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Sample records for chars

  1. Effect of pyrolysis conditions and composition on the char structure and char yield of biomass chars

    DEFF Research Database (Denmark)

    Trubetskaya, Anna; Steibel, Markus; Spliethoff, Hartmut; Barsberg, Søren Talbro; Jensen, Peter Arendt; Glarborg, Peter

    electron microscopy indicated different types of softening and melting of the biomass chars at all applied temperatures, heating rates and holding times, except for rice husks, which formed chars with a structure similar to the parent fuel. The char particles generated at high pyrolysis temperatures had......The char yield as well as physical and chemical structure of chars generated from different types of biomass divided into five different particle size fractions from 50μm to 1mm were studied to better understand the influences of holding time, final temperatures and heating rates on the pyrolysis...... structural changes. A significantly different char yield was observed between heating rates 10 K/s and 1000 K/s. For heating rates > 600 K/s a similar biomass char yield was obtained. Overall, it was found that the final temperature has more influence on the char yield than the heating rate. The scanning...

  2. Overview of the CHarring Ablator Response (CHAR) Code

    Science.gov (United States)

    Amar, Adam J.; Oliver, A. Brandon; Kirk, Benjamin S.; Salazar, Giovanni; Droba, Justin

    2016-01-01

    An overview of the capabilities of the CHarring Ablator Response (CHAR) code is presented. CHAR is a one-, two-, and three-dimensional unstructured continuous Galerkin finite-element heat conduction and ablation solver with both direct and inverse modes. Additionally, CHAR includes a coupled linear thermoelastic solver for determination of internal stresses induced from the temperature field and surface loading. Background on the development process, governing equations, material models, discretization techniques, and numerical methods is provided. Special focus is put on the available boundary conditions including thermochemical ablation and contact interfaces, and example simulations are included. Finally, a discussion of ongoing development efforts is presented.

  3. Effective Diffusion Coefficients in Coal Chars

    DEFF Research Database (Denmark)

    Johnsson, Jan Erik; Jensen, Anker

    2001-01-01

    Knowledge of effective diffusion coefficients in char particles is important when interpreting experimental reactivity measurements and modeling char combustion or NO and N2O reduction. In this work, NO and N2O reaction with a bituminous coal char was studied in a fixed-bed quartz glass reactor....... In the case of strong pore diffusion limitations, the error in the interpretation of experimental results using the mean pore radius could be a factor of 5 on the intrinsic rate constant. For an average coal char reacting with oxygen at 1300 K, this would be the case for particle sizes larger than...

  4. Defluoridation with Locally Produced Thai Bone Char

    Directory of Open Access Journals (Sweden)

    Yothin Mutchimadilok

    2014-01-01

    Full Text Available The fluoride sorption ability of a locally available bone char is quantified. Both a synthetic solution and natural groundwater samples from several sites are studied and compared to Indian bone char, which is widely accepted and used successfully in India and elsewhere. The Freundlich and Langmuir sorption isotherms were used to quantify sorption properties. Results show that the Thai bone char is as effective as the Indian bone char for removing fluoride from contaminated water, despite the more rigid physical and social constraints found in rural Thailand. Sorption studies with fluoride-contaminated natural groundwater samples also show that chlorides, nitrates, and sulfates had little effect on the removal of fluoride by the homemade bone char.

  5. Combustion of char from plastic wastes pyrolysis

    Science.gov (United States)

    Saptoadi, Harwin; Rohmat, Tri Agung; Sutoyo

    2016-06-01

    A popular method to recycle plastic wastes is pyrolysis, where oil, gas and char can be produced. These products can be utilized as fuels because they are basically hydrocarbons. The research investigates char properties, including their performance as fuel briquettes. There are 13 char samples from PE (Polyethylene) pyrolyzed at temperatures of around 450 °C, with and without a catalyst. Some of the samples were obtained from PE mixed with other types, such as Polystyrene (PS), Polypropylene (PP), Polyethylene Terephthalate (PET), and Others. Char properties, such as moisture, ash, volatile matter, and fixed carbon contents, are revealed from the proximate analysis, whereas calorific values were measured with a bomb calorimeter. Briquettes are made by mixing 4 g of char with 0.5 - 1 g binder. Briquettes are hollow cylinders with an outer and inner diameter of around 1.75 cm and 0.25 cm, respectively. Combustion is carried out in a furnace with wall temperatures of about 230°C and a constant air velocity of 0.7 m/s. Five out of 13 char briquettes are not feasible because they melt during combustion. Briquettes made from 100% PE wastes burn in substantially shorter duration than those from mixed plastic wastes. Char #1 and #5 are excellent due to their highest energy release, whereas #10 show the worst performance.

  6. Kinetic Analysis of Char Thermal Deactivation

    DEFF Research Database (Denmark)

    Zolin, Alfredo; Jensen, Anker; Dam-Johansen, Kim

    2001-01-01

    and demineralized Dietz from USA, and two alternative fuels, Danish leached straw and petroleum coke, were used in the experiments. The coal chars from demineralized Dietz, Illinois no. 6, and Cerrejon deactivate readily, whereas petroleum coke and Blair Athol show a relative high resistance to...... deactivation. Leached straw deactivates significantly, but maintains at any heat-treatment temperature a higher reactivity than the other chars. The inertinite-rich coal Blair Athol is more resistant to deactivation than two vitrinite-rich coals of the same ASTM rank, Cerrejon and Illinois no. 6. Cerrejon and...... Illinois no. 6 chars prepared in the TGA at 1673 K show a much lower reactivity than carbon extracts from boilers operated with these coals, possibly owing to enhanced annealing conditions in the TGA, such as low heating rates, relatively high temperatures, and long holding times. Based on the char...

  7. Modeling pyrolysis of charring material in fire

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    A modified model of pyrolysis for charring materials in fire has been proposed in this note. In this model some special factors which show the effect on pyrolysis are considered, i.e. heat loss by convection and radiation caused by surface temperature rise and shrinkage of char surface are considered. Experimental device is designed specially for validating the reliability of the model. Effects of density of materials and heat radiation on pyrolysis of materials have also been investigated.

  8. Kinetic Analysis of Char Thermal Deactivation

    DEFF Research Database (Denmark)

    Zolin, Alfredo; Jensen, Anker; Dam-Johansen, Kim

    2001-01-01

    . Leached straw deactivates significantly, but maintains at any heat-treatment temperature a higher reactivity than the other chars. The inertinite-rich coal Blair Athol is more resistant to deactivation than two vitrinite-rich coals of the same ASTM rank, Cerrejon and Illinois no. 6. Cerrejon and Illinois...... that TGA experiments can be used to capture the reactivity differences of chars observed in combustion facilities....

  9. Microbial oxidation of pyrrhotites in coal chars

    Science.gov (United States)

    Miller, K.W.; Risatti, J.B.

    1988-01-01

    The ability of Thiobacillus ferrooxidans to oxidize pyrrhotite minerals occurring in coal chars was investigated, to evaluate the feasibility of microbial char desulphurization. Bio-oxidation of pyrrhotites in chars produced by two different processes was demonstrated conclusively. Microbial removal of sulphur from a char and its parent coal proceeded at the rate of 3.5% and 12% day-1, respectively with a total of 48% and 81% removal after 27 days. The pH of shake flask cultures containing the coal dropped naturally to a final value of 2.2, while the pH of cultures containing the corresponding char rose and had to be lowered artificially with additional acid. Amending char cultures with elemental sulphur to increase acidity upon bio-oxidation and prevent precipitation of ferric iron was successful; however, the extent of pyrrhotite removal, as demonstated by X-ray diffraction analysis, was not improved. As yet, there is no explanation for the failure of microbial removal of pyrrhotitic sulphur to go to completion. ?? 1988.

  10. Changes in char reactivity due to char-oxygen and char-steam reactions using Victorian brown coal in a fixed-bed reactor

    Institute of Scientific and Technical Information of China (English)

    Shu Zhang; Yonggang Luo; Chunzhu Li; Yonggang Wang

    2015-01-01

    This study was to examine the influence of reactions of char–O2 and char–steam on the char reactivity evolution. A newly-designed fixed-bed reactor was used to conduct gasification experiments using Victorian brown coal at 800 °C. The chars prepared from the gasification experiments were then collected and subjected to reactivity characterisation (ex-situ reactivity) using TGA (thermogravimetric analyser) in air. The results indicate that the char reactivity from TGA was generally high when the char experienced intensive gasification reactions in 0.3%O2 in the fixed-bed reactor. The addition of steam into the gasification not only enhanced the char conversion sig-nificantly but also reduced the char reactivity dramatical y. The curve shapes of the char reactivity with involve-ment of steam were very different from that with O2 gasification, implying the importance of gasifying agents to char properties.

  11. Char characterisation and its application in a coal burnout mode

    Energy Technology Data Exchange (ETDEWEB)

    Michael Cloke; Tao Wu; Richelieu Barranco; Ed Lester [University of Nottingham, Nottingham (United Kingdom). Nottingham Fuel and Energy Centre, School of Chemical, Environmental and Mining Engineering, Coal Technology Research Group

    2003-10-01

    In this study, char image analysis techniques have been employed to investigate the morphology of chars obtained from a Drop-Tube furnace. Char image analysis results have been incorporated as inputs to a char burnout model based on Hurt's CBK model. It has been observed that the char combustion rate was strongly affected by char structural parameters and the inclusion of char morphology has led to a better prediction of char burnout. It has also been suggested by the model that the inclusion of ash inhibition overestimates the resistance attributed by ash film and the consideration of ash film resistance should be undertaken in a different way to give a better prediction at the later stages of char combustion. 12 refs., 13 figs., 5 tabs.

  12. Mineral matter effects on char structural evolution and oxidation kinetics during coal char combustion

    Energy Technology Data Exchange (ETDEWEB)

    Lunden, M.; Yang, N.; Headley, T.; Shaddix, C.; Hardesty, D.

    1997-10-01

    The authors report on recent investigations of the evolution of char structure during carbon burnout and the role of mineral matter in determining this structure. Char samples collected in a carefully controlled laminar, flame-supported entrained flow reactor have been characterized using a number of microscopy tools. Observations of the inorganic structure of chars produced at a variety of combustion conditions are coupled with in-situ optical measurements of the char particle population with an eye towards identifying the mechanism of mineral interaction and its effects on carbon burnout kinetics during pulverized coal char combustion. Preliminary results show a surprising amount of inorganic mineral in solid solution with the carbonaceous matrix. This intimate mixing of organic and inorganic constituents may affect reactivity by both blocking oxygen access to active carbon sites and influencing the microscopic carbon structure that evolves during combustion.

  13. Stereoscopic pyrometer for char combustion characterization.

    Science.gov (United States)

    Schiemann, M; Vorobiev, N; Scherer, V

    2015-02-10

    For many pulverized fuels, especially coal and biomass, char combustion is the time determining step. Based on intensified ICCD cameras, a novel setup has been developed to study pulverized fuel combustion, mainly in a laminar flow reactor. For char burning characterization, the typical measurement parameters are particle temperature, size, and velocity. The working principle of the camera setup is introduced and its capabilities are discussed by examination of coal particle combustion under CO(2)-enriched, so-called oxy-fuel atmospheres with varying O(2) content. PMID:25968027

  14. Active sites in char gasification: Final technical report

    Energy Technology Data Exchange (ETDEWEB)

    Wojtowicz, M.; Lilly, W.D.; Perkins, M.T.; Hradil, G.; Calo, J.M.; Suuberg, E.M.

    1987-09-01

    Among the key variables in the design of gasifiers and combustors is the reactivity of the chars which must be gasified or combusted. Significant loss of unburned char is unacceptable in virtually any process; the provision of sufficient residence time for complete conversion is essential. A very wide range of reactivities are observed, depending upon the nature of the char in a process. The current work focuses on furthering the understanding of gasification reactivities of chars. It has been well established that the reactivity of char to gasification generally depends upon three principal factors: (1) the concentration of ''active sites'' in the char; (2) mass transfer within the char; and (3) the type and concentration of catalytic impurities in the char. The present study primarily addresses the first factor. The subject of this research is the origin, nature, and fate of active sites in chars derived from parent hydrocarbons with coal-like structure. The nature and number of the active sites and their reactivity towards oxygen are examined in ''model'' chars derived from phenol-formaldehyde type resins. How the active sites are lost by the process of thermal annealing during heat treatment of chars are studied, and actual rate for the annealing process is derived. Since intrinsic char reactivities are of primary interest in the present study, a fair amount of attention was given to the model char synthesis and handling so that the effect of catalytic impurities and oxygen-containing functional groups in the chemical structure of the material were minimized, if not completely eliminated. The project would not be considered complete without comparing characteristic features of synthetic chars with kinetic behavior exhibited by natural chars, including coal chars.

  15. Experimental Investigation of NO from Pulverized Char Combustion

    DEFF Research Database (Denmark)

    Jensen, Lars Skaarup; Jannerup, Hans Erik; Glarborg, Peter; Jensen, Anker; Dam-Johansen, Kim

    2001-01-01

    previously reported in literature, but are consistent with reburn-type experiments employing char as fuel. This discrepancy is mainly attributed to rapid char deactivation prior to measuring of NO reduction rates in previous determinations. Shortly after pyrolysis, the effective NO-char reaction rate for...

  16. Phosphorus recovery from sewage sludge char ash

    NARCIS (Netherlands)

    Atienza-Martinez, M.; Gea, G.; Arauzo, J.; Kersten, S.R.A.; Kootstra, A.M.J.

    2014-01-01

    Phosphorus was recovered from the ash obtained after combustion at different temperatures (600 °C, 750 °C and 900 °C) and after gasification (at 820 °C using a mixture of air and steam as fluidising agent) of char from sewage sludge fast pyrolysis carried out at 530 °C. Depending on the leaching con

  17. Ablating and charring of heat shield materials

    Energy Technology Data Exchange (ETDEWEB)

    Rahimian, M.H.; Shabani, M.R. [Univ. of Tehran, Faculty of Engineering, Mechanical Engineering Dept., Tehran (Iran, Islamic Republic of)]. E-mail: rahimyan@ut.ac.ir; shubani@me.ut.ac.ir

    2003-07-01

    The objective of this research is to estimate ablating and charring of heat shield materials in severe aero thermal / erosive environments. This requires an accurate and rapid technique for its serious heat transfer with moving boundary. Aerodynamic heating is obtained by an explicit relation. Fully implicit method is used for heat transfer calculation. Moving boundary is captured by VOF method. Thickness of heat shield, temperature of moving surface and radiation heat is presented. The results are in good agreement with other calculations. (author)

  18. Ablating and charring of heat shield materials

    International Nuclear Information System (INIS)

    The objective of this research is to estimate ablating and charring of heat shield materials in severe aero thermal / erosive environments. This requires an accurate and rapid technique for its serious heat transfer with moving boundary. Aerodynamic heating is obtained by an explicit relation. Fully implicit method is used for heat transfer calculation. Moving boundary is captured by VOF method. Thickness of heat shield, temperature of moving surface and radiation heat is presented. The results are in good agreement with other calculations. (author)

  19. Kinetics and Mechanisms of NO(x) - Char Reduction.

    Energy Technology Data Exchange (ETDEWEB)

    Suurerg, E.M.; Lilly, W.D.; Aarna, I.

    1997-12-31

    Most industrially important carbons are produced from naturally occurring materials such as coal, oil, peat or wood by some form of thermal process. Chars are obtained from those natural materials as a residue after removal of the volatile matter. Chars (prepared from coal or other organic precursors) are non-graphitizable carbons, meaning that they cannot be transformed into graphitic carbon. Chars are comprised of elementary crystallites in parallel layers which are randomly oriented with respect to each other and are crosslinked together through weak bonds. Voids between crystallites determine the porosity of the char, and this plays an important role in char gasification behavior. Chars usually contain a pore size distribution, in which the larger macro- and mesopores play an important role in transport of reactants into the much smaller micropores, in which most gasification and combustion take place. Therefore, the effectiveness of micropores in gasification depends heavily on the numbers of meso- and macropores.

  20. Development, Verification and Validation of Enclosure Radiation Capabilities in the CHarring Ablator Response (CHAR) Code

    Science.gov (United States)

    Salazar, Giovanni; Droba, Justin C.; Oliver, Brandon; Amar, Adam J.

    2016-01-01

    With the recent development of multi-dimensional thermal protection system (TPS) material response codes including the capabilities to account for radiative heating is a requirement. This paper presents the recent efforts to implement such capabilities in the CHarring Ablator Response (CHAR) code developed at NASA's Johnson Space Center. This work also describes the different numerical methods implemented in the code to compute view factors for radiation problems involving multiple surfaces. Furthermore, verification and validation of the code's radiation capabilities are demonstrated by comparing solutions to analytical results, to other codes, and to radiant test data.

  1. Production of activated carbon from TCR char

    Science.gov (United States)

    Stenzel, Fabian; Heberlein, Markus; Klinner, Tobias; Hornung, Andreas

    2016-04-01

    The utilization of char for adsorptive purposes is known since the 18th century. At that time the char was made of wood or bones and used for decoloration of fluids. In the 20th century the production of activated carbon in an industrial scale was started. The today's raw materials for activated carbon production are hard coal, peat, wood or coconut shells. All these materials entail costs especially the latter. Thus, the utilization of carbon rich residues (biomass) is an interesting economic opportunity because it is available for no costs or even can create income. The char is produced by thermo-catalytic reforming (TCR®). This process is a combination of an intermediate pyrolysis and subsequently a reforming step. During the pyrolysis step the material is decomposed in a vapor and a solid carbon enriched phase. In the second step the vapor and the solid phase get in an intensive contact and the quality of both materials is improved via the reforming process. Subsequently, the condensables are precipitated from the vapor phase and a permanent gas as well as oil is obtained. Both are suitable for heat and power production which is a clear advantage of the TCR® process. The obtained biochar from the TCR® process has special properties. This material has a very low hydrogen and oxygen content. Its stability is comparable to hard coal or anthracite. Therefore it consists almost only of carbon and ash. The latter depends from input material. Furthermore the surface structure and area can be influenced during the reforming step. Depending from temperature and residence time the number of micro pores and the surface area can be increased. Preliminary investigations with methylene blue solution have shown that a TCR® char made of digestate from anaerobic digestion has adsorptive properties. The decoloration of the solution was achieved. A further influencing factor of the adsorption performance is the particle size. Based on the results of the preliminary tests a

  2. Active carbons from low temperature conversion chars

    International Nuclear Information System (INIS)

    Hulls obtained from the fruits of five tropical biomass have been subjected to low temperature conversion process and their chars activated by partial physical gasification to produce active carbons. The biomass are T. catappa, B. nitida, L leucophylla, D. regia and O. martiana. The bulk densities of the samples ranged from 0.32 g.cm3 to 0.52 g.cm3. Out of the samples T. catappa recorded the highest cellulose content (41.9 g.100g-1), while O. martiana contained the highest lignin content (40.7 g.100g-1). The ash of the samples were low (0.5 - 4.4%). The percentage of char obtained after conversion were high (33.7% - 38.6%). Active carbons obtained from T. catappa, D. regia and O. martiana, recorded high methylene blue numbers and iodine values. They also displayed good micro- and mesostructural characteristics. Micropore volume (Vmicro) was between 0.33cm3.g-1 - 0.40cm3.g-1, while the mesopore volume(Vmeso) was between 0.05 cm3.g-1 - 0.07 cm3.g-1. The BET specific surface exceeds 1000 m2.g-1. All these values compared favourably with high grade commercial active carbons. (author)

  3. Evaluation of solid fuel char briquettes from human waste.

    Science.gov (United States)

    Ward, Barbara J; Yacob, Tesfayohanes W; Montoya, Lupita D

    2014-08-19

    The developing world faces dual crises of escalating energy demand and lack of urban sanitation infrastructure that pose significant burdens on the environment. This article presents results of a study evaluating the feasibility of using human feces-derived char as a solid fuel for heating and cooking and a potential way to address both crises. The study determined the energy content and the elemental composition of chars pyrolyzed at 300, 450, and 750 °C. Fecal chars made at 300 °C were found to be similar in energy content to wood chars and bituminous coal, having a heating value of 25.6 ± 0.08 MJ/kg, while fecal chars made at 750 °C had an energy content of 13.8 ± 0.48 MJ/kg. The higher heating values of the studied chars were evaluated using their elemental composition and a published predictive model; results found good agreement between the measured and predicted values. Fecal chars made at low temperatures were briquetted with molasses/lime and starch binders. Briquettes made with 10% starch had an average impact resistance index of 79 and a higher heating value of 25 MJ/kg. These values are comparable to those of commercial charcoal briquettes, making fecal char briquettes a potential substitute that also contributes to the preservation of the environment. PMID:25020243

  4. Gas cleaning with hot char beds studied by stable isotopes

    DEFF Research Database (Denmark)

    Egsgaard, Helge; Ahrenfeldt, Jesper; Ambus, Per; Schaumburg, K.; Henriksen, Ulrik Birk

    2014-01-01

    The chemistry taking place in a high temperature char bed used for binding aromatic tar compounds has been studied in detail. 13C labelled tar compounds were used to trace the incorporation into the char bed using isotope ratio mass spectrometry (IRMS) and GC-MS. Furthermore, compounds labelled...

  5. NO Reduction over Biomass and Coal Char during Simultaneous Combustion

    DEFF Research Database (Denmark)

    Zhao, Ke; Glarborg, Peter; Jensen, Anker Degn

    2013-01-01

    This paper reports an experimental study of NO reduction over chars of straw, bark, bituminous coal, and lignite. The experiments were performed in a fixed bed reactor in the temperature range 850–1150 °C. The chars were generated by in situ pyrolysis at the reaction temperature to minimize further...

  6. Continuum radiation analysis of size distributed ensembles of char particles

    Energy Technology Data Exchange (ETDEWEB)

    Zarkova, L.P.; Pirgov, P.S. [Bulgarian Academy of Sciences, Sofia (Bulgaria). Inst. of Electronics; Vasilieva, I.A. [Inst. of High Temperatures, Moscow (Russian Federation); Banin, V.E.; Moors, J.H.J.; Veefkind, A. [Technische Hogeschool Eindhoven (Netherlands). Lab. for Fluid Dynamics and Heat Transfer

    1997-12-31

    Continuum radiation emitted by char particles has been collected during shock tube experiments. Since the particles have different sizes their cooling rates, their temperatures and emissivities are different. A method is presented to determine the kinetic parameters of char combustion taking into account this complication, when the initial size distribution is determined independently. Results are presented and their accuracy will be discussed. (orig.)

  7. CHARCOAL PACKED FURNACE FOR LOW-TECH CHARRING OF BONE

    DEFF Research Database (Denmark)

    Jacobsen, P.; Dahi, Elian

    1997-01-01

    A low-tech furnace for charring of raw bone using char coal is developed and tested. The furnace consists of a standard oil drum, fitted with simple materials as available in every market in small towns in developing counties. 80 kg of raw bone and 6 kg of charcoal are used for production of 50 k...

  8. Compilation of Sandia coal char combustion data and kinetic analyses

    Energy Technology Data Exchange (ETDEWEB)

    Mitchell, R.E.; Hurt, R.H.; Baxter, L.L.; Hardesty, D.R.

    1992-06-01

    An experimental project was undertaken to characterize the physical and chemical processes that govern the combustion of pulverized coal chars. The experimental endeavor establishes a database on the reactivities of coal chars as a function of coal type, particle size, particle temperature, gas temperature, and gas and composition. The project also provides a better understanding of the mechanism of char oxidation, and yields quantitative information on the release rates of nitrogen- and sulfur-containing species during char combustion. An accurate predictive engineering model of the overall char combustion process under technologically relevant conditions in a primary product of this experimental effort. This document summarizes the experimental effort, the approach used to analyze the data, and individual compilations of data and kinetic analyses for each of the parent coals investigates.

  9. Disintegration of beech wood char during thermal conversion

    DEFF Research Database (Denmark)

    Hindsgaul, Claus

    In the present work the processes occurring in the structures of slowly pyrolysed beech wood char during thermal gasification have been investigated. Emphasis was put on physical changes and gas transport properties during conversion. The highly anisotropic structure of wood was preserved in its...... char. Direct observation of the microscopic char structures during gasification in CO2 at 735 QC showed that the basic structure was nearly intact up to degrees of conversion of 0.6—0.7. Uni-axial measurements of diffusion coefficients and permeabilities with a Wicke-Kallenbach cell revealed...... differences of 3—4 orders of magnitude between the longitudinal and other directions in freshly pyrolysed beech wood char. Diffusion in the longitudinal direction of the beech wood char before gasification corresponded to direct, unobstructed diffusion through its vessel cells. Radial and tangential diffusion...

  10. Development and Verification of Enclosure Radiation Capabilities in the CHarring Ablator Response (CHAR) Code

    Science.gov (United States)

    Salazar, Giovanni; Droba, Justin C.; Oliver, Brandon; Amar, Adam J.

    2016-01-01

    With the recent development of multi-dimensional thermal protection system (TPS) material response codes, the capability to account for surface-to-surface radiation exchange in complex geometries is critical. This paper presents recent efforts to implement such capabilities in the CHarring Ablator Response (CHAR) code developed at NASA's Johnson Space Center. This work also describes the different numerical methods implemented in the code to compute geometric view factors for radiation problems involving multiple surfaces. Verification of the code's radiation capabilities and results of a code-to-code comparison are presented. Finally, a demonstration case of a two-dimensional ablating cavity with enclosure radiation accounting for a changing geometry is shown.

  11. Dwarf char, a new form of chars (the genus Salvelinus) in Lake Kronotskoe

    Science.gov (United States)

    Pavlov, S.D.; Pivovarov, E.A.; Ostberg, C.O.

    2012-01-01

    Lake Kronotskoe is situated in the Kronotskii State Nature Reserve and is a unique natural heritage of Kamchatka. The lake–river system of the reserve includes numerous springs and small streams and three large inflowing rivers, Listvennichnaya, Unana, and Uzon, which form the main bays of Lake Kronotskoe; one river (Kronotskaya) flows from the lake. This river is characterized by several rapids, which are assumed to be unsurmountable barriers for fish migration. The ichthyofauna of the lake has been isolated for a long time, and some endemic fishes appeared, including char of the genus Salvelinus and the residential form of red salmon Oncorhynchus nerka (the local name is kokanee). These species are perfect model objects to study microevolution processes. Char of Lake Kronotskoe are characterized by significant polymorphism and plasticity [1–3]; therefore, they are extremely valuable for studying the processes of speciation and form development. That is why the populations of char in Lake Kronotskoe are unique and attract special attention of researchers. 

  12. Oxidation behavior of biomass chars: pectin and Populus deltoides

    Energy Technology Data Exchange (ETDEWEB)

    Hong-Shig Shim; Mohammad R. Hajaligol; Vicki L. Baliga [Philip Morris USA, Richmond, VA (United States). Research Center

    2004-08-01

    Biomass chars of pectin and cotton wood (Populus deltoides) were prepared by using a heating rate of about 1{sup o}C/s, peak pyrolysis temperatures of 400-800{sup o}C, and residence times of 10-60 min at peak temperatures. Char samples were pyrolyzed in a helium atmosphere using a thermogravimetric analyzer (TGA). Oxidation reactivity measurements of the same char samples in the TGA were collected after converting the helium atmosphere to an oxygen containing atmosphere. Reactivities were measured using an isothermal method at various reaction temperatures from 400 to 700{sup o}C and oxygen concentrations of 2-21%. Oxidation kinetic parameters such as apparent reaction order and apparent activation energies were obtained. Scanning electron microscopy (SEM) was employed to study morphological and structural development in the char samples as a function of heat treatment temperature. An interesting morphological development on the surface of the char was observed by SEM, which showed evolution of vesicle formation and whisker growth as heat treatment temperatures increased. Its implication on char reactivity is discussed. Preliminary results showed decreasing reactivity with increasing peak heat treatment temperatures. Char reactivity was affected more by the heat treatment temperature than by the hold times (10-60 min). 15 refs., 12 figs., 3 tabs.

  13. A burnout prediction model based around char morphology

    Energy Technology Data Exchange (ETDEWEB)

    Tao Wu; Edward Lester; Michael Cloke [University of Nottingham, Nottingham (United Kingdom). School of Chemical, Environmental and Mining Engineering

    2006-05-15

    Several combustion models have been developed that can make predictions about coal burnout and burnout potential. Most of these kinetic models require standard parameters such as volatile content and particle size to make a burnout prediction. This article presents a new model called the char burnout (ChB) model, which also uses detailed information about char morphology in its prediction. The input data to the model is based on information derived from two different image analysis techniques. One technique generates characterization data from real char samples, and the other predicts char types based on characterization data from image analysis of coal particles. The pyrolyzed chars in this study were created in a drop tube furnace operating at 1300{sup o}C, 200 ms, and 1% oxygen. Modeling results were compared with a different carbon burnout kinetic model as well as the actual burnout data from refiring the same chars in a drop tube furnace operating at 1300{sup o}C, 5% oxygen, and residence times of 200, 400, and 600 ms. A good agreement between ChB model and experimental data indicates that the inclusion of char morphology in combustion models could well improve model predictions. 38 refs., 5 figs., 6 tabs.

  14. A burnout prediction model based around char morphology

    Energy Technology Data Exchange (ETDEWEB)

    T. Wu; E. Lester; M. Cloke [University of Nottingham, Nottingham (United Kingdom). Nottingham Energy and Fuel Centre

    2005-07-01

    Poor burnout in a coal-fired power plant has marked penalties in the form of reduced energy efficiency and elevated waste material that can not be utilized. The prediction of coal combustion behaviour in a furnace is of great significance in providing valuable information not only for process optimization but also for coal buyers in the international market. Coal combustion models have been developed that can make predictions about burnout behaviour and burnout potential. Most of these kinetic models require standard parameters such as volatile content, particle size and assumed char porosity in order to make a burnout prediction. This paper presents a new model called the Char Burnout Model (ChB) that also uses detailed information about char morphology in its prediction. The model can use data input from one of two sources. Both sources are derived from image analysis techniques. The first from individual analysis and characterization of real char types using an automated program. The second from predicted char types based on data collected during the automated image analysis of coal particles. Modelling results were compared with a different carbon burnout kinetic model and burnout data from re-firing the chars in a drop tube furnace operating at 1300{sup o}C, 5% oxygen across several residence times. An improved agreement between ChB model and DTF experimental data proved that the inclusion of char morphology in combustion models can improve model predictions. 27 refs., 4 figs., 4 tabs.

  15. Study on CO2 gasification reactivity and physical characteristics of biomass, petroleum coke and coal chars.

    Science.gov (United States)

    Huo, Wei; Zhou, Zhijie; Chen, Xueli; Dai, Zhenghua; Yu, Guangsuo

    2014-05-01

    Gasification reactivities of six different carbonaceous material chars with CO2 were determined by a Thermogravimetric Analyzer (TGA). Gasification reactivities of biomass chars are higher than those of coke and coal chars. In addition, physical structures and chemical components of these chars were systematically tested. It is found that the crystalline structure is an important factor to evaluate gasification reactivities of different chars and the crystalline structures of biomass chars are less order than those of coke and coal chars. Moreover, initial gasification rates of these chars were measured at high temperatures and with relatively large particle sizes. The method of calculating the effectiveness factor η was used to quantify the effect of pore diffusion on gasification. The results show that differences in pore diffusion effects among gasification with various chars are prominent and can be attributed to different intrinsic gasification reactivities and physical characteristics of different chars. PMID:24642484

  16. Thermal analysis of charring materials based on pyrolysis interface model

    Directory of Open Access Journals (Sweden)

    Huang Hai-Ming

    2014-01-01

    Full Text Available Charring thermal protection systems have been used to protect hypersonic vehicles from high heat loads. The pyrolysis of charring materials is a complicated physical and chemical phenomenon. Based on the pyrolysis interface model, a simulating approach for charring ablation has been designed in order to obtain one dimensional transient thermal behavior of homogeneous charring materials in reentry capsules. As the numerical results indicate, the pyrolysis rate and the surface temperature under a given heat flux rise abruptly in the beginning, then reach a plateau, but the temperature at the bottom rises very slowly to prevent the structural materials from being heated seriously. Pyrolysis mechanism can play an important role in thermal protection systems subjected to serious aerodynamic heat.

  17. Combustion reactivity of chars from copyrolysis of coal with coke-oven gas

    Energy Technology Data Exchange (ETDEWEB)

    Liao Hongqiang; Sun Chenggong; Li Baoqing [Chinese Academy of Sciences, Taiyuan (China). State Key Lab. of Coal Conversion

    1997-12-31

    The combustion reactivity of char from pyrolysis of Xianfeng lignite with coke-oven gas (COG) is related to the pyrolysis pressure and heating rate. Decreasing pressure and increasing heating rate enhance the char yields and combustion reactivity. The combustion reactivities of char from coal pyrolysis with COG nearly reach to that of char from hydropyrolysis, but lower than those of char from coal pyrolysis under N{sub 2}. (orig.)

  18. Charring of wood with thermal radiation, 1: Ignition of wood during charring

    International Nuclear Information System (INIS)

    The charring mechanism of wood with thermal radiation has been studied, and this paper describes the ignition of the wood which took place in the course of charring. The species tested were sugi (Cryptomeria japonica D. Don), hinoki (Chamaecyparis obtusa (S. and Z. ) Endl.), hannoki (Alnus japonica Steud.), aodamo (Fraxinus lanuginosa Koidz.), buna(Fagus crenata Bl.), and akagashi (Quercus acuta Thunb.). The thicknesses of specimens was 10 mm or more. The specimens were heated at irradiances of 20, 30, or 40 kW/m2 by means of an ISO 5657 furnace. Ignition times and internal temperatures of specimens were measured. The outlines of results are as follows: 1) No effects of the specimen thicknesses were observed on the ignitions, 2) Linear relationships were found between reciprocals of irradiance and logarithms of ignition times, 3) The ignition times approximately increased linearly with increases in sample densities, and the effects of density as well as irradiance are theoretically explained, 4) Temperature profiles suggest that surface temperatures approach to approximately the same values of the times of ignitions independently of the densities, 5) Ignitions are controlled exclusively by pyrolysis of the surface layers, namely, properties of the surface layers, 6) The calculated values of heat transferred to specimens until ignitions increased with increases in densities and decreases in irradiance which meant that ignition was to be understood not as thermodynamic but as a kinetic phenomenon. (author)

  19. Coal and char properties in high temperature entrained flow gasification

    International Nuclear Information System (INIS)

    With the objective to measure coal conversion at realistic operation conditions the Pressurised High Temperature Entrained Flow Reactor (PiTER) is developed. The pyrolysis of Rhenish lignite is studied at temperatures up to 1600 °C and pressures up to 2.5 MPa. At longer residence time (above 1.5 s) volatile yield is 68 wt% and independent of temperature and pressure. Char samples are extracted from the hot reaction zone and their reactivity is analysed by weight loss in TGA experiments at defined conditions. Furthermore, specific char surface area is measured. At 1200 °C the intrinsic reactivity of char decreases by a factor of almost 7 from 0.5 s to 2 s residence time, but surface area (approximately 500 m2/g) is hardly affected. At 1400 °C and 1600 °C, the intrinsic reactivity also decreases, but simultaneously the surface area is reduced to below 300 m2/g. The difference in deactivation can only be explained by two different mechanisms: (i) experiments at 1200 °C are below the ash fusion temperature and graphitisation at the char surface may lead to a reorganisation of carbon atoms; (ii) above the ash fusion temperature, the melting of mineral matter additionally blocks the micropore structure and results in a loss of specific surface area. -- Highlights: ► Development of a novel pilot scale entrained flow research reactor. ► Pyrolysis at up to 1600 °C and up to 2.5 MPa under entrained flow conditions. ► Surface area of char significantly decreases above the ash melting temperature. ► Intrinsic reactivity of char is dependent on heat treatment severity. ► Thermal annealing affects char reactivity, even at short residence time.

  20. Bio-char from treated and untreated oil palm fronds

    Science.gov (United States)

    Sulaiman, Fauziah; Abdullah, Nurhayati; Rahman, Aizuddin Abdul

    2013-05-01

    The palm oil industry generates almost 94% of biomass in Malaysia, while other agricultural and forestry by-products contribute the remaining of 6%. Oil palm fronds (OPF) are estimated to be the highest available biomass amounting to 44.84 million tonnes in Malaysia. However, studies on OPF for thermochemical conversion technology which has good potential for energy conversion are still lacking. In this work, pyrolysis of OPF is conducted by using a fixed bed reactor. Samples were carbonized at slow pyrolysis temperature of around 300 to 500°C with heating rate of 10°C min-1. In addition, samples were treated for 20 min with distilled water at ambient temperature to reduce the ash content. Effectiveness of pre-treatment can be determined by observing the percentage of ash content reduction of each sample after undergoing washing pre-treatment. At 300°C, the char yields of the untreated OPF were slightly higher at 50.95% compared to the treated sample at 49.77%. Approximately all bio-char from the treated samples have better high heating value (HHV) of around 18-20 MJ kg-1 compared to the untreated samples. Besides that, all treated OPF char is more carbon rich and considered to be environmental friendly due to its low nitrogen content compared to the untreated OPF char. In this work, microscopic analysis of OPF bio-char were also studied by observing and evaluating their structure surface and morphology.

  1. Preparation and characterization of activated carbon from demineralized tyre char

    Science.gov (United States)

    Manocha, S.; Prasad, Guddu R.; Joshi, Parth.; Zala, Ranjitsingh S.; Gokhale, Siddharth S.; Manocha, L. M.

    2013-06-01

    Activated carbon is the most adsorbing material for industrial waste water treatment. For wider applications, the main consideration is to manufacture activated carbon from low cost precursors, which are easily available and cost effective. One such source is scrap tyres. Recently much effort has been devoted to the thermal degradation of tyres into gaseous and liquid hydrocarbons and solid char residue, all of which have the potential to be processed into valuable products. As for solid residue, char can be used either as low-grade reinforcing filler or as activated carbon. The product recovered by a typical pyrolysis of tyres are usually, 33-38 wt% pyrolytic char, 38-55 wt% oil and 10-30 wt% solid fractions. In the present work activated carbon was prepared from pyrolyzed tyre char (PC). Demineralization involves the dissolution of metal into acids i.e. HCl, HNO3 and H2SO4 and in base i.e. NaOH. Different concentration of acid and base were used. Sodium hydroxide showed maximum amount of metal oxide removal. Further the concentration of sodium hydroxide was varied from 1N to 6N. As the concentration of acid are increased demineralization increases. 6N Sodium hydroxide is found to be more effective demineralising agent of tyre char.

  2. Characterization of char from slow pyrolysis of sewage sludge.

    Science.gov (United States)

    Xu, Wen-Ying; Wu, Di

    2016-01-01

    The effects of final pyrolysis temperature Tend from 300 ºC to 550 ºC, heating rates β of 2 ºC/min, 3 ºC/min and 5 ºC/min, retention time RT from 45 min to 90 min, and the moisture content MC from 0 to 70% on characteristics of the pyrolysis char from sewage sludge were investigated using a tube furnace in this study. The resulting chars were characterized by sorption of nitrogen (surface area and pore volume). Their adsorption characteristics were evaluated via iodine value and methylene blue value. Either the pore structures or adsorption characteristics depend on the pyrolysis processing and moisture content of the sludge precursors. In terms of iodine value and surface area of the char, Tend of 450 ºC, RT of 75 min and β of 3 ºC/min proved the optimum combination of pyrolysis parameters. The chars have an undeveloped mesopore and macropore structure and a developed micropore structure. The sodium phenoxide adsorption equilibrium data fit well with the Langmuir model of adsorption, suggesting monolayer coverage of sodium phenoxide molecules at the surface of the char. Its adsorption mechanism is mainly physical in nature, enhanced by chemisorption. PMID:27191557

  3. Study on pore structure properties of steam activated biomass chars

    Energy Technology Data Exchange (ETDEWEB)

    Shu, Tong; Lu, Fei; Wang, Qinchao; Lu, Ping [Nanjing Normal Univ. (China). School of Energy and Mechanical Engineering

    2013-07-01

    Wheat straw and rice husk chars were prepared in a fixed bed reactor at different pyrolysis temperatures (673, 873 and 1,073K) and different pyrolysis procedure. The steam activated chars were also prepared in a fixed bed reactor at the following conditions: activation temperature is 1,073K, the flow rate of N{sub 2} is 5L/min, and N{sub 2} and H{sub 2}O molar ratio is 1:1. The specific surface area, pore structure and micro-morphology of different kinds of prepared biomass chars were measured by NOVA1000e analysis instrument and JSM-5610LV scanning electron microscopy (SEM), respectively. Results indicated that the internal structure was improved significantly by steam activation through enlarging the specific surface area and enriching the porosity. The wheat straw char prepared by both rapid pyrolysis at 873K and activation by steam is better than others, whose DR surface area increases from 3.10 to 1099.99m{sup 2}/g. The N{sub 2} adsorption volume of steam activated biomass chars has been significant promoted.

  4. Heat Transfer in a Fixed Bed of Straw Char

    DEFF Research Database (Denmark)

    Fjellerup, Jan Søren; Henriksen, Ulrik Birk; Jensen, Anker; Jensen, Peter Arendt; Glarborg, Peter

    2003-01-01

    A model for the thermal conductivity of a straw char bed has been developed. The model extends the work of Yagi and Kunii to describe heat transfer in a bed of cylinders, using a relationship between the interparticle distance and the external porosity. To verify the model, thermal conductivity...... experimental uncertainty over the range of conditions investigated. The heat transfer model was used in a parametric study to evaluate the effect of gas flow rate, particle diameter, porosity, and temperature on the thermal conductivity in a straw char bed....

  5. Formation, Structure and Properties of Amorphous Carbon Char from Polymer Materials in Extreme Atmospheric Reentry Environments

    Science.gov (United States)

    Lawson, John W.

    2010-01-01

    Amorphous carbonaceous char produced from the pyrolysis of polymer solids has many desirable properties for ablative heat shields for space vehicles. Molecular dynamics simulations are presented to study the transformation of the local atomic structure from virgin polymer to a dense, disordered char [1]. Release of polymer hydrogen is found to be critical to allow the system to collapse into a highly coordinated char structure. Mechanisms of the char formation process and the morphology of the resulting structures are elucidated. Thermal conductivity and mechanical response of the resulting char are evaluated [2]. During reenty, the optical response and oxidative reactivity of char are also important properties. Results of ab initio computations of char optical functions [3] and char reactivity [4] are also presented.

  6. Low-energy and chemical-free activation of pyrolytic tire char and its adsorption characteristics.

    Science.gov (United States)

    Quek, Augustine; Balasubramanian, Rajasekhar

    2009-06-01

    It is generally known that the solid char obtained from pyrolysis of scrap rubber tires can be used as an adsorbent for several applications such as wastewater treatment. In this study, scrap tires were first pyrolyzed under nitrogen (N2) or carbon dioxide (CO2) gas under various temperatures to produce char. The char was activated in situ by post-pyrolysis oxygenation (PPO) at different temperature ranges as soon as the pyrolysis process was completed. Elemental and spectroscopic analyses showed significant zinc content in the char after PPO. Batch-mode removal of aqueous copper (Cu) using the chars revealed that, for N2 and CO2, the optimum condition for pyrolysis was at 550 degrees C and for activation was from 550 to 250 degrees C. Although CO2-pyrolyzed char had lower Cu and lead (Pb) removal than N2-pyrolyzed char, it had higher char yields. For both N2- and CO2-pyrolyzed char, activation with PPO improved their heavy metal removal efficiencies significantly compared with unactivated char. PPO chars had much faster removal rates and higher Cu removal compared with both pyrolyzed, unactivated char and commercial activated carbons. PMID:19603742

  7. Experimental comparison of biomass chars with other catalysts for tar reduction

    NARCIS (Netherlands)

    Abu El-Rub, Z.; Bramer, E.A.; Brem, G.

    2008-01-01

    In this paper the potential of using biomass char as a catalyst for tar reduction is discussed. Biomass char is compared with other known catalysts used for tar conversion. Model tar compounds, phenol and naphthalene, were used to test char and other catalysts. Tests were carried out in a fixed bed

  8. Particle-based characterisation of pulverised coals and chars for carbon burnout studies

    Energy Technology Data Exchange (ETDEWEB)

    Gibbins, J.R.; Seitz, M.H.; Kennedy, S.M.; Beeley, T.J.; Riley, G.S. [Imperial College of Science, Technology and Medicine, London (United Kingdom). Mechanical Engineering Department

    1999-07-01

    The study of individual particle properties, as opposed to averaged behaviour of differing particles, was carried out for the combustion of coals and chars using optical microscopy and digital image processing. Chars from entrained flow reactors and corresponding pulverized fuel samples were characterized to examine possible char particle origins for real heterogeneous particles. 7 refs., 5 figs., 1 tab.

  9. Structural and Compositional Transformations of Biomass Chars during Fast Pyrolysis

    DEFF Research Database (Denmark)

    Trubetskaya, Anna; Steibel, Markus; Spliethoff, Hartmut;

    In this work the physical and chemical transformations of biomass chars during fast pyrolysis, considered as a 2nd stage of combustion, has been investigated. Seven biomasses containing different amount of ash and organic components were reacted at up to 1673 K with high heating rates in a wire...

  10. Heat Transfer in a Fixed Biomass Char Bed

    DEFF Research Database (Denmark)

    Fjellerup, Jan Søren; Henriksen, Ulrik Birk; Glarborg, P.; Jensen, A.; Arendt, P.

    2002-01-01

    A thermal conductivity model based on the Yagi and Kunii model together with a bed model was developed to describe the thermal conductivity of a straw char bed. The bed model describes the relationship between the distance between particles and the external porosity. To verify the model, thermal ...

  11. Properties of slurries made of fast pyrolysis oil and char or beech wood

    DEFF Research Database (Denmark)

    Trinh, Ngoc Trung; Jensen, Peter Arendt; Dam-Johansen, Kim;

    2014-01-01

    The properties of slurries made of pyrolysis oil mixed with wood, char or ground char were investigated with respect to phase transitions, rheological properties, elemental compositions, and energy density. Also the pumping properties of the slurries were investigated at temperatures of 25, 40 and...... ground char slurry samples with 5e20 wt% solid loading obtain a volumetric energy density of 21e23 GJ/m3. The slurry sample with 20 wt% ground char having a d80 of 118 mm was pumped successfully into a pressurized chamber (0e6 bar) while plugging appeared when the slurry samples with 15 wt% char having a...

  12. Removal of cobalt- and mercury-EDTA chelates from aqueous solutions with a macroporous char

    International Nuclear Information System (INIS)

    A bench-scale method was developed to remove cobalt- and mercury-EDTA chelates from water onto macroporous char. Experimental parameters included variations on solution pH, char pre-treatment, cobalt oxidation state, and apparatus configuration. The use of 60Co and 203Hg radiotracers allowed for total accountability of the metals in the char and effluents. Overall experimental results demonstrate the applicability of treated macroporous chars for the effective removal of both cobalt and mercury EDTA chelates from aqueous solutions. The char system was optimized to sequester 97.5% and 99.8% of the cobalt- and mercury-EDTA from 20 ppm solutions, respectively. (author)

  13. A study on the char burnout characteristics of coal and biomass blends

    Energy Technology Data Exchange (ETDEWEB)

    Behdad Moghtaderi [University of Newcastle, Callaghan, NSW (Australia). Discipline of Chemical Engineering, School of Engineering, Faculty of Engineering and Built Environment

    2007-10-15

    The char burnout characteristics of coal/biomass blends under conditions pertinent to pulverised fuel combustors were investigated by a combined modelling and experimental approach. Results indicate that blending of coal with biomass increases the likelihood of char extinction (i.e. extinction potential of the char particle in the blend), in turn, decreasing the char burnout level. Our modelling results attribute this to a reduction in the char particle size to levels below a critical dimension which appears to be a strong function of the fuel blending ratio (the weight percentage of biomass in the blend), fuel reactivity, char cloud shape and particle density number. It is demonstrated here that the drop in the char burnout level during co-firing can be effectively resolved when a more reactive secondary coal is added to the blend to minimise its extinction potential. 22 refs., 8 figs., 2 tabs.

  14. Structure Based Predictive Model for Coal Char Combustion

    Energy Technology Data Exchange (ETDEWEB)

    Robert Hurt; Joseph Calo; Robert Essenhigh; Christopher Hadad

    2000-12-30

    This unique collaborative project has taken a very fundamental look at the origin of structure, and combustion reactivity of coal chars. It was a combined experimental and theoretical effort involving three universities and collaborators from universities outside the U.S. and from U.S. National Laboratories and contract research companies. The project goal was to improve our understanding of char structure and behavior by examining the fundamental chemistry of its polyaromatic building blocks. The project team investigated the elementary oxidative attack on polyaromatic systems, and coupled with a study of the assembly processes that convert these polyaromatic clusters to mature carbon materials (or chars). We believe that the work done in this project has defined a powerful new science-based approach to the understanding of char behavior. The work on aromatic oxidation pathways made extensive use of computational chemistry, and was led by Professor Christopher Hadad in the Department of Chemistry at Ohio State University. Laboratory experiments on char structure, properties, and combustion reactivity were carried out at both OSU and Brown, led by Principle Investigators Joseph Calo, Robert Essenhigh, and Robert Hurt. Modeling activities were divided into two parts: first unique models of crystal structure development were formulated by the team at Brown (PI'S Hurt and Calo) with input from Boston University and significant collaboration with Dr. Alan Kerstein at Sandia and with Dr. Zhong-Ying chen at SAIC. Secondly, new combustion models were developed and tested, led by Professor Essenhigh at OSU, Dieter Foertsch (a collaborator at the University of Stuttgart), and Professor Hurt at Brown. One product of this work is the CBK8 model of carbon burnout, which has already found practical use in CFD codes and in other numerical models of pulverized fuel combustion processes, such as EPRI's NOxLOI Predictor. The remainder of the report consists of detailed

  15. Production, characterization and reactivity studies of chars produced by the isothermal pyrolysis of flax straw

    International Nuclear Information System (INIS)

    The influence of pyrolysis temperature and residence time on the char yields and resultant char characteristics were investigated in the isothermal pyrolysis of flax straw. The pyrolysis temperature was varied in the range between 300 and 500 °C and reaction residence time was varied from 15 to 60 min. The char yield was found to decrease with both increasing pyrolysis temperature and residence time. The char structure and physical characteristics were thoroughly investigated by means of X-ray diffraction (XRD), temperature-programmed oxidation (TPO) and N2 physisorption techniques. The results show that the degree of porosity and graphitization increased with increasing pyrolysis temperature and time. TPO studies on the char samples corroborate well with the XRD findings and showed the presence of two types of carbon; namely, amorphous filamentous carbon and crystalline graphitic carbon. Thermogravimetric analysis (TGA) of the char was performed to understand the combustion kinetics and reactivity. Chars formed at lower pyrolysis temperatures were found to be more reactive than the chars produced at higher pyrolysis temperatures, and these findings are well supported by the TPO, TGA, N2 physisorption and XRD characterization data. Furthermore, an empirical global kinetic model was devised based on power law and used to estimate the activation energy and other kinetic parameters of both flax straw pyrolysis and char combustion processes. -- Highlights: ► The results show conditions to obtain reactive chars from pyrolysis of flax straw. ► A higher pyrolysis temperature leads to a higher amount of nonreactive chars. ► A longer reaction time leads to a higher amount of nonreactive chars. ► A lower pyrolysis temperature and a shorter residence time lead to reactive chars. ► Pyrolysis temperature has a stronger effect on char reactivity than residence time.

  16. Particle size, porosity and temperature effects on char conversion

    International Nuclear Information System (INIS)

    Highlights: → Effect of particle size, porosity and temperature on char conversion is investigated. → Kinetic parameters have been obtained using a chemically controlled experiment. → Transport equation inside the char particle was solved using finite element method. → Large Damkohler number resulted in steep gasifying agent concentration profiles. → Small Damkohler number resulted in constant gasifying agent concentration profile. -- Abstract: The effect of particle size, porosity and reactor temperature/reaction rate constant on the progress of a char particle conversion has been investigated numerically by solving the transport equation inside a reacting char particle. Numerical simulations have been conducted for three cases that include two extreme cases and one general case. The two extreme cases correspond to a very large Damkohler number (3.2607 x 103) and a very small Damkohler number (0.0042). The third case corresponds to an intermediate value of Damkohler number. For the very large Damkohler number case, concentration profiles of the gasifying agent showed a steep gradient across the particle and the reaction occurred mostly in outer layer of the particle. This behavior corresponds to a diffusion controlled process. For the very small Damkohler number case, gasifying agent concentration was a straight line parallel to the x-axis, with a y-axis value of the surrounding concentration. The reaction occurred homogeneously across the particle and the degree of conversion was only a function in time. This behavior corresponds to a chemically controlled process. The total conversion of the char particle as a function of time has also been calculated for different particle sizes, initial porosity and reaction rate constant. Variation in conversion profiles as a function of time due to variation in initial porosity and reaction rate constant were limited to a certain extent. Very high initial porosity values tend to shift the process towards a

  17. Micro-PIXE studies of char populations in northern Canada

    International Nuclear Information System (INIS)

    Micro-PIXE analysis of trace elements in otoliths has been used as the basis for several projects on char, a fish that is important for aboriginal subsistence fisheries in Arctic Canada. Life-history patterns were originally inferred from micro-PIXE line scans of Sr distribution. These were confirmed by superposition of Sr distribution patterns on optical images of otoliths of tag-recaptured fish. Char from various populations showed differentiation in otolith primordial Sr concentration; this enables us to differentiate biological stocks and, it is hoped, eventually to assign individuals from mixed-stock fisheries to their stock of origin. Zn oscillations also correlate with annular structure and provide additional temporally constrained information on fish habitat and behaviour

  18. Identification of a charred corpse through dental records

    OpenAIRE

    Isamara Geandra Cavalcanti Caputo; Jair Naves dos Reis; Teresa Cristina Pantozzi Silveira; Marco Aurélio Guimarães; Ricardo Henrique Alves da Silva

    2011-01-01

    Introduction: Forensic Dentistry is an area of Dentistry related to Law. Among its goals is the execution of human identification, defined as the process of determining the person’s identity. The forensic dentist uses, in this process, ante-mortem records and data for comparison with post-mortem information obtained from the examination of the body. Objective: To describe the process of identification of a charred corpse by using dental records. Case report: The human material remained from a...

  19. Structure-Based Predictive model for Coal Char Combustion.

    Energy Technology Data Exchange (ETDEWEB)

    Hurt, R.; Colo, J [Brown Univ., Providence, RI (United States). Div. of Engineering; Essenhigh, R.; Hadad, C [Ohio State Univ., Columbus, OH (United States). Dept. of Chemistry; Stanley, E. [Boston Univ., MA (United States). Dept. of Physics

    1997-09-24

    During the third quarter of this project, progress was made on both major technical tasks. Progress was made in the chemistry department at OSU on the calculation of thermodynamic properties for a number of model organic compounds. Modelling work was carried out at Brown to adapt a thermodynamic model of carbonaceous mesophase formation, originally applied to pitch carbonization, to the prediction of coke texture in coal combustion. This latter work makes use of the FG-DVC model of coal pyrolysis developed by Advanced Fuel Research to specify the pool of aromatic clusters that participate in the order/disorder transition. This modelling approach shows promise for the mechanistic prediction of the rank dependence of char structure and will therefore be pursued further. Crystalline ordering phenomena were also observed in a model char prepared from phenol-formaldehyde carbonized at 900{degrees}C and 1300{degrees}C using high-resolution TEM fringe imaging. Dramatic changes occur in the structure between 900 and 1300{degrees}C, making this char a suitable candidate for upcoming in situ work on the hot stage TEM. Work also proceeded on molecular dynamics simulations at Boston University and on equipment modification and testing for the combustion experiments with widely varying flame types at Ohio State.

  20. Influence of pyrolysis conditions on the structure and gasification reactivity of biomass chars

    Energy Technology Data Exchange (ETDEWEB)

    E. Cetin; B. Moghtaderi; R. Gupta; T.F. Wall [University of Newcastle, Callaghan, NSW (Australia). Discipline of Chemical Engineering, Faculty of Engineering and Built Environment, School of Engineering

    2004-11-01

    The physical and chemical structure as well as gasification reactivities of chars generated from several biomass species (i.e. pinus radiata, eucalyptus maculata and sugar cane bagasse) were studied to gain insight into the role of heating rate and pressure on the gasification characteristics of biomass chars. Char samples were generated in a suite of reactors including a wire mesh reactor, a tubular reactor, and a drop tube furnace. Scanning electron microscopy analysis, X-ray diffractometry, digital cinematography and surface area analysis were employed to determine the impact of operating conditions on the char structure. The global gasification reactivities of char samples were also determined for a range of pressures between 1 and 20 bar using pressurised thermogravimetric analysis technique. Char reactivities were found to increase with increasing pyrolysis heating rates and decreasing pyrolysis pressure. It was found that under high heating rates the char particles underwent plastic deformation (i.e. melted) developing a structure different to that of the virgin biomass. Pressure was also found to influence the physical and chemical structures of char particles. The difference in the gasification reactivities of biomass chars at pressure was found to correlate well with the effect of pyrolysis pressure on the graphitisation process in the biomass char structure. 29 refs., 18 figs., 2 tabs.

  1. Modeling and field observations of char bed processes in black liquor recovery boilers

    Energy Technology Data Exchange (ETDEWEB)

    Engblom, M.

    2010-07-01

    The char bed plays an important role in kraft black liquor combustion. Stable operation of the char bed promotes efficient and safe operation of the black liquor recovery boiler. It also plays a crucial role in the recovery of the pulping chemicals. Char bed operation involves controlling the char bed size and shape. Mathematical modeling based on computational fluid dynamics (CFD) haas been applied to recovery boilers for increased insights into the recovery furnace processes and to aid in the design of new boilers. So far, all CED-based char bed models reported in literature have used a fixed bed shape. This imposes restrictions on simulation of char bed burning by not considering inherently occurring changes in bed shape. In this thesis, a CED -based recovery furnace model is further developed to predict changes in bed shape. The new model is used in simulation of existing recovery boilers. The predictions of bed shape are compared with observations from real boilers. The furnace model is capable of correctly simulating the overall response of the char bed size to operational changes. This confirms the current quantitative overall understanding of char bed burning. In addition to modeling, visual observations of the char bed processes were made in this work. The observations provide validation data concerning the physical behavior of the char bed, and the findings from the observations can be used in further development of char bed models. Modeling and simulations of fundamental laboratory scale char bed experiments reported in literature are also carried out. The simulations complement the experimental data by providing detailed insights into gas phase reactions that can occur inside the gas boundary layer above a char bed. (orig.)

  2. The effect of char structure on burnout during pulverized coal combustion at pressure

    Energy Technology Data Exchange (ETDEWEB)

    Liu, G.; Wu, H.; Benfell, K.E.; Lucas, J.A.; Wall, T.F.

    1999-07-01

    An Australian bituminous coal sample was burnt in a drop tube furnace (DTF) at 1 atm and a pressurized drop tube furnace (PDTF) at 15 atm. The char samples were collected at different burnout levels, and a scanning electron microscope was used to examine the structures of chars. A model was developed to predict the burnout of char particles with different structures. The model accounts for combustion of the thin-walled structure of cenospheric char and its fragmentation during burnout. The effect of pressure on reaction rate was also considered in the model. As a result, approximately 40% and 70% cenospheric char particles were observed in the char samples collected after coal pyrolysis in the DTF and PDTF respectively. A large number of fine particles (< 30 mm) were observed in the 1 atm char samples at burnout levels between 30% and 50%, which suggests that significant fragmentation occurred during early combustion. Ash particle size distributions show that a large number of small ash particles formed during burnout at high pressure. The time needed for 70% char burnout at 15 atm is approximately 1.6 times that at 1 atm under the same temperature and gas environment conditions, which is attributed to the different pressures as well as char structures. The overall reaction rate for cenospheric char was predicted to be approximately 2 times that of the dense chars, which is consistent with previous experimental results. The predicted char burnout including char structures agrees reasonably well with the experimental measurements that were obtained at 1 atm and 15 atm pressures.

  3. Comparison of char structural characteristics and reactivity during conventional air and oxy-fuel combustion

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Xiaowei; Xu, Minghou; Yao, Hong; Gu, Ying; Si, Junping; Xiong, Chao [Huazhong Univ. of Science and Technology, Wuhan (China). State Key Lab. of Coal Combustion

    2013-07-01

    The capture and sequestration of CO{sub 2} generated from large- scale stationary power plants is considered to be one of the leading technologies that could potentially have a significant impact on reducing greenhouse emissions. Among these emerging technologies, the oxy-fuel combustion is a near-zero emission technology that can be adapted to both new and existing pulverized coal-fired power stations. The goal of this work is to make a comparative study on char structural characteristics (including char yield, swelling ratio, BET surface area, pore distribution, morphology) and reactivity during conventional air and oxy-fuel combustion. Specific experimental designs include two series. One is carried out in pure N{sub 2} and CO{sub 2} (pyrolysis experiments), and another is prepared in N{sub 2} + 5%O{sub 2} and CO{sub 2} + 5%O{sub 2}. Coal samples included raw coal, low density fraction coal and medium density fraction coal in all experiments. The present study is a further effort to extend our knowledge about physical and chemical structural characteristics and reactivity of char in the presence of high concentration CO{sub 2}. Combustion and pyrolysis of a density fractionated China coal at drop tube furnace yielded the following conclusions. Compared to oxy-chars obtained under pure CO{sub 2} atmosphere, the swelling ratios of char obtained in pure N{sub 2} atmosphere are higher. When adding 5%O{sub 2}, experimental results are completely different with those of the pyrolysis experiment. In comparison with the oxy-chars obtained under CO{sub 2} + 5%O{sub 2} atmosphere, the swelling ratios of the char obtained in N{sub 2} + 5%O{sub 2} atmosphere are lower. In the pyrolysis experiment, the BET surfaces Area of the oxy-chars are about 10-20 times as much as chars. When adding 5%O{sub 2}, the BET surfaces Area of the oxy-chars are about two to four times as much as chars. During pyrolysis experiment, the total pore volumes of the oxy-chars obtained under pure CO

  4. Thermal decomposition and gasification of biomass pyrolysis gases using a hot bed of waste derived pyrolysis char.

    Science.gov (United States)

    Al-Rahbi, Amal S; Onwudili, Jude A; Williams, Paul T

    2016-03-01

    Chars produced from the pyrolysis of different waste materials have been investigated in terms of their use as a catalyst for the catalytic cracking of biomass pyrolysis gases during the two-stage pyrolysis-gasification of biomass. The chars were produced from the pyrolysis of waste tyres, refused derived fuel and biomass in the form of date stones. The results showed that the hydrocarbon tar yields decreased significantly with all the char materials used in comparison to the non-char catalytic experiments. For example, at a cracking temperature of 800°C, the total product hydrocarbon tar yield decreased by 70% with tyre char, 50% with RDF char and 9% with biomass date stones char compared to that without char. There was a consequent increase in total gas yield. Analysis of the tar composition showed that the content of phenolic compounds decreased and polycyclic aromatic hydrocarbons increased in the product tar at higher char temperatures. PMID:26773946

  5. Thermochemistry and kinetics of oxygen interaction with microporous chars. Technical report 12. [199 references

    Energy Technology Data Exchange (ETDEWEB)

    Ismail, I M.K.; Walker, P L

    1979-01-01

    In processes involving the hydrogasification of coal, the coal is first exposed to hydrogen at elevated temperatures and pressures during which devolatilization and gasification of the more reactive parts of the coal occur. A microporous coal char, which is relatively unreactive, is also produced. The char, in turn, can be reacted with steam to generate the hydrogen needed in the first part of the process. Or the char, in part, can be used in a boiler to raise steam. In any case, characterization of coal chars and the relation of character to behavior during gasification and/or combustion is important. This report is primarily concerned with laying the experimental base for the measurement of the heat of interaction of a gas (oxygen in this case) with chars. Following the laying of this base, using a char produced from a reproducible polymer system, heats of interaction of oxygen with chars produced from American coals, ranging in rank from anthracite to lignite, were measured. Differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA) were used to study the exothermicity and kinetics of interaction between Saran chars and oxygen at selected isothermal temperatures in the range 75 to 850/sup 0/C. The combination of measuring heats of oxygen interaction with chars (using the DSC technique) and weight changes during the interaction opens up a valuable new technique to characterize coal chars. Heats of interaction at 100/sup 0/C are found to be related to rates of char gasification at higher temperatures. Both heats of interaction and gasification rates are, in turn, seen to increase sharply as the rank of coal from which the char is produced is decreased.

  6. Activated carbon from char obtained from vacuum pyrolysis of teak sawdust: pore structure development and characterization.

    Science.gov (United States)

    Ismadji, S; Sudaryanto, Y; Hartono, S B; Setiawan, L E K; Ayucitra, A

    2005-08-01

    The preparation of activated carbon from vacuum pyrolysis char of teak sawdust was studied and the results are presented in this paper. The effects of process variables such as temperature and activation time on the pore structure of activated carbons were studied. The activated carbon prepared from char obtained by vacuum pyrolysis has higher surface area and pore volume than that from atmospheric pyrolysis char. The BET surface area and pore volume of activated carbon prepared from vacuum pyrolysis char were 1150 m2/g and 0.43 cm3/g, respectively. PMID:15792584

  7. Suspension Combustion of Wood: Influence of Pyrolysis Conditions on Char Yield, Morphology, and Reactivity

    DEFF Research Database (Denmark)

    Dall'Ora, Michelangelo; Jensen, Peter Arendt; Jensen, Anker Degn

    2008-01-01

    Chars from pine and beech wood were produced by fast pyrolysis in an entrained flow reactor and by slow pyrolysis in a thermogravimetric analyzer. The influence of pyrolysis temperature, heating rate and particle size on char yield and morphology was investigated. The applied pyrolysis temperatur......, char oxidation reactivity decreased as pyrolysis temperature increased. The amount and composition of the ash forming matter of the wood fuels seems to play an important role in determining the differences in char yield, morphology and reactivity.......Chars from pine and beech wood were produced by fast pyrolysis in an entrained flow reactor and by slow pyrolysis in a thermogravimetric analyzer. The influence of pyrolysis temperature, heating rate and particle size on char yield and morphology was investigated. The applied pyrolysis temperature...... varied in the range 673−1673 K for slow pyrolysis and between 873 and 1573 K for fast pyrolysis. The chars were oxidized in a thermogravimetric analyzer and the mass loss data were used to determine char oxidation reactivity. Char yield from fast pyrolysis (104−105 K/s) was as low as 1 to 6% on a dry ash...

  8. Study of the reaction of uranium and plutonium with bone char

    International Nuclear Information System (INIS)

    A study of the reaction of plutonium with a commercial bone char indicates that this bone char has a high capacity for removing plutonium from aqueous wastes. The adsorption of plutonium by bone char is pH dependent, and for plutonium(IV) polymer appears to be maximized near pH 7.3 for plutonium concentrations typical of some waste streams. Adsorption is affected by dissolved salts, especially calcium and phosphate salts. Freundlich isotherms representing the adsorption of uranium and plutonium have been prepared. The low potential imposed upon aqueous solutions by commercial bone char is adequate for reduction of hexavalent plutonium to a lower plutonium oxidation state

  9. Effect of pyrolysis pressure and heating rate on radiata pine char structure and apparent gasification reactivity

    Energy Technology Data Exchange (ETDEWEB)

    E. Cetin; R. Gupta; B. Moghtaderi [University of Newcastle, Callaghan, NSW (Australia). Discipline of Chemical Engineering, Faculty of Engineering and Built Environment, School of Engineering

    2005-07-01

    The knowledge of biomass char gasification kinetics has considerable importance in the design of advanced biomass gasifiers, some of which operate at high pressure. The char gasification kinetics themselves are influenced by char structure. In this study, the effects of pyrolysis pressure and heating rate on the char structure were investigated using scanning electron microscopy (SEM) analysis, digital cinematography, and surface area analysis. Char samples were prepared at pressures between 1 and 20 bar, temperatures ranging from 800 to 1000{degree}C, and heating rates between 20 and 500{degree}C/s. Our results indicate that pyrolysis conditions have a notable impact on the biomass char morphology. Pyrolysis pressure, in particular, was found to influence the size and the shape of char particles while high heating rates led to plastic deformation of particles (i.e. melting) resulting in smooth surfaces and large cavities. The global gasification reactivities of char samples were also determined using thermogravimetric analysis (TGA) technique. Char reactivities were found to increase with increasing pyrolysis heating rates and decreasing pyrolysis pressure. 22 refs., 8 figs., 2 tabs.

  10. Adsorption of copper onto char derived macro alga, Undaria pinnatifida

    International Nuclear Information System (INIS)

    Full text: A release of heavy metals into the environment by industrial activities raises much environmental problems because they tend to remain indefinitely, circulating and eventually accumulating throughout the food chain. Copper is essential to human life and health but, like all heavy metals, is potentially toxic as well. The excessive intakes of copper result in its accumulation in the liver and produce gastrointestinal problems, kidney damage, anemia, and continued inhalation of copper-containing sprays is linked with an increase in lung cancer among exposed people. Consequently, we need to eliminate the copper in drinking water. Also, growth rates of marine macro algae far exceed those of terrestrial biomass, without water limitations, so annual primary production rates are higher for the major marine macro algae than for most terrestrial biomass. According to these reasons, we try to use the macro alga, Undaria pinnatifida. Adsorption of heavy metals is one of the possible technologies involved in the removal of toxic metals from industrial waste streams and mining waste water using low-cost adsorbents. In recent years, many low-cost adsorbents such as seaweeds, activated carbon, etc. have been investigated, but the char by macro alga, Undaria pinnatifida, have not proven to be the most effective and promising substrates. The aim of this study is to remove copper from its aqueous solution by Undaria pinnatifida char for various parameters like pH, contact time, and Cu(II) concentration. The adsorption capacity of Cu(II) by Undaria pinnatifida char was investigated as a function of pH, contact time, and Cu(II) concentration at room temperature. And it was verified using equilibrium studies. (author)

  11. Particle behavior and char burnout mechanisms under pressurized combustion conditions

    Energy Technology Data Exchange (ETDEWEB)

    Bauer, C.M.; Spliethoff, H.; Hein, K.R.G.

    1999-07-01

    Combined cycle systems with coal-fired gas turbines promise highest cycle efficiencies for this fuel. Pressurized pulverized coal combustion, in particular, yields high cycle efficiencies due to the high flue gas temperatures possible. The main problem, however, is to ensure a flue gas clean enough to meet the high gas turbine standards with a dirty fuel like coal. On the one hand, a profound knowledge of the basic chemical and physical processes during fuel conversion under elevated pressures is required whereas on the other hand suitable hot gas cleaning systems need to be developed. The objective of this work was to provide experimental data to enable a detailed description of pressurized coal combustion processes. A series of experiments were performed with two German hvb coals, Ensdorf and Goettelborn, and one German brown coal, Garzweiler, using a semi-technical scale pressurized entrained flow reactor. The parameters varied in the experiments were pressure, gas temperature and bulk gas oxygen concentration. A two-color pyrometer was used for in-situ determination of particle surface temperatures and particle sizes. Flue gas composition was measured and solid residue samples taken and subsequently analyzed. The char burnout reaction rates were determinated varying the parameters pressure, gas temperature and initial oxygen concentration. Variation of residence time was achieved by taking the samples at different points along the reaction zone. The most influential parameters on char burnout reaction rates were found to be oxygen partial pressure and fuel volatile content. With increasing pressure the burn-out reactions are accelerated and are mostly controlled by product desorption and pore diffusion being the limiting processes. The char burnout process is enhanced by a higher fuel volatile content.

  12. Production and characterization of Lemna minor bio-char and its catalytic application for biogas reforming

    International Nuclear Information System (INIS)

    Pyrolysis of fast-growing aquatic biomass - Lemna minor (commonly known as duckweed) with the emphasis on production, characterization and catalytic application of bio-char is reported in this paper. The yield of bio-char was determined as a function of L. minor pyrolysis temperature and sweep gas flow rate. It was found that the pore development during L. minor pyrolysis was not significant and the changes in the reaction conditions (temperature and sweep gas flow rate) did not alter markedly the textural characteristics and BET surface area of the bio-char produced. Thermogravimetric/differential thermogravimetric (TG/DTG) analyses of L. minor and different bio-char samples in inert (helium) and oxidative (air) media showed substantial differences in their TG/DTG patterns. A comparison of scanning electron micrographs (SEM) of L. minor, bio-char and ash indicated that the basic structural features of L. minor remained intact and were not affected by thermolysis. The inorganic ash content of L. minor derived bio-char is significantly higher than that of typical terrestrial (plant) biomass. The energy dispersive spectroscopic (EDS) analysis of L. minor ash showed that it mostly consisted of silica, and small quantities of Na, K and Ca compounds. The treatment of bio-char with CO2 at 800 °C increased its BET surface area. It was found that CO2-treated bio-char exhibited appreciable initial catalytic activity in biogas reforming. -- Highlights: New data on characterization of bio-chars derived from Lemna minor are presented. ► Effect of pyrolysis operational parameters on bio-char properties is determined. ► Basic skeletal structure of Lemna minor leaflets does not change during pyrolysis. ► Bio-chars show an appreciable initial catalytic activity for biogas reforming.

  13. Preparation of porous bio-char and activated carbon from rice husk by leaching ash and chemical activation.

    Science.gov (United States)

    Ahiduzzaman, Md; Sadrul Islam, A K M

    2016-01-01

    Preparation porous bio-char and activated carbon from rice husk char study has been conducted in this study. Rice husk char contains high amount silica that retards the porousness of bio-char. Porousness of rice husk char could be enhanced by removing the silica from char and applying heat at high temperature. Furthermore, the char is activated by using chemical activation under high temperature. In this study no inert media is used. The study is conducted at low oxygen environment by applying biomass for consuming oxygen inside reactor and double crucible method (one crucible inside another) is applied to prevent intrusion of oxygen into the char. The study results shows that porous carbon is prepared successfully without using any inert media. The adsorption capacity of material increased due to removal of silica and due to the activation with zinc chloride compared to using raw rice husk char. The surface area of porous carbon and activated carbon are found to be 28, 331 and 645 m(2) g(-1) for raw rice husk char, silica removed rice husk char and zinc chloride activated rice husk char, respectively. It is concluded from this study that porous bio-char and activated carbon could be prepared in normal environmental conditions instead of inert media. This study shows a method and possibility of activated carbon from agro-waste, and it could be scaled up for commercial production. PMID:27536531

  14. Simulation of coal char gasification using O2/CO2

    Institute of Scientific and Technical Information of China (English)

    Haibin Li; Yu Yu; Minfang Han; Ze Lei

    2014-01-01

    The authors proposed an integrated gasification fuel cell zero-emission system. The coal char gasification is discussed using high temperature and concentration of CO2 produced by solid oxide fuel cells and oxy-fuel combustion. The gasification is simulated by Aspen plus based on Gibbs free energy minimization method. Gasification model of pulverized coal char is computed and analyzed. Effects of gas flow rate, pressure, preheating temperature, heat losses on syngas composition, reaction temperature, lower heating value and carbon conversion are studied. Results and parameters are determined as following. The optimum O2 flow rate is 20 kg/h. The reaction temperature decreases from 1645 to 1329 ?C when the CO2 flow rate increases from 0 to 5 kg/h, the CO2 flow rate should be operated reasonably; lower heating value reduces and reaction temperature increases as the pressure increases;compared to the CO2 preheating, O2 preheating has greater influence on reaction temperature and lower heating value.

