WMU Power Generation Study Task 2.0 Corn Cob Co-Combustion Study: Final Report

Energy Technology Data Exchange (ETDEWEB)

Folkedahl, Bruce [Folkedahl Consulting, Inc., Willmar, MN (United States)

2009-12-01

Much attention has been focused on renewable energy use in large-scale utilities and very small scale distributed energy systems. However, there is little information available regarding renewable energy options for midscale municipal utilities. The Willmar Municipal Utilities Corn Cob-Coal Co-Combustion Project was initiated to investigate opportunities available for small to midscale municipal utilities to "go green". The overall goal of the Project was to understand the current renewable energy research and energy efficiency projects that are or have been implemented at both larger and smaller scale and determine the applicability to midscale municipal utilities. More specific objectives for Task 2.0 of this project were to determine the technical feasibility of co-combusting com cobs with coal in the existing WMU boiler, and to identify any regulatory issues that might need to be addressed if WMU were to obtain a significant portion of its heat from such co-combustion. This report addresses the issues as laid out in the study proposal. The study investigated the feasibility of and demonstrated the technical effectiveness of co-combusting corn cobs with coal in the Willmar Municipal Utilities stoker boiler steam generation power plant. The results of the WMU Co-Combustion Project will serve as a model for other midscale utilities who wish to use corn cobs to generate renewable electrical energy. As a result of the Co-Combustion Project, the WMU plans to upgrade their stoker boiler to accept whole corn cobs as well as other types of biomass, while still allowing the fuel delivery system to use 100% coal as needed. Benefits of co-combustion will include: energy security, reduced Hg and CO₂ air emissions, improved ash chemistry, potential future carbon credit sales, an immediate positive effect on the local economy, and positive attention focused on the WMU and the City of Willmar. The first step in the study was to complete a feasibility analysis. The

Experimental research concerning waste co-combustion

Energy Technology Data Exchange (ETDEWEB)

Ionel, I.

2007-07-01

The paper focuses on a lab facility designed for the co-combustion of low calorific Lignite with waste. Also a technology for the potential removal of principal pollutants such as NO{sub x}, Hg and SO{sub 2}, including particles in the fuel gases is described. The novelty of the paper consists in the lay out of the experimental rigs, as well as the application of renewable energy resource in order to generate energy, with lower CO{sub 2} emission. (orig.)

Investigation on the co-combustion of low calorific oil shale and its semi-coke by using thermogravimetric analysis

International Nuclear Information System (INIS)

Yang, Yu; Lu, Xiaofeng; Wang, Quanhai

2017-01-01

Highlights: • The co-combustion characteristic parameters were studied. • The co-combustion of oil shale and semi-coke could be expressed roughly by the addition of individual components. • Activation energy was calculated by Coats-Redfern, distributed activation energy model and Flynn-Wall-Ozawa methods. - Abstract: In the present work, thermogravimetric analysis was employed to investigate co-combustion behaviors of Fushun low calorific oil shale and its semi-coke. The synergy effect was estimated by using the interaction coefficient and the relative error of mean square root. In addition, activation energy was also calculated by means of Coats-Redfern, distributed activation energy model and Flynn-Wall-Ozawa methods. Results indicated that with the increase of oil shale mass fraction and oxygen concentration, combustion characteristics of the samples were improved. And some little interaction did occur during the co-combustion process, but it was relatively slight. Consequently, the co-combustion of oil shale and semi-coke still could be expressed roughly by the addition of individual components of the mixtures. Furthermore, activation energy of the samples decreased slowly at the initial stage attributed to the minerals’ catalytic effects, and in the final stage, it jumped to a high value, suggesting that the burnout of the samples was difficult. Besides, the mix proportion of oil shale which was added to stabilize the combustion in the circulating fluidized bed was also theoretically calculated.

Heavy metals behavior during monocombustion and co-combustion of sewage sludge

Energy Technology Data Exchange (ETDEWEB)

Lopes, M.H.; Abelha, P.; Oliveira, J.F.S.; Cabrita, I.; Gulyurtlu, I. [DEECA, INETI, Lisbon (Portugal)

2005-04-01

This paper presents the study of the combustion of granular dry sewage sludge performed on a pilot fluidized bed system. The results of monocombustion of sludge and co-combustion with coal were compared with those of coal combustion for ash partitioning, the formation of gaseous pollutants, and heavy metals behavior. It was found that the mineral matter of sludge was essentially retained as bottom ash. The production of fine ash was small during the monocombustion but was high during co-combustion due to the tendency of coal to produce fine ash, which also contained unburned char. The degree of heavy metal volatilization was found to be slightly higher during co-combustion than in monocombustion; however, most of the metals were retained in the ash and their emissions were found to be below the regulated levels. Hg was completely volatilized. However, during combustion trials involving coal, Hg was captured in the cyclone ash at temperatures below 300{sup o}C. During sludge monocombustion the retention of Hg in cyclone ash containing low loss on ignition (LOI) was not enough to decrease emissions below the EU regulated levels; hence, it is necessary to install dedicated flue gas treatment for Hg removal. The leachability and ecotoxicity of sludge and ash were also compared with the new regulatory limits for landfill disposal in the European Union (EU).

Present status and perspectives of Co-combustion in German power plants

Energy Technology Data Exchange (ETDEWEB)

Richers, U.; Seifert, H. [Forschungszentrum Karlsruhe GmbH Technik und Umwelt (Germany). Inst. fuer Technische Chemie]|[Forschungszentrum Karlsruhe GmbH Technik und Umwelt (Germany). Programm Nachhaltigkeit, Energie- und Umwelttechnik; Scheurer, W.; Hein, K.R.G. [Stuttgart Univ. (Germany). Inst. fuer Verfahrenstechnik und Dampfkesselwesen

2002-05-01

Various approaches to the future waste management policy in Germany are currently under discussion. One problem arising in this connection is the suitability of existing furnaces for the co-combustion of waste. The use of sewage treatment sludge in power plants is already being practiced on a technical scale. Co-combustion in power plants is of interest also because of the CO{sub 2} problem, as renewable resources can also be used for this purpose. This article documents the technical status of co-combustion in Germany and the available quantities of selected supplementary fuels. Moreover, experience accumulated in German coal fired power plants in using supplementary fuels is compiled. Future possibilities are assessed. (orig.) [German] Fuer die zukuenftige Ausrichtung der Abfallentsorgung gibt es verschiedene Moeglichkeiten, die in der Bundesrepublik Deutschland diskutiert werden. Eine Fragestellung in diesem Zusammenhang ist die Eignung bestehender Feuerungsanlagen fuer die Mitverbrennung von Abfallstoffen. Der Einsatz von Klaerschlamm in Kraftwerken wird bereits grosstechnisch praktiziert. Die Mitverbrennung in Kraftwerken ist zusaetzlich aufgrund der CO{sub 2}-Problematik von Interesse, denn nachwachsende Rohstoffe eignen sich ebenfalls zur Mitverbrennung. In dieser Arbeit werden der technische Stand der Mitverbrennung in der Bundesrepublik Deutschland und die dort zur Verfuegung stehenden Mengen ausgewaehlter Zusatzbrennstoffe dokumentiert. Ausserdem werden die Erfahrungen aus deutschen Kraftwerken beim Einsatz von Zusatzbrennstoffen zusammengestellt. Die zukuenftigen Moeglichkeiten werden abgeschaetzt. (orig.)

Biomass utilization for green environment: Co-combustion of diesel fuel and producer gas in thermal application

International Nuclear Information System (INIS)

Hussain, A.; Ani, F.N.; Mehamed, A.F.

2007-01-01

Study of co-combustion of diesel oil and producer gas from a gasifier, individually as well as combined, in an experimental combustion chamber revealed that the producer gas can be co-combusted with liquid fuel. The process produced more CO, NO/sub x/, SO/sub 2/ and CO/sub 2/ as compared to the combustion of diesel oil alone; the exhaust temperature for the process was higher than the diesel combustion alone. (author)

Characterisation of supplementary fuels for co-combustion with pulverised coal

NARCIS (Netherlands)

Heikkinen, J.M.

2005-01-01

The current and future energy policy aims at increasing the share of renewable energy in worlds energy supply. One possibility to enhance energy production by renewable sources within a short term is co-combustion. This means co-firing biomass and waste with fossil fuels at existing power plants

Co-combustion of peach and apricot stone with coal in a bubbling fluidized bed

Energy Technology Data Exchange (ETDEWEB)

Atimtay, Aysel T.; Kaynak, Burcak [Department of Environmental Engineering, Middle East Technical University, Ankara 06531 (Turkey)

2008-02-15

In this study a bubbling fluidized bed combustor (BFBC) having an inside diameter of 102 mm and a height of 900 mm was used to investigate the co-combustion characteristics of peach and apricot stones produced as a waste from the fruit juice industry with coal. A lignite coal was used for co-combustion. On-line concentrations of O{sub 2}, CO, CO{sub 2}, SO{sub 2}, NO{sub X} and total hydrocarbons (C{sub m}H{sub n}) were measured in the flue gas during combustion experiments. Variations of emissions of various pollutants were studied by changing the operating parameters (excess air ratio, fluidization velocity, and fuel feed rate). Temperature distribution along the bed was measured with thermocouples. For co-combustion of apricot and peach fruit stones with a lignite coal, various ratios of biomass to coal ranging from 0 to 100 wt.% were tested. For the peach stone co-combustion tests, efficiencies are about 98% and for the apricot stone co-combustion tests, efficiencies ranged between 94.7% and 96.9% for 25%, 50% and 75% of apricot stone in the fuel mixture. The results of this study have shown that as the biomass ratio in the fuel mixture increases, the combustion takes place at the upper regions of the main column. This causes higher temperatures in the freeboard than the bed. Also the CO and hydrocarbon (C{sub m}H{sub n}) emissions increase as the biomass percentage increases in the fuel mixture. This causes decrease in the combustion efficiency. These results suggest that peach and apricot stones are potential fuels that can be utilized for clean energy production in small-scale fruit juice industries by using BFBC. The percentage of peach stones or apricot stones in the fuel mixture is suggested to be below 50 wt.% in order to obtain the emission limits of EU. During the design of the BFBC, one has to be careful about the volatile matter (VM) content of the biomass. For the complete combustion of the VM, longer freeboard or secondary air addition should be

Co-combustion of waste materials using fluidized bed technology

Energy Technology Data Exchange (ETDEWEB)

M. Lopes; I. Gulyurtlu; P. Abelha; T. Crujeira; D. Boavida; I. Cabrita [INETI-DEECA, Lisbon (Portugal)

2004-07-01

There is growing interest in using renewable fuels in order to sustain the CO{sub 2} accumulation. Several waste materials can be used as coal substitutes as long as they contain significant combustible matter, as for example MSW and sewage sludge. Besides the outcome of the energetic valorization of such materials, combustion must be regarded as a pre-treatment process, contributing to the safe management of wastes. Landfilling is an expensive management option and requires a previous destruction of the organic matter present in residues, since its degradation generates greenhouse gases and produces acidic organic leachates. Fluidized bed combustion is a promising technology for the use of mixtures of coal and combustible wastes. This paper presents INETI's experience in the co-combustion of coal with this kind of residues performed in a pilot fluidized bed. Both the RDF (from MSW and sewage sludge) and sewage sludge combustion problems were addressed, relating the gaseous emissions, the behaviour of metals and the leachability of ashes and a comparison was made between co-combustion and mono-combustion in order to verify the influence of the utilization of coal. 9 refs., 1 fig., 3 tabs.

Combustion and co-combustion of biomass in a bubbling fluidized bed boiler

NARCIS (Netherlands)

Khan, A.A.

2007-01-01

This PhD dissertation concerns the study of different aspects of biomass (co)-combustion in small-scale fluidized bed boilers for heat generation. The most renowned gaseous emissions from fluidized bed combustion, namely, CO and NO, are investigated with the help of experimental and theoretical

Use of nitrogen stable isotope analysis to understand char nitrogen evolution during the fluidized-bed co-combustion of coal and sewage sludge

Energy Technology Data Exchange (ETDEWEB)

Ana Arenillas; Roberto Garcia; Chenggong Sun; Colin E. Snape; Angel H. Moreno; Fernando Rubiera; Jose J. Pis [University of Nottingham, Nottingham (United Kingdom). Nottingham Fuel and Energy Centre, School of Chemical, Environmental and Mining Engineering

2005-04-01

NOx emissions from sewage sludge combustion are a concern, because of the usually high nitrogen content of this fuel. The interactions during co-combustion in a fluidized-bed reactor of sewage sludge and a bituminous coal were evaluated, in relation to the nitrogen evolution during the combustion process. The nitrogen stable isotope measurements provide novel results regarding the tracing of nitrogen during combustion. Our preliminary results show that the co-combustion chars retain more nitrogen than expected, with the additional nitrogen being mainly derived from the sludge. Additional measurements are planned on the resultant co-combustion gases, to aid source apportionment of the NOx arising from coal/sewage interactions. 14 refs., 3 figs., 2 tabs.

Co-combustion of household waste in small-scale energy supply and waste disposal plants; Co-Verbrennung von Siedlungsabfaellen in Kleinanlagen zur dezentralen Energieversorgung und Abfallentsorgung

Energy Technology Data Exchange (ETDEWEB)

Schroeer, Ramona

2012-07-01

The studies described in this book demonstrate that the co-combustion of household waste in small-scale combustion plants constitutes an alternative disposal concept which facilitates the operation of decentralised waste disposal and heat supply systems. The basic idea of the concept is the co-combustion of different waste fractions in common household logwood heating systems. The experiments performed have shown that this is technically feasible using currently available technology without further modification and that these plants are capable of combusting various waste fractions at low emission levels. Several co-combustion systems were compared with basic oil, pellet and logwood heating systems in both economic and ecological respects. For this purpose cost-effectiveness calculations and a life cycle assessment were performed and brought together in an eco-efficiency analysis. The results show that the most cost-effective and eco-efficient solution is achieved when the co-combustion system is operated for high energy yield and simultaneous reduction of incombustible fractions.

Model Research of Gas Emissions From Lignite and Biomass Co-Combustion in a Large Scale CFB Boiler

Directory of Open Access Journals (Sweden)

Krzywański Jarosław

2014-06-01

Full Text Available The paper is focused on the idea of a combustion modelling of a large-scale circulating fluidised bed boiler (CFB during coal and biomass co-combustion. Numerical computation results for three solid biomass fuels co-combustion with lignite are presented in the paper. The results of the calculation showed that in previously established kinetics equations for coal combustion, some reactions had to be modified as the combustion conditions changed with the fuel blend composition. Obtained CO2, CO, SO2 and NOx emissions are located in borders of ± 20% in the relationship to the experimental data. Experimental data was obtained for forest biomass, sunflower husk, willow and lignite cocombustion tests carried out on the atmospheric 261 MWe COMPACT CFB boiler operated in PGE Turow Power Station in Poland. The energy fraction of biomass in fuel blend was: 7%wt, 10%wt and 15%wt. The measured emissions of CO, SO2 and NOx (i.e. NO + NO2 were also shown in the paper. For all types of biomass added to the fuel blends the emission of the gaseous pollutants was lower than that for coal combustion.

Incineration and co-combustion of waste: accounting of greenhouse gases and global warming contributions

DEFF Research Database (Denmark)

Astrup, Thomas; Møller, Jacob; Fruergaard, Thilde

2009-01-01

Important greenhouse gas (GHG) emissions related to waste incineration and co-combustion of waste were identified and considered relative to critical aspects such as: the contents of biogenic and fossil carbon, N2O emissions, fuel and material consumptions at the plants, energy recovery, and soli...

The effect of biomass on pollutant emission and burnout in co-combustion with coal

Energy Technology Data Exchange (ETDEWEB)

Kruczek, H.; Raczka, P.; Tatarek, A. [Wroclaw Technical University, Wroclaw (Poland)

2006-08-15

This paper presents experimental and numerical results on the co-combustion of different types of biomass with hard and brown coal. The main aim of this work was to assess the impact of the cocombustion of biomass in brown and hard coal-fired systems on the combustion process itself and on the level of pollutant formation and its dependence on combustion temperature stoichiometry. The experimental results obtained have shown that in general biomass addition leads to decreased NO and SO{sub 2} emissions, except with the hard coal Bogdanka. In addition, the biomass has a beneficial effect on the burnout of the coal/biomass mixture. To help to account for this effect, the behaviour of coal and biomass, the coal/biomass mixture and of fuel-N was studied by thermal analysis, in nitrogen and in air. The results obtained have shown that gas phase interactions are dominant in the combustion of biomass/coal mixtures.

The impact of co-combustion of polyethylene plastics and wood in a small residential boiler on emissions of gaseous pollutants, particulate matter, PAHs and 1,3,5- triphenylbenzene.

Science.gov (United States)

Tomsej, Tomas; Horak, Jiri; Tomsejova, Sarka; Krpec, Kamil; Klanova, Jana; Dej, Milan; Hopan, Frantisek

2018-04-01

The aim of this study was to simulate a banned but widely spread practice of co-combustion of plastic with wood in a small residential boiler and to quantify its impact on emissions of gaseous pollutants, particulate matter (PM), polycyclic aromatic hydrocarbons (PAHs), and 1,3,5-triphenylbenzene (135TPB), a new tracer of polyethylene plastic combustion. Supermarket polyethylene shopping bags (PE) and polyethylene terephthalate bottles (PET) were burnt as supplementary fuels with beech logs (BL) in an old-type 20 kW over-fire boiler both at a nominal and reduced heat output. An impact of co-combustion was more pronounced at the nominal heat output: an increase in emissions of PM, total organic carbon (TOC), toxic equivalent (TEQ) of 7 carcinogenic PAHs (c-PAHs) and a higher ratio of c-PAHs TEQ in particulate phase was observed during co-combustion of both plastics. 135TPB was found in emissions from both plastics both at a nominal and reduced output. In contrast to findings reported in the literature, 135TPB was a dominant compound detected by mass spectrometry on m/z 306 exclusively in emissions from co-combustion of PE. Surprisingly, six other even more abundant compounds of unknown identity were found on this m/z in emissions from co-combustion of PET. One of these unknown compounds was identified as p-quaterphenyl (pQ). Principal component analysis revealed strong correlation among 135TPB, pQ and five unknown compounds. pQ seems to be suitable tracers of polyethylene terephthalate plastic co-combustion, while 135TPB proved its suitability to be an all-purpose tracer of polyethylene plastics combustion. Copyright © 2017 Elsevier Ltd. All rights reserved.

Comparative study of two co-combustion concepts for sewage sludge in coal dust furnaces; Vergleich zweier Mitverbrennungskonzepte fuer Klaerschlamm in Kohlestaubfeuerungen

Energy Technology Data Exchange (ETDEWEB)

Spliethoff, H; Gerhardt, T; Ruediger, H; Hein, K R.G. [Stuttgart Univ. (Germany). Inst. fuer Verfahrenstechnik und Dampfkesselwesen

1997-12-31

Processes for thermal use of sewage sludge in coal dust furnaces were investigated at the Institute of Chemical Engineering and Boiler Technology (IVD) of Stuttgart university. Direct co-combustion of sewage sludge in coal dust furnaces is a simple concept, but it is useful provided that co-combustion has no negative effects in terms of performance, emissions and residue disposal. Externally dried sewage sludge has a residual water content in the same range as coal dust. The effects of co-combustion are discussed, and the experimentally determined effect in terms of emissions and residues is presented. Pyrolysis of the sewage sludge and use of the resulting gas as a reduction agent for denitrification may reduce negative effects of co-combustion on performance, emissions and residues.(orig) [Deutsch] Am Institut fuer Verfahrenstechnik und Dampfkesselwesen (IVD) der Universitaet Stuttgart werden an Versuchsanlagen verschiedene Verfahren zur thermischen Nutzung von Klaerschlaemmen in Verbindung mit Kohlenstaufeuerungen untersucht. Die direkte Mitverbrennung von Klaerschlamm in Kohlestaubfeuerungen ist ein einfaches Konzept, das dann sinnvoll ist, wenn die Mitverbrennung keine negativen Auswirkungen auf Betrieb, Emissionen und Verwertung der Rueckstaende mit sich bringt. Bei einer externen Trockung weist der Klaerschlamm einen aehnlichen Wassergehalt wie der Auslegungsbrennstoff von Steinkohlenstaubfeuerungen auf. Die moeglichen Auswirkungen der Mitverbrennung von Klaerschlamm werden diskutiert und der im Versuch ermittelte Einfluss auf Emissionen und Reststoffe vogestellt. Durch Vorschaltung einer Pyrolyse des Klaerschlamms und Nutzung des erzeugten Gases als Reduktionsmittel zur Entsticklung kann die Auswirkung der Mitverbrennung auf Betrieb, Emissionen und Reststoffe der Feuerungsanlage vermindert werden. (orig)

Comparative study of two co-combustion concepts for sewage sludge in coal dust furnaces; Vergleich zweier Mitverbrennungskonzepte fuer Klaerschlamm in Kohlestaubfeuerungen

Energy Technology Data Exchange (ETDEWEB)

Spliethoff, H.; Gerhardt, T.; Ruediger, H.; Hein, K.R.G. [Stuttgart Univ. (Germany). Inst. fuer Verfahrenstechnik und Dampfkesselwesen

1996-12-31

Processes for thermal use of sewage sludge in coal dust furnaces were investigated at the Institute of Chemical Engineering and Boiler Technology (IVD) of Stuttgart university. Direct co-combustion of sewage sludge in coal dust furnaces is a simple concept, but it is useful provided that co-combustion has no negative effects in terms of performance, emissions and residue disposal. Externally dried sewage sludge has a residual water content in the same range as coal dust. The effects of co-combustion are discussed, and the experimentally determined effect in terms of emissions and residues is presented. Pyrolysis of the sewage sludge and use of the resulting gas as a reduction agent for denitrification may reduce negative effects of co-combustion on performance, emissions and residues.(orig) [Deutsch] Am Institut fuer Verfahrenstechnik und Dampfkesselwesen (IVD) der Universitaet Stuttgart werden an Versuchsanlagen verschiedene Verfahren zur thermischen Nutzung von Klaerschlaemmen in Verbindung mit Kohlenstaufeuerungen untersucht. Die direkte Mitverbrennung von Klaerschlamm in Kohlestaubfeuerungen ist ein einfaches Konzept, das dann sinnvoll ist, wenn die Mitverbrennung keine negativen Auswirkungen auf Betrieb, Emissionen und Verwertung der Rueckstaende mit sich bringt. Bei einer externen Trockung weist der Klaerschlamm einen aehnlichen Wassergehalt wie der Auslegungsbrennstoff von Steinkohlenstaubfeuerungen auf. Die moeglichen Auswirkungen der Mitverbrennung von Klaerschlamm werden diskutiert und der im Versuch ermittelte Einfluss auf Emissionen und Reststoffe vogestellt. Durch Vorschaltung einer Pyrolyse des Klaerschlamms und Nutzung des erzeugten Gases als Reduktionsmittel zur Entsticklung kann die Auswirkung der Mitverbrennung auf Betrieb, Emissionen und Reststoffe der Feuerungsanlage vermindert werden. (orig)

Characterisation of ashes produced by co-combustion of recovered fuels and peat

Energy Technology Data Exchange (ETDEWEB)

Frankenhaeuser, M.; Zevenhoven, R. [Borealis Polymers Oy, Porvoo (Finland); Skrifvars, B.J. [Aabo Akademi, Turku (Finland); Orjala, M. [VTT Energy, Espoo (Finland); Peltola, K. [Foster Wheeler Energy (Finland)

1996-12-01

Source separation of combustible materials from household or municipal solid waste yields a raw material for the production of Packaging Derived Fuel (PDF). This fuel can substitute the traditional fuels in heat and power generation and is also called recycled fuel. Co-combustion of these types of fuels with coal has been studied in several LIEKKI-projects and the results have been both technically and environmentally favourable. (author)

Co-Combustion of Municipal Sewage Sludge and Hard Coal on Fluidized Bed Boiler WF-6

Directory of Open Access Journals (Sweden)

Rajczyk Rafał

2014-12-01

Full Text Available According to data of the Central Statistical Office, the amount of sludge produced in municipal wastewater treatment plants in 2010 amounted to 526000 Mg d.m. The forecast of municipal sewage sludge amount in 2015 according to KPGO2014 will reach 642400 Mg d.m. and is expected to increase in subsequent years. Significant amounts of sludge will create problems due to its utilization. In order to solve this problem the use of thermal methods for sludge utilization is expected. According to the National Waste Management Plan nearly 30% of sewage sludge mass should be thermally utilized by 2022. The article presents the results of co-combustion of coal and municipal sewage sludge in a bubbling fluidized bed boiler made by SEFAKO and located in the Municipal Heating Company in Morag. Four tests of hard coal and sewage sludge co-combustion have been conducted. Boiler performance, emissions and ash quality were investigated.

Electricity generation from solid biomass via co-combustion with coal. Energy and emission balances from a German case study

International Nuclear Information System (INIS)

Hartmann, D.; Kaltschmitt, M.

1999-01-01

The environmental effects of electricity production from different biofuels by means of co-combustion with hard coal in existing coal fired power plants are analysed and compared to electricity production from hard coal alone based on Life Cycle Analysis (LCA). The use of straw and residual wood at a 10% blend with coal in an existing power plant in the southern part of Germany shows that all investigated environmental effects are significantly lower if biomass is used instead of coal. Thus based on the available and proven technology of co-combustion of hard coal and biomass in existing power plants a significant contribution could be made to a more environmentally sound energy system compared to using coal alone. (author)

Co-combustion of low rank coal/waste biomass blends using dry air or oxygen

International Nuclear Information System (INIS)

Haykiri-Acma, H.; Yaman, S.; Kucukbayrak, S.