  15. Bone char quality and defluoridation capacity in contact precipitation

    DEFF Research Database (Denmark)

    Albertus, J.; Bregnhøj, Henrik; Kongpun, M.

    2002-01-01

    Samples from six different brands of bone char are tested for their capacity to remove fluoride from water in batch. Initial concentrations of 10 mg/L and contact times of 6 hours are used. The removal capacities observed are 0.6-1.1 mg/g on an average, s.d. being 0.16. Addition of calcium and...... are added as in the contact precipitation process. The results show that the columns are able to remove up to 700 bedvolumes, before the concentration of fluoride in the effluent water breaks through, above 1.5 mg/L. Operational removal capacities observed are 7 and 9 mg/L, depending on contact time...... phosphate compounds to the jar experiments results in more than doubling of these capacities, on average 1.9 mg/g, s.d. being 0.14. One of bone char products is setup in columns are fed with water, 100 mg/L, for saturation. Hereafter the coloumns are fed with water of 10 mgF/L where calcium and phosphate...

  16. Bio-char derived from sewage sludge by liquefaction: Characterization and application for dye adsorption

    Energy Technology Data Exchange (ETDEWEB)

    Leng, Lijian [College of Environmental Science and Engineering, Hunan University, Changsha 410082 (China); Key Laboratory of Environment Biology and Pollution Control, Hunan University, Ministry of Education, Changsha 410082 (China); Yuan, Xingzhong, E-mail: yxz@hnu.edu.cn [College of Environmental Science and Engineering, Hunan University, Changsha 410082 (China); Key Laboratory of Environment Biology and Pollution Control, Hunan University, Ministry of Education, Changsha 410082 (China); Huang, Huajun [School of Land Resources and Environment, Jiangxi Agricultural University, Nanchang 330045 (China); Shao, Jianguang; Wang, Hou [College of Environmental Science and Engineering, Hunan University, Changsha 410082 (China); Key Laboratory of Environment Biology and Pollution Control, Hunan University, Ministry of Education, Changsha 410082 (China); Chen, Xiaohong [School of Business, Central South University, Changsha 410083 (China); Zeng, Guangming [College of Environmental Science and Engineering, Hunan University, Changsha 410082 (China); Key Laboratory of Environment Biology and Pollution Control, Hunan University, Ministry of Education, Changsha 410082 (China)

    2015-08-15

    Graphical abstract: - Highlights: • SS liquefaction bio-chars were effective on MG and MB removal from aqueous. • MG adsorption capacity depended strongly on carboxylic and phenolic groups. • Metal release accounted for nearly 30% of the total MG adsorbed on bio-chars. • Acetone and low temperature favor effective adsorbent production by liquefaction. - Abstract: Bio-chars produced by liquefaction of sewage sludge with methanol, ethanol, or acetone as the solvent at 260–380 °C were characterized in terms of their elemental composition, thermogravimetric characteristics, surface area and pore size distribution, and oxygen-containing functional groups composition. The surface area and total volume of the bio-chars were low, but the contents of oxygen-containing functional groups were high. The bio-chars were effective on Malachite green (MG) and Methylene blue (MB) removal from aqueous solution. The MG adsorption equilibrium data showed excellent fit to the Langmuir model and the kinetic data fitted well to the Pseudo-second-order model. Thermodynamic investigations indicated that MG adsorption on bio-char was spontaneous and endothermic. The MG adsorption mechanism appears to be associated with cation release and functional group participation. Additionally, liquefaction of SS with acetone as the solvent at low temperature (280 °C) would favor the production of bio-char adsorbent in terms of bio-char yield and MG and MB adsorption capacity.

  17. Investigation of the Anisotropic Behavior of Wood Char Particles during Gasification

    DEFF Research Database (Denmark)

    Henriksen, Ulrik Birk; Hindsgaul, Claus; Qvale, Einar Bjørn;

    2006-01-01

    during gasification of wood using macro TGA equipment. The char particles, in the form of slabs (approximately 50 × 70 × 10 mm), were produced by pyrolysis of wood slabs that had been cut from the trunk of beech trees. The char slabs were grouped into three categories according to the orientation of the...

  18. Electron paramagnetic resonance and dynamic nuclear polarization of char suspensions: surface science and oximetry

    DEFF Research Database (Denmark)

    Clarkson, R B; Odintsov, B M; Ceroke, P J;

    1998-01-01

    ; they can be calibrated and used for oximetry. Biological stability and low toxicity make chars good sensors for in vivo measurements. Scalar and dipolar interactions of water protons at the surfaces of chars may be utilized to produce dynamic nuclear polarization (DNP) of the nuclear spin population...

  19. Physico-Chemical Characterizations of Sawdust-Derived Bio char as Potential Solid Fuels

    International Nuclear Information System (INIS)

    Characterization Malaysian rubber-wood sawdust derived bio char (MRWSB) produced in the fixed bed pyrolysis under different temperatures (450 to 850 degree Celsius) were studied for its applicability as a solid fuel. A range of analyses were carried out, including bio char oxidation reactivity , inorganic species, oxygen and hydrogen contents in the bio chars, release of heteroatoms in bio char as the gaseous product, and bio char structural evolution during pyrolysis process. The results show that the optimum temperature for carbonization to obtain a char having moderately high yield was found as 450 degree Celsius. Thermogravimetric analyses (TG) shows that temperatures induces a progressively more ordered carbonaceous structure and leads to a significant changes in the bio char reactivity. The process is coupled with the loss of heteroatoms, released as dominantly carbon dioxide (C02) and carbon dioxide (CO). In addition, the elemental study of wood-derived bio char shows the higher carbon content but with low H/C and 0/C ratio suggested this material was dominated by highly aromatic structures and this were revealed in the Fourier transform infra-red (FTIR). More importantly, insignificant amount of inorganic species is evidenced in the samples. (author)

  20. Production and Characterization of Bio-Char from the Pyrolysis of Empty Fruit Bunches

    Directory of Open Access Journals (Sweden)

    Mohamad A. Sukiran

    2011-01-01

    Full Text Available Problem statement: The palm oil industry generates an abundance of oil palm biomass such as the Empty Fruit Bunch (EFB, shell, frond, trunk and Palm Oil Mill Effluent (POME. For 88 million tones of Fresh Fruit Bunch (FFB processed in 2008, the amount of oil palm biomass was more than 26 million tones. Studies about production of bio-char from oil palm biomass are still lacking in Malaysia. So, this study was aimed to: (i determine the effect of pyrolysis temperatures on bio-char yield (ii characterize the bio-char obtained under different pyrolysed temperatures. Approach: In this study, pyrolysis of EFB was conducted using a fluidized fixed bed reactor. The effect of pyrolysis temperatures on bio-char yield was investigated. The pyrolysis temperature used ranged from 300-700°C. The elemental analysis, calorific value, surface area and total pore volume of the bio-char were determined. Results: The highest bio char yield of 41.56% was obtained at an optimum pyrolysis temperature of 300°C with particle size of 91-106 μm and the heating rate of 30°C min-1. The calorific values of bio-char ranged from 23-26 MJ kg-1. Conclusion: It was found that the bio-char products can be characterized as carbon rich, high calorific value and potential solid biofuels.

  1. Bio-char derived from sewage sludge by liquefaction: Characterization and application for dye adsorption

    International Nuclear Information System (INIS)

    Graphical abstract: - Highlights: • SS liquefaction bio-chars were effective on MG and MB removal from aqueous. • MG adsorption capacity depended strongly on carboxylic and phenolic groups. • Metal release accounted for nearly 30% of the total MG adsorbed on bio-chars. • Acetone and low temperature favor effective adsorbent production by liquefaction. - Abstract: Bio-chars produced by liquefaction of sewage sludge with methanol, ethanol, or acetone as the solvent at 260–380 °C were characterized in terms of their elemental composition, thermogravimetric characteristics, surface area and pore size distribution, and oxygen-containing functional groups composition. The surface area and total volume of the bio-chars were low, but the contents of oxygen-containing functional groups were high. The bio-chars were effective on Malachite green (MG) and Methylene blue (MB) removal from aqueous solution. The MG adsorption equilibrium data showed excellent fit to the Langmuir model and the kinetic data fitted well to the Pseudo-second-order model. Thermodynamic investigations indicated that MG adsorption on bio-char was spontaneous and endothermic. The MG adsorption mechanism appears to be associated with cation release and functional group participation. Additionally, liquefaction of SS with acetone as the solvent at low temperature (280 °C) would favor the production of bio-char adsorbent in terms of bio-char yield and MG and MB adsorption capacity

  2. Thermogravimetric Analysis of Char Waste from the Air Gasification of Empty Fruit Bunch Briquette.

    Directory of Open Access Journals (Sweden)

    Nyakuma Bemgba Bevan

    2014-07-01

    Full Text Available The thermal decomposition behavior of char waste produced from the air gasification of Empty Fruit Bunch (EFB briquette was examined using thermogravimetric analysis (TGA. A comparison between the thermal decomposition behavior of char waste and EFB briquette is also presented. The results indicate that the char waste produced decreased from 22 % to 18 % with increasing temperature from 600 °C to 700 °C during gasification. This is due to the effect of high temperatures on the primary char decomposition reactions. It was observed that char degradation occurs in two steps; char degradation I & II with weight losses of 17 % and 32 % respectively. This showed that only ~ 50 % char was decomposed during thermal analysis, hence higher temperatures are required to ensure complete decomposition. The TGA curve for EFB briquette showed that complete thermal decomposition of EFB briquette occurs in four stages namely; drying, devolatization, reduction and char degradation. The most significant weight loss 2.51 mg or 49.31 % occurred during devolatization.

  3. Combustion kinetics of char from pyrolysis of coal with coke oven gas (COG). Distribution to combustion apparent activation energy of char

    Energy Technology Data Exchange (ETDEWEB)

    Liao, H.; Sun, C.; Li, B. [Chinese Academy of Sciences, Taiyuan(China). Institute of Coal Chemistry

    1999-06-01

    Combustion kinetics of chars from pyrolysis of lignite with COG was studied in detail. The combustion kinetics model of char was set by the equation -dX/dt=6K(1-X){sup 0.66}P{sub O{sub 2}}{sup 0.5}/{rho}{sub O}d{sub O}. A new method was suggested to describe the distribution of apparent energy during the combustion of char. It was found that the apparent activation energy shows the similar but reverse shape with combustion rate plot during the combustion of char and spreads over 47-95 kJ/mol. The lowest apparent activation energy was found in the combustion conversion (f) of about 40w% (daf). In the combustion of the same char, there is a definite correlation between combustion rate and apparent activation energy, i.e., high burning rate is related to low apparent activation energy. Thus, apparent activation energy can be used to describe the combustion reactivity of char. 9 refs., 4 figs., 1 tab.

  4. Analysis of the fluidized bed combustion behavior of Quercus ilex char

    International Nuclear Information System (INIS)

    Because of the high content of alkaline metals, biomass has very reactive ashes and these have a strong impact upon pyrolysis and combustion phenomena. From the study of the evolution with the combustion temperature, of the kinetic and diffusive data of several wood chars, it was found that the Quercus ilex (holm oak) char had an unexpected evolution of the heterogeneous phase reaction rate constant. Scanning electronic microscopy analysis of the ashes and thermogravimetric analysis of the char where performed, and the results shown that close to 750 °C there is a loss of mass associated with the release of inorganic matter, especially potassium and phosphorus, which have a known influence on the combustion process and the subsequent kinetic data collection. - Highlights: • Fluidized bed combustion of biomass. • Combustion behavior of holm oak char. • Influence of alkaline components on char combustion kinetic data

  5. Fast pyrolysis char - Assessment of alternative uses within the bioliq® concept.

    Science.gov (United States)

    Funke, A; Niebel, A; Richter, D; Abbas, M M; Müller, A-K; Radloff, S; Paneru, M; Maier, J; Dahmen, N; Sauer, J

    2016-01-01

    Experiments with a process development unit for fast pyrolysis of biomass residues of 10kgh(-1) have been performed to quantify the impact of two different product recovery options. Wheat straw, miscanthus and scrap wood have been used as feedstock. A separate recovery of char increases the organic oil yield as compared to a combined recovery of char and organic condensate (OC). Furthermore, it allows for an alternative use of the byproduct char which represents an important product fraction for the high ash biomass residues under consideration. The char produced shows little advantage over its biomass precursor when considered as energy carrier due to its high ash content. Significant value can be added by demineralizing and activating the char. The potential to increase the economic feasibility of fast pyrolysis is shown by an assessment of the bioliq® process chain. PMID:26609947

  6. Oxy-fuel combustion of millimeter-sized coal char: Particle temperatures and NO formation

    DEFF Research Database (Denmark)

    Brix, Jacob; Navascués, Leyre Gómez; Nielsen, Joachim Bachmann;

    2013-01-01

    In this work, differences in particle temperature and NO yield during char oxidation in O2/N2 and O2/CO2 atmospheres, respectively, have been examined. A laboratory scale fixed bed reactor, operated isothermally at 1073 K, was used for combustion of millimeter-sized lignite and bituminous coal char...... increased with mass loading, by as much as 700 K above the furnace set point. The formation of NO from lignite char was not influenced by the change from N2 to CO2 whereas the NO yield from bituminous coal char was considerably lower in O2/CO2 compared O2/N2. For both chars the conversion to NO decreased as...

  7. Investigating the morphology and reactivity of chars from Triplochiton scleroxylon pyrolysed under varied conditions.

    Science.gov (United States)

    Oluoti, Kehinde; Pettersson, Anita; Richards, Tobias

    2016-05-01

    A gasifier may be optimised via a good understanding of the char formation, morphology and reactivity. The effects of varying the pyrolysis pressure and heating rate on the morphology of the char were investigated using a thermogravimetric analyser (TGA), scanning electron microscope (SEM) and micrograph spot analyser. The gasified chars were produced at heating rates of 5, 10 and 20°C/min and pressures of 0.1, 0.4 and 0.6 MPa. All the chars have different degrees of apparent gasification reactivity. The random pore model (RPM) provided a better description of the experiment, with low average error values, θ, in all of the cases considered. The alkaline and alkaline earth metals (AAEM) in the tropical wood biomass Arere (Triplochiton scleroxylon) consist predominantly of calcium and could altogether be partly responsible for the noticeably high reactivity nature of the tropical Arere chars. PMID:26926201

  8. Structural evolution of biomass char and its effect on the gasification rate

    DEFF Research Database (Denmark)

    Fatehi, Hesameddin; Bai, Xue Song

    2016-01-01

    The evolution of char porous structure can affect the conversion rate of the char by affecting the intra-particle transport, especially in the zone II conversion regime. A multi-pore model based on the capillary pore theory is developed to take into account different conversion rates for pores with...... different radii. The model is valid for biomass chars produced under relatively low heating rates, when the original beehive structure of the biomass is not destroyed during the pyrolysis stage. The contribution of different pores with different radius is taken into account using an effectiveness factor...... presented for each pore radius with respect to different reactions. As the char conversion proceeds, the pore enlargement increases the contribution of micro-pores; consequently the effective surface area will increase. The increase in the effective surface area leads to an increased reactivity of char...

  9. Investigation of char strength and expansion properties of an intumescent coating exposed to rapid heating rates

    DEFF Research Database (Denmark)

    Nørgaard, Kristian Petersen; Dam-Johansen, Kim; Català, Pere;

    2013-01-01

    addition, char properties, measured at room temperature, were dependent on the preceding storage conditions (in air or in a desiccator). The char was found to have the highest mechanical strength against compression in the outer crust facing the heat source. For thin (147μm) free coating films, a tendency......An efficient and space saving method for passive fire protection is the use of intumescent coatings, which swell when exposed to heat, forming an insulating char layer on top of the virgin coating. Although the temperature curves related to so-called cellulosic fires are often referred to as slow...... heating curves, special cases where the protective char is mechanically damaged and partly removed can cause extremely fast heating of the coating. This situation, for a solvent based intumescent coating, is simulated using direct insertion of free films into a muffle oven. The char formed is evaluated...

  10. Char refiring under O2/N2 and O2/CO2 atmospheres. Implication for PCI injection in blast furnace

    OpenAIRE

    Álvarez Rodríguez, Diego; Casal Banciella, M.ª Dolores; Gómez Borrego, Ángeles; Osório, Eduardo; Vilela, Antonio C. F.

    2007-01-01

    It is attempt in pulverized coal injection (PCI) in blast furnace tuyeres to increase the injection rate without increasing the amount of unburned char inside the stack of the blast furnace. The unburned char can cause problems in the blast furnace operation, such as reduced permeability, undesirable gas/temperature distribution, excessive coke erosion and significant char carryover. In the near tuyere region the coal is injected with air but the resolidified char will burn in an atmosphere w...

  11. Structural features and gasification reactivity of coal chars formed in Ar and CO2 atmospheres at elevated pressures

    International Nuclear Information System (INIS)

    The structural features and gasification reactivity of chars derived from pyrolysis of a bituminous coal under Ar (Ar char) and CO2 atmosphere (CO2 char) have been investigated, respectively. The pyrolysis was performed in a fixed bed reactor at a final temperature of 700 °C and pressures ranging from 0.1 to 1.5 MPa. It was found that CO2 affect the char yield, pore structure and surface area. The N2 surface area of the CO2 char at ambient pressure increased by nearly 42 times compared to the Ar char. The chemical structure features were characterized by using Raman spectroscopy. The recorded spectra between 800 and 1800 cm−1 were curve-fitted with 10 Gaussian bands representing typical structural features of chars to quantitatively compare the char structure difference. The ratio I(Gr+Vl+Vr)/ID between the band intensities of amorphous char structures with small aromatic ring (3–5 rings) systems and condensed aromatic ring systems (>6 rings) is seen to decrease with increasing pyrolysis pressure. The I(Gr+Vl+Vr)/ID of CO2 char is always lower than that of Ar char in the whole pressure range. The non-isothermal CO2 gasification from 700 to 1000 °C in a TGA (thermogravimetric analyzer) indicates that the char prepared under Ar atmosphere was more reactive. - Highlights: • Pressurized coal pyrolysis experiments were run in fixed bed reactor using CO2 or Ar. • Small to large aromatic ring ratio for CO2 chars is always lower than for Ar chars. • Ar derived chars show a slightly enhanced reactivity over CO2 derived chars

  12. Chars produced by slow pyrolysis and hydrothermal carbonization vary in carbon sequestration potential and greenhouse gases emissions

    OpenAIRE

    Malghani, S; G. Gleixner; Trumbore, SE, Reichstein, M.

    2013-01-01

    Bio-char, biomass that has been deliberately charred to slow its rate of decomposition, has been proposed as an amendment with the potential to sequester carbon and improve certain soil properties. Slow pyrolysis (temperature ≤500°C) and hydrothermal carbonization (low temperature, high pressure) are two efficient methods to produce bio-char with high yield and are applicable to a broad range of feedstocks. Chars made using slow pyrolysis (PC) and hydrothermal carbonization (HTC) of the same ...

  13. Prehistoric cereal foods from Greece and Bulgaria: investigation of starch microstructure in experimental and archaeological charred remains

    OpenAIRE

    Valamoti, Soultana-Maria; Samuel, Delwen; Bayram, Mustafa; Elena MARINOVA

    2008-01-01

    Abstract In order to investigate ancient cereal cooking practices, the microstructure of preserved starch in charred ground cereal remains recovered from prehistoric sites in Greece and Bulgaria has been analysed. A comparative modern set of cooked and subsequently charred cereals was produced. By scanning electron microscopy it is demonstrated that, under some conditions, distinctive cooked starch structure survives the charring process. Charring alone can occasionall...

  14. Characterisation and reaction kinetics of high ash chars derived from inertinite-rich coal discards / Rufaro Kaitano

    OpenAIRE

    Kaitano, Rufaro

    2007-01-01

    An investigation was undertaken to determine the gasification and combustion characteristics of chars derived from an inertinite-rich coal discard sample with a high ash content. Fundamental knowledge of the reaction rate kinetics for char conversion at reactions conditions used in fluidised bed gasification and combustion was obtained. For this purpose, characterisation of the parent coal and derived chars, reactivity determinations of the chars and detailed reaction rate mode...

  15. Coal pyrolysis and char burnout under conventional and oxy-fuel conditions

    Energy Technology Data Exchange (ETDEWEB)

    Al-Makhadmeh, L.; Maier, J.; Scheffknecht, G. [Stuttgart Univ. (Germany). Institut fuer Verfahrenstechnik und Dampfkesselwesen

    2009-07-01

    Coal utilization processes such as combustion or gasification generally involve several steps i.e., the devolatilization of organic materials, homogeneous reactions of volatile matter with the reactant gases, and heterogeneous reactions of the solid (char) with the reactant gases. Most of the reported work about coal pyrolysis and char burnout were performed at low temperatures under environmental conditions related to the air firing process with single particle tests. In this work, coal combustion under oxy-fuel conditions is investigated by studying coal pyrolysis and char combustion separately in practical scales, with the emphasis on improving the understanding of the effect of a CO{sub 2}-rich gas environment on coal pyrolysis and char burnout. Two coals, Klein Kopje a medium volatile bituminous coal and a low-rank coal, Lausitz coal were used. Coal pyrolysis in CO{sub 2} and N{sub 2} environments were performed for both coals at different temperatures in an entrained flow reactor. Overall mass release, pyrolysis gas concentrations, and char characterization were performed. For char characterization ultimate analysis, particle size, and BET surface area were measured. Chars for both coals were collected at 1150 C in both CO{sub 2} and N{sub 2} environments. Char combustion was performed in a once-through 20 kW test facility in O{sub 2}/CO{sub 2} and O{sub 2}/N{sub 2} atmospheres. Besides coal quality, oxygen partial pressure was chosen as a variable to study the effect of the gas environment on char burnout. In general, it is found that the CO{sub 2} environment and coal rank have a significant effect on coal pyrolysis and char burnout. (orig.)

  16. Combustion Characteristics Of Agricultural Waste-Coal Char Blends

    International Nuclear Information System (INIS)

    Shortage of petroleum products, depletion of huge forest reserves for fuel purposes with its attendant erosion problems and other environmental considerations have necessitated investigations into other sources of fuel. In this wise. a set of seven types of briquettes were prepared from agricultural wastes such as rice husk, maize husk and saw-dust and blends of carbonized coal char. Strong and well-formed briquettes with good combustion characteristics were obtained. The results obtained from water boiling tests show that 2 litres of water could be boiled just under 23 minutes. Moisture contents and strengths of these briquettes were also determined and are discussed. The results show that wastes could be converted into useful fuel

  17. The removal of reactive dyes using high-ash char

    Directory of Open Access Journals (Sweden)

    Moreira R.F.P.M.

    2001-01-01

    Full Text Available The thermodynamics and kinetics of adsorption of reactive dyes on high-ash char was studied. Equilibrium data were obtained using the static method with controlled agitation at temperatures in the range of 30 to 60ºC. The Langmuir isotherm model was used to describe the equilibrium of adsorption, and the equilibrium parameters, R L, in the range of 0 to 1 indicate favorable adsorption. The amount of dye adsorbed increased as temperature increased from 30 to 40ºC, but above 40ºC the increase in temperature resulted in a decrease in the amount of dye adsorbed. The kinetic data presented are for controlled agitation at 50 rpm and constant temperature with dye concentrations in the range of 10 ppm to50 ppm. The film mass transfer coefficient, Kf, and the effective diffusivity inside the particle, De, were fitted to the experimental data. The results indicate that internal diffusion governs the adsorption rate.

  18. BONE CHAR BASED BUCKET DEFLUORIDATOR IN TANZANIAN HOUSEHOLDS

    DEFF Research Database (Denmark)

    Jacobsen, P.; Dahi, Elian

    1997-01-01

    A household defluoridator, made of a 20 L plastic bucket and 10 kg of bone char, is tested and found efficient to remove fluoride at a capacity of 1.1 mg/g. On an average, the defluoridator reduced the original contents of 8.5 mgF/L to 0.37 mgF/L, i.e. 95.6 %, for a period of 2 months, where 32.5 L...... were treated every day. The defluoridator could be manufactured locally in Ngurdoto village, Arusha Region Tanzania for a price of about 10 US $ per unit. The defluoridator is monitored as operated in 10 households. The defluoridator reduced the fluoride concentration from 10.5 mg/L to less than 1 mg...

  19. Implicit Coupling Approach for Simulation of Charring Carbon Ablators

    Science.gov (United States)

    Chen, Yih-Kanq; Gokcen, Tahir

    2013-01-01

    This study demonstrates that coupling of a material thermal response code and a flow solver with nonequilibrium gas/surface interaction for simulation of charring carbon ablators can be performed using an implicit approach. The material thermal response code used in this study is the three-dimensional version of Fully Implicit Ablation and Thermal response program, which predicts charring material thermal response and shape change on hypersonic space vehicles. The flow code solves the reacting Navier-Stokes equations using Data Parallel Line Relaxation method. Coupling between the material response and flow codes is performed by solving the surface mass balance in flow solver and the surface energy balance in material response code. Thus, the material surface recession is predicted in flow code, and the surface temperature and pyrolysis gas injection rate are computed in material response code. It is demonstrated that the time-lagged explicit approach is sufficient for simulations at low surface heating conditions, in which the surface ablation rate is not a strong function of the surface temperature. At elevated surface heating conditions, the implicit approach has to be taken, because the carbon ablation rate becomes a stiff function of the surface temperature, and thus the explicit approach appears to be inappropriate resulting in severe numerical oscillations of predicted surface temperature. Implicit coupling for simulation of arc-jet models is performed, and the predictions are compared with measured data. Implicit coupling for trajectory based simulation of Stardust fore-body heat shield is also conducted. The predicted stagnation point total recession is compared with that predicted using the chemical equilibrium surface assumption

  20. Leaching behaviour and ecotoxicity evaluation of chars from the pyrolysis of forestry biomass and polymeric materials.

    Science.gov (United States)

    Bernardo, M; Mendes, S; Lapa, N; Gonçalves, M; Mendes, B; Pinto, F; Lopes, H

    2014-09-01

    The main objective of this study was to assess the environmental risk of chars derived from the pyrolysis of mixtures of pine, plastics, and scrap tires, by studying their leaching potential and ecotoxicity. Relationships between chemical composition and ecotoxicity were established to identify contaminants responsible for toxicity. Since metallic contaminants were the focus of the present study, an EDTA washing step was applied to the chars to selectively remove metals that can be responsible for the observed toxicity. The results indicated that the introduction of biomass to the pyrolysis feedstock enhanced the acidity of chars and promote the mobilisation of inorganic compounds. Chars resulting from the pyrolysis of blends of pine and plastics did not produce ecotoxic eluates. A relationship between zinc concentrations in eluates and their ecotoxicity was found for chars obtained from mixtures with tires. A significant reduction in ecotoxicity was found when the chars were treated with EDTA, which was due to a significant reduction in zinc in chars after EDTA washing. PMID:24905691

  1. Kinetics characteristics of straw semi-char gasification with carbon dioxide.

    Science.gov (United States)

    Xiao, Ruirui; Yang, Wei

    2016-05-01

    The gasification process has promising potential as a solution for the current global energy problem. Kinetics characteristics of straw semi-char gasification were investigated. The main influence factors of gasification, which include bio-char particle size, pyrolysis temperature and pyrolysis atmosphere, were studied. The smaller the particle size is, the higher is the conversion rate. The gasification reactivity of semi-chars increases with pyrolysis temperature and reaches its maximum at approximately 400°C. The straw semi-char obtained in an H2 pyrolysis atmosphere has the best gasification reactivity, while the semi-char obtained in a CO2 atmosphere has the worst reactivity. In addition, characteristics of semi-char were systematically tested. A random pore model, unreacted core shrinking model and integrated model were employed to describe the reactive behavior of semi-chars. Gasification kinetics parameters were calculated. The random pore model fitting result is in better agreement with the experiments than that of the other two models. PMID:26890792

  2. Influence of fast pyrolysis conditions on yield and structural transformation of biomass chars

    DEFF Research Database (Denmark)

    Trubetskaya, Anna; Jensen, Peter Arendt; Jensen, Anker Degn;

    2015-01-01

    Fast pyrolysis of biomass (wood, straw, rice husk) and its major components (cellulose, hemicellulose, lignin) was conducted in a wire mesh reactor. The aim of this study was to understand the influence of temperature (350-1400 ° C), heating rate (10-3000 ° C/s), particle size (0.05-2 mm) and hol......Fast pyrolysis of biomass (wood, straw, rice husk) and its major components (cellulose, hemicellulose, lignin) was conducted in a wire mesh reactor. The aim of this study was to understand the influence of temperature (350-1400 ° C), heating rate (10-3000 ° C/s), particle size (0.05-2 mm......) and holding time (1-4 s) on the char morphology and char yield. Scanning electron microscopy (SEM) and elemental analysis were conducted to determine the effect of operating conditions on char softening and melting during pyrolysis. The char yield decreased with heating rate for rates ≤ 600 ° C/s; above...... that the heat treatment temperature had a larger influence on the char yield than the heating rate. Scanning electron microscopy indicated different types of biomass char plasticization influenced by the applied temperatures, heating rates, particle sizes and holding times, except for the rice husk char...

  3. Subcellular distribution of trace elements and liver histology of landlocked Arctic char (Salvelinus alpinus) sampled along a mercury contamination gradient.

    Science.gov (United States)

    Barst, Benjamin D; Rosabal, Maikel; Campbell, Peter G C; Muir, Derek G C; Wang, Xioawa; Köck, Günter; Drevnick, Paul E

    2016-05-01

    We sampled landlocked Arctic char (Salvelinus alpinus) from four lakes (Small, 9-Mile, North, Amituk) in the Canadian High Arctic that span a gradient of mercury contamination. Metals (Hg, Se, Tl, and Fe) were measured in char tissues to determine their relationships with health indices (relative condition factor and hepatosomatic index), stable nitrogen isotope ratios, and liver histology. A subcellular partitioning procedure was employed to determine how metals were distributed between potentially sensitive and detoxified compartments of Arctic char livers from a low- and high-mercury lake (Small Lake and Amituk Lake, respectively). Differences in health indices and metal concentrations among char populations were likely related to differences in feeding ecology. Concentrations of Hg, Se, and Tl were highest in the livers of Amituk char, whereas concentrations of Fe were highest in Small and 9-Mile char. At the subcellular level we found that although Amituk char had higher concentrations of Tl in whole liver than Small Lake char, they maintained a greater proportion of this metal in detoxified fractions, suggesting an attempt at detoxification. Mercury was found mainly in potentially sensitive fractions of both Small and Amituk Lake char, indicating that Arctic char are not effectively detoxifying this metal. Histological changes in char livers, mainly in the form of melano-macrophage aggregates and hepatic fibrosis, could be linked to the concentrations and subcellular distributions of essential or non-essential metals. PMID:26986088

  4. Effect of the coal particle size on pyrolysis and char reactivity for two types of coal and demineralized coal

    Energy Technology Data Exchange (ETDEWEB)

    Wenkui Zhu; Wenli Song; Weigang Lin [Chinese Academy of Sciences, Beijing (China). State Key Laboratory of Multi-phase Complex System

    2008-07-15

    A better understanding of the influence of particle size on pyrolysis and char reactivity is of crucial importance in optimizing the integrated process combining coal topping (coal fast pyrolysis) with char gasification. Different size fractions of two types of coal and demineralized coal were pyrolyzed in a spouted bed. The resulting chars were characterized by X-ray diffraction, and char reactivity was determined in a thermogravimetric analyzer (TGA). Within the range of particle sizes investigated, an increase in particle size results in an increase of char yield, which may be caused by the secondary reactions of volatile matters inside the coal particles. No significant difference in crystallinity was observed for the chars from different size fractions of the parent coals, while more crystallinity was observed for the chars from demineralized coals, which suggests that minerals in the coal play a role in the reduction of char crystallinity during pyrolysis. Char reactivity for raw coals decreased with the increasing of the particle size. For the demineralized coal samples, the change in char reactivity with the increasing of the particle size was reduced. Both the secondary reactions of volatiles and mineral distribution are believed to cause the influence of coal particle size on char reactivity. 19 refs., 7 figs., 3 tabs.

  5. Kinetics of char burnout and ash vaporization in coal-fired MHD combustors

    Energy Technology Data Exchange (ETDEWEB)

    Shuck, R.; Hastings, T.; Mims, C.; Sarofim, A.

    1979-01-01

    A computer model which simulates coal combustion in a simple MHD combustor was assembled. Data from parallel experimental work on devolatilization, char oxidation, and ash vaporization at MHD conditions provide input parameters to the model and provide checks on some of the assumptions therein. Trade-offs between ash vaporization and char utilization predicted by the model are shown. The importance of CO/sub 2/, H/sub 2/O, O/sub 2/, O, and OH to char oxidation is indicated from both theoretical and experimental considerations.

  6. Complete mitochondrial genome of the white char Salvelinus albus (Salmoniformes, Salmonidae).

    Science.gov (United States)

    Balakirev, Evgeniy S; Parensky, Valery A; Kovalev, Mikhail Yu; Ayala, Francisco J

    2016-09-01

    The complete mitochondrial genome was sequenced in two individuals of white char Salvelinus albus. The genome sequences are 16 653 bp in size, and the gene arrangement, composition, and size are very similar to the salmonid fish genomes published previously. The low level of sequence divergence detected between the genome of S. albus and the GenBank complete mitochondrial genomes of the Northern Dolly Varden char S. malma (KJ746618) and the Arctic char S. alpinus (AF154851) may likely be due to recent divergence of the species and/or historical hybridization and interspecific replacement of mtDNA. PMID:26358825

  7. Fuel gas and char from pyrolysis of waste paper in a microwave plasma reactor

    OpenAIRE

    Parin Khongkrapan, Patipat Thanompongchart, Nakorn Tippayawong, Tanongkiat Kiatsiriroat

    2013-01-01

    In this study, a microwave plasma reactor was used for pyrolysis of waste papers. The effects of different argon flow rates on char and gas generation were investigated. Changes in carbon and oxygen contents from those in paper to char were significant. Char yield of over 25 % was obtained with the heating value of about 38 MJ/kg. Average gas yield and total content of combustible fraction (CO, CH4 and H2) in the gas product were 2.56 m3/kg and 36 %, respectively. The heating value of gas pro...

  8. Effect of burn-off on physical and chemical properties of coal char; Gas ka shinko ni tomonau sekitan char no tokusei henka

    Energy Technology Data Exchange (ETDEWEB)

    Yamada, T.; Tamura, K.; Hashimoto, H.; Funaki, M.; Suzuki, T. [Kitami Institute of Technology, Hokkaido (Japan)

    1996-10-28

    For high-efficiency coal gasification, investigations were given on effect of coal chars with different conversion rates on coal gasification reactivity. In coal gasification, reactivity of char after pyrolysis governs the efficiency. The reference char conversion in CO2 gasification of coal (weight loss) changes linearly in the initial stage of the reaction, but the reactivity declines as the end point is approached. Char surface area is as large as 400 m{sup 2}/g in the initial stage with the conversion at 20%, but it decreases in the final stage. This phenomenon relates closely with changes in pore size and crystalline structure. Change in the Raman value R which shows incompleteness of char graphite structure and amorphous carbon ratio suggests that an active portion with high reactivity is oxidized preferentially, and a portion with low reactivity remains finally. Minerals in coal are known to accelerate the gasification. However, their catalytic effect is related with chemical forms, and complex as they may change into inactive sulfides and silicates under severe reaction conditions. Change in forms of calcium compounds may also be involved in decline of the reactivity in the latter stage. 8 refs., 4 figs.

  9. Pyrolysis of flax straw: Characterization of char, liquid, and gas as fuel

    Science.gov (United States)

    Tushar, Mohammad Shahed Hasan Khan

    The demand for energy continues to outstrip its supply and necessitates the development of renewable energy options. Biomass has been recognized as a major renewable energy source to supplement the declining fossil fuel source of energy. It is the most popular form of renewable energy and, currently, biofuel production is becoming more promising. Being carbon neutral, readily available, and low in sulphur content makes biomass a very promising source of renewable energy. In the present research, both the isothermal and non-isothermal pressurized pyrolysis of flax straw is studied for the first time. In case of isothermal pyrolysis, the influence of pyrolysis temperature and reaction time on char yield and morphology was investigated. The applied pyrolysis temperature was varied between 300 and 500°C. The reaction time was varied from 15 to 60 min. The char yield was found to decrease as pyrolysis temperature and reaction time increased. The char structure and surface morphology were thoroughly investigated by means of x-ray diffraction (XRD), temperature-programmed oxidation (TPO), and scanning electron microscopy (SEM). The degree of porosity and graphitization increased as pyrolysis temperature and time increased. In fact, the experiment performed at 500°C for 1h duration did not yield any char; only residual ash could be obtained. The TPO studies on the char samples corroborated the XRD findings and showed the presence of two types of carbon, namely, amorphous filamentous carbon and graphitic carbon. A thermogravimetric analysis (TGA) of the char was performed to gain an understanding of combustion kinetics and reactivity. It implied that the reactivity of the char decreases as temperature increases, and this finding is well supported by the TPO, TGA, SEM, and XRD characterization data. Furthermore, an empirical global model was devised based on the power law to estimate activation energy and other kinetic parameters. For the non-isothermal pressurized

  10. Sorption of diuron, atrazine, and copper ion on chars with long-term natural oxidation in soils

    Science.gov (United States)

    Cheng, C.; Lin, T.; Lai, C.

    2011-12-01

    Biochar has been proposed as a measure to sequestrate carbon (C) and to increase soil fertility in sustainable agriculture. However, its sorption characteristics to herbicides, such as lowing herbicides efficacy, may constrain its agricultural application. This assertion may be arguable because most studies so far were conducted with the newly produced char and barely considered the "ageing effect" of old char since it could be oxidized over long time. In this study, historical char samples were collected and compared with the newly produced char. Batch sorption studies of diuron, atrazine, and copper ion onto chars was performed. Greater sorption of Cu was observed on the historical char samples and reached a saturated sorption at 30 mg g-1 for Cu, much higher adsorption value than newly produced char at 4 mg g-1. In contrast, sorption of diuron and atrazine on newly produced char had the highest sorption capacity than the historical char samples. The historical chars also had much higher negative charge than the newly produced char, but its surface area were lower than the new char. The results indicated that change in surface functional groups through natural oxidation rather than the change of surface area may have more pronounced influences on sorption characteristics, in which the negative charge on the historical chars' surface could hinder the adsorption of diuron and atrazine while enhance the sorption to copper ion. Biological assay to test the toxicity of diuron and copper ion for both historical and new chars on rye seed were conducted and will be presented in our poster.

  11. Thermal treatment and foaming of chars obtained from almond shells: kinetic study

    Energy Technology Data Exchange (ETDEWEB)

    Marcilla, A.; Conesa, J.A.; Asensio, M.; Garcia-Garcia, S.M. [University of Alicante, Alicante (Spain). Dept. of Chemical Engineering

    2000-05-01

    The influence of a combined thermal treatment on the density of chars obtained from almond shells has been investigated. The thermal treatment involves two steps at different heating rates; the first one up to temperatures of 225-400{degree}C, and the second one up to 850{degree}C. Thermogravimetric experiments have been carried out with the intermediate chars obtained after treatment revealing the evolution of the different fractions of the almond shells (i.e. hemicellulose, cellulose and lignin), and their influence on the final density of the chars. An intermediate treatment, where the gases evolved from the last remaining fractions of the cellulose coincide with the char in a fluid or soft state, is required to foam the particles. A kinetic model has been applied to quantify, with excellent results, the evolution of the different fractions. 23 refs., 5 figs., 2 tabs.

  12. Prediction of the burnout behaviour of chars derived from coal-biomass blends

    Energy Technology Data Exchange (ETDEWEB)

    Tao Wu; Mei Gong; Edward Lester [University of Nottingham, Nottingham (United Kingdom). School of Chemical, Environmental and Mining Engineering

    2007-07-01

    Nowadays, biomass has been considered an alternative fuel to coal and is being used in power plants to replace part of coal used. This study is to investigate the potential of burning biomass with coal and its impacts on burnout levels. Daw Mill coal was selected for burnout modelling together with three biomasses, Cereal, PKE and Olive Cake. Chars were prepared (75-106 micron) and characterised using image analysis methods as in input data into the char burnout model (ChB) which was adapted to allow the prediction of char burnout of biomass-coal blends under typical pf combustion conditions. The burnout performance of four blend compositions for each biomass were modelled (5%, 10%, 20% and 30%). In practice, the low heating-value of biomass produces a lower flame temperature which can lead to lower levels of char burn-out. The effect is closely linked with the type of biomass used. 36 refs., 4 figs., 1 tab.

  13. STRUCTURE-BASED PREDICTIVE MODEL FOR COAL CHAR COMBUSTION

    Energy Technology Data Exchange (ETDEWEB)

    CHRISTOPHER M. HADAD; JOSEPH M. CALO; ROBERT H. ESSENHIGH; ROBERT H. HURT

    1998-06-04

    During the past quarter of this project, significant progress continued was made on both major technical tasks. Progress was made at OSU on advancing the application of computational chemistry to oxidative attack on model polyaromatic hydrocarbons (PAHs) and graphitic structures. This work is directed at the application of quantitative ab initio molecular orbital theory to address the decomposition products and mechanisms of coal char reactivity. Previously, it was shown that the �hybrid� B3LYP method can be used to provide quantitative information concerning the stability of the corresponding radicals that arise by hydrogen atom abstraction from monocyclic aromatic rings. In the most recent quarter, these approaches have been extended to larger carbocyclic ring systems, such as coronene, in order to compare the properties of a large carbonaceous PAH to that of the smaller, monocyclic aromatic systems. It was concluded that, at least for bond dissociation energy considerations, the properties of the large PAHs can be modeled reasonably well by smaller systems. In addition to the preceding work, investigations were initiated on the interaction of selected radicals in the �radical pool� with the different types of aromatic structures. In particular, the different pathways for addition vs. abstraction to benzene and furan by H and OH radicals were examined. Thus far, the addition channel appears to be significantly favored over abstraction on both kinetic and thermochemical grounds. Experimental work at Brown University in support of the development of predictive structural models of coal char combustion was focused on elucidating the role of coal mineral matter impurities on reactivity. An �inverse� approach was used where a carbon material was doped with coal mineral matter. The carbon material was derived from a high carbon content fly ash (Fly Ash 23 from the Salem Basin Power Plant. The ash was obtained from Pittsburgh #8 coal (PSOC 1451). Doped

  14. Fate of small charred particles in soils - importance of aggregation

    Science.gov (United States)

    Mueller, C. W.; Pechenkina, N.; Grünz, G.; Kölbl, A.; Steffens, M.; Heister, K.; Kögel-Knabner, I.

    2009-04-01

    Historic and recent fires affect a broad range of terrestrial ecosystems and are reflected in the composition of soil organic matter (SOM). Although the assignments of different sources and pools of black carbon (BC) are still under debate, the importance of BC for carbon (C) storage, nutrient supply and contaminant sorption is well recognized. Nevertheless, how processes of encapsulation of BC into aggregates may influence fate and properties of BC still needs further research. We observed small highly aromatic particulate OM (oPOMsmall, aromatic micro-scale charred particles and mineral bound SOM in Haplic Chernozems from Central Russia. We fractionated the soils by means of density to obtain particulate and mineral bound SOM fractions. The chemical composition of the obtained fractions was studied by solid-state 13C-NMR spectroscopy and energy dispersive X-ray spectroscopy (EDX). For visualization of the particles and aggregates we used scanning electron microscopy (SEM) and nano-scale secondary ion mass spectrometry (NanoSIMS). The importance of oxides for aggregate formation was elucidated by analyses of extractable Fe. Furthermore, we incubated the oPOMsmall fraction at 20°C in batch experiments to study the aggregate formation of charred particles with time. To track the fate of OM on new formed aggregates, we used a labelled amino acid mixture (min. 98 atom% 13C and 15N) as readily bioavailable OM input and isotopic tracer. The matrix of the intact soil aggregates, embedded in epoxy resin, was dominated by densely packed clay particles. At all depths particulate SOM was quantitatively dominated by the aromatic oPOM fractions, inter-aggregate POM was almost absent at higher depths. The oPOMsmall showed mainly amorphous structures and very few plant tissue structures as revealed by SEM. The oPOMsmall fraction showed a drastic increase in the content of aromatic C with depth along with decreasing aliphatic C in the thick A horizons. Almost the entire OM of

  15. Leaching behaviour and ecotoxicity evaluation of chars from the pyrolysis of forestry biomass and polymeric materials

    OpenAIRE

    Bernardo, Maria S.; Mendes, S.; Lapa, N.; Gonçalves, Margarida; Mendes, Benilde; Pinto, Filomena; Lopes, M. Helena

    2014-01-01

    The main objective of this study was to assess the environmental risk of chars derived from the pyrolysis of mixtures of pine, plastics, and scrap tires, by studying their leaching potential and ecotoxicity. Relationships between chemical composition and ecotoxicity were established to identify contaminants responsible for toxicity. Since metallic contaminants were the focus of the present study, an EDTA washing step was applied to the chars to selectively remove metals that can be responsibl...

  16. Influence of Pyrolysis Temperature on Rice Husk Char Characteristics and Its Tar Adsorption Capability

    OpenAIRE

    Anchan Paethanom; Kunio Yoshikawa

    2012-01-01

    A biomass waste, rice husk, was inspected by thermoanalytical investigation to evaluate its capability as an adsorbent medium for tar removal. The pyrolysis process has been applied to the rice husk material at different temperatures 600, 800 and 1000 °C with 20 °C/min heating rate, to investigate two topics: (1) influence of temperature on characterization of rice husk char and; (2) adsorption capability of rice husk char for tar removal. The results showed that subsequent ...

  17. Techno-Economic Assessment of Pyrolysis Char Production and Application – A Review

    OpenAIRE

    KUPPENS, Tom; VAN DAEL, Miet; Vanreppelen, Kenny; Carleer, Robert; Yperman, Jan; SCHREURS, Sonja; Van Passel, Steven

    2014-01-01

    Many organic residue streams such as pig manure are not or inefficiently used, although they can be converted into valuable materials, as well as energy, using pyrolysis. The yield of the pyrolysis products (i.e. oil, gas and char) is dependent on the process conditions and the feedstock used. Char as a soil amendment or activated carbon are interesting options for valorization of biomass residues. Here, a review is presented of the techno-economic potential of both valorization options based...

  18. Mixed waste treatment using the ChemChar thermolytic detoxification technique

    Energy Technology Data Exchange (ETDEWEB)

    Kuchynka, D. [Mirage Systems, Sunnyvale, CA (United States)

    1995-10-01

    The diversity of mixed waste matrices contained at Department of Energy sites that require treatment preclude a single, universal treatment technology capable of handling sludges, solids, heterogeneous debris, aqueous and organic liquids and soils. This report describes the ChemChar thermolytic detoxification process. The process is a thermal, chemically reductive technology that converts the organic portion of mixed wastes to a synthesis gas, while simultaneously absorbing volatile inorganics on a carbon-based char.

  19. Development of coconut pith chars towards high elemental mercury adsorption performance - Effect of pyrolysis temperatures.

    Science.gov (United States)

    Johari, Khairiraihanna; Saman, Norasikin; Song, Shiow Tien; Cheu, Siew Chin; Kong, Helen; Mat, Hanapi

    2016-08-01

    In this study, chars from coconut pith (CP) were prepared aiming for superior adsorption towards elemental mercury (Hg(o)). The yield, proximate analysis, textural characteristics, surface functional groups and elemental composition analyses of the chars produced at pyrolysis temperature of 300 °C, 500 °C, 700 °C and 900 °C were compared. The surface area, pore volume, ash and carbon content of chars increased, while the yield and moisture content decreased with increasing pyrolysis temperatures. The changing of physical and chemical properties of the chars produced at variety pyrolysis temperature was much effect on the Hg(o) adsorption performance and definitely provides important information on the Hg(o) adsorption mechanism. The highest Hg(o) adsorption capacity was observed for CP900 (6067.49 μg/g), followed by CP700 (2395.98 μg/g), CP500 (289.76 μg/g), CP300 (1.68 μg/g), and CP (0.73 μg/g). The equilibrium data were well described by the Freundlich adsorption isotherm model. The pseudo-second order best described the kinetic data of the Hg(o) adsorption onto CP and CP300. For chars produced at higher pyrolysis temperature, however, the pseudo-zero order and pseudo-second order fitted well for the adsorption and breakthrough regions, respectively. The Hg(o) adsorption capacity of chars obtained from high pyrolysis temperature of CP significantly outperformed the commercial activated carbon (Darco KB-B) as well as superior to chars reported in the literature indicating the CP can be used as a precursor for preparation of chars as elemental mercury adsorbents. PMID:27160635

  20. Fluoride removal from drinking water by adsorption using bone char as a biosorbent

    OpenAIRE

    Ma, W; Ya, F.; Wang, R.; Zhao, Y. Q.

    2008-01-01

    As a biomass material, bone char was investigated for the feasibility to be used as a cost-effective biosorbent for fluoride removal from drinking water in groundwater environment. Based on the batch tests with natural tourmalin and active alumina being the reference adsorbents, BF (referring to bone char) has demonstrated a higher fluoride adsorption capacity. This capacity was found being increased with the increase of fluoride concentration. Furthermore, BF based column adsorption experime...

  1. Bio-char derived from sewage sludge by liquefaction: Characterization and application for dye adsorption

    Science.gov (United States)

    Leng, Lijian; Yuan, Xingzhong; Huang, Huajun; Shao, Jianguang; Wang, Hou; Chen, Xiaohong; Zeng, Guangming

    2015-08-01

    Bio-chars produced by liquefaction of sewage sludge with methanol, ethanol, or acetone as the solvent at 260-380 °C were characterized in terms of their elemental composition, thermogravimetric characteristics, surface area and pore size distribution, and oxygen-containing functional groups composition. The surface area and total volume of the bio-chars were low, but the contents of oxygen-containing functional groups were high. The bio-chars were effective on Malachite green (MG) and Methylene blue (MB) removal from aqueous solution. The MG adsorption equilibrium data showed excellent fit to the Langmuir model and the kinetic data fitted well to the Pseudo-second-order model. Thermodynamic investigations indicated that MG adsorption on bio-char was spontaneous and endothermic. The MG adsorption mechanism appears to be associated with cation release and functional group participation. Additionally, liquefaction of SS with acetone as the solvent at low temperature (280 °C) would favor the production of bio-char adsorbent in terms of bio-char yield and MG and MB adsorption capacity.

  2. ENHANCING ASPHALT RHEOLOGICAL BEHAVIOR AND AGING SUSCEPTIBILITY USING BIO-CHAR AND NANO-CLAY

    Directory of Open Access Journals (Sweden)

    Renaldo C. Walters

    2014-01-01

    Full Text Available The life expectancy of Asphalt Binder (AB has been negatively impacted by the harsh bombardment of UV rays. UV rays cause asphalt to oxidize faster, which results in deterioration of asphalt rheological characteristics that can lead to pavement distresses. This study investigates the impact of bio-char and nano-clay of asphalt rheological properties. Two nano scale materials were used for this study were nano-clay and bio-char. Nano-clay (Cloisite 30B is a naturally occurring inorganic mineral. Bio-char is the waste product from bio-binder production. Bio-binder is produced from swine manure using a thermochemical conversion process. This process is then followed by a filtration procedure where the bio-char is produced. Chemical and physical properties of bio-char showed a significant presence of carbon which could in turn enhance asphalt flow properties and reduce the rate of asphalt oxidation. In this study several mixtures are designed and evaluated using Rotational Viscometer testing (RV and X-Ray Diffraction (XRD. Nano-clay is blended at 2 and 4% by weight, with and without bio-binder (5% by weight of dry mass. Bio-char is grinded to nano scale and added to the virgin asphalt binder (PG 64-22 at 2, 5 and 10% by weight. The study results showed that introduction of nano-clay could be effective in reducing temperature susceptibility of asphalt binder.

  3. Improvement of biomass char-CO2 gasification reactivity using microwave irradiation and natural catalyst

    International Nuclear Information System (INIS)

    Highlights: • We study microwave-induced gasification of EFB ash-loaded biomass char with CO2. • Synergistic effect of microwave and catalyst resulted in CO2 conversion of 93%. • Gasification of pristine char using conventional heating gives CO2 conversion of 58%. • Ea of 74 and 247 kJ/mol were obtained for microwave and conventional CO2 gasification. - Abstract: In char-CO2 gasification, the highly endothermic nature of the Boudouard reaction (CO2 (g) + C (s) ↔ 2CO (g)) dictates use of very high temperatures to shift the equilibrium towards CO production. In this study, such high temperature (750–900 °C) was provided by microwave irradiation. A microwave heating system was developed to perform the gasification tests by passing CO2 through a packed bed of oil palm shell (OPS) char. In order to speed up the microwave-induced CO2 gasification, ash of palm empty fruit bunch (EFB) was used as natural catalyst (rich in potassium) and incorporated into the skeleton of the OPS char. The synergistic effect of microwave and catalyst concluded to very encouraging results, where a CO2 conversion of 93% was achieved at 900 °C, within 60 min microwave gasification. In comparison, CO2 conversion in thermal gasification (conventional heating) of pristine OPS char was only 58% under the same operating condition

  4. The potential applications of using compost chars for removing the hydrophobic herbicide atrazine from solution

    Science.gov (United States)

    Tsui, L.; Roy, W.R.

    2008-01-01

    One commercial compost sample was pyrolyzed to produce chars as a sorbent for removing the herbicide atrazine from solution. The sorption behavior of compost-based char was compared with that of an activated carbon derived from corn stillage. When compost was pyrolyzed, the char yield was greater than 45% when heated under air, and 52% when heated under N2. In contrast, when the corn stillage was pyrolyzed under N2, the yield was only 22%. The N2-BET surface area of corn stillage activated carbon was 439 m2/g, which was much greater than the maximum compost char surface area of 72 m2/g. However, the sorption affinity of the compost char for dissolved atrazine was comparable to that of the corn stillage activated carbon. This similarity could have resulted from the initial organic waste being subjected to a relatively long period of thermal processes during composting, and thus, the compost was more thermally stable when compared with the raw materials. In addition, microorganisms transformed the organic wastes into amorphous humic substances, and thus, it was likely that the microporisity was enhanced. Although this micropore structure could not be detected by the N2-BET method, it was apparent in the atrazine sorption experiment. Overall, the experimental results suggested that the compost sample in current study was a relatively stable material thermally for producing char, and that it has the potential as a feed stock for making high-quality activated carbon. ?? 2007 Elsevier Ltd. All rights reserved.

  5. Improvement of biomass char-CO{sub 2} gasification reactivity using microwave irradiation and natural catalyst

    Energy Technology Data Exchange (ETDEWEB)

    Lahijani, Pooya, E-mail: pooya.lahijani@gmail.com [Biomass and Bioenergy Laboratory, School of Mechanical Engineering, Universiti Sains Malaysia, 14300 Nibong Tebal, Pulau Pinang (Malaysia); Mohammadi, Maedeh, E-mail: m.mohammadi@nit.ac.ir [Faculty of Chemical Engineering, Babol Noushirvani University of Technology, 47148 Babol (Iran, Islamic Republic of); Zainal, Zainal Alimuddin, E-mail: mezainal@eng.usm.my [Biomass and Bioenergy Laboratory, School of Mechanical Engineering, Universiti Sains Malaysia, 14300 Nibong Tebal, Pulau Pinang (Malaysia); Mohamed, Abdul Rahman, E-mail: chrahman@usm.my [Low Carbon Economy (LCE) Research Group, School of Chemical Engineering, Engineering Campus, Universiti Sains Malaysia, 14300 Nibong Tebal, Pulau Pinang (Malaysia)

    2015-03-20

    Highlights: • We study microwave-induced gasification of EFB ash-loaded biomass char with CO{sub 2}. • Synergistic effect of microwave and catalyst resulted in CO{sub 2} conversion of 93%. • Gasification of pristine char using conventional heating gives CO{sub 2} conversion of 58%. • E{sub a} of 74 and 247 kJ/mol were obtained for microwave and conventional CO{sub 2} gasification. - Abstract: In char-CO{sub 2} gasification, the highly endothermic nature of the Boudouard reaction (CO{sub 2} (g) + C (s) ↔ 2CO (g)) dictates use of very high temperatures to shift the equilibrium towards CO production. In this study, such high temperature (750–900 °C) was provided by microwave irradiation. A microwave heating system was developed to perform the gasification tests by passing CO{sub 2} through a packed bed of oil palm shell (OPS) char. In order to speed up the microwave-induced CO{sub 2} gasification, ash of palm empty fruit bunch (EFB) was used as natural catalyst (rich in potassium) and incorporated into the skeleton of the OPS char. The synergistic effect of microwave and catalyst concluded to very encouraging results, where a CO{sub 2} conversion of 93% was achieved at 900 °C, within 60 min microwave gasification. In comparison, CO{sub 2} conversion in thermal gasification (conventional heating) of pristine OPS char was only 58% under the same operating condition.

  6. Effects of Charred Fructus Crataegi on the contractilily of isolated rat gastric and intestine muscle strips

    Institute of Scientific and Technical Information of China (English)

    ZHANG Hou-li; DIAO Yun-peng; LIU Zhi-hao; HUANG Shan-shan; MA Xiao-chi; LIN Yuan

    2008-01-01

    Objective The purpose of the study is to investigate the effects of Charred Fructus Crataegi Alcohol Extract on contractililty of isolated rat gastric and intesting smooth muscle strips. Methods Isolated rat intestine was selected in the assay to test the effects of Charred Fructus Crataegi Alcohol Extract on contractilty of isolated rat gastric and intestine smooth muscle strips using Krebs' solution, to observe the effects of in the presence of acetylcholine or atropine. Results Charred Fructus Crataegi Alcohol Extract in the range of 2-8 rag crude drugs/mL could significantly reduce the contractility of rat gastric and intestine smooth muscle strips in a dose-dependent manner, and Charred Fructus Crataegi Alcohol Extract 8 mg·mL-1(crude drugs) could inhibit the stimulation induced by acetylcholine. Charred Fructus Crataegi Alcohol Extract 8 mg·mL-1(crude drugs) was found to have a inhibiton of the relaxtion concurrently used with atropin. Conclusions The results suggest that Charred Fructus Crataegi Alcohol Extract has prominent inhibitory effects on the contractile activity of isolated rat gastric and intestine smooth muscle strips.

  7. High quality syngas production from microwave pyrolysis of rice husk with char-supported metallic catalysts.

    Science.gov (United States)

    Zhang, Shuping; Dong, Qing; Zhang, Li; Xiong, Yuanquan

    2015-09-01

    This study aimed to obtain the maximum possible gas yield and the high quality syngas production from microwave pyrolysis of rice husk with rice husk char and rice husk char-supported metallic (Ni, Fe and Cu) catalysts. The rice husk char-supported metallic catalysts had developed pore structure and catalytic activity for gas productions and tar conversion. The temperature-rising characteristic, product yields, properties of gas products and tar conversion mechanisms were investigated. It was found that three rice husk char-supported metallic catalysts improved the microwave absorption capability and increased heating rate and final temperature. Rice husk char-supported Ni catalyst presented most effective effects on gas production, e.g. the gas yield is 53.9%, and the volume concentration of desired syngas is 69.96%. Rice husk char-supported Ni and Fe catalysts played pivotal roles in tar conversion that less heavy compounds can be detected along with the reduction of organic compound number. PMID:25974618

  8. Role of char during reburning of nitrogen oxides. Ninth quarterly report, October 1, 1995--December 31, 1995

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Wei-Yin; Lu, Te-Chang [Mississippi Univ., University, MS (United States). Dept. of Chemical Engineering; Fan, L.T.; Yashima, Mutsuo [Kansas State Univ., Manhattan, KS (United States). Dept. of Chemical Engineering

    1996-01-31

    During this quarter, we have investigated rates and product compositions of NO reduction on chars in gases. N{sub 2} and CO{sub 2} internal surface areas of chars, selected from runs of various pyrolysis and reaction conditions have been measured to assist in interpreting the experimental results. Implications of Langmuir- Hinshelwood mechanisms and mass transfer limitations were examined. Oxidants suppress NO reduction on bituminous coal char more than on lignite char. Observations suggest that NO adsorption and desorption of stable surface oxygen complexes are potentially important rate- limiting steps and may be catalyzed by mineral matter during reburning with lignite char. Relative inert nature of lignite char to CO{sub 2} presence may have potential value in use of fuel system involving both solid and volatile fuels. Lignite char produced at 950 C and zero holding time has higher reactivity than that produced at 1100 C and 5 min holding time. Bituminous coal chars produced at these two conditions, however, have similar reactivity with NO. Internal surface areas of both type chars vary with pyrolysis conditions and gas composition in the subsequent reaction. When oxidants are introduced in the feed, internal surface areas of these two chars vary in opposite directions.

  9. Thermogravimetric study on the influence of structural, textural and chemical properties of biomass chars on CO2 gasification reactivity

    International Nuclear Information System (INIS)

    The present investigation aims to examine the influence of textural, structural and chemical properties of biomass chars on the CO2 gasification rate. Various lignocellulosic biomass chars were prepared under the same conditions. Different analytical techniques were used to determine the char properties such as Scanning Electronic Microscopy, nitrogen adsorption manometry, Raman spectroscopy and X Ray Fluorescence. Gasification tests were carried out in a thermobalance under 20% CO2 in nitrogen at 800 °C. Significant differences of the total average reactivity were observed with a factor of 2 between the prepared chars. Moreover, different behaviors of gasification rate profiles versus conversion were obtained. This difference of behavior appeared to be correlated with the biomass char properties. Hence, up to 70% of conversion, the gasification rate was shown to depend on the char external surface and the potassium content. At higher conversion ratio, a satisfactory correlation between the Catalytic Index and the average gasification rate was identified. The results highlight the importance of knowing both textural and structural properties and mineral contents of biomass chars to predict fuel reactivity during CO2 gasification processes. Such behavior prediction is highly important in the gasifiers design for char conversion. - Highlights: • CO2 gasification reactivity of various lignocellulosic chars were examined. • Chars properties affect strongly samples gasification behavior. • Initial gasification rate is affected by external surface, K content and D3/G ratio. • Gasification rate behavior depends on the Alkali index at high conversion

  10. Silicon-doped carbon semiconductor from rice husk char

    International Nuclear Information System (INIS)

    The aim of this work is to prepare semiconductor grade carbon from the agricultural residue, rice husk. Rice husk on pyrolysis in a fixed bed reactor produces solid char which when mixed with metallic magnesium powder at a certain ratio and being heated in a closed steel tube reactor at a high temperature results in formation of silicon-doped carbon. The resistivity vs. temperature characteristics shows that material is semiconducting in nature. Suitable doping with phosphorous and boron results in n- and p-type characteristics in the silicon-doped carbon. The electronic parameters of the material are evaluated using Hall measurement technique and four-probe method. The I-V characteristic of a p-n junction prepared by suitable doping of the silicon-doped carbon shows a current ramp in the forward direction and a sharp rise in reverse current like a diode. The method of production of such semiconductor material can generate a new avenue for semiconductor industry

  11. Coke, char and organic waste behaviour in the blast furnace with high injection rate

    Directory of Open Access Journals (Sweden)

    Gudenau, H. W.

    2003-10-01

    Full Text Available Blast furnace operation with low coke rate, high amount of auxiliary hydrocarbons and use of nut coke causes a change in coke quality requirements. In particular, not burned in the raceway residues of injected substances (char and ash can influence the coke behaviour. Therefore combustion efficiency of various organic wastes with and without pulverized coal injection (PCI and coal char has been investigated under the raceway simulation conditions. Mixing of various substances improves their combustion efficiency. Study on coke gasification by carbon dioxide in the presence of char showed that with the increase of char concentration, coke strength reduction becomes smaller. The reactivity of char with CO2 is higher than that of coke. Therefore char is consumed preferentially. In presence of injected char, total pore volume in coke and its wear resistance were increased. Coke reactivity and microstructure in the presence of various kinds of ash has been studied. Many ash spheres were observed on the surface of coke matrix and its size was dependent on ash properties.

    La operación del horno alto con una tasa baja de coque, una cantidad elevada de hidrocarburos auxiliares y el empleo de coque calibrado, origina un cambio en las necesidades de calidad del coque. En particular, pueden influir en el comportamiento del coque los residuos inquemados en el raceway (cavidad enfrente a las toberas del horno de las sustancias que se inyectan (char y cenizas. El char es el residuo de carbón que se origina después que el carbón libera sus sustancias volátiles. Por tanto, se ha investigado la eficiencia de la combustión de varios residuos orgánicos con y sin inyección de carbón pulverizado (ICP y char, bajo las condiciones de simulación del raceway. La mezcla de varias sustancias mejora la eficiencia a la combustión. El estudio de la gasificación del coque por el dióxido de carbono en la

  12. Conversion of char nitrogen to N2 under incomplete combustion conditions; Fukanzen nensho jokenka ni okeru char chuchisso no N2 eno tenka

    Energy Technology Data Exchange (ETDEWEB)

    Zhuang, Q.; Yamauchi, A.; Oshima, Y.; Wu, Z.; Otsuka, Y. [Tohoku University, Sendai (Japan). Institute for Chemical Reaction Science

    1996-10-28

    The effect of combustion conditions on conversion of char nitrogen to N2 was studied in the combustion experiment of char obtained by pyrolysis of coal. Char specimen was prepared by holding ZN coal of Chinese lignite in Ar atmosphere at 1123K for one hour. A batch scale quartz-made fluidized bed reactor was used for combustion experiment. After the specimen was fluidized in reaction gas, it was rapidly heated to start combustion reaction. CO, CO2 and N2 in produced gases were online measured by gas chromatography (GC). As the experimental result, under the incomplete combustion condition where a large amount of CO was produced by consuming almost all of O2, no NOx and N2O produced from char were found, and almost all of N-containing gas was N2. At the final stage of combustion, pyridinic-N disappeared completely, and pyrrolic-N decreased, while O-containing nitrogen complexes became a main component. It was thus suggested that O-containing nitrogen complexes are playing the role of intermediate product in combustion reaction. 7 refs., 4 figs., 1 tab.

  13. Coal devolatilization and char conversion under suspension fired conditions in O2/N2 and O2/CO2 atmospheres

    DEFF Research Database (Denmark)

    Jensen, Anker Degn; Brix, Jacob; Jensen, Peter Arendt

    2010-01-01

    indicates that a shift from air to oxy-fuel combustion does not influence the devolatilization process significantly. Char combustion experiments yielded similar char conversion profiles when N2 was replaced with CO2 under conditions where combustion was primarily controlled by chemical kinetics. When char......The aim of the present investigation is to examine differences between O2/N2 and O2/CO2 atmospheres during devolatilization and char conversion of a bituminous coal at conditions covering temperatures between 1173 K and 1673 K and inlet oxygen concentrations between 5 and 28 vol.%. The experiments...... have been carried out in an electrically heated entrained flow reactor that is designed to simulate the conditions in a suspension fired boiler. Coal devolatilized in N2 and CO2 atmospheres provided similar results regarding char morphology, char N2-BET surface area and volatile yield. This strongly...

  14. The effect of 150μm expandable graphite on char expansion of intumescent fire retardant coating

    Energy Technology Data Exchange (ETDEWEB)

    Ullah, Sami, E-mail: samichemist1@gmail.com; Shariff, A. M., E-mail: azmish@petronas.com.my, E-mail: azmibustam@petronas.com.my; Bustam, M. A., E-mail: azmish@petronas.com.my, E-mail: azmibustam@petronas.com.my [Research Center for Carbon Dioxide Capture, Department of Chemical Engineering, Universiti Techologi PETRONAS, Bandar Sri Iskandar, Tronoh 31750 Perak (Malaysia); Ahmad, Faiz, E-mail: faizahmadster@gmail.com [Department of Mechanical Engineering, Universiti Techologi PETRONAS, Bandar Sri Iskandar, Tronoh 31750 Perak (Malaysia)

    2014-10-24

    Intumescent is defined as the swelling of certain substances to insulate the underlying substrate when they are heated. In this research work the effect of 150μm expandable graphite (EG) was studied on char expansion, char morphology and char composition of intumescent coating formulations (ICFs). To study the expansion and thermal properties of the coating, nine different formulations were prepared. The coatings were tested at 500 °C for one hour and physically were found very stable and well bound with the steel substrate. The morphology was studied by Scanning Electron Microscopy (SEM). The char composition was analysed by X-ray Diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR) techniques. EG above than 10.8wt% expands the char abruptly with uniform network structure and affect the outer surface of the char.

  15. The effect of 150μm expandable graphite on char expansion of intumescent fire retardant coating

    International Nuclear Information System (INIS)

    Intumescent is defined as the swelling of certain substances to insulate the underlying substrate when they are heated. In this research work the effect of 150μm expandable graphite (EG) was studied on char expansion, char morphology and char composition of intumescent coating formulations (ICFs). To study the expansion and thermal properties of the coating, nine different formulations were prepared. The coatings were tested at 500 °C for one hour and physically were found very stable and well bound with the steel substrate. The morphology was studied by Scanning Electron Microscopy (SEM). The char composition was analysed by X-ray Diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR) techniques. EG above than 10.8wt% expands the char abruptly with uniform network structure and affect the outer surface of the char

  16. Ash liberation from included minerals during combustion of pulverized coal: the relationship with char structure and burnout

    Energy Technology Data Exchange (ETDEWEB)

    Wu, H.; Wall, T.; Liu, G.; Bryant, G. [University of Newcastle, Callaghan, NSW (Australia). CRC for Black Coal Utilization and Dept. of Chemical Engineering

    1999-12-01

    In this study, the float fraction ({lt} specific gravity of 2.0) of a size cut (63-90 {mu}m) bituminous coal was combusted in a drop tube furnace (DTF) at a gas temperature of 1300{degree}C under an atmosphere of air, to investigate the ash liberation at five coal burnoff levels (35.5%, 54.3%, 70.1%, 87.1% and 95.6%). The data indicated that char structure determines the ash liberation at different burnoff levels. Fragmentation of porous char was found to be the determinative mechanism for formation of fine ash during the early and middle stages of char combustion, while coalescence of included mineral matter determines the coarse ash formed in the later stages of combustion. The investigation confirmed that the char morphology and structure play a key role in determining char fragmentation, char burnout history, and the ash liberation during combustion. 35 refs., 5 figs., 2 tabs.

  17. Using BPCA and pyrolysis-GC/MS patterns as a measure of charring intensity

    Science.gov (United States)

    Kaal, Joeri; Schneider, Maximilian P. W.; Schmidt, Michael W. I.

    2010-05-01

    Many questions remain on the molecular properties of Black C (organic fire residues such as charcoal and soot). Here we compare parameters from two methods that have recently shown to be related to the degree of thermal modification ("charring intensity") of charcoal-Black C: i) the proportion of mellitic acid (B6CA) among benzenepolycarboxylic acids in the BPCA method [1,2,3] and ii) the relative proportions and degree of alkylation of pyrolysis products from Black C in pyrolysis-GC/MS [4]. For that purpose we used laboratory chars from rice straw (grass) and chestnut wood (wood) produced at 200-1000 °C under N2 flow. The chars obtained at 450 °C are reference materials of the Black Carbon Ring Trial [5]. Positive correlations between the charring temperature and BPCA and pyrolysis patterns confirm that these methods can be used to study the degree of thermal impact of charred remains. Pyrolysis-GC/MS allowed us to track the thermal degradation of the major biocomponents lignin, polysaccharides, tannin, aliphatic chain lipids, triterpenoids, chlorophyll and proteins, mostly between 250 and 450 °C. The proportions of the pyrolysis products of Black C (benzene, toluene, benzonitrile, PAHs, etc.) and also the ratios that reflect the abundance of aliphatic cross-linkages between aromatic moieties (benzene/toluene, naphthalene/alkylnaphthalenes, benzofuran/alkylbenzofurans), increase with charring intensity. Nonetheless, chars obtained at T > 600 °C (especially for wood) gave low quality pyrograms and poor reproducibility because of high thermal stability. The relative contributions of B6CA, one of the molecular markers used for the BPCA method, are indicative for the degree of condensation of the chars. The BPCA approach showed a clear increase in the relative contribution of B6CA from ca. 5 % at 200 °C to ca. 95 % at 1000 °C, confirming the ability of this parameter to assess charring intensity. The relative contribution of B6CA remains almost constant at ca

  18. Role of char during reburning of nitrogen oxides. Seventh quarterly progress report, April 1, 1995--June 30, 1995

    Energy Technology Data Exchange (ETDEWEB)

    Wei-Yin Chen; Te-Chang Lu [Univ. of Mississippi, University, MS (United States); Fan, L.T.; Yashima, M. [Kansas State Univ., Manhattan, KS (United States)

    1995-08-11

    The progress in this quarter includes four parts. In the first segment, the implications of our data reported in the List quarter are discussed further. BET N{sub 2} surface area does not seems to be the only contributing factor to the remarkable activity of lignite char during reburning, and chars of different origins probably have different controlling steps in the overall surface reaction mechanisms. Unlike NO reduction in the gas phase, oxygen inhibits the heterogeneous mechanisms. The second part of this report justifies the use of our laminar flow reactor system for the measurement of reaction rate. Dispersion model is used in the analysis. An expression relating the rate constant with the experimentally obtainable NO conversion for our flow reactor have been derived. Rates of NO/char reaction for six series of experiments have been measured over the temperature range 800 to 1100{degrees}C. These six series of experiments have been conducted with two different chars, one bituminous coal char and one lignite char, and three different levels of feed NO concentrations, 200, 400 and 1000 ppm. Results from the comparison of char activities suggest that, in the absence of O{sub 2} and CO{sub 2}, the origin of char is not a significant factor for NO reduction. The CO/CO{sub 2} ratio in the products is higher than one under all test conditions, but the ratio increases with increasing feed NO concentrations. Recoveries of oxygen form the lignite char at temperatures above 1050{degrees}C is higher than 1 indicating gasification of organic oxygen in the char. Surface areas of selected chars after devolatilization and after reburning have been analyzed by BET in N{sub 2}. Results indicated char surface area changes after reburning, which is caused either by the higher temperature of reburning or by surface reaction.