2013-01-01

Biomass species such as the rice husk and the olive milling residue, and a low quality Turkish coal, Soma Denis lignite, were burned in a thermal analyzer under pure oxygen and dry air up to 900 °C, and differential thermal analysis (DTA) and derivative thermogravimetric (DTG) analysis profiles were obtained. Co-combustion experiments of lignite/biomass blends containing 5–20 wt% of biomass were also performed. The effects of the oxidizer type and the blending ratio of biomass were evaluated considering some thermal reactivity indicators such as the maximum burning rate and its temperature, the maximum heat flow temperature, and the burnout levels. FTIR (Fourier transform infrared) spectroscopy and SEM (scanning electron microscopy) were used to characterize the samples, and the variations in the combustion characteristics of the samples were interpreted based on the differences in the intrinsic properties of the samples. - Highlights: ► Co-combustion of lignite/biomass blends. ► The effects of the oxidizer type and the blending ratio. ► Effects of intrinsic properties on combustion characteristics.

Cocombustion of secondary fuels with Rhenish brown coal; Mitverbrennung von Sekundaerbrennstoffen mit rheinischer Braunkohle

Energy Technology Data Exchange (ETDEWEB)

Gerhardt, Alexander; Kull, Rene; Zepf, Eva; Fuller, Aaron; Maier, Joerg; Scheffknecht, Guenter [Stuttgart Univ. (Germany). Inst. fuer Verfahrenstechnik und Dampfkesselwesen; Jong, Martin de [KEMA Nederland B.V. (Netherlands); Glorius, Thomas [REMONDIS Trade and Sales GmbH (Germany)

2008-07-01

The Institute of Combustion and Power Plant of Technology of the University of Stuttgart (Stuttgart, Federal Republic of Germany) performs scientific research within the range of solid firings. The cocombustion of secondary fuels in coal-fired power stations as well as the production of secondary fuels are examined in the project RECOFUEL. The production of secondary fuels is performed from harmless house wastes and commercial wastes as well as from biological residues from forestry and agriculture. Secondary fuels offer an alternative to fossil fuels for the power production in different branches of industry and reduce the emission of carbon dioxide from fossil sources. For the attempts in two power stations of RWE Power AG (Essen, Federal Republic of Germany) the quality-certified secondary fuel SBS1 registered of the company Remondis GmbH (Luenen, Federal Republic of Germany) was used. This secondary fuel was developed and subjected to an intensive analysis. Experiments in a pulverized fuel furnace and in a fluidised bed were performed at the power stations Weisweiler and Berrenrath in order to examine different aspects of the cocombustion.

Characteristics of carbonized sludge for co-combustion in pulverized coal power plants

International Nuclear Information System (INIS)

Park, Sang-Woo; Jang, Cheol-Hyeon

2011-01-01

Co-combustion of sewage sludge can destabilize its combustion profile due to high volatility, which results in unstable flame. We carried out fuel reforming for sewage sludge by way of carbonization at pyrolysis temperature of 300-500 deg. C. Fuel characteristics of carbonized sludge at each temperature were analyzed. As carbonization temperature increased, fuel ratio increased, volatile content reduced, and atomic ratio relation of H/C and O/C was similar to that of lignite. The analysis result of FT-IR showed the decrease of aliphatic C-H bond and O-C bond in carbonization. In the analysis result of TG-DTG, the thermogravimetry reduction temperature of carbonized sludge (CS400) was proven to be higher than that of dried sludge, but lower than that of sub-bituminous coal. Hardgrove grindability index increased in proportion to fuel ratio increase, where the carbonized sludge value of 43-110 was similar or higher than the coal value of 49-63. As for ash deposits, slagging and fouling index were higher than that of coal. When carbonized sludge (CS400) and coal were co-combusted in 1-10% according to calorific value, slagging tendency was low in all conditions, and fouling tendency was medium or high according to the compositions of coal.

Co-combustion of cultivable raw materials in existing power supply plants -a study on the potential for such plants in the eastern Laender. Final report

International Nuclear Information System (INIS)

Grosskopf, W.; Kappelmann, K.H.

1996-04-01

The present study is dedicated to an analysis of co-combustion of biomass in existing power supply plants in the eastern Laender. The question to be resolved is whether the existing substantial potential for substituting fossil energy carriers for biomass in the short term and at low cost also offers a viable option from the viewpoint of political economy. In its final assessment the study also takes agropolitical and ecopolitical interests into account. A further basic question posed by this impact analysis is in what way the increased use of biomass as an energy carrier can contribute to farmers; income and thus help improve employment in rural area. Implicated in this is the question whether the conservation of developed land resulting from large-area biomass cultivation is desirable from the sociopolitical viewpoint. Another important aspect concerning the impact analysis is the question as to the environmental efficiency of biomass co-combustion given the Federal Government's aims regarding CO 2 abatement. The study examines how biomas co-combustion compares with other alternatives to this end in terms of CO 2 abatement costs. These deliberations provide the basis for the study's concluding recommendations to political decision makers who are confronted with the question whether and under what conditions public promotion of biomass co-combustion in the new Laender makes sociopolitical sense. (orig./SR) [de

Combustion characteristics and air pollutant formation during oxy-fuel co-combustion of microalgae and lignite.

Science.gov (United States)

Gao, Yuan; Tahmasebi, Arash; Dou, Jinxiao; Yu, Jianglong

2016-05-01

Oxy-fuel combustion of solid fuels is seen as one of the key technologies for carbon capture to reduce greenhouse gas emissions. The combustion characteristics of lignite coal, Chlorella vulgaris microalgae, and their blends under O2/N2 and O2/CO2 conditions were studied using a Thermogravimetric Analyzer-Mass Spectroscopy (TG-MS). During co-combustion of blends, three distinct peaks were observed and were attributed to C. vulgaris volatiles combustion, combustion of lignite, and combustion of microalgae char. Activation energy during combustion was calculated using iso-conventional method. Increasing the microalgae content in the blend resulted in an increase in activation energy for the blends combustion. The emissions of S- and N-species during blend fuel combustion were also investigated. The addition of microalgae to lignite during air combustion resulted in lower CO2, CO, and NO2 yields but enhanced NO, COS, and SO2 formation. During oxy-fuel co-combustion, the addition of microalgae to lignite enhanced the formation of gaseous species. Copyright © 2016 Elsevier Ltd. All rights reserved.

Characteristics of carbonized sludge for co-combustion in pulverized coal power plants.

Science.gov (United States)

Park, Sang-Woo; Jang, Cheol-Hyeon

2011-03-01

Co-combustion of sewage sludge can destabilize its combustion profile due to high volatility, which results in unstable flame. We carried out fuel reforming for sewage sludge by way of carbonization at pyrolysis temperature of 300-500°C. Fuel characteristics of carbonized sludge at each temperature were analyzed. As carbonization temperature increased, fuel ratio increased, volatile content reduced, and atomic ratio relation of H/C and O/C was similar to that of lignite. The analysis result of FT-IR showed the decrease of aliphatic C-H bond and O-C bond in carbonization. In the analysis result of TG-DTG, the thermogravimetry reduction temperature of carbonized sludge (CS400) was proven to be higher than that of dried sludge, but lower than that of sub-bituminous coal. Hardgrove grindability index increased in proportion to fuel ratio increase, where the carbonized sludge value of 43-110 was similar or higher than the coal value of 49-63. As for ash deposits, slagging and fouling index were higher than that of coal. When carbonized sludge (CS400) and coal were co-combusted in 1-10% according to calorific value, slagging tendency was low in all conditions, and fouling tendency was medium or high according to the compositions of coal. Copyright © 2010 Elsevier Ltd. All rights reserved.

Co-Combustion of Animal Waste in a Commercial Waste-to-Energy BFB Boiler

Directory of Open Access Journals (Sweden)

Farzad Moradian

2013-11-01

Full Text Available Co-combustion of animal waste, in waste-to-energy boilers, is considered a method to produce both heat and power and to dispose of possibly infected animal wastes. This research conducted full-scale combustion tests to identify the impact of changed fuel composition on a fluidized-bed boiler. The impact was characterized by analyzing the deposit formation rate, deposit composition, ash composition, and emissions. Two combustion tests, denoted the reference case and animal waste case, were performed based on different fuel mixes. In the reference case, a normal solid waste fuel mix was combusted in the boiler, containing sorted industry and household waste. In the animal waste case, 20 wt% animal waste was added to the reference fuel mix. The collected samples, comprising sampling probe deposits, fuel mixes, bed ash, return sand, boiler ash, cyclone ash and filter ash, were analyzed using chemical fractionation, SEM-EDX and XRD. The results indicate decreased deposit formation due to animal waste co-combustion. SEM-EDX and chemical fractionation identified higher concentrations of P, Ca, S, and Cl in the bed materials in the animal waste case. Moreover, the risk of bed agglomeration was lower in the animal waste case and also a decreased rate of NOx and SO2 emissions were observed.

Co-combustion of waste with coal in a circulating fluidised bed combustor

Energy Technology Data Exchange (ETDEWEB)

Gulyurtlu, I.; Boavida, D.; Abelha, P.; Lopes, H.; Cabrita, I. [DEECA-INETI, Lisboa (Portugal)

2002-07-01

The results of a study of cocombustion of waste with coal is described. Various wastes (biomass, sludge, and refuse derived fuel) were burned with coal in a circulating fluidised bed combustor. Conditions that prevent segregated combustion, reduce production of nitrogen oxides, and attain high combustion efficiency were studied. The effects of variations in air staging in the riser, mixing of air with volatiles, coal/biomass ratio, methods of feeding biomass, and temperature are described. 5 refs., 3 figs., 5 tabs.

Co-combustion of anthracite coal and wood pellets: Thermodynamic analysis, combustion efficiency, pollutant emissions and ash slagging.

Science.gov (United States)

Guo, Feihong; Zhong, Zhaoping

2018-08-01

This work presents studies on the co-combustion of anthracite coal and wood pellets in fluidized bed. Prior to the fluidized bed combustion, thermogravimetric analysis are performed to investigate the thermodynamic behavior of coal and wood pellets. The results show that the thermal decomposition of blends is divided into four stages. The co-firing of coal and wood pellets can promote the combustion reaction and reduce the emission of gaseous pollutants, such as SO 2 and NO. It is important to choose the proportion of wood pellets during co-combustion due to the low combustion efficiency caused by large pellets with poor fluidization. Wood pellets can inhibit the volatilization of trace elements, especially for Cr, Ni and V. In addition, the slagging ratio of wood pellets ash is reduced by co-firing with coal. The research on combustion of coal and wood pellets is of great significance in engineering. Copyright © 2018 Elsevier Ltd. All rights reserved.

Energy and emission aspects of co-combustion solid recovered fuel with coal in a stoker boiler

Science.gov (United States)

Wasielewski, Ryszard; Głód, Krzysztof; Telenga-Kopyczyńska, Jolanta

2018-01-01

The results of industrial research on co-combustion of solid recovered fuel (SRF) with hard coal in a stoker boiler type WR-25 has been presented. The share of SRF in the fuel mixture was 10%. During the co-combustion of SRF, no technological disturbances or significant reduction in energy efficiency of the boiler were noted. Obtained SO2, NOx and CO emissions were comparable with coal combustion but dust emissions increased. During combustion of the coal mixture with a 10% share of SRF in the test boiler WR-25, the emission standards established for the combustion of the dedicated fuel were met. However, comparison of obtained emission results with the emission standards established for co-incineration of waste, revealed the exceedance of permissible levels of HCl, dust, heavy metals, dioxins and furans. Additionally, the residence time of flue gases in over 850°C conditions for the test boiler WR-25 was too short (1.3 seconds) in refer to the legislative requirements (2 seconds) for the thermal conversion of waste.

Energy and emission aspects of co-combustion solid recovered fuel with coal in a stoker boiler

Directory of Open Access Journals (Sweden)

Wasielewski Ryszard

2018-01-01

Full Text Available The results of industrial research on co-combustion of solid recovered fuel (SRF with hard coal in a stoker boiler type WR-25 has been presented. The share of SRF in the fuel mixture was 10%. During the co-combustion of SRF, no technological disturbances or significant reduction in energy efficiency of the boiler were noted. Obtained SO2, NOx and CO emissions were comparable with coal combustion but dust emissions increased. During combustion of the coal mixture with a 10% share of SRF in the test boiler WR-25, the emission standards established for the combustion of the dedicated fuel were met. However, comparison of obtained emission results with the emission standards established for co-incineration of waste, revealed the exceedance of permissible levels of HCl, dust, heavy metals, dioxins and furans. Additionally, the residence time of flue gases in over 850°C conditions for the test boiler WR-25 was too short (1.3 seconds in refer to the legislative requirements (2 seconds for the thermal conversion of waste.

Co-combustion of peanut hull and coal blends: Artificial neural networks modeling, particle swarm optimization and Monte Carlo simulation.

Science.gov (United States)

Buyukada, Musa

2016-09-01

Co-combustion of coal and peanut hull (PH) were investigated using artificial neural networks (ANN), particle swarm optimization, and Monte Carlo simulation as a function of blend ratio, heating rate, and temperature. The best prediction was reached by ANN61 multi-layer perception model with a R(2) of 0.99994. Blend ratio of 90 to 10 (PH to coal, wt%), temperature of 305°C, and heating rate of 49°Cmin(-1) were determined as the optimum input values and yield of 87.4% was obtained under PSO optimized conditions. The validation experiments resulted in yields of 87.5%±0.2 after three replications. Monte Carlo simulations were used for the probabilistic assessments of stochastic variability and uncertainty associated with explanatory variables of co-combustion process. Copyright © 2016 Elsevier Ltd. All rights reserved.

Comparative thermogravimetric analyses of co-combustion of textile dyeing sludge and sugarcane bagasse in carbon dioxide/oxygen and nitrogen/oxygen atmospheres: Thermal conversion characteristics, kinetics, and thermodynamics.

Science.gov (United States)

Xie, Wenhao; Wen, Shaoting; Liu, Jingyong; Xie, Wuming; Kuo, Jiahong; Lu, Xingwen; Sun, Shuiyu; Chang, Kenlin; Buyukada, Musa; Evrendilek, Fatih

2018-05-01

Thermodynamic and kinetic parameters of co-combustion of textile dyeing sludge (TDS) and sugarcane bagasse (SB) were studied using thermogravimetric analysis in CO 2 /O 2 and N 2 /O 2 atmospheres. Our results showed that the comprehensive combustion characteristic index (CCI) of the blends was improved by 1.71-4.32 times. With the increased O 2 concentration, co-combustion peak temperature decreased from 329.7 to 318.2 °C, with an increase in its maximum weight loss rate from 10.04 to 14.99%/min and its CCI by 1.31 times (β = 20 °C·min -1 ). To evaluate the co-combustion characteristics, thermodynamic and kinetic parameters (entropy, Gibbs free energy and enthalpy changes, and apparent activation energy) were obtained in the five atmospheres. The lowest apparent activation energy of the TB64 blend was obtained in oxy-fuel atmosphere (CO 2 /O 2  = 7/3). Copyright © 2018 Elsevier Ltd. All rights reserved.

Renew, reduce or become more efficient? The climate contribution of biomass co-combustion in a coal-fired power plant

NARCIS (Netherlands)

Miedema, Jan H.; Benders, Rene M. J.; Moll, Henri C.; Pierie, Frank

2017-01-01

Within this paper, biomass supply chains, with different shares of biomass co-combustion in coal fired power plants, are analysed on energy efficiency, energy consumption, renewable energy production, and greenhouse gas (GHG) emissions and compared with the performance of a 100% coal supply chain

Effect of co-combustion on the burnout of lignite/biomass blends: a Turkish case study.

Science.gov (United States)

Haykiri-Acma, H; Yaman, S

2008-11-01

Co-combustion of Turkish Elbistan lignite and woody shells of hazelnut was performed in a TGA up to 1173 K with a heating rate of 20 K/min. SEM images of each fuel revealed the differences in their physical appearances. Hazelnut shell was blended with lignite in the range of 2-20 wt% to observe the co-combustion properties. Maximum burning rates (Rmax), temperatures of the maximum burning rates (T(R-max)), and the final burnout values of the parent samples and the blends were compared. The results were interpreted considering lignite properties and the major biomass ingredients such as cellulosics, hemicellulosics, and lignin. Deviations between the theoretical and experimental burnout values were evaluated at various temperatures. Burnout characteristics of the blends up to 10 wt% were concluded to have a synergistic effect so the addition of hazelnut shell up to 8 wt% provided higher burnouts than the expected theoretical ones, whereas addition of as much as 10 wt% led to a decrease in the burnout. However, the additive effects were more favorable for the blend having a biomass content of 20 wt%. Apparent activation energy, Rmax, and T(R-max), were found to follow the additive behavior for the blend samples.

Effect of co-combustion on the burnout of lignite/biomass blends: A Turkish case study

Energy Technology Data Exchange (ETDEWEB)

Haykirl-Acma, H.; Yaman, S. [Istanbul Technical University, Istanbul (Turkey)

2008-11-15

Co-combustion of Turkish Elbistan lignite and woody shells of hazelnut was performed in a TGA tip to 1173 K with a heating rate of 20 K/min. SEM images of each fuel revealed the differences in their physical appearances. Hazelnut shell was blended with lignite in the range of 2-20 wt% to observe the co-combustion properties. Maximum burning rates (R{sub max}), temperatures of the maximum burning rates (TR{sub max}), and the final burnout values of the parent samples and the blends were compared. The results were interpreted considering lignite properties and the major biomass ingredients such as cellulosics, hemicellulosics, and lignin. Deviations between the theoretical and experimental burnout values were evaluated at various temperatures. Burnout characteristics of the blends up to 10 wt% were concluded to have a synergistic effect so the addition of hazelnut shell up to 8 wt% provided higher burnouts than the expected theoretical ones, whereas addition of as much as 10 wt% led to a decrease in the burnout. However, the additive effects were more favorable for the blend having a biomass content of 20 wt%. Apparent activation energy, R{sub max} and TR{sub max}, were found to follow the additive behavior for the blend samples.

Co-combustion of sewage sludge; Mitverbrennung von Klaerschlamm

Energy Technology Data Exchange (ETDEWEB)

Thome-Kozmiensky, K.J. [Technische Univ. Berlin (Germany). Fachgebiet Abfallwirtschaft

1998-09-01

Thermal sewage disposal pursues the following aims: destruction of organic pollutants contained in the sludge; concentration and removal or almost complete fixation of inorganic pollutants in the residue matrix; minimisation of the mass solid residue; production of useful products; utilisation of the caloric content. The thermal treatment chain should be as short as possible; intermediate stages in separate reactors such as digestion, drying, degasification or gasification should be avoided if the material is ultimately to be combusted. The present paper examines and assesses the co-combustion of sewage sludge. [Deutsch] Mit der thermischen Klaerschlammentsorgung werden folgende Ziele verfolgt: - Zerstoerung der im Schlamm enthaltenen organischen Schadstoffe, - Konzentration und Ausschleusung oder weitestgehende Fixierung der anorganischen Schadstoffe in die Reststoffmatrix, - Minimierung der Masse an festen Restabfaellen, - Herstellung verwertbarer Produkte, - Nutzung des Waermeeinhalts. Die thermische Behandlungskette sollte moeglichst kurz sein; Zwischenschritte wie Faulung, Trocknung, Ent- oder Vergasung in getrennten Reaktoren sollten vermieden werden, wenn letztendlich doch verbrannt wird. Das Verfahren der Mitverbrennung von Klaerschlamm wird hier untersucht und bewertet. (orig./SR)

Rheology of fly ashes from coal and biomass co-combustion

DEFF Research Database (Denmark)

Arvelakis, Stelios; Frandsen, Flemming

2010-01-01

The presence of large amounts of alkali metals, chlorine and sulphur in most biomass fuels - compared to coal - can create serious ash-related problems such as deposition, agglomeration and/or corrosion. This paper discusses the viscosity characteristics of fly ash from the co-combustion of various...... coal/biomass blends in a pilot scale pf-boiler. The produced data provide information on the melting of the ash and its flow characteristics, as a function of temperature, which may be used to modify the temperature profile of the boiler in order to avoid slagging. Straw co-firing lowers the ash...... viscosity leading to higher stickiness of the ash particles. Wood co-firing has only minor effects, due to the composition of wood ash and the low percentage of wood in the coal/biomass blend....

Comparative Study of Coal and Biomass Co-Combustion With Coal Burning Separately Through Emissions Analysis

OpenAIRE

Mohammad Siddique; Suhail Ahmed Soomro; Aziza Aftab; Zahid Naeem Qaisrani; Abdul Sattar Jatoi; Asadullah; Ghulamullah Khan; Ehsanullah Kakar

2016-01-01

Appropriate eco-friendly methods to mitigate the problem of emissions from combustion of fossil fuel are highly demanded. The current study was focused on the effect of using coal & coal-biomass co-combustion on the gaseous emissions. Different biomass' were used along with coal. The coal used was lignite coal and the biomass' were tree waste, cow dung and banana tree leaves. Various ratios of coal and biomass were used to investigate the combustion behavior of coal-biomass blends and their ...

Emissions from small-scale energy production using co-combustion of biofuel and the dry fraction of household waste.

Science.gov (United States)

Hedman, Björn; Burvall, Jan; Nilsson, Calle; Marklund, Stellan

2005-01-01

In sparsely populated rural areas, recycling of household waste might not always be the most environmentally advantageous solution due to the total amount of transport involved. In this study, an alternative approach to recycling has been tested using efficient small-scale biofuel boilers for co-combustion of biofuel and high-energy waste. The dry combustible fraction of source-sorted household waste was mixed with the energy crop reed canary-grass (Phalaris Arundinacea L.), and combusted in both a 5-kW pilot scale reactor and a biofuel boiler with 140-180 kW output capacity, in the form of pellets and briquettes, respectively. The chlorine content of the waste fraction was 0.2%, most of which originated from plastics. The HCl emissions exceeded levels stipulated in new EU-directives, but levels of equal magnitude were also generated from combustion of the pure biofuel. Addition of waste to the biofuel did not give any apparent increase in emissions of organic compounds. Dioxin levels were close to stipulated limits. With further refinement of combustion equipment, small-scale co-combustion systems have the potential to comply with emission regulations.

Emissions from small-scale energy production using co-combustion of biofuel and the dry fraction of household waste

International Nuclear Information System (INIS)

Hedman, Bjoern; Burvall, Jan; Nilsson, Calle; Marklund, Stellan

2005-01-01

In sparsely populated rural areas, recycling of household waste might not always be the most environmentally advantageous solution due to the total amount of transport involved. In this study, an alternative approach to recycling has been tested using efficient small-scale biofuel boilers for co-combustion of biofuel and high-energy waste. The dry combustible fraction of source-sorted household waste was mixed with the energy crop reed canary-grass (Phalaris Arundinacea L.), and combusted in both a 5-kW pilot scale reactor and a biofuel boiler with 140-180 kW output capacity, in the form of pellets and briquettes, respectively. The chlorine content of the waste fraction was 0.2%, most of which originated from plastics. The HCl emissions exceeded levels stipulated in new EU-directives, but levels of equal magnitude were also generated from combustion of the pure biofuel. Addition of waste to the biofuel did not give any apparent increase in emissions of organic compounds. Dioxin levels were close to stipulated limits. With further refinement of combustion equipment, small-scale co-combustion systems have the potential to comply with emission regulations

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

Heavy metals behaviour during mono-combustion and co-combustion of sewage sludge

Energy Technology Data Exchange (ETDEWEB)

Lopes, M. Helena; Abelha, Pedro; Olieveira, J.F. Santos; Gulyurtlu, Ibrahim; Cabrita, Isabel [INETI-DEECA, Lisboa (Portugal)

2005-03-01

This paper presents the study of the combustion of granular dry sewage sludge performed on a pilot fluidized bed system. The results of mono-combustion of sludge and co-combustion with coal were compared with those of coal combustion for ash partitioning, the formation of gaseous pollutants and heavy metals behaviour. It was found that the mineral matter of sludge was essentially retained as bottom ashes. The production of fines ashes was small during the mono-combustion due to the tendency of coal to produce fine ashes which also contained unburned char. The degree of heavy metal volatilization was found to be slightly higher during co-combustion than in mono-combustion; however, most of them were retained in ashes and their emissions were found to be below the regulated levels. Hg was completely volatilized; however, during combustion trials involving coal it was captured by cyclone ashes at temperatures below 300 deg C. During sludge mono-combustion the retention of Hg in cyclone ashes containing low LOI was not enough to decrease emissions below the regulated levels; hence, it is necessary to install dedicated flue gas treatment for Hg removal. The leachability and ecotoxicity of sludge and ashes was compared with the new regulatory limits for landfill disposal in the EU. It was found that the release of organic matter and heavy metals found in the sludge was low from granular bed ashes; hence, except for sulphate release, bed ashes were converted into inert and non-ecotoxic materials. Ashes from test with limestone and cyclone ashes seemed to be more problematic because of pH effects and contamination with steel corrosion products. The recovery and reutilization of sludge bed ashes could, therefore, be possible, as long as the release of sulphate do not interfere with the process.

The effect of sulfur on the inhibition of PCDD/F formation during co-combustion of coal and solid waste

Energy Technology Data Exchange (ETDEWEB)

Palladas, A. [Laboratory of Environmental and Energy Processes, Thermi-Thessaloniki (Greece). Chemical Process Engineering Research Institute; Samaras, P. [TEI of Western Macedonia, Kozani (Greece). Dept. of Environmental Technology; Sakellaropoulos, G. [Aristotle Univ. of Thessaloniki (Greece). Dept. of Chemical Engineering

2004-09-15

Co-combustion of solid wastes with coal is a promising technique used to reduce landfilled wastes, utilizing waste the energy content. However, solid wastes often contain chlorine and other substances, which upon combustion may result in the production of extremely toxic compounds like polychlorinated dibenzo-p-dioxins and dibenzofurans. Various compounds have been proposed for their inhibition ability of PCDD/F formation, including sulphuric and nitrogen containing substances. Sulfur compounds may form some kind of complexes with metal species, reducing thus their ability for catalysing the PCDD/F formation pathways. Sulfur inhibitory capacity has been attributed to reaction with copper catalytic sites, altering their form and presumably their ability to produce Cl{sub 2} through the Deacon process reaction. Another second postulated role of sulfur is to undergo homogeneous reactions, converting the primary chlorinating agent, Cl{sub 2}, into a form (HCl) less likely to undergo aromatic substitution reactions forming PCDD/F precursors. The objectives of this work were the measurement of PCDD/F emissions during co-combustion of different fuel mixtures, and the study of the effect of sulfur addition to the fuel on PCDD/F formation.