  19. Computational investigations of low-emission burner facilities for char gas burning in a power boiler

    Science.gov (United States)

    Roslyakov, P. V.; Morozov, I. V.; Zaychenko, M. N.; Sidorkin, V. T.

    2016-04-01

    Various variants for the structure of low-emission burner facilities, which are meant for char gas burning in an operating TP-101 boiler of the Estonia power plant, are considered. The planned increase in volumes of shale reprocessing and, correspondingly, a rise in char gas volumes cause the necessity in their cocombustion. In this connection, there was a need to develop a burner facility with a given capacity, which yields effective char gas burning with the fulfillment of reliability and environmental requirements. For this purpose, the burner structure base was based on the staging burning of fuel with the gas recirculation. As a result of the preliminary analysis of possible structure variants, three types of early well-operated burner facilities were chosen: vortex burner with the supply of recirculation gases into the secondary air, vortex burner with the baffle supply of recirculation gases between flows of the primary and secondary air, and burner facility with the vortex pilot burner. Optimum structural characteristics and operation parameters were determined using numerical experiments. These experiments using ANSYS CFX bundled software of computational hydrodynamics were carried out with simulation of mixing, ignition, and burning of char gas. Numerical experiments determined the structural and operation parameters, which gave effective char gas burning and corresponded to required environmental standard on nitrogen oxide emission, for every type of the burner facility. The burner facility for char gas burning with the pilot diffusion burner in the central part was developed and made subject to computation results. Preliminary verification nature tests on the TP-101 boiler showed that the actual content of nitrogen oxides in burner flames of char gas did not exceed a claimed concentration of 150 ppm (200 mg/m3).

  20. Char characterization and DTF assays as tools to predict burnout of coal blends in power plants

    Energy Technology Data Exchange (ETDEWEB)

    C. Ulloa; A.G. Borrego; S. Helle; A.L. Gordon; X. Garcia [Universidad de Concepcion, Concepcion (Chile). Departamento de Ingenieria Quimica

    2005-02-01

    The aim of this study is to predict efficiency deviations in the combustion of coal blends in power plants. Combustion of blends, as compared to its single coals, shows that for some blends the behavior is non-additive in nature. Samples of coal feed and fly ashes from combustion of blends at two power plants, plus chars of the parent coals generated in a drop-tube furnace (DTF) at temperatures and heating rates similar to those found in the industrial boilers were used. Intrinsic kinetic parameters, burning profiles and petrographic characteristics of these chars correlated well with the burnout in power plants and DTF experiments. The blend combustion in a DTF reproduces both positive and negative burnout deviations from the expected weighted average. These burnout deviations have been previously attributed to parallel or parallel-series pathways of competition for oxygen. No deviations were found for blends of low rank coals of similar characteristics yielding chars close in morphology, optical texture and reactivity. Negative deviations were found for blends of coals differing moderately in rank and were interpreted as associated with long periods of competition. In this case, fly-ashes were enriched in material derived from the least reactive char, but also unburnt material attributed to the most reactive char was identified. Improved burnout compared to the weighted average was observed for blends of coals very different in rank, and interpreted as the result of a short interaction period, followed by a period where the less reactive char burns under conditions that are more favorable to its combustion. In this case, only unburned material from the least reactive char was identified in the fly-ashes. 20 refs., 9 figs., 5 tabs.

  1. Kinetics of woodchips char gasification with steam and carbon dioxide

    International Nuclear Information System (INIS)

    Kinetics of woodchips char gasification has been examined. Steam and CO2 were used as the gasifying agents. Differences and similarities between kinetics of steam gasification and CO2 gasification have been discussed. Comparison was conducted in terms of gasification duration, evolution of reaction rate with time and/or conversion, and effect of partial pressure on reaction rate. Reactor temperature was maintained at 900 oC. Partial pressure of gasifying agents varied from 1.5 bars to 0.6 bars in intervals of 0.3 bars. Steam and CO2 flow rates were chosen so that both gasifying agents had equal amount of oxygen content. CO2 gasification lasted for about 60 min while steam gasification lasted for about 22 min. The average reaction rate for steam gasification was almost twice that of CO2. Both reaction rate curves showed a peak value at certain degree of conversion. For steam gasification, the reaction rate peak was found to be at a degree of conversion of about 0.3. However, for CO2 gasification the reaction rate peak was found to be at a conversion degree of about 0.1. Reaction rates have been fitted using the random pore model (RPM). Average structural parameter, ψ for steam gasification and CO2 gasification was determined to be 9 and 2.1, respectively. Average rate constant at 900 oC was 0.065 min-1 for steam gasification and 0.031 min-1 for CO2 gasification. Change in partial pressure of gasifying agents did not affect the reaction rate for both steam and CO2 gasification.

  2. In situ catalyzed Boudouard reaction of coal char for solid oxide-based carbon fuel cells with improved performance

    International Nuclear Information System (INIS)

    Highlights: • Industrial coal char was used as a fuel for solid oxide-based carbon fuel cells. • The Boudouard reactivity of coal char is higher than that of a commercial activated carbon. • The mineral matter in coal char has a catalytic effect on the Boudouard reaction. • Added catalysts and the inherent catalysts synergetically improved cell output. - Abstract: The use of industrial coal char as a fuel source for an anode-supported solid oxide-based carbon fuel cell (SO-CFC) with a yttrium-stabilized zirconia electrolyte and La0.8Sr0.2MnO3 cathode was investigated. Both the Boudouard reactivity and electrochemical performance of the coal char samples are higher than those of activated carbon samples under the same conditions. The inherent catalytic activity of the metal species (FemOn, CaO, etc.) in the coal char mineral matter leads to good cell performance, even in the absence of an external catalyst. For example, the peak power density of a cell fueled with pure coal char is 100 mW cm−2 at 850 °C, and that of a cell fueled with coal char impregnated with an FemOn-alkaline metal oxide catalyst is 204 mW cm−2. These results suggest that using coal char as the fuel in SO-CFCs might be an attractive way to utilize abundant coal resources cleanly and efficiently, providing an alternative for future power generation

  3. Abundant and stable char residues in soils: implications for soil fertility and carbon sequestration.

    Science.gov (United States)

    Mao, J-D; Johnson, R L; Lehmann, J; Olk, D C; Neves, E G; Thompson, M L; Schmidt-Rohr, K

    2012-09-01

    Large-scale soil application of biochar may enhance soil fertility, increasing crop production for the growing human population, while also sequestering atmospheric carbon. But reaching these beneficial outcomes requires an understanding of the relationships among biochar's structure, stability, and contribution to soil fertility. Using quantitative (13)C nuclear magnetic resonance (NMR) spectroscopy, we show that Terra Preta soils (fertile anthropogenic dark earths in Amazonia that were enriched with char >800 years ago) consist predominantly of char residues composed of ~6 fused aromatic rings substituted by COO(-) groups that significantly increase the soils' cation-exchange capacity and thus the retention of plant nutrients. We also show that highly productive, grassland-derived soils in the U.S. (Mollisols) contain char (generated by presettlement fires) that is structurally comparable to char in the Terra Preta soils and much more abundant than previously thought (~40-50% of organic C). Our findings indicate that these oxidized char residues represent a particularly stable, abundant, and fertility-enhancing form of soil organic matter. PMID:22834642

  4. CFD Simulation of Entrained Flow Gasification With Improved Devolatilization and Char Consumption Submodels

    KAUST Repository

    Kumar, Mayank

    2009-01-01

    In this work, we use a CFD package to model the operation of a coal gasifier with the objective of assessing the impact of devolatilization and char consumption models on the accuracy of the results. Devolatilization is modeled using the Chemical Percolation Devolitilization (CPD) model. The traditional CPD models predict the rate and the amount of volatiles released but not their species composition. We show that the knowledge of devolatilization rates is not sufficient for the accurate prediction of char consumption and a quantitative description of the devolatilization products, including the chemical composition of the tar, is needed. We incorporate experimental data on devolatilization products combined with modeling of the tar composition and reactions to improve the prediction of syngas compositions and carbon conversion. We also apply the shrinking core model and the random pore model to describe char consumption in the CFD simulations. Analysis of the results indicates distinct regimes of kinetic and diffusion control depending on the particle radius and injection conditions for both char oxidation and gasification reactions. The random pore model with Langmuir-Hinshelwood reaction kinetics are found to be better at predicting carbon conversion and exit syngas composition than the shrinking core model with Arrhenius kinetics. In addition, we gain qualitative and quantitative insights into the impact of the ash layer surrounding the char particle on the reaction rate. Copyright © 2010 by ASME.

  5. Evaluación de la reducibilidad de un mineral de hierro usando char como reductor

    Directory of Open Access Journals (Sweden)

    Yenny Rubiela Hernández, Carlos Alberto Sandoval Fonseca, Claudia Inés Sánchez Buitrago

    2011-05-01

    Full Text Available Muestra los ensayos de  reduciblidad  realizados en un hornotipo Linder a un mineral de hierro del municipio de Ubalá(departamento de Cundinamarca, Colombia, usando comoreductor un char. Se  indican las características del mineralde  hierro  de Ubalá, de  los  carbones  empleados para  laproducción del char y de la caliza, así como los ensayos dereducibilidad. Para la caracterización de  las materias primasy del char, como producto  final, se aplicaron normas ASTM.En  la producción de  los char se utilizaron  los hornos decoquización  tipo Cerchar  y  tipo  colmena  de  la Uptc  enSamacá  (Boyacá. Los ensayos de reducibilidad se hicieronbajo  los mismos parámetros de operación utilizados concarbón como reductor, y los resultados obtenidos dejan verque el mineral de hierro de Ubalá es reducible en menorporcentaje con char. Sin embargo, por  los grandes beneficiospara el medioambiente que se obtienen trabajando con elchar, no se descarta  la posibilidad de utilizarlo como posiblesustituto del carbón en el proceso de reducción directa.

  6. Bitumen on Water: Charred Hay as a PFD (Petroleum Flotation Device

    Directory of Open Access Journals (Sweden)

    Nusrat Jahan

    2015-10-01

    Full Text Available Global demand for petroleum keeps increasing while traditional supplies decline. One alternative to the use of conventional crude oils is the utilization of Canadian bitumen. Raw bitumen is a dense, viscous, semi-liquid that is diluted with lighter crude oil to permit its transport through pipelines to terminals where it can then be shipped to global markets. When spilled, it naturally weathers to its original form and becomes dense enough to sink in aquatic systems. This severely limits oil spill recovery and remediation options. Here we report on the application of charred hay as a method for modifying the surface behavior of bitumen in aquatic environments. Waste or surplus hay is abundant in North America. Its surface can easily be modified through charring and/or chemical treatment. We have characterized the modified and charred hay using solid-state NMR, contact angle measurements and infrared spectroscopy. Tests of these materials to treat spilled bitumen in model aquatic systems have been undertaken. Our results indicate that bitumen spills on water will retain their buoyancy for longer periods after treatment with charred hay, or charred hay coated with calcium oxide, improving recovery options.

  7. Study of bio-oil and bio-char production from algae by slow pyrolysis

    International Nuclear Information System (INIS)

    This study examined bio-oil and bio-char fuel produced from Spirulina Sp. by slow pyrolysis. A thermogravimetric analyser (TGA) was used to investigate the pyrolytic characteristics and essential components of algae. It was found that the temperature for the maximum degradation, 322 °C, is lower than that of other biomass. With our fixed-bed reactor, 125 g of dried Spirulina Sp. algae was fed under a nitrogen atmosphere until the temperature reached a set temperature between 450 and 600 °C. It was found that the suitable temperature to obtain bio-char and bio-oil were at approximately 500 and 550 °C respectively. The bio-oil components were identified by a gas chromatography/mass spectrometry (GC–MS). The saturated functional carbon of the bio-oil was in a range of heavy naphtha, kerosene and diesel oil. The energy consumption ratio (ECR) of bio-oil and bio-char was calculated, and the net energy output was positive. The ECR had an average value of 0.49. -- Highlights: •Bio-oil and bio-char fuel produced from Spirulina Sp. by slow pyrolysis. •Suitable temperature to obtained bio-oil and bio-char were at about 550 and 500 °C. •Saturated functional carbon of bio-oil was heavy naphtha, kerosene, diesel oil. •ECR had an average value of 0.49

  8. Gasification of bio char from empty fruit bunch in a fluidized bed

    International Nuclear Information System (INIS)

    Full text: Bio char from empty fruit bunch was gasified in a fluidized bed reactor using compressed air as a gasifying agent. The experiment was conducted in the temperature ranges of 500-850 degree Celsius and the equivalence ratio, temperature and size of the feedstock was varied. A series of parameters such as gas yield, overall carbon conversion, gas quality, and composition, were measured as a function of temperature, equivalence ratio and temperature. Results obtained were compared to the actual values of coal and other gasification feedstock reveal that, bio char has the potential to replace coal as a gasification agent in power plants .Hydrogen gas from bio char was also optimized during the experiment. There is great potential of making Hydrogen from Bio char through thermo chemical gasification It was observed that it has a very great potential of being upgraded to Fischer Tropsh fuels. There is a great opportunity of using this char from empty fruit bunch as an alternative fuel in power plants and all the adverse effects of coal gasification can be counteracted. (author)

  9. Competitive biodegradation of dichlobenil and atrazine coexisting in soil amended with a char and citrate

    International Nuclear Information System (INIS)

    The role of char nutrients in the biodegradation of coexisting dichlobenil and atrazine in a soil by their respective bacterial degraders, DDN and ADP, was evaluated. Under growing conditions, their degradation in soil extract was slow with <40% and <20% degraded within 64 h, respectively. The degradation in extracts and slurries of char-amended solids increased with increasing char content, due to nutritional stimulation on microbial activities. By supplementing soil extract with various major nutrients, the measured degradation demonstrated that P was the exclusive limiting nutrient. The reduction in the degradation of coexisting dichlobenil and atrazine resulted apparently from the competitive utilization of P by DDN and ADP. With a shorter lag phase, ADP commenced growing earlier than DDN with the advantage of utilizing P first in insufficient supply. This resulted in an inhibition on the growth of DDN and thus suppression on dichlobenil degradation. - Competitive utilization of char nutrients by bacterial degraders resulted in the preferential biodegradation of atrazine over dichlobenil in a soil containing a wheat-straw-derived char.

  10. Effects of Hybrid Fibre Reinforcement on Fire Resistance Performance and Char Morphology of Intumescent Coating

    Directory of Open Access Journals (Sweden)

    Amir N.

    2016-01-01

    Full Text Available Recent researches of fire retardant intumescent coatings reinforced by single Rockwool and single glass wool fibre at various weight percentages and lengths showed some improvements to the mechanical properties of the coatings and the char produced. Therefore, in this research the fibres were combined together in intumescent coating formulation at several weight percentages and fibre lengths to study their effects towards fire resistance performance and char morphology. The hybrid fibre reinforced intumescent coatings were subjected to two types of fire tests; Bunsen burner at 1000°C and the electric furnace at 800°C for 1 hour, respectively. Steel temperature of the coated samples during Bunsen burner test was recorded to determine the fire resistance performance. Thermal stability of the intumescent coatings and chars was determined by Thermogravimetric Analysis (TGA. The morphology of the coatings and char was then examined by using Scanning Electron Microscopy (SEM and Energy Dispersive Spectrometry (EDS was conducted to obtain elemental composition of the samples. This research concluded that long-hybrid fibre at 12-mm length and 0.6% fibre-weight produced the top performing hybrid fibre intumescent formulation. The hybrid fibres form survived at elevated temperature, hence helped to provide structure and strengthen the char with the highest fire resistance was recorded at steel temperature of 197°C.

  11. Adsorption characteristics of SO{sub 2}, NO by steam activated biomass chars

    Energy Technology Data Exchange (ETDEWEB)

    Lu, Fei; Shu, Tong; Wang, Kuan; Lu, Ping [Nanjing Normal Univ. (China). School of Energy and Mechanical Engineering

    2013-07-01

    Wheat straw and rice husk collected from the suburb of Nanjing, China, were prepared to different kinds of steam activated biomass-based chars, and the adsorption characteristics of the biomass-based chars was carried out in a fixed bed reactor. The specific surface area and pore structure of different biomass chars were measured by nitrogen adsorption-desorption analysis instrument at 77K. The effects of biomass type, pyrolysis temperature, heating rate, activation temperature and concentration of SO{sub 2}, NO on the adsorption efficiency of SO{sub 2}, NO were analyzed. The results indicated that the steam activation has significant effects on the specific surface area, total pore volume and micro-morphology of biomass chars by improving the internal structure. The adsorption efficiency of SO{sub 2}, NO increased with the decreasing of SO{sub 2}, NO concentration in the experimental range. The optimal condition of char preparation (873K, fast pyrolysis) and steam activation (1,073K) was proposed based on the adsorption efficiency and adsorption volume of SO{sub 2}, NO. It builds a theoretical basis for industrial applications of biomass.

  12. Effect of bone char application on Pb bioavailability in a Pb-contaminated soil

    International Nuclear Information System (INIS)

    The effects of bone char (BC) application on the bioavailability of Pb in a polluted soil from Hunan Province, China were examined. The Pb-contaminated soil was treated with two types of bone char, one from the UK and the other from China. The bioavailability of Pb was determined in terms of the uptake by Chinese cabbage (Brassica chinensis L.), sequential extraction and X-ray diffraction analysis. The results indicate that the Pb concentrations in both shoots and roots decreased with increasing quantities of added bone char, and the application of BC from the UK at the rate of 1.6% (w:w) had the largest effect. Lead Pb concentrations in the shoots and roots decreased by 56.0% and 75.9%, respectively, whereas the application of BC from Zhejiang Province, China at the rate of 1.6% (w:w) reduced Pb concentrations in the shoots and roots to 2.04 mg kg-1 and 8.42 mg kg-1, respectively, only 45.8% and 30.2% compared to the control treatment. Sequential extraction results indicate that the addition of bone char, as a metal-immobilizing agent, substantially transforms soil Pb from non-residual fractions to the residual fraction. The transformation was further confirmed using X-ray diffraction studies. - Bone char amendments show potential for remediation of Pb-contaminated soils

  13. Development of carbon dioxide adsorbent from rice husk char

    Science.gov (United States)

    Abang, S.; Janaun, J.; Anisuzzaman, S. M.; Ikhwan, F. S.

    2016-06-01

    This study was mainly concerned about the development of carbon dioxide (CO2) adsorbent from rice husk (RH). Several chemical treatments were used to produce activated rice husk char (RHAC) from RH. Initially the RH was refluxed with 3M of sodium hydroxide (NaOH) solution, activation followed by using 0.5M of zinc chloride (ZnCl2) solution and finally acidic treatment by using 0.1M of hydrochloric acid (HCl). Then, the RHAC was functionalized by using 3-chloropropylamine hydrochloride (3-CPA) and noted as RHN. RHN samples were characterized with scanning electron microscopy (SEM), mercury intrusion porosimetry (MIP), fourier transform infrared spectroscopy (FTIR). Based on the SEM, the RHN sample had a large pore diameter compared to RH sample after being treated. Based on MIP data, the average pore diameter between RH and RHAC samples were increased significantly from 0.928 microns to 1.017 microns. The RHN sample also had higher total porosity (%) compared to RHAC and RH (58.45%, 47.82% and 45.57% respectively). The total specific surface area of the sample was much increasing from RHO to RHAC (29.17 m2/g and 62.94 m2/g respectively) and slightly being decreasing from RHAC to RHN (58.88 m2/g). FTIR result showed the present of weak band at 1587 cm-1 which demonstrating of the amine group present on the sample. The CO2 capture result showed that the decreasing of operating temperature can increase the breakthrough time of CO2 capture. On the contrary decreasing of CO2 gas flow rate can increase the breakthrough time of CO2 capture. The highest total amount of CO2 adsorbed was 25338.57 mg of CO2/g of RHN sample by using 100 mL/min of gas flow rate at 30oC. Based on adsorption isotherm analysis, the Freundlich isotherm was the best isotherm to describe the CO2 adsorption on the sample.

  14. Development and Verification of the Charring Ablating Thermal Protection Implicit System Solver

    Science.gov (United States)

    Amar, Adam J.; Calvert, Nathan D.; Kirk, Benjamin S.

    2010-01-01

    The development and verification of the Charring Ablating Thermal Protection Implicit System Solver is presented. This work concentrates on the derivation and verification of the stationary grid terms in the equations that govern three-dimensional heat and mass transfer for charring thermal protection systems including pyrolysis gas flow through the porous char layer. The governing equations are discretized according to the Galerkin finite element method with first and second order implicit time integrators. The governing equations are fully coupled and are solved in parallel via Newton's method, while the fully implicit linear system is solved with the Generalized Minimal Residual method. Verification results from exact solutions and the Method of Manufactured Solutions are presented to show spatial and temporal orders of accuracy as well as nonlinear convergence rates.

  15. The use of activated char for flue gas polishing in municipal and hazardous waste combustors

    Energy Technology Data Exchange (ETDEWEB)

    Hartenstein, H.U. [L & C Steinmueller GmbH, Gummersbach (Germany)

    1996-12-31

    During the late 1980`s and the early 1990`s legislation on emissions from waste combustors were tightened drastically. Also emission limits on new pollutants like dioxins and furans were introduced. Since the flue gas cleaning equipment commonly used before was not designed to meet these emission limits, new technologies had to be developed. Most of these new technologies rely on the use of activated carbon or char for the adsorption of the pollutants. Due to the fact that the amount of activated char used is directly proportional to the mass flow rate of pollutants entering the adsorber, the bulk part of the pollutants has been removed in the preceding gas cleaning stages. Thus the activated char adsorption reactor is employed as a flue gas polishing stage at the end of the APC-train.

  16. Mound Laboratory activities on the removal of plutonium and uranium from wastewater using bone char

    Energy Technology Data Exchange (ETDEWEB)

    Blane, D.W.; Murphy, E.L.

    1976-09-30

    Pilot plant studies sponsored by the Division of Military Application (DMA) to treat Mound Laboratory's low risk waste streams with bone char columns have been completed. This project was to accomplish the following: (1) acquire engineering data such as flow rates, adsorption capacity, and optimum particle size for designing a tertiary treatment system, and (2) optimize the primary waste treatment process using coagulants and flocculants. Bone char, a natural product made from granulated cattle bone, is a form of calcium hydroxyapatite (Ca/sub 10/(PO/sub 4/)/sub 6/(OH)/sub 2/) and contains a small amount of carbon. It is characterized by a high porosity and good resistance to abrasion and crushing. Because plutonium and other actinides can be precipitated as phosphates from weakly acidic, neutral or alkaline solutions, it appeared possible to use an insoluble phosphate adsorbent such as bone char to remove them from waste streams.

  17. Fuel gas and char from pyrolysis of waste paper in a microwave plasma reactor

    Directory of Open Access Journals (Sweden)

    Parin Khongkrapan, Patipat Thanompongchart, Nakorn Tippayawong, Tanongkiat Kiatsiriroat

    2013-01-01

    Full Text Available In this study, a microwave plasma reactor was used for pyrolysis of waste papers. The effects of different argon flow rates on char and gas generation were investigated. Changes in carbon and oxygen contents from those in paper to char were significant. Char yield of over 25 % was obtained with the heating value of about 38 MJ/kg. Average gas yield and total content of combustible fraction (CO, CH4 and H2 in the gas product were 2.56 m3/kg and 36 %, respectively. The heating value of gas product and carbon conversion efficiency of the process were maximum at 6.0 MJ/m3 and 73 %, respectively.

  18. A simple expression for the apparent reaction rate of large wood char gasification with steam.

    Science.gov (United States)

    Umeki, Kentaro; Roh, Seon-Ah; Min, Tai-Jin; Namioka, Tomoaki; Yoshikawa, Kunio

    2010-06-01

    A simple expression for the apparent reaction rate of large wood char gasification with steam is proposed. Large char samples were gasified under steam atmosphere using a thermo-balance reactor. The apparent reaction rate was expressed as the product of the intrinsic rate and the effective factor. The effective factor was modified to include the effect of change in char diameter and intrinsic reaction rate during the reaction. Assuming uniform conversion ratio throughout a particle, the simplified reaction scheme was divided into three stages. In the initial stage, the local conversion ratio increases without particle shrinkage. In the middle stage, the particle shrinks following the shrinking core model without change in the local conversion ratio. In the final stage, the local conversion ratio increases without particle shrinkage. The validity of the modified effective value was confirmed by comparison with experimental results. PMID:20144863

  19. Adsorption of Pb(II by Activated Pyrolytic Char from Used Tire

    Directory of Open Access Journals (Sweden)

    Lu Ping

    2016-01-01

    Full Text Available As a renewable resource, the pyrolytic char derived from used tire has promising adsorption capacities owing to its similar structure and properties with active carbon. The purification and activation of the pyrolytic char from used tire, as well as the application of this material in the adsorption of Pb(II in water is conducted. The influences on the adsorption capacity by temperature and pH value are investigated and discussed; the adsorption thermodynamics and kinetics are also studied. The results show that the pyrolytic char from used tire has remarkable adsorption capacity for Pb(II, and the adsorption is an endothermic process complying with the Langmuir isotherm. The adsorption kinetics is a pseudo second-order reaction.

  20. A solid state NMR investigation of char forming processes in polymer degradation

    CERN Document Server

    Dick, C M

    2002-01-01

    A detailed knowledge of the condensed phase chemistry occurring in polymers exposed to elevated temperatures is crucial to understanding the behaviour of polymers exposed to fire. This is particularly true when trying to reduce polymer flammability by means of promoting char-forming reactions. Until recently, however, structural information on highly crosslinked chars and their precursors has been difficult to obtain, and as a consequence many degradation workers have merely labelled degradation residues as 'intractable'. However, the application of solid state NMR techniques developed in our laboratories for the structural characterisation of coals has provided a considerable insight into the structure and chemistry of polymer chars formed under both oxidative and non-oxidative conditions. A series of polymers including poly(vinyl chloride), poly(vinyl acetate), polyurethanes, polychloropene, cis and trans polyisoprene have been studied. These polymers have been used to describe the application of quantitati...

  1. Production of Bio char with High Mineral Content from Oil Palm Biomass

    International Nuclear Information System (INIS)

    Carbonization of oil palm empty fruit bunch (OPEFB) biomass for the production of high mineral content bio char under an uncontrolled carbonization temperature and controlled air flow rate was studied using a pilot-scale brick carbonization reactor. The maximum temperature during the carbonization process was found to be in the range of 543 to 564 degree Celsius at exhaust gas flow rate of 36 m3/ hr. All minerals (for example P, K ,Mg, Ca, Na, Mn, Fe, Cr, AI) showed an increased from the feedstock concentration up to 300 %. The concentration of heavy metal extracted from OPEFB bio char was lower than listed ceiling permitted levels. This proposed system without electrical control and heating source is preferable to the industry due to its simplicity, ease of operation and low energy requirement making it suitable for OPEFB bio char production for mulching purposes with more than double the mineral content compared to raw OPEFB biomass. (author)

  2. Fuel gas and char from pyrolysis of waste paper in a microwave plasma reactor

    Energy Technology Data Exchange (ETDEWEB)

    Khongkrapan, Parin; Thanompongchart, Patipat; Tippayawong, Nakorn; Kiatsiriroat, Tanongkiat [Department of Mechanical Engineering, Faculty of Engineering, Chiang Mai University, Chiang Mai 50200 (Thailand)

    2013-07-01

    In this study, a microwave plasma reactor was used for pyrolysis of waste papers. The effects of different argon flow rates on char and gas generation were investigated. Changes in carbon and oxygen contents from those in paper to char were significant. Char yield of over 25 % was obtained with the heating value of about 38 MJ/kg. Average gas yield and total content of combustible fraction (CO, CH4 and H2) in the gas product were 2.56 m3/kg and 36 %, respectively. The heating value of gas product and carbon conversion efficiency of the process were maximum at 6.0 MJ/m3 and 73 %, respectively.

  3. Slow pyrolysis of nutshells: characterization of derived chars and of process kinetics

    Energy Technology Data Exchange (ETDEWEB)

    Bonelli, P.R. [Universidad de Buenos Aires (Argentina). Dpto. de Industrias

    2003-08-01

    Char samples were obtained from slow pyrolysis of hazelnut and peanut shells at different temperatures (623 K, 873 K, and 1123 K). Composition, heating values, and surface properties of the charcoals were analyzed to explore their potentiality as bio-fuels and/or for further conversion into activated carbons. The chars generated from both wastes at 873 K exhibited good properties for these purposes, although the hazelnut shell-derived char showed a relatively greater potential. Furthermore, kinetics of the shell's pyrolysis over the temperature range 300 to 1200 K was characterized from nonisothermal thermogravimetric measurements by applying a model that assumes a steadily increasing variation in the activation energy with the process course. It allowed for a satisfactory description of kinetic data for the pyrolysis of hazelnut and peanut shells over the whole range of temperatures examined. Differences in the estimated kinetic parameters characterizing the wastes were found. (author)

  4. Sulfur retention by ash during coal combustion. Part I. A model of char particle combustion

    Directory of Open Access Journals (Sweden)

    BORISLAV GRUBOR

    2003-02-01

    Full Text Available A model for the combustion of porous char particles as a basis for modeling the process of sulfur retention by ash during coal combustion is developed in this paper. The model belongs to the microscopic intrinsic models and describes the dynamic behavior of a porous char particle during comustion, taking into account temporal and spatial changes of all important physical properties of the char particle and various combustion parameters. The parametric analysis of the enhanced model shows that the model represents a good basis for the development of a model for the process of sulfur retention by ash during coal combustion. The model enables the prediction of the values of all parameters necessary for the introduction of reactions between sulfur compounds and mineral components in ash, primarily calcium oxide.

  5. Preparation of effective lignite chars for SO{sub 2} adsorption

    Energy Technology Data Exchange (ETDEWEB)

    Zimny, T.; Finqueneisel, G.; Weber, J.V. [Metz Univ. (France). Lab. de Chimi Industrielle; Izquierdo, M.T. [Departemento Energia y Medio Ambiente, Zaragoza (Spain). Inst. de Carboquimica

    1999-12-01

    The objective of this work was to determine the efficiency of activated chars produced from two different lignites to remove sulfur dioxide from industrial flue gas. The lignites used differ mainly in their ashes and water contents. The chars were produced at semi-pilot scale (0.5 t) in rotary kiln, and in our optimized conditions of temperature, the specific surface reaches 372 m{sup 2}/g (pyrolysis temperature 800 C) for the best char. In order to investigate the effect of surface oxigenated groups, a simple and mild post-oxidation treatment (40 min at 320 C in air) was performed. The dynamic adsorption of SO{sub 2} was realized at 100 C in controlled atmosphere containing O{sub 2}, H{sub 2}O, SO{sub 2} and N{sub 2} as a balance. In these conditions 70 mg SO{sub 2}/g can be adsorbed by the best sample. After six adsorption/desorption cycles for the best char, the decrease of adsorption capacity is close to 20%. The oxidation of the char surface leads to a sensible decrease of its adsorption capacity. This could be explained by a simultaneous increase of the basic surface groups which should enhanced SO{sub 2} adsorption and acidic groups which seem to be involved in the deactivation process. The influence of lignite pre-drying (before pyrolysis) on adsorption behavior of char is limited. Finally, once more, the lack of relation between surface area and SO{sub 2} adsorption capacity is observed. That means that considering polar and acidic molecules, both porosity and surface chemistry play important role. (orig.)

  6. Production and Characterization of Bio-Char from the Pyrolysis of Empty Fruit Bunches

    OpenAIRE

    Mohamad A. Sukiran; Loh S. Kheang; Nasrin A. Bakar; Choo Y. May

    2011-01-01

    Problem statement: The palm oil industry generates an abundance of oil palm biomass such as the Empty Fruit Bunch (EFB), shell, frond, trunk and Palm Oil Mill Effluent (POME). For 88 million tones of Fresh Fruit Bunch (FFB) processed in 2008, the amount of oil palm biomass was more than 26 million tones. Studies about production of bio-char from oil palm biomass are still lacking in Malaysia. So, this study was aimed to: (i) determine the effect of pyrolysis temperatures on bio-char yield (ii...

  7. Porous structure and morphology of granular chars from flash and conventional pyrolysis of grape seeds

    International Nuclear Information System (INIS)

    This work studies the influence of the operating conditions used in the pyrolysis of grape seeds on the morphology and textural properties of the chars resulting. Flash and conventional (283 K min−1 heating rate) pyrolysis have been used within a wide range of temperature (300–1000 °C). The effect of a pretreatment for oil extraction has also been studied. The porous structure of the chars was characterized by adsorption of N2 at 77 K, Ar at 77 K and 87 K, and CO2 at 273 K and mercury intrusion porosimetry. The morphology was analyzed by scanning electron microscopy. All the materials prepared revealed an essentially microporous structure, with a poor or even negligible contribution of mesopores. Increasing pyrolysis temperature led to higher specific surface areas and lower pore size. The highest specific surface area values occurred within 700–800 °C, reaching up to 500 m2 g−1 with pore sizes in the 0.4–1.1 nm range. No significant morphological changes were observed upon carbonization so that the resulting chars were granular materials of similar size than the starting grape seeds. The hollow core structure of the chars, with most of the material allocated at the periphery of the granules can help to overcome the mass transfer limitations of most common (solid or massive) granular activated carbons. The chars showed a good mechanical strength during attrition tests. These chars can be potential candidates for the preparation of granular carbons molecular sieve or activated carbons raw materials. -- Highlights: •We use a raw material that has a very low price and a high availability. •Not very much attention has been paid to this waste for carbonaceous materials preparation. •The chars obtained have high specific surface area that is an interesting starting point for later activation processes. •The chars show a micro-macro porous bimodal distribution. •Pyrolysis does not affect to morphology or initial seed, leading a carbonized particles

  8. Differences in physical properties and CO{sub 2} gasification reactivity between coal char and petroleum coke

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Y.Q.; Wu, S.Y.; Gu, J.; Gao, J.S. [East China University of Science & Technology, Shanghai (China)

    2009-09-15

    This paper mainly investigated the physical properties and gasification reactivity of coal char and petroleum coke, separately at the high temperature pyrolysis (950-1400{sup o}C) with slow heating rate and pyrolysis pressure of the atmospheric pressure and at the pressurized pyrolysis (the atmospheric pressure to 3 MPa) with rapid heating rate and the pyrolysis temperature of 950{sup o}C. Some significant differences in those between coal chars and petroleum coke were found. The high temperature pyrolysis caused more easily the graphitization of petroleum coke than that of coal char, especially in the higher temperature range. The increasing pyrolysis temperature resulted in the decrease of surface areas of coal char and the increase of surface areas of petroleum coke. As the pyrolysis pressure was elevated from the atmospheric pressure to 3 MPa, surface areas of petroleum coke initially increased and then decreased, while those of coal chars presented an opposite tendency. The increasing pyrolysis temperature was adverse to the gasification activity of coal chars and was favorable for the gasification activity of petroleum coke. Also, the effects of the pyrolysis pressure on the gasification activity of coal char and petroleum coke were significantly different. The gasification activity of petroleum coke was obviously lower than that of coal chars, and even lower than that of the natural graphite.

  9. Intrinsic reactivity of biomass-derived char under steam gasification conditions. Potential of wood ash as catalyst.

    NARCIS (Netherlands)

    Nanou, Pavlina; Gutierrez Murillo, Hector E.; Swaaij, van Wim P.M.; Rossum, van Guus; Kersten, Sascha R.A.

    2013-01-01

    The influence of ash on the steam gasification rate of pine wood derived char particles in the temperature range 600–800 °C is investigated. Ash derived from pine wood or specific ash components were added to the pine-wood (before pyrolysis) or to the produced char (after pyrolysis) via physical mix

  10. Reactivity of young chars via energetic distribution measurements. Final report, 1 September 1990--31 December 1994

    Energy Technology Data Exchange (ETDEWEB)

    Calo, J.M.; Zhang, L.; Lu, W.; Lilly, W.D.

    1996-01-01

    We have developed what we believe to be the very first, a priori, correlation/prediction technique for the gasification reactivity of coal char. With this method the gasification reactivity of a coal char as a function of temperature can be correlated using the data from a temperature programmed desorption (TPD) experiment following gasification under conditions where the reactivity is controlled by the thermal desorption of oxygen surface complexes formed during gasification. The current project was directed at extending and developing related techniques for the characterization and prediction/correlation of the reactivity of the ``young`` chars to CO{sub 2} and steam. Of particular interest was mapping of the reactivity behavior of the resultant chars, as revealed by the energetic heterogeneity of the complexes with char preparation conditions.

  11. Kinetic models for the oxy-fuel combustion of coal and coal/biomass blend chars obtained in N2 and CO2 atmospheres

    International Nuclear Information System (INIS)

    The thermal reactivity and kinetics of five coal chars, a biomass char, and two coal/biomass char blends in an oxy-fuel combustion atmosphere (30%O2–70%CO2) were studied using the non-isothermal thermogravimetric method at three heating rates. Fuel chars were obtained by devolatilization in an entrained flow reactor at 1273 K under N2 and CO2 atmospheres. Three nth-order representative gas–solid models – the volumetric model (VM), the grain model (GM) and the random pore model (RPM) – were employed to describe the reactive behaviour of the chars. The RPM model was found to be the best for describing the reactivity of the high rank coal chars, while VM was the model that best described the reactivity of the bituminous coal chars, the biomass char and the coal-biomass blend char. The kinetic parameters of the chars obtained in N2 and CO2 in an oxy-fuel combustion atmosphere with 30% of oxygen were compared, but no relevant differences were observed. The behaviour of the blend of the bituminous coal (90%wt.) and the biomass (10%wt.) chars resembled that of the individual coal concealing the effect of the biomass. Likewise, no interaction was detected between the high rank coal and the biomass chars during oxy-fuel combustion of the blend. -- Highlights: ► Oxy-fuel reactivity and kinetics of coal and coal/biomass blends chars were determined. ► Kinetic parameters were essentially the same under N2 or CO2 devolatilization atmospheres. ► Best model for describing chars reactivity depended on the parent coal rank. ► Random pore model for low rank coal and biomass chars; volumetric model for high rank coal chars.

  12. Experiments of char particle segregation effect on the gas conversion behavior in the fuel reactor for chemical looping combustion

    International Nuclear Information System (INIS)

    Highlights: • This work verified the existence of char particle segregation in the fuel reactor during CLC. • The char particle segregation has detrimental effect on the conversion of the char gasification product CO. • Larger/heavier char particles located near the reactor bottom have a higher CO conversion than the smaller/lighter char. • Larger fluidizing gas velocity can reduce the effect of char segregation on CO conversion. • Oxygen carriers of high reactivity can convert CO completely although segregation effect exists. - Abstract: In solid fuel (such as lignite) chemical looping combustion, solid fuels undergo pyrolysis and gasification. The volatiles from pyrolysis and the gasification product (CO/H2) react with oxygen carriers. The gas conversion (to CO2/H2O) in the fuel reactor is a key point. However, char particles of different sizes and conversion ratios cause segregation in the fuel reactor, which influences the contact time between fuel gases and the carrier, thereby changing the gas conversion behavior. In order to gain information on obtaining a high gas conversion in the fuel reactor, this work focused on the effect of the char particle segregation on gas conversion. Different factors – the char particle size, the fluidizing gas velocity, and the oxygen carrier reactivity – were taken into account. Smaller char particles with low density would float on top of the fluidized bed, corresponding to a low gas conversion (mf in the Fe63Al bed) can reduce the segregation effect, resulting in a higher CO conversion. High reactivity carriers can convert CO completely although segregation exists, whereas low reactivity carriers exhibit the segregation effect and thus corresponds to a low CO conversion

  13. Role of char during reburning of nitrogen oxides. First quarterly report, October 1, 1993--December 31, 1993

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Wei-Yin

    1993-12-31

    Customarily, coal and lignite have not been considered viable reburning fuels for a number of reasons. NO reduction through homogeneous gas phase mechanisms is generally believed more important than the heterogeneous NO reduction on char; and coal devolatilization in the fuel rich environment generates only about 50% of the volatile hydrocarbon radicals than gaseous hydrocarbons under the same fuel-to-oxidant stoichiometry. In addition, the fuel nitrogen could result in additional nitrogen oxide emissions in the burnout stage. What has not been anticipated is the highly active nature of lignite char surface. First, it has been demonstrated in the literature that lignite char can be gasified by nitrogen oxide; second, the minerals in lignite char can catalyze the CO + NO and gasification reaction; and third, lignite char has a highly porous structure which is desirable for gas/solid reactions. The unique NO activity on char surface is expected to benefit the utilities which are involved in coal combustion and have to meet the stringent Clean Air Act Amendments of 1990. This program is aimed at a better understanding of the chemical and physical mechanisms involved in the reburning with chars. Char gasification rates will be measured with and without the presence of CO. Further, the rate of the char catalyzed CO + NO reaction will also be measured. Experiments have been conducted with a flow reactor which simulates the reburning stage. One bituminous coal and two lignites, one from North Dakota and the other from Mississippi, are used in these tasks. A unique component of this program is the use of the fractal concept in the estimations of these gas/solid reaction rates. The proposed program is designed to investigate the relative importance of these two reactions (char gasification and ash catalyzed CO + NO reactions) under reburning conditions.

  14. Spatial and temporal trends of mercury and other metals in landlocked char from lakes in the Canadian Arctic archipelago

    International Nuclear Information System (INIS)

    Spatial and temporal trends of mercury (Hg) and 22 other elements were examined in landlocked Arctic char (Salvelinus alpinus) from six lakes in the Canadian Arctic (Char, Resolute and North Lakes, and Amituk Lake on Cornwallis Island, Sapphire Lake on Devon Island and Boomerang Lake on Somerset Island). The objectives of the study were to compare recent concentrations of Hg and other metals in char with older data from Amituk, Resolute and Char Lakes, in order to examine temporal trends as well as to investigate factors influencing spatial trends in contaminant levels such as lake characteristics, trophic position, size and age of the fish. Geometric mean Hg concentrations in dorsal muscle ranged from 0.147 μg/g wet weight (ww) in Resolute Lake to 1.52 μg/g ww in Amituk Lake for samples collected over the period 1999-2003. Char from Amituk Lake also had significantly higher selenium (Se). Mercury in char from Resolute Lake was strongly correlated with fish length, weight, and age, as well as with thallium, lead and Se. In 5 of 6 lakes, Hg concentrations were correlated with stable nitrogen isotope ratios (δ 15N) and larger char were feeding at a higher trophic level presumably due to feeding on smaller char. Weight adjusted mean Hg concentrations in char from Amituk Lake, and unadjusted geometric means in Char Lake and Resolute Lakes, did not show any statistically significant increase from the early 1990s to 2003. However, small sample sizes from 1999-2003 for fish 15N values best explained the higher concentrations of Hg in Amituk Lake compared to the other lakes

  15. The influence of fine char particles burnout on bed agglomeration during the fluidized bed combustion of a biomass fuel

    Energy Technology Data Exchange (ETDEWEB)

    Scala, Fabrizio; Chirone, Riccardo [Istituto di Ricerche sulla Combustione, CNR, P.le V. Tecchio, 80-80125 Naples (Italy); Salatino, Piero [Dipartimento di Ingegneria Chimica, Universita degli Studi di Napoli Federico II, P.le V. Tecchio, 80-80125 Naples (Italy)

    2003-11-15

    The combustion of biomass char in a bubbling fluidized bed is hereby addressed, with specific reference to the influence that the combustion of fine char particles may exert on ash deposition and bed agglomeration phenomena. Experiments of steady fluidized bed combustion (FBC) of powdered biomass were carried out with the aim of mimicking the postcombustion of attrited char fines generated in the fluidized bed combustion of coarse char. Experimental results showed that the char elutriation rate is much smaller than expected on the basis of the average size of the biomass powder and of the carbon loading in the combustor. Samples of bed material collected after prolonged operation of the combustor were characterized by scanning electron microscopy (SEM)-EDX analysis and revealed the formation of relatively coarse sand-ash-carbon aggregates. The phenomenology is consistent with the establishment of a char phase attached to the bed material as a consequence of adhesion of char fines onto the sand particles. Combustion under sound-assisted fluidization conditions was also tested. As expected, enhancement of fines adhesion on bed material and further reduction of the elutriation rate were observed. Experimental results are interpreted in the light of a simple model which accounts for elutriation of free fines, adhesion of free fines onto bed material and detachment of attached fines by attrition of char-sand aggregates. Combustion of both free and attached char fines is considered. The parameters of the model are assessed on the basis of the measured carbon loadings and elutriation rates. Model computations are directed to estimate the effective size and the peak temperature of char-sand aggregates. The theoretical estimates of the effective aggregate size match fairly well those observed in the experiments.

  16. An investigation of the reactivity of chars formed in fluidized-bed gasifiers: equipment development and initial tests

    Energy Technology Data Exchange (ETDEWEB)

    A. Cousins; N. Paterson; D.R. Dugwell; R. Kandiyoti [Imperial College London, London (United Kingdom). Department of Chemical Engineering

    2006-03-15

    Chars formed during air and oxygen blown gasification processes have a low reactivity. This is due to changes that occur in the structure and morphology of the original coal during heating. In part, the changes depend on conditions prevailing during the pyrolysis stage and partly on the length of time spent at peak temperature. Previous work in this laboratory has highlighted that the gasification reactivity of a char depends on the conditions of its formation. This means that chars must be prepared under realistic conditions when conducting laboratory scale reactivity studies that are intended to support a larger scale development. This is not easy to do and requires the development of dedicated methods for preparing the char. In this paper, the development of a laboratory-scale test, based on a laboratory-scale spouted bed gasifier, is described that is able to prepare chars under conditions that represent those in an air-blown gasifier. The reactivity of the prepared chars is then examined to identify how the reactivity of the char varies within the envisaged operating window of the process. A feature of this apparatus is that the char formation time is known accurately, which has required the development of novel feeding and draining mechanisms. These enable the coal particles to be injected quickly into the reactor and the sand/char bed drained and quenched rapidly after a known residence time. The extent of char deactivation can be measured with residence times between 2 and 3600 s. In this paper, the validation of the experiment is described and some preliminary results are reported. 7 refs., 10 figs., 2 tabs.

  17. The thermal history of char as disclosed by carbon isotope ratios

    DEFF Research Database (Denmark)

    Egsgaard, Helge; Ambus, Per; Ahrenfeldt, Jesper;

    pyrolysis and isotope ratio mass spectrometry. The results demonstrate that the temperature history of the char is reflected in the fine variation of carbon isotopes. The compound classes responsible for the variation were identified. Key words: Isotope ratio, flash pyrolysis, hot gas cleaning...

  18. CharToon 2.1 extensions : expression repertoire and lip sync

    NARCIS (Netherlands)

    Ruttkay, Z.M.; Lelièvre, A.D.F.

    2000-01-01

    CharToon is a modular system to design and animate 21/2D faces and other graphic al objects. This report contains the extensions made for version 2.1, effecting only the Animation Editor module. The new features allow the re-usage of a reper toire of expression snapshots and animations and automatic

  19. Gasification of disordered carbons (chars). Annual Progress Report for Period August 1, 1979-October 31, 1980

    Energy Technology Data Exchange (ETDEWEB)

    Walker, P.L. Jr.; Jenkins, R.G.

    1980-06-01

    It has been shown that rates of gasification of chars derived from coals vary widely with the rank of coal and the gasification medium used. Variation in rates is thought to be attributable to: (i) variation in active surface area and (ii) extent to which gasification is catalyzed by inorganic impurities present. It is the main objective of this research to confirm this hypothesis for carbons of different morphologies, including disordered carbons (chars). Initially studies are being performed on the carbon-oxygen reaction. This report covers progress in research in three areas: (i) measurement of rate constants for the adsorption step in the reaction of O/sub 2/ with a high purity char at low pressures, (ii) design and construction of a high pressure reactor to be used to measure rate constants for the desorption step in the reaction of O/sub 2/ with carbons, and (iii) development of small angle x-ray scattering (SAXS) to characterize both dispersion of catalysts supported on carbon and the micropore system of chars.

  20. Investigation of non-isothermal and isothermal gasification process of coal char using different kinetic model

    Institute of Scientific and Technical Information of China (English)

    Wang Guangwei; Zhang Jianliang; Shao Jiugang; Li Kejiang; Zuo Haibin

    2015-01-01

    Isothermal and non-isothermal gasification kinetics of coal char were investigated by using thermogravi-metric analysis (TGA) in CO2 atmosphere, and the experimental data were interpreted with the aids of random pore model (RPM), unreacted shrinking core model (URCM) and volume model (VM). With the increase of heating rate, gasification curve moves into high temperature zone and peak rate of gasification increases;with the increase of gasification temperature, gasification rate increases and the total time of gasification is shortened. The increase of both heating rate and gasification temperature could improve gasification process of coal char. Kinetics analysis indicates that experimental data agree better with the RPM than with the other two models. The apparent activation energy of non-isothermal and isother-mal gasification of coal char using RPM is 193.9 kJ/mol and 212.6 kJ/mol respectively, which are in accor-dance with reported data. Gasification process of coal char under different heating rates and different temperatures are predicted by the RPM derived in this study, and it is found that the RPM predicts the reaction process satisfactorily.

  1. Char-amended farm soils – effects on soil chemistry and wheat growth

    Science.gov (United States)

    On-farm gasification of agricultural residues, the non-food byproducts from crop harvests, could provide a means to generate value-added income from the production of fuel or electrical generation. Char produced during the process also has potential value as a soil amendment to adjust acid soil pH (...

  2. Quantitative Analysis of Graphene Sheet Content in Wood Char Powders during Catalytic Pyrolysis

    Institute of Scientific and Technical Information of China (English)

    Yan-Jia Liou; Wu-Jang Huang

    2013-01-01

    The quantitative characterization of the graphene sheet content in carbon-containing materials is arguable and has not yet been developed.The authors report on a feasible method to characterize graphene sheet content quantitatively in pyrolized carbon materials using an X-ray diffraction (XRD) spectrometer.A direct carbonation at 300 ℃ followed by catalytic pyrolysis (heat-treatment temperature was set at 700-1400 ℃)under a vacuum condition was used for turning wood waste into pyrolized wood char powders.The graphene content in the samples was calculated through an analysis of full width at half maximum (FWHM) of the carbon (100) crystal plane at around 42°-43° in XRD.Results showed that the FWHM and the calculated graphene sheet content of pyrolized wood char powders depended on the heat-treatment temperature,and the FWHM of wood char powder with well-developed graphene sheets (100%) was determined to be 5.0.In addition,the trend to 100% graphene sheet-contained pyrolized carbon powder was obtained at a heattreatment temperature of 2700 ℃.The resistivity of the wood char powder with 100% graphene sheets was predicted to be 0.01 Ω cm,close to our experimental data of 0.012 and 0.006 Ω cm for commercial graphite and graphene products,respectively.

  3. MOLECULAR TRACERS FOR SMOKE FROM CHARRING/BURNING OF CHITIN BIOPOLYMER. (R823990)

    Science.gov (United States)

    AbstractMonosaccharide derivatives from the breakdown of cellulose are the major organic components of smoke particles emitted to the atmosphere from biomass burning. In urban areas a related biopolymer, chitin, may contribute markers to smoke from grilling/charring o...

  4. Carbon distribution in char residue from gasification of kraft black liquor

    International Nuclear Information System (INIS)

    The char residue yields and the total carbon and carbonate content were measured for dry black liquor solids after pyrolysis or gasification in a laminar entrained-flow reactor. The experimental conditions were 700-1000 deg. C in N2,CO2/N2 or water vapor/N2 at 1 bar total pressure, for residence times from 0.3 to 1.7 s. Fixed carbon yields, when measured at the same particle residence time, decreased with increasing reactor temperature. CO2 and water vapor diminished the char carbon significantly at temperatures above 800 deg. C, compared with pyrolysis in N2. Water vapor oxidized the char carbon more rapidly than did CO2. At 1000 deg. C, the reactions of carbon with sulfate and carbonate became faster, resulting in a smaller difference between carbon conversion rates in the different gas environments. By the end of devolatilization, the amount of carbonate in the char had changed very little at 700-800 deg. C. After devolatilization, carbonate was formed more rapidly at higher temperatures. The presence of CO2 or water vapor increased the formation of carbonate. In the presence of these gases, more carbonate was measured at all temperatures and residence times. The maximum carbonate measured in the char was 16% of the carbon in the black liquor solids, as compared to 4.4% in the original dry liquor solids. Under most conditions, the carbonate, as a fraction of carbon input, first increased to a constant, temperature-independent value and then decreased

  5. Mixed waste treatment using the ChemChar thermolytic detoxification technique

    International Nuclear Information System (INIS)

    The diversity of mixed waste matrices contained at Department of Energy sites that require treatment preclude a single, universal treatment technology capable of handling sludges, solids, heterogeneous debris, aqueous and organic liquids and soils. Versatility of the treatment technology, volume reduction and containment of the radioactive component of the mixed waste streams are three criteria to be considered when evaluating potential treatment technologies. The ChemChar thermolytic detoxification process being developed under this R and D contract is a thermal, chemically reductive technology that converts the organic portion of a mixed waste stream to an energy-rich synthesis gas while simultaneously absorbing volatile inorganic species (metals and acid gases) on a macroporous, carbon-based char. The latter is mixed with the waste stream prior to entering the reactor. Substoichiometric amounts of oxidant are fed into the top portion of the cylindrical reactor generating a thin, radial thermochemical reaction zone. This zone generates all the necessary heat to promote the highly endothermic reduction of the organic components in the waste in the lower portion of the reactor, producing, principally, hydrogen and carbon monoxide. The solid by-product is a regenerated carbon char that, depending on the inorganic loading, is capable for reuse. The in situ scrubbing of contaminants by the char within the reactor coupled with a char filter for final polishing produce an exceptionally clean synthesis gas effluent suitable for on-site generation of heat, steam or electricity. Despite the elevated temperatures in the thermochemical reaction zone, the reductive nature of the process precludes formation of nitrogen oxides and halogenated organic compound by-products

  6. Preparation of mulberry branch biomass char and its usage in wastewater treatment.

    Science.gov (United States)

    Wu, Dong Lei; Wang, Wei; Zhang, Jing Hui; Fu, Hao; Lv, Xiao Shu; Xu, Xin Hua

    2012-11-01

    Biomass char was prepared from mulberry branches by physical activation. An examination by Fourier transform infrared spectroscopy (FTIR) indicated that the functional groups of Si-O were mostly burnt out, significantly decreasing the ash content Analysis of data from a scanning electron microscope (SEM) and a Brunauer-Emmett-Teller (BET) test also revealed increased surface roughness and pore structure, which improved the adsorption capacity of biomass char after preparation. The optimum conditions for preparation were found to be pyrolysis at 700 degrees C for 30 minutes, and then activation at 750 degrees C for one hour, with 3.4% steam content for the activating agent. The prepared biomass char was then employed to adsorb ammonium, copper(II) actetate [Cu(II)] and hexavalent chromium [Cr(VI)] in a solution. The results indicated that the prepared biomass char had a better adsorptive performance than the raw material. Moreover, the removal of determinands increased along with the dosage, and the highest adsorption efficiency of ammonium, copper(II) acetate [Cu(II)] and hexavalent chromium [Cr(VI)] were found to be 20%, 100% and 50%, respectively. The adsorptions of ammonium and hexavalent chromium [Cr(VI)] can be simulated by a pseudo-second order model, while the adsorption of copper(II) acetate [Cu(II)] is better simulated by a pseudo-first order model. The adsorption isotherms of copper(II) acetate [Cu(II)] by biomass char were also investigated, and the Langmuir isotherm was found to best describe the adsorption process. PMID:23356022

  7. Synthesis of palm oil empty fruit bunch magnetic pyrolytic char impregnating with FeCl3 by microwave heating technique

    International Nuclear Information System (INIS)

    Empty fruit bunch (EFB) is one of the most abundant residues of the Palm oil mill industry in Malaysia. The novel magnetic bio-char was synthesized by single stage microwave heating technique, using EFB in the presence of ferric chloride hexahydrate. The effect of microwave powers, radiation time and impregnation ratio (IR) of ferric chloride hexahydrate to biomass were studied. Also the process parameters such as microwave powers, radiation times and IR were optimized using response surface method. The statistical analysis revealed that the optimum conditions for the high porosity magnetic bio-char production were at 900 W microwave power, 20 min radiation time and 0.5 (FeCl3: biomass) impregnation ratio. These newly produced magnetic bio-char have a high surface area of 890 m2 g−1 and that leads to highly efficient in the removal of methylene blue (MB) with an efficiency of 99.9% from aqueous solution with a maximum adsorption capacity of 265 mg g−1. - Highlights: • Magnetic bio-char production using discarded material EFB with chemical activation. • Single stage synthesis of magnetic bioc-har via microwave heating was narrated. • Effect of each process parameters on synthesis of magnetic bio-char was elaborated. • Magnetic bio-char has high surface area, high porosity and high adsorption capacity. • Novel magnetic bio-char adds new dimension to the materials as an adsorbent

  8. Micro-PIXE analysis of strontium in Arctic char, Salvelinus alpinus, otoliths from Quttinirpaaq National Park, Nunavut, Canada

    International Nuclear Information System (INIS)

    Arctic char, Salvelinus alpinus, exhibit either lake resident or anadromous (sea-run) life histories. Anadromy is less prevalent at the northern and southern extremes of the distribution. Effective conservation and management of char requires knowledge of life histories exhibited by individuals and populations. Micro-PIXE line-scans were used to determine the distribution of strontium (Sr) in otoliths from which life history patterns were determined for Arctic char from 10 lakes in Quttinirpaaq National Park in the Canadian High Arctic. Although most populations were lake resident as expected, the data indicated that a component of the char population from one lake was anadromous. This represents the most northerly known char population to exhibit anadromy. Mean Sr concentrations in otoliths of char from all populations, as determined by point analysis and also from line-scan data, showed no significant differences between the methods. Mean Sr concentrations (from point analysis) showed significant differences between some of the populations. These differences combined with other analyses (e.g. morphometrics, genetics) can be used to differentiate biological populations. Thus, micro-PIXE analysis is a useful tool for assessing diversity in Arctic char and contributing to their management and conservation in the park

  9. Characterization of char derived from various types of solid wastes from the standpoint of fuel recovery and pretreatment before landfilling

    International Nuclear Information System (INIS)

    Carbonization is a kind of pyrolysis process to produce char from organic materials under an inert atmosphere. In this work, chars derived from various solid wastes were characterized from the standpoint of fuel recovery and pretreatment of waste before landfilling. Sixteen kinds of municipal and industrial solid wastes such as residential combustible wastes, non-combustible wastes, bulky wastes, construction and demolition wastes, auto shredder residue, and sludges were carbonized at 500 deg. C for 1 h under nitrogen atmosphere. In order to evaluate the quality of char as fuel, proximate analysis and heating value were examined. The composition of raw waste had a significant influence on the quality of produced char. The higher the ratio of woody biomass in waste, the higher heating value of char produced. Moreover, an equation to estimate heating value of char was developed by using the weight fraction of fixed carbon and volatile matter in char. De-ashing and chlorine removal were performed to improve the quality of char. The pulverization and sieving method seems to be effective for separation of incombustibles such as metal rather than ash. Most char met a 0.5 wt% chlorine criterion for utilization as fuel in a shaft blast furnace after it was subjected to repeated water-washing. Carbonization could remove a considerable amount of organic matter from raw waste. In addition, the leaching of heavy metals such as chrome, cadmium, and lead appears to be significantly suppressed by carbonization regardless of the type of raw waste. From these results, carbonization could be considered as a pretreatment method for waste before landfilling, as well as for fuel recovery

  10. Mechanism of corrosion of structural materials in contact with coal chars in coal gasifier atmospheres. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Douglass, D.L.; Bhide, V.S.; Vineberg, E.

    1980-05-01

    Six alloys, 310 stainless steel, Hastelloy X, Inconel 671, Incoloy 800, Haynes 188, and FeCrAlY (GE1541 and MA956), were corroded in two chars at 1600 and 1800/sup 0/F. The chars, FMC and Husky, contained 2.7 and 0.9% sulfur, respectively. Various parameters were investigated, including char size, cover gas, char quantity, char replenishment period, gas composition, and the use of coatings. The corrosion process was strictly sulfidation when the char was replenished every 24 hours or less. The kinetics of reaction were nearly linear with time. The reaction resulted in thick external sulfide scales with extensive internal sulfidation in the substrate. The kinetics and reaction-product morphologies suggested that diffusion through the sulfide scale played a minor role and that an interfacial reaction was the rate-controlling step. A mathematical model was developed which supported this hypothesis. The reaction rates showed a relatively minor role on alloy composition, depending upon whether the alloys were tested singularly or in combination with others. Inconel 671, the best alloy in CGA environments, consistently corroded the most rapidly of the chromia-former types regardless of char sulfur content or of the temperature. Type 310 stainless was marginally better than Inconel 671. Incoloy 800 was intermediate, whereas, Haynes 188 and Hastelloy X exhibited the best corrosion resistance. The FeCrAlY alloys reacted very rapidly in the absence of preoxidation treatments. All alloys corroded in char at least 1000 times more rapidly than in the CGA (MPC-ITTRI) environment. None of the alloys will be acceptable for use in contact with char unless coatings are applied.

  11. Impact of charring on cereal grain characteristics: linking prehistoric manuring practice to 15N signatures in archaeobotanical material

    DEFF Research Database (Denmark)

    Kanstrup, Marie; Thomsen, Ingrid Kaag; Mikkelsen, Peter Hambro; Christensen, Bent Tolstrup

    2012-01-01

    . However, despite attempts to deliberately tamper and distort the grain δ15N signature, the changes observed in this study were too small to be of any consequences for the archaeobotanical applicability of the method. Thus the isotope method offers unique evidence about prehistoric manuring practice....... information about prehistoric manuring practice. Prehistoric grains are generally found in a charred state of which the exact charring conditions are unknown but most likely often multifarious. In this study we examined the influence of grain weight and a range of charring conditions with regards duration...

  12. CHAR CRYSTALLINE TRANSFORMATIONS DURING COAL COMBUSTION AND THEIR IMPLICATIONS FOR CARBON BURNOUT

    Energy Technology Data Exchange (ETDEWEB)

    ROBERT H. HURT

    1998-09-08

    Recent work at Sandia National Laboratories, Imperial College, and the U.K. utility PowerGen, has identified an important mechanism believed to have a large influence on unburned carbon levels from pulverized coal-fired boilers. That mechanism is char carbon crystalline rearrangements on subsecond times scales at temperatures of 1800 - 2500 K, which lead to char deactivation in the flame zones of furnaces. The so-called thermal annealing of carbons is a well known phenomenon, but its key role in carbon burnout has only recently been appreciated, and there is a lack of quantitative data in this time/temperature range. In addition, a new fundamental tool has recently become available to study crystalline transformations, namely high resolution transmission electron microscopy (HRTEM) fringe imaging, which provides a wealth of information on the nature and degree of crystallinity in carbon materials such as coal chars. Motivated by these new developments, this University Coal Research project has been initiated with the following two goals:  to determine transient, high-temperature, thermal deactivation kinetics as a function of parent coal and temperature history.  to characterize the effect of this thermal treatment on carbon crystalline structure through high-resolution transmission electron microscopy and specialized, quantitative image analysis. Work is currently underway on the following three tasks: Task 1 Experimental technique development. The goal of this task is to develop and demonstrate an apparatus and procedure for measuring transient, high-temperature, thermal deactivation of coal chars. While peak gas temperatures in boilers are often in the range 1800 - 2000 K, peak particle temperatures can be much higher due to high rates of heat release at the particle surface due to exothermic carbon oxidation. The prototype transient heat treatment apparatus is based on an inert-gas purged graphite-rod sample holder that is subjected to rapid Joule heating to

  13. Determination of the forms of calcium present in coal chars by Ca K-edge XANES with Synchrotron Radiation

    CERN Document Server

    Liu, Lijuan; Cui, Mingqi; Hu, Yongfeng; Zheng, Lei; Zhao, Yidong; Ma, Chenyan; Xi, Shibo; Yang, Dongliang; Guo, Zhiying; Wang, Jie

    2012-01-01

    This work is concerned with the Ca transformations during the pyrolysis of Ca(OH)2 or CaCO3-added coals. Ca K-edge X-ray absorption near edge structure (XANES) spectroscopy was applied to determine the forms of Ca in chars prepared from the pyrolysis of Ca-added coal. Results showed that Ca(OH)2 and CaSO4 existed in both the Ca(OH)2-added chars and the CaCO3-added chars, while CaS and CaO only existed in the chars prepared from the Ca(OH)2-added coal. Moreover, it was found that carboxyl Ca was formed during pyrolysis for either the Ca(OH)2-added coal or the CaCO3-added coals.

  14. Upgrading the rice husk char obtained by flash pyrolysis for the production of amorphous silica and high quality activated carbon.

    Science.gov (United States)

    Alvarez, Jon; Lopez, Gartzen; Amutio, Maider; Bilbao, Javier; Olazar, Martin

    2014-10-01

    The overall valorization of rice husk char obtained by flash pyrolysis in a conical spouted bed reactor (CSBR) has been studied in a two-step process. Thus, silica has been recovered in a first step and the remaining carbon material has been subjected to steam activation. The char samples used in this study have been obtained by continuous flash pyrolysis in a conical spouted bed reactor at 500°C. Extraction with Na2CO3 allows recovering 88% of the silica contained in the rice husk char. Activation of the silica-free rice husk char has been carried out in a fixed bed reactor at 800°C using steam as activating agent. The porous structure of the activated carbons produced includes a combination of micropores and mesopores, with a BET surface area of up to 1365m(2)g(-1) at the end of 15min. PMID:25127010

  15. Characterization of adsorption of aqueous arsenite and arsenate onto charred dolomite in microcolumn systems.

    Science.gov (United States)

    Salameh, Yousef; Al-Muhtaseb, Ala'a H; Mousa, Hasan; Walker, Gavin M; Ahmad, Mohammad N M

    2014-01-01

    In this work, the removal of arsenite, As(III), and arsenate, As(V), from aqueous solutions onto thermally processed dolomite (charred dolomite) via microcolumn was evaluated. The effects of mass of adsorbent (0.5-2 g), initial arsenic concentration (50-2000 ppb) and particle size (dolomite in a microcolumn were investigated. It was found that the adsorption of As(V) and As(III) onto charred dolomite exhibited a characteristic 'S' shape. The adsorption capacity increased as the initial arsenic concentration increased. A slow decrease in the column adsorption capacity was noted as the particle size increased from>0.335 to 0.710-2.00 mm. For the binary system, the experimental data show that the adsorption of As(V) and As(III) was independent of both ions in solution. The experimental data obtained from the adsorption process were successfully correlated with the Thomas Model and Bed Depth Service Time Model. PMID:25244130

  16. Hydrogen Production From Crude Bio-oil and Biomass Char by Electrochemical Catalytic Reforming

    Institute of Scientific and Technical Information of China (English)

    Xing-long Li; Shen Ning; Li-xia Yuan; Quan-xin Li

    2011-01-01

    We reports an efficient approach for production of hydrogen from crude bio-oil and biomass char in the dual fixed-bed system by using the electrochemical catalytic reforming method.The maximal absolute hydrogen yield reached 110.9 g H2/kg dry biomass.The product gas was a mixed gas containing 72%H2,26%CO2,1.9%CO,and a trace amount of CH4.It was observed that adding biomass char (a by-product of pyrolysis of biomass) could remarkably increase the absolute H2 yield (about 20%-50%).The higher reforming temperature could enhance the steam reforming reaction of organic compounds in crude bio-oil and the reaction of CO and H2O.In addition,the CuZn-Al2O3 catalyst in the water-gas shift bed could also increase the absolute H2 yield via shifting CO to CO2.

  17. Production of Low-Phosphorus Molten Iron from High-Phosphorus Oolitic Hematite Using Biomass Char

    Science.gov (United States)

    Tang, Huiqing; Qi, Tengfei; Qin, Yanqi

    2015-09-01

    In this study, an energy-saving and environmentally friendly method to produce low-phosphorus molten iron from high-phosphorus oolitic hematite was experimentally investigated and theoretically analyzed. The results indicate that biomass char is a suitable reducing agent for the proposed method. In the direct reduction stage, the ore-char briquette reached a metallization degree of 80-82% and a residual carbon content of 0.1-0.3 mass%. Under the optimized condition, phosphorus remained in the gangue as calcium phosphate. In the melting separation stage, phosphorus content ([%P]) in molten iron could be controlled by introducing a Na2CO3 additive, and the phosphorus behavior could be predicted using ion molecular coexistence theory. Molten iron with [%P] less than 0.3 mass% was obtained from the metallic briquettes with the aforementioned quality by introducing 2-4% Na2CO3 and the iron recovery rate was 75-78%.

  18. Simultaneous determination of devolatilization and char burnout times during fluidized bed combustion of coal

    International Nuclear Information System (INIS)

    In this paper, the authors investigate a method for simultaneous determination of devolatilization and char burnout times based on the analysis of CO2 emissions from a fluidized bed combustor. The technique is not-intrusive and can be performed under realistic combustion conditions. The authors' method involves batching single-sized coal sample sin a fluidized bed combustor that is heated with propane gas or other fuel. Carbon dioxide profiles versus time for the batch tests are analyzed with a linear model to obtain characteristic time constants for coal devolatilization and char combustion which can be related to total devolatilization time and burnout time for a coal sample. The authors' approach does not require special sample preparation, can be performed in actual combustion equipment, and employs standard boiler instrumentation

  19. Simultaneous determination of devolatilization and char burnout times during fluidized bed combustion of coal

    International Nuclear Information System (INIS)

    In this paper, the authors investigate a method for simultaneous determination of devolatilization and char burnout times based on the analysis of CO2 emissions from a fluidized bed combustor. The technique is non-intrusive and can be performed under realistic combustion conditions. The authors' method involves batching single-size coal samples in a fluidized bed combustor that is heated with propane gas or other fuel. Carbon dioxide profiles versus time for the batch tests are analyzed with a linear model to obtain characteristic time constants for coal devolatilization and char combustion which can be related to total devolatilization time and burnout time for a coal sample. The authors' approach does not require special sample preparation, can be performed in actual combustion equipment and employs standard boiler instrumentation

  20. Characterization of char derived from various types of solid wastes from the standpoint of fuel recovery and pretreatment before landfilling

    OpenAIRE

    Hwang, I. H.; Matsuto, T.; Tanaka, N; Sasaki, Y; Tanaami, K.

    2007-01-01

    Carbonization is a kind of pyrolysis process to produce char from organic materials under an inert atmosphere. In this work, chars derived from various solid wastes were characterized from the standpoint of fuel recovery and pretreatment of waste before landfilling. Sixteen kinds of municipal and industrial solid wastes such as residential combustible wastes, non-combustible wastes, bulky wastes, construction and demolition wastes, auto shredder residue, and sludges were carbonized at 500℃ fo...

  1. Modeling and evaluation of chromium remediation from water using low cost bio-char, a green adsorbent

    International Nuclear Information System (INIS)

    Oak wood and oak bark chars were obtained from fast pyrolysis in an auger reactor at 400-450 deg. C. These chars were characterized and utilized for Cr(VI) remediation from water. Batch sorption studies were performed at different temperatures, pH values and solid to liquid ratios. Maximum chromium was removed at pH 2.0. A kinetic study yielded an optimum equilibrium time of 48 h with an adsorbent dose of 10 g/L. Sorption studies were conducted over a concentration range of 1-100 mg/L. Cr(VI) removal increased with an increase in temperature (QOakwoodo: 25 deg. C = 3.03 mg/g; 35 deg. C = 4.08 mg/g; 45 deg. C = 4.93 mg/g and QOakbarko: 25 deg. C = 4.62 mg/g; 35 deg. C = 7.43 mg/g; 45 deg. C = 7.51 mg/g). More chromium was removed with oak bark than oak wood. The char performances were evaluated using the Freundlich, Langmuir, Redlich-Peterson, Toth, Radke and Sips adsorption isotherm models. The Sips adsorption isotherm model best fits the experimental data [high regression (R2) coefficients]. The overall kinetic data was satisfactorily explained by a pseudo second order rate expression. Water penetrated into the char walls exposing Cr(VI) to additional adsorption sites that were not on the surfaces of dry char pores. It is remarkable that oak chars (SBET: 1-3 m2 g-1) can remove similar amounts of Cr(VI) as activated carbon (SBET: ∼1000 m2 g-1). Thus, byproduct chars from bio-oil production might be used as inexpensive adsorbents for water purification. Char samples were successfully used for chromium remediation from contaminated surface water with dissolved interfering ions.

  2. Effects of fresh and aged chars from pyrolysis and hydrothermal carbonization on nutrient sorption in agricultural soils

    Science.gov (United States)

    Gronwald, M.; Don, A.; Tiemeyer, B.; Helfrich, M.

    2015-06-01

    Leaching of nutrients from agricultural soils causes major environmental problems that may be reduced with amendments of chars derived from pyrolysis (pyrochars) or hydrothermal carbonization (hydrochars). Chars are characterized by a high adsorption capacity - i.e. they may retain nutrients such as nitrate and ammonium. However, the physicochemical properties of the chars and hence their sorption capacity likely depend on feedstock and the production process. We investigated the nutrient retention capacity of pyrochars and hydrochars from three different feedstocks (digestates, Miscanthus, woodchips) mixed into different soil substrates (sandy loam and silty loam). Moreover, we investigated the influence of char degradation on its nutrient retention capacity using a 7-month in situ field incubation of pyrochar and hydrochar mixed into soils at three different field sites. Pyrochars showed the highest ability to retain nitrate, ammonium and phosphate, with pyrochar from woodchips being particularly efficient in nitrate adsorption. Ammonium adsorption of pyrochars was controlled by the soil type of the soil-char mixture. We found some ammonium retention on sandy soils, but no pyrochar effect or even ammonium leaching from the loamy soil. The phosphate retention capacity of pyrochars strongly depended on the pyrochar feedstock with large phosphate leaching from digestate-derived pyrochar and some adsorption capacity from woodchip-derived pyrochar. Application of hydrochars to agricultural soils caused small, and often not significant, effects on nutrient retention. In contrast, some hydrochars did increase the leaching of nutrients compared to the non-amended control soil. We found a surprisingly rapid loss of the chars' adsorption capacity after field application of the chars. For all sites and for hydrochar and pyrochar, the adsorption capacity was reduced by 60-80 % to less or no nitrate and ammonium adsorption. Thus, our results cast doubt on the efficiency of

  3. Bone char surface modification by nano-gold coating for elemental mercury vapor removal

    International Nuclear Information System (INIS)

    Highlights: • A novel nanocomposite including bone char and gold nanoparticle was developed for capture of Hg0 vapor. • EDS and XRD results confirm the presence of nano-gold on the surface of the bone char support. • The majority of the pores were found to be in the mesoporous range. • The dynamic capacity of 586 μg/g was obtained for Hg0 vapor. - Abstract: The present work was done to develop a novel nanocomposite using bone char coated with nano-gold for capture of elemental mercury (Hg0) from air. The morphologies, structures, and chemical constitute of the prepared nanocomposite were evaluated by UV–VIS–NIR, dynamic light-scattering (DLS), X-ray diffraction (XRD), transmission electron microscopy (TEM), Fourier transform infra-red (FTIR) spectroscopy, and energy dispersive X-ray spectroscopy (EDS). The capture performance of nanocomposite was evaluated in a needle trap for mercury vapor. An on-line setup based on cold vapor atomic absorption spectrometry (CVAAS) was designed for Hg0 determination. Dynamic capacity of nanocomposite for Hg0 was shown high efficient operating capacity of 586.7 μg/g. As temperature increases, the dynamic adsorption capacity of the nanocomposite was decreased, which are characteristics of physicosorption processes. It was found that the surface modification of bone char with nano-gold has various advantages such as high operating dynamic adsorption capacity and low cost preparation. It was also demonstrated that the developed nanocomposite is suitable for on-line monitoring of Hg0. It could be applied for the laboratory and field studies

  4. Structural Analysis of Char by Raman Spectroscopy: Improving Band Assignments through Computational Calculations from First Principles

    Energy Technology Data Exchange (ETDEWEB)

    Smith, Matthew W.; Dallmeyer, Ian; Johnson, Timothy J.; Brauer, Carolyn S.; McEwen, Jean-Sabin; Espinal, Juan F.; Garcia-Perez, Manuel

    2016-04-01

    Raman spectroscopy is a powerful tool for the characterization of many carbon 27 species. The complex heterogeneous nature of chars and activated carbons has confounded 28 complete analysis due to the additional shoulders observed on the D-band and high intensity 29 valley between the D and G-bands. In this paper the effects of various vacancy and substitution 30 defects have been systematically analyzed via molecular modeling using density functional 31 theory (DFT) and how this is manifested in the calculated gas-phase Raman spectra. The 32 accuracy of these calculations was validated by comparison with (solid-phase) experimental 33 spectra, with a small correction factor being applied to improve the accuracy of frequency 34 predictions. The spectroscopic effects on the char species are best understood in terms of a 35 reduced symmetry as compared to a “parent” coronene molecule. Based upon the simulation 36 results, the shoulder observed in chars near 1200 cm-1 has been assigned to the totally symmetric 37 A1g vibrations of various small polyaromatic hydrocarbons (PAH) as well as those containing 38 rings of seven or more carbons. Intensity between 1400 cm-1 and 1450 cm-1 is assigned to A1g 39 type vibrations present in small PAHs and especially those containing cyclopentane rings. 40 Finally, band intensity between 1500 cm-1 and 1550 cm-1 is ascribed to predominately E2g 41 vibrational modes in strained PAH systems. A total of ten potential bands have been assigned 42 between 1000 cm-1 and 1800 cm-1. These fitting parameters have been used to deconvolute a 43 thermoseries of cellulose chars produced by pyrolysis at 300-700 °C. The results of the 44 deconvolution show consistent growth of PAH clusters with temperature, development of non-45 benzyl rings as temperature increases and loss of oxygenated features between 400 °C and 46 600 °C

  5. Determination of reactivity parameters of model carbons, cokes and flame-chars

    DEFF Research Database (Denmark)

    Sørensen, Lasse Holst; Gjernes, Erik; Jessen, Thomas; Fjellerup, Jan

    1996-01-01

    Reactivity profiles are defined and measured with thermogravimetry for a dense metallurgical Longyear coke, a polymer-derived porous active carbon, Carboxen 1000, and three flame-chars, Illinois #6, Pittsburgh #8 and New Mexico Blue #1. For each sample it is found that the reactivity profile can ...... reactivity measure is used to rank fuels with very different structural profiles, at varying levels of burnout, temperature and oxygen partial pressure. Keyword: TGA,Reactivity,Coal...

  6. Fixed-bed adsorption study of methylene blue onto pyrolytic tire char

    Science.gov (United States)

    Makrigianni, Vassiliki; Giannakas, Aris; Papadaki, Maria; Albanis, Triantafyllos; Konstantinou, Ioannis

    2016-04-01

    In this work, the adsorption efficiency of acid treated pyrolytic tire char to cationic methylene blue (MB) dye adsorption from aqueous solutions was investigated by fixed-bed adsorption column experiments. The effects of the initial dye concentration (10 - 40 mg L-1) and feed flow rate (50 - 150 mL min -1) with a fixed bed height (15 cm) were studied in order to determine the breakthrough characteristics of the adsorption system. The Adams-Bohart, Yoon-Nelson and Thomas model were applied to the adsorption of MB onto char at different operational conditions to predict the breakthrough curves and to determine the characteristic parameters of the column. The results showed that the maximum adsorbed quantities decreased with increasing flow rate and increased with increasing initial MB concentration. Breakthrough time and exhaustion time increased with decreasing inlet dye concentration and flow rate. In contrast with Adams-Bohart model, Yoon-Nelson model followed by Thomas model were found more suitable to describe the fixed-bed adsorption of methylene blue by char. The correlation coefficient values R2 for both models at different operating conditions are higher than 0.9 and the low average relative error values provided very good fittings of experimental data at different operating conditions. Higher adsorption capacity of 3.85 mg g -1 was obtained at 15 cm of adsorbent bed height, flow rate of 100 mL min -1and initial MB concentration of 40 mg L-1. Although that activated carbons exhibited higher adsorption capacities in the literature, acid-treated pyrolytic tire char was found to be considerably efficient adsorbent for the removal of MB dye column taking into account the advantages of the simpler production process compared to activated carbons, as well as, the availability of waste tire feedstock and concurrent waste tire management.

  7. A study of carbonaceous char oxidation in air by semi-quantitative FTIR spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Koch, A.; Krzton, A.; Finqueneisel, G.; Heintz, O.; Weber, J.-V.; Zimny, T. [IUT Saint-Avold (France). Departement Chimie

    1998-05-01

    The paper describes the methodology of semi-quantitative characterization of coal-derived carbonaceous material oxidized under mild thermal conditions. Infrared spectroscopic analysis was applied to the determination of chemical changes induced by oxidation. A curve fitting model has thus been developed to evidence the evolution of specific chemical groups during treatment. The possibility to follow mechanisms and kinetics of carbonaceous char oxidation through data obtained by this model has been demonstrated. 28 refs., 7 figs., 2 tabs.

  8. Bone char surface modification by nano-gold coating for elemental mercury vapor removal

    Energy Technology Data Exchange (ETDEWEB)

    Assari, Mohamad javad [Department of Environmental & Occupational Health, Faculty of Medical Sciences, Tarbiat Modares university, Tehran (Iran, Islamic Republic of); Rezaee, Abbas, E-mail: rezaee@modares.ac.ir [Department of Environmental & Occupational Health, Faculty of Medical Sciences, Tarbiat Modares university, Tehran (Iran, Islamic Republic of); Rangkooy, Hossinali [Occupational Health Department, Faculty of Health, Jondishapor Medical Sciences University, Ahvaz (Iran, Islamic Republic of)

    2015-07-01

    Highlights: • A novel nanocomposite including bone char and gold nanoparticle was developed for capture of Hg{sup 0} vapor. • EDS and XRD results confirm the presence of nano-gold on the surface of the bone char support. • The majority of the pores were found to be in the mesoporous range. • The dynamic capacity of 586 μg/g was obtained for Hg{sup 0} vapor. - Abstract: The present work was done to develop a novel nanocomposite using bone char coated with nano-gold for capture of elemental mercury (Hg{sup 0}) from air. The morphologies, structures, and chemical constitute of the prepared nanocomposite were evaluated by UV–VIS–NIR, dynamic light-scattering (DLS), X-ray diffraction (XRD), transmission electron microscopy (TEM), Fourier transform infra-red (FTIR) spectroscopy, and energy dispersive X-ray spectroscopy (EDS). The capture performance of nanocomposite was evaluated in a needle trap for mercury vapor. An on-line setup based on cold vapor atomic absorption spectrometry (CVAAS) was designed for Hg{sup 0} determination. Dynamic capacity of nanocomposite for Hg{sup 0} was shown high efficient operating capacity of 586.7 μg/g. As temperature increases, the dynamic adsorption capacity of the nanocomposite was decreased, which are characteristics of physicosorption processes. It was found that the surface modification of bone char with nano-gold has various advantages such as high operating dynamic adsorption capacity and low cost preparation. It was also demonstrated that the developed nanocomposite is suitable for on-line monitoring of Hg{sup 0}. It could be applied for the laboratory and field studies.

  9. Mixed Waste Treatment Using the ChemChar Thermolytic Detoxification Technique

    International Nuclear Information System (INIS)

    This R and D program addresses the treatment of mixed waste employing the ChemChar Thermolytic Detoxification process. Surrogate mixed waste streams will be treated in a four inch diameter, continuous feed, adiabatic reactor with the goal of meeting all regulatory treatment levels for the contaminants in the surrogates with the concomitant production of contaminant free by-products. Successful completion of this program will show that organic contaminants in mixed waste surrogates will be converted to a clean, energy rich synthesis gas capable of being used, without further processing, for power or heat generation. The inorganic components in the surrogates will be found to be adsorbed on a macroporous coal char activated carbon substrate which is mixed with the waste prior to treatment. These contaminants include radioactive metal surrogate species, RCRA hazardous metals and any acid gases formed during the treatment process. The program has three main tasks that will be performed to meet the above objectives. The first task is the design and construction of the four inch reactor at Mirage Systems in Sunnyvale, CA. The second task is production and procurement of the activated carbon char employed in the ChemChartest runs and identification of two surrogate mixed wastes. The last task is testing and operation of the reactor on char/surrogate waste mixtures to be performed at the University of Missouri. The deliverables for the project are a Design Review Report, Operational Test Plan, Topical Report and Final Report. This report contains only the results of the design and construction carbon production-surrogate waste identification tasks.Treatment of the surrogate mixed wastes has just begun and will not be reported in this version of the Final Report. The latter will be reported in the final version of the Final Report

  10. Mixed Waste Treatment Using the ChemChar Thermolytic Detoxification Technique

    Energy Technology Data Exchange (ETDEWEB)

    Kuchynka, D.J.

    1997-01-01

    This R and D program addresses the treatment of mixed waste employing the ChemChar Thermolytic Detoxification process. Surrogate mixed waste streams will be treated in a four inch diameter, continuous feed, adiabatic reactor with the goal of meeting all regulatory treatment levels for the contaminants in the surrogates with the concomitant production of contaminant free by-products. Successful completion of this program will show that organic contaminants in mixed waste surrogates will be converted to a clean, energy rich synthesis gas capable of being used, without further processing, for power or heat generation. The inorganic components in the surrogates will be found to be adsorbed on a macroporous coal char activated carbon substrate which is mixed with the waste prior to treatment. These contaminants include radioactive metal surrogate species, RCRA hazardous metals and any acid gases formed during the treatment process. The program has three main tasks that will be performed to meet the above objectives. The first task is the design and construction of the four inch reactor at Mirage Systems in Sunnyvale, CA. The second task is production and procurement of the activated carbon char employed in the ChemChartest runs and identification of two surrogate mixed wastes. The last task is testing and operation of the reactor on char/surrogate waste mixtures to be performed at the University of Missouri. The deliverables for the project are a Design Review Report, Operational Test Plan, Topical Report and Final Report. This report contains only the results of the design and construction carbon production-surrogate waste identification tasks.Treatment of the surrogate mixed wastes has just begun and will not be reported in this version of the Final Report. The latter will be reported in the final version of the Final Report.

  11. CO{sub 2} reforming of CH{sub 4} in coke oven gas to syngas over coal char catalyst

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, G.J.; Dong, Y.; Feng, M.R.; Zhang, Y.F.; Zhao, W.; Cao, H.C. [Taiyuan University of Technology, Taiyuan (China)

    2010-02-01

    The CO{sub 2} reforming of methane (in coke oven gas) on the coal char catalyst was performed in a fixed bed reactor at temperatures between 800 and 1200{sup o}C under normal pressure. The effects of the coal char catalyst pretreatment and the ratio of CO{sub 2}/CH{sub 4} were studied. Experimental results showed that the coal char was an effective catalyst for production of syngas, and addition of CO{sub 2} did not enhance the CH{sub 4} reforming to H{sub 2}. It was also found that the product gas ratio of H{sub 2}/CO is strongly influenced by the feed ratio of CO{sub 2}/CH{sub 4}. The modified coal char catalyst was more active during the CO{sub 2}-CH{sub 4} reforming than the coal char catalyst based on the catalyst volume, furthermore the modified catalyst exhibited high activity in CO{sub 2}-CH{sub 4} reforming to syngas. The conversion of methane can be divided into two stages. In the first stage, the conversion of CH{sub 4} gradually decreased. In the second stage, the conversion of methane maintained nearly constant. The conversion of CO{sub 2} decreased slightly during the overall reactions in CO{sub 2}-CH{sub 4} reforming. The coal char catalyst is a highly promising catalyst for the CO{sub 2} reforming of methane to syngas.

  12. Modeling char conversion under suspension fired conditions in O2/N2 and O2/CO2 atmospheres

    DEFF Research Database (Denmark)

    Brix, Jacob; Jensen, Peter Arendt; Jensen, Anker Degn

    2011-01-01

    The aim of this investigation has been to model combustion under suspension fired conditions in O2/N2 and O2/CO2 mixtures. Experiments used for model validation have been carried out in an electrically heated Entrained Flow Reactor (EFR) at temperatures between 1173 K and 1673 K with inlet O2 con...... conversion has been found. COCOMO does however suggest that CO2 gasification in oxy-fuel combustion at low O2 concentrations can account for as much as 70% of the overall char consumption rate during combustion in zone III.......The aim of this investigation has been to model combustion under suspension fired conditions in O2/N2 and O2/CO2 mixtures. Experiments used for model validation have been carried out in an electrically heated Entrained Flow Reactor (EFR) at temperatures between 1173 K and 1673 K with inlet O2...... concentrations between 5 and 28 vol.%. The COal COmbustion MOdel, COCOMO, includes the three char morphologies: cenospheric char, network char and dense char each divided between six discrete particle sizes. Both combustion and gasification with CO2 are accounted for and reaction rates include thermal char...

  13. Distribution of polycyclic aromatic hydrocarbons in fly ash during coal and residual char combustion in a pressurized fluidized bed

    Energy Technology Data Exchange (ETDEWEB)

    Hongcang Zhou; Baosheng Jin; Rui Xiao; Zhaoping Zhong; Yaji Huang [Nanjing University of Information Science and Technology, Nanjing (China)

    2009-04-15

    To investigate the distribution of polycyclic aromatic hydrocarbons (PAHs) in fly ash, the combustion of coal and residual char was performed in a pressurized spouted fluidized bed. After Soxhlet extraction and Kuderna-Danish (K-D) concentration, the contents of 16 PAHs recommended by the United States Environmental Protection Agency (U.S. EPA) in coal, residual char, and fly ash were analyzed by a high-performance liquid chromatography (HPLC) coupled with fluorescence and diode array detection. The experimental results show that the combustion efficiency is lower and the carbon content in fly ash is higher during coal pressurized combustion, compared to the residual char pressurized combustion at the pressure of 0.3 MPa. Under the same pressure, the PAH amounts in fly ash produced from residual char combustion are lower than that in fly ash produced from coal combustion. The total PAHs in fly ash produced from coal and residual char combustion are dominated by three- and four-ring PAHs. The amounts of PAHs in fly ash produced from residual char combustion increase and then decrease with the increase of pressure in a fluidized bed. 21 refs., 1 fig., 4 tabs.

  14. [Analysis on the target product from sewage sludge pyrolysis and experiments on using the char for enhancing plant cultivation].

    Science.gov (United States)

    Song, Xue-Ding; Chen, De-Zhen; Wang, Zhong-Hui; He, Wei

    2011-09-01

    Characteristics of sewage sludge pyrolysis under low temperatures were studied and the influences of reaction temperature and moisture content on products distribution and their properties were also investigated with a purpose to select a proper target product. After a dissective comparison, char produced from the pyrolysis process was chosen as the target product and then its effect on plant cultivation was checked by using it to plant garlic when blended into normal soil; also its heavy metals contents and their transfer to the garlic were investigated. The primary research results showed that with the moisture content reduced to a certain level, char production was above 40% of sewage sludge when the pyrolysis process took place under 550 degrees C; ash content of the char is around 60% - 65%, but it is rich with nitrogen, phosphorus and potassium contents. The heavy metal contents in the char meet up with the limitations for land use, and the garlic stems planted in the soil blended with the char grew much faster than those planted in normal soil with their averaged height being 3-4 cm higher; however the heavy metal contents in the fast-growing garlic stems were a little higher than that in the normal ones, which was not suitable for edible plants. The results obtained suggested that char produced from sewage sludge pyrolysis process could be a target product arranged for land use especially for non-edible plant cultivation. PMID:22165228

  15. Bio-oil and bio-char production from biomass and their structural analyses

    International Nuclear Information System (INIS)

    Energy demand is increasing day by day because of the rapid developments in the population, industrialization and urbanisation. Since, fossil fuels will be at the verge of getting extinct, researches are mostly focused on the renewable sources, such as biomass, in recent years. This paper provides an environmentally friendly process to convert waste biomass samples to bio-oil and bio-char by pyrolysis. For this purpose, pyrolysis characteristics of pomegranate peels under inert atmosphere were studied by using both TGA to analysis decomposition behaviour and a batch reactor to investigate product yields and properties. The properties of bio-oil and bio-char were investigated by different analytical techniques such as GC-MS, FT-IR, SEM, He pycnometry and elemental analysis. As a consequence, it is possible to obtain bio-oil, which has similar properties like petroleum hydrocarbons, and to obtain bio-char, which can be further used as a solid fuel or a carbonaceous adsorbent material via pyrolysis process. (full text)

  16. Characterization of red mud-epoxy intumescent char using surface imaging and micro analysis

    Energy Technology Data Exchange (ETDEWEB)

    Arogundade, A. I., E-mail: ajiunolorioba@gmail.com; Megat-Yusoff, P. S. M., E-mail: puteris@petronas.com.my; Faiz, A. [Department of Mechanical Engineering, Universiti Tecknologi Petronas (Malaysia); Bhat, A. H. [Department of Fundamental and Applied Science, Universiti Tecknologi Petronas (Malaysia)

    2015-07-22

    In this study, red mud (RM), an oxide waste was proposed as reinforcing, synergistic filler for the traditional epoxy intumescent coating (IC). 5.5 wt% of acid-modified and unmodified red mud were introduced into the basic intumescent formulation of ammonium polyphosphate (APP), pentaerythritol (PER) and melamine (MEL). In order to predict effect of modification on its suitability, Field emission electron scanning microscopy and Fourier transform infra red were used to obtain detailed characteristics such as the cell size, pore distribution, homogeneity and chemical composition of the red mud-epoxy carbonaceous char. Both acid-modified and unmodified RM-filled ICs produced chars with smaller and more closely packed cells compared to chars from the unfilled coating. Both coating types had hard carbonaceous metal phosphate coverings that could act as heat barriers. The unmodified red mud was found to be antagonistic to the intumescent action with an expansion of only 2 times the initial thickness. The leached, low iron-red mud produced an expansion of 15 times the initial thickness, but possessed a hollow interior. From these findings, it may be deduced that while acid leaching of red mud may improve intumescent expansion, it would be necessary to optimize the percent filler loading to improve residual mass.

  17. Characterization of red mud-epoxy intumescent char using surface imaging and micro analysis

    Science.gov (United States)

    Arogundade, A. I.; Megat-Yusoff, P. S. M.; Bhat, A. H.; Faiz, A.

    2015-07-01

    In this study, red mud (RM), an oxide waste was proposed as reinforcing, synergistic filler for the traditional epoxy intumescent coating (IC). 5.5 wt% of acid-modified and unmodified red mud were introduced into the basic intumescent formulation of ammonium polyphosphate (APP), pentaerythritol (PER) and melamine (MEL). In order to predict effect of modification on its suitability, Field emission electron scanning microscopy and Fourier transform infra red were used to obtain detailed characteristics such as the cell size, pore distribution, homogeneity and chemical composition of the red mud-epoxy carbonaceous char. Both acid-modified and unmodified RM-filled ICs produced chars with smaller and more closely packed cells compared to chars from the unfilled coating. Both coating types had hard carbonaceous metal phosphate coverings that could act as heat barriers. The unmodified red mud was found to be antagonistic to the intumescent action with an expansion of only 2 times the initial thickness. The leached, low iron-red mud produced an expansion of 15 times the initial thickness, but possessed a hollow interior. From these findings, it may be deduced that while acid leaching of red mud may improve intumescent expansion, it would be necessary to optimize the percent filler loading to improve residual mass.

  18. Characterization of red mud-epoxy intumescent char using surface imaging and micro analysis

    International Nuclear Information System (INIS)

    In this study, red mud (RM), an oxide waste was proposed as reinforcing, synergistic filler for the traditional epoxy intumescent coating (IC). 5.5 wt% of acid-modified and unmodified red mud were introduced into the basic intumescent formulation of ammonium polyphosphate (APP), pentaerythritol (PER) and melamine (MEL). In order to predict effect of modification on its suitability, Field emission electron scanning microscopy and Fourier transform infra red were used to obtain detailed characteristics such as the cell size, pore distribution, homogeneity and chemical composition of the red mud-epoxy carbonaceous char. Both acid-modified and unmodified RM-filled ICs produced chars with smaller and more closely packed cells compared to chars from the unfilled coating. Both coating types had hard carbonaceous metal phosphate coverings that could act as heat barriers. The unmodified red mud was found to be antagonistic to the intumescent action with an expansion of only 2 times the initial thickness. The leached, low iron-red mud produced an expansion of 15 times the initial thickness, but possessed a hollow interior. From these findings, it may be deduced that while acid leaching of red mud may improve intumescent expansion, it would be necessary to optimize the percent filler loading to improve residual mass

  19. Improvement in char formability of phenolic resin for development of Carbon/Carbon composites

    International Nuclear Information System (INIS)

    In the processing of carbon/carbon composites using polymer resin as the matrix precursor, it is inevitable that a porous structure was formed after carbonization. As a result, densification by liquid phase impregnation followed by recarbonization is required to obtain a densified composite. Consequently, the char formability of resin is an important factor in reducing the number of densification cycles and hence the processing cost. In this study, a novel approach is adopted to improve the densification of carbon/carbon composites by using a new phenolic resin modified by pitch. For this purpose, soluble part of pitch was extracted and dispersed in resol type phenolic resin. The polymerization reaction was performed in presence of para-formaldehyde and a resol-pitch compound was obtained. The second compound was prepared by mixing novolac-furfural in 55:45 weight ratio containing 9% by weight hexamethylene tetramine. This compound was added to resol-pitch compound in 10,20,50 and 80 w %. The microstructure of carbonized resin was investigated by X-ray diffraction and char yield, and the linear and volumetric shrinkage were obtained. Results show that in 80:20 ratio of resol-pitch to novolac-furfural , the char yield would be maximized by 71% and volumetric shrinkage would be minimized at 16.4%. At the same time, XRD results indicate that the resin has a strong ability to graphitize carbon/carbon composites matrix as a necessary step for its processing

  20. Preparation of Bamboo Chars and Bamboo Activated Carbons to Remove Color and COD from Ink Wastewater.

    Science.gov (United States)

    Hata, Motohide; Amano, Yoshimasa; Thiravetyan, Paitip; Machida, Motoi

    2016-01-01

    Bamboo chars and bamboo activated carbons prepared by steam activation were applied for ink wastewater treatment. Bamboo char at 800 °C was the best for the removal of color and chemical oxygen demand (COD) from ink wastewater compared to bamboo chars at 300 to 700 °C due to higher surface area and mesopore volume. Bamboo activated carbon at 600 °C (S600) was the best compared to bamboo activated carbon at 800 °C (S800), although S800 had larger surface area (1108 m(2)/g) than S600 (734 m(2)/g). S600 had higher mesopore volume (0.20 cm(3)/g) than S800 (0.16 cm(3)/g) and therefore achieved higher color and COD removal. All bamboo activated carbons showed higher color and COD removal efficiency than commercial activated carbon. In addition, S600 had the superior adsorption capacity for methylene blue (0.89 mmol/g). Therefore, bamboo is a suitable material to prepare adsorbents for removal of organic pollutants. PMID:26803031

  1. NO formation during oxy-fuel combustion of coal and biomass chars

    DEFF Research Database (Denmark)

    Zhao, Ke; Jensen, Anker Degn; Glarborg, Peter

    2014-01-01

    pronounced at 850 °C than at 1050-1150 °C. The present work indicates that the effect of CO2 on NO formation in oxy-fuel combustion in fluidized beds can partly be attributed to heterogeneous reactions, whereas for high-temperature pulverized fuel combustion, CO2 mainly affects the volatile chemistry. © 2014......The yields of NO from combustion of bituminous coal, lignite, and biomass chars were investigated in O2/N2 and O2/CO 2 atmospheres. The experiments were performed in a laboratory-scale fixed-bed reactor in the temperature range of 850-1150 °C. To minimize thermal deactivation during char...... preparation, the chars were generated by in situ pyrolysis at the reaction temperature. The NO yield clearly decreased and the CO yield increased when the atmosphere was altered from O2/N 2 to O2/CO2 at 850 °C, but only small differences in NO and CO yields were observed between the two atmospheres at 1050...

  2. CO{sub 2} and steam gasification of a grapefruit skin char

    Energy Technology Data Exchange (ETDEWEB)

    Marquez-Montesinos, F.; Cordero, T.; Rodriguez-Mirasol, J.; Rodriguez, J.J. [University of Pinar del Rio, Pinar del Rio (Cuba). Dept. of Chemistry

    2002-03-01

    A kinetic study on the gasification of carbonized grapefruit (Citrus Aurantium) skin with CO{sub 2} and with steam is presented. The chars from this agricultural waste show a comparatively high reactivity, which can be mostly attributed to the catalytic effect of the inorganic matter. The ash content of the carbonized substrate used in this work falls around 15% (db) potassium being the main metallic constituent. The reactivity for both, CO{sub 2} and steam gasification, increases at increasing conversion and also does the reactivity per unit surface area, consistently with the aforementioned catalytic effect. Lowering the ash content of the char by acid washing leads to a decrease of reactivity thus confirming the catalytic activity of the inorganic matter present in the starting material. Saturation of this catalytic effect was not detected within the conversion range investigated covering in most cases up to 0.85 - 0.9. Apparent activation energy values within the range of 200-250 kJ/mol have been obtained for CO{sub 2} gasification whereas the values obtained for steam gasification fall mostly between 130 and 170 kJ/mol. These values become comparable with the reported in the literature for other carbonaceous raw materials including chars from biomass residues and coals under chemical control conditions. 28 refs., 6 figs., 5 tabs.

  3. Bio-oil and bio-char production from corn cobs and stover by fast pyrolysis

    International Nuclear Information System (INIS)

    Bio-oil and bio-char were produced from corn cobs and corn stover (stalks, leaves and husks) by fast pyrolysis using a pilot scale fluidized bed reactor. Yields of 60% (mass/mass) bio-oil (high heating values are ∼20 MJ kg-1, and densities >1.0 Mg m-3) were realized from both corn cobs and from corn stover. The high energy density of bio-oil, ∼20-32 times on a per unit volume basis over the raw corn residues, offers potentially significant savings in transportation costs particularly for a distributed 'farm scale' bio-refinery system. Bio-char yield was 18.9% and 17.0% (mass/mass) from corn cobs and corn stover, respectively. Deploying the bio-char co-product, which contains most of the nutrient minerals from the corn residues, as well as a significant amount of carbon, to the land can enhance soil quality, sequester carbon, and alleviate environmental problems associated with removal of crop residues from fields.

  4. Suprasubduction volcanic rocks of the Char ophiolite belt, East Kazakhstan: new geochemical and first geochronological data

    Science.gov (United States)

    Safonova, Inna; Simonov, Vladimir; Seltmann, Reimar; Yamamoto, Shinji; Xiao, Wenjiao

    2016-04-01

    The Char ophiolite belt is located in the western Central Asian Orogenic Belt, a world largest accretionary orogen, which has evolved during more than 800 Ma. The Char belt formed during Kazakhstan - Siberia collision. It has been known for hosting fragments of Late Devonian-Early Carboniferous oceanic crust, MORB, OPB and OIB, of the Paleo-Asian Ocean (Safonova et al., 2012). The Char is surrounded by two Paleozoic island-arc terranes: Zharma-Saur in the west and Rudny Altai in the east, however, until recent times, no island-arc units have been found within it. We were the first to find island-arc units as tectonic sheets occurring adjacent to those consisting of oceanic rocks. In places, island-arc andesites cut oceanic basalts. The Char volcanic and subvolcanic rocks of a probable suprasubduction origin are basalt, microgabbro, dolerite, andesite, tonalite and dacite. The mafic to andesitic volcanics possessing low TiO2 (0.85 wt.%av.) and show MgO vs. major elements crystallization trends suggesting two magma series: tholeiitic and calc-alkaline. The tholeiitic varieties are less enriched in incompatible elements then the calc-alkaline ones. Two samples are high-Mg and low-Ti andesibasalts similar to boninites. The rocks possess moderately LREE enriched rare-earth element patterns and are characterized by negative Nb anomalies present on the multi-element spectra (Nb/Lapm = 0.14-0.47; Nb/Thpm = 0.7-1.6).The distribution of rare-earth elements (La/Smn = 0.8-2.3, Gd/Ybn = 0.7-1.9) and the results of geochemical modeling in the Nb-Yb system suggest high degrees of melting of a depleted harzburgite-bearing mantle source at spinel facies depths. Fractional crystallization of clinopyroxene, plagioclase and opaque minerals also affected the final composition of the volcanic rocks. Clinopyroxene monomineral thermometry indicates crystallization of melts at 1020-1180°C. Melt inclusion composition based numerical calculations show that primary melts were derived at 1350

  5. OPTIMIZATION OF SYNTHESIS AND CHARACTERIZATION OF PALM SHELL-BASED BIO-CHAR AS A BY-PRODUCT OF BIO-OIL PRODUCTION PROCESS

    OpenAIRE

    Arash Arami-Niya,; Mohammad Saleh Sahfeeyan,; Faisal Abnisa,; W. M. A. Wan Daud,; Jaya Narayan Sahu

    2011-01-01

    In this study the optimum preparation conditions of bio-char were achieved as a by-product of the bio-oil production process from oil palm shell as an agricultural waste material. To investigate the possibility of utilizing bio-char as an adsorbent for wastewater treatment and other applications, a central composite design was applied to investigate the influence of carbonization temperatures, nitrogen flow rates, particle sizes of precursor, and duration on the bio-char yield and methylene b...

  6. Role of char during reburning of nitrogen oxides. Tenth quarterly report, January 1, 1996--March 31, 1996

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Wei-Yin; Lu, Te-Chang; Tang, Lin [Mississippi Univ., University, MS (United States). Dept. of Chemical Engineering; Fan, L.T.; Meng, Fang [Kansas State Univ., Manhattan, KS (United States). Dept. of Chemical Engineering

    1996-03-31

    The four major tasks conducted during this quarter include: (1) extensive investigation in pore structures of chars before and after reactions with NO , CO,, and 02, (2) effects of pyrolysis time on char reactivities, (3) estimations of rates of NO reduction and mass transfer limitations, and, (4) char reactivities at low feed NO concentrations. Pore structure analyses include BET-N{sub 2}, BET-CO{sub 2}, and DR-CO{sub 2} surface areas, pore size distribution, micropore volume, total pore volume, and average pore radius. These studies suggest that neither BET-N{sub 2} nor DR-CO{sub 2} surface area is a normalization factor of chars of different origin. Parameter study reveals that the effectiveness of heterogeneous reburning strongly depends on variables in three areas: (1) the origin of char, (2) char devolatilization temperature and time, and, (3) the competitions of NO with C0{sub 2} and 02 for the active sites on the char surface. The studies on pore structure and on parameter screening signify the importance of transient kinetics (TK) and temperature programmed desorption (TPD) in the future research. These two techniques all lead to the direct measurements of both stable and reactive surface oxygen complexes, reactive surface area, and the Langmuir-Hinshelwood model which has both importance to both fundamental understanding of reaction mechanisms and to industrial practice. Estimation of rate of NO reduction has been established to include the conversions in the nonisothermal and isothermal regions of the flow reactor, and internal mass transfer limitations. Solving a set of equations simultaneously with MathCad gives frequency factor, activation energy, Thiele modulus, and effectiveness factor.

  7. Near infrared spectroscopic examination of charred pine wood, bark, cellulose and lignin: Implications for the quantitative determination of charcoal in soils

    Science.gov (United States)

    Reeves, J. B., III; McCarty, G.W.; Rutherford, D.W.; Wershaw, R. L.

    2007-01-01

    The objective of this research was to investigate the effect of charring on near infrared spectra of materials likely to be present in forest fires in order to determine the feasibility of determining charred carbon in soils. Four materials (cellulose, lignin, pine bark and pine wood) and char from these materials created by charring for various durations (1 to 168 h) and at various temperatures (200 to 450??C) were studied. Near infrared spectra and measures of acidity (total acids, carboxylic acids, lactones and phenols as determined by titration) were available for 56 different samples (Not all samples charred at all temperatures/durations). Results showed spectral changes that varied with the material, temperature and duration of charring. Examination of spectra and correlation plots indicated that changes in the constituents of the materials in question, such as loss of OH groups in carbohydrates, rather than direct determination of typical products produced by charring, such as carboxylic acids, lactones and phenols, were the basis for the spectral changes. Finally, while the spectral changes resulting from charring appeared to be relatively unique to each material, PLS calibrations for total acids, carboxylic acids, lactones and phenols were successfully created (with R2 of 0.991, 0.943, 0.931 and 0.944, respectively) indicating that there is a sufficient commonality in the changes to develop calibrations without the need for unique calibrations for each specific set of charring conditions (i.e. material, temperature and time of heating). ?? IM Publications 2007.

  8. Kinetic models for the oxy-fuel combustion of coal and coal/biomass blend chars obtained in N2 and CO2 atmospheres

    OpenAIRE

    Gil Matellanes, María Victoria; Riaza Benito, Juan; Álvarez González, Lucía; Pevida García, Covadonga; Pis Martínez, José Juan; Rubiera González, Fernando

    2012-01-01

    The thermal reactivity and kinetics of five coal chars, a biomass char, and two coal/biomass char blends in an oxy-fuel combustion atmosphere (30%O2–70%CO2) were studied using the non-isothermal thermogravimetric method at three heating rates. Fuel chars were obtained by devolatilization in an entrained flow reactor at 1273 K under N2 and CO2 atmospheres. Three nth-order representative gas–solid models – the volumetric model (VM), the grain model (GM) and the random pore model (RPM) – were em...

  9. A Study on the Applicability of Kinetic Models for Shenfu Coal Char Gasification with CO2 at Elevated Temperatures

    Directory of Open Access Journals (Sweden)

    Jinsheng Gao

    2009-07-01

    Full Text Available In this paper, measurements of the CO2 gasification kinetics for two types of Shenfu coal chars, which were respectively prepared by slow and rapid pyrolysis at temperatures of 950 °C and 1,400 °C, were performed by an isothermal thermo-gravimetric analysis under ambient pressure and elevated temperature conditions. Simultaneously, the applicability of the kinetic model for the CO2 gasification reaction of Shenfu coal chars was discussed. The results showed: (i the shrinking un-reacted core model was not appropriate to describe the gasification reaction process of Shenfu coal chars with CO2 in the whole experimental temperature range; (ii at the relatively low temperatures, the modified volumetric model was as good as the random pore model to simulate the CO2 gasification reaction of Shenfu coal chars, while at the elevated temperatures, the modified volumetric model was superior to the random pore model for this process; (iii the integral expression of the modified volumetric model was more favorable than the differential expression of that for fitting the experimental data. Moreover, by simply introducing a function: A = A★exp(ft, it was found that the extensive model of the modified volumetric model could make much better predictions than the modified volumetric model. It was recommended as a convenient empirical model for comprehensive simulation of Shenfu coal char gasification with under conditions close to those of entrained flow gasification.

  10. Effect of Kaolin Clay and Alumina on Thermal Performance and Char Morphology of Intumescent fire retardant coating

    Directory of Open Access Journals (Sweden)

    aziz Hammad

    2014-07-01

    Full Text Available Intumescent fire retardant coating (IFRC have been developed by using ammonium polyphosphate, expandable graphite, melamine, boric acid, kaolin clay and alumina as fillers bound together with epoxy resin and cured with the help of curing agent. Five different formulations were developed with and without using fillers. Cured samples were burned in furnace at 500°C for 2h for char expansion. Bunsen burner test was performed for 1h using UL-94 vertical burning test to investigate the thermal performance of IFRC. The resultant char obtained after burning of coated samples were characterized by using field emission scanning electron microscopy for char morphology. Char composition was analyzed by using fourier transform infrared spectroscopy. Thermogravimetric analysis was carried out to investigate the residual weight of coating. Results showed that formulation with 0.5 weight % of kaolin clay and 0.5 weight % of alumina provide best thermal performance, uniform and multi-porous char structure with high anti-oxidation property.

  11. Determination of the intrinsic reactivities for carbon dioxide gasification of rice husk chars through using random pore model.

    Science.gov (United States)

    Gao, Xiaoyan; Zhang, Yaning; Li, Bingxi; Zhao, Yijun; Jiang, Baocheng

    2016-10-01

    Rice husk is abundantly available and environmentally friendly, and char-CO2 gasification is of great importance for the biomass gasification process. The intrinsic reaction rates of carbon dioxide gasification with rice husk chars derived from different pyrolysis temperatures were investigated in this study by conducting thermogravimetric analysis (TGA) measurements. The effects of gasification temperature and reactant partial pressure on the char-CO2 gasification were investigated and the random pore model (RPM) was used to determine the intrinsic kinetic parameters based on the experimental data. The results obtained from this study show that the activation energy, reaction order and pre-exponential factor varied in the ranges of 226.65-232.28kJ/mol, 0.288-0.346 and 2.38×10(5)-2.82×10(5)1/sPa(n) for the rice husk chars pyrolyzed at 700-900°C, respectively. All the determination coefficients between the RPM predictions and experimental results were higher than 0.906, indicating the RPM is reliable for determining and evaluating the intrinsic reactivities of rice husk chars. PMID:27459684

  12. Physico-chemical characterization of metal-doped bone chars and their adsorption behavior for water defluoridation

    Science.gov (United States)

    Rojas-Mayorga, C. K.; Bonilla-Petriciolet, A.; Silvestre-Albero, J.; Aguayo-Villarreal, I. A.; Mendoza-Castillo, D. I.

    2015-11-01

    New bone chars for fluoride adsorption from drinking water have been synthetized via metallic doping using aluminum and iron salts. A detailed statistical analysis of the metal doping process using the signal-to-noise ratios from Taguchi's experimental designs and its impact on the fluoride adsorption properties of modified bone chars have been performed. The best conditions, including the proper metallic salt, for metal doping were identified to improve the fluoride uptakes of modified bone chars. Results showed that the fluoride adsorption properties of bone chars can be enhanced up to 600% using aluminum sulfate for the surface modification. This aluminum-based adsorbent showed an adsorption capacity of 31 mg/g, which outperformed the fluoride uptakes reported for several adsorbents. Surface interactions involved in the defluoridation process were established using FTIR, DRX and XPS analysis. Defluoridation using the metal-doped bone chars occurred via an ion exchange process between fluoride ions and the hydroxyl groups on the adsorbent surface, whereas the Al(OH)xFy, FexFy, and CaF2 interactions could play also an important role in the removal process. These metal-doped adsorbents anticipate a promising behavior in water treatment, especially in developing countries where the efficiency - cost tradeoff is crucial for implementing new defluoridation technologies.

  13. Char-recirculation biomass gasification system--a site-specific feasibility study

    International Nuclear Information System (INIS)

    A site-specific feasibility study was conducted for a char-recirculation biomass gasification plant which would dispose of the chippable solid residues of the area sawmills. The plant would receive green hardwood chips and convert them into active charcoal while producing process steam and electrical power. An economic analysis was performed on the basis of not-for-profit operation, marketing crushed active charcoal to a broker at a discounted price, and displacing purchased electric power. Given a market for the active charcoal, the plant was judged to be economically viable

  14. Importance of fragmentation on the steady state combustion of wood char in a bubbling fluidized bed

    Energy Technology Data Exchange (ETDEWEB)

    Pinho, Carlos [Universidade do Porto (CEFT/FEUP), Porto (Portugal). Faculdade de Engenharia. Centro de Estudos de Fenomenos de Transporte], E-mail: ctp@fe.up.pt

    2010-07-01

    A simple mathematical model for the analysis of the steady state behavior of a bubbling fluidized bed burner is presented, with the main intention of evaluating the importance of the primary fragmentation of fuel particles on the performance of this type of burners. This model has pedagogical advantages because of its simplicity and easiness of application to the analysis of realistic situations. The model is based upon the classical models used for the study of batch combustion processes in fluidized bed reactors. Experimental data from studies of fluidized bed combustion of portuguese vegetable chars are used to support the analysis of the performance of a 1 m diameter fluidized bed combustor. (author)

  15. Inverse Heat Conduction Methods in the CHAR Code for Aerothermal Flight Data Reconstruction

    Science.gov (United States)

    Oliver, A. Brandon; Amar, Adam J.

    2016-01-01

    Reconstruction of flight aerothermal environments often requires the solution of an inverse heat transfer problem, which is an ill-posed problem of determining boundary conditions from discrete measurements in the interior of the domain. This paper will present the algorithms implemented in the CHAR code for use in reconstruction of EFT-1 flight data and future testing activities. Implementation details will be discussed, and alternative hybrid-methods that are permitted by the implementation will be described. Results will be presented for a number of problems.

  16. Removal of Methylene Blue Dye from Synthetic Wastewater with Bone Char

    OpenAIRE

    Gh Ghanizadeh; G Asgari

    2009-01-01

    "n "n "nBackgrounds and Objectives: Dyes  are  organic  materials  with  complex structures, toxic,  carcinogenic, teratogenic,nonbiodegredable properties and!the most!important pollutants of textile industrial wastewaters. The goal of this study was to survey the feasibility application of bone char (BC) as a sorbent for the  of methylene blue (MB) from synthetic wastewater.The sub goals of the research!were to determine!the adsorption isotherm, !effects of...

  17. EFFECT OF CALCIUM ADDITION ON THE DEFLUORIDATION CAPACITY OF BONE CHAR

    DEFF Research Database (Denmark)

    Jacobsen, P.; Dahi, Elian

    1997-01-01

    Dosage of small amounts of calcium chloride to fluoride water prior to contact with bone char which has already been saturated with fluoride is shown to provide an additional fluoride removal capacity. The additionally obtained removal capacity increases with slower filtration velocities and...... capable of reducing the fluoride concentration form 10 to about 0.5 mgF/L. The additionally saturated column is shown to be regenerated by simple adjustment of the pH of the water to 11 and allowing to flow for a few bed volumes. The useful regeneration capacity, where the fluoride concentration is...

  18. Prediction and validation of burnout curves for Goettelborn char using reaction kinetics determined in shock tube experiments

    Energy Technology Data Exchange (ETDEWEB)

    Moors, J.H.J.; Banin, V.E.; Haas, J.H.P.; Weber, R.; Veefkind, A. [Eindhoven University of Technology, Eindhoven (Netherlands). Dept. of Applied Physics

    1999-01-01

    Using a shock tube facility the combustion characteristics of pulverised char ({lt} 10 {mu}m) were measured. A prediction was made for the burnout behaviour of a commercial sized char particle (75-90 {mu}m) in different ambient conditions using a `pseudo kinetic` approach. In this approach the kinetic rate of a surface containing micro pores is determined and these `pseudo kinetics` are then applied to the larger particle not taking into account the micro pores. Comparison of the predictions with measurements done with an isothermal plug flow reactor showed this approach to be valid within experimental error for low burnout. A linear decrease of the kinetic reaction rate with burnout is shown to predict the burnout behaviour in the complete range of burnout. A possible explanation for this linear decrease could be a growing fraction of non-combustible material in the char particles during burnout. 11 refs., 6 figs., 2 tabs.

  19. Kinetics of coal char gasification with CO2: Impact of internal/external diffusion at high temperature and elevated pressure

    International Nuclear Information System (INIS)

    Highlights: • Pressurized wire-heating reactor (PWHR) was designed for CO2 gasification kinetics coal char. • PWHR can provide experimental conditions up to 50 atm and 1750 K. • The intrinsic activation energies based on nth order reaction rate equation were determined. • The effectiveness factor was analyzed to determine the effects of pressure and temperature. - Abstract: A pressurized wire-heating reactor (PWHR) that can provide experimental conditions up to pressures and temperatures of 50 atm and 1750 K, respectively, was developed to evaluate the intrinsic reaction kinetics of CO2 gasification for Berau sub-bituminous coal char (Indonesian coal) at elevated pressure using a synchronized experimental method. This synchronization system consists of a thermocouple wire for both heating and direct measurement of the particle temperature and a photodetector sensor for measuring the intensity of the luminous emission from the reaction particle to determine the ignition/burnout points. The intrinsic reaction kinetics obtained from PWHR, which was analyzed from nth order reaction rate equations, was verified by comparison with TGA results. The internal/external effectiveness factor was analyzed to determine the effects of high pressure (up to 30 atm) and temperature (up to 1723 K) on char-CO2 gasification. Accordingly, the intrinsic activation energies based on nth order reaction rate equation were determined to be 152 kJ/mol (via TGA, 75 μm char particle), 150 kJ/mol (via TGA, 800 μm char particle), and 149.2 kJ/mol (via PWHR, 800 μm char particle)

  20. ADSORPTION OF MANGANESE FROM ACID MINE DRAINAGE EFFLUENTS USING BONE CHAR: CONTINUOUS FIXED BED COLUMN AND BATCH DESORPTION STUDIES

    Directory of Open Access Journals (Sweden)

    D. C. Sicupira

    2015-06-01

    Full Text Available AbstractIn the present study, continuous fixed bed column runs were carried out in an attempt to evaluate the feasibility of using bone char for the removal of manganese from acid mine drainage (AMD. Tests using a laboratory solution of pure manganese at typical concentration levels were also performed for comparison purposes. The following operating variables were evaluated: column height, flow rate, and initial pH. Significant variations in resistance to the mass transfer of manganese into the bone char were identified using the Thomas model. A significant effect of the bed height could only be observed in tests using the laboratory solution. No significant change in the breakthrough volume could be observed with different flow rates. By increasing the initial pH from 2.96 to 5.50, the breakthrough volume was also increased. The maximum manganese loading capacity in continuous tests using bone char for AMD effluents was 6.03 mg g-1, as compared to 26.74 mg g-1 when using the laboratory solution. The present study also performed desorption tests, using solutions of HCl, H2SO4, and water, aimed at the reuse of the adsorbent; however, no promising results were obtained due to low desorption levels associated with a relatively high mass loss. Despite the desorption results, the removal of manganese from AMD effluents using bone char as an adsorbent is technically feasible and attends to environmental legislation. It is interesting to note that the use of bone char for manganese removal may avoid the need for pH corrections of effluents after treatment. Moreover, bone char can also serve to remove fluoride ions and other metals, thus representing an interesting alternative material for the treatment of AMD effluents.

  1. Carbon Sequestration and Nitrogen Mineralization in Soil Cooperated with Organic Composts and Bio-char During Corn (Zea mays) Cultivation

    Science.gov (United States)

    Shin, Joung-Du; Lee, Sun-Ill; Park, Wu-Gyun; Choi, Yong-Su; Hong, Seong-Gil; Park, Sang-Won

    2014-05-01

    Objectives of this study were to estimate the carbon sequestration and to evaluate nitrogen mineralization and nitrification in soils cooperated with organic composts and bio-char during corn cultivation. For the experiment, the soil used in this study was clay loam types, and application rates of chemical fertilizer and bio-char were recommended amount after soil test and 2 % to soil weight, respectively. The soil samples were periodically taken at every 15 day intervals during the experimental periods. The treatments were consisted of non-application, cow manure compost, pig manure compost, swine digestate from aerobic digestion system, their bio-char cooperation. For the experimental results, residual amount of inorganic carbon was ranged from 51 to 208kg 10a-1 in soil only cooperated with different organic composts. However it was estimated to be highest at 208kg 10a-1 in the application plot of pig manure compost. In addition to bio-char application, it was ranged from 187.8 to 286kg 10a-1, but was greatest accumulated at 160.3kg 10a-1 in the application plot of cow manure compost. For nitrogen mineralization and nitrification rates, it was shown that there were generally low in the soil cooperated with bio-char compared to the only application plots of different organic composts except for 71 days after sowing. Also, they were observed to be highest in the application plot of swine digestate from aerobic digestion system. For the loss of total inorganic carbon (TIC) by run-off water, it was ranged from 0.18 to 0.36 kg 10a-1 in the different treatment plots. Also, with application of bio-char, total nitrogen was estimated to be reduced at 0.42(15.1%) and 0.38(11.8%) kg 10a-1 in application plots of the pig manure compost and aerobic digestate, respectively.

  2. Measurement and modeling the coefficient of restitution of char particles under simulated entrained flow gasifier conditions

    Science.gov (United States)

    Gibson, LaTosha M.

    Inefficiencies in plant operations due to carbon loss in flyash, necessitate control of ash deposition and the handling of the slag disposal. Excessive char/ash deposition in convective coolers causes reduction in the heat transfer, both in the radiative (slagging) section and in the low-temperature convective (fouling) heating section. This can lead to unplanned shutdowns and result in an increased cost of electricity generation. CFD models for entrained flow gasification have used the average bulk coal composition to simulate slagging and ash deposition with a narrow particle size distribution (PSD). However, the variations in mineral (inorganic) and macerals (organic) components in coal have led to particles with a variation in their inorganic and organic composition after grinding as governed by their Particle Size Distribution (PSD) and mineral liberation kinetics. As a result, each particle in a PSD of coal exhibits differences in its conversion, particle trajectory within the gasifier, fragmentation, swelling, and slagging probability depending on the gasifier conditions (such as the temperature, coal to oxygen ratio, and swirling capacity of the coal injector). Given the heterogeneous behavior of char particles within a gasifier, the main objective of this work was to determine boundary conditions of char particle adhering and/or rebounding from the refractory wall or a layer of previously adhered particles. In the past, viscosity models based on the influence of ash composition have been used as the method to characterize sticking. It is well documented that carbon contributes to the non-wettability of particles. Therefore, it has been hypothesized that viscosity models would not be adequate to accurately predict the adhesion behavior of char. Certain particle wall impact models have incorporated surface tension which can account the contributions of the carbon content to the adhesive properties of a char particle. These particle wall impact models also

  3. Characterization and biodegradation of water-soluble biomarkers and organic carbon extracted from low temperature chars

    Energy Technology Data Exchange (ETDEWEB)

    Norwood, Matt J.; Louchouarn, Patrick; Kuo, Li-Jung; Harvey, Omar

    2013-03-16

    This study demonstrates that wildfires/biomass combustion may be an important source of labile pyrogenic water-soluble organic matter (Py-WSOM) to aquatic systems. Spectroscopic analysis (of the solid char and Py-WSOM) with Fourier transform infrared spectroscopy (FTIR) indicated that the Py-WSOM extracted from two low temperature chars (one wood, one grass) was dominated by polar moieties (-OH and C-O) derived from depolymerization and fragmentation of lignocellulose. Incubation experiments under aerobic conditions with unsterilized river water suggested that Py-WSOM and associated biomarkers may have turnover rates on the order of weeks to months, consistent with mixing and transport conditions of riverine systems. For example, pyrogenic dissolved organic carbon (Py-DOC) had a half-life of 30-40 days. Turnover rate for the combustion biomarkers was shorter, with levoglucosan and free lignin phenols having a half-life around 3-4 days and polymeric lignin components 13-14 days. The latter observations contradict earlier studies on the biodegradation of dissolved lignin and point to the need for re-assessment of lignin degradation kinetics in well-mixed riverine systems, particularly when such lignin components are derived from thermally altered plant material that may exist in a form more labile than that in highly processed riverine DOM.

  4. The use of activated char for flue gas polishing in municipal and hazardous waste combustors

    Energy Technology Data Exchange (ETDEWEB)

    Hartenstein, H.U.; Steinmueller, L.C.

    1996-10-01

    In the year of 1989/1990 stringent new emission requirements were introduced for municipal (MWC`s) and hazardous waste combustors (HWC`s) in Central Europe. These laws reducing not only the former emission values of most pollutants by a factor of 20 or more, also introduced new pollutants to be regulated such as dioxins (PCDD`s) and furans (PCDF`s). In order to meet these new laws a new generation of air pollution control (APC) equipment had to developed. Most of the new techniques are based on the use of some kind of activated carbon which allows for the low emission values required. This paper describes the ACR (activated char reactor) technology developed by the L. & C. Steinmutler GmbH, Gummersbach through its 100% subsidiary Hugo Petersen GmbH & Co. KG, Wiesbaden Germany. The ACR technology utilizes the excellent adsorption capabilities of activated char for a wide variety of air pollutants at the tail end and of the APC-train for flue gas polishing. The paper details the design as well as the removal capabilities of the technique. It outlines several full scale applications in Europe an provides data from various installations.

  5. A downdraft high temperature steam-only solar gasifier of biomass char: A modelling study

    International Nuclear Information System (INIS)

    A numerical model of a solar downdraft gasifier of biomass char (biochar) with steam based on the systems kinetics is developed. The model calculates the dynamic and steady state profiles, predicting the temperature and concentration profiles of gas and solid phases, based on the mass and heat balances. The Rosseland equation is used to calculate the radiative transfer within the bed. The char reactivity factor (CFR) is taken into account with an exponential variation. The bed heating dynamics as well as the steam velocity effects are tested. The model results are compared with different experimental results from a solar packed bed gasifier, and the temperature profile is compared to an experimental downdraft gasifier. Hydrogen is the principal product followed by carbon monoxide, the carbon dioxide production is small and the methane production is negligible, indicating a high quality syngas production. By applying the temperature gradient theory in the steam-only gasification process for a solar gasifier design, a solar downdraft gasifier improves the energy conversion efficiency by over 20% when compared to a solar packed bed gasifier. The model predictions are in good agreement with the experimental results found in the literature. -- Highlights: → The solar downdraft gasifier set-up improve the solar updraft gasifier performance. → The temperature gradient theory is introduced. → A high quality syngas produced, the hydrogen is the principal component. → An exponential CFR variation is adjusted to the heat transfer in the bed.

  6. Specific heat and thermal conductivity of softwood bark and softwood char particles

    Energy Technology Data Exchange (ETDEWEB)

    Murlidhar Gupta; Jin Yang; Christian Roy [Universite Laval, Sainte-Foy, PQ (Canada). Department of Chemical Engineering

    2003-05-01

    Very few data exist regarding the thermal properties of softwood bark and therein derived softwood chars. This work describes the measurement of specific heat and particle thermal conductivity of softwood (SW), softwood bark (SB) and therein derived softwood char (SC). Differential scanning calorimetery (DSC) was used to measure the specific heat. At 313 K, the measured specific heat was found to be 1172, 1364 and 768 J kg{sup -1} K{sup -1} for SW, SB and SC, respectively. The specific heat of SW and SB increased linearly from 1172 to 1726 and 1364 to 1777 J kg{sup -1} K{sup -1}, respectively, with an increase in temperature from 313 to 413 K. With an increase in temperature from 313 to 713 K, the specific heat of SC doubled from 768 to 1506 J kg{sup -1} K{sup -1} and followed a polynomial relationship with temperature. A modified Fitch apparatus was constructed, calibrated and used for measurement of particle conductivity of SW, SB and SC. The particle thermal conductivity of SB was found to be twice that of SC, i.e. 0.2050 and 0.0946 W m{sup -1} K{sup -1}, respectively, at 310 K. The particle thermal conductivity of SW, SB and SC followed a linear increase with temperature. 32 refs., 6 figs., 4 tabs.

  7. Advanced char burnout models for the simulation of pulverized coal fired boilers

    Energy Technology Data Exchange (ETDEWEB)

    T. Severin; S. Wirtz; V. Scherer [Ruhr-University, Bochum (Germany). Institute of Energy Plant Technology (LEAT)

    2005-07-01

    The numerical simulation of coal combustion processes is widely used as an efficient means to predict burner or system behaviour. In this paper an approach to improve CFD simulations of pulverized coal fired boilers with advanced coal combustion models is presented. In simple coal combustion models, first order Arrhenius rate equations are used for devolatilization and char burnout. The accuracy of such simple models is sufficient for the basic aspects of heat release. The prediction of carbon-in-ash is one aspect of special interest in the simulation of pulverized coal fired boilers. To determine the carbon-in-ash levels in the fly ash of coal fired furnaces, the char burnout model has to be more detailed. It was tested, in how far changing operating conditions affect the carbon-in-ash prediction of the simulation. To run several test cases in a short time, a simplified cellnet model was applied. To use a cellnet model for simulations of pulverized coal fired boilers, it was coupled with a Lagrangian particle model, used in CFD simulations, too. 18 refs., 5 figs., 5 tabs.

  8. Bone char surface modification by nano-gold coating for elemental mercury vapor removal

    Science.gov (United States)

    Assari, Mohamad javad; Rezaee, Abbas; Rangkooy, Hossinali

    2015-07-01

    The present work was done to develop a novel nanocomposite using bone char coated with nano-gold for capture of elemental mercury (Hg0) from air. The morphologies, structures, and chemical constitute of the prepared nanocomposite were evaluated by UV-VIS-NIR, dynamic light-scattering (DLS), X-ray diffraction (XRD), transmission electron microscopy (TEM), Fourier transform infra-red (FTIR) spectroscopy, and energy dispersive X-ray spectroscopy (EDS). The capture performance of nanocomposite was evaluated in a needle trap for mercury vapor. An on-line setup based on cold vapor atomic absorption spectrometry (CVAAS) was designed for Hg0 determination. Dynamic capacity of nanocomposite for Hg0 was shown high efficient operating capacity of 586.7 μg/g. As temperature increases, the dynamic adsorption capacity of the nanocomposite was decreased, which are characteristics of physicosorption processes. It was found that the surface modification of bone char with nano-gold has various advantages such as high operating dynamic adsorption capacity and low cost preparation. It was also demonstrated that the developed nanocomposite is suitable for on-line monitoring of Hg0. It could be applied for the laboratory and field studies.

  9. Inverse estimation of properties for charring material using a hybrid genetic algorithm

    International Nuclear Information System (INIS)

    Fire characteristics can be analyzed more realistically by using more accurate material properties related to the fire dynamics and one way to acquire these fire properties is to use one of the inverse property estimation techniques. In this study an optimization algorithm which is frequently applied for the inverse heat transfer problems is selected to demonstrate the procedure of obtaining fire properties of a solid charring material with relatively simple chemical structure. Thermal decomposition is occurred at the surface of the test plate by receiving the radiative energy from external heat sources and in this process the heat transfer through the test plate can be simplified by an unsteady one dimensional problem. The input parameters for the analyses are the surface temperature and mass loss rate of the char plate which are determined from the actual experiment of from the unsteady one-dimensional analysis with a given set of eight properties. The performance of hybrid genetic algorithm (HGA) is compare with a basic genetic algorithm (GA) in order to examine its performance. This comparison is carried out for the inverse property problem of estimating the fire properties related to the reaction pyrolysis of some relatively simple materials; redwood and red oak. Results show that the hybrid genetic algorithm has better performance in estimating the eight pyrolysis properties than the genetic algorithm

  10. Application of Wood Char in Processing Oolitic High-phosphorus Hematite for Phosphorus Removal

    Institute of Scientific and Technical Information of China (English)

    Hui-qing TANG; Yan-qi QIN; Teng-fei QI; Zhi-lei DONG; Qing-guo XUE

    2016-01-01

    Phosphorus removal from oolitic high-phosphorus hematite using direct reduction followed by melting sep-aration was investigated.At the direct reduction stage,highly volatile wood char was prepared by carbonizing j uj ube wood at 673 K for 2 h and was used as reducing agent.The results of the direct reduction tests show that at a tem-perature of 1 373 K,a char mixing ratio of 0�8,and a reduction time of 10-25 min,the briquettes reached a metal-lization degree of 80%-84% and a residual carbon content of 0�13-1�98 mass%.Phosphorus remained in the gangue as calcium phosphate after reduction.The results of the melting separation tests show that residual carbon in reduced briquette negatively affects the phosphorus content (w[P])in hot metal.When the reduced briquettes ob-tained under the aforementioned conditions were used for melting separation,hot metal suitable for basic oxygen steelmaking (w[P]<0�4 mass%)could not be obtained from metallic briquettes with a residual carbon content more than 1�0 mass%.In contrast,it could be obtained from metallic briquettes with residual carbon content less than 0�35 mass% by mixing with 2%-4% Na2 CO3 .

  11. Char crystalline transformations during coal combustion and their implications for carbon burnout

    Energy Technology Data Exchange (ETDEWEB)

    Hurt, R.H.

    1999-03-11

    Residual, or unburned carbon in fly ash affects many aspects of power plant performance and economy including boiler efficiency, electrostatic precipitator operation, and ash as a salable byproduct. There is a large concern in industry on the unburned carbon problem due to a variety of factors, including low-NOx combustion system and internationalization of the coal market. In recent work, it has been found that residual carbon extracted from fly ash is much less reactive than the laboratory chars on which the current kinetics are based. It has been suggested that thermal deactivation at the peak temperature in combustion is a likely phenomenon and that the structural ordering is one key mechanism. The general phenomenon of carbon thermal annealing is well known, but there is a critical need for more data on the temperature and time scale of interest to combustion. In addition, high resolution transmission electron microscopy (HRTEM) fringe imaging, which provides a wealth of information on the nature and degree of crystallinity in carbon materials such as coal chars, has become available. Motivated by these new developments, this University Coal Research project has been initiated with the following goals: to determine transient, high-temperature, thermal deactivation kinetics as a function of parent coal and temperature history; and to characterize the effect of this thermal treatment on carbon crystalline structure through high-resolution transmission electron microscopy and specialized, quantitative image analysis.

  12. Char crystalline transformations during coal combustion and their implications for carbon burnout

    Energy Technology Data Exchange (ETDEWEB)

    Hurt, R.H.

    1999-07-07

    Residual, or unburned carbon in fly ash affects many aspects of power plant performance and economy including boiler efficiency, electrostatic precipitator operation, and ash as a salable byproduct. There is a large concern in industry on the unburned carbon problem due to a variety of factors, including low-NOx combustion system and internationalization of the coal market. In recent work, it has been found that residual carbon extracted from fly ash is much less reactive than the laboratory chars on which the current kinetics are based. It has been suggested that thermal deactivation at the peak temperature in combustion is a likely phenomenon and that the structural ordering is one key mechanism. The general phenomenon of carbon thermal annealing is well known, but there is a critical need for more data on the temperature and time scale of interest to combustion. In addition, high resolution transmission electron microscopy (HRTEM) fringe imaging, which provides a wealth of information on the nature and degree of crystallinity in carbon materials such as coal chars, has become available. Motivated by these new developments, this University Coal Research project has been initiated with the following goals: (1) To determine transient, high-temperature, thermal deactivation kinetics as a function of parent coal and temperature history. (2) To characterize the effect of the thermal treatment on carbon crystalline structure through high-resolution transmission electron microscopy and specialized, quantitative image analysis.

  13. Biochemical stability of sewage sludge chars and their impact on soil organic matter of a Mediterranean Cambisol

    Science.gov (United States)

    Paneque, Marina; María De la Rosa, José; Aragón, Carlos; Kern, Jürgen; Knicker, Heike

    2016-04-01

    Transformation of sewage sludge (SS) into char achieves sludge hygienisation, which is necessary prior its application into agricultural soils. The pyrolysis of SS increases its stability in a degree which depends on the thermal treatment used. Thus, chars produced by using hydrothermal carbonization are typically more stable than normal soil organic matter (SOM), but less stable than chars from dry pyrolysis (Libra et al., 2011). Addition of highly-recalcitrant SS-chars to soil will likely increase its carbon sequestration potential; however the fertilizing properties of SS may be compromised due to its alteration during the pyrolysis. The main goal of this work was to investigate the biochemical recalcitrance of two 13C-enriched SS-chars once applied in a Mediterranean Cambisol as well as to evaluate their impact on the SOM quality and carbon stability. Thus, we studied the distribution of 13C between plants and soil after the addition of the 13C-enriched chars (2 atm%) to the soil. Therefore, we performed a greenhouse incubation experiment, using a Mediterranean Cambisol as matrix and tested the following treatments: control (soil alone), raw SS, SS-hydrochar, SS-pyrochar. The SS was produced in a pilot-scale waste-water plant and enriched with 13C by the addition of 13C-glucose during the treatment. The amendment was only applied to the upper 2 cm of the soil matrix where it accounted for 5% of its dry weight. Per pot, 25 seeds of Lolium perenne were sowed and incubated under controlled conditions. The biomass production as well as the concentration of 13C in leaves and roots was determined after 1, 2 and 5 months. The partitioning of the 13C between soil and plant and its transformation into bioavailable forms were monitored by stable isotopic mass spectrometry. The 13C-enrichment of the chars allowed the use of solid-state 13C NMR spectroscopy as a means for the detection of chemical alterations of the chars during their aging. Libra J., Ro K., Kammann C

  14. The different effects of applying fresh, composted or charred manure on soil N2O emissions

    DEFF Research Database (Denmark)

    Zhu, Kun; Christel, Wibke; Bruun, Sander;

    2014-01-01

    after soil application. A laboratory study was conducted over a period of 100 days to investigate the N2O emissions from arable soil amended with different manure-derived fertilisers: fresh, composted and charred solid fraction of pig manure. The importance of several factors (fertiliser type, soil...... water potential, homogeneous or heterogeneous distribution of amendments in soil) was evaluated in this study. The mitigation potential of the combined application of charred manure with other amendments was also investigated. The application of fresh or composted manure solids was observed to have much...

  15. Mid-infrared diffuse reflectance spectroscopic examination of charred pine wood, bark, cellulose, and lignin: Implications for the quantitative determination of charcoal in soils

    Science.gov (United States)

    Reeves, J. B., III; McCarty, G.W.; Rutherford, D.W.; Wershaw, R. L.

    2008-01-01

    Fires in terrestrial ecosystems produce large amounts of charcoal that persist in the environment and represent a substantial pool of sequestered carbon in soil. The objective of this research was to investigate the effect of charring on mid-infrared spectra of materials likely to be present in forest fires in order to determine the feasibility of determining charred organic matter in soils. Four materials (cellulose, lignin, pine bark, and pine wood) and char from these materials, created by charring for various durations (1 to 168 h) and at various temperatures (200 to 450 ??C), were studied. Mid-infrared spectra and measures of acidity (total acids, carboxylic acids, lactones, and phenols as determined by titration) were determined for 56 different samples (not all samples were charred at all temperatures/durations). Results showed spectral changes that varied with the material, temperature, and duration of charring. Despite the wide range of spectral changes seen with the differing materials and length/temperature of charring, partial least squares calibrations for total acids, carboxylic acids, lactones, and phenols were successfully created (coefficient of determination and root mean squared deviation of 0.970 and 0.380; 0.933 and 0.227; 0.976 and 0.120; and 0.982 and 0.101 meq/g, respectively), indicating that there is a sufficient commonality in the changes to develop calibrations without the need for unique calibrations for each specific material or condition of char formation. ?? 2008 Society for Applied Spectroscopy.

  16. Combustion of char-coal waste pellets for high efficiency and low NO{sub x}. Quarterly report, 1 December 1994--28 February 28, 1995

    Energy Technology Data Exchange (ETDEWEB)

    Rajan, S. [Southern Illinois Univ., Carbondale, IL (United States)

    1995-12-31

    High efficiencies can be obtained from combined cycle power plants where fuel gas produced in a carbonizer is used to power the topping cycle turbines, while the residual char is burnt to raise steam for the bottoming Rankine cycle plant. Illinois coals are excellent fuels for these high efficiency power plants as the sulfur in the fuel gas is removed in the carbonization process by adding dolomite, thus producing a clean burning fuel gas. The residual char has essentially no volatiles, and is of low density. Because of these characteristics the char requires a longer residence time for efficient combustion. This research is directed towards improving the residence time of the char by pelletizing it with a waste coal, while at the same time reducing the sulfur dioxide emissions from the char combustion. During this quarter, extensive experimentation has been performed to determine the char-gob waste proportions necessary for forming pellets with desirable compression strength for feeding into the circulating fluidized bed combustor. Carbonizer char-gob coal pellets have been made with 5, 10 and 15 weight percent of cornstarch binder. Based on the test data presented, it is concluded that 10--15% weight percent of binder will be required when pelletizing char-gob coal waste mixtures containing 30-40 percent by weight of gob coal. During the next quarter, these pellets will be made in larger quantities and their combustion and emissions properties will be evaluated in a bench scale 4-inch diameter circulating fluidized bed combustor.

  17. Current status, between-year comparisons and maternal transfer of organohalogenated compounds (OHCs) in Arctic char (Salvelinus alpinus) from Bjørnøya, Svalbard (Norway)

    Energy Technology Data Exchange (ETDEWEB)

    Bytingsvik, J., E-mail: jenny.bytingsvik@akvaplan.niva.no [Akvaplan-niva AS, The Fram Centre, N-9296 Tromsø Norway (Norway); Frantzen, M. [Akvaplan-niva AS, The Fram Centre, N-9296 Tromsø Norway (Norway); Götsch, A.; Heimstad, E.S. [NILU (Norwegian Institute for Air Research), The Fram Centre, N-9296 Tromsø Norway (Norway); Christensen, G. [Akvaplan-niva AS, The Fram Centre, N-9296 Tromsø Norway (Norway); Evenset, A. [Akvaplan-niva AS, The Fram Centre, N-9296 Tromsø Norway (Norway); University of Tromsø, The Arctic University of Norway, Pb 6050 Langnes, N-9037 Tromsø (Norway)

    2015-07-15

    High levels of organohalogenated compounds (OHCs) have been found in Arctic char from Lake Ellasjøen at Bjørnøya (Svalbard, Norway) compared to char from other arctic lakes. The first aim of the study was to investigate the OHC status, contaminant profile, and partitioning of OHCs between muscle and ovary tissue in spawning female char from the high-polluted Lake Ellasjøen and the low-polluted Lake Laksvatn. The second aim was to investigate if OHC levels in muscle tissue have changed over time. Between-lake comparisons show that the muscle levels (lipid weight) of hexachlorobenzene (HCB), chlordanes (∑ CHLs), mirex, dichlorodiphenyltrichloroethanes (∑ DDTs) and polychlorinated biphenyls (∑ PCBs) were up to 36 times higher in char from Ellasjøen than in Laksvatn, and confirm that the char from Ellasjøen are still heavily exposed compared to char from neighboring lake. A higher proportion of persistent OHCs were found in Ellasjøen compared to Laksvatn, while the proportion of the less persistent OHCs was highest in Laksvatn. A between-year comparison of OHC levels (i.e., HCB, DDTs, PCBs) in female and male char shows higher levels of HCB in female char from Ellasjøen in 2009/2012 compared to in 1999/2001. No other between-year differences in OHC levels were found. Due to small study groups, findings associated with between-year differences in OHC levels should be interpreted with caution. OHCs accumulate in the lipid rich ovaries of spawning females, resulting in up to six times higher levels of OHCs in ovaries compared to in muscle (wet weight). The toxic equivalent (TEQ)-value for the dioxin-like PCBs (PCB-105 and -118) in ovaries of the Ellasjøen char exceeded levels associated with increased egg mortality in rainbow trout (Oncorhynchus mykiss). Hence, we suggest that future studies should focus on the reproductive health and performance abilities of the high-exposed population of char inhabiting Lake Ellasjøen. - Highlights: • Examine levels

  18. Two-pulse NMR techniques for studying proton-unpaired electron interactions in coals and chars

    Science.gov (United States)

    Barton, W. A.; Lynch, L. J.

    The time-domain NMR signals stimulated in solids by two-pulse sequences of the form 90°- τ- βφ, where β is the angle of rotation and φ the relative phase of the second pulse which is separated from the initial 90° pulse by a time τ, can be influenced by the presence of a second spin species and therefore, in principle, can yield information on the separate contributions, M2II and M2IS, of like- and unlike-spin interactions to the Van Vleck second moment M2I of the resonant spins. The validity of the standard operator formalism for predicting the transverse magnetization signals thus produced in homogeneous solids by the 90°- τ-90 φ° and 90°- τ-180 φ° ( φ = 0° and 90°) sequences is discussed and the effects of pulse duration are briefly outlined. The time-series expansions yielded by the operator formalism for these signals are reviewed with emphasis on the effects of unlike-spin interactions, and a useful difference signal is discussed. The potential for application of these two-pulse techniques to protons in heterogeneous solids such as coals, in which unpaired electrons constitute the second spin species, is considered and experimentally assessed. Semiquantitative estimates of M2IS are made for protons in diphenyl picryl hydrazyl (DPPH) and several coals and chars at room temperature from measurements of the amplitude of the 90°- τ-90° 0 ° transient signal at small τ and of the initial rate of attenuation of the 90°- τ-90 90°° solid echo with increasing τ. It is found that (i) organic radicals and paramagnetic ions produce relatively small M2IS values, a result which limits the usefulness of this approach to studying unpaired electron properties of coals and chars; (ii) the M2II values deduced from these results and calculations of M2I follow expected trends; and (iii) only specimens containing small particles of magnetically ordered material give rise to rapidly decaying time-domain signals and a well-defined 90°- τ-180 90°° spin

  19. SiteChar - Workflow for fit-for-purpose characterisation of CO2 storage sites in Europe

    NARCIS (Netherlands)

    Delprat-Jannaud, F.; Pearce, J.; Neele, F.; Akhurst, M.; Nielsen, C.; Mazurowski, M.; Lothe, A.; Volpi, V.; Brunsting, S.