Study into the status of co-combustion of sewage sludge, biomass and household refuse in coal-fired power stations. Final report; Untersuchungen zum Stand der Mitverbrennung von Klaerschlamm, Hausmuell und Biomasse in Kohlekraftwerken. Schlussbericht

Energy Technology Data Exchange (ETDEWEB)

Hein, K.R.G.; Spliethoff, H.; Scheurer, W. [Stuttgart Univ. (Germany). Inst. fuer Verfahrenstechnik und Dampfkesselwesen; Seifert, H.; Richers, U. [Forschungszentrum Karlsruhe GmbH Technik und Umwelt (Germany). Inst. fuer technische Chemie - Thermische Abfallbehandlung

2000-03-01

The co-combustion of wastes in power stations is an additional option for the thermal treatment of certain waste materials and thus for complying with the specifications of the German TA-Siedlungsabfall (technical directive on disposal of municipal solid waste). The present investigation compiles the status of knowledge about co-combustion of sewage sludge, biomass and selected waste materials in coal-fired power stations. The results are meant to provide extensive assistance to evaluate the processes and thus to contribute to sort out uncertainties, both on the part of power plant operators and of the authorities. Based on the information acquired, the report shall point out the gaps in knowledge, the further need for research and development and the need for action conerning the authorities. By enquiries at disposal enterprises, power station operators as well as authorities, the literature work was completed and a comprehensive view of the current situation in Germany elaborated. The report points out the legal conditions of co-combustion and supplementary fuel potentials, presents the process engineering of co-combustion, and examines the obstacles encountered during the technical conversion, the environmental questions, and the potential for co-combustion of the above materials in existing power stations. The electrical power sector is subject to strong changes due to the liberalisation of the energy market. The pressure on costs has increased and the periods available for planning are shorter. On the one hand, this arouses an increased interest in co-combustion of waste materials because of possible additional payments for the wastes. On the other hand, however, initiatives in this respect are counteracted by high investments costs necessary for the introduction of co-combustion with the existing high environmental standards. What is more, the competitive situation reduces the exchange of experience between the power station operators. Co-combustion of sewage

An Investigation on Cocombustion Behaviors of Hydrothermally Treated Municipal Solid Waste with Coal Using a Drop-Tube Reactor

Directory of Open Access Journals (Sweden)

Liang Lu

2012-01-01

Full Text Available This work aims at demonstrating the feasibility of replacing Indonesian coal (INC with hydrothermally treated municipal solid waste (MSWH in cocombustion with high ash Indian coal (IC. The combustion efficiencies and emissions (CO, NO of MSWH, INC and their blends with IC for a series of tests performed under a range of temperatures and air conditions were tested in a drop-tube reactor (DTR. The results showed the following. The combustion efficiency of IC was increased by blending both MSWH and INC and CO emission was reduced with increasing temperature. For NO emission, the blending of MSWH led to the increase of NO concentration whereas the effects of INC depended on the temperature. The combustion behaviors of IC-MSWH blend were comparable to those of the IC-INC blend indicating it is possible for MSWH to become a good substitute for INC supporting IC combustion. Moreover, the CO emission fell while the NO emission rose with increasing excess air for IC-MSWH blend at 900°C and the highest combustion efficiency was obtained at the excess air of 1.9. The existence of moisture in the cocombustion system of IC-MSWH blend could slightly improve the combustion efficiency, reduce CO, and increase NO.

Thermogravimetric analysis of co-combustion between microalgae and textile dyeing sludge.

Science.gov (United States)

Peng, Xiaowei; Ma, Xiaoqian; Xu, Zhibin

2015-03-01

The synergistic interaction and kinetics of microalgae, textile dyeing sludge and their blends were investigated under combustion condition by thermogravimetric analysis. The textile dyeing sludge was blended with microalgae in the range of 10-90wt.% to investigate their co-combustion behavior. Results showed that the synergistic interaction between microalgae and textile dyeing sludge improved the char catalytic effect and alkali metals melt-induced effect on the decomposition of textile dyeing sludge residue at high temperature of 530-800°C. As the heating rate increasing, the entire combustion process was delayed but the combustion intensity was enhanced. The lowest average activation energy was obtained when the percentage of microalgae was 60%, which was 227.1kJ/mol by OFW and 227.4kJ/mol by KAS, respectively. Copyright © 2015 Elsevier Ltd. All rights reserved.

Co-combustion of risk husk with coal in a fluidized bed

International Nuclear Information System (INIS)

Ghani, A.K.; Alias, A.B.; Savory, R.M.; Cliffe, K.R.

2006-01-01

Power generation from biomass is an attractive technology which utilizes agricultural residue waste. In order to explain the behavior of biomass-fired fluidized bed incinerator, biomass sources from agricultural residues (rice husk) was co-fired with coal in a 0.15 m diameter and 2.3 m high fluidized bed combustor. The combustion efficiency and CO emissions were studied and compared with those for pure coal combustion. Biomass waste with up to 70% mass fraction can be co-combusted in a fluidized bed combustor designed for coal combustion with a maximum drop of efficiency of 20% depending upon excess air levels. CO levels fluctuated between 200-700 ppm were observed when coal is added. It is evident from this research that efficient co-firing of rice husk with coal can be achieved with minimum modification of existing coal-fired boilers. (Author)

Use and co-combustion of straw in Denmark

Energy Technology Data Exchange (ETDEWEB)

Poulsen, J S [SK Power, Ballerup (Denmark)

1997-12-31

Coal has in more decades been the backbone of the Danish energy production. As a consequence of a political wish to utilize domestic fuel and reduce the massive use of coal and the CO{sub 2} emission, straw has since 1989 been used in Denmark at small-scale combined heat and power plants. All straw-fired combined heat and power plants in Denmark are owned by the power stations. Furthermore some district heating plants owned by the municipalities, consumers or privately owned, also use straw as a fuel, as in the middle of the eighties it was prohibited to use coal as fuel in district heating plants. Different rules of subsidies and duties made natural gas or biomass the most competitive fuel for the district heating plants. For various other reasons there are also some oil-fired district heating plants in operation. Today five straw-fired combined heat and power plants in Denmark are in commercial operation. Three of these plants exclusively use straw as a fuel, one uses both straw, wood chips and natural gas, and one straw and coal. These five combined heat and power plants, having a total annual consumption of straw of approx. 200 000 tonnes, supply district heating to five medium-sized towns. On 14 June 1993 an agreement was made in the Danish Parliament ordering the power stations to reach an annual volume input of 1.2 mill. tonnes of straw and 0.2 mill. tonnes of wood chips in year 2000. Therefore two new plants are under construction and co-combustion with straw is being installed at an existing coal-fired power station. In addition, two large plants are under consideration. With the two plants under construction and with the co-combustion plant, the straw consumption is expected to increase to 430 000 tons of straw per year. These two plants will start operations in 1995 and 1997 respectively. All the operating straw-fired combined heat and power stations show an economic loss. Besides the price of fuel, this is due to the efficiency of the plants, which with

Use and co-combustion of straw in Denmark

Energy Technology Data Exchange (ETDEWEB)

Poulsen, J.S. [SK Power, Ballerup (Denmark)

1996-12-31

Coal has in more decades been the backbone of the Danish energy production. As a consequence of a political wish to utilize domestic fuel and reduce the massive use of coal and the CO{sub 2} emission, straw has since 1989 been used in Denmark at small-scale combined heat and power plants. All straw-fired combined heat and power plants in Denmark are owned by the power stations. Furthermore some district heating plants owned by the municipalities, consumers or privately owned, also use straw as a fuel, as in the middle of the eighties it was prohibited to use coal as fuel in district heating plants. Different rules of subsidies and duties made natural gas or biomass the most competitive fuel for the district heating plants. For various other reasons there are also some oil-fired district heating plants in operation. Today five straw-fired combined heat and power plants in Denmark are in commercial operation. Three of these plants exclusively use straw as a fuel, one uses both straw, wood chips and natural gas, and one straw and coal. These five combined heat and power plants, having a total annual consumption of straw of approx. 200 000 tonnes, supply district heating to five medium-sized towns. On 14 June 1993 an agreement was made in the Danish Parliament ordering the power stations to reach an annual volume input of 1.2 mill. tonnes of straw and 0.2 mill. tonnes of wood chips in year 2000. Therefore two new plants are under construction and co-combustion with straw is being installed at an existing coal-fired power station. In addition, two large plants are under consideration. With the two plants under construction and with the co-combustion plant, the straw consumption is expected to increase to 430 000 tons of straw per year. These two plants will start operations in 1995 and 1997 respectively. All the operating straw-fired combined heat and power stations show an economic loss. Besides the price of fuel, this is due to the efficiency of the plants, which with

Influence of catalysts on co-combustion of sewage sludge and water hyacinth blends as determined by TG-MS analysis.

Science.gov (United States)

Huang, Limao; Xie, Candie; Liu, Jingyong; Zhang, Xiaochun; Chang, KenLin; Kuo, Jiahong; Sun, Jian; Xie, Wuming; Zheng, Li; Sun, Shuiyu; Buyukada, Musa; Evrendilek, Fatih

2018-01-01

Effects of the three metal carbonates (K 2 CO 3 , Na 2 CO 3 , and MgCO 3 ) were quantified on catalytic co-combustion of the sewage sludge and water hyacinth (SW) blend using a thermogravimetric-mass spectrometric (TG-MS) analysis and kinetics modeling. The main dominating steps of the catalysts were the organic volatile matter release and combustion stage. Weighted mean values of activation energy (E m ) were estimated at 181.18KJ·mol -1 , 199.76KJ·mol -1 , 138.76KJ·mol -1 , and 177.88KJ·mol -1 for SW, SW+5% K 2 CO 3 , SW+5% Na 2 CO 3 , and SW+5% MgCO 3 , respectively. The lowest E m occurred with SW+5% Na 2 CO 3 . Overall, catalyst effect on co-combustion appeared to be negligible as indicated by Gibbs free energy (ΔG). The normalized intensities of SW+MgCO 3 were strongest. The addition of Na 2 CO 3 and MgCO 3 to SW increased flue gases emissions (CO 2 , NO 2 , SO 2 , HCN, and NH 3 ) of SW, whereas the addition of K 2 CO 3 to SW reduced flue gases emissions from the entire combustion process. Copyright © 2017 Elsevier Ltd. All rights reserved.

Comparative study of cogasification and co-combustion of communal sewage sludge in brown coal fuelled plants; Vergleich der Mitvergasung und Mitverbrennung kommunaler Klaerschlaemme in braunkohlegefeuerten Anlagen

Energy Technology Data Exchange (ETDEWEB)

Schiffer, H P; Bierbaum, K; Adlhoch, W; Thomas, G [Rheinbraun AG, Koeln (Germany)

1997-12-31

Co-combustion and cogasification of sewage sludge in brown coal fuelled plants are compared, and an economic assessment is made. (ABI) [Deutsch] Die Mitverbrennung und Mitvergasung von Klaerschlamm in braunkohlegefeuerten Anlagen werden verglichen und auf ihre Wirtschaftlichkeit hin untersucht. (ABI)

Comparative study of cogasification and co-combustion of communal sewage sludge in brown coal fuelled plants; Vergleich der Mitvergasung und Mitverbrennung kommunaler Klaerschlaemme in braunkohlegefeuerten Anlagen

Energy Technology Data Exchange (ETDEWEB)

Schiffer, H.P.; Bierbaum, K.; Adlhoch, W.; Thomas, G. [Rheinbraun AG, Koeln (Germany)

1996-12-31

Co-combustion and cogasification of sewage sludge in brown coal fuelled plants are compared, and an economic assessment is made. (ABI) [Deutsch] Die Mitverbrennung und Mitvergasung von Klaerschlamm in braunkohlegefeuerten Anlagen werden verglichen und auf ihre Wirtschaftlichkeit hin untersucht. (ABI)

Ameliorer les performances environnementales des centrales a charbon pulverise via la co-combustion de combustible derive de dechets

Science.gov (United States)