    2014-01-01

    The FP7 SiteChar project has examined the entire site characterization chain, from the initial feasibility studies through to the final stage of application for a storage permit, on the basis of criteria defined by the relevant European legislation, highlighting important issues and recommendations

  20. Effects of rice husks and their chars from hydrothermal carbonization on the germination rate and root length of Lepidium sativum

    Science.gov (United States)

    Kern, Jürgen; Mukhina, Irina; Dicke, Christiane; Lanza, Giacomo; Kalderis, Dimitrios

    2015-04-01

    Currently, char substrates gain a lot of interest, since they are being discussed as a component in growing media, which may become one option for the replacement of peat. Among different thermal conversion processes of biomass hydrothermal carbonization (HTC) has been found to produce chars with similar acidic pH values like peat. The question however is, if these hydrochars, which may contain toxic phenolic compounds are suitable to be introduced as a new substitute for peat in horticulture. In this study rice husk were hydrothermally carbonized at 200° C for 6 hours, yielding in hydrochars containing organic contaminants such as phenols and furfurals, which may affect plants and soil organisms. We investigated potential toxic effects on the germination rate and the root length of cress salad (Lepidium sativum) in four fractions: i) soil control, ii) raw rice husk + soil, iii) unwashed rice char + soil and iv) acetone/water washed rice char + soil. It could be shown that phenols and furfurals, which were removed from the hydrochar after washing by 80 to 96% did not affect the germination rate and the root length of the cress plants. The lowest germination rate and root length were found in the soil control, the highest in the non-washed hydrochar treatment, indicating a fertilization effect and growth stimulation of cress salad by hydrochar. If this result can be confirmed for other target and non-target organisms in future studies, a new strategy for the production of growing media may be developed.

  1. Fuel, fire and heat: an experimental approach to highlight the potential of studying ash and char remains from archaelological contexts

    NARCIS (Netherlands)

    Braadbaart, F.; Poole, I.; Huisman, H.D.J.; Os, B. van

    2012-01-01

    As in traditional societies today ancient societies probably selected different fuels to meet specific heat requirements. Char and ash, the end products of fire, are often found in abundance in archaeological contexts. These end products can provide information regarding (i) the original fuel resour

  2. The development of nitrogen functionality in model chars during gasification in CO{sub 2} and O{sub 2}

    Energy Technology Data Exchange (ETDEWEB)

    Kapteijn, F.; Moulijn, J.A.; Matzner, S.; Boehm, H.P. [Delft University of Technology, Delft (Netherlands). Waterman Inst.

    1999-10-01

    The development of the nitrogen functionality of model chars as a function of burn-off for gasification in CO{sub 2} or in O{sub 2} has been studied by X-ray photoelectron spectroscopy (XPS). The type of carbon precursor (sucrose or phenolformaldehyde resin) and of nitrogen precursor (uracil, aniline or 3-hydroxypyridine), to synthesise the nitrogen doped model chars, did not have an influence on this development. The high-temperature chars (1373 K) exhibit N-functionalities attributed to pyridinic nitrogen, pyridones, and oxidic nitrogen species at the edges of the graphene structures and quaternary nitrogen incorporated in the graphene structure. With increasing burn-off levels, nitrogen accumulates in the char, especially during O{sub 2} gasification. A gradual transition from quaternary nitrogen to pyridine and pyridinic nitrogen is observed, due to the removal of surrounding carbon. In O{sub 2} this phenomenon is more pronounced than in CO{sub 2} gasification, and more pyridine is formed due to its association with carbon-oxygen functionalities. A schematic model is presented that accounts for the development of nitrogen functionalities and the nitrogen retention.

  3. Development of an advanced continuous mild gasification process for the production of coproducts. Task 4, System integration studies: Char upgrading

    Energy Technology Data Exchange (ETDEWEB)

    Jha, M.C.; McCormick, R.L.; Hogsett, R.F.; Rowe, R.M.; Anast, K.R.

    1991-12-01

    This document describes the results of Task 4 under which a 50 pound/hour char-to-carbon (CTC) process research unit (PRU) was designed in the second half of 1989, with construction completed in June 1990. The CTC PRU at Golden was operated for nearly one year during which 35 runs were completed for a total of nearly 800 hours of operation. Char methanation and carbon production reactor development activities are detailed in this report, as well as the results of integrated runs of the CTC process. Evaluation of the process and the carbon product produced is also included. It was concluded that carbon could be produced from mild gasification char utilizing the CTC process. Char methanation and membrane separation steps performed reasonably well and can scaled up with confidence. However, the novel directly heated reactor system for methane cracking did not work satisfactorily due to materials of construction and heat transfer problems, which adversely affected the quantity and quality of the carbon product. Alternative reactor designs are recommended.

  4. Slow pyrolysis of poultry litter and pine woody biomass: impact of chars and bio-oils on microbial growth.

    Science.gov (United States)

    Das, K C; Garcia-Perez, M; Bibens, B; Melear, N

    2008-06-01

    Accidental or prescribed fires in forests and in cultivated fields, as well as primitive charcoal production practices, are responsible for the release of large amounts of gases, char and condensable organic molecules into the environment. This paper describes the impact of condensable organic molecules and chars resulting from the slow pyrolysis of poultry litter, pine chips and pine pellets on the growth of microbial populations in soil and water. The proximate and elemental analyses as well as the content of proteins, cellulose, hemicellulose, lignin, and ash for each of these bio-materials are reported. The yields and some properties of char and condensable liquids are also documented. The behavior of microbial populations in soil and water is followed through respiration studies. It was found that biological activity was highest when aqueous fractions from poultry litter were applied in water. Cumulative oxygen consumption over a 120-h period was highest in the aqueous phases from poultry litter coarse fraction (1.82 mg/g). On average the oxygen consumption when oily fractions from poultry litter were applied represented 44 to 62% of that when aqueous fractions were applied. Pine chip and pine pellet derived liquids and chars produced respiration activity that were an order of magnitude lower than that of poultry litter liquid fractions. These results suggest that the growth observed is due to the effect of protein-derived molecules. PMID:18444073

  5. Comparison of high temperature chars of wheat straw and rice husk with respect to chemistry, morphology and reactivity

    DEFF Research Database (Denmark)

    Trubetskaya, Anna; Jensen, Peter Arendt; Jensen, Anker Degn;

    2016-01-01

    Fast pyrolysis of wheat straw and rice husk was carried out in an entrained flow reactor at hightemperatures(1000e1500) C. The collected char was analyzed using X-ray diffractometry, N2-adsorption,scanning electron microscopy, particle size analysis with CAMSIZER XT, 29Si and 13C solid-statenucle...

  6. Anadromous char as an alternate food choice to marine animals: A synthesis of Hg concentrations, population features and other influencing factors

    International Nuclear Information System (INIS)

    This study was conducted to confirm sporadic measurements made over the late 1970s to the early 1990s which determined that mercury (Hg) concentrations were low in anadromous char across Arctic and subarctic Canada including northern Québec and Labrador. Over 2004–2013, anadromous char populations across northern Canada were investigated at 20 sites for Hg concentrations and life history characteristics. Hg concentrations were extremely low in anadromous char muscle, typically < 0.05 μg/g (wet weight) and, at each location, generally increased with fish length, age and nitrogen isotope (δ15N) ratio and decreased with condition factor and %lipid; correlations with carbon isotope (δ13C) ratio were inconsistent. Location and year were significant variables influencing Hg concentrations over the study area; longitude and latitude also were significant influencing variables. Char length, weight, age, condition factor and lipid content explained additional variance. A tendency towards higher Hg concentrations with increasing latitude may be partially related to decreasing growth of char towards the north. However, Hg concentrations in char were positively correlated with growth rates suggesting that Hg concentrations in char also were higher in the more productive study areas, including to the west where mainland riverine inputs of terrestrial carbon, nutrients, and Hg were greater. The data base for assessing time trends in char was limited by the small number of years investigated at most locations, variable fish size across years, small sample size, etc. Where temporal trends were detected, they were of increase on the long term (1970s, 1980s or early 1990s to the present) but of decrease on the short term (early 2000s to present) with Nain (Labrador) showing the converse pattern. Higher Hg concentrations were also related to lower condition factor and cooler springs. Hg concentrations in anadromous char are compared with other terrestrial, aquatic and marine

  7. Oxy-fuel combustion kinetics and morphology of coal chars obtained in N2 and CO2 atmospheres in an entrained flow reactor

    International Nuclear Information System (INIS)

    Highlights: ►Char reactivity in oxy-fuel conditions is essential for industrial scale designing. ► Kinetics of coal chars obtained in N2 and CO2 were determined under 30%O2–70%CO2. ► The best model for describing the oxy-fuel combustion of coal chars was the RPM. ► CO2 chars showed higher volatile yield and slightly lower reactivity than N2 chars. -- Abstract: The thermal reactivity and kinetics of four coal chars (HVN, UM, SAB and BA) in an oxy-fuel combustion atmosphere (30%O2–70%CO2) were studied using a thermobalance. The coal chars were obtained by devolatilization in an entrained flow reactor (EFR) at 1000 °C for 2.5 s under 100% N2 and CO2 atmospheres. The reactivity tests were carried out by isothermal thermogravimetric analysis at different temperatures in a kinetically controlled regime. Three nth-order representative gas–solid models – the volumetric model (VM), the grain model (GM) and the random pore model (RPM) – were employed in order to describe the reactive behaviour of the chars during oxy-fuel combustion. From these models, the kinetic parameters were determined. The RPM model was found to be the best for describing the reactivity of the HVN, UM and BA chars, while VM was the model that best described the reactivity of the SAB char. The reactivities of the chars obtained in N2 and CO2 in an oxy-fuel combustion atmosphere with 30% of oxygen were compared using the kinetic parameters, but no differences were observed between the two devolatilization atmospheres. The apparent volatile yield after the coal devolatilization under CO2 in the EFR was greater than under N2 for all the coals studied. According to the scanning electron microscopy (SEM) images of the chars, those obtained in the CO2 atmosphere experienced a greater degree of swelling, some particles showing partially reacted surfaces indicative of reaction between the char and CO2.

  8. Anadromous char as an alternate food choice to marine animals: A synthesis of Hg concentrations, population features and other influencing factors

    Energy Technology Data Exchange (ETDEWEB)

    Evans, Marlene S., E-mail: marlene.evans@ec.gc.ca [Environment Canada, Water Science and Technology Directorate, 11 Innovation Blvd., Saskatoon SK S7N 3H5 (Canada); Muir, Derek C.G. [Environment Canada, Water Science and Technology Directorate, 867 Lakeshore Rd., Burlington, ON L7R 4A6 (Canada); Keating, Jonathan [Environment Canada, Water Science and Technology Directorate, 11 Innovation Blvd., Saskatoon SK S7N 3H5 (Canada); Wang, Xiaowa [Environment Canada, Water Science and Technology Directorate, 867 Lakeshore Rd., Burlington, ON L7R 4A6 (Canada)

    2015-03-15

    This study was conducted to confirm sporadic measurements made over the late 1970s to the early 1990s which determined that mercury (Hg) concentrations were low in anadromous char across Arctic and subarctic Canada including northern Québec and Labrador. Over 2004–2013, anadromous char populations across northern Canada were investigated at 20 sites for Hg concentrations and life history characteristics. Hg concentrations were extremely low in anadromous char muscle, typically < 0.05 μg/g (wet weight) and, at each location, generally increased with fish length, age and nitrogen isotope (δ{sup 15}N) ratio and decreased with condition factor and %lipid; correlations with carbon isotope (δ{sup 13}C) ratio were inconsistent. Location and year were significant variables influencing Hg concentrations over the study area; longitude and latitude also were significant influencing variables. Char length, weight, age, condition factor and lipid content explained additional variance. A tendency towards higher Hg concentrations with increasing latitude may be partially related to decreasing growth of char towards the north. However, Hg concentrations in char were positively correlated with growth rates suggesting that Hg concentrations in char also were higher in the more productive study areas, including to the west where mainland riverine inputs of terrestrial carbon, nutrients, and Hg were greater. The data base for assessing time trends in char was limited by the small number of years investigated at most locations, variable fish size across years, small sample size, etc. Where temporal trends were detected, they were of increase on the long term (1970s, 1980s or early 1990s to the present) but of decrease on the short term (early 2000s to present) with Nain (Labrador) showing the converse pattern. Higher Hg concentrations were also related to lower condition factor and cooler springs. Hg concentrations in anadromous char are compared with other terrestrial, aquatic

  9. Evaluation of charred porous polymers as a method of storm water pollution prevention for shipyards

    Energy Technology Data Exchange (ETDEWEB)

    Clark, G.E.

    1998-08-01

    Most shipyards have viable Best Management Practices (BMPs) in place to mitigate the transport of heavy metals to surface waters by storm water. Despite aggressive efforts to control storm water, shipyards have come under increased regulatory pressure to further reduce concentrations of heavy metals, such as copper and nickel, in storm water discharges. The tightening of regulatory requirements warrants research into additional BMPs. The objectives of this research project were to: (1) determine the feasibility of placing a replaceable cartridge of adsorbent material within a storm water collection system; and (2) evaluate two commercially available charred porous polymer adsorbents for the removal of heavy metals from storm water. The results indicated that there are commercially available storm water treatment components which could be adapted to house a cartridge of porous adsorbent material.

  10. Catalytic gasification of chars and carbon: Annual report, October 1, 1985-September 30, 1986

    Energy Technology Data Exchange (ETDEWEB)

    Heinemann, H.

    1986-09-01

    This program is designed to study the basic chemistry of the reaction of carbonaceous materials with water in the presence of catalysts to produce hydrocarbons and/or synthesis gas. Relatively low temperatures are being used. Earlier work has shown that a combination of KOH and a transition metal oxide, such as NiO, constitutes catalysts superior to either component alone. It is an objective of the present task to identify the optimum ratio of the components and to determine the existence and composition of a potential catalytic compound, e.g., a potassium nickelate. The applicability of the reactions thus far studied with graphite to char, coke and possibly coal will be investigated. Improvements in kinetics will be sought and the effect of added gases, such as H/sub 2/S, CO and O/sub 2/ will be researched. 9 refs., 12 figs., 1 tab.

  11. Characteristics of flame spread over the surface of charring solid combustibles at high altitude

    Institute of Scientific and Technical Information of China (English)

    LI Jie; JI Jie; ZHANG Ying; SUN JinHua

    2009-01-01

    To explore the characteristics of flame spread over the surface of charring solid combustibles at high altitude, the whitewood with uniform texture was chosen to conduct a series of experiments in Lhasa and Hefei, with altitude of 3658 m and 50 m respectively. Several parameters, including the flame height, flame spread rate, flame temperature, surface temperature, were measured on samples with different width and inclinations. A quantitative analysis of flame spread characteristics over sample surface at high altitude was performed. Results showed that, in the environment of lower pressure and oxygen concentration at high altitude, the flame height and flame spread rate over sample surface decreased, but the flame temperature increased slightly. However, with increasing of sample width, the relative difference between the flame spread rates at different altitudes decreased.

  12. Physical and chemical limnology of Char Lake, Cornwallis Island (75 degrees N lat. )

    Energy Technology Data Exchange (ETDEWEB)

    Schindler, D.W.; Welch, H.E.; Kalff, J.; Brunskill, G.J.; Kritsch, N.

    1974-01-01

    Seasonal data for several physical and chemical variables in Char Lake are given. Annual cycles of major solutes are influenced primarily by freeze-thaw cycles. Concentrations of most substances are increased by freezing-out during the winter. Because the lake does not circulate during maximum spring meltwater flow, this freezing-out maintains concentrations in the lake above those in inflow streams. Concentrations of phosphorus and nitrogen in the lake are low throughout the year. Precipitation contains little phosphorus or nitrogen. Input of phosphorus and nitrogen are calculated to be 0.016 and 0.314 grams/square meter, respectively. Retention of nutrients by the lake is lower than in temperate regions, although still quite efficient. With the exception of silica, return of ions from the sediments during winter was found to be negligible. Disturbance of one inflow stream due to airstrip construction caused great increases in concentrations of nitrogen, silica, chloride, sulfate, and bicarbonate in the stream.

  13. ["Raw and charred flesh": the experience of burned women in Northeast Brazil].

    Science.gov (United States)

    Arruda, Cristiani Nobre de; Braide, Andrea Stopglia Guedes; Nations, Marilyn

    2014-10-01

    In Northeast Brazil, death from burns is a widespread, pervasive threat to poor women. This anthropological study describes the experience of personal suffering among female burn patients. In 2009, six "information-rich" cases were investigated at the Burn Center in Fortaleza, Ceará State, Brazil. Open ethnographic interviews with key informants, narratives of lived experiences, and participant observation at the clinic and patients' home were conducted. The methods included content analysis, systems of signs, meanings, and actions, and contextualized semantic interpretation. The emerging metaphors are embued with the cultural meaning of "monstrosity" and gender violence by fire - inscribed mercilessly in the woman's body. "Accidents" caused by flammable liquids (alcohol) hide the cruel reality of "raw and charred flesh". The scars can disfigure the victims as "non-persons", destroying their moral reputation and leading to social rejection. In the Brazilian Northeast, the social vulnerability caused by sequelae from burns demands a policy for humanized care. PMID:25388309

  14. Crystallographic Oxide Phase Identification of Char Deposits Obtained from Space Shuttle Columbia Window Debris

    Science.gov (United States)

    Olivas, J. D.; Wright, M. C.; Christoffersen, R.; Cone, D. M.; McDanels, S. J.

    2009-01-01

    Analyzing the remains of Space Shuttle Columbia has proven technically beneficial years after the vehicle breakup. This investigation focused on charred deposits on fragments of Columbia overhead windowpanes. Results were unexpected relative to the engineering understanding of material performance in a reentry environment. The TEM analysis demonstrated that the oxides of aluminum and titanium mixed with silicon oxides to preserve a history of thermal conditions to which portions of the vehicle were exposed. The presence of Ti during the beginning of the deposition process, along with the thermodynamic phase precipitation upon cool down, indicate that temperatures well above the Ti melt point were experienced. The stratified observations implied that additional exothermic reaction, expectedly metal combustion of a Ti structure, had to be present for oxide formation. Results are significant for aerospace vehicles where thermal protection system (TPS) breaches cause substructures to be in direct path with the reentry plasma. 1

  15. Determination of reactivity parameters of model carbons, cokes and flame-chars

    DEFF Research Database (Denmark)

    Sørensen, Lasse Holst; Gjernes, Erik; Jessen, Thomas;

    1996-01-01

    and activation energy in oxygen are estimated for each sample over a 100 K temperature range (cases vary from 573 to 885 K) and a maximum oxygen partial pressure range of 0.01-1 bar. For the different fuel samples reaction orders range fromn =0.65 to 0.78, and global activation energies are found in the narrow...... range of 130-133 kJ/mol. For Carboxen n=0.91 and E=146 kJ/mol. The reactivity differences between the coal chars are proposed mainly due to variations in the physical structure. Over the pressure-temperature domain examined reactivity varies considerably, but the structural profile is approximately...... the reactivity decreases by a factor ranging from 2 to 5. These results emphasize the importance of a sound understanding of the structural evolution of a given sample in evaluating and using kinetic parameters. Global kinetic parameters are obtained by isolating kinetics from structural effects. A flexible...

  16. Utilization of oil palm tree residues to produce bio-oil and bio-char via pyrolysis

    International Nuclear Information System (INIS)

    Highlights: • About 14.72% of the total landmass in Malaysia was used for oil palm plantations. • Oil palm tree residues were pyrolyzed to produce bio-oil and bio-char. • The process was performed at a temperature of 500 °C and reaction time of 60 min. • Characterization of the products was performed. - Abstract: Oil palm tree residues are a rich biomass resource in Malaysia, and it is therefore very important that they be utilized for more beneficial purposes, particularly in the context of the development of biofuels. This paper described the possibility of utilizing oil palm tree residues as biofuels by producing bio-oil and bio-char via pyrolysis. The process was performed in a fixed-bed reactor at a temperature of 500 °C, a nitrogen flow rate of 2 L/min and a reaction time of 60 min. The physical and chemical properties of the products, which are important for biofuel testing, were then characterized. The results showed that the yields of the bio-oil and bio-char obtained from different residues varied within the ranges of 16.58–43.50 wt% and 28.63–36.75 wt%, respectively. The variations in the yields resulted from differences in the relative amounts of cellulose, hemicellulose, lignin, volatiles, fixed carbon, and ash in the samples. The energy density of the bio-char was found to be higher than that of the bio-oil. The highest energy density of the bio-char was obtained from a palm leaf sample (23.32 MJ/kg), while that of the bio-oil was obtained from a frond sample (15.41 MJ/kg)

  17. Corrosion of iron-base alloys by coal char at 871/sup 0/ and 982/sup 0/C

    Energy Technology Data Exchange (ETDEWEB)

    Gordon, B.A.

    1978-03-01

    The high pressures and temperatures required for the processing of coal lead to accelerated corrosion of gasifier components by oxygen and sulfur present in the gas phase. Coal char, the solid byproduct of coal processing, contains sufficient inorganic sulfur to result in internal attack of the alloys composing the gasifier components. The role of coal char in coal processing and of thermodynamics in gas phase corrosion are discussed. Experiments were performed to determine whether CaSO/sub 4/ or FeS are responsible for the internal attack on Fe--Cr--Al and Fe--Cr--Ni alloys observed under conditions of both high oxygen partial pressure and 982/sup 0/C and low oxygen partial pressure and 982/sup 0/C. Exposure at 871/sup 0/C resulted in virtually no attack from coal char and FeS and very slight attack from CaSO/sub 4/. The morphologies and rates of attack indicate that at very low oxygen partial pressures (about 10/sup -19/ atmosphere) the presence of CaSO/sub 4/ can result in internal sulfidation whereas at higher oxygen partial pressures (about 10/sup -15/ atmosphere), the presence of FeS can result in internal sulfidation. Comparison of these results with those actually observed from coal char at 982/sup 0/C indicate that FeS is primarily responsible for attack by coal char but that CaSO/sub 4/ can also result in such attack although the overall mechanism and rate of attack may be different.

  18. Population connectivity: dam migration mitigations and contemporary site fidelity in arctic char

    Directory of Open Access Journals (Sweden)

    Heggenes Jan

    2011-07-01

    Full Text Available Abstract Background Animal feeding and spawning migrations may be limited by physical barriers and behavioral interactions. Dam constructions (e.g. hydropower commonly include gateways for fish migrations to sustain ecological connectivity. Relative genetic impacts of fish passage devices versus natural processes (e.g. hybrid inferiority are, however, rarely studied. We examined genetic (i.e. microsatellite population connectivity of highly migrating lake-dwelling Arctic char (Salvelinus alpinus, introduced 20 generations ago, across and within two subalpine lakes separated by a dam with a subterranean tunnel and spill gates after 7 generations. Due to water flow regime, the time window for fish migration is highly restricted. Results Char populations, with similar genetic structuring and diversity observed across and within lakes, were admixed across the dam with fishways during feeding. For spawning, however, statistically significant, but very low population differentiation (θ; 0.002 - 0.013 was found in nine out of ten reproductive site comparisons, reflecting interactions between extensive migration (mean first generation (F0 = 10.8% and initial site fidelity. Simulations indicated that genetic drift among relatively small effective populations (mean Ne = 62 may have caused the observed contemporary differentiation. Novel Bayesian analyses indicated mean contributions of 71% F0 population hybrids in spawning populations, of which 76% had maternal or paternal native origin. Conclusions Ecological connectivity between lakes separated by a dam has been retained through construction of fishways for feeding migration. Considerable survival and homing to ancestral spawning sites in hybrid progeny was documented. Population differentiation despite preceding admixture is likely caused by contemporary reduced reproductive fitness of population hybrids. The study documents the beginning stages of population divergence among spatial aggregations with

  19. An autopsy case of a charred body which committed suicide after arson.

    Science.gov (United States)

    Tatsumi, S; Noda, H; Sugiyama, S

    2000-08-01

    A severely burned body was found lying on its right side at the scene of the fire in a 2-story wooden apartment house. The presence of a ligature (an electrical cord) running horizontally around the neck aroused suspicion of arson after homicidal strangulation (murder-arson). The entire body was severely burned and partly charred. The head and neck were severely charred, and the left temporal bone had been consumed exposing the brain. Around the neck was looped an electrical cord, which ran horizontally and canted downward toward the nape, leaving a furrow resulting from the knot being tightened up. No other injuries or pathologic lesions suggestive of the cause of death were noted. No drug, poison or alcohol was detectable in the blood or urine. The peculiar method of making a noose of the ligature around the neck is called clove hitch, which makes the noose tighten further with increased load. The fallen curtain rod had a bend with an acute angle, which was considered to have been the point of suspension in hanging. In addition, a lighter was found under the corpse, which was presumably used to ignite the gasoline that the deceased sprinkled. We speculate, therefore, that the deceased hanged himself by placing the electrical cord around his neck (by clove hitch), suspending it from the curtain rod, sprinkling gasoline in his room, igniting it with a lighter, executing suicidal hanging after the start of the fire. Probably the body was wrapped in flames while dangling, then fell to the floor together with the collapsing curtain rod. PMID:12935453

  20. Chemical and Isotopic Thresholds in Charring: Implications for the Interpretation of Charcoal Mass and Isotopic Data

    Science.gov (United States)

    Pyle, L.; Hockaday, W. C.; Boutton, T. W.; Zygourakis, K.; Kinney, T.; Masiello, C. A.

    2014-12-01

    Charcoal plays a significant role in the long-term carbon cycle and its use as a soil amendment is becoming a viable carbon sequestration strategy (biochar). One challenge in this research area has been comparing results between studies in part due to the diversity of lab and field production conditions. Although the highest treatment temperature (HTT) is often used to describe pyrolysis conditions, several studies have shown that length of time at the highest temperature can also cause changes to the physicochemical qualities of charcoal and ignoring this effect may introduce inter-comparison problems. Addressing this issue becomes especially important in the discussion of optimizing biochar for soil remediation and carbon sequestration, and in discussions of charcoal use in reconstructing past fire regimes, as increasing time at temperature may cause changes in charcoal properties similar to the changes caused by increasing HTT. Here we introduce a formal definition of charring intensity (CI) to more accurately characterize pyrolysis, and we document variation in this property with pyrolysis temperature and reaction duration. We found two types of responses to CI: either a linear or a threshold relationship. We show that a threshold exists where %C, %N and δ15N begin exhibiting large changes, and this CI threshold co-occurred with an increase in charcoal aromaticity. Mass yield decreased linearly with charring intensity and carbon isotopes did not change from original biomass values in our controlled laboratory experiments. Analysis of these data shows that pyrolysis parameters should be defined in the literature as a combination of temperature and duration conditions, and that biomass that has undergone pyrolysis may be influencing soil organic nitrogen. Additionally, the lack of alteration in carbon isotopes across our matrix supports the efficacy of using pyrolyzed material for archaeological reconstructions.

  1. Mechanistic understanding of tetracycline sorption on waste tire powder and its chars as affected by Cu2+ and pH

    International Nuclear Information System (INIS)

    The sorption characteristics of tetracycline (TC) by waste tire powder and its chars were investigated to explore the potential of using waste tires as effective sorbents for removal of TC from aqueous solution. Naphthalene (NAPH), a typical hydrophobic organic compound, was selected as asorbate for comparison. TC displayed much lower sorption affinity to tire powder than NAPH. However, it exhibited similar adsorption affinity as NAPH on the pyrolyzed tire chars, which was mainly attributed to π-π electron-donor–acceptor interactions of TC with the graphite surface of chars. TC and Cu2+ could mutually facilitate the sorption of each other on both tire powder and pyrolyzed chars in a wide pH range. This could be explained by the metallic complexation and/or surface-bridging mechanisms (i.e., Cu- or TC-bridging). However, Cu2+ and NAPH depressed the sorption of each other on tire powder and displayed negligible impact to each other on the highly pyrolyzed chars. -- Graphical abstract: Conceptual illustration of the effects of Cu2+ on the sorption of tetracycline (TC) and naphthalene (NAPH) on tire powder (TP) and pyrolytic char (C800). Highlights: •Tire chars could be effective sorbents for tetracycline wastewater treatment. •Tetracycline and Cu2+ facilitate sorption of each other on tire sorbents in a wide pHs. •Naphthalene and Cu2+ depressed the sorption of each other on tire powder. •Naphthalene and Cu2+ displayed negligible effect to each other on carbonized chars. -- Cu2+ exhibits opposite impacts on the sorption of tetracycline on waste tire powder and its chars

  2. The role of nano-sized manganese coatings on bone char in removing arsenic(V) from solution: Implications for permeable reactive barrier technologies.

    Science.gov (United States)

    Liu, Jing; He, Lile; Dong, Faqin; Hudson-Edwards, Karen A

    2016-06-01

    Although the removal of arsenic(V) (As(V)) from solution can be improved by forming metal-bearing coatings on solid media, there has been no research to date examining the relationship between the coating and As(V) sorption performance. Manganese-coated bone char samples with varying concentrations of Mn were created to investigate the adsorption and desorption of As(V) using batch and column experiments. Breakthrough curves were obtained by fitting the Convection-Diffusion Equation (CDE), and retardation factors were used to quantify the effects of the Mn coatings on the retention of As(V). Uncoated bone char has a higher retention factor (44.7) than bone char with 0.465 mg/g of Mn (22.0), but bone char samples with between 5.02 mg/g and 14.5 mg/g Mn have significantly higher retention factors (56.8-246). The relationship between retardation factor (Y) and Mn concentration (X) is Y = 15.1 X + 19.8. Between 0.2% and 0.6% of the sorbed As is desorbed from the Mn-coated bone char at an initial pH value of 4, compared to 30% from the uncoated bone char. The ability of the Mn-coated bone char to neutralize solutions increases with increased amounts of Mn on the char. The results suggest that using Mn-coated bone char in Permeable Reactive Barriers would be an effective method for remediating As(V)-bearing solutions such as acid mine drainage. PMID:27016809

  3. Optimisation of slow-pyrolysis process conditions to maximise char yield and heavy metal adsorption of biochar produced from different feedstocks.

    Science.gov (United States)

    Hodgson, E; Lewys-James, A; Rao Ravella, S; Thomas-Jones, S; Perkins, W; Gallagher, J

    2016-08-01

    The objective of this work was to identify biomass feedstocks and optimum pyrolysis process conditions to produce a biochar capable of adsorbing metals from polluted groundwater. Taguchi experimental design was used to determine the effects of slow-pyrolysis process conditions on char yield and zinc adsorption. Treatments were repeated using six candidate feedstocks (Lolium perenne, Lolium perenne fibre, Miscanthus x giganteus, Salix viminalis, Fraxinus excelsior and Picea sitchensis) and the resultant chars were tested for metal adsorption performance. Chars produced from L. perenne and its extracted fibre displayed the greatest zinc adsorption performance and removed 83.27-92.96% respectively. Optimum process conditions in terms of both char yield and zinc adsorption performance were achieved from slow-pyrolysis at 300°C for 2h using a feedstock with a particle size of less than 1mm. PMID:27179953

  4. Environmental Impacts of the Production and Application of Biochar - EuroChar Project

    Science.gov (United States)

    Rack, Mireille; Woods, Jeremy

    2014-05-01

    One of the potential benefits of biochar is carbon sequestration. To determine the overall net sequestration potential it is important to analyse the full supply chain, assessing both the direct and indirect emissions associated with the production and application of biochar. However, it is essential to also incorporate additional environmental impact categories to ensure the assessment of a more complete environmental impact profile. This paper uses a full life-cycle assessment (LCA) methodology to evaluate the results from the EuroChar, 'biochar for carbon sequestration and large-scale removal of GHG from the atmosphere', project. This EU Seventh Framework Programme project aims to investigate and reduce uncertainties around the impacts of, and opportunities for, biochar, and in particular explore possible pathways for its introduction into modern agricultural systems in Europe. The LCA methodology, according to the ISO standards, is applied to the project-specific supply chains to analyse the environmental impacts of biochar production and application. Two conversion technologies for the production of biochar are assessed, gasification and hydrothermal carbonization (HTC), in order to provide conversion efficiencies and emission factors for the biochar production component of the supply chain. The selected feedstocks include those derived from waste residues and dedicated crops. For the end use stage, various forms and methods for biochar application are considered. In addition to the Global Warming Potential category, other environmental impact categories are also included in the analysis. The resulting 'feedstock * conversion technology' matrix provides nine pathways for the production and application of biochar, which are applied as a representative basis for the scenario modelling. These scenarios have been developed in order to assess the feedstock and land availability in Europe for the production and application of biochar and to give an order of

  5. Removal of Methylene Blue Dye from Synthetic Wastewater with Bone Char

    Directory of Open Access Journals (Sweden)

    Gh Ghanizadeh

    2009-09-01

    Full Text Available "n "n "nBackgrounds and Objectives: Dyes  are  organic  materials  with  complex structures, toxic,  carcinogenic, teratogenic,nonbiodegredable properties and!the most!important pollutants of textile industrial wastewaters. The goal of this study was to survey the feasibility application of bone char (BC as a sorbent for the  of methylene blue (MB from synthetic wastewater.The sub goals of the research!were to determine!the adsorption isotherm, !effects of primary concentration of dye, adsorbent!dose, contact!time, and pH for the adsorption of MB with BC."nMaterials and Methods: BC was prepared under laboratory conditions by using of electrical furnace at 400°C for 2h. The prepared BC was crushed and pulverized by standard ASTM sieves with range of 10-16mesh(1.18-2mm.The  chemical composition  and  solid  structure  of BC was  analyzed using X-ray diffraction(XRD and  scanning  electronic  microscopy (SEM. Measurement  of  the surface area was carried out by N2 gas via BET isotherm and Belsorb software. The concentration of dye was measured by photometric!method (663nm."nResults: Predominant!compositionof BC is calcium hydroxyl apatite (Ca5 (PO43OH with 14m2/g surface area. The results of this study showed that increasing of primary concentration of dye, adsorbent dose and pH (5 to12 would lead to increasing of adsorption/removal of MB dye.Equilibration of dye adsorption was reached at lapse of 2h andoptimum pH for adsorption of MB with BC found in the rage of 8.5-12.Adsorption of MB witht BC complies witht freundlich isotherm(R2:0.99."nConclusion: Bone char is a cheap component that can be used as an adsorbent in water and wastewater treatment. Based on optimum pH of 8.5-12 found for the removal of MB and the fact that many of textile!industrial wastewaters have an alkaline pH, this adsorbent can be!used for the removal of dyes from these wastewaters.

  6. How do the poor handle money? What do the financial diaries of char dwellers tell us about financial inclusion?

    Directory of Open Access Journals (Sweden)

    Kuntala Lahiri-Dutt

    2013-05-01

    Full Text Available Derived from livelihoods surveys and ethnographic material about people living on the chars, or river islands, in deltaic lower Bengal, this paper illustrates the complex, diverse and ingenious ways that the poor manage money. These islands constitute some of the most vulnerable housing locations of some of the poorest communities; state services and facilities do not reach the chars because they are not listed as land in revenue records. It demonstrates that the poor live in a diverse economy where community spirit, family assistance and trust play roles equally important to markets. In doing so, it puts forth a grounded-in-the-field, evidence-based, critique of the slogan ‘financial inclusion’ that has gained prominence in recent years.

  7. A CFD approach on the effect of particle size on char entrainment in bubbling fluidised bed reactors

    International Nuclear Information System (INIS)

    The fluid - particle interaction inside a 41.7 mg s-1 fluidised bed reactor is modelled. Three char particles of sizes 500 μm, 250 μm, and 100 μm are injected into the fluidised bed and the momentum transport from the fluidising gas and fluidised sand is modelled. Due to the fluidising conditions and reactor design the char particles will either be entrained from the reactor or remain inside the bubbling bed. The particle size is the factor that differentiates the particle motion inside the reactor and their efficient entrainment out of it. A 3-Dimensional simulation has been performed with a completele revised momentum transport model for bubble three-phase flow according to the literature as an extension to the commercial finite volume code FLUENT 6.2.

  8. Combustion of char-coal waste pellets for high efficiency and low NO{sub x}. Technical report, September 1--November 30, 1994

    Energy Technology Data Exchange (ETDEWEB)

    Rajan, S. [Southern Illinois Univ., Carbondale, IL (United States)

    1994-12-31

    Illinois coals are prime candidates for use in Integrated Gasification Combined Cycle (IGCC) plants because of their high volatility and good char reactivity. In these plants, partial gasification of the coal in the presence of limestone eliminates the major portion of the sulfur species in the product gases, which are used as fuel for the topping cycle. The char produced is high in ash content, the major portion of which is calcium sulfide. It is also low in volatiles and of low density, compared to the parent coal. The economic success of the gasification route depends on the subsequent utilization of the residual char for raising steam for use in a Rankine cycle bottoming plant and/or preheating the air to the gasifier. Fluidized bed combustion of the char appears an attractive way of utilizing the char. Areas of concern in the fluidized bed combustion of the high ash, low volatility char are: attainment of high carbon conversion efficiencies; reduction of oxides of nitrogen emissions; reduction/elimination of corrosive chlorine species; reduction/elimination of sodium and other alkali species; and efficient usage of the calcium present in the ash to reduce sulfur compounds. The aim of the present project is to investigate ways of improving the carbon conversion efficiency, sulfur capture efficiency and NO{sub x} reduction during the fluidized bed combustion by pelletizing the low density char with coal and coal wastes using cornstarch or wood lignin as binder. During this first quarter, the parent coals and the chars to be tested have been analyzed. Particle size distributions have been measured. Sample pellets have been made evaluation of their properties.

  9. Arctic char - friend or foe?: Climate driven seasonal variation in competitive impact of Arcticchar (Salvelinus alpinus L) on brown trout (Salmo truttaence L)

    OpenAIRE

    Ulvan, Eva Marita

    2010-01-01

    Here I test for climate driven seasonal effects on competition in lakes using brown trout (Salmo trutta L.) and Arctic char (Salvelinus alpinus L.) as model organisms. Winter and summer brown trout consumption rates were estimated by 1374 Cs tracer methodology using brown trout sampled in  allopatric (brown trout) and 10 sympatric (brown trout/Arctic char) lakes, located along an altitudinal gradient in central Scandinavia. Lake catchment area  vegetation properties ranged from southern borea...

  10. Pyrolysis-GC/MS of charred purified condensed tannin: towards identification of tannin-derived black carbon in environmental samples

    Science.gov (United States)

    Kaal, Joeri; Nierop, Klaas G. J.; Kraal, Peter; Preston, Caroline M.

    2010-05-01

    Tannins account for a significant proportion of plant biomass and are therefore a possible source of Black C in the charred remains from wildfires. Nonetheless, in contrast with other major biocomponents such as lignin and cellulose, the thermal degradation of tannins has not been investigated in laboratory charring experiments. We used pyrolysis-GC/MS to investigate the effects of furnace charring (30 min at fixed temperatures up to 600 °C under limited oxygen supply) on the degradation of pure condensed tannin (CT) isolated from Corsican pine (Pinus nigra) needles. The experiments showed a rapid loss (at 300 °C and higher) of the pyrogallol moieties of the B-ring of prodelphinidin-type CT, due to dehydroxylation. The relative abundance of catechols (from procyanidin-type CT) decreased at 350 °C and higher temperatures. This led to the formation of phenols that were strongly enriched between 300 and 400 °C. At higher temperatures, further dehydroxylation caused a decline in contributions of phenols producing a series of monocyclic aromatics ((alkyl)benzenes) and condensation of aromatics produced polycyclic aromatic hydrocarbons (PAHs), i.e. the typical pyrolysis fingerprint of strongly charred biomass. We conclude that (i) the thermal degradation of CT can be successfully monitored by pyrolysis-GC/MS, (ii) thermal degradation of CT is characterized by dehydroxylation of phenolic groups and condensation of aromatics that increase with temperature and (iii) CT-derived Black C may be recognized by catechol enrichments at low temperatures and possibly (relative) abundance of phenol and biphenyl at higher levels of thermal breakdown. Applying the same method to natural charcoal from gorse bushfires indicated that pyrolysis-GC/MS fingerprinting may allow for tannin identification in environmental Black C samples.

  11. Predictive Method for Correct Identification of Archaeological Charred Grape Seeds: Support for Advances in Knowledge of Grape Domestication Process.

    Directory of Open Access Journals (Sweden)

    Mariano Ucchesu

    Full Text Available The identification of archaeological charred grape seeds is a difficult task due to the alteration of the morphological seeds shape. In archaeobotanical studies, for the correct discrimination between Vitis vinifera subsp. sylvestris and Vitis vinifera subsp. vinifera grape seeds it is very important to understand the history and origin of the domesticated grapevine. In this work, different carbonisation experiments were carried out using a hearth to reproduce the same burning conditions that occurred in archaeological contexts. In addition, several carbonisation trials on modern wild and cultivated grape seeds were performed using a muffle furnace. For comparison with archaeological materials, modern grape seed samples were obtained using seven different temperatures of carbonisation ranging between 180 and 340ºC for 120 min. Analysing the grape seed size and shape by computer vision techniques, and applying the stepwise linear discriminant analysis (LDA method, discrimination of the wild from the cultivated charred grape seeds was possible. An overall correct classification of 93.3% was achieved. Applying the same statistical procedure to compare modern charred with archaeological grape seeds, found in Sardinia and dating back to the Early Bronze Age (2017-1751 2σ cal. BC, allowed 75.0% of the cases to be identified as wild grape. The proposed method proved to be a useful and effective procedure in identifying, with high accuracy, the charred grape seeds found in archaeological sites. Moreover, it may be considered valid support for advances in the knowledge and comprehension of viticulture adoption and the grape domestication process. The same methodology may also be successful when applied to other plant remains, and provide important information about the history of domesticated plants.

  12. Predictive Method for Correct Identification of Archaeological Charred Grape Seeds: Support for Advances in Knowledge of Grape Domestication Process

    OpenAIRE

    Ucchesu, Mariano; Orrù, Martino; Grillo, Oscar; Venora, Gianfranco; Paglietti, Giacomo; Ardu, Andrea; Bacchetta, Gianluigi

    2016-01-01

    The identification of archaeological charred grape seeds is a difficult task due to the alteration of the morphological seeds shape. In archaeobotanical studies, for the correct discrimination between Vitis vinifera subsp. sylvestris and Vitis vinifera subsp. vinifera grape seeds it is very important to understand the history and origin of the domesticated grapevine. In this work, different carbonisation experiments were carried out using a hearth to reproduce the same burning conditions that...

  13. Effects of catalytic mineral matter CO/CO[sub 2] ratio on temperature and burning time for char combustion

    Energy Technology Data Exchange (ETDEWEB)

    Longwell, J.P.; Sarofim, A.F.; Tognotti, L.; Du, Zhiyou.

    1989-01-01

    The temperature of a char particle burning in an oxygen containing atmosphere is the product of a strongly coupled balance between particle size and physical properties, heat transfer from the particle, surface reactivity, CO/CO[sub 2] ratio and gas phase diffusion in the surrounding boundary layer and within the particle. The heat released by formation Of CO[sub 2] is a factor of 3.5 higher than for CO so the temperature of a particle will depend strongly on the CO/CO[sub 2] ratio produced. If gas diffusion through the boundary layer is fast, increased direct production of CO[sub 2] produces a higher temperature and a higher burning rate. If the supply of oxygen to the surface is limited by diffusion through the boundary layer, production of CO[sub 2] consumes half as much carbon as production of CO so carbon consumption rate is reduced even though temperature may be somewhat higher. Models of these complex interaction have been developed; however, the CO/CO[sub 2] ratio produced by the carbon-oxygen reaction must, at present be assumed or inferred from measurement of particle temperature. CO/CO[sub 2] rates can be strongly influenced by catalytic material in the carbon and by the char temperature. In this program we are measuring the CO/CO[sub 2] ratio for both catalyzed and uncatalyzed chars over a wide range of temperature. These results will then be used to develop predictive models for char temperature and burning rates.

  14. Radiocarbon dating of charred human bone remains preserved in urns excavated from medieval Buddhist cemetery in Japan

    Energy Technology Data Exchange (ETDEWEB)

    Nakamura, Toshio, E-mail: nakamura@nendai.nagoya-u.ac.j [Center for Chronological Research, Nagoya University, Chikusa, Nagoya 464-8602 (Japan); Sagawa, Shinichi; Yamada, Tetsuya [Gangoji Institute for Research of Cultural Properties, Nakain, Nara 630-8392 (Japan); Kanehara, Masaaki [School of Science Education, Nara University of Education, Takabatake, Nara 630-8528 (Japan); Tsuchimoto, Norio [Ichinomiya City Museum, Yamato, Ichinomiya 491-0922 (Japan); Minami, Masayo [Center for Chronological Research, Nagoya University, Chikusa, Nagoya 464-8602 (Japan); Omori, Takayuki [Graduate School of Environmental Studies, Nagoya University, Chikusa, Nagoya 464-8602 (Japan); Okuno, Mitsuru [Faculty of Science, Fukuoka University, Jonan, Fukuoka 814-0180 (Japan); Ohta, Tomoko [Center for Chronological Research, Nagoya University, Chikusa, Nagoya 464-8602 (Japan)

    2010-04-15

    For a preliminary test of {sup 14}C dating of cremated human remains, we have collected charred bone and wood-charcoal fragments from cremated remains contained in cinerary urns that had been excavated from medieval Buddhist cemetery at the Hoenji temple in Aichi prefecture, central Japan. More than 230 urn vessels were discovered from the excavated area of ca. 14 m wide and 14 m long. The identification of charred bone or charcoal fragments among the remains was performed by observation of surface appearance, inspection of fine structures by a microscope, bubble formation during the HCl treatments in preparing target material for AMS {sup 14}C dating, carbon and nitrogen contents, delta{sup 13}C and delta{sup 15}N values of the fragments. All {sup 14}C ages obtained for the samples that were identified as charred bone remains were almost consistent with the archeological age estimated based on typological analysis of respective urns. On the other hand, some {sup 14}C ages for the remains identified as wood charcoal, which had been produced from firewood or a wooden coffin during the cremation, were not consistent with archeological estimation, shifting toward older {sup 14}C ages, most probably as the result of old wood effect.

  15. Radiocarbon dating of charred human bone remains preserved in urns excavated from medieval Buddhist cemetery in Japan

    International Nuclear Information System (INIS)

    For a preliminary test of 14C dating of cremated human remains, we have collected charred bone and wood-charcoal fragments from cremated remains contained in cinerary urns that had been excavated from medieval Buddhist cemetery at the Hoenji temple in Aichi prefecture, central Japan. More than 230 urn vessels were discovered from the excavated area of ca. 14 m wide and 14 m long. The identification of charred bone or charcoal fragments among the remains was performed by observation of surface appearance, inspection of fine structures by a microscope, bubble formation during the HCl treatments in preparing target material for AMS 14C dating, carbon and nitrogen contents, δ13C and δ15N values of the fragments. All 14C ages obtained for the samples that were identified as charred bone remains were almost consistent with the archeological age estimated based on typological analysis of respective urns. On the other hand, some 14C ages for the remains identified as wood charcoal, which had been produced from firewood or a wooden coffin during the cremation, were not consistent with archeological estimation, shifting toward older 14C ages, most probably as the result of old wood effect.

  16. Adsorption of heavy metal ions from aqueous solutions by bio-char, a by-product of pyrolysis

    Science.gov (United States)

    Kılıç, Murat; Kırbıyık, Çisem; Çepelioğullar, Özge; Pütün, Ayşe E.

    2013-10-01

    Bio-char, a by-product of almond shell pyrolysis, was used as an alternative adsorbent precursor for the removal of heavy metal ions from aqueous solutions. The adsorption potential of almond shell bio-char for Ni(II) and Co(II) removal was investigated. Adsorption experiments were carried out by varying pH, adsorbent dosage, initial metal ion concentrations, contact time and temperature to determine the optimum conditions. To describe the equilibrium isotherms the experimental data were analyzed by the Langmuir, Freundlich, Dubinin-Radushkevich (D-R) and Temkin isotherm models. Pseudo-first order, pseudo-second order, and intraparticle diffusion kinetic models were used to find out the kinetic parameters and mechanism of adsorption process. The thermodynamic parameters such as ΔG°, ΔH° and ΔS° were calculated for predicting the nature of adsorption. The results showed that bio-char derived from pyrolysis of biomass can be used as a low-cost and effective adsorbent for removal of heavy metal ions from aqueous solutions.

  17. Sustainable development of tyre char-based activated carbons with different textural properties for value-added applications.

    Science.gov (United States)

    Hadi, Pejman; Yeung, Kit Ying; Guo, Jiaxin; Wang, Huaimin; McKay, Gordon

    2016-04-01

    This paper aims at the sustainable development of activated carbons for value-added applications from the waste tyre pyrolysis product, tyre char, in order to make pyrolysis economically favorable. Two activation process parameters, activation temperature (900, 925, 950 and 975 °C) and residence time (2, 4 and 6 h) with steam as the activating agent have been investigated. The textural properties of the produced tyre char activated carbons have been characterized by nitrogen adsorption-desorption experiments at -196 °C. The activation process has resulted in the production of mesoporous activated carbons confirmed by the existence of hysteresis loops in the N2 adsorption-desorption curves and the pore size distribution curves obtained from BJH method. The BET surface area, total pore volume and mesopore volume of the activated carbons from tyre char have been improved to 732 m(2)/g, 0.91 cm(3)/g and 0.89 cm(3)/g, respectively. It has been observed that the BET surface area, mesopore volume and total pore volume increased linearly with burnoff during activation in the range of experimental parameters studied. Thus, yield-normalized surface area, defined as the surface area of the activated carbon per gram of the precursor, has been introduced to optimize the activation conditions. Accordingly, the optimized activation conditions have been demonstrated as an activation temperature of 975 °C and an activation time of 4 h. PMID:26775155

  18. Adsorption of heavy metal ions from aqueous solutions by bio-char, a by-product of pyrolysis

    Energy Technology Data Exchange (ETDEWEB)

    Kılıç, Murat [Department of Chemical Engineering, Faculty of Engineering, Anadolu University, 26555 Eskişehir (Turkey); Kırbıyık, Çisem [Department of Chemical Engineering, Faculty of Engineering, Selçuk University, 42075 Konya (Turkey); Çepelioğullar, Özge [Department of Chemical Engineering, Faculty of Chemical and Metallurgical Engineering, Istanbul Technical University, 34469 Istanbul (Turkey); Pütün, Ayşe E., E-mail: aeputun@anadolu.edu.tr [Department of Chemical Engineering, Faculty of Engineering, Anadolu University, 26555 Eskişehir (Turkey)

    2013-10-15

    Bio-char, a by-product of almond shell pyrolysis, was used as an alternative adsorbent precursor for the removal of heavy metal ions from aqueous solutions. The adsorption potential of almond shell bio-char for Ni(II) and Co(II) removal was investigated. Adsorption experiments were carried out by varying pH, adsorbent dosage, initial metal ion concentrations, contact time and temperature to determine the optimum conditions. To describe the equilibrium isotherms the experimental data were analyzed by the Langmuir, Freundlich, Dubinin–Radushkevich (D–R) and Temkin isotherm models. Pseudo-first order, pseudo-second order, and intraparticle diffusion kinetic models were used to find out the kinetic parameters and mechanism of adsorption process. The thermodynamic parameters such as ΔG°, ΔH° and ΔS° were calculated for predicting the nature of adsorption. The results showed that bio-char derived from pyrolysis of biomass can be used as a low-cost and effective adsorbent for removal of heavy metal ions from aqueous solutions.

  19. Adsorption of heavy metal ions from aqueous solutions by bio-char, a by-product of pyrolysis

    International Nuclear Information System (INIS)

    Bio-char, a by-product of almond shell pyrolysis, was used as an alternative adsorbent precursor for the removal of heavy metal ions from aqueous solutions. The adsorption potential of almond shell bio-char for Ni(II) and Co(II) removal was investigated. Adsorption experiments were carried out by varying pH, adsorbent dosage, initial metal ion concentrations, contact time and temperature to determine the optimum conditions. To describe the equilibrium isotherms the experimental data were analyzed by the Langmuir, Freundlich, Dubinin–Radushkevich (D–R) and Temkin isotherm models. Pseudo-first order, pseudo-second order, and intraparticle diffusion kinetic models were used to find out the kinetic parameters and mechanism of adsorption process. The thermodynamic parameters such as ΔG°, ΔH° and ΔS° were calculated for predicting the nature of adsorption. The results showed that bio-char derived from pyrolysis of biomass can be used as a low-cost and effective adsorbent for removal of heavy metal ions from aqueous solutions.

  20. Supercritical water gasification of Eucalyptus grandis and related pyrolysis char: Effect of feedstock composition.

    Science.gov (United States)

    Louw, Jeanne; Schwarz, Cara E; Burger, Andries J

    2016-09-01

    Eucalyptus grandis (E. grandis) wood and char products derived from pyrolysis of E. grandis wood, were gasified in supercritical water at 450°C - with and without the use of a homogeneous (K2CO3) and heterogeneous (Ni/Al2O3-SiO2) catalyst. Gas yields and gasification efficiencies were measured experimentally and compared to calculated thermodynamic equilibrium values, specifically considering the effects of the O/C ratio and volatile matter content of the feed material. Thermodynamically, feed material with lower O/C ratios (0.22) typically resulted in higher CH4 yields (30mol/kgfeed,dry) and gasification efficiencies (188%). However, experimentally, feed material with lower O/C ratios and lower volatile matter resulted in the lowest CH4 yields and gasification efficiencies. Furthermore, a linear relationship between the carbon efficiency (CE) and both the volatile matter content and O/C ratio of the feed material was found to hold true in both catalytic and non-catalytic experiments. PMID:27343456

  1. Peroxide-assisted microwave activation of pyrolysis char for adsorption of dyes from wastewater.

    Science.gov (United States)

    Nair, Vaishakh; Vinu, R

    2016-09-01

    In this study, mesoporous activated biochar with high surface area and controlled pore size was prepared from char obtained as a by-product of pyrolysis of Prosopis juliflora biomass. The activation was carried out by a simple process that involved H2O2 treatment followed by microwave pyrolysis. H2O2 impregnation time and microwave power were optimized to obtain biochar with high specific surface area and high adsorption capacity for commercial dyes such as Remazol Brilliant Blue and Methylene Blue. Adsorption parameters such as initial pH of the dye solution and adsorbent dosage were also optimized. Pore size distribution, surface morphology and elemental composition of activated biochar were thoroughly characterized. H2O2 impregnation time of 24h and microwave power of 600W produced nanostructured biochar with narrow and deep pores of 357m(2)g(-1) specific surface area. Langmuir and Langmuir-Freundlich isotherms described the adsorption equilibrium, while pseudo second order model described the kinetics of adsorption. PMID:27268436

  2. Effect of sewage sledge and their bio-char on some soil qualities

    Science.gov (United States)

    Fathi, Hamed; Movahedi Naeini, Seyed Alireza; Mirzanejad, Mojan

    2015-04-01

    Bio char (BC) application as a soil amendment has achieved much interest and has been found that considerably improves soil nutrient status and crop yields on poor soils. However, information on the effect of BC on illitic soils in temperate climates is still insufficient. The primary objective in this study was to assess the influence of biochar on the soil physical properties, nutrient status and plant production. The result may also provide a reference for the use of biochars as a solution in agricultural waste management when sludge with considerable load of pathogens are involved. Soybean was already grown one year and will be repeated one more year with same treatments. The investigated soil properties included soil water content and mechanical resistance, pH, electrical conductivity (EC), calcium- acetate-lactate (CAL)-extractable P (PCAL) and K (KCAL), C, N, and nitrogen-supplying potential (NSP). The results show soil water content, potassium uptake and plant yield were increased. Heating sludge removed all pathogens and soybean yield was increased by 6%.

  3. Influence of the Pyrolysis Temperature on Sewage Sludge Product Distribution, Bio-Oil, and Char Properties

    DEFF Research Database (Denmark)

    Trinh, Ngoc Trung; Jensen, Peter Arendt; Dam-Johansen, Kim;

    2013-01-01

    behaviors of sludge oils were found to be considerably influenced by the applied pyrolysis temperatures. The sludge oil properties obtained at the optimal temperature of 575 °C were a HHV of 25.5 MJ/kg, a water-insoluble fraction of 18.7 wt %, a viscosity of 43.6 mPa s at 40 °C, a mean molecular weight of...... centrifugel reactor (PCR) at 475, 525, 575, and 625 °C. Maxima of both organic oil yield of 41 wt % on a dry ash free feedstock basis (daf) and a sludge oil energy recovery of 50% were obtained at 575 °C. The water-insoluble fraction, molecular-weight distribution, higher heating value (HHV), and thermal...... 392 g/mol, and metal concentrations lower than 0.14 wt % on a dry basis (db). Less optimal oil properties with respect to industrial applications were observed for oil samples obtained at 475 and 625 °C. Char properties of the 575 °C sample were an ash content of 81 wt % and a HHV of 6.1 MJ/kg db. A...

  4. Chemical and Isotopic Thresholds in Charring: Implications for the Interpretation of Charcoal Mass and Isotopic Data.

    Science.gov (United States)

    Pyle, Lacey A; Hockaday, William C; Boutton, Thomas; Zygourakis, Kyriacos; Kinney, Timothy J; Masiello, Caroline A

    2015-12-15

    Charcoal plays a significant role in the long-term carbon cycle, and its use as a soil amendment is promoted as a C sequestration strategy (biochar). One challenge in this research area is understanding the heterogeneity of charcoal properties. Although the maximum reaction temperature is often used as a gauge of pyrolysis conditions, pyrolysis duration also changes charcoal physicochemical qualities. Here, we introduce a formal definition of charring intensity (CI) to more accurately characterize pyrolysis, and we document variation in charcoal chemical properties with variation in CI. We find two types of responses to CI: either linear or threshold relationships. Mass yield decreases linearly with CI, while a threshold exists across which % C, % N, and δ(15)N exhibit large changes. This CI threshold co-occurs with an increase in charcoal aromaticity. C isotopes do not change from original biomass values, supporting the use of charcoal δ(13)C signatures to infer paleoecological conditions. Fractionation of N isotopes indicates that fire may be enriching soils in (15)N through pyrolytic N isotope fractionation. This influx of "black N" could have a significant impact on soil N isotopes, which we show theoretically using a simple mass-balance model. PMID:26523420

  5. Tetracycline adsorption onto activated carbons produced by KOH activation of tyre pyrolysis char.

    Science.gov (United States)

    Acosta, R; Fierro, V; Martinez de Yuso, A; Nabarlatz, D; Celzard, A

    2016-04-01

    Tyre pyrolysis char (TPC), produced when manufacturing pyrolysis oil from waste tyre, was used as raw material to prepare activated carbons (ACs) by KOH activation. KOH to TPC weight ratios (W) between 0.5 and 6, and activation temperatures from 600 to 800 °C, were used. An increase in W resulted in a more efficient development of surface area, microporosity and mesoporosity. Thus, ACs derived from TPC (TPC-ACs) with specific surface areas up to 814 m(2) g(-1) were obtained. TPC, TPC-ACs and a commercial AC (CAC) were tested for removing Tetracycline (TC) in aqueous phase, and systematic adsorption studies, including equilibrium, kinetics and thermodynamic aspects, were performed. Kinetics was well described by the pseudo-first order model for TPC, and by a pseudo second-order kinetic model for ACs. TC adsorption equilibrium data were also fitted by different isotherm models: Langmuir, Freundlich, Sips, Dubinin-Radushkevich, Dubinin-Astokov, Temkin, Redlich-Peterson, Radke-Prausnitz and Toth. The thermodynamic study confirmed that TC adsorption onto TPC-ACs is a spontaneous process. TC adsorption data obtained in the present study were compared with those reported in the literature, and differences were explained in terms of textural properties and surface functionalities. TPC-ACs had similar performances to those of commercial ACs, and might significantly improve the economic balance of the production of pyrolysis oil from waste tyres. PMID:26855221

  6. Computational Modelling of the Structural Integrity following Mass-Loss in Polymeric Charred Cellular Solids

    Directory of Open Access Journals (Sweden)

    J. P. M. Whitty

    2014-01-01

    Full Text Available A novel computational technique is presented for embedding mass-loss due to burning into the ANSYS finite element modelling code. The approaches employ a range of computational modelling methods in order to provide more complete theoretical treatment of thermoelasticity absent from the literature for over six decades. Techniques are employed to evaluate structural integrity (namely, elastic moduli, Poisson’s ratios, and compressive brittle strength of honeycomb systems known to approximate three-dimensional cellular chars. That is, reducing the mass of diagonal ribs and both diagonal-plus-vertical ribs simultaneously show rapid decreases in the structural integrity of both conventional and reentrant (auxetic, i.e., possessing a negative Poisson’s ratio honeycombs. On the other hand, reducing only the vertical ribs shows initially modest reductions in such properties, followed by catastrophic failure of the material system. Calculations of thermal stress distributions indicate that in all cases the total stress is reduced in reentrant (auxetic cellular solids. This indicates that conventional cellular solids are expected to fail before their auxetic counterparts. Furthermore, both analytical and FE modelling predictions of the brittle crush strength of both auxteic and conventional cellular solids show a relationship with structural stiffness.

  7. Synthesis and structural features of resorcinol-formaldehyde resin chars containing nickel nanoparticles

    Science.gov (United States)

    Galaburda, M. V.; Bogatyrov, V. M.; Skubiszewska-Zięba, J.; Oranska, O. I.; Sternik, D.; Gun'ko, V. M.

    2016-01-01

    A series of meso- and microporous carbons containing magnetic Ni nanoparticles (Ni/C) with a variety of Ni loadings were synthesized by a simple one-pot procedure through carbonization of resorcinol-formaldehyde polymers containing various amounts of nickel(II) acetate. Such composite materials were characterized by N2 sorption, Raman spectroscopy, X-ray diffraction (XRD), scanning electron microscopy (SEM) and Transmission electron microscope (TEM). The XRD patterns reveal peaks corresponding to face centered cubic nickel with the average size of crystallites of 17-18 nm. SEM and TEM results reveal that the formation of the nanoparticles took place mainly in the carbon spheres (1-2 μm in size) and on the outer surface as well. The as-prepared composites are characterized by a core-shell structure with well-crystallized graphitic shells about 8-15 nm in thickness. The Raman spectra show that Ni content influences the structure of the carbon. It was also shown that the morphology (particle shape and sizes) and porosity (pore volume and pore size distribution) of the chars are strongly dependent on water and nickel contents in the blends. One of the applications of Ni/C was demonstrated as a magnetically separable adsorbent.

  8. Properties of oil and char derived from slow pyrolysis of Tetraselmis chui.

    Science.gov (United States)

    Grierson, Scott; Strezov, Vladimir; Shah, Pushan

    2011-09-01

    Pyrolysis of biomass is a means to industrially manufacture renewable oil and gas, in addition to biochar for soil amendment and long-term carbon fixation. In this work, oil and char derived from the slow pyrolysis of the unicellular marine diatom Tetraselmis chui are analysed using a variety of techniques. The pyrolytic oil fraction exhibits a wide variety of fatty acids, alkanes, alkenes, amides, aldehydes, terpenes, pyrrolidinines, phytol and phenols, with a high heating value (HHV) of 28 MJ/kg. The biochar produced has a HHV of 14.5 MJ/kg and reveals a number of properties that are potentially valuable from an agronomic point of view, including high cation exchange capacity (CEC), large concentration of N, and a low C:N ratio. The quantity of C in T. chui biochar that can be expected to stabilise in soil amounts to approximately 9%/wt of the original feedstock, leading to a potential net reduction in atmospheric CO(2). PMID:21704515

  9. Estimation of surface heat flux for ablation and charring of thermal protection material

    Science.gov (United States)

    Qian, Wei-qi; He, Kai-feng; Zhou, Yu

    2016-07-01

    Ablation of the thermal protection material of the reentry hypersonic flight vehicle is a complex physical and chemical process. To estimate the surface heat flux from internal temperature measurement is much more complex than the conventional inverse heat conduction problem case. In the paper, by utilizing a two-layer pyrogeneration-plane ablation model to model the ablation and charring of the material, modifying the finite control volume method to suit for the numerical simulation of the heat conduction equation with variable-geometry, the CGM along with the associated adjoint problem is developed to estimate the surface heat flux. This estimation method is verified with a numerical example at first, the results show that the estimation method is feasible and robust. The larger is the measurement noise, the greater is the deviation of the estimated result from the exact value, and the measurement noise of ablated surface position has a significant and more direct influence on the estimated result of surface heat flux. Furthermore, the estimation method is used to analyze the experimental data of ablation of blunt Carbon-phenolic material Narmco4028 in an arc-heater. It is shown that the estimated surface heat flux agrees with the heating power value of the arc-heater, and the estimation method is basically effective and potential to treat the engineering heat conduction problem with ablation.

  10. Frequency measurement of the g-factor of charred dextrose of DPPH

    International Nuclear Information System (INIS)

    Measuring the frequency ratio νsub(e)/νsub(p) it is possible to calculate the g-factor according to g=K. νsub(e)/νsub(p) where K is the conversionfactor (K=3,042064362.10-3). To determine the magnetic field or equivalent the frequency νsub(p) at the locus of the ESR sample, this sample is placed in the center of a NMR-probe containing glycerol doped with 0,2 M CuSO4. Both signals are measured and stored simultaneously. The frequency ratio νsub(e)/νsub(p) is measured at the simultaneous zero passage of both signals. The obtained value are corrected due to the chemical shift of the NMR-probe compared with the resonance frequency of free protons and yields for the g-factor of charred dextrose g=2,0026208+-0,4 ppm and of DPPH g=2,0035036+-0,4 ppm

  11. Adsorption of SO2 on bituminous coal char and activated carbon fiber

    Science.gov (United States)

    DeBarr, J.A.; Lizzio, A.A.; Daley, M.A.

    1997-01-01

    The SO2 adsorption behaviors of activated carbons produced from Illinois coal and of commercially prepared activated carbon fibers (ACFs) were compared. There was no relation between surface area of coal-based carbons and SO2 adsorption, whereas adsorption of SO2 on the series of ACFs was inversely proportional to N2 BET surface area. Higher surface area ACFs had wider pores and adsorbed less SO2; thus, pore size distribution is thought to play a significant role in SO2 adsorption for these materials. Oxidation with HNO3 and/or H2SO4, followed by heat treatment at 700-925 ??C to remove carbon-oxygen complexes, resulted in increased SO2 adsorption for both coal chars and ACFs. This behavior was explained by an increase in the available number of free sites, previously occupied by oxygen and now available for SO2 adsorption. The use of nitrogen-containing functional groups on ACFs of proper pore size shows promise for further increasing SO2 adsorption capacities. Knowledge of the relationship among the number of free sites, pore size, and surface chemistry on corresponding SO2 adsorption should lead to the development of more efficient adsorbents prepared from either coal or ACFs.

  12. Different characteristics of char and soot in the atmosphere and their ratio as an indicator for source identification in Xi'an, China

    Directory of Open Access Journals (Sweden)

    Y. M. Han

    2010-01-01

    Full Text Available Numerous definitions and analytical techniques for elemental (or black carbon (EC have been published in the scientific literature, but still no generally accepted interdisciplinary definition exists. EC is not a single chemical compound, but is mainly composed of two parts of carbon contents: combustion residues from pyrolysis and combustion emissions formed via gas-to-particle conversion. Accordingly EC is subdivided into two classes: char and soot. Char is defined as carbonaceous materials obtained by heating organic substances and formed directly from pyrolysis, or as an impure form of graphitic carbon obtained as a residue when carbonaceous material is partially burned or heated with limited access of air. Soot is defined as only those carbon particles that form at high temperature via gas-phase processes. Since the different classes of EC have different chemical and physical properties, their optical light-absorbing properties differ, so that it is essential to differentiate them in the environment. The thermal optical reflectance (TOR method was used to differentiate between char-EC and soot-EC according to its stepwise thermal evolutional oxidation of different carbon fractions under different temperatures and atmosphere. Char-EC and soot-EC are operationally defined as EC1-OP and EC2+EC3 (EC1, EC2 and EC3 corresponding to carbon fractions evolved at 550, 700 and 800 °C in a 98% He/2% O2 atmosphere, respectively, respectively. One year of observations of the daily and seasonal variations of carbonaceous particles were conducted in Xi'an, China in 2004 to demonstrate the different characteristics of char and soot in the atmosphere. Total carbon (TC, organic carbon (OC, EC and char-EC showed similar seasonal trends, with high concentrations in winter and low concentrations in summer, while soot-EC revealed relatively small seasonal variations, with maximum concentration (1.85±0.72 μg m−3 in spring and minimum

  13. Steam gasification of char from wood chips fast pyrolysis: Development of a semi-empirical model for a fluidized bed reactor application

    International Nuclear Information System (INIS)

    This study, performed in the context of GAYA project, focuses on the development of a simple predictive model about steam gasification of char from woodchips fast pyrolysis. A semi-empirical model was developed through experiments in a macro thermogravimetric analyzer which owns the peculiar ability of fast heating, as well as to deal with macro-size particles and higher mass loads compared to conventional TGA. The experimental results show that gasification is controlled by chemical kinetics and internal transfer phenomena. During gasification, char particles can be considered as isothermal in a given range of temperatures and particle sizes, more likely for low values. The gasification model was based on the effectiveness factor, which involves the chemical kinetics and diffusion rate. The chemical kinetics were expressed by a classical Arrhenius law, whereas empirical expressions from mathematical fitting of the experimental data were established for the diffusion coefficient and surface function. The diffusion coefficient from this work is suspected to probably include supplementary rate limiting phenomena, apart from steam porous diffusion, such as H2 inhibition and/or the decrease of temperature within char particles because of the endothermic character of gasification. The model globally predicts with accuracy the gasification rate in typical operating conditions of a fluidized bed reactor. For its simplicity and reliability, this approach can be used for the modelling of char gasification in the conditions of interest. - Highlights: • Char gasification is controlled by chemical kinetics and internal transfers. • Char particles are isothermal during gasification only at certain conditions. • The temperature decrease within char particles may affect gasification rate. • Gasification within the particle could be inhibited by the produced H2. • The developed semi-empirical model predicts with accuracy gasification rate

  14. Bone char: a clean and renewable phosphorus fertilizer with cadmium immobilization capability.

    Science.gov (United States)

    Siebers, Nina; Leinweber, Peter

    2013-01-01

    Soil contamination with Cd from P fertilizer and other anthropogenic and geogenic sources is a serious problem. In situ immobilization by P application to soil is known as an applicable remediation technique leading to reduced Cd uptake by plants, and use of a Cd-free P fertilizer from renewable sources would be most favorable. Bone char (BC) (15% P, 28% Ca, 0.7% Mg) may be used as such a quality P fertilizer, but it is unknown if its dissolution in soil provides sufficient P and immobilizes Cd in moderately contaminated soils. We incubated BC and triple superphosphate (TSP) in 11 soils that contained between 0.3 to 19.6 mg Cd kg and determined the kinetics of P dissolution during a time period of 145 d. The concomitant Cd immobilization was determined by extracting the mobile Cd with 1 mol L NHNO solution. For most soils, BC increased the concentration of labile P immediately after application, reaching a maximum after 34 d, although the solubility was below that of TSP (2.9-19.3 vs. 4.1-24.0%). Among five kinetic models, the Langmuir-type equation provided the best description of P dissolution from BC and TSP. The Cd immobilization resulting from BC dissolution exceeded that of TSP by a factor of 1.4 to 2.7. The P dissolution from BC was negatively correlated with pH and positively with P sorption capacity, whereas Cd immobilization was positively correlated with soil pH. These causal relationships were expressed in multiple equations that enable predictions of P dissolution and Cd immobilization and thus may help to introduce BC as sustainable P fertilizer and useful soil amendment. PMID:23673832

  15. Performance prediction and validation of equilibrium modeling for gasification of cashew nut shell char

    Directory of Open Access Journals (Sweden)

    M. Venkata Ramanan

    2008-09-01

    Full Text Available Cashew nut shell, a waste product obtained during deshelling of cashew kernels, had in the past been deemed unfit as a fuel for gasification owing to its high occluded oil content. The oil, a source of natural phenol, oozes upon gasification, thereby clogging the gasifier throat, downstream equipment and associated utilities with oil, resulting in ineffective gasification and premature failure of utilities due to its corrosive characteristics. To overcome this drawback, the cashew shells were de-oiled by charring in closed chambers and were subsequently gasified in an autothermal downdraft gasifier. Equilibrium modeling was carried out to predict the producer gas composition under varying performance influencing parameters, viz., equivalence ratio (ER, reaction temperature (RT and moisture content (MC. The results were compared with the experimental output and are presented in this paper. The model is quite satisfactory with the experimental outcome at the ER applicable to gasification systems, i.e., 0.15 to 0.30. The results show that the mole fraction of (i H2, CO and CH4 decreases while (N2 + H2O and CO2 increases with ER, (ii H2 and CO increases while CH4, (N2 + H2O and CO2 decreases with reaction temperature, (iii H2, CH4, CO2 and (N2 + H2O increases while CO decreases with moisture content. However at an equivalence ratio less than 0.15, the model predicts an unrealistic composition and is observed to be non valid below this ER.