Vekemans, Odile Geraldine

Coal supplies around 28% of the world's energy needs and produces some 40% of the world's electricity. In the United States, close to 650 coal power plants currently produce electricity from coal, the majority of witch are equipped with pulverized coal boilers build in the 80's. Due to coal's intrinsic content in nitrogen and sulfur, its combustion is associated with high levels of NOx and SO2 emissions, that are responsible, among other thing, for acid rains. In order to help reduce SO2 emissions of coal power plant, this thesis focuses on the behaviour of a novel feedstock called ReEF(TM) or ReEngineered Feedstock(TM), developed by the company Accordant Energy LLCRTM, that combines non recyclable waste and alkaline sorbent. Since waste have a high calorific value and do not contain sulfur, and since alkaline sorbents (such as limestone) are able to react with SO2 and capture it in solid state, co-combustion of ReEF(TM) and coal could reduce SO2 emissions inside the furnace chamber itself. This technology easy to implement, as it requires a limited initial investment and limited additional space, could help avoid the construction of costly flue gas treatment unit downstream from the furnace. However, careless combustion of this engineered fuel could have disastrous consequences for the coal power plant owners. This thesis, then, deliver one among the first experimental study of co-combustion of coal and ReEF(TM) in conditions characteristic of pulverized coal boilers. As a first step, in order to get familiarize with the feedstock under study, the thermal degradation of a ReEF(TM) without sorbent and of its components is analyzed by thermogravimetry. With the analysis of more than 70 samples at heating rates ranging from 5°C/min to 400°C/min we are able to conclude that ReEF(TM) thermal degradation can be seen as the independent thermal degradation of its components, as long as heat transfer limitations are taken into account. Thus, no substantial chemical

Modeling and Simulation on NOx and N2O Formation in Co-combustion of Low-rank Coal and Palm Kernel Shell

Directory of Open Access Journals (Sweden)

Mahidin Mahidin

2012-12-01

Full Text Available NOx and N2O emissions from coal combustion are claimed as the major contributors for the acid rain, photochemical smog, green house and ozone depletion problems. Based on the facts, study on those emissions formation is interest topic in the combustion area. In this paper, theoretical study by modeling and simulation on NOx and N2O formation in co-combustion of low-rank coal and palm kernel shell has been done. Combustion model was developed by using the principle of chemical-reaction equilibrium. Simulation on the model in order to evaluate the composition of the flue gas was performed by minimization the Gibbs free energy. The results showed that by introduced of biomass in coal combustion can reduce the NOx concentration in considerably level. Maximum NO level in co-combustion of low-rank coal and palm kernel shell with fuel composition 1:1 is 2,350 ppm, low enough compared to single low-rank coal combustion up to 3,150 ppm. Moreover, N2O is less than 0.25 ppm in all cases. Keywords: low-rank coal, N2O emission, NOx emission, palm kernel shell

Considerations on valorization of biomass origin materials in co-combustion with coal in fluidized beds

Energy Technology Data Exchange (ETDEWEB)

I. Gulyurtlu; P. Abelha; H. Lopes; A. Crujeira; I. Cabrita [DEECA-INETI, Lisbon (Portugal)

2007-07-01

Co-combustion of biomass materials with coal is currently gaining increasing importance, in order to meet the targets on greenhouse gas emissions, defined in the Kyoto protocol. Co-firing of coal with biomass materials could be the short-term solution in reducing CO{sub 2} emissions from power stations. The work undertaken studied co-firing of meat and bone meal (MBM), olive cake and straw pellets with bituminous coals from Colombia (CC) and Poland (PC), which are commonly used in European power stations. The co-combustion studies were carried out on the pilot fluidized bed installation of INETI. Gaseous pollutants and solid concentration in flue gases and ashes from different locations were monitored. Results obtained indicate that the co-feeding of biomass materials did not present any problem and ensured stable combustion conditions and high efficiency. However, for temperatures above 800{sup o}C, bed agglomeration could be observed for all biomass species studied. Most of the combustion of biomass material, contrary to that of coal, was observed to take place in the riser where the temperature was as high as 150-250{sup o}C above that of the bed. SO{sub 2} and NOx levels were found to be lower. The emissions of dioxins could be considerable with fuels with high Cl as is the case with straw. However, mixing of fuels with high S content could lead to a strong reduction in dioxin emissions. Ashes produced from biomass combustion may be considered for further reutilization or landfilling. Other options depend on their characteristics, chemical composition and leaching behaviour. This was evaluated in this study.

Effects of Operating Conditions and Dusty Fuel on the NOx, N2O and CO Emissions in PFB Co-Combustion of Coal and Wood

Czech Academy of Sciences Publication Activity Database

Svoboda, Karel; Pohořelý, Michael; Hartman, Miloslav

2003-01-01

Roč. 17, č. 4 (2003), s. 1091-1099 ISSN 0887-0624 R&D Projects: GA AV ČR IAA4072801 Institutional research plan: CEZ:AV0Z4072921 Keywords : pressurized fluidized bed * co-combustion * wood Subject RIV: JE - Non-nuclear Energetics, Energy Consumption ; Use Impact factor: 1.303, year: 2003

Trace elements in co-combustion of solid recovered fuel and coal

DEFF Research Database (Denmark)

Wu, Hao; Glarborg, Peter; Jappe Frandsen, Flemming

2013-01-01

Trace element partitioning in co-combustion of a bituminous coal and a solid recovered fuel (SRF) was studied in an entrained flow reactor. The experiments were carried out at conditions similar to pulverized coal combustion, with SRF shares of 7.9 wt.% (wet basis), 14.8 wt.% and 25.0 wt.......%. In addition, the effect of additives such as NaCl, PVC, ammonium sulphate, and kaolinite on trace element partitioning was investigated. The trace elements studied were As, Cd, Cr, Pb, Sb and Zn, since these elements were significantly enriched in SRF as compared to coal. During the experiments, bottom ash...... was collected in a chamber, large fly ash particles were collected by a cyclone with a cut-off diameter of ~2.5 μm, and the remaining fly ash particles were gathered in a filter. It was found that when coal was co-fired with SRF, the As, Cd, Pb, Sb and Zn content in filter ash/cyclone ash increased almost...

Current situation regarding the co-combustion of waste materials in power plants; Aktuelle Situation der Mitverbrennung von Abfallstoffen in Kraftwerken

Energy Technology Data Exchange (ETDEWEB)

Schirmer, U.; Krueger, H.; Puch, K.H. [VGB Technische Vereinigung der Grosskraftwerksbetreiber e.V., Essen (Germany)

1998-09-01

In view of the wholly insufficient capacity, relative to current arisings, of waste incineration plants, residue processing plants and plants for the utilisation of other combustible materials we are inevitably faced with the question whether power plant furnaces might not be suited for the thermal treatment and utilisation of wastes and residues. This possibility has been studied by many VGB member companies and seriously investigated for its practicability in several cases. The investigations were premised on the following fundamental positions. The VGB members are prepared to contribute to the solution of the above problems as long as this is possible without detriment to their duties as energy suppliers. They can only assume this responsibility if the requirements of the licensing laws are observed. This concerns the quality and arising quantities of wastes to be taken in, emissions, and the disposal of combustion residues. Power plants typically make more or less complete use of their own process residues, a feature which as far as possible should not be impaired by the co-combustion process. The technical problems posed by the co-combustion of suitable residues and wastes are usually solvable. Co-combustion offers an alternative and a supplement to dedicated waste utilisation plants or plants for the utilisation of suitable residues. Beyond this some companies are interested in profiting from the fees that will be due to them for utilising wastes. From 1990 to 1992 a VGB working group studied the option of co-combustion on the basis of the above premises. The material elaborated by the group now in turn serves as a basis for the following deliberations. [Deutsch] Da die Kapazitaet der Abfallverbrennungsanlagen, der Anlagen zur Reststoffverwertung und der Anlagen zur Nutzung sonstiger brennbaren Stoffe fuer das vorhandene Angebot bei weitem nicht ausreicht, ergibt sich die Frage der Eignung von Kraftwerksfeuerungen zur thermischen Behandlung und Verwertung von

Production of fines during co-combustion of coal with biomass fuels by fragmentation and attrition

Energy Technology Data Exchange (ETDEWEB)

I. Gulyurtlu; D. Boavida; H. Lopes (and others) [DEECA-INETI, Lisbon (Portugal)

2005-07-01

Results are reported from a project funded by the RFCS Programme of the European Union. The aim is to investigate, experimentally and by modeling, the production of fine char and ash particles during co-combustion of coal with wastes and biofuels in circulating fluidized bed. Work was undertaken at installations of different scales. Polish and Colombian coals were base fuels. The additional fuels were two sewage sludges. Bed temperature, feeding system, sand particle size, devolatilisation behaviour and char burn-out were studied to verify their influence on the fine particle production. Modeling was also carried out to understand the mechanisms of fragmentation and attrition. Samples from bed and cyclone were collected to determine particle size distributions. 11 refs.

Co-combustion of biodiesel with oxygenated fuels in direct injection diesel engine

Directory of Open Access Journals (Sweden)

Tutak Wojciech

2017-01-01

Full Text Available The paper presents results of experimental investigation of cocombustion process of biodiesel (B100 blended with oxygenated fuels with 20% in volume. As the alternative fuels ware used hydrated ethanol, methanol, 1-butanol and 2-propanol. It was investigated the influence of used blends on operating parameters of the test engine and exhaust emission (NOx, CO, THC, CO2. It is observed that used blends are characterized by different impact on engine output power and its efficiency. Using biodiesel/alcohol blend it is possible to improve engine efficiency with small drop in indicated mean effective pressure (IMEP. Due to combustion characteristic of biodiesel/alcohol obtained a slightly larger specific NOx emission. It was also observed some differences in combustion phases due to various values of latent heat of evaporation of used alcohols and various oxygen contents. Test results confirmed that the combustion process occurring in the diesel engine powered by blend takes place in a shorter time than in the typical diesel engine.

PCDD/PCDF reduction by the co-combustion process.

Science.gov (United States)

Lee, Vinci K C; Cheung, Wai-Hung; McKay, Gordon

2008-01-01

A novel process, termed the co-combustion process, has been developed and designed to utilise the thermal treatment of municipal solid waste (MSW) in cement clinker production and reduce PCDD/PCDF emissions. To test the conceptual design; detailed engineering design of the process and equipment was performed and a pilot plant was constructed to treat up to 40 tonnes MSW per day. The novel process features included several units external to the main traditional cement rotary kiln: an external calcinations unit in which the hot gas calcined the limestone thus making significant energy savings for this chemical reaction; the lime generated was used in a second chamber to act as a giant acid gas scrubber to remove SOx and particularly HCl (a source of chloride); an external rotary kiln and secondary combustion unit capable of producing a hot gas at 1200 degrees C; a gas cooler to simulate a boiler turbogenerator set for electricity generation; the incorporation of some of the bottom ash, calcined lime and dust collector solids into the cement clinker. A PCDD/PCDF inventory has been completed for the entire process and measured PCDD/PCDF emissions were 0.001 ng I-TEQ/Nm(3) on average which is 1% of the best practical means [Hong Kong Environmental Protection Department, 2001. A guidance note on the best practicable means for incinerators (municipal waste incineration), BPM12/1] MSW incineration emission limit values.

Effect of phosphorous transformation on the reduction of PM{sub 10} formation during Co-combustion of coal and sewage sludge

Energy Technology Data Exchange (ETDEWEB)

Zhuo, J.K.; Dong, M.; Li, G.D.; Li, S.Q.; Song, Q.; Yao, Q. [Tsinghua Univ., Beijing (China). Key Lab. of Thermal Science and Power Engineering; Duan, L. [Tsinghua Univ., Beijing (China). Dept. of Environmental Science and Engineering

2013-07-01

Co-combustion of Municipal Sewage Sludge with coal will become increasingly widely used, regarded as an important incineration method with the high thermal efficiency, low emissions, low investment and operating costs. However, the presence of phosphorus in fine particle has gained increased attention due to its environmental adverse affection and deactivation of SCR DeNOx catalysts. Therefore, the behavior of phosphorus in fine particles during co-combustion of coal and sewage sludge was investigated in a 25 kW quasi one-dimensional down-fired pulverized coal combustor, where PM{sub 10} was collected from the furnace centerline in the outlet of flue gas cooler by using a two-stage nitrogen-aspirated, water-cooling isokinetic sampling probe followed a 13-stage electric low pressure impactor. Then the formation mechanism of PM{sub 10} was investigated by observing the different fractions of sewage sludge in the coal. Similar to the coal combustion, the particle-size-distributions (PSD) of PM{sub 10} mass concentration by co-combustion of sewage sludge with coal exhibit two distinct modes separated by a fraction of 0.157-0.263 {mu}m, ultrafine mode and intermediate mode. With the sewage sludge blended sludge up to 15% (thermal ratio), the mass concentration of the total fly ash and PM{sub 10+} (Dp > 10 {mu}m) vastly increased from 1,088 and 547 mg/Nm{sup 3} (during coal combustion) to 5,059 and 4,403 mg/Nm{sup 3}. However, the mass concentration of fine particulates, such as PM{sub 1}, PM{sub 2.5} and PM{sub 10} was maintained at the emission level of coal combustion. When the fraction of sewage sludge less than 15%, the mass concentration of fine particle is higher than the emission during coal combustion, while the growth rate is only by the 3.6, 7.9 and 4.8% of the total concentration of fly ash (5% thermal). The change of the PSD of mass concentration during co- combustion of sewage sludge and coal, mainly was caused by the interaction between Si, Al and Ca, Fe

Environmental, physical and structural characterisation of geopolymer matrixes synthesised from coal (co-)combustion fly ashes

International Nuclear Information System (INIS)

Alvarez-Ayuso, E.; Querol, X.; Plana, F.; Alastuey, A.; Moreno, N.; Izquierdo, M.; Font, O.; Moreno, T.; Diez, S.; Vazquez, E.; Barra, M.