  16. Slash-and-char: An ancient agricultural technique holds new promise for management of soils contaminated by Cd, Pb and Zn

    International Nuclear Information System (INIS)

    Heavy metal contamination of agricultural soils is of worldwide concern. Unfortunately, there are currently no efficient and sustainable approaches for addressing this concern. In this study, we conducted a field experiment in which an agricultural soil highly contaminated by cadmium (Cd), lead (Pb) and zinc (Zn) was treated on-site by an ancient agricultural technique, ‘slash-and-char’, that was able to convert the biomass feedstock (rice straw) into biochar in only one day. We found evidence that in comparison to the untreated soil, the treated soil was associated with decreased bioavailability of the heavy metals and increased vegetable yields. Most importantly, the treatment was also coupled with dramatic reductions in concentrations of the heavy metals in vegetables, which made it possible to produce safe crops in this highly contaminated soil. Collectively, our results support the idea that slash-and-char offers new promise for management of soils contaminated by Cd, Pb and Zn. - Highlights: • We explored the potential of slash-and-char in dealing with soil metal pollution. • Metal bioavailability in the soil treated with slash-and-char was reduced by 24–65%. • Vegetable yield in the soil treated with slash-and-char was increased by 34–67%. • Slash-and-char could reduce the metal concentration in vegetables to a safe level. - An ancient agricultural technique called ‘slash-and-char’ offers new promise for management of soils contaminated multiply by Cd, Pb and Zn

  17. Pyrolysis of waste animal fats in a fixed-bed reactor: Production and characterization of bio-oil and bio-char

    Energy Technology Data Exchange (ETDEWEB)

    Ben Hassen-Trabelsi, A., E-mail: aidabenhassen@yahoo.fr [Centre de Recherche et de Technologies de l’Energie (CRTEn), Technopôle Borj-Cédria, B.P 95, 2050, Hammam Lif (Tunisia); Kraiem, T. [Centre de Recherche et de Technologies de l’Energie (CRTEn), Technopôle Borj-Cédria, B.P 95, 2050, Hammam Lif (Tunisia); Département de Géologie, Université de Tunis, 2092, Tunis (Tunisia); Naoui, S. [Centre de Recherche et de Technologies de l’Energie (CRTEn), Technopôle Borj-Cédria, B.P 95, 2050, Hammam Lif (Tunisia); Belayouni, H. [Département de Géologie, Université de Tunis, 2092, Tunis (Tunisia)

    2014-01-15

    Highlights: • Produced bio-fuels (bio-oil and bio-char) from some animal fatty wastes. • Investigated the effects of main parameters on pyrolysis products distribution. • Determined the suitable conditions for the production of the maximum of bio-oil. • Characterized bio-oils and bio-chars obtained from several animal fatty wastes. - Abstract: Several animal (lamb, poultry and swine) fatty wastes were pyrolyzed under nitrogen, in a laboratory scale fixed-bed reactor and the main products (liquid bio-oil, solid bio-char and syngas) were obtained. The purpose of this study is to produce and characterize bio-oil and bio-char obtained from pyrolysis of animal fatty wastes. The maximum production of bio-oil was achieved at a pyrolysis temperature of 500 °C and a heating rate of 5 °C/min. The chemical (GC–MS analyses) and spectroscopic analyses (FTIR analyses) of bio-oil showed that it is a complex mixture consisting of different classes of organic compounds, i.e., hydrocarbons (alkanes, alkenes, cyclic compounds…etc.), carboxylic acids, aldehydes, ketones, esters,…etc. According to fuel properties, produced bio-oils showed good properties, suitable for its use as an engine fuel or as a potential source for synthetic fuels and chemical feedstock. Obtained bio-chars had low carbon content and high ash content which make them unattractive for as renewable source energy.

  18. The influence of included minerals on the intrinsic reactivity of chars prepared under N{sub 2} and CO{sub 2} environment

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Hong; Li, Huan; Chen, Jiabao; Zhao, Bo; Hu, Guangzhou [China Univ. of Mining and Technology, Jiangsu (China). School of Chemical Engineering

    2013-07-01

    Oxy-fuel technology could be successfully used to retrofit existing coal-fired power plants or alternatively be used to design and build new coal-fired power plants with almost zero emissions. Char reactivity under oxy-fuel conditions will have a significant impact on the coal burnout. In this paper, two fractions, representing organic-rich particles and organic particles with included minerals, were separated from each of three Chinese coals of different rank. They were then devolatilized at 1,450 C in a drop tube furnace (DTF) under N{sub 2} and CO{sub 2} environment, respectively. The chars were subjected to nitrogen adsorption study, thermogravimetric analysis and XRD analysis. It was found that char reactivity of all three pairs of chars were increased under CO{sub 2} environment as compared with that under N{sub 2} environment, but with differing trend. For the organic-rich samples the reactivity difference is increased with decreasing rank. On the contrary, for the samples of organic particles with included minerals, the reactivity difference is decreased with decreasing rank. Mechanism analysis showed that they are resulted not from gasification, but from a combination of changes in surface area and in the orderness of carbon structure in the chars, both of which, in turn, are resulted from the higher heat capacity of CO{sub 2} and the interaction between metastable liquid phase and the included minerals.

  19. Pyrolysis of waste animal fats in a fixed-bed reactor: Production and characterization of bio-oil and bio-char

    International Nuclear Information System (INIS)

    Highlights: • Produced bio-fuels (bio-oil and bio-char) from some animal fatty wastes. • Investigated the effects of main parameters on pyrolysis products distribution. • Determined the suitable conditions for the production of the maximum of bio-oil. • Characterized bio-oils and bio-chars obtained from several animal fatty wastes. - Abstract: Several animal (lamb, poultry and swine) fatty wastes were pyrolyzed under nitrogen, in a laboratory scale fixed-bed reactor and the main products (liquid bio-oil, solid bio-char and syngas) were obtained. The purpose of this study is to produce and characterize bio-oil and bio-char obtained from pyrolysis of animal fatty wastes. The maximum production of bio-oil was achieved at a pyrolysis temperature of 500 °C and a heating rate of 5 °C/min. The chemical (GC–MS analyses) and spectroscopic analyses (FTIR analyses) of bio-oil showed that it is a complex mixture consisting of different classes of organic compounds, i.e., hydrocarbons (alkanes, alkenes, cyclic compounds…etc.), carboxylic acids, aldehydes, ketones, esters,…etc. According to fuel properties, produced bio-oils showed good properties, suitable for its use as an engine fuel or as a potential source for synthetic fuels and chemical feedstock. Obtained bio-chars had low carbon content and high ash content which make them unattractive for as renewable source energy

  20. Adding the combination of CNTs and MoS2 into halogen-free flame retarding TPEE with enhanced the anti-dripping behavior and char forming properties

    International Nuclear Information System (INIS)

    Highlights: • Introduction the combination of the CNTs and MoS2 into P–N flame retarding TPEE. • Binary synergists for P–N flame retardants in TPEE. • Increase of char yield and form the stable carbonaceous char. - Abstract: In this paper, the nanocomposites thermoplastic polyester-ether elastomer (TPEE) with phosphorus–nitrogen (P–N) flame retardants, carbon nanotubes (CNTs) and molybdenum disulfide (MoS2) was prepared by melt blending. TPEE containing P–N flame retardant, CNTs and MoS2 achieved UL94 V-0 rating due to the better barrier effect of the special structure. The structure was supported by the result of rheological properties. The thermal stability was studied by thermal gravimetric analysis (TGA) and char residue characterization was investigated by SEM–EDX measurements. The results demonstrated that the combination of CNTs and MoS2 results in the increase of char yield and the formation of the thermally stable char which can effectively prevent in the dripping behavior during the burning process

  1. Structural features of resorcinol–formaldehyde resin chars and interfacial behavior of water co-adsorbed with low-molecular weight organics

    Energy Technology Data Exchange (ETDEWEB)

    Gun’ko, Vladimir M., E-mail: vlad_gunko@ukr.net [Chuiko Institute of Surface Chemistry, 17 General Naumov Street, 03164 Kyiv (Ukraine); Bogatyrov, Viktor M.; Turov, Vladimir V. [Chuiko Institute of Surface Chemistry, 17 General Naumov Street, 03164 Kyiv (Ukraine); Leboda, Roman; Skubiszewska-Zięba, Jadwiga [Faculty of Chemistry, Maria Curie-Skłodowska University, 20031 Lublin (Poland); Urubkov, Iliya V. [Kurdyumov Institute of Metal Physics, 36 Vernadsky Boulevard, 03142 Kyiv (Ukraine)

    2013-10-15

    Products of resorcinol–formaldehyde resin carbonization (chars) are characterized by different morphology (particle shape and sizes) and texture (specific surface area, pore volume and pore size distribution) depending on water content during resin polymerization. At a low amount of water (C{sub w} = 37.8 wt.%) during synthesis resulting in strongly cross-linked polymers, carbonization gives nonporous particles. An increase in the water content to 62.7 wt.% results in a nano/mesoporous char, but if C{sub w} = 73.3 wt.%, a char is purely nanoporous. Despite these textural differences, the Raman spectra of all the chars are similar because of the similarity in the structure of their carbon sheets with a significant contribution of sp{sup 3} C atoms. However, the difference in the spatial organization of the carbon sheet stacks in the particles results in the significant differences in the textural and morphological characteristics and in the adsorption properties of chars with respect to water, methane, benzene, hydrogen, methylene chloride, and dimethylsulfoxide.

  2. Structural features of resorcinol-formaldehyde resin chars and interfacial behavior of water co-adsorbed with low-molecular weight organics

    Science.gov (United States)

    Gun'ko, Vladimir M.; Bogatyrov, Viktor M.; Turov, Vladimir V.; Leboda, Roman; Skubiszewska-Zięba, Jadwiga; Urubkov, Iliya V.

    2013-10-01

    Products of resorcinol-formaldehyde resin carbonization (chars) are characterized by different morphology (particle shape and sizes) and texture (specific surface area, pore volume and pore size distribution) depending on water content during resin polymerization. At a low amount of water (Cw = 37.8 wt.%) during synthesis resulting in strongly cross-linked polymers, carbonization gives nonporous particles. An increase in the water content to 62.7 wt.% results in a nano/mesoporous char, but if Cw = 73.3 wt.%, a char is purely nanoporous. Despite these textural differences, the Raman spectra of all the chars are similar because of the similarity in the structure of their carbon sheets with a significant contribution of sp3 C atoms. However, the difference in the spatial organization of the carbon sheet stacks in the particles results in the significant differences in the textural and morphological characteristics and in the adsorption properties of chars with respect to water, methane, benzene, hydrogen, methylene chloride, and dimethylsulfoxide.

  3. Intensification of adsorption process by using the pyrolytic char from waste tires to remove chromium(Ⅵ) from wastewater

    Institute of Scientific and Technical Information of China (English)

    ZHOU Jie; YANG Yong-rong

    2004-01-01

    Pyrolysis has the potential of transforming waste into valuable recyclable products. Pyrolytic char(PC) is one of the most important products from the pyrolysis of used tires. One of the most significant applications for pyrolytic char recovered is used for the removal of Cr(Ⅵ) in the wastewater effluent to control waste by waste. The surface chemistry properties of surface element distribution / concentration and chemical structure were examined for the pyrolytic char and the commercial activated carbon(CAC) respectively. The results showed that surfaces of PC possesses a large amount of ester and hydrocarbon graft, whereas there are mainly carbon functional components of C-OH, C=O and COOH on the surface of CAC. Therefore the surface electronegativity of PC is lower than that of CAC in the water. The repulsive interactions between the surfaces of PC and the negatively charged Cr(Ⅵ) ion are weaker than that of CAC, which results in an intensification of the adsorption process by the utilization of PC. The adsorption isotherms of Cr(Ⅵ) ion on the two kinds of carbons were determined experimentally. The larger adsorption amount on the PC in the case of Cr(Ⅵ) may be attributed mainly to its special surface micro-chemical environment. The mechanism of the removal Cr(Ⅵ) from aqueous solution was assumed to be the integration of adsorption and redox reaction. The adsorption was the rate-controlled step for Cr(Ⅵ) removal. The adsorption of Cr(Ⅵ) has been identified as pseudo-second- order kinetics. The rate constants of adsorption have been evaluated.

  4. SiteChar - methodology for a fit-for-purpose assessment of CO2 storage sites in Europe

    International Nuclear Information System (INIS)

    The FP7-funded SiteChar project examined the entire CO2 geological storage site characterisation process, from the initial feasibility studies through to the final stage of application for a CO2 storage permit based on criteria defined by the relevant European legislation. The SiteChar work-flow for CO2 geological storage site characterisation provides a description of all elements of a site characterisation study, as well as guidance to streamline the site characterisation process and make sure that the output covers the aspects mentioned in the European Community (EC) Storage Directive. Five potential European storage sites, representative of prospective geological contexts, were considered as test sites for the research work: a North Sea multi-store site (hydrocarbon field and aquifer) offshore Scotland; an onshore aquifer in Denmark; an onshore gas field in Poland; an aquifer offshore in Norway; and an aquifer in the Southern Adriatic Sea. This portfolio combines complementary sites that allowed to encompass the different steps of the characterisation work-flow. A key innovation was the development of internal 'dry-run' permit applications at the Danish and Scottish sites and their review by relevant regulatory authorities. This process helped to refine the site characterisation work-flow, and aimed to identify remaining gaps in site-specific characterisation, needed to secure storage permits under the EC Storage Directive as implemented in 'host' Member States. SiteChar considered the important aspect of the public awareness and public opinions of these new technologies, in parallel to technical issues, on the onshore Polish and offshore Scottish sites. A new format to assist public opinion-forming processes was tested involving a small sample of local communities. Generic as well as site-specific information was made available to the general and local public via the internet and at information meetings. These exercises provide insight in

  5. Conversion of nitrogen compounds and tars obtained from pre-composted pig manure pyrolysis, over nickel loaded brown coal char

    International Nuclear Information System (INIS)

    Fuel gas production and nitrogen transformation during pig manure pyrolysis from room temperature to 900 °C are investigated. The catalytic decomposition of the derived volatiles is also studied. Ammonia, HCN and N2 were obtained as the main N-containing gases. Ammonia was mainly emitted below 700 °C, which corresponds to 24.8 wt% of the nitrogen in the manure. Hydrogen cyanide and N2 gases obviously formed at temperatures above 700 °C, while the HCN concentration was as low as one ninth that of NH3 and one fifth of the concentration of nitrogen even at 900 °C. Thermal cracking of the pyrolysis volatiles produced little NH3, but noticeably increased HCN formation. When the prepared nickel-loaded brown coal char (LY-Ni) was added to the second part of the reactor (second stage) as a catalyst, most of the N-containing species in the volatiles converted into N2 gas. It suggests that LY-Ni has high catalytic activity for the conversion of N-containing compounds. Significant quantities of light fuel gases (H2, CO and CH4) were also generated. Compared with sand, 5.8 times (H2 and CO) the amount of gases was produced with the LY-Ni char at 650 °C. Decomposition of the manure volatiles depends on the catalyst temperature. Total product gases approximately doubled in yield when the catalyst temperature increased from 450 to 550 °C, and the volatiles conversion (based on carbon balance of the manure volatiles) increased from 72.4 wt% to 92.0 wt%. At 600–700 °C, the volatiles conversions stabilized at high levels of 96.7–98.2 wt%. -- Highlights: •The main N-containing gases from pig manure pyrolysis were NH3, HCN and N2. •Thermal cracking for the pig manure volatiles promoted HCN formation noticeably, and did little effect on NH3. •A nickel-loaded brown coal char converted the N in the pig manure volatiles mostly into N2 gas. •Light fuel gases, such as H2, CO and CH4, were significantly generated under the prepared nickel-loaded brown coal char

  6. SiteChar – Methodology for a Fit-for-Purpose Assessment of CO2 Storage Sites in Europe

    Directory of Open Access Journals (Sweden)

    Delprat-Jannaud F.

    2015-04-01

    Full Text Available The FP7-funded SiteChar project examined the entire CO2 geological storage site characterisation process, from the initial feasibility studies through to the final stage of application for a CO2 storage permit based on criteria defined by the relevant European legislation. The SiteChar workflow for CO2 geological storage site characterisation provides a description of all elements of a site characterisation study, as well as guidance to streamline the site characterisation process and make sure that the output covers the aspects mentioned in the European Community (EC Storage Directive. Five potential European storage sites, representative of prospective geological contexts, were considered as test sites for the research work: a North Sea multi-store site (hydrocarbon field and aquifer offshore Scotland; an onshore aquifer in Denmark; an onshore gas field in Poland; an aquifer offshore in Norway; and an aquifer in the Southern Adriatic Sea. This portfolio combines complementary sites that allowed to encompass the different steps of the characterisation workflow. A key innovation was the development of internal ‘dry-run’ permit applications at the Danish and Scottish sites and their review by relevant regulatory authorities. This process helped to refine the site characterisation workflow, and aimed to identify remaining gaps in site-specific characterisation, needed to secure storage permits under the EC Storage Directive as implemented in ‘host’ Member States. SiteChar considered the important aspect of the public awareness and public opinions of these new technologies, in parallel to technical issues, on the onshore Polish and offshore Scottish sites. A new format to assist public opinion-forming processes was tested involving a small sample of local communities. Generic as well as site-specific information was made available to the general and local public via the internet and at information meetings. These exercises provide insight

  7. Effect of coal rank and mineral matter on gasification reactivity of coal char treated at high temperature; Netsushorishita sekitan char no gas ka tokusei ni taisuru tanshu oyobi kobutsushitsu no eikyo

    Energy Technology Data Exchange (ETDEWEB)

    Morishita, K.; Takei, H.; Harano, A.; Takarada, T. [Gunma University, Gunma (Japan). Faculty of Engineering

    1996-10-28

    In the wide range from brown coal to anthracite, an investigation was made of effects of heat treatment on physical/chemical properties and of coal rank dependence. For the experiment, 12 kinds of coal samples were used, and for heat treatment, the fluidized bed heated by the electric furnace and the infrared-ray gold image furnace were used. To examine characteristics of the heat-treated coal char, conducted were oxygen gasification, TPD measurement, XRD measurement, alkali metal measurement, and pore distribution measurement. The following were obtained from the experiment. The gasification reaction rate of the char heat-treated in the temperature range between 900{degree}C to 1700{degree}C decreases with a rise of the temperature of heat treatment, and the degree of decrease in the rate depends on coal rank. The order of gasification rate between coal ranks depends on the temperature of heat treatment, and the lower the heat treatment temperature is, the more largely the gasification rate is influenced by catalysis of mineral matters included in the coal. As causes of the decrease in gasification rate associated with the rise in temperature of heat treatment, indicated were release of alkali metal having catalysis and decrease of active sites by carbonaceous crystallinity. 6 figs.

  8. Coal combustion science: Task 1, Coal char combustion: Task 2, Fate of mineral matter. Quarterly progress report, July--September 1993

    Energy Technology Data Exchange (ETDEWEB)

    Hardesty, D.R. [ed.; Hurt, R.H.; Davis, K.A.; Baxter, L.L.

    1994-07-01

    Progress reports are presented for the following tasks: (1) kinetics and mechanisms of pulverized coal char combustion and (2) fate of inorganic material during coal combustion. The objective of Task 1 is to characterize the combustion behavior of selected US coals under conditions relevant to industrial pulverized coal-fired furnaces. In Sandia`s Coal Combustion Laboratory (CCL), optical techniques are used to obtain high-resolution images of individual burning coal char particles and to measure, in situ, their temperatures, sizes, and velocities. Detailed models of combustion transport processes are then used to determine kinetic parameters describing the combustion behavior as a function of coal type and combustion environment. Partially reacted char particles are also sampled and characterized with advanced materials diagnostics to understand the critical physical and chemical transformations that influence reaction rates and burnout times. The ultimate goal of the task is the establishment of a data base of the high temperature reactivities of chars from strategic US coals, from which important trends may be identified and predictive capabilities developed. The overall objectives for task 2 are: (1) to complete experimental and theoretical investigation of ash release mechanisms; (2) to complete experimental work on char fragmentation; (3) to establish the extent of coal (as opposed to char) fragmentation as a function of coal type and particle size; (4) to develop diagnostic capabilities for in situ, real-time, qualitative indications of surface species composition during ash deposition, with work continuing into FY94; (5) to develop diagnostic capabilities for in situ, real-time qualitative detection of inorganic vapor concentrations; and (6) to conduct a literature survey on the current state of understanding of ash deposition, with work continuing into FY94.

  9. Measurements of Gasification Characteristics of Coal and Char in CO2-Rich Gas Flow by TG-DTA

    Directory of Open Access Journals (Sweden)

    Zhigang Li

    2013-01-01

    Full Text Available Pyrolysis, combustion, and gasification properties of pulverized coal and char in CO2-rich gas flow were investigated by using gravimetric-differential thermal analysis (TG-DTA with changing O2%, heating temperature gradient, and flow rate of CO2-rich gases provided. Together with TG-DTA, flue gas generated from the heated coal, such as CO, CO2, and hydrocarbons (HCs, was analyzed simultaneously on the heating process. The optimum O2% in CO2-rich gas for combustion and gasification of coal or char was discussed by analyzing flue gas with changing O2 from 0 to 5%. The experimental results indicate that O2% has an especially large effect on carbon oxidation at temperature less than 1100°C, and lower O2 concentration promotes gasification reaction by producing CO gas over 1100°C in temperature. The TG-DTA results with gas analyses have presented basic reference data that show the effects of O2 concentration and heating rate on coal physical and chemical behaviors for the expected technologies on coal gasification in CO2-rich gas and oxygen combustion and underground coal gasification.

  10. Effect of sewage sledge and their bio-char on some soil qualities in Second year cropping

    Science.gov (United States)

    fathi dokht, hamed; Movahedi Naeini, Seyed Alireza; Dordipor, Esmaeil; mirzanejad, moujan

    2016-04-01

    Bio char (BC) application as a soil amendment has achieved much interest and has been found that considerably improves soil nutrient status and crop yields on poor soils. However, information on the effect of BC on illitic soils in temperate climates is still insufficient. The primary objective in this study was to assess the influence of sewage sledge and their bio-char on the soil physical properties, nutrient status and plant production in Second year cropping. The result may also provide a reference for the use of biochars as a solution in agricultural waste management when sludge with considerable load of pathogens are involved. Soybean was already grown one year and will be repeated one more year with same treatments. The investigated soil properties included soil water content and mechanical resistance, pH, electrical conductivity (EC), calcium- acetate-lactate (CAL)-extractable P (PCAL) and K (KCAL), C, N, and nitrogen-supplying potential (NSP). The results show soil water content, potassium uptake and plant yield were increased. Heating sludge removed all pathogens and soybean yield was increased by 7%.

  11. Effects of Post-Pyrolysis Air Oxidation of Biomass Chars on Adsorption of Neutral and Ionizable Compounds.

    Science.gov (United States)

    Xiao, Feng; Pignatello, Joseph J

    2016-06-21

    This study was conducted to understand the effects of thermal air oxidation of biomass chars experienced during formation or production on their adsorptive properties toward various compounds, including five neutral nonpolar and polar compounds and seven weak acids and bases (pKa = 3-5.2) selected from among industrial chemicals and the triazine and phenoxyacetic acid herbicide classes. Post-pyrolysis air oxidation (PPAO) at 400 °C of anoxically prepared wood and pecan shell chars for up to 40 min enhanced the mass-normalized adsorption at pH ∼ 7.4 of all test compounds, especially the weak acids and bases, by up to 100-fold. Both general and specific effects were identified. The general effect results from "reaming" of pores by the oxidative removal of pore wall matter and/or tarry deposits generated during the pyrolysis step. Reaming creates new surface area and enlarges nanopores, which helps relieve steric hindrance to adsorption. The specific effect results from creation of new acidic functionality that provides sites for the formation of very strong, charge-assisted hydrogen bonds (CAHB) with solutes having comparable pKa. The CAHB hypothesis was supported by competition experiments and the finding that weak acid anion adsorption increased with surface carboxyl content, despite electrostatic repulsion from the growing negative charge. The results provide insight into the effects of air oxidation on pollutant retention. PMID:27152745

  12. Characterization of burning and CO2 gasification of chars from mixtures of Zonguldak (Turkey) and Australian bituminous coals

    International Nuclear Information System (INIS)

    In this study, different mixtures (30 wt.% + 70 wt.% and 50 wt.% + 50 wt.%, respectively) of Zonguldak bituminous coal (Turkey) and an Australian bituminous coal are carbonized to obtain char samples. The ignition temperatures of the samples are determined by sending O2 onto the samples in a system designed for determining the ignition temperature. The gasification reactivity of the chars in a CO2 atmosphere is also measured at temperatures between 800 deg. C and 1050 deg. C. The relationship between the ignition temperature and the burning character of the same samples is investigated thermogravimetrically. The moisture, ash and volatile matter analyses are also performed. An increase in carbonization temperature leads to a decrease in the amount of volatile matter. The differences between the effects of volatile matter on the ignition temperature and the gasification reactivity of the samples with CO2 might be explained by the change in pore structure and the varying catalytic effect of mineral components in the structure. It is also seen that there is a good correlation between the thermal analysis and the complete analysis results of the samples

  13. Dynamic single particle char combustion and its influence on the fate of fuel bound nitrogen. Numerical modelling and experiments

    International Nuclear Information System (INIS)

    A numerical char combustion model has been developed and an experimental investigation of the dynamic single char particle combustion process has been made. The numerical model calculates the temperature and gas concentration profiles of O2, CO, CO2, N2, H2O, NO and N2O in the particle interior and its boundary layer throughout the dynamic carbon conversion process. The experimental investigation include on-line measurements of O2, CO, CO2, NO and particle temperature. The particle temperature was measured by using a two color pyrometer. Complete temperature histories were measured. The measurements show and the calculations confirm that considerable amounts of CO2 are formed heterogeneously. The fuel nitrogen conversions to NO and N2O are primarily determined by the combustion regime. The yields of NO and N2O are higher during kinetically controlled combustion than during diffusionally controlled combustion. Calculations show that the fuel nitrogen conversions to NO and N2O are decreased by an increase in total pressure. Experimentally achieved fuel nitrogen to NO conversions, 35-37% at 5.0 bar and 56-63% at 1.0 bar, and comparisons to calculations indicate that only a minor fraction of fuel nitrogen is converted to N2O. 77 refs, 35 figs, 12 tabs

  14. Swimming endurance of bull trout, lake trout, arctic char, and rainbow trout following challenge with Renibacterium salmoninarum

    Science.gov (United States)

    Jones, D.T.; Moffitt, C.M.

    2004-01-01

    We tested the swimming endurance of juvenile bull trout Salvelinus confluentus, lake trout S. namaycush, Arctic char S. alpinus, and rainbow trout Oncorhynchus mykiss at 9??C and 15??C to determine whether sublethal infection from a moderate challenge of Renibacterium salmoninarum administered months before testing affected the length of time fish could maintain a swimming speed of 5-6 body lengths per second in an experimental flume. Rainbow trout and Arctic char swam longer in trials than did bull trout or lake trout, regardless of challenge treatment. When we tested fish 14-23 weeks postchallenge, we found no measurable effect of R. salmoninarum on the swimming endurance of the study species except for bull trout, which showed a mixed response. We conducted additional trials with bull trout 5-8 weeks postchallenge to determine whether increasing the challenge dose would affect swimming endurance and hematocrit. In those tests, bull trout with clinical signs of disease and those exposed to the highest challenge doses had significantly reduced swimming endurance compared with unchallenged control fish. Fish hematocrit levels measured at the end of all swimming endurance tests varied among species and between test temperatures, and patterns were not always consistent between challenged and control fish.

  15. Odor and VOC Emissions from Pan Frying of Mackerel at Three Stages: Raw, Well-Done, and Charred

    Directory of Open Access Journals (Sweden)

    Jeong-Hyeon Ahn

    2014-11-01

    Full Text Available Many classes of odorants and volatile organic compounds that are deleterious to our wellbeing can be emitted from diverse cooking activities. Once emitted, they can persist in our living space for varying durations. In this study, various volatile organic compounds released prior to and during the pan frying of fish (mackerel were analyzed at three different cooking stages (stage 1 = raw (R, stage 2 = well-done (W, and stage 3 = overcooked/charred (O. Generally, most volatile organic compounds recorded their highest concentration levels at stage 3 (O, e.g., 465 (trimethylamine and 106 ppb (acetic acid. In contrast, at stage 2 (W, the lowest volatile organic compounds emissions were observed. The overall results of this study confirm that trimethylamine is identified as the strongest odorous compound, especially prior to cooking (stage 1 (R and during overcooking leading to charring (stage 3 (O. As there is a paucity of research effort to measure odor intensities from pan frying of mackerel, this study will provide valuable information regarding the management of indoor air quality.

  16. Oxy-fuel combustion kinetics and morphology of coal chars obtained in N2 and CO2 atmospheres in an entrained flow reactor

    OpenAIRE

    Gil Matellanes, María Victoria; Riaza Benito, Juan; Álvarez González, Lucía; Pevida García, Covadonga; Pis Martínez, José Juan; Rubiera González, Fernando

    2012-01-01

    The thermal reactivity and kinetics of four coal chars (HVN, UM, SAB and BA) in an oxy-fuel combustion atmosphere (30%O2–70%CO2) were studied using a thermobalance. The coal chars were obtained by devolatilization in an entrained flow reactor (EFR) at 1000 °C for 2.5 s under 100% N2 and CO2 atmospheres. The reactivity tests were carried out by isothermal thermogravimetric analysis at different temperatures in a kinetically controlled regime. Three nth-order representative gas–solid models – t...

  17. TRP0033 - PCI Coal Combustion Behavior and Residual Coal Char Carryover in the Blast Furnace of 3 American Steel Companies during Pulverized Coal Injection (PCI) at High Rates

    Energy Technology Data Exchange (ETDEWEB)

    Veena Sahajwalla; Sushil Gupta

    2005-04-15

    Combustion behavior of pulverized coals (PC), gasification and thermal annealing of cokes were investigated under controlled environments. Physical and chemical properties of PCI, coke and carbon residues of blast furnace dust/sludge samples were characterized. The strong influence of carbon structure and minerals on PCI reactivity was demonstrated. A technique to characterize char carryover in off gas emissions was established.

  18. Chemical structures of swine-manure chars produced under different carbonization conditions investigated by advanced solid-state 13C nuclear magnetic resonance (NMR) spectroscopy

    Science.gov (United States)

    Two types of swine manure chars, hydrothermally-produced hydrochar and slow-pyrolysis pyrochar, and their raw swine manure solid were characterized using advanced 13C solid-state nuclear magnetic resonance (NMR) spectroscopy. Compared with the parent raw swine manure, both hydrochars and pyrochar di...

  19. Analytical pyrolysis of synthetic chars derived from biomass with potential agronomic application (biochar). Relationships with impacts on microbial carbon dioxide production

    Science.gov (United States)

    A set of 20 biochar samples produced from the pyrolysis of different biomass feedstocks with potential applications as soil amendments were investigated by pyrolysis coupled to gas chromatography-mass spectrometry (Py-GC-MS). The yields of 38 pyrolysis products representative of charred (e.g., benze...

  20. Potential of aeration flow rate and bio-char addition to reduce greenhouse gas and ammonia emissions during manure composting

    DEFF Research Database (Denmark)

    Chowdhury, Md Albarune; de Neergaard, Andreas; Jensen, Lars Stoumann

    2014-01-01

    Aeration is an important factor influencing CO2, CH4, N2O and NH3 emissions from the composting process. Both CH4 and N2O are potent greenhouse gases (GHG) of high importance. Here, we examined the effects of high and low aeration rates together with addition of barley straw with and without bio...... composting hen manure and barley straw at low flow rates proved most effective in reducing cumulative NH3 and CH4 losses. Addition of bio-char in combination with barley straw to hen manure at both high and low flow rates reduced total GHG emissions (as CO2-equivalents) by 27-32% compared with barley straw...

  1. Caracterização dos produtos líquidos e do carvão da pirólise de serragem de eucalipto Characterization of liquid products and char from the pyrolysis of eucalyptus sawdust

    Directory of Open Access Journals (Sweden)

    Ayrton F. Martins

    2007-08-01

    Full Text Available This study proposes the low temperature pyrolysis as an alternative conversion process for residual biomass and for obtaining gaseous, liquid and solid chemical feedstocks. Using a bench electrical pyrolysis oven, four product fractions from eucalyptus sawdust were obtained: a gaseous one, two liquid (aqueous and oily, and a solid residue (char. These products were characterized by different analytical methods. The liquid fractions showed themselves as potential sources for input chemicals. The residual char revealed appreciable adsorption capability. The process demonstrated good efficiency, generating at least two fractions of great industrial interest: bio oil and char.

  2. SiteChar. Characterisation of European CO2 storage. Deliverable 8.4. Quantitative social site characterisations

    Energy Technology Data Exchange (ETDEWEB)

    Brunsting, S.; Mastop, E.A. [ECN Policy Studies, Energy research Centre of the Netherlands ECN, Amsterdam (Netherlands); Kaiser, M.; Zimmer, R. [Unabhaengiges Institut fuer Umweltfragen UfU, Berlin (Germany)

    2013-06-15

    This report describes the results of the last stage of the in-depth social site characterisation activities at two prospective CCS sites as part of the SiteChar project: a CCS onshore site and a CCS offshore site. The onshore site is the Zalecze and Zuchlow site application (Poland - WP5) and the offshore site is the North Sea Moray Firth site (UK - WP3). This deliverable describes the results from a repeated quantitative measurement of local awareness, knowledge, and perceptions of CCS at both sites using representative surveys. For comparison and discussion of all SiteChar WP8 results we refer to the final summary report D8.5. The 2nd survey showed some interesting results. First of all, awareness of CCS was still very low. While in the UK around half of the respondents had at least heard of local plans for CCS, in Poland this was only 21%. It seems that awareness in the UK was mostly induced by specific plans in the area that were abandoned in the course of the SiteChar project. Second, it seems that on the whole the local publics were rather positive about CCS. Most respondents expected a positive impact of CCS on the region. In the UK, arguments for that were mainly economic, while in Poland arguments were mainly related to environmental concerns. Although there are some worries about risks of leakage, especially at the onshore site in Poland, people think that authorities will properly regulate CCS and monitor the safety of CCS. Expectations were mostly that it would be good for the country and that it will help reach international targets for CO2 reduction and buy time to develop renewable energy. Respondents seemed uncertain about the costs of using CCS and whether the technique is ready for widespread use. Especially in Poland people seemed to agree that CCS is essential for tackling climate change. Most differences between the two sites may be attributed to the proximity of the site to the local community. The Polish site is onshore and therefore much

  3. Factors Affecting the Optimum Seeding Level of Coal or Char-Fired, Open-Cycle MHD Power Plants

    International Nuclear Information System (INIS)

    A study of the optimum seed level with ash-containing, seeded fuels was made using a mathematical model to determine the composition and amounts of the combustion products which included a slag phase and condensed seed compounds. The results indicate that: the mechanism of seed condensation is the formation of liquid alkali sulphate; the contamination of the liquid seed with silica occurs because silica condenses over approximately the same temperature range as the alkali sulphate; and the level of seed contamination with silica plays a major role in deciding the system seed level. This contamination is unavoidable due to the difficulty of separating the alkali from the glass-like slag by ordinary chemical or physical means. Therefore the silica remaining in the gas phase when the bulk of the slag is separated from the combustion products must be recycled to the system with the co-condensed seed. This increased silica lowers the combustion temperature because of the energy required for its volatilization. The important factors in establishing the steady-state silica level in the system are: (1) The air/fuel level. Lowering this parameter below stoichiometric requirements decreases the silica contamination and increases the electrical conductivity of the combustion products; (2) The nature of the fuel. Silica levels are in general higher for a char than for a coal fuel. This is compensated for to a degree,by the higher electrical conductivity of the combustion products from char; (3) The sulphur level of the fuel. The higher the sulphur level the higher the temperature at which seed condensation (as the sulphate) initiates hence the greater the fraction of silica remaining in the gas phase; (4) The silica content of the fuel: (5) The seeding level. The greater the seed/coal ratio, the higher the initiation temperature of seed condensation; (6) The type of seed. A non-sulphur-containing seed results in a lower initiation temperature of seed condensation; (7) The

  4. The thermal stability and pyrolysis mechanism of boron-containing phenolic resins: The effect of phenyl borates on the char formation

    International Nuclear Information System (INIS)

    Graphical abstract: - Highlights: • The thermal stability and pyrolysis mechanism of cured BPR are investigated. • The high char yield of BPR results from the formed phenyl borates during curing. • Boron oxide is formed on the surface of carbonized product during pyrolysis. • The formed boron oxide revealed the cleavage of O–C bonds from phenyl borates. • The graphitization degree and graphite crystallites of PR are improved by introducing boron. - Abstract: Boron-containing phenolic resin (BPR) is a kind of the ablative resins with high-performance. Due to the lack of the exact knowledge concerning the pyrolysis mechanism of BPR, its development and application are greatly impeded. In the present paper, the chemical structure of the cured BPR and its structural evolution at high temperatures are investigated to clarify the reason for the high char yield of BPR. The results indicate that the high char yield of BPR is mainly attributed to the phenyl borates formed during curing, which can block parts of phenolic hydroxyl groups, and effectively inhibit their thermal decomposition reaction. Boron oxide is formed on the surface of carbonization products by the cleavage of O–C bonds from phenyl borates via pyrolysis, which avoids the release of volatile carbon dioxide and reduces the development of micro-structural defects of carbonization products. Introducing boron into PR improves the graphitization degree and graphite crystallites of carbonization products, which promotes the formation of a more ordered glassy carbon during pyrolysis. This study provides a new vision for the understanding of the high char yield of BPR, which makes it possible to develop a new ablative resin through molecular design

  5. Energetic assessment of air-steam gasification of sewage sludge and of the integration of sewage sludge pyrolysis and air-steam gasification of char

    International Nuclear Information System (INIS)

    Thermo-chemical treatment of sewage sludge is an interesting option for recovering energy and/or valuable products from this waste. This work presents an energetic assessment of pyrolysis and gasification of sewage sludge, also considering the prior sewage sludge thermal drying and the gasification of the char derived from the pyrolysis stage. Experimental data obtained from pyrolysis of sewage sludge, gasification of sewage sludge and gasification of char (all of these performed in a lab-scale fluidized reactor) were used for the energetic calculations. The results show that the energy contained in the product gases from pyrolysis and char gasification is not enough to cover the high energy consumption for thermal drying of sewage sludge. Additional energy could be obtained from the calorific value of the pyrolysis liquid, but some of its properties must be improved facing towards its use as fuel. On the other hand, the energy contained in the product gas of sewage sludge gasification is enough to cover the energy demand for both the sewage sludge thermal drying and the gasification process itself. Furthermore, a theoretical study included in this work shows that the gasification efficiency is improved when the chemical equilibrium is reached in the process. - Highlights: • 4 MJ kg−1 for thermal drying of sewage sludge (SS) from 65 to 6.5 wt.% of moisture. • 0.15 MJ kg−1 for thermal decomposition of sewage sludge during fast pyrolysis. • Not enough energy in gases from SS pyrolysis and char gasification for thermal drying. • Enough energy in SS gasification gas for thermal drying and gasification process. • Gasification efficiency improves when equilibrium is reached in the process

  6. Effects of catalytic mineral matter CO/CO{sub 2} ratio on temperature and burning time for char combustion. Quarterly progress report No. 1, October--December 1989

    Energy Technology Data Exchange (ETDEWEB)

    Longwell, J.P.; Sarofim, A.F.; Tognotti, L.; Du, Zhiyou

    1989-12-31

    The temperature of a char particle burning in an oxygen containing atmosphere is the product of a strongly coupled balance between particle size and physical properties, heat transfer from the particle, surface reactivity, CO/CO{sub 2} ratio and gas phase diffusion in the surrounding boundary layer and within the particle. The heat released by formation Of CO{sub 2} is a factor of 3.5 higher than for CO so the temperature of a particle will depend strongly on the CO/CO{sub 2} ratio produced. If gas diffusion through the boundary layer is fast, increased direct production of CO{sub 2} produces a higher temperature and a higher burning rate. If the supply of oxygen to the surface is limited by diffusion through the boundary layer, production of CO{sub 2} consumes half as much carbon as production of CO so carbon consumption rate is reduced even though temperature may be somewhat higher. Models of these complex interaction have been developed; however, the CO/CO{sub 2} ratio produced by the carbon-oxygen reaction must, at present be assumed or inferred from measurement of particle temperature. CO/CO{sub 2} rates can be strongly influenced by catalytic material in the carbon and by the char temperature. In this program we are measuring the CO/CO{sub 2} ratio for both catalyzed and uncatalyzed chars over a wide range of temperature. These results will then be used to develop predictive models for char temperature and burning rates.

  7. The thermal stability and pyrolysis mechanism of boron-containing phenolic resins: The effect of phenyl borates on the char formation

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Shujuan; Wang, Yong; Bian, Cheng; Zhong, Yuhu [Department of Applied Chemistry, School of Science, Xi’an Jiaotong University, Xi’an 710049, People’ s Republic of China (China); Jing, Xinli, E-mail: rgfp-jing@mail.xjtu.edu.cn [Department of Applied Chemistry, School of Science, Xi’an Jiaotong University, Xi’an 710049, People’ s Republic of China (China); MOE Key Laboratory for Nonequilibrium Synthesis and Modulation of Condensed Matter, Xi’an, 710049, People’ s Republic of China (China)

    2015-03-15

    Graphical abstract: - Highlights: • The thermal stability and pyrolysis mechanism of cured BPR are investigated. • The high char yield of BPR results from the formed phenyl borates during curing. • Boron oxide is formed on the surface of carbonized product during pyrolysis. • The formed boron oxide revealed the cleavage of O–C bonds from phenyl borates. • The graphitization degree and graphite crystallites of PR are improved by introducing boron. - Abstract: Boron-containing phenolic resin (BPR) is a kind of the ablative resins with high-performance. Due to the lack of the exact knowledge concerning the pyrolysis mechanism of BPR, its development and application are greatly impeded. In the present paper, the chemical structure of the cured BPR and its structural evolution at high temperatures are investigated to clarify the reason for the high char yield of BPR. The results indicate that the high char yield of BPR is mainly attributed to the phenyl borates formed during curing, which can block parts of phenolic hydroxyl groups, and effectively inhibit their thermal decomposition reaction. Boron oxide is formed on the surface of carbonization products by the cleavage of O–C bonds from phenyl borates via pyrolysis, which avoids the release of volatile carbon dioxide and reduces the development of micro-structural defects of carbonization products. Introducing boron into PR improves the graphitization degree and graphite crystallites of carbonization products, which promotes the formation of a more ordered glassy carbon during pyrolysis. This study provides a new vision for the understanding of the high char yield of BPR, which makes it possible to develop a new ablative resin through molecular design.

  8. Combustion of char-coal waste pellets for high efficiency and low NO{sub x}. Technical report, March 1--May 31, 1995

    Energy Technology Data Exchange (ETDEWEB)

    Rajan, S.

    1995-12-31

    To maintain market share, new uses must be found for Illinois coals in the largest end use area, namely power generation. To this end, the suitability of Illinois coal for high efficiency power plants like combined cycles must be investigated. This approach involves partial gasification of the coal to produce fuel gas for the topping cycle gas turbines, while the residual char is burnt in the gas turbine exhaust to produce steam for the Rankine bottoming cycle. This project seeks to improve the combustion characteristics of the residual char by pelletizing it with waste coal in order to improve its combustor residence time and carbon conversion efficiency. At the same time, attempts are made to reduce pollutant emissions. During this quarter, the residual char produced by Foster Wheeler Development Corporation in their pyrolyzer has been pelletized with Illinois gob coal in various proportions. Combustion tests have been performed in a laboratory scale circulating fluidized bed combustor. Preliminary results show that the pellets are much easier to burn and exhibit high carbon conversion efficiencies. Further combustion tests are in progress.

  9. OPTIMIZATION OF SYNTHESIS AND CHARACTERIZATION OF PALM SHELL-BASED BIO-CHAR AS A BY-PRODUCT OF BIO-OIL PRODUCTION PROCESS

    Directory of Open Access Journals (Sweden)

    Arash Arami-Niya,

    2011-11-01

    Full Text Available In this study the optimum preparation conditions of bio-char were achieved as a by-product of the bio-oil production process from oil palm shell as an agricultural waste material. To investigate the possibility of utilizing bio-char as an adsorbent for wastewater treatment and other applications, a central composite design was applied to investigate the influence of carbonization temperatures, nitrogen flow rates, particle sizes of precursor, and duration on the bio-char yield and methylene blue adsorption capacity as the responses. Methylene blue was chosen in this study due to its wide application and known strong adsorption onto solids. Two quadratic models were developed for the responses and to calculate the optimum operating variables providing a compromise between yield and adsorption. From the analysis of variance, temperature was identified as the most influential factor on each experimental design response. The predicted yield and adsorption capacity was found to agree satisfactorily with the experimental values. A temperature of 400°C, nitrogen flow of 2.6 L/min, particle size of 1.7 mm and time of 61.42 min were found as the optimum preparation conditions and near to the optimal bio-oil production variables.

  10. Preliminary investigation on the production of fuels and bio-char from Chlamydomonas reinhardtii biomass residue after bio-hydrogen production.

    Science.gov (United States)

    Torri, Cristian; Samorì, Chiara; Adamiano, Alessio; Fabbri, Daniele; Faraloni, Cecilia; Torzillo, Giuseppe

    2011-09-01

    The aim of this work was to investigate the potential conversion of Chlamydomonas reinhardtii biomass harvested after hydrogen production. The spent algal biomass was converted into nitrogen-rich bio-char, biodiesel and pyrolysis oil (bio-oil). The yield of lipids (algal oil), obtained by solvent extraction, was 15 ± 2% w/w(dry-biomass). This oil was converted into biodiesel with a 8.7 ± 1% w/w(dry-biomass) yield. The extraction residue was pyrolysed in a fixed bed reactor at 350 °C obtaining bio-char as the principal fraction (44 ± 1% w/w(dry-biomass)) and 28 ± 2% w/w(dry-biomass) of bio-oil. Pyrolysis fractions were characterized by elemental analysis, while the chemical composition of bio-oil was fully characterized by GC-MS, using various derivatization techniques. Energy outputs resulting from this approach were distributed in hydrogen (40%), biodiesel (12%) and pyrolysis fractions (48%), whereas bio-char was the largest fraction in terms of mass. PMID:21345670

  11. Effect of reduction roasting by using bio-char derived from empty fruit bunch on the magnetic properties of Malaysian iron ore

    Institute of Scientific and Technical Information of China (English)

    Nurul A. Yunus; Mohd H. Ani; Hamzah M. Salleh; Rusila Z. A. Rashid; Tomohiro Akiyama; Hadi Purwanto; Nur E. F. Othman

    2014-01-01

    Beneficiation of Malaysian iron ore is becoming necessary as iron resources are depleting. However, the upgrading process is challenging because of the weak magnetic properties of Malaysian iron ore. In this study, bio-char derived from oil palm empty fruit bunch (EFB) was utilized as an energy source for reduction roasting. Mixtures of Malaysian iron ore and the bio-char were pressed into briquettes and subjected to reduction roasting processes at 873-1173 K. The extent of reduction was estimated on the basis of mass loss, and the mag-netization of samples was measured using a vibrating sample magnetometer (VSM). When reduced at 873 K, the original goethite-rich ore was converted into hematite. An increase in temperature to 1073 K caused a significant conversion of hematite into magnetite and enhanced the magnetic susceptibility and saturation magnetization of samples. The magnetic properties diminished at 1173 K as the iron ore was par-tially reduced to wustite. This reduction roasting by using the bio-char can assist in upgrading the iron ore by improving its magnetic proper-ties.

  12. Phosphate-induced metal stabilization: Use of apatite and bone char for the removal of soluble radionuclides in authentic and simulated DOE groundwater

    International Nuclear Information System (INIS)

    The apatite group of minerals is a family of calcium phosphate phases. Apatite is the principal component of bone tissue, and it also occurs naturally as mineral deposits in the geosphere. Bone char is calcined (coked) animal bone, containing activated carbon as well as calcium phosphate mineral phases. Apatite IItrademark is a more reactive form of apatite, supplied by UFA Ventures, Inc., at a cost of approximately 1/4 that of commercial bone char. Apatite is shown to be effective for the removal of select heavy metal impurities in groundwater. Previous investigations have demonstrated that apatite is an effective medium for the stabilization of soluble lead, cadmium, and zinc from mine waste leachate by the formation of highly insoluble precipitate phases. The performance of bone char and apatite II are compared with other candidate sorption media (including granular activated carbon and anion exchange resin) for the removal of soluble uranyl ion in synthetic DOE Site groundwater supplemented with varying levels of interfering nitrate ion. Apatite II has a greater affinity for U(VI), especially in the presence of nitrate ion, as evidenced by a larger value for the conditional distribution coefficient (Kd) in batch test experiments. Contact of uranyl nitrate solution with apatite II is shown to produce highly insoluble mineral phases of the autunite group (calcium uranyl phosphate hydrates). Apatite II is also demonstrated to be moderately effective for the removal of soluble radioactive isotopes of strontium, but not cesium, when these ions are supplemented into authentic DOE Site groundwater

  13. Effect of reduction roasting by using bio-char derived from empty fruit bunch on the magnetic properties of Malaysian iron ore

    Science.gov (United States)

    Yunus, Nurul A.; Ani, Mohd H.; Salleh, Hamzah M.; Rashid, Rusila Z. A.; Akiyama, Tomohiro; Purwanto, Hadi; Othman, Nur E. F.

    2014-04-01

    Beneficiation of Malaysian iron ore is becoming necessary as iron resources are depleting. However, the upgrading process is challenging because of the weak magnetic properties of Malaysian iron ore. In this study, bio-char derived from oil palm empty fruit bunch (EFB) was utilized as an energy source for reduction roasting. Mixtures of Malaysian iron ore and the bio-char were pressed into briquettes and subjected to reduction roasting processes at 873-1173 K. The extent of reduction was estimated on the basis of mass loss, and the magnetization of samples was measured using a vibrating sample magnetometer (VSM). When reduced at 873 K, the original goethite-rich ore was converted into hematite. An increase in temperature to 1073 K caused a significant conversion of hematite into magnetite and enhanced the magnetic susceptibility and saturation magnetization of samples. The magnetic properties diminished at 1173 K as the iron ore was partially reduced to wustite. This reduction roasting by using the bio-char can assist in upgrading the iron ore by improving its magnetic properties.

  14. Preparation of activated carbon from coconut shell chars in pilot-scale microwave heating equipment at 60 kW

    International Nuclear Information System (INIS)

    Experiments to prepare activated carbon by microwave heating indicated that microwave energy can decrease reaction temperature, save the energy and shorten processing time remarkably compared to conventional heating, owing to its internal and volumetric heating effects. The above results were based on the laboratory-scale experiments. It is desirable to develop a pilot-scale microwave heating equipment and investigate the parameters with the aim of technological industrialization. In the present study, the components and features of the self-invented equipment were introduced. The temperature rise curves of the chars were obtained. Iodine numbers of the activated carbons all exceed the state standard of China under the following conditions: 25 kg/h charging rate, 0.42 rev/min turning rate of ceramic tube, flow rate of steam at pressure of 0.01 MPa and 40 kW microwave heating power after 60 kW pre-activation for 30 min. Pore structure of the sample obtained at a time point of 46 h, which contained BET surface area, and pore size distributions of micropores and total pores, was tested by nitrogen adsorption at 77 K

  15. Production of bio-oil and bio-char from pyrolysis of oil palm empty fruit bunches (EFB)

    International Nuclear Information System (INIS)

    The fast pyrolysis of empty fruit bunches (EFB) was carried out using a fluidized-fixed bed reactor. An electric furnace heated the reactor with a heated length of 135 mm and an inner diameter of 40 mm. The sand bed was fluidized using argon at a rate of 0.5 litre per minute (LPM). The sand bed consisted of 100 g zircon sand of 180 - 250 μm. Several process parameters such as the pyrolysis temperature, particle size and different types of pre-treatment that can affect the yield of the pyrolysis products were investigated. The experiment of fast pyrolysis was conducted using 2 - 4 g of EFB which was fed into the reactor using argon at a rate of 2.5 LPM. The temperature used was in the range of 400-600 degree Celsius and particle size of EFB was 2SO4, NaOH and distilled water. The results indicated that the optimum yield of bio-oils was obtained using unwashed EFB having particle size of 91-106 μm at pyrolyzed temperature of 500 degree Celsius. The maximum yield of bio-char was obtained using washed EFB with NaOH at temperature of 600 degree Celsius and particle size of 106-125 μm. (author)

  16. Study of CO2 gasification characteristics on Hunyuan coal char%浑源煤焦的CO2气化特性研究

    Institute of Scientific and Technical Information of China (English)

    陈鸿伟; 吴亮; 高松; 韩亮; 索新良

    2011-01-01

    The reaction characteristics of Hunyuan coal chars with CO2 were investigated by means of isothermal gasification under different temperature from 750 ℃ ~950 ℃. The pyrolysis temperature, holding time, CO2 partial pressure and gasification temperature were analyzed for the effects on gasification characteristics. Hunyuan coal char shows good performance at the gasification temperature of 850 ℃. The gasification reaction activity decreases with gasification temperature. There is no remarkable difference between the 30 min char and the 50 min char, but there is a decrease in the reaction of 2 h char. The gasification reaction activity improves with the increase of CO2 partial pressure from 0. 05 -0. 1 Mpa. The activation energy is 126. 24 Kj/mol using half-time method, and the distributed activated energy model (DAEM) concretely describes the change of activation energy at different part of the reaction.%在750~950℃范围内,用等温气化的方法研究了热解温度、热解时间、CO2分压、气化温度等对浑源煤焦气化反应特性的影响.结果表明,浑源煤焦在850℃时的气化活性较好;随着制焦温度的提高,气化活性下降;30 main焦与50 main焦的气化活性无明显差异,而2h焦则表现出了随保温时间延长,气化活性降低的趋势;0.05~0.1 MPa范围内,煤焦的气化反应性随CO2分压的提高而提高;半衰期法计算的气化反应活化能为126.24 kJ/mol,分布活化能模型更加具体地反映了煤焦在不同反应阶段反应活性的变化规律.

  17. Syngas production by gasification of aquatic biomass with CO2/O2 and simultaneous removal of H2S and COS using char obtained in the gasification

    International Nuclear Information System (INIS)

    Applicability of gulfweed as feedstock for a biomass-to-liquid (BTL) process was studied for both production of gas with high syngas (CO + H2) content via gasification of gulfweed and removal of gaseous impurities using char obtained in the gasification. Gulfweed as aqueous biomass was gasified with He/CO2/O2 using a downdraft fixed-bed gasifier at ambient pressure and 900 °C at equivalence ratios (ER) of 0.1–0.3. The syngas content increased while the conversion to gas on a carbon basis decreased with decreasing ER. At an ER of 0.1 and He/CO2/O2 = 0/85/15%, the syngas content was maximized at 67.6% and conversion to gas on a carbon basis was 94.2%. The behavior of the desulfurization using char obtained during the gasification process at ER = 0.1 and He/CO2/O2 = 0/85/15% was investigated using a downdraft fixed-bed reactor at 250–550 °C under 3 atmospheres (H2S/N2, COS/N2, and a mixture of gases composed of CO, CO2, H2, N2, CH4, H2S, COS, and steam). The char had a higher COS removal capacity at 350 °C than commercial activated carbon because (Ca,Mg)S crystals were formed during desulfurization. The char simultaneously removed H2S and COS from the mixture of gases at 450 °C more efficiently than did activated carbon. These results support this novel BTL process consisting of gasification of gulfweed with CO2/O2 and dry gas cleaning using self-supplied bed material. -- Highlights: • A product gas with high syngas content was produced from the gasification of gulfweed with CO2/O2. • The syngas content increased with decreasing the equivalence ratio. • The syngas content was maximized at 67.6% at an ER of 0.1 and He/CO2/O2 = 0/85/15%. • The char simultaneously removed H2S and COS from a mixture of gases at 450 °C efficiently

  18. Behaviour, capture and inertization of some trace elements during combustion of refuse-derived char from municipal solid waste

    Energy Technology Data Exchange (ETDEWEB)

    Vassilev, S.V.; Braekman-Danheux, C.; Laurent, P.; Thiemann, T.; Fontana, A. [Bulgarian Academy of Sciences, Sofia (Bulgaria). Central Lab. of Mineralogy and Crystallography

    1999-08-01

    An investigation of refuse-derived char (RDC) generated by thermolysis of municipal solid waste (MSW) was undertaken to elucidate the behaviour of some toxic and potentially toxic trace elements (Cr, Cu, Mn, Ni, Pb, Sb and Zn) plus Fe during combustion of RDC. About 87% of Sb, 66% of Pb, 60% of Cu and significant parts of Fe{gt}Zn{gt}Ni{gt}Mn{gt}Cr from the RDC are volatile at 1200{degree}C, and their behaviour in the temperature interval 500-1200{degree}C is characterized. The use of sorbents (zeolite, kaolinite, montmorillonite, coals enriched in kaolinite and calcite, and lime plus portlandite) for capture, solidification and inertization of the most volatile elements during combustion of RDC is also described. Perspective sorbents and inertants for a retention of the most volatile Pb, Sb and Cu in RDC ash are kaolinite and montmorillonite or coals enriched in these minerals. In addition, when there is an effective RDC washing (dechlorination and desulphurization), the use of sorbents for capture of some metals could be reduced or even avoided. Recommendations are given for RDC utilization and improvisation of the collection, separation procedures and removal efficiency of some heavy-metal, chloride and sulphate compounds from MSW and RDC prior to their use. The results show that a long-term strategy based on detailed understanding of the source, formation, behaviour and fate of the elements and their modes of occurrence in MSW, RDC and combustion waste residues is required in order to validate a perspective waste pyrolytic processes development. 55 refs., 3 figs., 6 tabs.

  19. Adding the combination of CNTs and MoS{sub 2} into halogen-free flame retarding TPEE with enhanced the anti-dripping behavior and char forming properties

    Energy Technology Data Exchange (ETDEWEB)

    Zhong, Yuhua; Li, Maolin; Zhang, Luchong; Zhang, Xuewei; Zhu, Songwei; Wu, Wei, E-mail: wuwei@ecust.edu.cn

    2015-08-10

    Highlights: • Introduction the combination of the CNTs and MoS{sub 2} into P–N flame retarding TPEE. • Binary synergists for P–N flame retardants in TPEE. • Increase of char yield and form the stable carbonaceous char. - Abstract: In this paper, the nanocomposites thermoplastic polyester-ether elastomer (TPEE) with phosphorus–nitrogen (P–N) flame retardants, carbon nanotubes (CNTs) and molybdenum disulfide (MoS{sub 2}) was prepared by melt blending. TPEE containing P–N flame retardant, CNTs and MoS{sub 2} achieved UL94 V-0 rating due to the better barrier effect of the special structure. The structure was supported by the result of rheological properties. The thermal stability was studied by thermal gravimetric analysis (TGA) and char residue characterization was investigated by SEM–EDX measurements. The results demonstrated that the combination of CNTs and MoS{sub 2} results in the increase of char yield and the formation of the thermally stable char which can effectively prevent in the dripping behavior during the burning process.

  20. Aesthetic Analysis of Mosques’ Ornamentation and Tiling in the Safavid Era: A Case Study of Sheikh Lotfollah, Char Bagh, and Shah Mosques in Isfahan

    OpenAIRE

    ORAK, Mehnoush; VASIGH, Behzad

    2015-01-01

     Abstract. Ornamentation in the Islamic architecture in addition to elegance, suggest other concepts such as pantheism and tiling considers an elegant method of ornamentation throughout Muslim’s world.In Safavid era seven-colored tiles were widely used in Isfahan palaces.The present study aims to analyze the ornamentation of mosques inSafavid era from an aesthetic point of view. Therefore, Shaikhlotfollah, Char Bagh and Shah Mosque of Isfahan are samples studied in a descriptive-analytical me...

  1. Properties and Developments of Combustion and Gasification of Coal and Char in a CO2-Rich and Recycled Flue Gases Atmosphere by Rapid Heating

    OpenAIRE

    Zhigang Li; Xiaoming Zhang; Yuichi Sugai; Jiren Wang; Kyuro Sasaki

    2012-01-01

    Combustion and gasification properties of pulverized coal and char have been investigated experimentally under the conditions of high temperature gradient of order 200°C·s−1 by a CO2 gas laser beam and CO2-rich atmospheres with 5% and 10% O2. The laser heating makes a more ideal experimental condition compared with previous studies with a TG-DTA, because it is able to minimize effects of coal oxidation and combustion by rapid heating process like radiative heat transfer condition. The experim...

  2. Species interactions and response time to climate change: ice-cover and terrestrial run-off shaping Arctic char and brown trout competitive asymmetries

    Science.gov (United States)

    Finstad, A. G.; Palm Helland, I.; Jonsson, B.; Forseth, T.; Foldvik, A.; Hessen, D. O.; Hendrichsen, D. K.; Berg, O. K.; Ulvan, E.; Ugedal, O.

    2011-12-01

    There has been a growing recognition that single species responses to climate change often mainly are driven by interaction with other organisms and single species studies therefore not are sufficient to recognize and project ecological climate change impacts. Here, we study how performance, relative abundance and the distribution of two common Arctic and sub-Arctic freshwater fishes (brown trout and Arctic char) are driven by competitive interactions. The interactions are modified both by direct climatic effects on temperature and ice-cover, and indirectly through climate forcing of terrestrial vegetation pattern and associated carbon and nutrient run-off. We first use laboratory studies to show that Arctic char, which is the world's most northernmost distributed freshwater fish, outperform trout under low light levels and also have comparable higher growth efficiency. Corresponding to this, a combination of time series and time-for-space analyses show that ice-cover duration and carbon and nutrient load mediated by catchment vegetation properties strongly affected the outcome of the competition and likely drive the species distribution pattern through competitive exclusion. In brief, while shorter ice-cover period and decreased carbon load favored brown trout, increased ice-cover period and increased carbon load favored Arctic char. Length of ice-covered period and export of allochthonous material from catchments are major, but contrasting, climatic drivers of competitive interaction between these two freshwater lake top-predators. While projected climate change lead to decreased ice-cover, corresponding increase in forest and shrub cover amplify carbon and nutrient run-off. Although a likely outcome of future Arctic and sub-arctic climate scenarios are retractions of the Arctic char distribution area caused by competitive exclusion, the main drivers will act on different time scales. While ice-cover will change instantaneously with increasing temperature

  3. Emissions and Char Quality of Flame-Curtain "Kon Tiki" Kilns for Farmer-Scale Charcoal/Biochar Production.

    Directory of Open Access Journals (Sweden)

    Gerard Cornelissen

    Full Text Available Pyrolysis of organic waste or woody materials yields charcoal, a stable carbonaceous product that can be used for cooking or mixed into soil, in the latter case often termed "biochar". Traditional kiln technologies for charcoal production are slow and without treatment of the pyrolysis gases, resulting in emissions of gases (mainly methane and carbon monoxide and aerosols that are both toxic and contribute to greenhouse gas emissions. In retort kilns pyrolysis gases are led back to a combustion chamber. This can reduce emissions substantially, but is costly and consumes a considerable amount of valuable ignition material such as wood during start-up. To overcome these problems, a novel type of technology, the Kon-Tiki flame curtain pyrolysis, is proposed. This technology combines the simplicity of the traditional kiln with the combustion of pyrolysis gases in the flame curtain (similar to retort kilns, also avoiding use of external fuel for start-up.A field study in Nepal using various feedstocks showed char yields of 22 ± 5% on a dry weight basis and 40 ± 11% on a C basis. Biochars with high C contents (76 ± 9%; n = 57, average surface areas (11 to 215 m2 g-1, low EPA16-PAHs (2.3 to 6.6 mg kg-1 and high CECs (43 to 217 cmolc/kg(average for all feedstocks, mainly woody shrubs were obtained, in compliance with the European Biochar Certificate (EBC.Mean emission factors for the flame curtain kilns were (g kg-1 biochar for all feedstocks; CO2 = 4300 ± 1700, CO = 54 ± 35, non-methane volatile organic compounds (NMVOC = 6 ± 3, CH4 = 30 ± 60, aerosols (PM10 = 11 ± 15, total products of incomplete combustion (PIC = 100 ± 83 and NOx = 0.4 ± 0.3. The flame curtain kilns emitted statistically significantly (p<0.05 lower amounts of CO, PIC and NOx than retort and traditional kilns, and higher amounts of CO2.With benefits such as high quality biochar, low emission, no need for start-up fuel, fast pyrolysis time and, importantly, easy and cheap

  4. Emissions and Char Quality of Flame-Curtain "Kon Tiki" Kilns for Farmer-Scale Charcoal/Biochar Production

    Science.gov (United States)

    Cornelissen, Gerard; Pandit, Naba Raj; Taylor, Paul; Pandit, Bishnu Hari; Sparrevik, Magnus; Schmidt, Hans Peter

    2016-01-01

    Flame Curtain Biochar Kilns Pyrolysis of organic waste or woody materials yields charcoal, a stable carbonaceous product that can be used for cooking or mixed into soil, in the latter case often termed "biochar". Traditional kiln technologies for charcoal production are slow and without treatment of the pyrolysis gases, resulting in emissions of gases (mainly methane and carbon monoxide) and aerosols that are both toxic and contribute to greenhouse gas emissions. In retort kilns pyrolysis gases are led back to a combustion chamber. This can reduce emissions substantially, but is costly and consumes a considerable amount of valuable ignition material such as wood during start-up. To overcome these problems, a novel type of technology, the Kon-Tiki flame curtain pyrolysis, is proposed. This technology combines the simplicity of the traditional kiln with the combustion of pyrolysis gases in the flame curtain (similar to retort kilns), also avoiding use of external fuel for start-up. Biochar Characteristics A field study in Nepal using various feedstocks showed char yields of 22 ± 5% on a dry weight basis and 40 ± 11% on a C basis. Biochars with high C contents (76 ± 9%; n = 57), average surface areas (11 to 215 m2 g-1), low EPA16—PAHs (2.3 to 6.6 mg kg-1) and high CECs (43 to 217 cmolc/kg)(average for all feedstocks, mainly woody shrubs) were obtained, in compliance with the European Biochar Certificate (EBC). Gas Emission Factors Mean emission factors for the flame curtain kilns were (g kg-1 biochar for all feedstocks); CO2 = 4300 ± 1700, CO = 54 ± 35, non-methane volatile organic compounds (NMVOC) = 6 ± 3, CH4 = 30 ± 60, aerosols (PM10) = 11 ± 15, total products of incomplete combustion (PIC) = 100 ± 83 and NOx = 0.4 ± 0.3. The flame curtain kilns emitted statistically significantly (pemission, no need for start-up fuel, fast pyrolysis time and, importantly, easy and cheap construction and operation the flame curtain technology represent a promising

  5. Influence of silica on physicochemical characteristic of modified bio-chars%SiO2对改性生物质焦理化特性的影响

    Institute of Scientific and Technical Information of China (English)

    冯烨; 米铁; 张雄; 杨海平; 王贤华; 张世红; 陈汉平

    2014-01-01

    To study the effect of SiO2 on the physicochemical characteristic of modified biochar, bio-chars were obtained at 600℃in a vertical furnace from a pyrolysis of rice straw, cotton stalk, and rice husk. Bio-chars were activated at different temperatures (400, 600, 800, and 1 000℃) in a gaseous NH3 and/or CO2 atmosphere. The variation of chemical properties, the CO2 adsorption capacities, and the physicochemical properties linked with an ash analysis of different raw chars and modified chars were investigated. An X-ray fluorescence (EARGE Ⅲ, EDAX Inc.) and an ion chromatograph (ICS-90, Dionex) were used according to the national standard of GB/T1574 to analyze the ash composition of pyrolytic biochars. The content of SiO2 in rice husk char (87.47%) was the highest among the studied samples, followed by rice straw and cotton stalk chars, which were 51.99%and 18.21%, respectively. However, according to the proximate analysis of biomass raw materials, the proportion of ash in rice straw and rice husk was about 2-3 times of that of cotton stalk, therefore, the amount of SiO2 retained in rice husk and rice straw was nearly 15 times and 4-5 times of that in cotton stalk, respectively. The production and modification of biomass chars were carried out in a self-designed vertical furnace reaction system which included two parts: A gas generating zone and a modification reaction zone. The modification reaction zone mainly consisted of a stainless steel reactor (inner diameter 38 mm, outer diameter 40mm, and height 600 mm) and a temperature programmed furnace.A Fourier transform infrared spectrum analyzer (VERTEX70, Bruker) was used to analyze the variation of chemical properties and surface functional groups of biochars before and after NH3 modification at different temperatures. And the Fourier transform infrared spectra of the corresponding biomass raw materials linked with a proximate and ultimate analysis were also presented to compare with that of chars and modified

  6. Charred by charcoal

    OpenAIRE

    Ali, Taskeen

    2014-01-01

    A boy borne down with charcoal on his chukudu (home-made cycle), Goma. In an environment where the rebel groups have established a shadow state and economy in a political economy framed by war, charcoal as a necessity is traded every day in Goma, Eastern Democratic Republic of Congo. It is this charcoal trading that allows the boy to survive; it then bites back with violence that is financed by the very same things. In contrast to existing scholarship on internationally traded high value comm...

  7. Influence of reaction conditions and the char separation system on the production of bio-oil from radiata pine sawdust by fast pyrolysis

    Energy Technology Data Exchange (ETDEWEB)

    Park, Hyun Ju; Park, Young-Kwon; Kim, Joo Sik [Faculty of Environmental Engineering, University of Seoul, 90 Jeonnong-Dong, Dondaemun-Gu, Seoul 130-743 (Korea)

    2008-08-15

    Radiata pine sawdust was pyrolyzed in a bubbling fluidized bed equipped with a char separation system. The influence of the reaction conditions on the production of bio-oil was investigated through the establishment of mass balance, and the examination of the products' chemical and physical characteristics. The optimal reaction temperature for the production of bio-oil was between 673 and 723 K, and the yield was above 50 wt.% of the product. An optimal feed size also existed. In a particle with a size that was less than 0.3 mm, the bio-oil yield decreased due to overheating, which led to gas formation. A higher flow rate and feeding rate were found to be more effective for the production of bio-oil, but did not significantly affect it. The main compounds of bio-oil were phenolics, including cresol, guaiacol, eugenol, benzendiol and their derivatives, ketones, and aldehydes. In addition, high-quality bio-oils, which contained less than 0.005 wt.% of solid, no ash and low concentrations of alkali and alkaline earth metals, were produced due to the char removal system. (author)

  8. Chemical evaluation of chars produced by thermochemical conversion (gasification, pyrolysis and hydrothermal carbonization) of agro-industrial biomass on a commercial scale

    International Nuclear Information System (INIS)

    Technologies for agro-industrial feedstock utilization such as pyrolysis, gasification and hydrothermal carbonization at industrial scale develop rapidly. The thermochemically converted biomasses of these production technologies have fundamentally different properties controlled by the production technology. This is reflected by general properties such as pH or elemental composition. The 13C NMR spectroscopy, scanning electron microscopy and energy-dispersive X-ray spectroscopy and black carbon results confirmed these observations showing that hydrochars have lower proportions of aromatic compounds than biochars (less stable) but are rich in functional groups (higher cation exchange capacity) than biochars. Analyses of pollutants indicate that polycyclic aromatic hydrocarbons as well as dioxin contents of most samples were under the threshold values recommended by International Biochar Initiative and European Biochar Certificate. In conclusion, biochars and hydrochars are entirely different from each other and these materials will probably have a complementary reaction in a soil environment. -- Highlights: • Production technologies influences fundamentally chemical properties of chars. • Carbonized materials have different behaviour in soil environment. • Environmental risk of chars is low with respect to PAH and dioxin contents. • Certification standard for biochars is not suitable for hydrochars. • Commercial scale reactors are able to produce high quality biochars according to the regulations of the EBC or IBI

  9. Application of noncatalytic gas-solid reactions for a single pellet of changing size to the modeling of fluidized-bed combustion of coal char containing sulfur

    Energy Technology Data Exchange (ETDEWEB)

    Rehmat, A.; Saxena, S.C.; Land, R.H.

    1980-09-01

    A mechanistic model is developed for coal char combustion, with sulfur retention by limestone or dolomite sorbent, in a gas fluidized bed employing noncatalytic single pellet gas-solid reactions. The shrinking core model is employed to describe the kinetics of chemical reactions taking place on a single pellet; changes in pellet size as the reaction proceeds are considered. The solids are assumed to be in back-mix condition whereas the gas flow is regarded to be in plug flow. Most char combustion occurs near the gas distributor plate (at the bottom of the bed), where the bubbles are small and consequently the mass transfer rate is high. For such a case, the analysis is considerably simplified by ignoring the bubble phase since it plays an insignificant role in the overall rate of carbon conversion. Bubble-free operation is also encounterd in the turbulent regime, where the gas flow is quite high and classical bubbles do not exist. Formulation of the model includes setting up heat and mass balance equations pertaining to a single particle (1) exposed to a varying reactant concentration along the height of the bed and (2) whose size changes during reaction. These equations are then solved numerically to account for particles of all sizes in the bed in obtaining the overall carbon conversion efficiency and resultant sulfur retention. In particular, the influence on sorbent requirement of several fluid-bed variables such as oxygen concentration profile, particle size, reaction rate for sulfation reaction, and suflur adsorption efficiency are examined.