2008-01-01

The synthesis of geopolymer matrixes from coal (co-)combustion fly ashes as the sole source of silica and alumina has been studied in order to assess both their capacity to immobilise the potentially toxic elements contained in these coal (co-)combustion by-products and their suitability to be used as cement replacements. The geopolymerisation process has been performed using (5, 8 and 12 M) NaOH solutions as activation media and different curing time (6-48 h) and temperature (40-80 o C) conditions. Synthesised geopolymers have been characterised with regard to their leaching behaviour, following the DIN 38414-S4 [DIN 38414-S4, Determination of leachability by water (S4), group S: sludge and sediments. German standard methods for the examination of water, waste water and sludge. Institut fuer Normung, Berlin, 1984] and NEN 7375 [NEN 7375, Leaching characteristics of moulded or monolithic building and waste materials. Determination of leaching of inorganic components with the diffusion test. Netherlands Normalisation Institute, Delft, 2004] procedures, and to their structural stability by means of compressive strength measurements. In addition, geopolymer mineralogy, morphology and structure have been studied by X-ray diffraction (XRD), scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR), respectively. It was found that synthesised geopolymer matrixes were only effective in the chemical immobilisation of a number of elements of environmental concern contained in fly ashes, reducing (especially for Ba), or maintaining their leachable contents after the geopolymerisation process, but not for those elements present as oxyanions. Physical entrapment does not seem either to contribute in an important way, in general, to the immobilisation of oxyanions. The structural stability of synthesised geopolymers was mainly dependent on the glass content of fly ashes, attaining at the optimal activation conditions (12 M NaOH, 48 h, 80 o C

Co-combustion of coal and non-recyclable paper & plastic waste in a fluidised bed reactor

Energy Technology Data Exchange (ETDEWEB)

Boavida, D.; Abelha, P.; Gulyurtlu, I.; Cabrita, I. [DEECA-INETI, Lisbon (Portugal)

2002-07-01

Co-combustion of waste with coal was carried out using a fluidised bed combustor with the aim of achieving a fuel mixture with little variations in its heating value and simultaneously reducing the accumulation of non-toxic waste material by upgrading them for energy purposes. Results obtained indicate that the feeding of waste materials could present serious problems which could render conditions for a stable combustion difficult to achieve. The waste was fed mixed with coal and there was some difference observed in results regarding the combustion efficiency and emissions. Part of the combustion of waste material, contrary to that of coal, was observed to take place in the freeboard where the temperature was as much as 150{degree}C above that of the bed. 6 refs., 8 figs., 8 tabs.

Faecal-wood biomass co-combustion and ash composition analysis.

Science.gov (United States)

Somorin, Tosin Onabanjo; Kolios, Athanasios J; Parker, Alison; McAdam, Ewan; Williams, Leon; Tyrrel, Sean

2017-09-01

Fuel blending is a widely used approach in biomass combustion, particularly for feedstocks with low calorific value and high moisture content. In on-site sanitation technologies, fuel blending is proposed as a pre-treatment requirement to reduce moisture levels and improve the physiochemical properties of raw faeces prior to drying. This study investigates the co-combustion performance of wood dust: raw human faeces blends at varying air-to-fuel ratios in a bench-scale combustor test rig. It concludes with ash composition analyses and discusses their potential application and related problems. The study shows that a 50:50 wood dust (WD): raw human faeces (FC) can reduce moisture levels in raw human faeces by ∼40% prior to drying. The minimum acceptable blend for treating moist faeces without prior drying at a combustion air flow rate of 14-18 L/min is 30:70 WD: FC. For self-sustained ignition and flame propagation, the minimum combustion temperature required for conversion of the fuel to ash is ∼400 °C. The most abundant elements in faecal ash are potassium and calcium, while elements such as nickel, aluminium and iron are in trace quantities. This suggests the potential use of faecal ash as a soil conditioner, but increases the tendency for fly ash formation and sintering problems.

Co-combustion of agricultural wastes in a circulating fluidized bed

Energy Technology Data Exchange (ETDEWEB)

Huseyin Topal; Aysel T. Atimtay [Gazi University, Ankara (Turkey). Dept. of Mechanical Engineering

2005-07-01

In this study a circulating fluidized bed combustion (CFBC) of 125 mm inside diameter and 1800 mm height was used to investigate the co-combustion characteristics of peach and apricot stones produced as a waste from the fruit juice industry, and sunflower stems produced as a waste from the edible oil industry with a lignite coal. Lignite coal is a coal most widely used in Turkey. On-line concentrations of O{sub 2}, CO, CO{sub 2}, SO{sub 2}, NOx and total hydrocarbons (C{sub m}H{sub n}) were measured in the flue gas during combustion experiments. By changing the operating parameters the variation of emissions of various pollutants were studied. During combustion tests, it was observed that the volatile matter from agro-wastes quickly volatilizes and mostly burn in the riser. The temperature profiles along the bed and the rise also confirmed this phenomenon. It was found that as the volatile matter content of agro-waste increases, the combustion efficiency increases and the combustion takes place more in the upper region of the riser. These results suggest that agro-wastes are potential fuels that can be utilized for clean energy production by using CFBC in countries where agricultural activities are heavy. 3 refs., 4 figs., 5 tabs.

Co-combustion of pulverized coal and solid recovered fuel in an entrained flow reactor- General combustion and ash behavior

DEFF Research Database (Denmark)

Wu, Hao; Glarborg, Peter; Frandsen, Flemming

2011-01-01

.9 wt.%, 14.8 wt.% and 25 wt.%, respectively. The effect of additives was evaluated by maintaining the share of secondary fuel (mixture of SRF and additive) at 14.8 wt.%. The experimental results showed that the fuel burnout, NO and SO2 emission in co-combustion of coal and SRF were decreased...... with increasing share of SRF. The majority of the additives inhibited the burnout, except for NaCl which seemed to have a promoting effect. The impact of additives on NO emission was mostly insignificant, except for ammonium sulphate which greatly reduced the NO emission. For SO2 emission, it was found that all...

Results concerning a clean co-combustion technology of waste biomass with fossil fuel, in a pilot fluidised bed combustion facility

Energy Technology Data Exchange (ETDEWEB)

Ionel, Ioana; Trif-Tordai, Gavril; Ungureanu, Corneliu; Popescu, Francisc; Lontis, Nicolae [Politehnica Univ. Timisoara (Romania). Faculty for Mechanical Engineering

2008-07-01

The research focuses on a facility, the experimental results, interpretation and future plans concerning a new developed technology of using waste renewable energy by applying the cocombustion of waste biomass with coal, in a fluidised bed system. The experimental facility is working entirely in accordance to the allowed limits for the exhaust flue gas concentration, with special concern for typical pollutants. The experiments conclude that the technology is cleaner, has as main advantage the possibility to reduce both the SO{sub 2} and CO{sub 2} exhaust in comparison to standard fossil fuel combustion, under comparable circumstances. The combustion is occurring in a stable fluidised bed. (orig.)

Environmental evaluation of sewage sludge co-combustion in a pilot FBC

Energy Technology Data Exchange (ETDEWEB)

M. Helena Lopes; P. Abelha; I. Cabrita; J.F.Santos Oliveira; I. Gulyurtlu [INETI/DEECA, Lisbon (Portugal)

2003-07-01

This paper presents a comparison of combustion of coal alone with that of a mixture of coal with sewage sludge with respect to flue gas emissions, the behaviour of heavy metals and potential environmental consequences of disposal of ashes produced. Co-combustion with sludge did not result in greater NOx, SO{sub 2}, HCl and CO emissions and the use of air staging and the addition of limestone proved to be effective to reduce NOx and SO{sub 2}. The mixing of sludge gave rise to an increase in amounts of heavy metals released, especially for Cd, Pb and Hg. However, as they were associated with particles greater than 1 {micro}m, the application of efficient flue gas treatment devices could decrease their emissions to the atmosphere. Metals were essentially retained in ashes captured in the bed and in the cyclones and most of the Hg was adsorbed in fly ashes that contained unburned carbon. The leachability of metals and organic matter present in the sludge decreased with combustion. The evaluation of the acid neutralization capacity (ANC) showed that ashes became more resistant to acidification than the parent sludge. Globally, this study concludes that the implication of the combustion of sludge is that it can reduce the negative impact on the environment compared with the traditional direct use of sludge in soils. 22 refs., 4 figs., 5 tabs.

A quick scan of economic value of offshore wind versus biomass co-combustion; Quick scan economische waarde van wind op zee versus biomassabijstook

Energy Technology Data Exchange (ETDEWEB)

Rooijers, F.J.; Bennink, D.; Blom, M.J.

2013-05-15

Co-combustion of biomass in conventional power stations is currently cheaper than offshore wind power. By the year 2025, though, both forms of renewable energy are expected to be similarly priced. Because offshore wind yields more added value for the Dutch economy and employment than biomass cocombustion, it would seem more logical to earmark more of the funds under the SDE (Dutch renewable energy subsidy scheme) for the former. At the request of the Netherlands Society for Nature and Environment (Natuur en Milieu) CE Delft compared the two generating options to assess how the Netherlands can boost use of renewable energy in the economically wisest manner in the years ahead. This issue is also to be discussed in upcoming consultations under the umbrella of the Netherlands Social and Economic Council (SER), where a new national energy agreement is to be hammered out [Dutch] Biomassabijstook is op dit moment goedkoper dan wind op zee. De verwachting is echter dat tegen 2025 de prijs van beide vormen van hernieuwbare energie vergelijkbaar kunnen zijn. Doordat de toegevoegde waarde voor de Nederlandse economie en werkgelegenheid van wind op zee groter is dan van biomassabijstook, lijkt het logischer dat uit de SDE-gelden meer wind op zee dan biomassa bijstook wordt betaald. Voor Natuur en Milieu heeft CE Delft een vergelijking gemaakt tussen deze twee technieken om de vraag te beantwoorden op welke economisch verstandige manier Nederland de komende jaren het gebruik van hernieuwbare energie kan realiseren. Die vraag is ook aan de orde in het SER-overleg dat de komende maand moet leiden tot een Energieakkoord.

Co-combustion for fossil fuel replacement and better environment

Energy Technology Data Exchange (ETDEWEB)

Lopes, M. Helena; Gulyurtlu, Ibrahim; Abelha, Pedro; Teixeira, P.; Crujeira, Teresa; Boavida, Dulce; Marques, F.; Cabrita, Isabel [INETI/DER, Lisboa (Portugal)

2006-07-01

The growing demand for energy and the requirements regarding CO{sub 2} emissions to comply with the Kyoto targets, together with crisis associated with the fuel supply, can be, to some degree, met by the use of renewable fuel sources, such as biomass. Although the use of biomass, originating from forests, could be beneficial, particularly in preventing fires, there are obstacles to achieve a sustainable supply of biomass in most European countries. In addition, there are also technical barriers as biomass combustion conditions may differ from those of coal, which could mean significant retrofitting of existing installations. The significance of this problem was recognized in the EU and a Project is being financed by the 6th Framework Programme, INETI from Portugal being the coordinator. Five EU countries plus Turkey participate in the project which aims at evaluating both the sustainable chain supply in the several countries, taking profit of the experience of northern European countries and the technical issues related with the co-combustion process, pollutant emission control and operational problems, such as fouling and slagging inside the boilers. At INETI, experimental work is being carried out, involving the characterization of several types of biomass and non-toxic residues. These materials are being burned on a pilot fluidized bed combustor, in order to evaluate combustion performance and improve conditions and synergies of fuel blends to control pollutant emissions and slagging tendency. Ashes produced are also being characterized, for composition and leachability, in order to evaluate possibilities of reutilization and compliance with landfilling regulations. In this paper a description of the project is presented, along with some of the results already obtained.