  10. 棉秆和油菜秆热解焦炭的燃烧与吸附特性%Burning and adsorption characteristics of char obtained from pyrolysis of cotton stalk and rapeseed straw

    Institute of Scientific and Technical Information of China (English)

    刘标; 陈应泉; 孟海波; 姚宗路; 王贤华

    2014-01-01

    To study the characteristics of biochar products from biomass pyrolysis, cotton stalk and rapeseed straw were used as raw materials to prepare pyrolytic biochar samples under various temperatures (350, 550, 750, 950°C). The combustion characteristics, hydrating properties, CO2 adsorption characteristics, phenol adsorption characteristics and antioxidant abilities of different biochar samples (marked as CS350, CS550, CS750, CS950, RS350, RS550, RS750, RS950) were compared. A thermo gravimetric analyzer (STA409, NETZSCH) was used to investigate the combustion behavior of char. In the thermogravimetric experiment, approximately 10 mg of sample was heated in TG equipment at a heating rate of 20°C/min from room temperature to 900°C. TG-DTG tangent method was employed to determine the combustion characteristic indexes, including ignition temperature (Ti), burnout temperature (Tf) and the maximum mass loss rate (DTGmax). Results showed that theTi andTf value of char was increased with pyrolysis temperature increment, and CS550 and RS750 had better combustion characteristics due to their higher heating values and faster combustion rates, and they were appropriate for use as fuel char. Water absorption characteristics of char were conducted in a constant temperature and humidity box (Temperature: 30℃, Humidity: 90%), and an oven setting at 55℃ was used to test the dehydration characteristics of the chars. Gravimetric method was used to describe the water absorption and dehydration process of char and soil. The test results showed that CS350 and RS550 had higher water absorbing capacity and water retaining capacity than soil and other chars, and they were appropriate for biochar. CO2 adsorption characteristics of char were measured in an automatic adsorption equipment (Micromeritics, ASAP 2020, USA) at 273 K. Before the adsorption measurements, the sample was degassed at 150°C under a vacuum (pressure of 50 lmHg) for 10 h. The test results showed that the pyrolysis

  11. Measurement of gas species, temperatures, char burnout, and wall heat fluxes in a 200-MW{sub e} lignite-fired boiler at different loads

    Energy Technology Data Exchange (ETDEWEB)

    Li, Zhengqi; Jing, Jianping; Liu, Guangkui; Chen, Zhichao; Liu, Chunlong [School of Energy Science and Engineering, Harbin Institute of Technology, 92, West Dazhi Street, Harbin 150001 (China)

    2010-04-15

    We measured various operational parameters of a 200-MW{sub e}, wall-fired, lignite utility boiler under different loads. The parameters measured were gas temperature, gas species concentration, char burnout, component release rates (C, H and N), furnace temperature, heat flux, and boiler efficiency. Cold air experiments of a single burner were conducted in the laboratory. A double swirl flow pulverized-coal burner has two ring recirculation zones that start in the secondary air region of the burner. With increasing secondary air flow, the air flow axial velocity increases, the maximum values for the radial velocity, tangential velocity, and turbulence intensity all increase, and there are slight increases in the air flow swirl intensity and the recirculation zone size. With increasing load gas, the temperature and CO concentration in the central region of burner decrease, while O{sub 2} concentration, NO{sub x} concentration, char burnout, and component release rates of C, H, and N increase. Pulverized-coal ignites farther into the burner, in the secondary air region. Gas temperature, O{sub 2} concentration, NO{sub x} concentration, char burnout and component release rates of C, H, and N all increase. Furthermore, CO concentration varies slightly and pulverized-coal ignites closer. In the side wall region, gas temperature, O{sub 2} concentration, and NO{sub x} concentration all increase, but CO concentration varies only slightly. In the bottom row burner region the furnace temperature and heat flux increase appreciably, but the increase become more obvious in the middle and top row burner regions and in the burnout region. Compared with a 120-MW{sub e} load, the mean NO{sub x} emission at the air preheater exits for 190-MW{sub e} load increases from 589.5 mg/m{sup 3} (O{sub 2} = 6%) to 794.6 mg/m{sup 3} (O{sub 2} = 6%), and the boiler efficiency increases from 90.73% to 92.45%. (author)

  12. Risk assessment-led characterisation of the SiteChar UK north sea site for the geological storage of CO2

    International Nuclear Information System (INIS)

    Risk assessment-led characterisation of a site for the geological storage of CO2 in the UK northern North Sea was performed for the EU SiteChar research project as one of a portfolio of sites. Implementation and testing of the SiteChar project site characterisation work-flow has produced a 'dry-run' storage permit application that is compliant with regulatory requirements. A site suitable for commercial-scale storage was characterised, compatible with current and future industrial carbon dioxide (CO2) sources in the northern UK. Pre-characterisation of the site, based on existing information acquired during hydrocarbon exploration and production, has been achieved from publicly available data. The project concept is to store captured CO2 at a rate of 5 Mt per year for 20 years in the Blake Oil Field and surrounding Captain Sandstone saline aquifer. This commercial-scale storage of 100 Mt CO2 can be achieved through a storage scenario combining injection of CO2 into the oil field and concurrent water production down-dip of the field. There would be no encroachment of supercritical phase CO2 for more than two kilometres beyond the field boundary and no adverse influence on operating hydrocarbon fields provided there is pressure management. Components of a storage permit application for the site are presented, developed as far as possible within a research project. Characterisation and technical investigations were guided by an initial assessment of perceived risks to the prospective site and a need to provide the information required for the storage permit application. The emphasis throughout was to reduce risks and uncertainty on the subsurface containment of stored CO2, particularly with respect to site technical performance, monitoring and regulatory issues, and effects on other resources. The results of selected risk assessment-led site characterisation investigations and the subsequent risk reassessments are described together with their implications

  13. A first step towards identification of tannin-derived black carbon: Conventional pyrolysis (Py–GC–MS) and thermally assisted hydrolysis and methylation (THM–GC–MS) of charred condensed tannins

    NARCIS (Netherlands)

    Kaal, J.; Nierop, K.G.J.; Kraal, P.; Preston, C.M.

    2012-01-01

    Tannins account for a significant proportion of plant biomass and are likely to contribute to the residues formed by incomplete biomass combustion (black carbon, BC). Nonetheless, the molecular properties of thermally modified tannins have not been investigated in laboratory charring experiments. We

  14. Numerical Study on Effect of Fractal Pore Structure on Char Combustion Characteristics%孔隙分形结构对煤焦燃烧特性影响的数值研究

    Institute of Scientific and Technical Information of China (English)

    何威; 何榕; 王晓亮

    2011-01-01

    为了研究煤焦颗粒的分形结构对煤焦燃烧特性的影响,采用随机漫步的算法生成了2组具有相近孔隙率和比表面积,但分形维数不同的颗粒模型。从分子运动论的角度建立分形多孔介质中的扩散模型,用简单碰撞理论(simplecollision theory,SCT)模拟煤焦与氧气的气固反应。在不同温度下对不同煤焦颗粒模型的燃烧进行了数值模拟,由数值计算的结果得到了不同孔隙结构的煤焦颗粒对应的表观动力学参数。结果表明,煤焦颗粒的分形维数对煤焦的表观反应参数有显著影响,分形维数越大,煤焦表观燃烧反应系数越小,呈现指数关系。%In order to investigate the effect of the fractal dimensions of the char particles on the combustion characteristics of the coal char, two groups of numerical char particle models with similar porosity and specific surface areas but different fractal dimensions were generated by the random walk algorithm. The diffusion model in the fractal porous media was established based on the kinetic theory of gas molecules. The heterogeneous reaction of the coal char with oxygen was modeled by the simple collision theory (SCT). The combustions of the char particles with different fractal dimensions were simulated at different temperatures, and the corresponding apparent kinetic parameters were obtained from the simulation results. The results indicate that the fractal dimension of the char particle has a significant impact on the apparent kinetic parameters of the coal char combustion, larger fractal dimensions lead to smaller reaction coefficients, and there is an exponential relationship between them.

  15. Comparison of real waste (MSW and MPW) pyrolysis in batch reactor over different catalysts. Part II: contaminants, char and pyrolysis oil properties.

    Science.gov (United States)

    Miskolczi, Norbert; Ateş, Funda; Borsodi, Nikolett

    2013-09-01

    Pyrolysis of real wastes (MPW and MSW) has been investigated at 500°C, 550°C and 600°C using Y-zeolite, β-zeolite, equilibrium FCC, MoO3, Ni-Mo-catalyst, HZSM-5 and Al(OH)3 as catalysts. The viscosity of pyrolysis oils could be decreased by the using of catalysts, especially by β-zeolite and MoO3. Both carbon frame and double bound isomerization was found in case of thermo-catalytic pyrolysis. Char morphology and texture analysis showed more coke deposits on the catalyst surface using MSW raw material. Pyrolysis oils had K, S, P Cl, Ca, Zn, Fe, Cr, Br and Sb as contaminants; and the concentrations of K, S, P, Cl and Br could be decreased by the using of catalysts. PMID:23891947

  16. Oxy-coal combustion in an entrained flow reactor: Application of specific char and volatile combustion and radiation models for oxy-firing conditions

    DEFF Research Database (Denmark)

    Álvarez, L.; Yin, Chungen; Riaza, J.;

    2013-01-01

    The deployment of oxy-fuel combustion in utility boilers is one of the major options for CO2 capture. However, combustion under oxy-firing conditions differs from conventional air-firing combustion, e.g., in the aspect of radiative heat transfer, coal conversion and pollutants formation. In this...... work, a numerical study on pulverised coal combustion was conducted to verify the applicability and accuracy of several sub-models refined for oxy-fuel conditions, e.g., gaseous radiative property model, gas-phase combustion mechanism and heterogeneous char reaction model. The sub-models were...... implemented in CFD (Computational Fluid Dynamics) simulations of combustion of three coals under air-firing and various oxy-firing (21-35% vol O2 in O2/CO2 mixture) conditions in an EFR (entrained flow reactor). The predicted coal burnouts and gaseous emissions were compared against experimental results. A...

  17. Factors influencing high voltage performance of coconut char derived carbon based electrical double layer capacitor made using acetonitrile and propylene carbonate based electrolytes

    Science.gov (United States)

    Hu, Changzheng; Qu, Weiguo; Rajagopalan, Ramakrishnan; Randall, Clive

    2014-12-01

    Symmetric EDLCs made using high purity carbon electrodes derived from coconut char were tested using 1 M Tetraethylammonium hexafluorophosphate dissolved in two different solvents namely acetonitrile and propylene carbonate. The cell voltage of the capacitor made using propylene carbonate can be extended to 3.5 V and it exhibited good cycling and thermal stability upto 70 °C while the voltage was limited to below 3.0 V in acetonitrile. XPS analysis of the positive and negative electrodes of EDLCs post cycling showed that the primary degradation products were related to ring opening reactions in propylene carbonate based electrolytes while water played a key role in degradation of acetonitrile based EDLCs.

  18. Oxy-coal combustion in an entrained flow reactor: Application of specific char and volatile combustion and radiation models for oxy-firing conditions

    International Nuclear Information System (INIS)

    The deployment of oxy-fuel combustion in utility boilers is one of the major options for CO2 capture. However, combustion under oxy-firing conditions differs from conventional air-firing combustion, e.g., in the aspect of radiative heat transfer, coal conversion and pollutants formation. In this work, a numerical study on pulverised coal combustion was conducted to verify the applicability and accuracy of several sub-models refined for oxy-fuel conditions, e.g., gaseous radiative property model, gas-phase combustion mechanism and heterogeneous char reaction model. The sub-models were implemented in CFD (Computational Fluid Dynamics) simulations of combustion of three coals under air-firing and various oxy-firing (21–35% vol O2 in O2/CO2 mixture) conditions in an EFR (entrained flow reactor). The predicted coal burnouts and gaseous emissions were compared against experimental results. A good agreement between the simulations and experiments was achieved, indicating a good applicability and reliability of the refined sub-models and suitability of use of the experimentally derived kinetic data in coal devolatilisation and char oxidation sub-models. The sub-models and the practices implemented in this work can be used in large-scale oxy-fuel combustion processes for reliable design and optimization. - Highlights: • CFD (computational fluid dynamics) modelling predicted overall combustion and emissions under air- and oxy-firing conditions in an EFR. • Sub-models originally developed for air-firing were adapted for oxy-fuel combustion. • A very good agreement between simulation results and experimental data was achieved. • The refined JL 4-step global mechanism for gas-phase combustion improves flame temperature prediction. • Non-gray calculation of an appropriate oxy-fuel WSGGM is recommended to improve simulations of oxy-fuel combustion processes

  19. Influence of preparation conditions on the combustion reactivity of chars produced from the fast pyrolysis of biomass%生物质焦制备条件对其燃烧反应特性的影响

    Institute of Scientific and Technical Information of China (English)

    侯凯湖; J A DRAHUN; A V BRIDGWATER

    2005-01-01

    The influence of preparation conditions, such as pyrolysis temperature and feed moisture content, on the combustion reactivity of chars produced from spruce wood by the flash pyrolysis has been investigated using a thermogravimetric analyser (TGA). The chars were wood feed containing different moisture contents of 0, 7.0% and 11.3%. It was found that the reactivity of a char in chemical kinetic control regime increased with decreasing pyrolysis temperature, and the volatile matter (VM) content and H/C ratio in chars also increased with decreasing pyrolysis temperature. There may have a direct relationship between the reactivity of chars and the combination of VM and H/C. In addition, chars produced under lower pyrolysis temperature possess higher activation energy and are more sensitive to combustion temperature, compared with those produced under higher pyrolysis temperature. It was found that feed moisture content has only a minor influence on char reactivity but has a significant effect on the volatile material content of chars produced at higher pyrolysis temperatures. Finally, a simple power-law kinetic model that has been employed to properly describe the char combustion.%在热重分析仪上,研究了生物质焦的制备条件对其燃烧反应特性的影响.生物质焦由闪速裂解技术制得,裂解温度为 748K、773K和823K;原料含水质量分数为 0、7.0%和11.3%.研究发现,生物质焦中挥发性物质的质量分数和H/C质量比随裂解温度的增加而降低,其燃烧反应性随裂解温度的增加而降低;与高裂解温度条件下制得的生物质焦相比,低裂解温度条件下制得的生物质焦具有较高的反应活化能和对燃烧温度更敏感.原料含水量对生物质焦的燃烧反应特性影响很小;但对高裂解温度条件下制得的生物质焦中的挥发性组分含量有较大的影响.简化的生物质焦本征燃烧反应幂函数动力学模型可以很好地描述其燃烧行为.

  20. 污水处理工艺对污泥热解半焦热解特性的影响%Effect of wastewater treatment processes on the pyrolysis properties of the chars from sewage sludge pyrolysis

    Institute of Scientific and Technical Information of China (English)

    王俊; 解立平; 高建东; 曹占平

    2013-01-01

    The pyrolysis properties of five different pyrolysis chars,derived from the pyrolysis of five different sewage sludges from three wastewater treatment plants under 450 ℃ , were studied by thermal gravimetric analysis with a heating rate of 10 ℃/min in nitrogen atmosphere. The results show that the pyrolysis processes of the five chars all can be divided into four stages: the stages of water release, slow weight loss, volatile release and residue decomposition respectively. Both the anaerobic process of wastewater treatment processes and sludge anaerobic digestion make the organic compounds in char complicated. The sludge anaerobic digestion improves the pyrolysis property of char, but the processes of " anaerobic + aerobic" and "aerobic + anaerobic" in wastewater treatment processes make the properties decrease,in which the influence of " aerobic + anaerobic " on the pyrolysis property of sludge is different from that of char; the third stage of char pyrolysis corresponds to the fourth stage of the sludge pyrolysis to some degree. The pyrolysis mechanisms of the five chars have been studied with Coats-Redfern method. It indicates that the mechanism functions of the five chars are not identical each other, but the pyrolysis activation energies of chars are higher than that of sludges.%通过在升温速率10℃/min和氮气氛围下的热重实验,对来自3个污水处理厂的5种污泥在450℃下热解制得半焦的热解特性进行了研究.结果表明,5种半焦的热解过程均为水分析出、缓慢失重、挥发分析出和残余物分解4个阶段.污水处理工艺中的厌氧过程和污泥厌氧消化使半焦中的有机物复杂化;污泥厌氧消化改善了半焦的热解性能,污水处理工艺中的“厌氧+好氧”和“好氧+厌氧”过程则降低了半焦的热解性能,其中“好氧+厌氧”过程对半焦热解性能的影响异于其对污泥热解性能的影响;半焦热解时的第三阶段与污泥的第四阶段

  1. Biochemical stability of organic matter in soils amended with organic slow N-release fertilizer derived from charred plant residues and ammonoxidized lignin

    Science.gov (United States)

    Knicker, Heike; de la Rosa, José Maria; López Martín, María; Clemente Barragan, Reyes; Liebner, Falk

    2013-04-01

    As an important plant nutrient, N that has been removed from the soil by plant growth is replaced mainly by the use of synthetic fertilizers. Although this practice has dramatically increased food production, the unintended costs to the environment and human health due to surplus and inefficient application have also been substantial. Major losses of N to the environment can be minimized if "sustainable" agricultural practices are combined with reasonable fertilization. The latter can be achieved by applying slow N-release fertilizers. Here, the N is incorporated into an organic matrix, which after its amendment to soils, slowly decompose, allowing the liberation of the nutrient. Deriving from organic waste, such an amendment helps to efficiently recycle resources and increases the C sequestration potential of soils. However, in order to turn this approach into a successful strategy, the material has to be bioavailable but still sufficiently recalcitrant to ensure slow and controlled N-release. In the present study, we tested potential slow N-release fertilizers recycled from organic waste for their biochemical stability in soils. They comprised N-rich charred grass residues and N-lignin derived from waste of the pulp and paper industry and enriched in N by ammonoxidation. The substrates were mixed with soil of an Histic Humaquept and subsequently subjected to microbial degradation at 28°C in a Respicond IV Apparatus for 10 weeks. Additionally, soil material without organic amendment and soils mixed with lignin or charcoal both with and without KNO3 were included into the experiment. During the degradation experiment the CO2 production was determined on an hourly base. The degradation rate constants and the mean residence times were calculated using a double exponential decay model (pools with fast and slow turnover). Alterations of the chemical composition of the organic matter during degradation were studied by solid-state 13C NMR spectroscopy. First results

  2. Sintering behavior of flying slag particles in entrained-bed coal gasifiers. 3rd Report. Effect of soot on sintering behavior of flying slag particles; Kiryuso sekitan gas ka ro ni okeru hisan slag fun no shoketsu tokusei. 3. Char chu tansobun no slag shoketsu yokusei sayo

    Energy Technology Data Exchange (ETDEWEB)

    Ueda, A.; Kida, E. [Babcock Hitachi K.K., Tokyo (Japan)

    1997-05-25

    The effect of char addition on sintering behavior of flying slag particles in an entrained-bed coal gasifier was examined using four kinds of amorphous water-quenched slag obtained at the pilot plant of HYCOL. This plant was designed to gasify 50 tons of coal per day. The sintering temperatures of the four slags without char were all approximately 800{degree}C. However, Taiheiyo coal slag did not sinter at 900{degree}C when the char added. It was considered that the char collected by the cyclon was a mixture of soot and unburned coal particles and the soot prevented the slag from sintering. Therefore, the effect of soot on sintering behavior was clarified using carbon black as soot. SEM and EDX analyses showed that very small soot particles acted as a dispersant in the slag. 12 refs., 13 figs., 2 tabs.

  3. 不同煤阶热解半焦的FT-Raman光谱研究%FT-Raman spectroscopic characterisation of chars from the pyrolysis of coals of varying rank

    Institute of Scientific and Technical Information of China (English)

    Xiao-jiang Li; Chun-zhu Li

    2005-01-01

    A brown coal, a high-volatile bituminous coal and a low-volatile bituminous coal were pyrolysed at a slow heating rate in a thermogravimetric analyser. The char samples were deconvoluted with 10 Gaussian bands representing the typical structures found in highly disordered carbon materials. Both total Raman intensity (peak area) and the Raman band intensity ratios from spectral deconvolution are useful parameters for the description of the structural features of coal chars. While the chars from the brown coal,the high-volatile bituminous coal and the low-volatile bituminous coal differ significantly at lowpyrolysis temperatures (e.g.600℃), the differences diminish with increasing pyrolysis temperature to 800℃ or 900℃. The ion-exchangeable Na in brown coal affects the char-forming reactions taking place during pyrolysis.%在热天平上采用慢速升温制备了褐煤、高挥发分烟煤和低挥发分烟煤的半焦.采用FT-Raman光谱对半焦进行了分析.半焦800cm-1至1800cm-1的Raman光谱可分解为10个谱带,以表征高度无序炭材料中的典型结构.光谱和谱带的强度比都可用来描述半焦的结构特征.在600℃低温热解时,三种煤半焦的结构差异明显.随热解温度升至800℃或900℃,这种差别消失.褐煤中可交换的钠离子影响热解过程中的成焦反应.

  4. Agglomeration and reaction characteristics of various coal chars in fluidized-bed coal gasifier; Ryudoso sekitan gas ka ronai deno sekitan no gyoshu tokusei to hanno tokusei

    Energy Technology Data Exchange (ETDEWEB)

    Uemiya, S.; Aoki, K.; Mori, S.; Kojima, T. [Seikei University, Tokyo (Japan). Faculty of Engineering

    1996-10-28

    With relation to the coals delivered as common samples in the coal fundamental technology development project, an experimental study was conducted on agglomeration characteristics and reaction characteristics in the fluidized-bed coal gasifier. For the experiment, used was a fluidized bed gasifier inserted with a cone-shape dispersion plate with a nozzle in the center. After raising the temperature of the gasifier up to 773K, gasification was conducted sending to the gasifier air from the nozzle and steam from the dispersion plate. The mean particle diameter and gas concentration of chars were measured till the temperature reaches 1373K. As a result of the experiment, it was confirmed that the carbon conversion ratio increases with a decrease in coalification degree of the coal. Moreover, influence of the coal kind was markedly observed at the grid zone of the lower part of the bed, and it was clarified that the lower carbon content ratio the coal kind has, the faster the speed of CO formation and water gasification get. The agglomeration temperature of charcoal which is a product of the condensate is lower by as many as several hundred K than the point of softening, and it was considered to be necessary to study the relation with the temperature distribution in the bed. 3 refs., 3 figs., 1 tab.

  5. 生物质富氮热解联产高值含氮油炭的理化特性%Physicochemical properties of nitrogen rich in oil and char during biomass nitrogen-rich pyrolysis

    Institute of Scientific and Technical Information of China (English)

    闻明; 张世红; 邵敬爱; 陈应泉; 冯磊; 王贤华; 陈汉平

    2015-01-01

    Biomass is one of the most important renewable resources. Pyrolysis for producing high value added products provides additional value for biomass energy utilization. Through the introduction of exogenous nitrogen in biomass pyrolysis in nitrogen-rich conditions, it can get high value of nitrogen-containing products, i.e. nitrogen-rich char and oil. In this study, wood chips were used as raw materials. The experiment was carried out in a fixed bed reactor at 350 to 850℃, and the effect of temperature and impregnation ratio(5%, 10%, 15%, 20%) on products yields, compositions and characteristics were investigated. Firstly, wood chips were immersed in different mass fractions of urea solution, stirred for 12 hours with a magnetic mixer at room temperature. The woodchips was then separated from solution by filtration and was dried after for 24 hours in an oven. The dried woodchips was then gone through pyrolysis and the bio-oil obtained at different temperatures was analyzed by gas chromatography-mass spectrometry. Derived bio-oil and char were also analyzed for their compositions to trace nitrogen mass transfer. The surface physicochemical property of the char under nitrogen-rich conditions was characterized using a diffuse reflectance infrared spectroscopy and X-ray photoelectron spectroscopy. With the rise of impregnation ratio, the yield of char and bio-oil had little change. Temperature had a remarkable effect on the yield and nitrogen content of boichar and bio oil. Change of product yields was mainly due to the three components (cellulose, ligin and semicellulose) decomposing at different temperatures, and to the volatilization of the secondary cracking at high temperature. The GC-MS results indicated that after treated with urea solution, biomass pyrolysis oil contains large amounts of nitrogen-containing chemicals that can be used to refine high value-added chemical products. The nitrogen-containing chemicals in the bio-oil mainly include aromatic amine

  6. 水葫芦水热碳化过程中焦炭物化结构演变特性%Forming property of water hyacinth hydro-char physicochemical structure during hydrothermal carbonation

    Institute of Scientific and Technical Information of China (English)

    高英; 袁巧霞; 陈汉平; 王贤华

    2015-01-01

    以水葫芦为原料,利用高温高压反应釜对240℃、停留时间0.5~24.0 h下水热炭物化结构的演变特性进行分析.研究发现:不同停留时间下焦炭的产率及O/C和H/C原子比的范围分别为22.17%~31.67%,0.19~0.45和0.94~1.51,焦炭的热值范围为16.83~20.63 M J/kg .通过对焦炭进行分析测试,探讨水热炭的生成机理以及炭微球的形成机制,结果表明:4.0h后延长停留时间对焦炭的化学特性没有明显的影响;但是随着时间的进一步延长,水热炭却表现出较好的结构特性,可以观察到焦炭表面有大量微球的生成,具有典型的核壳结构,炭微球的表面含有大量的活性含氧官能团,内部则为低活性的含氧官能团;水热炭比表面积随着时间的延长先增大后减小.%Hydrothermal carbonization of water hyacinth was conducted in an autoclave from 0 .5 h to 24 .0 h at 240 ℃ ,the physicochemical characteristics of water hyacinth hydro‐char was investigated . T he results show that hydro‐char yield ,oxygen/carbon ratio ,and hydrogen/carbon ratio in all hydro‐char products are 22 .17% to 31 .67% ,0 .19 to 0 .45 ,and 0 .94 to 1 .51 ,respectively ,and higher heat‐ing value of hydro‐char products is 16 .83 to 20 .63 MJ/kg .To further investigate the hydrothermal formation mechanism and carbon microspheres formation mechanism ,it is indicated that there′s no significant change in the chemical properties of hydro‐char after 4 .0 h ,but with time increasing ,the hydro‐char show better structural characteristics . The surface generates a large number of micro‐spheres with a typical core‐shell structure and the surface of carbon microspheres contains large a‐mounts of reactive oxygen‐containing functional groups ,compares with low activity of the internal ox‐ygen‐containing functional groups ,and specific surface area increases first ,and then decreases

  7. SELECTION OF BIOMASS MATERIALS PRODUCING CHAR AND ANALYSIS OF CALORIC REQUIREMENT%生物质炭化原料选择及需热量分析

    Institute of Scientific and Technical Information of China (English)

    胡威; 胡建杭; 王华; 杨丽; 邓双辉; 李娟琴

    2012-01-01

    从生物质原料的工业分析结果和木质素含量两个角度出发,分析了二者对生物质炭化的影响.对生物质炭化原料进行选择,认为木材类生物质适合作为生物质炭化的原料,可加强对树木枝条、锯末及薪炭林的炭化;为实现生物质炭化的工业化,还应设计利用烟气余热等热源来热解生物质的换热器,这项设计需知道生物质热解需热量.运用热重-差示扫描(TG-DSC)同步热分析仪对选用的木屑进行热解实验并利用DSC曲线对木屑炭化需热量进行分析.结果表明,木屑炭化终温为500℃时(初始温度为40℃),需热量为491 kJ/kg.提出DSC曲线在工业用热解换热器传热设计和校核中的应用方法.%Biomass materials for producing char had been selected after analyzing the influences of the two aspects on biomass carbonization. The two aspects are respectively the results of proximate analysis and lignin content of biomass materials. Forest biomass is suitable for biomass carbonization. The use of forest branches, sawdust and fuel forest for carbonization should been strengthened. In order to realize industrialization of biomass carbonization, heat exchanges for biomass pyrolysis utilizing residual heat of the flue should been designed. It needs to know the caloric requirement of pyrolysis. TG-DSC simultaneous thermal analyzer was used for experiments of sawdust. The analysis of caloric requirement of biomass carbonization was made. When the carbonization temperature was 500 ℃(the initial temperature was 40 ℃), caloric requirement was 491 kJ/kg. This paper also pointed out a DSC curve's application method in heat transfer design and verification of heat exchange for biomass pyrolysis.

  8. Time resolved pyrolysis of char

    DEFF Research Database (Denmark)

    Egsgaard, Helge; Ahrenfeldt, Jesper; Henriksen, Ulrik Birk

    pyrolysis, and slow heating in direct combination with mass spectrometry, gas chromatography/mass spectrometry and flame ionization detection, respectively. Characteristic ions derived from the flash pyrolysis-gas chromatography/mass spectrometry data enable the release of volatiles to be time and, hence...

  9. Carborane Dopant Strengthens Pitch Char

    Science.gov (United States)

    Brown, D. Kyle

    1992-01-01

    Addition of small amount of soluble, organic boron compound to matrix precursor of carbon-fiber/carbon-matrix (carbon/carbon) composite increases strength and toughness of composite. Compound catalyzes graphitization of matrix, giving rise to greater degree of graphitization at lower processing temperature. Technique used to advantage in carbon/carbon materials requiring lower temperature processing, such as those with inhibited matrices or materials sensitive to changes in fiber properties.

  10. A scanning electron microscopy study of ash, char, deposits and fuels from straw combustion and co-combustion of coal and straw

    Energy Technology Data Exchange (ETDEWEB)

    Sund Soerensen, H.

    1998-07-01

    The SEM-study of samples from straw combustion and co-combustion of straw and coal have yielded a reference selection of representative images that will be useful for future comparison. The sample material encompassed potential fuels (wheat straw and grain), bottom ash, fly ash and deposits from straw combustion as well as fuels (coal and wheat straw), chars, bottom ash, fly ash and deposits from straw + coal co-combustion. Additionally, a variety of laboratory ashes were studied. SEM and CCSEM analysis of the samples have given a broad view of the inorganic components of straw and of the distribution of elements between individual ash particles and deposits. The CCSEM technique does, however, not detect dispersed inorganic elements in biomass, so to get a more complete visualization of the distribution of inorganic elements additional analyses must be performed, for example progressive leaching. In contrast, the CCSEM technique is efficient in characterizing the distribution of elements in ash particles and between ash fractions and deposits. The data for bottom ashes and fly ashes have indicated that binding of potassium to silicates occurs to a significant extent. The silicates can either be in the form of alumino-silicates or quartz (in co-combustion) or be present as straw-derived amorphous silica (in straw combustion). This process is important for two reasons. One is that potasium lowers the melting point of silica in the fly ash, potentially leading to troublesome deposits by particle impaction and sticking to heat transfer surfaces. The other is that the reaction between potassium and silica in the bottom ash binds part of the potassium meaning that it is not available for reaction with chlorine or sulphur to form KCl or K{sub 2}SO{sub 4}. Both phases are potentially troublesome because they can condense of surfaces to form a sticky layer onto which fly ash particles can adhere and by inducing corrosion beneath the deposit. It appears that in the studied

  11. Searching for long-term trends in prehistoric manuring practice. δ15N analyses of charred cereal grains from the 4th to the 1st millennium BC

    DEFF Research Database (Denmark)

    Kanstrup, Marie; Holst, M.K.; Jensen, Peter Mose;

    2014-01-01

    Current concepts of prehistoric manuring are founded on limited and mainly circumstantial evidence, giving rise to much ambiguity with respect to the onset of systematic use of manure to enhance cereal production. This paper reports carbon (C) and nitrogen (N) contents and isotopic compositions (δ......13C, δ15N) of charred grains of naked barley, emmer and spelt dating to the first four millennia of early agriculture in Denmark. The δ15N values ranged from c. 0.5‰–5.5‰, 0.5‰–6.0‰ and 1.5‰–8‰ for spelt, emmer and naked barley, respectively. This study represents the until now most comprehensive...

  12. Development of a high-performance coal-fired power generating system with pyrolysis gas and char-fired high temperature furnace (HITAF). Quarterly progress report 8, October--December 1993

    Energy Technology Data Exchange (ETDEWEB)

    1994-02-01

    A concept for an advanced coal-fired combined-cycle power generating system is currently being developed. The first phase of this three-phase program consists of conducting the necessary research and development to define the system, evaluating the economic and technical feasibility of the concept, and preparing an R&D plan to develop the concept further. The power generating system being developed in this project will be an improvement over current coal-fired systems. Goals have been specified that relate to the efficiency, emissions, costs, and general operation of the system. The system proposed to meet these goals is a combined-cycle system where air for a gas turbine is indirectly heated to approximately 1800{degrees}F in furnaces fired with coal-derived fuels and then directly heated in a natural-gas-fired combustor to about 2400{degrees}F. The system is based on a pyrolyzing process that converts the coal into a low-Btu fuel gas and char. The fuel gas is relatively clean, and it is fired to heat tube surfaces that are susceptible to corrosion and problems from ash deposition. In particular, the high-temperature air heater tubes, which will need to be a ceramic material, will be located in a separate furnace or region of a furnace that is exposed to combustion products from the low-Btu fuel gas only.

  13. Analysis on the Target Product from Sewage Sludge Pyrolysis and Experiments on Using the Char for Enhancing Plant Cultivation%污水污泥裂解目标产物及残焦促进植物生长的研究

    Institute of Scientific and Technical Information of China (English)

    宋学顶; 陈德珍; 王中慧; 何炜

    2011-01-01

    Characteristics of sewage sludge pyrolysis under low temperatures were studied and the influences of reaction temperature and moisture content on products distribution and their properties were also investigated with a purpose to select a proper target product.After a dissective comparison,char produced from the pyrolysis process was chosen as the target product and then its effect on plant cultivation was checked by using it to plant garlic when blended into normal soil;also its heavy metals contents and their transfer to the garlic were investigated.The primary research results showed that with the moisture content reduced to a certain level,char production was above 40% of sewage sludge when the pyrolysis process took place under 550℃;ash content of the char is around 60%-65%,but it is rich with nitrogen,phosphorus and potassium contents.The heavy metal contents in the char meet up with the limitations for land use,and the garlic stems planted in the soil blended with the char grew much faster than those planted in normal soil with their averaged height being 3-4 cm higher;however the heavy metal contents in the fast-growing garlic stems were a little higher than that in the normal ones,which was not suitable for edible plants.The results obtained suggested that char produced from sewage sludge pyrolysis process could be a target product arranged for land use especially for non-edible plant cultivation.%研究了污水污泥的低温裂解特性,考察了裂解终温和干燥到一定程度后污泥含水率对裂解产物分布及产物性质的影响,并分析了裂解产物中最合适的目标产物形式.经过分析比较,最终确定以污泥裂解残焦为目标产物并通过与普通土壤混拌进行了栽种大蒜和测试大蒜重金属浓度水平的实验,并考察残焦中重金属向植物迁移的情况.结果表明,干燥到一定程度的污水污泥在550℃下裂解时残焦的产率在40%以上,其中灰分含量在60%~65%之间,富

  14. OPTIMIZATION OF CHAR FOR NOx REMOVAL; FINAL

    International Nuclear Information System (INIS)

    Work performed for this study demonstrates that the temperature of treatment and the identity of the treatment gas both strongly impact the surface chemistry of activated carbon. Two commercial activated carbons were treated in either N(sub 2) or H(sub 2) at different temperatures up to 2600 C. Several techniques-including microcalorimetry, point of zero charge measurements, thermal desorption-were used to provide insight into important aspects of the chemical surface properties. The results show that activated carbons treated at high temperatures (ca. 950 C) in hydrogen will not react with oxygen and water at ambient temperatures; moreover, surfaces created in this fashion have stable properties in ambient conditions for many months. In contrast, the same carbons treated in an inert gas (e.g., N(sub 2)) will react strongly with oxygen and water at ambient temperatures. In the presence of platinum (or any other noble metal), stable basic carbons, which will not adsorb oxygen in ambient laboratory conditions, can be created via a relatively low-temperature process. Treatment at higher temperatures ( and gt;1500 C) produced increasingly stable surfaces in either N(sub 2) or H(sub 2). A structural model is proposed. To wit: Treatment at high temperatures in any gas will lead to the desorption of oxygen surface functionalities in the form of CO and/or CO(sub 2). Absent any atom rearrangement, the desorption of these species will leave highly unsaturated carbon atoms (''dangling carbons'') on the surface, which can easily adsorb O(sub 2) and H(sub 2)O. In an inert gas these ''dangling carbons'' will remain, but hydrogen treatments will remove these species and leave the surface with less energetic sites, which can only adsorb O(sub 2) at elevated temperatures. Specifically, hydrogen reacts with any highly unsaturated carbons in the surface to form methane. At temperatures greater than 1500 C (e.g., 1800 C, 2600 C), structural annealing takes place and the consequent growth in the size of graphene layers eliminates the highly energetic dangling carbon sites. The basicity of the surface originates from two types of Lewis base sites: the localized electron pairs at the edges of the graphene layers and the delocalized(pi) electrons on the basal planes. A hydrogen spillover mechanism was proposed here to explain the low-temperature process for the stable basic carbon. The role played by platinum (or any noble metal) is to produce atomic hydrogen, which spills over onto the carbon surface. This atomic hydrogen hydrogasifies the most reactive, unsaturated carbon atoms at far lower temperatures than molecular hydrogen, thus leading to surface stabilization at relatively low temperatures

  15. KINETICS AND MECHANISMS OF NOx - CHAR REDUCTION

    Energy Technology Data Exchange (ETDEWEB)

    Suuberg, E.M.

    1998-06-19

    This study was undertaken in order to improve understanding of several aspects of the NO-carbon reaction. This reaction is of practical importance in combustion systems, but its close examination also provides some fundamental insight into oxidizing gas-carbon reactions. As part of this study, a comprehensive literature review of earlier work on this reaction has been published (Aarna and Suuberg, Fuel, 1997, 76, 475-491). It has been thought for some time that the kinetics of the NO-carbon reaction are unusual, in that they often show a two-regime Arrhenius behavior. It has, however, turned out during this work that NO is not alone in this regard. In this laboratory, we also uncovered evidence of two kinetic regime behavior in CO{sub 2} gasification. In another laboratory, a former colleague has identified the same behavior in N{sub 2}O. The low temperature reaction regime always shows an activation energy which is lower than that in the high temperature regime, leaving little doubt that a shift in mechanism, as opposed to transport limitations, dictates the behavior. The activation energy of the low temperature regime of these reactions is typically less than 100 kJ/mol, and the activation energy of the high temperature regime is generally considerably in excess of this value. In this study, we have resolved some apparent inconsistencies in the explanation of the low temperature regime, whose rate has generally been ascribed to desorption-controlled processes. Part of the problem in characterization of the different temperature regimes is that they overlap to a high degree. It is difficult to probe the low temperature regime experimentally, because of slow relaxation of the surface oxides in that regime. Using careful experimental techniques, we were able to demonstrate that the low temperature regime is indeed characterized by zero order in NO, as it must be. A separate study is being carried out to model the behavior in this regime in NO and in other gases, and the results will be presented shortly.

  16. Medicaid CHIP Environmental Scanning and Program Char...

    Data.gov (United States)

    U.S. Department of Health & Human Services — ESPC development is sponsored by the CMS Center for Medicare and Medicaid Innovation in partnership with the Center for Medicaid and CHIP Services (CMCS) under the...

  17. O2/CO2气氛下CO2和H2O气化反应对煤及煤焦燃烧特性的影响%Effect of CO2 and H2O gasification on the combustion characteristics of coal and char under O2/CO2 atmosphere

    Institute of Scientific and Technical Information of China (English)

    雷鸣; 黄星智; 王春波

    2015-01-01

    The burning behaviors of Datong coal and char under O2/N2 , O2/CO2 and O2/H2 O/CO2 atmosphere were comparatively investigated by thermogravimetric analyzer. The influence of CO2 and H2 O gasification on the oxy-fuel combustion characteristics of coal and char were mainly studied. The results indicate that at 5%oxygen concentration the burning rate of pulverized coal in each atmosphere decreases in the order of O2/N2 , O2/CO2 and O2/H2 O/CO2 . When the oxygen concentration reduces to 2%, owing to the CO2 and H2 O gasification, the overall reaction rate of pulverized coal increases in the same order at high temperatures. The burning rate of char is slower in O2/CO2 than that in O2/N2 at 5% oxygen concentration, but as the burning process is delayed, the overall reaction rate of char in O2/H2 O/CO2 rises significantly due to the action of gasification. At 2% oxygen concentration, the overall reaction rate of char in O2/CO2 is higher than the burning rate of char in O2/N2 with the rise in temperature. The overall reaction rate of char in O2/H2 O/CO2 further increases because the H2 O gasification plays a major role in CO2 and H2 O co-gasification. The kinetic analysis shows that at 5% oxygen concentration the apparent activation energy in the atmosphere increases in the order of O2/N2 , O2/CO2 and O2/H2 O/CO2 . However, the apparent activation energy of different atmospheres declines with the decrease of oxygen concentration.%利用热天平对比研究了大同煤及煤焦在O2/N2、O2/CO2 和O2/H2O/CO2 中的燃烧行为,探讨CO2 和H2O气化反应对其富氧燃烧特性的影响. 结果表明,在5%氧气浓度下,煤粉在O2/N2、O2/CO2 和O2/H2 O/CO2 中的燃烧速率按顺序依次降低. 氧气浓度降低到2%,由于CO2 和H2 O气化反应的作用,煤粉在高温区的整体反应速率按顺序依次增大. 当氧气浓度为5%时,煤焦在O2/CO2 中的燃烧速率要低于 O2/N2 中的燃烧速率,但燃烧反应推迟后气化反

  18. Effect of Ash on Oxygen Carriers for the Application of Chemical Looping Combustion to a High Carbon Char Effet des cendres sur l’activité des porteurs d’oxygène dans la combustion du charbon en boucle chimique

    Directory of Open Access Journals (Sweden)

    Rubel A.

    2011-02-01

    Full Text Available The application of Chemical Looping Combustion (CLC to solid fuels is being investigated at the University of Kentucky, Center for Applied Energy Research (CAER with the aim of the development of a Pressurized Chemical Looping Combustion/Gasification (PCLC/G process for the generation of electricity from coal. One important aspect of the CLC of solid fuel is the understanding of the effect of ash on the reactivity of Oxygen Carriers (OCs. The effect of ash on the redox capabilities of two different iron oxide OCs and on their ability to oxidize coal char was studied. To determine the effect of ash on the reactivity and recycle of the OCs through multiple redox cycles, fly ash from a coal-fired power plant was used. These experiments were performed in a TGMS system using 500 mg of ash/OC mixtures containing different ash concentrations up to 75%. The reducing gas was composed of 10% H2, 15% CO, 20% CO2, and a balance of Ar and the oxidizing gas was 20% O2 in Ar. Oxidation/reductions were carried to near completion. The ash was found to contain OC activity related to inherent iron present in the ash confirmed by XRD. This resulted in increased weight gain/loss on oxidation/reduction. The rate of oxidation/reduction increased with ash concentration due to increased porosity of the OC/ash mixture and better access of the reactive gases to the OC target sites. The two OCs were then used to combust a beneficiated coal char in the TGMS with the only oxygen supplied by an iron oxide OC. The starting mixture was 10% char and 90% of one of two OCs studied. The spent material containing reduced OC and ash was re-oxidized and 10% more char was added for a second reduction of the OC and oxidation of the added char. This procedure was repeated for 5 cycles increasing the ash concentrations from 5 to 25% in the char/ash/OC mixture. Carbon removal was 92 to 97.8 and 97.3 to 99.7% for the two different iron oxide OCs tested. Ash was not detrimental to the

  19. Formation of a dinuclear copper(II) complex through the cleavage of Cchar description='Single-Bond' name='Single-Bond' value='Single-Bond'/>N bond of 1-benzoyl-3-(pyridin-2-yl)-1H-pyrazole

    Energy Technology Data Exchange (ETDEWEB)

    Shardin, Rosidah; Pui, Law Kung; Yamin, Bohari M. [School of Chemical Sciences and Food Technology, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, UKM 43600 Bangi, Selangor (Malaysia); Kassim, Mohammad B. [School of Chemical Sciences and Food Technology, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, UKM 43600 Bangi, Selangor, Malaysia and Fuel Cell Institute, Universiti Kebangsaan Malaysia, UKM 43600 Bangi, Selangor (Malaysia)

    2014-09-03

    A simple mononuclear octahedral copper(II) complex was attempted from the reaction of three moles of 1-benzoyl-3-(pyridin-2-yl)-1H-pyrazole and one mole of copper(II) perchlorate hexahydrate in methanol. However, the product of the reaction was confirmed to be a dinuclear copper(II) complex with μ-(3-(pyridin-2-yl)-pyrazolato) and 3-(pyridin-2-yl)-1H-pyrazole ligands attached to each of the Cu(II) centre atom. The copper(II) ion assisted the cleavage of the C{sub benzoyl}char description='Single-Bond' name='Single-Bond' value='Single-Bond'/>N bond afforded a 3-(pyridin-2-yl)-1H-pyrazole molecule. Deprotonation of the 3-(pyridin-2-yl)-1H-pyrazole gave a 3-(pyridin-2-yl)-pyrazolato, which subsequently reacted with the Cu(II) ion to give the (3-(pyridin-2-yl)-pyrazolato)(3-(pyridin-2-yl)-1H-pyrazole)Cu(II) product moiety. The structure of the dinuclear complex was confirmed by x-ray crystallography. The complex crystallized in a monoclinic crystal system with P2(1)/n space group and cell dimensions of a = 12.2029(8) Å, b = 11.4010(7) Å, c = 14.4052(9) Å and β = 102.414(2)°. The compound was further characterized by mass spectrometry, CHN elemental analysis, infrared and UV-visible spectroscopy and the results concurred with the x-ray structure. The presence of d-d transition at 671 nm (ε = 116 dm{sup 3} mol{sup −1} cm{sup −1}) supports the presence of Cu(II) centres.

  20. Pyrolysis of hardwoods residues: on kinetics and chars characterization

    Energy Technology Data Exchange (ETDEWEB)

    Della Rocca, P.A.; Cerrella, E.G.; Bonelli, P.R.; Cukierman, A.L. [Universidad de Buenos Aires (Argentina). PINMATE, Departamento de Industrias

    1999-11-01

    Evolution of chemical and textural-morphological features characterizing two native Argentinian hardwood species (Aspidosperma Quebracho Blanco Schlecht and Aspidosperma Australe), subjected to pyrolysis at different operating conditions, is analysed by several techniques. Surface areas of raw materials and pyrolysed samples are evaluated from physical adsorption measurements employing N{sub 2} at 77 K and CO{sub 2} at 298 K. The samples are also examined by optical and scanning electronic microscopy. Results point to significant feature changes, which are, in general, strongly affected by pyrolysis conditions, particularly temperature. Furthermore, kinetic measurements of wood pyrolysis are performed by non-isothermal thermogravimetric analysis, from ambient temperature up to 1123 K. A deactivation model reported in the literature, which predicts an increase of activation energy with reaction extent, successfully describes kinetic data for both species over the whole range of degradation temperatures. (author)

  1. Singularities of pluri-theta divisors in Char $p>0$

    CERN Document Server

    Hacon, Christopher D

    2011-01-01

    We show that if $(X,\\Theta)$ is a PPAV over an algebraically closed field of characteristic $p>0$ and $D\\in |m\\Theta|$, then $(X,\\frac 1 m D)$ is a limit of strongly $F$-regular pairs and in particular ${\\rm mult}_x(D)\\leq m\\cdot \\dim X$ for any $x\\in X$.

  2. Effects of Nonequilibrium Chemistry and Darcy-Forchheimer Pyrolysis Flow for Charring Ablator

    Science.gov (United States)

    Chen, Yih-Kanq; Milos, Frank S.

    2013-01-01

    The fully implicit ablation and thermal response code simulates pyrolysis and ablation of thermal protection materials and systems. The governing equations, which include energy conservation, a three-component decomposition model, and a surface energy balance, are solved with a moving grid.This work describes new modeling capabilities that are added to a special version of code. These capabilities include a time-dependent pyrolysis gas flow momentum equation with Darcy-Forchheimer terms and pyrolysis gas species conservation equations with finite rate homogeneous chemical reactions. The total energy conservation equation is also enhanced for consistency with these new additions. Two groups of parametric studies of the phenolic impregnated carbon ablator are performed. In the first group, an Orion flight environment for a proposed lunar-return trajectory is considered. In the second group, various test conditions for arcjet models are examined. The central focus of these parametric studies is to understand the effect of pyrolysis gas momentum transfer on material in-depth thermal responses with finite-rate, equilibrium, or frozen homogeneous gas chemistry. Results indicate that the presence of chemical nonequilibrium pyrolysis gas flow does not significantly alter the in-depth thermal response performance predicted using the chemical equilibrium gas model.

  3. Pyrite thermochemistry, ash agglomeration, and char fragmentation during pulverized coal combustion. Final technical report

    Energy Technology Data Exchange (ETDEWEB)

    Akan-Etuk, A.; Diaz, R.; Niksa, S.

    1991-10-01

    The objective of the present work is to introduce an experimental program that will eventually lead to time-resolved iron ash composition over the technological operating domain. The preceding literature survey suggests two important stipulations on any such experimental program. The first stipulation is that good control must be established over the operating conditions, to accurately quantify their effects. The other is that data must be obtained rapidly, to thoroughly cover the important operating domain. This work presents a series of studies that has characterized the desulfurization of pyrite during the early stages of combustion. An experimental system was established and used to monitor the effects of oxygen, temperature, and residence time on the evolution of condensed phase products of the combustion of pure pyrite. (VC)

  4. Pyrite thermochemistry, ash agglomeration, and char fragmentation during pulverized coal combustion

    Energy Technology Data Exchange (ETDEWEB)

    Akan-Etuk, A.; Diaz, R.; Niksa, S.

    1991-10-01

    The objective of the present work is to introduce an experimental program that will eventually lead to time-resolved iron ash composition over the technological operating domain. The preceding literature survey suggests two important stipulations on any such experimental program. The first stipulation is that good control must be established over the operating conditions, to accurately quantify their effects. The other is that data must be obtained rapidly, to thoroughly cover the important operating domain. This work presents a series of studies that has characterized the desulfurization of pyrite during the early stages of combustion. An experimental system was established and used to monitor the effects of oxygen, temperature, and residence time on the evolution of condensed phase products of the combustion of pure pyrite. (VC)

  5. Plastic resource polymorphism: effects of resource availability on Arctic char ( Salvelinus alpinus ) morphology

    NARCIS (Netherlands)

    J. Andersson; P. Bystrom; L. Persson; A.M. de Roos

    2005-01-01

    6. Abstract (optional): Resource polymorphism has been suggested to be a platform for speciation. In some cases resource polymorphism depends on phenotypic plasticity but in other cases on genetic differences between morphotypes, which in turn has been suggested to be the ongoing development of a sp

  6. Evaluation of the toxicity of char residues produced in the co-pyrolysis of different wastes

    OpenAIRE

    Bernardo, Maria; Lapa, N.; Gonçalves, Margarida; Barbosa, Rui; Mendes, Benilde; Pinto, Filomena

    2009-01-01

    The high amounts of solid waste produced in industrial installations and in urban centers is a complex problem of today's society. The traditional strategies for solid waste transformation and disposal include and filling or incineration. Other approaches are being exploited namely waste selective collection and recycling on the energetic valorization of solid wastes through pyrolysis. In the pyrolytic process, the wastes are converted into a gaseous and liquid phase that can be used in energ...

  7. Existence of flips and minimal models for 3-folds in char p

    OpenAIRE

    Birkar, Caucher

    2013-01-01

    We will prove the following results for $3$-fold pairs $(X,B)$ over an algebraically closed field $k$ of characteristic $p>5$: log flips exist for $\\Q$-factorial dlt pairs $(X,B)$; log minimal models exist for projective klt pairs $(X,B)$ with pseudo-effective $K_X+B$; the log canonical ring $R(K_X+B)$ is finitely generated for projective klt pairs $(X,B)$ when $K_X+B$ is a big $\\Q$-divisor; semi-ampleness holds for a nef and big $\\Q$-divisor $D$ if $D-(K_X+B)$ is nef and big and $(X,B)$ is p...

  8. Biomass gasification: the understanding of sulfur, tar, and char reaction in fluidized bed gasifiers

    OpenAIRE

    Meng, X.

    2012-01-01

    As one of the currently available thermo-chemical conversion technologies, biomass gasification has received considerable interest since it increases options for combining with various power generation systems. The product gas or syngas produced from biomass gasification is environmental friendly alternatives to conventional petrochemical fuels for the production of electricity, hydrogen, synthetic transportation biofuels and other chemicals. The product gas normally contains the major compon...

  9. Modeling the combined impact of moisture and char shrinkage on the pyrolysis of a biomass particle

    Energy Technology Data Exchange (ETDEWEB)

    Kenneth M. Bryden; Mathew J. Hagge [Iowa State University, Ames, IA (USA). Department of Mechanical Engineering

    2003-09-01

    A detailed computational model of pyrolysis of a moist, shrinking biomass particle is presented. This model is used to examine the effect of varying the moisture content for a single shrinking biomass particle subjected to a constant external temperature. Particle half-thicknesses ranging from 5{mu} m to 2 cm, temperatures from 800 to 2000 K, moisture contents from 0 to 30% (dry basis), and shrinkage factors from 1.0 to 0.4 are examined. The impact of moisture content and shrinkage was found to be a function of pyrolysis regime. In general, coupling between moisture content and shrinkage was found to result in longer pyrolysis times than if they were considered separately. Additionally, coupling between moisture content and shrinkage increased tar yield and decreased light hydrocarbon yield compared to considering moisture and shrinkage separately. 29 refs., 10 figs., 4 tabs.

  10. Diffusion of gases in coals and chars: Final report, September 15, 1985--September 14, 1988

    Energy Technology Data Exchange (ETDEWEB)

    Smith, D.M.

    1988-01-01

    Eight PSOC coals representing a wide range of rank and geographic origin have been subjected to a wide range of pore structure analysis methods as well as gas diffusion measurements. Pore structure analysis techniques employed included carbon dioxide and nitrogen adsorption, helium pycnometry, mercury porosimetry, and low-field NMR spin-lattice relaxation measurements. In principle, NMR pore structure analysis avoids many of the problems associated with conventional pore structure methods such as pore structure changes during drying, sample compression, network/percolation effects, pore shape assumptions, and a limited pore size range. Spin-lattice relaxation measurements were conducted at a proton frequency of 20 MHz and 303 K using water contained in the coal pores. Pore size distributions were obtained via deconvolution of the NMR relaxation measurements using the method of regularization and application of the ''two fraction-fast exchange'' model of pore fluid behavior. A qualitative comparison of the NMR pore size distributions and surface areas (CO/sub 2//N/sub 2/) yielded good agreement. Monodisperse and bidisperse pore size distributions were noted with pore volume in the size range of <0.5 nm to 0.5 ..mu..m. Effective diffusivities of methane and nitrogen were measured at 303 K and ambient pressure using a pulse tracer analysis method. 37 refs., 14 figs., 5 tabs.

  11. On the preparation and characterization of chars and activated carbons from orange skin

    Energy Technology Data Exchange (ETDEWEB)

    Rosas, J.M.; Bedia, J.; Rodriguez-Mirasol, J.; Cordero, T. [Chemical Engineering Department, School of Industrial Engineering, Campus de Teatinos s/n, 29071, University of Malaga (Spain)

    2010-10-15

    Activated carbons were obtained by carbonization of orange skin waste and partial gasification with CO{sub 2}. The orange skin contains a significant amount of inorganic matter mainly potassium, calcium and phosphorus. CO{sub 2} gasification is catalyzed by potassium and calcium, resulting in carbons with a microporous structure. Thermal treatment up to 900 C applied to orange skin-derived activated carbons yields carbons with a highly developed porous structure, and a significant contribution of mesopores, due to the activation effect of potassium compounds. This porous structure is initially blocked by the inorganic matter that is removed by a subsequent acid wash, opening the porous structure of the final carbon; an activated carbon with a very wide porous structure and a specific surface area of around 1200 m{sup 2}/g was obtained. The activated carbon with high potassium content shows relatively high NO adsorption capacities in the presence of oxygen at 120 C, probably due to the catalytic effect of potassium on the oxidation of NO. The breakthrough times of the NO adsorption in the presence of oxygen at 120 C were predicted by the Bohart and Adams model with a relevant agreement between the calculated and the experimental times. (author)

  12. Animal Bones Char Solubilization by Gel-Entrapped Yarrowia lipolytica on Glycerol-Based Media

    Directory of Open Access Journals (Sweden)

    Maria Vassileva

    2012-01-01

    Full Text Available Citric acid was produced with free and k-carrageenan-entrapped cells of the yeast Yarrowia lipolytica in single and repeated batch-shake-flask fermentations on glycerol-based media. Simultaneous solubilization of hydroxyapatite of animal bone origin (HABO was tested in all experiments. The highest citric acid production by free yeast cells of 20.4 g/L and 18.7 g/L was reached after 96 h of fermentation in the absence and presence of 3 g/L HABO, respectively. The maximum values for the same parameter achieved by gel-entrapped cells in conditions of single batch and repeated-batch fermentation processes were 18.7 g/L and 28.1 g/L registered after 96 h and the 3d batch cycle, respectively. The highest citric acid productivity of 0.58 g L−1 h−1 was obtained with immobilized cells in repeated batch mode of fermentation when the added hydroxyapatite of 3 g/L was solubilized to 399 mg/L whereas the maximum efficiency of 89.0% was obtained with 1 g/L of HABO.

  13. Biomass char as an in-situ catalyst for tar removal in gasification systems

    NARCIS (Netherlands)

    Abu El-Rub, Ziad Yousef Kamel

    2008-01-01

    The contribution of biomass to the world’s energy supply is presently estimated to be around 10 to 14 %. The European Union set a firm target of cutting 20% of the EU’s greenhouse gas emissions by 2020 - the EU will be willing to put this goal up to 30% if the US, China and India make similar commit

  14. Geosmin causes off-flavours in artic char raised in recirculating aquaculture systems

    Science.gov (United States)

    The “earthy” and “muddy” off-flavour taste in pond-reared fish is due to the presence of geosmin and 2-methylisoborneol (MIB) in the flesh of the fish. Planktonic and benthic cyanobacteria and actinomycetes are known sources of MIB and geosmin. When these compounds are absorbed into the flesh of the...

  15. CO2 adsorption properties of char produced from brown coal impregnated with alcohol amine solutions.

    Science.gov (United States)

    Baran, Paweł; Zarębska, Katarzyna; Czuma, Natalia

    2016-07-01

    Carbon dioxide (CO2) emission reduction is critical to mitigating climate change. Power plants for heating and industry are significant sources of CO2 emissions. There is a need for identifying and developing new, efficient methods to reduce CO2 emissions. One of the methods used is flue gas purification by CO2 capture through adsorption. This study aimed to develop CO2 adsorbent out of modified brown coal impregnated with solutions of first-, second-, and third-order amines. Low-temperature nitrogen adsorption isotherms and CO2 isotherms were measured for the prepared samples. The results of experiments unexpectedly revealed that CO2 sorption capacity decreased after impregnation. Due to lack of strait trends in CO2 sorption capacity decrease, the results were closely analyzed to find the reason for the inconsistencies. It was revealed that different amines represent different affinities for CO2 and that the size and structure of impregnating factor has influence on the CO2 sorption capacity of impregnated material. The character of a support was also noticeable as well for impregnation results as for the affinity to CO2. The influence of amine concentration used was investigated along with the comparison on how the theoretical percentage of the impregnation on the support influenced the results. The reaction mechanism of tertiary amine was taken into consideration in connection to no presence of water vapor during the experiments. Key findings were described in the work and provide a strong basis for further studies on CO2 adsorption on amine-impregnated support. PMID:27317051

  16. Evaluation of Infrasound and Strobe Lights to Elicit Avoidance Behavior in Juvenile Salmon and Char.

    Energy Technology Data Exchange (ETDEWEB)

    Mueller, Robert, P.; Neitzel, Duane A.; Amidan, Brett G.

    1999-02-01

    Experimental tests were conducted using hatchery reared and wild juvenile chinook salmon Oncorhynchus tshawytscha, eastern brook trout Salvelinus fontinalis, and rainbow trout O. mykiss to determine specific behavior responses to infrasound (<20 Hz) and flashing strobe lights. Caged fish were acclimated in a static test tank and their behavior was recorded using low light cameras. Species specific behavior was characterized by measuring movements of the fish within the cage as well as observing startle and habituation responses. Wild chinook salmon (40-45 mm) and hatchery reared chinook salmon (45-50mm) exhibited avoidance responses when initially exposed to a 10 Hz volume displacement source. Rainbow and eastern brook trout (25-100 mm) did not respond with avoidance or other behaviors to infrasound. Habituation to the infrasound source was evident for chinook salmon during repeated exposures. Wild and hatchery chinook displayed a higher proportion of movement during the initial exposures to infrasound when the acclimation period in the test tank was 2-3 h as compared to a 12-15 h acclimation period. A flashing strobe light produced higher and more consistent movement rates in wild chinook (60% of the tests); hatchery reared chinook salmon (50%) and rainbow trout (80%). No measurable movement or other responses was observed for eastern brook trout. Little if any habituation was observed during repeated exposures to strobe lights. Results from this study indicate that consistent repeatable responses can be elicited from some fish using high intensity strobe lights under a controlled laboratory testing. The specific behaviors observed in these experiments might be used to predict how fish might react to low frequency sound and strobe lights in a screening facility. Because sub-yearling salmonids and resident species are susceptible from becoming entrained at water diversion structures we conducted tests in conjunction with our evaluation of juvenile fish screening facilities. This is the reason our tests focused on fry life stages.

  17. Influence of carbonization conditions on micro-pore structure of foundry formed coke produced with char

    Energy Technology Data Exchange (ETDEWEB)

    Jun Qiao; Jianjun Wu; Jingru Zu; Zhiyuan Gao; Guoli Zhou

    2009-07-01

    There are few studies on coke's micro-pore structure in recent years, however, micro-pore structure of foundry coke determines its macroscopically quality index and reactivity in cupola furnace. Effect of such factors on micro-pore structure were investigated under different carbonization conditions with certain ratio of raw materials and material forming process in this article as charging temperature (A); braised furnace time (B); heating rate of the first stage (C)and the second stage (D) and holding time of ultimate temperature (E). Research showed that charging temperature was the most influential factor on the coke porosity, pore volume, pore size and specific surface area. It is suggested that formation of plastic mass and releasing rate of volatile during carbonization period are two main factors on microstructure of foundry coke while charging temperature contributes most to the above factors. 6 refs., 4 figs., 9 tabs.

  18. Bitumen on Water: Charred Hay as a PFD (Petroleum Flotation Device)

    OpenAIRE

    Nusrat Jahan; Jason Fawcett; Thomas L. King; Alexander M. McPherson; Katherine N. Robertson; Ulrike Werner-Zwanziger; Clyburne, Jason A. C.

    2015-01-01

    Global demand for petroleum keeps increasing while traditional supplies decline. One alternative to the use of conventional crude oils is the utilization of Canadian bitumen. Raw bitumen is a dense, viscous, semi-liquid that is diluted with lighter crude oil to permit its transport through pipelines to terminals where it can then be shipped to global markets. When spilled, it naturally weathers to its original form and becomes dense enough to sink in aquatic systems. This severely limits oil ...

  19. Animal Bones Char Solubilization by Gel-Entrapped Yarrowia lipolytica on Glycerol-Based Media

    OpenAIRE

    Maria Vassileva; Bettina Eichler-Lobermann; Antonia Reyes; Nikolay Vassilev

    2012-01-01

    Citric acid was produced with free and k-carrageenan-entrapped cells of the yeast Yarrowia lipolytica in single and repeated batch-shake-flask fermentations on glycerol-based media. Simultaneous solubilization of hydroxyapatite of animal bone origin (HABO) was tested in all experiments. The highest citric acid production by free yeast cells of 20.4???g/L and 18.7???g/L was reached after 96???h of fermentation in the absence and presence of 3???g/L HABO, respectively. The maximum values for th...

  20. Evaluation of Infrasound and Strobe Lights for Eliciting Avoidance Behavior in Juvenile Salmon and Char

    Energy Technology Data Exchange (ETDEWEB)

    Mueller, Robert P.(BATTELLE (PACIFIC NW LAB)); Neitzel, Duane A.(BATTELLE (PACIFIC NW LAB)); Amidan, Brett G.(BATTELLE (PACIFIC NW LAB))

    2001-12-01

    Laboratory tests were conducted using juvenile chinook salmon Oncorhynchus tshawytscha, brook trout Salvelinus fontinalis, and rainbow trout O. mykiss to determine specific behavior responses to infrasound (< 20 Hz) and flashing strobe lights. The objective of these tests was to determine if juvenile salmonids could be deterred from entrainment at water diversion structures. Caged fish were acclimated in a static test tank and their behavior was recorded using low light cameras. Species-specific behavior was characterized by measuring movements of the fish within the cage and by observing startle and habituation responses. Wild chinook salmon (40-45 mm TL) and hatchery reared chinook salmon (45-50 mm TL) exhibited avoidance responses when initially exposed to a 10-Hz volume displacement source of infrasound. Rainbow and eastern brook trout (25-100 mm TL) did not respond with avoidance or other behaviors to infrasound. Evidence of habituation to the infrasound source was evident for chinook salmon during repeated exposures. Wild and hatchery chinook displayed a higher proportion of movement during the initial exposures to infrasound when the acclimation period in the test tank was 2-3 h as compared to a 12-15 h acclimation period. A flashing strobe light produced consistent movement in wild chinook salmon (60% of the tests), hatchery reared chinook salmon (50%), and rainbow trout (80%). No measurable responses were observed for brook trout. Results indicate that consistent, repeatable responses can be elicited from some fish using high-intensity strobe lights under a controlled laboratory testing. The species specific behaviors observed in these experiments might be used to predict how fish might react to low-frequency sound and strobe lights in a screening facility.

  1. Density-dependent interactions in an Arctic char - brown trout system: competition, predation, or both?

    NARCIS (Netherlands)

    L. Persson; P.A. Amundsen; A.M. de Roos; R. Knudsen; R. Primicerio; A. Klemetsen

    2013-01-01

    In the study of mechanisms structuring fish communities, mixed competition-predation interactions where large predators feed on prey fish versus those in which small predators compete with prey fish for a shared prey have been the focus of substantial research. We used a long-term data set from a sy

  2. Distribution of charred organic matter in the humic fractions of a fire affected xerochrept

    OpenAIRE

    Knicker, Heike; González-Vila, Francisco Javier; Polvillo, Oliva; González-Pérez, José Antonio; Almendros Martín, Gonzalo

    2003-01-01

    1 página. Póster presentado en la 2Sesion: Process understanding. Where does the carbon go?. Soil processes. Trabajo presentado a la referida conferencia, celebrada del 19-21 de marzo, 2003, en Lisboa.

  3. Feasibility of mercury removal from simulated flue gas by activated chars made from poultry manures

    Science.gov (United States)

    Increased emphasis on reduction of mercury emissions from coal fired electric power plants has resulted in environmental regulations that may in the future require application of activated carbons as mercury sorbents for mercury removal. At the same time, the quantity of poultry manure generated eac...

  4. Teleost reproduction: Aspects of Arctic char (Salvelinus alpinus) oocyte growth and maturation.

    OpenAIRE

    Berg, Håkan

    2003-01-01

    In all vertebrate species, reproduction is a hormonally controlled process, important for growth and maturation of gonads and germ cells. Production of functional germ cells is of outmost importance to secure the survival of a species. Fish comprises 50% of the known vertebrates and are found in aquatic habitats all over the world. Even though fish have evolved a wide variety of morphological and physiological characteristics, due to large differences in the living environment, the growth an ...

  5. Experimental and theoretical investigation on unburned coal char burnout in a pilot-scale rotary kiln

    Energy Technology Data Exchange (ETDEWEB)

    Federico Cangialosi; Francesco Di Canio; Gianluca Intini; Michele Notarnicola; Lorenzo Liberti; Giulio Belz; Pompilio Caramuscio [Technical University of Bari, Taranto (Italy). Department of Environmental Engineering and Sustainable Development

    2006-11-15

    Oxidation reactivity studies are imperative for improving carbon re-burn technologies and valuing the heat content of unburned carbon within coal combustion ashes. Non-isothermal, thermal gravimetric analysis (TGA) was used to examine the oxidation kinetics of unburned carbon in coal combustion fly ashes having different particle size distributions; TGA results were related to combustion efficiencies as measured in a bench-scale rotary kiln. The activation energy and pre-exponential factor were determined for the chemically-controlled reaction regime; the transition temperatures between chemically-controlled and partially diffusion-controlled combustion regimes were obtained for unburned carbon particles of different sizes. After the oxidation reaction rates were evaluated, the residence time distribution (RTD) of fly ashes in the rotary kiln were experimentally measured and the mean residence times related to process parameters, including the rotating velocity and kiln inclination. By comparing these results with an advective-dispersive model, the axial dispersion coefficient of fly ashes was determined. The reaction rates obtained by thermal analyses and the RTDs were used to predict combustion efficiencies within the kiln and oxidation conditions of unburned carbon using various processing options. 21 refs., 6 figs., 4 tabs.

  6. Charred olive stones: experimental and archaeological evidence for recognizing olive processing residues used as fuel

    NARCIS (Netherlands)

    Braadbaart, Freek; Marinova, E.; Sarpaki, A.

    2016-01-01

    After extracting oil from olives a residue is left usually referred to as the olive oil processing residue (OPR). This study explores the way in which ancient societies may have used OPR as fuel for fires to generate heat and the various issues that are related to the residues of this fuel. After dr

  7. Response Modeling of Lightweight Charring Ablators and Thermal Radiation Testing Results

    Science.gov (United States)

    Congdon, William M.; Curry, Donald M.; Rarick, Douglas A.; Collins, Timothy J.

    2003-01-01

    Under NASA's In-Space Propulsion/Aerocapture Program, ARA conducted arc-jet and thermal-radiation ablation test series in 2003 for advanced development, characterization, and response modeling of SRAM-20, SRAM-17, SRAM-14, and PhenCarb-20 ablators. Testing was focused on the future Titan Explorer mission. Convective heating rates (CW) were as high as 153 W/sq cm in the IHF and radiation rates were 100 W/sq cm in the Solar Tower Facility. The ablators showed good performance in the radiation environment without spallation, which was initially a concern, but they also showed higher in-depth temperatures when compared to analytical predictions based on arc-jet thermal-ablation response models. More testing in 2003 is planned in both of these facility to generate a sufficient data base for Titan TPS engineering.

  8. Spontaneous ignition of wood, char and RDF in a lab scale packed bed

    NARCIS (Netherlands)

    Blijderveen, M. van; Gucho, E.M.; Bramer, E.A.; Brem, G.

    2010-01-01

    Many municipal waste combustors use preheated primary air in the first zone to dry the waste. In most cases the preheat temperature does not exceed 140 °C. In previous experiments it is found that at temperatures around 200 °C, in some circumstances, self- or spontaneous ignition can be achieved. Us

  9. SiteChar. Characterisation of European CO2 storage. Deliverable D8.2. Trust building and raising public awareness

    Energy Technology Data Exchange (ETDEWEB)

    Brunsting, S.; Pol, M.; Mastop, E.A. [ECN Policy Studies, Energy research Centre of the Netherlands ECN, Amsterdam (Netherlands); Kaiser, M.; Zimmer, R. [Unabhaengiges Institut fuer Umweltfragen UfU, Berlin (Germany); Shackley, S.; Mabon, L.; Howell, R. [Scottish Carbon Capture and Storage SCCS, Edinburg, Scotland (United Kingdom)

    2012-08-15

    At local level, public support has proven crucial to the implementation of CO2 capture and storage (CCS) demonstration projects. Whereas no method exists to guarantee public acceptability of any project, a constructive stakeholder and community engagement process does increase the likelihood thereof. This deliverable is a follow-up to deliverable D8.1 'Social site characterisation'. Social site characterisation can be used as an instrument to explore, plan and evaluate a process of active and constructive local stakeholder and citizen engagement in a prospective CCS project as a parallel activity to technical site characterisation. It serves as an analytical tool to describe the local social circumstances in the area and to design and evaluate stakeholder and community engagement efforts with the aims of building trust and raising public awareness. Using results from the social site characterisation of the area, the present deliverable focuses on the second purpose. It presents results from public engagement activities designed to raise public awareness and inform public opinion of a prospective CCS site in Poland (onshore) and the UK (offshore): focus conferences. Furthermore, by initiating an enhanced cooperation in planning of new storage sites between project developers, authorities and the local public, focus conferences aim to serve as a 'hinge' between social site characterisation as a research effort and application to real-life project settings. The focus conferences are part of a range of public engagement activities including the setup of public information websites on generic and site-specific CCS, information meetings. A second survey eventually shall evaluate the results of the public engagement activities. The aim of the focus conferences was to raise public awareness and assist public opinion forming processes of a prospective CCS site in Poland (onshore) and the UK (offshore). At the same time, it aimed to present and test a format in which project developers, authorities, and the local public could enhance their cooperation in project planning. To this end, a group of 11-16 participants recruited from the local public gathered on two weekends to be informed about CCS technology, to discuss their perceptions of the rewards and risks of CCS technology, and to state their conditions for a socially acceptable implementation of CCS projects. Experts from research, politics, industry and NGOs were invited to participate in both weekends, during which they gave presentations and answered questions from the participants. This process resulted in a positioning paper written by the participants representing a statement on CCS technology from their perspective.

  10. Effects of Non-Equilibrium Chemistry and Darcy-Forchheimer Flow of Pyrolysis Gas for a Charring Ablator

    Science.gov (United States)

    Chen, Yih-Kanq; Milos, Frank S.

    2011-01-01

    The Fully Implicit Ablation and Thermal Response code, FIAT, simulates pyrolysis and ablation of thermal protection materials and systems. The governing equations, which include energy conservation, a three-component decomposition model, and a surface energy balance, are solved with a moving grid. This work describes new modeling capabilities that are added to a special version of FIAT. These capabilities include a time-dependent pyrolysis gas flow momentum equation with Darcy-Forchheimer terms and pyrolysis gas species conservation equations with finite-rate homogeneous chemical reactions. The total energy conservation equation is also enhanced for consistency with these new additions. Parametric studies are performed using this enhanced version of FIAT. Two groups of analyses of Phenolic Impregnated Carbon Ablator (PICA) are presented. In the first group, an Orion flight environment for a proposed Lunar-return trajectory is considered. In the second group, various test conditions for arcjet models are examined. The central focus of these parametric studies is to understand the effect of pyrolysis gas momentum transfer on PICA material in-depth thermal responses with finite-rate, equilibrium, or frozen homogeneous gas chemistry. Results are presented, discussed, and compared with those predicted by the baseline PICA/FIAT ablation and thermal response model developed by the Orion Thermal Protection System Advanced Development Project.

  11. Aquaculture and the Environment. Life Cycle Assessment on Icelandic Arctic char fed with three different feed types

    OpenAIRE

    Birgir Örn Smárason 1984

    2013-01-01

    With ever growing consumption the world tries to supply food for a population exceeding 7 billion. Aquaculture has been heralded for its potential to meet this huge increase in food demand and is therefore a large contributor to feed the world. It continues to be the fastest growing animal food production sector, accounting for 45.6% of the world‘s fish consumption in 2011. However, according to WWF one-third of global wild-caught fish is processed into fishmeal and fish oil used in large qua...

  12. Sustainable production of bioenergy and bio-char from the straw of high biomass soybean lines via fast pyrolysis

    Science.gov (United States)

    The straws of two high-biomass soybean lines developed at ARS for bioenergy were subjected to thermochemical conversion by fast pyrolysis. The objective was to evaluate the potential use of the straw for the production of liquid fuel intermediates that can be burned “as is” and/or potentially upgra...

  13. Iranian clonal population of Salmonella enterica serovar Enteritidis, char- acterized by multi-locus sequence typing (MLST method

    Directory of Open Access Journals (Sweden)

    Rainak Ghaderi

    2015-12-01

    Full Text Available Background and Objectives: Some 2 million tons of chicken meat is produced by Iran per annum, positioning Iran among the top producers in the region. This study aimed to evaluate the molecular epidemiology and genetic characteristics of Sal- monella enterica Enteritidis in Iran.Materials and Methods: A representative selection of isolates (n=76, initially genotyped by a 7-locus MLVA typing sys- tem, was examined by the standard MLST genotyping.Results and Conclusion: All the MLVA typed isolates, classified into six types, were gathered under a single ST11 MLST type. This is an intriguing observation as much more genome heterogeneity was expected considering the extent of diversity in the host and geography origin of the examined isolates. ST11, on the other hand is not exclusively found in Iran as it is reported also from Brazil, Denmark, Japan and the United States. In explanation of these observations, ST11 might stand for a single probably ancestral clone of Salmonella enterica Enteritidis successfully scattered in all these geographically diverse countries. Further global investigation covering more isolates and methods like whole genome sequencing would be advisable. Keywords: Salmonella enterica Enteritidis, MLST, MLVA, Genetic diversity

  14. Nondébridement of laser char after two carbon dioxide laser passes results in faster reepithelialization

    DEFF Research Database (Denmark)

    Collawn, Sherry S; Woods, Anne; Couchman, John R

    2003-01-01

    Skin repair following laser injury can be accelerated by using techniques that promote rapid reepithelialization. In this article, the benefit of intraoperative nondébridement of laser debris after two laser passes is discussed. After carbon dioxide laser resurfacing of the face, skin specimens...... were examined using indirect immunofluorescence with antibodies to specific epidermal and basement membrane proteins. Biopsy specimens obtained immediately after resurfacing showed a greater injury to epidermal and basement membrane proteins when skin was wiped with saline-soaked gauze after laser...... of resurfacing along with the use of postoperative occlusive dressings led to the rapid reestablishment of a multilayered epidermis only 2 days after resurfacing. Nondébridement along with occlusive dressings results in rapid reepithelialization of the skin after two carbon dioxide laser passes for skin...

  15. Charring of wood with thermal radiation, 3: Effects of surface type on combustion and prediction of heat release rate

    International Nuclear Information System (INIS)

    The radial, tangential, and cross sections of four wood species were tested in a cone calorimeter to investigate the effects of surface types on combustion and to predict the heat release rates and fire endurances. The ignition time was delayed in proportion to the increase of density. The ignition times of the cross-sections were longer than those of the other sections. In the case of the same species, although apparent density p and specific heat c were the same, thermal conductivity k of the longitudinal direction of wood was larger than that in the transverse direction. Consequently, these phenomena are explained by the equation where the ignition time is in proportion to k, p, and c, The heat release rate of wood under a constant radiant heat flux is divided into three stages, and Stages I and III can be explained by using the model of unsteady-state thermal conduction in a semi infinite solid and in an infinite flat plate, respectively. In Stage II, the density, the presence of vessel elements, and the occurrence of cracks cause the differences of the heat release rates among species and surface types. The average heat release rate and the fire endurance time could be predicted easily by using the density, the rate of vessel elements, the thickness of the specimen, and the effective heat of combustion. (author)

  16. Toward a "molecular thermometer" to estimate the charring temperature of wildland charcoals derived from different biomass sources.

    Science.gov (United States)

    Schneider, Maximilian P W; Pyle, Lacey A; Clark, Kenneth L; Hockaday, William C; Masiello, Caroline A; Schmidt, Michael W I

    2013-10-15

    The maximum temperature experienced by biomass during combustion has a strong effect on chemical properties of the resulting charcoal, such as sorption capacity (water and nonpolar materials) and microbial degradability. However, information about the formation temperature of natural charcoal can be difficult to obtain in ecosystems that are not instrumented prior to fires. Benzene polycarboxylic acids (BPCA) are molecular markers specific for pyrogenic carbon (PyC) which can provide information on the degree of aromatic condensation in charcoals. Here we apply the BPCA molecular marker method to a set of 10 charcoals produced during an experimental fire in a Pitch pine-scrub oak forest from litter and bark of pitch pine and inkberry plants in the Pinelands National Reserve in New Jersey, USA. We deployed temperature-sensitive crayons throughout the burn site, which recorded the maximum air temperature and made comparisons to the degree of thermal alteration recorded by BPCA molecular markers. Our results show an increase of the degree of aromatic condensation with monitored temperatures for bark biomass, while for needles no clear trend could be observed. For leaf-derived charcoals at increasing monitored fire temperatures, decreasing degree of aromatic condensation was obtained. This suggests that molecular markers can be used to roughly estimate the maximum fire temperatures experienced by bark and wood materials, but not based on leaf- and needle-derived materials. Possible applications include verifying declared pyrolysis temperatures of biochars and evaluating ecosystem fire temperature postburn. PMID:24040784

  17. Clean, premium-quality chars: Demineralized and carbon enriched. Quarterly report, December 1, 1991--February 29, 1992

    Energy Technology Data Exchange (ETDEWEB)

    Smith, G.V. [Southern Illinois Univ., Carbondale, IL (United States)

    1992-08-01

    The interaction of methane, methane/oxygen, helium, and hydrogen with IBC-102 coal samples ({le} 2mg) has been investigated in a thermogravimetric reactor at 20{degrees}C--650{degrees}C. The results show that the reactive gases are converting some of the mineral matter of the coal into catalysts through chemical reactions (reduction or oxidation). Also, these gases (except He) dissolve in the softened coal. Added clays (kaolinite and Ca-montmorillonite) increase the reactivity of the coal. This higher reactivity may be attributed to the fact that clays may serve as catalysts for methane activation, may prevent the coal agglomeration, and/or may increase the number of active sites for the reaction by modification of the geometric structure of the coal surface. Differential Scanning Calorimetry (DSC) experiments show that clean coal (no mineral matter) devolatilizes at a lower temperature than raw coal. Also, the preoxidation at 150{degrees}C for 50 minutes results in a 13{degrees} lowering of the devolatilization temperature. ISDR-FTIR experiments suggest that phenol groups of the coal play an important role in the cross-linkage of the coal structure when thermally treated.

  18. The molecular structure of selected South African coal-chars to elucidate fundamental principles of coal gasification / Mokone Joseph Roberts

    OpenAIRE

    Roberts, Mokone Joseph

    2015-01-01

    Advances in the knowledge of chemical structure of coal and development of high performance computational techniques led to more than hundred and thirty four proposed molecular level representations (models) of coal between 1942 and 2010. These models were virtually on the carboniferous coals from the northern hemisphere. There are only two molecular models based on the inertinite- and vitrinite-rich coals from the southern hemisphere. The current investigation is based on the ...

  19. Composition and reactivity of morphologically distinct charred materials left after slash-and-burn practices in agricultural tropical soils

    OpenAIRE

    Rumpel, C.; Gonzalez Perez, J. A.; Bardoux, G.; Largeau, C.; Gonzalez Vila, F. J.; Valentin, Christian

    2007-01-01

    The composition of black carbon (BC) was studied up to now using laboratory experiments, which often fail to reproduce conditions occurring in natural fires. We sampled plant material and two BC fractions produced during slash and burn agriculture from two adjacent sites. A coarse fraction (CF), most probably derived from twigs and stems, was differentiated from lighter, fluffy fine material (FF). The samples were analysed for elemental and isotopic composition and their reactivity using acid...

  20. Diffusion of gases in coals and chars. Technical progress report: quarterly report No. 1, September 15-December 14, 1985

    Energy Technology Data Exchange (ETDEWEB)

    Smith, D.M.

    1986-01-01

    Several questions exist concerning the measurement of carbon dioxide surface areas for coal. The appropriate temperature and coal particle size need to be identified for CO/sub 2/ adsorption measurements using our Quantasorb ''flow type'' surface area analyzer. Preliminary CO/sub 2/ adsorption experiments have been conducted using a PSOC-26 coal sample. Measurements have been made at both 196 K and 273 K for three different particle sizes. The results of these measurements are presented in Table 1. The small effect of particle size on surface area at high temperature 273 K, indicates that our measurements are essentially independent of diffusional resistance. The small differences in surface area which we note as the particle size is decreased may be a function of opening closed pores which are not normally accessable to CO/sub 2/, the creation of more surface area during the size reduction process and/or very small diffusional resistance effects. In comparison to the 273 K results, our measurements at 196 K clearly indicate that the uptake of CO/sub 2/ is controlled by diffusion. Therefore, all subsequent CO/sub 2/ surface area determinations during this project will be conducted at 273 K using 325 mesh particles. In order to demonstrate the suitability of pore size analysis via NMR measurements, preliminary experimental work has been conducted using porous solids with well-defined pore size and pore shape. 2 refs., 1 tab.

  1. Evaluating energy efficiency and emissions of charred biomass used as a fuel for household cooking in rural Kenya

    OpenAIRE

    Achour, Nemer

    2015-01-01

    In sub-Saharan Africa a large share of the energy use utilize biomass as a fuel. In some countries more than 90 percent of the energy use is biomass. This energy is primarily used for cooking, heating and drying. Cooking food on an open fire or using a traditional stove will combust the firewood inefficiently and leads to pollution in the form of particulate matter, carbon monoxide and other hazardous pollutants. Indoor pollution has serious health effects and especially women and children ar...

  2. Distribution of Po-210 and Pb-210 in Arctic Char (Salvelinus alpinus) from an Arctic freshwater lake

    International Nuclear Information System (INIS)

    There is little information available with regard to the accumulation of Po-210 and Pb-210 by freshwater fish in natural freshwater systems despite the potential for relevant ingestion doses to man. This is maybe of particular pertinence for certain population groups where freshwater fish are an important dietary food item. Equally, it is important to understand the body distributions of these naturally occurring radionuclides to quantify the resulting doses to different tissues and organs of freshwater fish. With regard to the latter, it is important to consider not only the doses arising from bio-accumulated Po-210 and Pb-210 in various body compartments but additionally the internal dose from unabsorbed Po-210 and Pb-210 in the digestive tract. In this study, activity concentrations of Po-210 and Pb-210 were determined in muscle and various internal organs of Arctic Charr (Salvelinus alpinus) sampled from a lake in the Norwegian Arctic (69 deg. 4' N, 19 deg. 20' E). Observed activity concentrations of Po-210 and Pb-210 in different tissues will be discussed in relation to physiological parameters and ambient lake water activity concentrations. Results from this study will be compared to two similar studies conducted in freshwater systems where elevated activity concentrations of these radionuclides have been observed. Ingestion dose rates to man and effective absorbed dose rates to different tissues and organs of Arctic Charr from Po-210 and Pb-210 will be derived and compared to those from observed activity concentrations of the anthropogenic radionuclide Cs-137. (authors)

  3. Distribution of Po-210 and Pb-210 in Arctic Char (Salvelinus alpinus) from an Arctic freshwater lake

    Energy Technology Data Exchange (ETDEWEB)

    Gwynn, J.P.; Rudolfsen, G. [Norwegian Radiation Protection Authority, The Fram Centre, Tromsoe (Norway)

    2014-07-01

    There is little information available with regard to the accumulation of Po-210 and Pb-210 by freshwater fish in natural freshwater systems despite the potential for relevant ingestion doses to man. This is maybe of particular pertinence for certain population groups where freshwater fish are an important dietary food item. Equally, it is important to understand the body distributions of these naturally occurring radionuclides to quantify the resulting doses to different tissues and organs of freshwater fish. With regard to the latter, it is important to consider not only the doses arising from bio-accumulated Po-210 and Pb-210 in various body compartments but additionally the internal dose from unabsorbed Po-210 and Pb-210 in the digestive tract. In this study, activity concentrations of Po-210 and Pb-210 were determined in muscle and various internal organs of Arctic Charr (Salvelinus alpinus) sampled from a lake in the Norwegian Arctic (69 deg. 4' N, 19 deg. 20' E). Observed activity concentrations of Po-210 and Pb-210 in different tissues will be discussed in relation to physiological parameters and ambient lake water activity concentrations. Results from this study will be compared to two similar studies conducted in freshwater systems where elevated activity concentrations of these radionuclides have been observed. Ingestion dose rates to man and effective absorbed dose rates to different tissues and organs of Arctic Charr from Po-210 and Pb-210 will be derived and compared to those from observed activity concentrations of the anthropogenic radionuclide Cs-137. (authors)

  4. The formation of ammonia in air-blown gasification: does char-derived NO act as a precursor?

    Energy Technology Data Exchange (ETDEWEB)

    O. Amure; S. Hanson; M. Cloke; J.W. Patrick [University of Nottingham, Nottingham (United Kingdom). SChEME

    2003-10-01

    Air-blown gasification of coal has received considerable attention worldwide and especially in the UK in conjunction with the Air-Blown Gasification Cycle, an integrated combined cycle which has been developed in recent decades. The cycle has the potential to produce electricity at higher efficiencies and lower emissions than conventional pf plants. However, the formation of ammonia in the gasifier has been identified as a potential problem, as it would contribute to NOx emissions. The formation of ammonia has been studied in a laboratory-scale rig designed and constructed specifically for that purpose. The reactor was a fluidised bed of the spouted bed variety. NH{sub 3}, NO and HCN levels could be monitored at different bed heights to trace their formation and conversion. Four coals were gasified at 1000{sup o}C and 0.2 MPa. It was found that the bulk of the NH{sub 3} was formed in the spout and the NH{sub 3} concentration increased progressively with reactor height. Formation of NO was relatively minor and, although both NO and HCN may act as precursors for NH{sub 3} formation in the devolatilisation/partial combustion zone, no evidence was found to suggest they make a significant contribution to any subsequent increase in NH{sub 3} emissions. 12 refs., 4 figs., 2 tabs.

  5. Etude comparative relative à l’efficacité énergétique de deux appartements situés à Béchar, Algérie

    OpenAIRE

    BENOUDJAFER, I.; Ghomari, F.; Mokhtari, A.

    2012-01-01

    The aim of this paper is the Comparative Study on Energy Efficiency of two apartments which is located in Bechar (Algeria). In this regard, simulations were performed using the software simulation of thermal behavior in dynamic ‘TRNSYS 16’ with the numerical model type 56. This project is the introduction of insulating materials in buildings to improve thermal comfort and reduce energy consumption. Various solutions have been proposed or variants, which can make a relevant choice...

  6. Discussion of and reply to ``The retrofit of the MWC ROTEB in Rotterdam, Holland with a modern flue gas cleaning system including an activated char adsorption unit``

    Energy Technology Data Exchange (ETDEWEB)

    Niessen, W.R. [Camp Dresser and McKee Inc., Cambridge, MA (United States); Hasselriis, F. [Hasselriis (Floyd), Forest Hills, NY (United States); Hartenstein, H.U. [Steinmueller GmbH, Gummersbach (Germany)

    1995-11-01

    The authors had several questions concerning Hans-Ulrich Hartenstein`s pollution control system for a municipal solid waste combustion plant. In figure 4, parameter {micro} was held at a value of 0.8, yet the parameter was not identified. Also, the vertical scale on Figure 4 is missing. Further, which of the heavy metals is the worst? How much is too much? What is the cost of the facility? If Mr. Hartenstein had the opportunity to build this plant from the ground up, (a) Would he select this location? and (b) Would it have to be such a complicated plant? What simplifications could be made if he had a chance to build a new facility, while still achieving almost total emission control? What would Mr. Hartenstein suggest if salt water could not be discharged to the sea? This article also contains the original author`s reply to the comments and questions.

  7. Silicon drift-chamber prototype for the upgrade of the UA6 experiment at the CERN p /bar char/p collider

    International Nuclear Information System (INIS)

    A large-area (≅ 4 x 4 cm2) silicon drift chamber has been designed and constructed in order to investigate its possible use in the UA6 experiment. The drift chamber will supply unambiguously (x,y) space points on each track; each arm of the UA6 spectrometer will be provided with two layers of drift detectors. 12 refs., 4 figs

  8. Development of a high-performance coal-fired power generating system with pyrolysis gas and char-fired high temperature furnace (HITAF). Volume 1, Final report

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-02-01

    A major objective of the coal-fired high performance power systems (HIPPS) program is to achieve significant increases in the thermodynamic efficiency of coal use for electric power generation. Through increased efficiency, all airborne emissions can be decreased, including emissions of carbon dioxide. High Performance power systems as defined for this program are coal-fired, high efficiency systems where the combustion products from coal do not contact the gas turbine. Typically, this type of a system will involve some indirect heating of gas turbine inlet air and then topping combustion with a cleaner fuel. The topping combustion fuel can be natural gas or another relatively clean fuel. Fuel gas derived from coal is an acceptable fuel for the topping combustion. The ultimate goal for HIPPS is to, have a system that has 95 percent of its heat input from coal. Interim systems that have at least 65 percent heat input from coal are acceptable, but these systems are required to have a clear development path to a system that is 95 percent coal-fired. A three phase program has been planned for the development of HIPPS. Phase 1, reported herein, includes the development of a conceptual design for a commercial plant. Technical and economic feasibility have been analysed for this plant. Preliminary R&D on some aspects of the system were also done in Phase 1, and a Research, Development and Test plan was developed for Phase 2. Work in Phase 2 include s the testing and analysis that is required to develop the technology base for a prototype plant. This work includes pilot plant testing at a scale of around 50 MMBtu/hr heat input. The culmination of the Phase 2 effort will be a site-specific design and test plan for a prototype plant. Phase 3 is the construction and testing of this plant.

  9. Biochemical stability of organic matter in soils amended with organic slow N-release fertilizer derived from charred plant residues and ammonoxidized lignin

    OpenAIRE

    Knicker, Heike; Rosa Arranz, José M. de la; López Martín, María; Clemente Barragán, Reyes; Liebner, F.

    2013-01-01

    Comunicación oral presentada en la Sesión: SSS8.6/CL2.9: Biochar and organic waste in soils: global warming mitigation and SOM quality (co-organized).-- Congreso celebrado del 7-12 de abril 2013, Viena, Austria.

  10. CHAR ACTERIZA T ION OF THR EE BENZO A TE DEG RADING ANOX YGENIC PH OTOSYNTHETIC BA CTERI A ISO LA TED F RO M THE ENVIRONMENT

    Directory of Open Access Journals (Sweden)

    DWI SURYANTO

    2001-01-01

    Full Text Available Three anoxygenic photosyn thetic bacter ia, DS-1, DS-4 and Cas-13, have been exam in ated for their morphological and physiolog ical propert ies. All s trains were rod-sh ape ce lls with a swollen terminal end, Gram nega tive , motile, non-hal ophilic, non-alkal ophilic a n d non- acid ophilic , a nd capable of utilizing benzoate aerobically and photo-anaerobically. Sequ ence analysis of part of 16S rRNA genes showed that DS-1 and Cas- 13 we re cl osel y relate d to Rhodopseudomonas palustris Stra in 7 w ith a simila ri ty of 97%, where a s DS-4 ma y not be c losel y rela te d t o the former t wo str ai ns wit h a si milarit y of 78% based on t he constr ucte d phyloge nic tree . Sp ec tral anal ys is ind ica te d that the thr ee ba cter ia ha d ba cter io ch lorophyl a and norm al sp ir il loxa nthi n ser ies. Growth in med ium enriched with vitamin and supplemen ted with ben zoa te as their s ole C-s ources wa s bette r t han in me di um witho ut vita min. Benz oate deg ra dati on in me di u m with vita min was ac ce lerated. The ab ility to grow on benzoate withou t added vitam ins ind icated that the bacteria were able to s ynthesize th eir own vitamins.

  11. Gas Bypassing and Circulation of Sand and Char Particles in a Dual System with Fluidized Bed and Pneumatic Transport – Effects of Design and Operation Parameters

    Czech Academy of Sciences Publication Activity Database

    Svoboda, Karel; Kalisz, S.; Martinec, J.; Pohořelý, Michael

    Praha : Process Engineering Publisher, 2008, s. 955. ISBN 978-80-02-02050-9. [18th International Congress of Chemical and Process Engineering CHISA 2008. Praha (CZ), 24.08.2008-28.08.2008] Grant ostatní: ECRD(XE) RFCR-CT-2007-00005 Institutional research plan: CEZ:AV0Z40720504 Keywords : circulating flow * solids * fluidized bed Subject RIV: CI - Industrial Chemistry, Chemical Engineering

  12. Oxy-coal combustion in an entrained flow reactor: Application of specific char and volatile combustion and radiation models for oxy-firing conditions

    OpenAIRE

    Álvarez González, Lucía; Yin, C.; Riaza Benito, Juan; Pevida García, Covadonga; Pis Martínez, José Juan; Rubiera González, Fernando

    2013-01-01

    The deployment of oxy-fuel combustion in utility boilers is one of the major options for CO2 capture. However, combustion under oxy-firing conditions differs from conventional air-firing combustion, e.g., in the aspect of radiative heat transfer, coal conversion and pollutants formation. In this work, a numerical study on pulverised coal combustion was conducted to verify the applicability and accuracy of several sub-models refined for oxy-fuel conditions, e.g., gaseous radiative property mod...

  13. Development of a high-performance, coal-fired power generating system with a pyrolysis gas and char-fired high-temperature furnace

    Energy Technology Data Exchange (ETDEWEB)

    Shenker, J.

    1995-11-01

    A high-performance power system (HIPPS) is being developed. This system is a coal-fired, combined-cycle plant that will have an efficiency of at least 47 percent, based on the higher heating value of the fuel. The original emissions goal of the project was for NOx and SOx to each be below 0.15 lb/MMBtu. In the Phase 2 RFP this emissions goal was reduced to 0.06 lb/MMBtu. The ultimate goal of HIPPS is to have an all-coal-fueled system, but initial versions of the system are allowed up to 35 percent heat input from natural gas. Foster Wheeler Development Corporation is currently leading a team effort with AlliedSignal, Bechtel, Foster Wheeler Energy Corporation, Research-Cottrell, TRW and Westinghouse. Previous work on the project was also done by General Electric. The HIPPS plant will use a high-Temperature Advanced Furnace (HITAF) to achieve combined-cycle operation with coal as the primary fuel. The HITAF is an atmospheric-pressure, pulverized-fuel-fired boiler/air heater. The HITAF is used to heat air for the gas turbine and also to transfer heat to the steam cycle. its design and functions are very similar to conventional PC boilers. Some important differences, however, arise from the requirements of the combined cycle operation.

  14. Charred wood remains in the natufian sequence of el-Wad terrace (Israel): New insights into the climatic, environmental and cultural changes at the end of the Pleistocene

    Science.gov (United States)

    Caracuta, Valentina; Weinstein-Evron, Mina; Yeshurun, Reuven; Kaufman, Daniel; Tsatskin, Alexander; Boaretto, Elisabetta

    2016-01-01

    The major social and economic changes associated with the rise of a sedentary lifestyle and the gradual transition to food production in the southern Levant are often considered to have been triggered by climate changes at the end of the Pleistocene (∼20,000-11,000 years BP). This explanation, however, is biased by the scarcity of high-resolution climate records directly associated with human activity and the lack of refined palaeoecological studies from multi-stratified sites in the area. Here, we present the results of an anthracological analysis, carried out on charcoals collected along a continuous column of archaeological sediments in the Natufian site of el-Wad Terrace (Mount Carmel, Israel). We also present the carbon isotopes analysis of 14C-dated archaeological remains of Amygdalus sp. The analyses of charcoal shows the predominance of an oak forest including Quercus calliprinos and ithaburensis around the site during the Early Natufian building phase (∼14,600-13,700 cal BP), and the values of Δ13C point to a high rainfall rate. This period is followed by a marked decrease in the local rainfall between ∼13,700 and 12,000 cal BP). The reduction, culturally associated with the latest Early Natufian and the Late Natufian, is independently recorded by the speleothems of the region: Soreq Cave and Jerusalem Cave. This period incorporates an increase in drought tolerant species such as Amygdalus sp. Thermo-Mediterranean species, such as Olea europaea and Ceratonia siliqua, as well as Pistacia palaestina, which dominate the modern landscape, become established in the Holocene. We conclude that the Natufian settlement at el-Wad Terrace flourished in the context of oak forests, and subsequently occupation intensity decreased in concurrence to the drying trend. This shift does not correspond to the cultural typology (i.e. Early Natufian vs. Late Natufian). Human response to climate change at the terminal Pleistocene Levant was multifaceted and localized. Its understanding requires the analysis of records that are well-tied to human ecology and behavior.

  15. TGA study on copyrolysis of coal and coke-oven gas. II. Combustion reactivity of chars from coal copyrolysis with coke-oven gas

    Energy Technology Data Exchange (ETDEWEB)

    Liao, H.; Sun, C.; Li, B.; Liu, Z. [Chinese Academy of Sciences, Taiyuan (China). State Key Laboratory of Coal Conversion, Institute of Coal Chemistry

    1997-12-01

    At pressures of 0.1-5 MPa, heating rates of 5-25{degree}C/min and a final temperature of 800{degree}C, copyrolysis behaviour of three Chinese coals with real coke-oven gas (COG) were investigated in detail by using thermogravimetric analysis (TGA) and compared with hydropyrolysis under comparable conditions. The results indicated that the reaction pressure and heating rate have significant effects on copyrolysis behaviour. With a raising pressure and a decreasing heating rate the total conversion increases. There is a co-effect on copyrolysis between pressure and heating; by decreasing the heating rate higher conversion can be obtained at low pressure than at high pressure with high heating rate. To increase the total conversion of the copyrolysis, high pressure and low heating rate can be used. Xianfeng and Huangxian lignite are more easy to pyrolyze than Yanzhou bituminous coal under COG. Compared with hydropyrolysis under comparable conditions, the total conversion of the copyrolysis slightly decreases and the peak temperatures in DTG move toward the low temperature region. 4 refs., 5 figs., 2 tabs.

  16. Linking wood source and charring temperature to the stability and biological reactivity of PyOM in a temperate forest soil.

    Science.gov (United States)

    Gibson, Christy; Filley, Timothy; Hatton, Pierre Joseph; Nadelhoffer, Knute; Stark, Ruth; Bird, Jeffrey

    2015-04-01

    Fire is a major mediator of carbon (C) and nitrogen (N) cycling in forests, releasing significant quantities of greenhouse gases, soot, and aerosols while simultaneously depositing pyrogenic organic matter (PyOM) onto forest soil. The condensed aromatic structure of PyOM imparts a resistance to weathering and decay and potentially promotes soil C stabilization and sequestration. This resistance however, is largely dependent upon the physiochemical characteristics of source material and production temperature. Few studies have been able to determine the stability and reactivity of well-characterized PyOM in field or laboratory decay studies. To address this, we added highly 13C-enriched red maple (RM) or jack pine (JP) pyrolyzed at 200, 300, 450 or 600°C to a low C, near-surface soil (0.5%; 0-20 cm-depth) at 60% water holding capacity and 11% of native soil C. We then incubated the samples in the dark at 25°C for 6 months. The results of 13CO2 evolution measurements indicated that both pyrolysis temperature and wood species played a significant role in PyOM mineralization. PyOM mineralization rates decreased with increasing pyrolysis temperature for either species. RM mineralization rates were consistently greater (~5 to ~25%) than for JP soil.

  17. Circulation of Sand and Char Particles in a System with Fluidized Bed and Pneumatic Transport - Effects of Design and Operation Parameters.

    Czech Academy of Sciences Publication Activity Database

    Svoboda, Karel; Kalisz, S.; Martinec, J.; Baxter, D.; Miccio, F.

    Bratislava : Slovak Society of Chemical Engineering, 2007 - (Markoš, J.; Štefuca, V.), s. 260 ISBN 978-80-227-2640-5. [International Conference of Slovak Society of Chemical Engineering /34./. Tatranské Matliare (SK), 21.05.2007-25.05.2007] Institutional research plan: CEZ:AV0Z40720504 Keywords : circulating flow * solids * fluidized bed Subject RIV: CI - Industrial Chemistry, Chemical Engineering

  18. 单宁与聚磷酸铵复配体系对聚丁二酸丁二酯的催化成炭作用%Catalytic Charring Effect of Tannin and Ammonium Polyphosphate on Poly(Butylene Succinate)

    Institute of Scientific and Technical Information of China (English)

    冉诗雅; 陈超; 徐灵钢; 郭正虹

    2014-01-01

    采用热失重分析仪、微型量热仪及扫描电镜研究了单宁(Tannin)与聚磷酸铵(APP)复配体系对聚丁二酸丁二酯(PBS)的催化成炭作用以及炭层对其燃烧行为的影响.热失重分析表明,无论在空气还是氮气下,APP与Tannin复配使用都可以催化PBS体系成炭.当APP与Tannin的质量比为3∶1时,在空气中PBS体系700℃时残炭的实验值为9.3%,在氮气中残炭的实验值为11.3%,都远远高于理论计算值.微型量热仪分析显示,炭层可以作为基体与火焰之间的屏障,尤其当APP与Tannin的比例为5∶1时,PHRR降低了33%.此外,残炭形貌分析表明,APP和Tannin复配使用后,材料表面形成较为均匀、致密的炭层结构.

  19. A Brief Discussion on the Morphological Structure Char-acteristics of Cellphone Short Messages in German%浅谈德语手机短信的词法结构特点

    Institute of Scientific and Technical Information of China (English)

    阮贞

    2014-01-01

    With the development of contemporary science and technology, the methods of human communication are diversified, but cellphone communication occupies an important position in the variety of communication methods. Short messages, as a bridge and medium for human communication, have formed a new style of language in specific contexts when conveying infor-mation and emotions. This paper mainly analyzed cellphone short messages in German from the perspective of morphology, aiming to reveal the characteristics of German short messages in mor-phological structure.%随着当代科技的发展,人类通讯方式呈现出多样化趋势。然而手机通讯在人们众多交流方式中占有重要地位。短信作为人类交流的一座桥梁和一种媒介不仅能够传递信息和情感,同时在具体语境中形成了一种新兴语体。本文着重从词法角度对德语手机短信用语进行分析,意在揭示德语短信在构词上的特点。

  20. Study on Characteristics of Pyrolytic Char from Pyrolysis of Scrap Tires in a Pilot-Scale Rotary Kiln%废轮胎中试回转窑热解炭特性分析

    Institute of Scientific and Technical Information of China (English)

    文世恩; 池涌; 张志霄; 高雅丽; 李水清; 严建华; 岑可法

    2003-01-01

    采用中试回转窑热解装置对废轮胎进行了热解研究.在450~650 ℃热解试验温度范围内,热解炭产率约为390  0~440  0.热解炭的工业及元素分析显示,热解炭中灰分含量高达100  0以上;含量最多的金属元素是Zn和Fe;热解炭S含量2.20  0~2.60  0左右,轮胎原料中S元素约750  0残留在热解炭中,因此热解过程中排放出的气体硫化物很少.此外,探讨了热解炭孔容积分布和温度对比表面积的影响.在450~550 ℃,热解炭比表面积随热解温度升高而增大;温度继续升高,比表面积变化不大.在孔半径约为25 nm处,热解炭比孔容积有最大值.

  1. Les techniques traditionnelles de captage et de partage des eaux d'irrigation dans l'Oasis de Béni Ounif (Région de Béchar, Sud-Ouest, Algérie

    Directory of Open Access Journals (Sweden)

    REZZOUG CHERIF

    2014-08-01

    Full Text Available Traditional techniques of capture and sharing of waters of the oasis of Béni Ounif. For centuries, the oasis dwellers of the Béni Ounif used techniques for acquisition of groundwater to meet the domestic needs of the population of Ksar and garden irrigation. The oasis dwellers were able to master the management of water through these processes. Despite a low annual rainfall, they were able to manage critical situations of prolonged droughts while protecting their environment. These ancient techniques such as traditional wells including foggaras have proven effective in the past. However with the addition of modern methods of water catchment (boreholes and pumps, the ancestral techniques of irrigation degraded from one year to another and their future is threatened. The use of new systems of pumping of groundwater by drilling, and not taken into effective charge of Foggaras, made this system to lose its value which deteriorates while the palm groves disappear. The overpumping causes a significant decrease of the level of the groundwater. Soil salinization is widespread throughout the oasis and water pollution has even reached the whole tablecloth of the oasis. Over 80% of these systems have been abandoned in recent years. However, during the years 2007 and 2008, different rehabilitation projects have been launched by the concerned departments and even some oasis dwellers have started processes to maintain several foggaras, sources and seguias. This study aims to analyze the traditional techniques of capture and sharing of waters of the oasis of Béni Ounif.

  2. The Effect of sewage sledge bio-char as mulch and top-soil incorporated on Soil Physical Characteristics and plant growth in a loss soil with high specific surface area in a temperate climate.

    Science.gov (United States)

    Fathi, Hamed; Movahedi Naeini, Seyed Alireza; Mirzanejad, Mojan

    2015-04-01

    Incorporation of biochar into agricultural soils has been proposed as a potential best management practice (BMP) to increase crop yield and sequester atmospheric carbon (C). Furthermore, the production of biochar, referred to as pyrolysis, yields biofuel that can offset fossil fuels. Current research involving biochar and soil is field scale experiments. Here, sewage sledge biochar was incorporated into a field-scale soybean (Glycine max) system for analysis of soil mechanical and hydrological properties correlated with crop yield. A randomized complete block design was implemented with two biochar application rates: 0 Mg ha-1 (TC), and 25 Mg ha-1 (MTB25 Mulch and ITB25 Incorporated). All plots were tilled using a tractor and rotovator in order to attain uniform incorporation of biochar. A small adjacent field was managed with no-till practices (NTC) to quantify the effects of tillage. Biochar is an effective soil conditioner, evident by MTB25 soil bulk density 9% and 18.5% less than that of TC and NTC, respectively. Analysis of soil pore size distribution resulted in MTB25 with significantly increased macro-pores (1500 μm) related to water transmission and micro-pores (0.5 μm) related to water retention. Furthermore, plant available water capacity (AWC) of MTB25 significantly increased by 9.6% and 29% over TC and NTC, respectively. Biochar amendment (MTB25) increased saturated hydraulic conductivity (Ks) by 33% and 78% over TC and NTC, respectively. Soybean above-ground biomass and grain yield of MTB25 resulted in respective 12.3% and 12.5% increases over TC. The results also showed that the ITB25 was less effective than MTB25. Correlation and linear regression analysis revealed significant positive trends with AWC, soil bulk density, total porosity, among other properties. Results suggest biochar is an effective soil amendment for temperate agricultural soils, yet long-term research will provide additional insight into the potential for biochar to improve soil quality, sequester atmospheric carbon, and enhance crop yield.

  3. Disease: H00555 [KEGG MEDICUS

    Lifescience Database Archive (English)

    Full Text Available H00555 Char syndrome Char syndrome is a rare autosomal dominant disorder characterized by a comb ... of three major features: typical facial features, patent ... ductus arteriosus, and hypoplasia of the middle ph ... in TFAP2B cause Char syndrome, a familial form of patent ... ductus arteriosus. Nat Genet 25:42-6 (2000) PMID:2 ...

  4. Coal type and burnout performance

    Energy Technology Data Exchange (ETDEWEB)

    Lester, E.; Cloke, M. [University of Nottingham, Nottingham (United Kingdom). School of Chemical, Environmental and Mining Engineering

    1999-07-01

    A variety of coals underwent refire tests in a drop tube furnace. Characteristics of the coal fractions, the pyrolysed char fractions and the refired char fractions were compared to determine links between coal composition, intermediate char products and burnout. 9 refs., 1 fig., 2 tabs.

  5. Development of Acid Functional Groups and Lactones During the Thermal Degradation of Wood and Wood Components

    Science.gov (United States)

    Rutherford, David W.; Wershaw, Robert L.; Reeves, James B., III

    2008-01-01

    Black carbon (pyrogenic materials including chars) in soils has been recognized as a substantial portion of soil organic matter, and has been shown to play a vital role in nutrient cycling; however, little is known concerning the properties of this material. Previous studies have largely been concerned with the creation of high-surface-area materials for use as sorbents. These materials have been manufactured at high temperature and have often been activated. Chars occurring in the environment can be formed over a wide range of temperature. Because it is extremely difficult to isolate black carbon once it has been incorporated in soils, chars produced in the laboratory under controlled conditions can be used to investigate the range of properties possible for natural chars. This report shows that charring conditions (temperature and time) have substantial impact on the acid functional group and lactone content of chars. Low temperatures (250?C) and long charring times (greater than 72 hours) produce chars with the highest acid functional group and lactone content. The charring of cellulose appears to be responsible for the creation of the acid functional group and lactones. The significance of this study is that low-temperature chars can have acid functional group contents comparable to humic materials (as high as 8.8 milliequivalents per gram). Acid functional group and lactone content decreases as charring temperature increases. The variation in formation conditions expected under natural fire conditions will result in a wide range of sorption properties for natural chars which are an important component of soil organic matter. By controlling the temperature and duration of charring, it is possible to tailor the sorption properties of chars, which may be used as soil amendments.

  6. Contrasting effects of black carbon amendments on PAH bioaccumulation by Chironomus plumosus larvae in two distinct sediments: Role of water absorption and particle ingestion

    International Nuclear Information System (INIS)

    Two sediment matrices with different characteristics were amended with chars from different sources for bioaccumulation assay with filter-feeding Chironomus plumosus larvae. Chars greatly decreased porewater concentrations of PAHs (Ciw) measured using polyethylene devices in sediments. In organic rich sediment matrix-based systems where suspended char particles were absent, PAH concentrations in larvae (CiB) were significantly correlated with Ciw, and there was no difference in water-based bioaccumulation factors (BAFs) between different treatments, suggesting that water absorption was the main contaminant uptake route for larvae. In organic poor sediment matrix-based systems where suspended char particles were present, poor Pearson correlation between CiB and Ciw was found, but there was a significant linear increase of BAF values with char contents, which indicated that ingestion of suspended char particles could also be important for PAH bioaccumulation. Therefore, we need to rethink of the effectiveness and risks for the application of black carbon to sediment/soil remediation. - Highlights: → Chars greatly decreased PAH porewater concentrations. → Without char suspension, PAH bioaccumulation depended on porewater concentrations. → With char suspension, ingestion could also be important for PAH bioaccumulation. - Contrasting effects of chars on PAH bioaccumulation by Chironomus plumosus larvae in two distinct sediments were attributed to the shift of main biouptake routes.

  7. Dynamic molecular structure of plant biomass-derived black carbon (biochar)

    Energy Technology Data Exchange (ETDEWEB)

    Keiluweit, M.; Nico, P.S.; Johnson, M.G.; Kleber, M.

    2009-11-15

    Char black carbon (BC), the solid residue of incomplete combustion, is continuously being added to soils and sediments due to natural vegetation fires, anthropogenic pollution, and new strategies for carbon sequestration ('biochar'). Here we present a molecular-level assessment of the physical organization and chemical complexity of biomass-derived chars and, specifically, that of aromatic carbon in char structures. BET-N{sub 2} surface area, X-ray diffraction (XRD), synchrotron-based Near-edge X-ray Absorption Fine Structure (NEXAFS), and Fourier transform infrared (FT-IR) spectroscopy are used to show how two plant materials (wood and grass) undergo analogous, but quantitatively different physical-chemical transitions as charring temperature increases from 100 to 700 C. These changes suggest the existence of four distinct categories of char consisting of a unique mixture of chemical phases and physical states: (i) in transition chars the crystalline character of the precursor materials is preserved, (ii) in amorphous chars the heat-altered molecules and incipient aromatic polycondensates are randomly mixed, (iii) composite chars consist of poorly ordered graphene stacks embedded in amorphous phases, and (iv) turbostratic chars are dominated by disordered graphitic crystallites. The molecular variations among the different char categories translate into differences in their ability to persist in the environment and function as environmental sorbents.

  8. Reactivity and burnout of wood fuels

    DEFF Research Database (Denmark)

    Dall'Ora, Michelangelo

    reactivity. Char yield from fast pyrolysis (104 – 105 K/s) was as low as 1 to 6 % on a dry ash free basis, whereas it was about 15-17 % for slow pyrolysis (10 - 20 K/min); char yield decreased as pyrolysis temperature increased. During fast pyrolysis wood particles underwent melting, yet to different extents....... Fast pyrolysis chars were significantly more reactive than slow pyrolysis chars (for the same activation energy, the pre-exponential factor was up to 2 orders of magnitude greater for chars increased. The amount and composition of the ash forming matter of the wood fuels is believed to play an......This thesis deals with the combustion of wood in pulverised fuel power plants. In this type of boiler, the slowest step in the wood conversion process is char combustion, which is one of the factors that not only determine the degree of fuel burnout, but also affect the heat release profile in the...

  9. 固形産業廃棄物の熱炭化中間物の有効利用システムに関する研究

    OpenAIRE

    王, 青躍; 金田, 昌之; 中家, 良忠; 遠藤, 浩志

    2002-01-01

    Many solid organic industrial wastes discarded from various industries in Japan are pyrolyzed and/or carbonized for the putposes of emission reduction, safety and reuse. The objective of this study is to establish the utilization system of intermediates or chars carbonized from these wastes using a pyrolysis device with over-heated steam. This pre-feasibility study suggested that char-biomass briquette (CBB) produced from the carbonized intermediates or chars ofwaste tire chips are available ...

  10. Study on the submicron and micron morphology and the properties of poor bituminous coal burnout

    Energy Technology Data Exchange (ETDEWEB)

    Pei-Fang Fu; Huai-Chun Zhou; Qing-Yan Fang; Hai Yao; Jianrong Qiu; Minghou Xu [Huazhong University of Science and Technology, Wuhan (China). State Key Laboratory of Coal Combustion

    2007-05-15

    Carbon burnout and its reaction mechanism have been widely focused on in the past decades. The properties of burnout, submicron and micron morphology and the reaction mechanism of poor bituminous coal/char (PBC) in a W-shaped power plant boiler was studied and was compared with those in DTF and in TGA, which showed that the degree of PBC burnout in TGA at 1450{sup o}C was greater than or approximately equal to that in a W-shaped boiler, and that the complexity of the reactions among residual char, oxygen and SiO{sub 2} did not seem to result in mass loss in TGA, although the weight percentage of the residual char in ash decreased from 33% ad (air dry basis) at 900{sup o}C to 9% and at 1450{sup o}C. According to the distribution of pores and the properties of the char burnout, the char can be simply categorized into three classes: char burnout easy, char burnout difficult and char burnout very difficult. The differences of the reaction mechanism must be considered while predicting the burning rate and degree of char burnout in a full-scale boiler by making use of experimental results from TGA and DTF. A different char particle contains markedly different amount of carbons, but for a special char particle, the ratio of carbon to ash is generally constant, and an ash shell does not exist on the char surface. The fusion mineral matter composing of C-O-Si-Al is amorphous, not in the form of Al{sub 2}O{sub 3} and SiO{sub 2} above 1450{sup o}C.

  11. Sorption Characteristics of Activated Carbon Obtained from Rice Husks by Treatment with Lime

    International Nuclear Information System (INIS)

    The sorption studies of rice husk char prepared by carbonization and activation with lime, caustic soda and sulphuric acid have been investigated. Prior to impregnation with the lime; on a micro processing scale the pre-carbonization temperature of rice husk were determined by using TG-DTA thermal analysis. The impregnation with chemical was made after carbonization and the impregnated chars were subjected to activation at appropriate temperatures of about 300 C to 500 C depending on the impregnated chars. The physico-chemical properties of the prepared chars were tested by conventional and modern techniques. Sorption capacities with respect to colored dyes were determined for each of the char. These sorption capacities are indicative of the decolorizing nature and the acid or basic nature. The sorption capacities of the prepared chars towards the uptake of metals such as copper, iron, lead and cadmium were also studied and the lime activated char exhibits high adsorptive capacities for all the metals compared to other prepared chars as well as the commercial wood char. The evaluation of the sorption capacities of this chars were made on the basis of Freundlich and Langmuir monolayer coverage equations. Thus, based on batch dosage method and breakthrough flow method, the uptake of the metals were found to be in following order for the lime activated rice husk char; Cu > Fe > Pb > Cd. From this investigation, it can be inferred that a rice husk char impregnated with 20% technical grade CaO has the potential effect to be used as an effective metal adsorbent particularly for the uptake of toxic heavy metals in the secondary stage of water treatment processes.

  12. Treatment of Mixed Wastes via Fixed Bed Gasification

    Energy Technology Data Exchange (ETDEWEB)

    None

    1998-10-28

    This report outlines the details of research performed under USDOE Cooperative Agreement DE-FC21-96MC33258 to evaluate the ChemChar hazardous waste system for the destruction of mixed wastes, defined as those that contain both RCRA-regulated haz- ardous constituents and radionuclides. The ChemChar gasification system uses a granular carbonaceous char matrix to immobilize wastes and feed them into the gasifier. In the gasifier wastes are subjected to high temperature reducing conditions, which destroy the organic constituents and immobilize radionuclides on the regenerated char. Only about 10 percent of the char is consumed on each pass through the gasifier, and the regenerated char can be used to treat additional wastes. When tested on a 4-inch diameter scale with a continuous feed unit as part of this research, the ChemChar gasification system was found to be effective in destroying RCRA surrogate organic wastes (chlorobenzene, dichloroben- zene, and napht.halene) while retaining on the char RCRA heavy metals (chromium, nickel, lead, and cadmium) as well as a fission product surrogate (cesium) and a plutonium surrogate (cerium). No generation of harmful byproducts was observed. This report describes the design and testing of the ChemChar gasification system and gives the operating procedures to be followed in using the system safely and effectively for mixed waste treatment.

  13. Immobilisation Of Spent Ion Exchange Resins Using Portland Cement Blending With Organic Material

    International Nuclear Information System (INIS)

    Immobilisation of spent ion exchange resins (spent resins) using Portland cement blending with organic material for example bio char was investigated. The performance of cement-bio char matrix for immobilisation of spent ion exchange resins was evaluated based on their compression strength and leachability under different experimental conditions. The results showed that the amount of bio char and spent resins loading effect the compressive strength of the waste form. Several factors affecting the leaching behaviour of immobilised spent resins in cement-bio char matrix. (author)

  14. [Adsorption of methylene blue from water by the biochars generated from crop residues].

    Science.gov (United States)

    Xu, Ren-Kou; Zhao, An-Zhen; Xiao, Shuang-Cheng; Yuan, Jin-Hua

    2012-01-01

    Biochars were prepared from straws of rice, peanut and soybean and rice hull using a low temperature pyrolysis method and adsorption of methylene blue by these biochars were investigated with batch and leaching experiments. Results indicated that biochars have high adsorption capacity for methylene blue and followed the order: rice straw char > soybean straw char > peanut straw char > rice hull char. This order is generally consistent with the amount of negative charge and specific surface area of these biochars. While methylene blue was mainly adsorbed specifically by the biochars, because the adsorption of methylene blue increased with the increase of ionic strength and the adsorption led to the shift of zeta potential of biochar particles to positive value direction. Langmuir equation fitted the adsorption isotherms well and can be used to describe the adsorption behaviors of methylene blue by the biochars. The maximum adsorption capacity of methylene blue predicted by langmuir equation was 196.1, 169.5, 129.9 and 89.3 mmol x kg(-1) for rice straw char, soybean straw char, peanut straw char and rice hull char, respectively. Leaching experiments show that rice hull char of 156 g can remove methylene blue from 30 L water containing 0.3 mmol x L(-1) of methylene blue completely and the cumulative amount of methylene blue absorbed by the biochar reaches 57.7 mmol x kg(-1). The biochars can be used as efficient adsorbents to remove methylene blue from waste water of dye. PMID:22452202

  15. Characterization and quantification of biomarkers from biomass burning at a recent wildfire site in northern Alberta, Canada

    Energy Technology Data Exchange (ETDEWEB)

    Otto, A.; Gondokusumo, R.; Simpson, M.J. [University of Toronto (Canada). Scarborough College

    2006-01-15

    The composition of organic matter (OM) in pine vegetation and soil samples from a pine forest which was charred by a wildfire was analyzed using solid-state nuclear magnetic resonance ({sup 13}C NMR) and gas chromatography-mass spectrometry (GC-MS) of solvent extracts to study the effects of thermal alteration on soil organic matter (SOM). The NMR data revealed the presence of unaltered biomolecules (cellulose, proteins) and low contents of aromatic C (15%) in the charred pine wood and cones while the charred soil samples exhibited higher contents of aromatic C (39-56%). The solvent extraction of charred and uncharred plant and soil samples yielded diterpenoids, triterpenoids, steroids, a series of aliphatic lipids, phenols and carbohydrates indicating the predominant input of higher plant OM and minor contributions from microorganisms and/or fauna. The lower yield of solvent extractable aliphatic lipids in the charred samples versus the uncharred samples suggests that these compounds are thermally degraded during a wildfire. Molecular markers for the burning of cellulose (levoglucosan, mannosan, galactosan) were detected in all charred samples. The comparison of charred and uncharred samples allowed the identification of unaltered pine derived biomolecules and their thermal alteration products in the charred samples. Terpenoid and steroid biomolecules were in part altered during incomplete combustion to aromatic, unsaturated and polar derivatives (pyromolecules'') that still retained the characteristic skeleton of their precursors. Since some of the polar degradation products found in the charred soils can be generated either from thermal or microbial degradation, the aromatic and unsaturated hydrocarbon products are preferred as molecular markers for SOM burning. Ratios of biological precursors to aromatic (diterpenoids) or unsaturated products (steroids) indicate that the cyclic lipids in the pine wood and the soil surface horizon were highly altered

  16. Fundamental studies of catalytic gasification: Quarterly report, October 1, 1986-December 31, 1986

    Energy Technology Data Exchange (ETDEWEB)

    Heinemann, H.

    1986-12-01

    This program studies the basic chemistry of the reaction of carbonaceous materials with water in the presence of catalysts to produce hydrogen and/or synthesis gas. Relatively low temperatures are being used. The catalysts under investigation are compounds of potassium and a transition metal oxide. Major objectives are the extension of the work from chars to coke; the effect of H/sub 2/, CO and CO/sub 2/ partial pressure on the gaseous product distribution; and the inhibition of catalyst poisoning by ash components. Some of the highlights are: (1) Activation energies for K/Ni catalyzed steam gasification of graphite and of chars are identical, indicating the same mechanism prevails though rates are much higher for chars. This permits extrapolation of findings in high vacuum equipment from graphite to chars. (2) The CO/CO/sub 2/ ratio of gases produced along with hydrogen varies with different chars. The ratio is 0.8 for Illinois No. 6 char and 0.08 for North Dakota char. Methane production is several orders of magnitude smaller and ceases after about 2 hours. (3) Comparison of K/Ni catalyst for steam gasification of Illinois No. 6 char with K or Ni alone indicates: (a) K alone produces much higher CO/CO/sub 2/ ratios than K/Ni. (b) Ni alone is almost inactive for the steam gasification of Illinois No. 6 except for the short first period of operation. (4) Montana char treated with aqua regia to remove ash components prior to impregnation with K/Ni has 75% of the activity of untreated char but exhibits little deactivation with time so that it gasifies better than untreated char after a few hours. (5) Controlled atmosphere electron microscopy studies have been extended to wet hydrogen and wet oxygen treatments of K/Ni impregnated graphite 3 refs., 8 figs., 2 tabs.

  17. Kinetics of the steam gasification of a phenolic circuit board in the presence of carbonates

    International Nuclear Information System (INIS)

    Highlights: ► The gasification was effective to produce clean hydrogen from plastic WEEE content. ► The reaction proceeded through an initial pyrolysis and latter gasification of char. ► Both the pyrolysis and the latter gasification were accelerated by the carbonate. ► Physical contact of steam, carbonate and char was important for the gasification. ► The gasification occurred mainly in outer layer of char infiltrated by the carbonate. -- Abstract: Steam gasification of a phenolic board in the presence of molten carbonate was studied as a means to recover useful metals effectively from electronic waste while also converting its plastic fraction into clean fuel gas. In the steam gasification of the phenolic board, the presence of carbonate considerably accelerated the conversion of tar and char into gaseous products. When pulverized phenolic board particles <0.15 mm were gasified, carbonate and steam permeated the sample particles, and the resulting gasification proceeded was well modeled by a homogeneous kinetic model. On the other hand relatively large phenolic board particles appeared to undergo two different hydrogen-producing gasification processes: the observed hydrogen formation rates suggest that an initial gasification occurred in the surface layer, which carbonate and steam were able to infiltrate into, and after this layer was consumed, the gasification proceeded only on the surface of the resulting char. The reactivity of char in the steam gasification depends sensitively on the conditions whereby the char is produced: rapid pyrolysis of the phenolic board produced highly reactive char, evidenced by markedly increased hydrogen formation rates in the steam gasification of chars formed under more rapid heating. However, once the char was pulverized finely, no obvious difference in reactivity was observed in the steam gasification based on the size of the phenolic board particles used to produce the char.

  18. Production of carbon molecular sieves from Illinois coal. Final technical report, 1 September, 1992--31 August 1993

    Energy Technology Data Exchange (ETDEWEB)

    Lizzio, A.A.; Rostam-Abadi, M. [Illinois State Geological Survey, Champaign, IL (United States)

    1993-12-31

    Carbon molecular sieves (CMS) have become an increasingly important class of adsorbents for use in gas separation and recovery processes. The overall objective of this project is to determine whether Illinois Basin coals are a suitable feedstock for the production of CMS and to evaluate the potential application of these products in commercial gas separation processes. In Phase 1 of this project, gram quantities of char were prepared from Illinois coal in a fixed-bed reactor under a wide range of pyrolysis and activation conditions. Chars having surface areas of 1,500--2,100 m{sup 2}/g were produced by chemical activation using potassium hydroxide (KOH) as the chemical activant. These high surface area (HSA) chars had more than twice the adsorption capacity of commercial molecular sieves. The kinetics of adsorption of various gases, e.g., O{sub 2}, N{sub 2}, CO{sub 2}, CH{sub 4}, and H{sub 2}, on these chars at 25 C was determined. Several chars showed good potential for efficient O{sub 2}/N{sub 2}, CO{sub 2}/CH{sub 4} and CH{sub 4}/H{sub 2} separation. In Phase 2 of this project, larger quantities of char are being prepared from Illinois coal in a batch fluidized-bed reactor and in a continuous rotary tube kiln. The ability of these chars to separate binary gas mixtures is tested in an adsorption column/gas chromatography system. Oxygen and nitrogen breakthrough curves obtained for selected chars were compared to those of a commercial zeolite. Selected chars were subjected to a nitric acid oxidation treatment. The air separation capability of nitric acid treated char was strongly dependent on the outgassing conditions used prior to an O{sub 2}/N{sub 2} adsorption experiment. An outgassing temperature of 130--160 C produced chars with the most favorable air separation properties. 61 refs.

  19. Characterization and quantification of biomarkers from biomass burning at a recent wildfire site in Northern Alberta, Canada

    International Nuclear Information System (INIS)

    The composition of organic matter (OM) in pine vegetation and soil samples from a pine forest which was charred by a wildfire was analyzed using solid-state nuclear magnetic resonance (13C NMR) and gas chromatography-mass spectrometry (GC-MS) of solvent extracts to study the effects of thermal alteration on soil organic matter (SOM). The NMR data revealed the presence of unaltered biomolecules (cellulose, proteins) and low contents of aromatic C (15%) in the charred pine wood and cones while the charred soil samples exhibited higher contents of aromatic C (39-56%). The solvent extraction of charred and uncharred plant and soil samples yielded diterpenoids, triterpenoids, steroids, a series of aliphatic lipids, phenols and carbohydrates indicating the predominant input of higher plant OM and minor contributions from microorganisms and/or fauna. The lower yield of solvent extractable aliphatic lipids in the charred samples versus the uncharred samples suggests that these compounds are thermally degraded during a wildfire. Molecular markers for the burning of cellulose (levoglucosan, mannosan, galactosan) were detected in all charred samples. The comparison of charred and uncharred samples allowed the identification of unaltered pine derived biomolecules and their thermal alteration products in the charred samples. Terpenoid and steroid biomolecules were in part altered during incomplete combustion to aromatic, unsaturated and polar derivatives ('pyromolecules') that still retained the characteristic skeleton of their precursors. Since some of the polar degradation products found in the charred soils can be generated either from thermal or microbial degradation, the aromatic and unsaturated hydrocarbon products are preferred as molecular markers for SOM burning. Ratios of biological precursors to aromatic (diterpenoids) or unsaturated products (steroids) indicate that the cyclic lipids in the pine wood and the soil surface horizon were highly altered. In conclusion

  20. Investigation of reform of the Pharmac ology education based on the char-acteristic of Chinese higher institutions for minorities%基于我国民族院校的特点探讨《药理学》课程的教改思路

    Institute of Scientific and Technical Information of China (English)

    邓旭坤; 袁琳; 陈旅翼; 唐和斌; 林亲雄; 胡鑫; 黄先菊; 杨光忠

    2014-01-01

    中国民族院校是为少数民族和民族地区培养高素质人才的重要基地,然而,当前普遍存在的学生生源质量较差、学生层次参差不齐、基础薄弱、知识背景欠缺、学习和动手能力较差等特点,限制了民族院校专业课教学质量的提高。本文针对这些突出问题,对症下药,结合近几年笔者在民族院校教授《药理学》取得的一些经验和体会,综合CAI、CPT、PBL、UTST、EL等国际先进教育理念和教学方法,积极寻找适合民族院校特点的《药理学》教学规律和手段,探讨改变传统教学中填鸭式的教学模式,充分调动民族院校学生的积极性和主动性,提高学生学习兴趣,培养学生自主性能力及创新思维和意识的教学改革思路,最终达到保证和提高民族院校的《药理学》教学质量和教学效果的目的。%Chinese higher institutions for minorities are the basic places to nurture the higher talents for the minorities in China.However,there are many characteristics and defect to hinder boosting its quality of pharmacology teaching, such as many students are from poorer and remote area and low quality,as well as remarkable difference of them are very prominent.What is more,their intellectual context,comprehension and practical ability are not well.Therefore,refor-mation measures must be put forward to improve the quality of pharmacology education and cultivate interesting and the practical ability of students according to this situation of Pharmac ology education in minority higher institutions. This paper was written to provide reference for the reform of Pharmac ology teaching based on the characteristic of Chi-nese higher institutions for minorities.In this paper,multiple advanced methods of Pharmac ology education were taken, such as adopting elicitation method of teaching (CBT,PBL,UTST,EL),reforming laboratory course and increasing multi-media teaching(CAI).Pharmacology education should be optimized and effective to cultivate interesting and autonomous learning ability of students, and to boost the quality in the teaching of Pharmac ology in higher institutions for minorities.

  1. FTIR显微技术在阻燃木材炭化过程及阻燃剂渗透研究中的应用%Application of FTIR Microscopy in the Research of Charring of Fire Retardant Wood and Penetration of Fire Retardant into Wood

    Institute of Scientific and Technical Information of China (English)

    王清文; 谢延军; 李淑君; 李坚

    2000-01-01

    采用博里叶变换红外光谱(FTJR)显微技术获得了FRW阻燃末材及其炭化产物的微区FTIR谱.用微区FTIR谱法测定了FRW阻燃木材中FRW阻燃剂的渗透深度.测定精度达O.2mm.方法准确而快速,通过解析FRw阻燃末材不同炭化阶段产物的微区FTIR谱.推断其结构特征.进而讨论了FRw阻燃木材的炭化过程.

  2. Comparison of biochar formation from various agricultural by-products using FTIR spectroscopy

    Science.gov (United States)

    Biochar is charred material produced by the pyrolysis of organic biomass. In this work, Fourier transform infrared (FTIR) spectra of different agricultural by-products feedstock and their derived biochars were collected to explore the potential of FTIR technique as a simple and rapid method for char...

  3. Modeling N2O Reduction and Decomposition in a Circulating Fluidized bed Boiler

    DEFF Research Database (Denmark)

    Johnsson, Jan Erik; Åmand, Lars-Erik; Dam-Johansen, Kim; Leckner, Bo

    1996-01-01

    . The conclusion is that in the bottom part of the combustor, where the solids concentration is about 1000 kg/m3 and the char content 2 wt%, heterogeneous reactions were the most important N2O destruction mechanisms. Reduction by char accounted for 80% of the N2O destruction, 20 % was due to catalytic...

  4. ON-SITE PRODUCTION OF ACTIVATED CARBON FROM KRAFT BLACK LIQUOR

    Science.gov (United States)

    A pilot plant was designed and constructed to produce char via the St. Regis hydropyrolysis kraft chemical recovery process and to produce activated carbon from the char. This report includes discussion of laboratory and prepilot work, the pilot plant, and presents operating resu...

  5. HOUSEHOLD PURIFICATION OF FLUORIDE CONTAMINATED MAGADI (TRONA)

    DEFF Research Database (Denmark)

    Nielsen, Joan Maj; Dahi, Elian

    1997-01-01

    Purification of fluoride contaminated magadi is studied using bone char sorption and calcium precipitation. The bone char treatment is found to be workable both in columns and in batches where the magadi is dissolved in water prior to treatment. The concentrations in the solutions were 89 g magadi...... treatment method. A procedure for purification of fluoride contaminated magadi at household level is described....

  6. Process for converting coal into liquid fuel and metallurgical coke

    Science.gov (United States)

    Wolfe, Richard A.; Im, Chang J.; Wright, Robert E.

    1994-01-01

    A method of recovering coal liquids and producing metallurgical coke utilizes low ash, low sulfur coal as a parent for a coal char formed by pyrolysis with a volatile content of less than 8%. The char is briquetted and heated in an inert gas over a prescribed heat history to yield a high strength briquette with less than 2% volatile content.

  7. Glass fiber addition strengthens low-density ablative compositions

    Science.gov (United States)

    Chandler, H. H.

    1974-01-01

    Approximately 15% of E-glass fibers was added to compositions under test and greatly improved char stability. Use of these fibers also reduced thermal strains which, in turn, minimized char shrinkage and associated cracks, subsurface voids, and disbonds. Increased strength allows honeycomb core reinforcement to be replaced by equivalent amount of glass fibers.

  8. New high-temperature flame-resistant resin matrix for RP/C

    Science.gov (United States)

    Kourtides, D. A.

    1981-01-01

    The processing parameters of graphite composites utilizing graphite fabric and epoxy or other advanced thermoset and thermoplastic resins as matrices are discussed. The evaluated properties include anaerobic char yield, limiting oxygen index, smoke evolution, moisture absorption, and high-temperature mechanical properties. It is shown that graphite composites having the highest char yield exhibit optimum fire-resistant properties.

  9. Effect of temperature on pyrolysis products from four nut shells

    Energy Technology Data Exchange (ETDEWEB)

    Demirbas, Ayhan [Department of Chemical Engineering, Selcuk University, Konya (Turkey)

    2006-06-01

    This article deals with slow pyrolysis of four shells such as hazelnut, walnut, almond and sunflower at the range of temperature 500-1200K in a cylindrical reactor batch reactor. The aim of this work was to experimentally investigate how the temperature affects char, liquid and gaseous product yields from different shells via pyrolysis. The amount of char from pyrolysis of the shell samples decreases with increasing the pyrolysis temperature. The highest liquid yields were obtained from the samples between 650 and 800K. The yield and the chemical composition of char can be calculated as functions of the pyrolysis temperature. The char components and higher heating values (HHVs) of shell fuels were correlated with pyrolysis temperatures. There were highly significant linear correlation between the pyrolysis temperature of the fuel and the fixed carbon content and HHV of char. (author)

  10. Investigation of an Intumescent Coating System in Pilot and Laboratory-scale Furnaces

    DEFF Research Database (Denmark)

    Nørgaard, Kristian Petersen

    , which showed a minor delamination at the edges. In addition, it was shown that the thermogravimetric behavior of the primer and intumescent coating alone could not be used for explaining the entire coating system performance. A novel experimental method, which may potentially be developed into a fast...... was done against experimental char expansion rates and temperatures of the steel substrate and at intra-char positions. The model was solved in a discretized and non-discretized version and a good qualitative description of the temperature curves was found. An important learning was that temperatures...... for the char oxidation reactions. An investigation of the repeatability of the experimental temperatures showed that temperatures close to the char surface were somewhat more uncertain than the steel temperature and char temperatures close to the steel substrate. Chapters 4 and 5 are concerned...

  11. Catalytic Conditioning and Conversion of Bio-Syngas: Cooperative Research and Development Final Report, CRADA Number CRD-10-418

    Energy Technology Data Exchange (ETDEWEB)

    Magrini, Kim [National Renewable Energy Lab. (NREL), Golden, CO (United States)

    2016-08-01

    There is a critical need to increase the carbon yield of the gasification process. To this end, it has been suggested that tars and chars formed as by-products of gasification be re-injected into the gasifier. In this CRADA work facile and inexpensive methods of modifying chars and tars received from Enerkem are studied with the aim of increasing their gasification rate upon re-injection into the gasifier. Adding iron to the char, both in nitrate form and in clay form, speeds the CO2 gasification of the char (CO2 + C --> 2CO). It has been more difficult to speed the gasification of tar mixed with char, likely due to clogging of pores, resulting in a reduced accessible surface area.

  12. Transportation package thermal and shielding response to a regulatory fire

    International Nuclear Information System (INIS)

    The objective of this work is to evaluate the effect of neutron shield charring due to a regulatory fire on the thermal response and shielding effectiveness of a Multi-Purpose Canister (MPC) and transportation cask. A thermal response model which includes the effect of neutron shield charring is developed. The model is solved using a time dependent finite element code. The maximum fuel temperature-time history and the extent of shield charring are determined. This is used to estimate the primary dose rate from the package in the post-fire condition. It is determined that charring has an insignificant effect on the thermal response of the fuel. Furthermore, while charring increases dose rates, these rates remain below Nuclear Regulatory Commission limits for accident conditions

  13. Experimental performance of an ablative material as an external insulator for a hypersonic research aircraft

    Science.gov (United States)

    Puster, R. L.; Chapman, A. J.

    1977-01-01

    An ablative material composed of silica-filled elastomeric silicone was tested to evaluate its thermal and structural performance as an external insulator, or heat shield, for a hypersonic research aircraft. The material was also tested to determine whether it would form a durable char layer when initially heated and thereafter function primarily as an insulator with little further pyrolysis or char removal. Aerothermal tests were representative of nominal Mach 6 cruise conditions of the aircraft, and additional tests were representative of Mach 8 cruise and interference heating conditions. Radiant heating tests were used to simulate the complete nominal Mach 6 surface-temperature history. The silica char that formed during aerothermal tests was not durable. The char experienced a general and preferential surface recession, with the primary mechanism for char removal being erosion. Tests revealed that radiant heating is not a valid technique for simulating aerodynamic heating of the material.

  14. Hydrothermal carbonization and torrefaction of grape pomace: a comparative evaluation.

    Science.gov (United States)

    Pala, Mehmet; Kantarli, Ismail Cem; Buyukisik, Hasan Baha; Yanik, Jale

    2014-06-01

    Grape pomace was treated by hydrothermal carbonization (sub-critical water, 175-275°C) and torrefaction (nitrogen atmosphere, 250 and 300°C), with mass yield of solid product (char) ranging between 47% and 78%, and energy densification ratio to 1.42-1.15 of the original feedstock. The chars were characterised with respect to their fuel properties, morphological and structural properties and combustion characteristics. The hydrothermal carbonization produced the char with greater energy density than torrefaction. The chars from torrefaction were found to be more aromatic in nature than that from hydrothermal carbonization. Hydrothermal carbonization process produced the char having high combustion reactivity. Most interesting was the finding that aqueous phase from hydrothermal carbonization had antioxidant activity. The results obtained in this study showed that HTC appears to be promising process for a winery waste having high moisture content. PMID:24709539

  15. Adsorption of methyl violet from aqueous solutions by the biochars derived from crop residues.

    Science.gov (United States)

    Xu, Ren-kou; Xiao, Shuang-cheng; Yuan, Jin-hua; Zhao, An-zhen

    2011-11-01

    The adsorption of methyl violet by the biochars from crop residues was investigated with batch and leaching experiments--adsorption capacity varied with their feedstock in the following order: canola straw char>peanut straw char>soybean straw char>rice hull char. This order was generally consistent with the amount of negative charge of the biochars. Zeta potentials and Fourier transform infrared photoacoustic spectroscopy, combined with adsorption isotherms and effect of ionic strength, indicated that adsorption of methyl violet on biochars involved electrostatic attraction, specific interaction between the dye and carboxylate and phenolic hydroxyl groups on the biochars, and surface precipitation. Leaching experiments showed that 156 g of rice hull char almost completely removed methyl violet from 18.2 L of water containing 1.0 mmol/L of methyl violet. The biochars had high removal efficiency for methyl violet and could be effective adsorbents for removal of methyl violet from wastewater. PMID:21924897

  16. Effects of different biochars and digestate on N2O fluxes under field conditions.

    Science.gov (United States)

    Dicke, Christiane; Andert, Janet; Ammon, Christian; Kern, Jürgen; Meyer-Aurich, Andreas; Kaupenjohann, Martin

    2015-08-15

    Field studies that have investigated the effects of char materials on the emission of nitrous oxide (N2O) are still scarce. Therefore, we conducted a field trial with bio- and hydrochars and measured N2O emissions for one whole year. It was hypothesised that the incorporation of chars reduces the emissions of N2O. Chars were produced by pyrolysis and hydrothermal carbonisation (HTC) using either maize silage or wood residues as feedstock. In addition, after production chars were post-treated with digestate in order to accelerate the ageing process of the chars. Chars and digestate were applied to the soil to raise the C content. Emissions of N2O were measured weekly and soil samples for inorganic nitrogen (N) and soil water-content were taken once a month. Additionally, the abundance of functional marker genes from denitrification (nosZ) was determined in October 2012 and in June 2013. The treatment with pure digestate emitted the most N2O compared to the control and char treatments. However, this was significant only in one case. There were no great differences between the char treatments due to high spatial variability and gene abundance of nosZ did not differ between treatments. Overall, emissions of N2O were relatively low. This was attributed to the heterogeneous distribution of the chars and the sandy soils that did not favour the production of N2O. To conclude, the emissions of N2O were mainly influenced by temperature and precipitation and to a minor extent by the type of char and post-treatment. PMID:25897736

  17. Use of image analysis on the prediction of coal burnout performance in a drop tube furnace

    Energy Technology Data Exchange (ETDEWEB)

    R. Barranco; M. Cloke; E. Lester [University of Nottingham, Nottingham (United Kingdom). Nottingham Fuel and Energy Centre, SChEME

    2003-07-01

    An experimental investigation in a drop-tube furnace (DTF) into the combustion burnout performance of some South American coals was carried out. The coal samples, mainly from Colombia, were crushed and screened into three size fractions: 53-75 {mu}m, 106-125 {mu}m, and 150-180 {mu}m. These samples were characterised by standard tests along with a specially developed image analysis technique (grey-scale histogram). Pyrolysis of these samples was performed at a temperature of 1300{sup o}C, in a 1% of oxygen in nitrogen atmosphere for 200 ms. The chars obtained were then re-fired in the same apparatus, at the same temperature, at various residence times, in an atmosphere containing 5% of oxygen in nitrogen. The changes in the characteristics of the chars produced were assessed using a number of different techniques including intrinsic reactivity test and automatic char analysis. Despite the fact that all the coals used in this study were vitrinite-rich, variations in char morphology were evident. This demonstrated that it was impossible to assign any one char type to a single maceral group. It was apparent that vitrinite generates a wide range of char types depending upon the rank of the parent coal and on the maceral associations within the coal. In addition, a reactivity parameter, derived from the grey-scale histogram obtained by image analysis of the coal, was found to be important in the prediction of coal combustion behaviour. Some properties of the re-fired chars were compared with morphology and intrinsic reactivity data of the pyrolysed chars. The results showed that the poor burnout of one of the coals was clearly due to the formation of some particular chars during pyrolysis. This confirms the usefulness of high temperature pyrolysis chars as a predictor of burnout performance. 18 refs., 8 figs., 2 tabs.

  18. Effects of fuel properties on the natural downward smoldering of piled biomass powder: Experimental investigation

    International Nuclear Information System (INIS)

    To validate the modeling of one-dimensional biomass smoldering and combustion, the effects of fuel type, moisture content and particle size on the natural downward smoldering of biomass powder have been investigated experimentally. A cylindrical reactor (inner size Φ26 cm × 22 cm) was constructed, and corn stalk, pine trunk, pyrolysis char and activated char from corn stalk were prepared as powders. The smoldering characteristics were examined for each of the four materials and for different moisture contents and particle sizes. The results revealed the following: 1) The maximum temperature in the fuel bed is only slightly affected by the fuel type and particle size. It increases gradually for original biomass and decreases slowly for chars with the development of the process. 2) The propagation velocity of the char oxidation front is significantly affected by the carbon density and ash content and nearly unaffected by moisture content and particle size. 3) The propagation velocity of the drying front is significantly affected by the moisture content, decreasing from over 10 times the propagation velocity of char oxidation front to about 3 times as the moisture content increased from 3 to 21%. - Highlights: • Natural downward smoldering of four materials, different moisture contents, and different particle sizes were investigated. • Propagation velocity of the char oxidation front differs significantly from that of the drying front. • Carbon density and ash content of fuel significantly affect propagation velocity of the char oxidation front

  19. Characterization of porosity via secondary reactions. Quarterly technical progress report, 1 January 1993--31 March 1993

    Energy Technology Data Exchange (ETDEWEB)

    Calo, J.M.; Lu, W.; Zhang, L.

    1993-07-01

    Temperature-programmed desorption spectra from steam-gasified chars were examined. At least two major CO-liberating features were identified for the resin char samples, one centered 1000 C and the other 1050 C. Presence of catalytic mineral matter appears to be related to the appearance of an additional low temperature feature for the Wyodak char. Although total amount of surface oxygen seems to be a gross indicator of reactivity, analysis of the desorption data assuming two different types of oxygen surface complexes, each exhibiting a single desorption activation energy, shows that the reactivity cannot be explained by the desorption rates of the complexes alone. 6 figs, 4 tabs, 9 refs.

  20. Survey of carbonization facilities for municipal solid waste treatment in Japan.

    Science.gov (United States)

    Hwang, In-Hee; Kawamoto, Katsuya

    2010-07-01

    The operations of carbonization facilities for municipal solid waste treatment in Japan were examined. Input waste, system processes, material flows, quality of char and its utilization, fuel and chemical consumption, control of facility emissions, and trouble areas in facility operation were investigated and analyzed. Although carbonization is a technically available thermochemical conversion method for municipal solid waste treatment, problems of energy efficiency and char utilization must be solved for carbonization to be competitive. Possible solutions include (1) optimizing the composition of input waste, treatment scale, organization of unit processes, operational methods, and quality and yield of char on the basis of analysis and feedback of long-term operating data of present operating facilities and (2) securing stable char demands by linking with local industries such as thermal electric power companies, iron manufacturing plants, and cement production plants. PMID:20149627