Co-combustion for fossil fuel replacement and better environment

Energy Technology Data Exchange (ETDEWEB)

M. Helena Lopes; I. Gulyurtlu; P. Abelha; P. Teixeira; T. Crujeira; D. Boavida; F. Marques; I. Cabrita [INETI, Lisbon (Portugal)

2006-07-01

The growing demand for energy and the requirement regarding CO{sub 2} emissions, to comply with the Kyoto targets, together with crisis associated with the fuel supply, can be, to some degree, met by the use of renewable fuel sources, such as biomass. Although the use of biomass, originating from forests, could be beneficial, there are obstacles to achieve a sustainable supply of biomass in most European countries. In addition, there are also technical barriers as biomass combustion conditions may differ from those of coal, which could mean significant retrofitting of existing installations. The significance of this problem was recognized in the EU and a Project is being financed by the 6th Framework Programme, INETI from Portugal being the coordinator. Five EU countries plus Turkey participate in the project which aims at evaluating both the sustainable chain supply in the several countries, taking profit of the experience of northern European countries and the technical issues related with the co-combustion process, pollutant emission control and operational problems, such as fouling and slagging inside the boilers. At INETI, experimental work is being carried out, involving the characterization of several types of biomass and non-toxic residues. These materials are being burned on a pilot fluidized bed combustor, in order to evaluate combustion performance and improve conditions and synergies of fuel blends to control pollutant emissions and slagging tendency. Ashes produced are also being characterized, for composition and leachability, in order to evaluate possibilities of reutilization and compliance with landfilling regulations. In this paper a description of the project is presented, along with some of the results already obtained. 19 refs., 5 figs., 7 tabs.

Co-combustion of coal and non-recyclable paper and plastic waste in a fluidised bed reactor

Energy Technology Data Exchange (ETDEWEB)

D. Boavida; P. Abelha; I. Gulyurtlu; I. Cabrita [DEECA-INETI, Lisbon (Portugal)

2003-10-01

Co-combustion of waste with coal was carried out using a fluidised bed combustor with the aim of achieving a fuel mixture with little variations in its heating value and simultaneously reducing the accumulation of non-toxic waste material by upgrading them for energy purposes. Results obtained indicate that the feeding of waste materials plays an important role to achieve conditions for a stable combustion. The form in which the fuel is fed to the combustor makes a significant contribution to achieve desirable combustion performance and differences were observed in results regarding the combustion efficiency and emissions when waste was fed densified or in a fluffy state when it was burned mixed with coal. Part of the combustion of waste material, contrary to that of coal, was observed to take place in the freeboard where the temperature was as much as 150{sup o}C above that of the bed. 15 refs., 8 figs., 8 tabs.

Co-combustion performance of coal with rice husks and bamboo

Energy Technology Data Exchange (ETDEWEB)

Kwong, P.C.W.; Chao, C.Y.H.; Wang, J.H.; Cheung, C.W.; Kendall, G. [Hong Kong University of Science & Technology, Kowloon (China). Dept. of Mechanical Engineering

2007-11-15

Biomass has been regarded as an important form of renewable energy due to the reduction of greenhouse gas emission such as carbon dioxide. An experimental study of co-combustion of coal and biomass was performed in a laboratory-scale combustion facility. Rice husks and bamboo were the selected biomass fuels in this study due to their abundance in the Asia-Pacific region. Experimental parameters including the biomass blending ratio in the fuel mixture, relative moisture content and biomass grinding size were investigated. Both energy release data and pollutant emission information were obtained. Due to the decrease in the heating value from adding biomass in the fuel mixture, the combustion temperature and energy output from the co-firing process were reduced compared with coal combustion. On the other hand, gaseous pollutant emissions including carbon monoxide (CO), carbon dioxide (CO{sub 2}), nitrogen oxides (NOx) and sulfur dioxide (SO{sub 2}) were reduced and minimum energy-based emission factors were found in the range of 10-30% biomass blending ratio. With an increase in the moisture content in the biomass, decreases in combustion temperature, SO{sub 2}, NOx and CO{sub 2} emissions were observed, while an increase in CO emissions was found. It has also been observed that chemical kinetics may play an important role compared to mass diffusion in the co-firing process and the change in biomass grinding size does not have much effect on the fuel burning rate and pollutant emissions tinder the current experimental conditions.

Formation of fine particles in co-combustion of coal and solid recovered fuel in a pulverized coal-fired power station

DEFF Research Database (Denmark)

Wu, Hao; Pedersen, Anne Juul; Glarborg, Peter

2011-01-01

showed an ultrafine mode centered at approximately 0.1 μm. Compared with coal combustion, co-combustion of coal and SRF increased the formation of submicron particles, especially ultrafine particles below 0.2 μm. The morphology of the particles indicated that supermicron particles were primarily formed...... by the melting of minerals. The ultrafine particles were generated through nucleation and coagulation of vaporized inorganic species, while for the particles in between supermicron and ultrafine particles, condensation of vaporized species or aggregation of nucleates on the existing spherical submicron particles...... appear to be an important formation mechanism. The elemental composition of the particles from coal combustion showed that S and Ca were significantly enriched in ultrafine particles and P was also enriched considerably. However, compared with supermicron particles, the contents of Al, Si and K were...

Comparative study of coal and biomass co-combustion with coal burning separately through emissions analysis

International Nuclear Information System (INIS)

Siddique, M.; Asadullah, A.; Khan, G.; Soomro, S.A.

2016-01-01

Appropriate eco-friendly methos to mitigate the problem of emissions from combustion of fossil fuel are highly demanded. The current study was focused on the effect of using coal and coal biomass co-combustion on the gaseous emissions. Different biomass were used along with coal. The coal used was lignite coal and the biomass' were tree waste, cow dung and banana tree leaves Various ratios of coal and biomass were used to investigate the combustion behavior of coal cow dung and 100% banana tree leaves emits less emission of CO, CO/sub 2/, NOx and SO/sub 2/ as compared to 100% coal, Maximum amount of CO emission were 1510.5 ppm for bannana tree waste and minimum amount obtained for lakhra coal and cow dung manure (70:30) of 684.667 leaves (90:10) and minimum amount of SO/sub 2/ present in samples is in lakhra coal-banana tree waste (80:20). The maximum amount of NO obtained for banana tree waste were 68 ppm whereas amount from cow dung manure (30.83 ppm). The study concludes that utilization of biomass with coal could make remedial action against environment pollution. (author)

Prediction of Agglomeration, Fouling, and Corrosion Tendency of Fuels in CFB Co-Combustion

Science.gov (United States)

Barišć, Vesna; Zabetta, Edgardo Coda; Sarkki, Juha

Prediction of agglomeration, fouling, and corrosion tendency of fuels is essential to the design of any CFB boiler. During the years, tools have been successfully developed at Foster Wheeler to help with such predictions for the most commercial fuels. However, changes in fuel market and the ever-growing demand for co-combustion capabilities pose a continuous need for development. This paper presents results from recently upgraded models used at Foster Wheeler to predict agglomeration, fouling, and corrosion tendency of a variety of fuels and mixtures. The models, subject of this paper, are semi-empirical computer tools that combine the theoretical basics of agglomeration/fouling/corrosion phenomena with empirical correlations. Correlations are derived from Foster Wheeler's experience in fluidized beds, including nearly 10,000 fuel samples and over 1,000 tests in about 150 CFB units. In these models, fuels are evaluated based on their classification, their chemical and physical properties by standard analyses (proximate, ultimate, fuel ash composition, etc.;.) alongside with Foster Wheeler own characterization methods. Mixtures are then evaluated taking into account the component fuels. This paper presents the predictive capabilities of the agglomeration/fouling/corrosion probability models for selected fuels and mixtures fired in full-scale. The selected fuels include coals and different types of biomass. The models are capable to predict the behavior of most fuels and mixtures, but also offer possibilities for further improvements.

Characteristics of ammonia emission during thermal drying of lime sludge for co-combustion in cement kilns.

Science.gov (United States)

Liu, Wei; Xu, Jingcheng; Liu, Jia; Cao, Haihua; Huang, Xiang-Feng; Li, Guangming

2015-01-01

Thermal drying was used to reduce sludge moisture content before co-combustion in cement kilns. The characteristics of ammonia (NH3) emission during thermal drying of lime sludge (LS) were investigated in a laboratory-scale tubular dry furnace under different temperature and time conditions. As the temperature increased, the NH3 concentration increased in the temperature range 100-130°C, decreased in the temperature range 130-220°C and increased rapidly at >220°C. Emission of NH3 also increased as the lime dosage increased and stabilized at lime dosages>5%. In the first 60 min of drying experiments, 55% of the NH3 was released. NH3 accounted for about 67-72% of the change in total nitrogen caused by the release of nitrogen-containing volatile compounds (VCs) from the sludge. X-ray photoelectron spectroscopy and Fourier-transform infrared spectroscopy revealed that the main forms of nitrogen in sludge were amides and amines. The addition of lime (CaO) could cause conversion of N-H, N-O or C-N containing compounds to NH3 during the drying process.

3-DIMENSIONAL SIMULATION AND FEASIBILITY STUDY OF BIOMASS/COAL CO-COMBUSTION BURNER

Directory of Open Access Journals (Sweden)

Nataliya DUNAYEVSKA

2017-06-01

Full Text Available Combustion of solid biomass mixed with coal in existing boilers not only reduces harmful emissions, but also allows diversifying the available fuel base. Such technology allows to implement the efficient use of food industry solid wastes, which otherwise would be dumped in piles, and thus produce harmful environmental impact. The geometrical models of research reactor and a burner thermal preprocessing of pulverized coal were developed and calculational meshes were generated. The geometrical model of the VGP-100Vpresents only fluid domain whereas the effect of cooled walls was substituted by the equivalent biudary conditions deruved on the basis of direct experimentation. The model of the VGP-100V allowed accounting for the specifics of radiative heat transfer by comparison of experimental thermo-couple measurements to the simulated by the model one. A model has been developed allowing the determination of actual temperatures of combustion gases flow based upon the reading of unsheathed thermo-couples by taking into account the reradiation of the thermo-couple beads to the channel walls. Based on the ANSYS 3-D process model in the burner of the Trypilska Thermal Power Plant (TPP for the combustion of low-reactive coal with the thermochemical preparation of the design of an actual burner has been developed. On the basis of the experimental studies of the actual burner and the above-mentioned CFD calculations, the burner draft of the 65 MW for TPP-210A boiler aimed at the implementation of biomass-coal co-combustion was designed.

Nitrogen evolution during the co-combustion of hydrothermally treated municipal solid waste and coal in a bubbling fluidized bed.

Science.gov (United States)

Lu, Liang; Jin, Yuqi; Liu, Hongmei; Ma, Xiaojun; Yoshikawa, Kunio

2014-01-01

Nitrogen evolution was studied during the co-combustion of hydrothermally treated municipal solid wastes (HT MSW) and coal in a bubbling fluidized bed (BFB). HT MSW blending ratios as 10%, 20% and 30% (wt.%) were selected and tested at 700, 800, 900 °C. Emissions of NO and N2O from blends were measured and compared with the results of mono-combustion trials. Moreover, concentrations of precursors like NH3 and HCN were also quantified. The results are summarized as follows: NO emissions were predominant in all the cases, which rose with increasing temperature. The blending of HT MSW contributed to the NO reduction. N2O emissions decreased with temperature rising and the blending of HT MSW also presented positive effects. At 30% HT MSW addition, both NO and N2O emissions showed the lowest values (391.85 ppm and 55.33 ppm, respectively at 900 °C). For the precursors, more HCN was detected than NH3 and both played important roles on the gas side nitrogen evolution. Copyright © 2013. Published by Elsevier Ltd.

Co-combustion characteristics and blending optimization of tobacco stem and high-sulfur bituminous coal based on thermogravimetric and mass spectrometry analyses.

Science.gov (United States)

Zhang, Kaihua; Zhang, Kai; Cao, Yan; Pan, Wei-ping

2013-03-01

Despite much research on co-combustion of tobacco stem and high-sulfur coal, their blending optimization has not been effectively found. This study investigated the combustion profiles of tobacco stem, high-sulfur bituminous coal and their blends by thermogravimetric analysis. Ignition and burnout performances, heat release performances, and gaseous pollutant emissions were also studied by thermogravimetric and mass spectrometry analyses. The results indicated that combustion of tobacco stem was more complicated than that of high-sulfur bituminous coal, mainly shown as fixed carbon in it was divided into two portions with one early burning and the other delay burning. Ignition and burnout performances, heat release performances, and gaseous pollutant emissions of the blends present variable trends with the increase of tobacco stem content. Taking into account the above three factors, a blending ratio of 0–20% tobacco stem content is conservatively proposed as optimum amount for blending. Copyright © 2012 Elsevier Ltd. All rights reserved.

Investigation of co-combustion characteristics of sewage sludge and coffee grounds mixtures using thermogravimetric analysis coupled to artificial neural networks modeling.

Science.gov (United States)

Chen, Jiacong; Liu, Jingyong; He, Yao; Huang, Limao; Sun, Shuiyu; Sun, Jian; Chang, KenLin; Kuo, Jiahong; Huang, Shaosong; Ning, Xunan

2017-02-01

Artificial neural network (ANN) modeling was applied to thermal data obtained by non-isothermal thermogravimetric analysis (TGA) from room temperature to 1000°C at three different heating rates in air to predict the TG curves of sewage sludge (SS) and coffee grounds (CG) mixtures. A good agreement between experimental and predicted data verified the accuracy of the ANN approach. The results of co-combustion showed that there were interactions between SS and CG, and the impacts were mostly positive. With the addition of CG, the mass loss rate and the reactivity of SS were increased while charring was reduced. Measured activation energies (E a ) determined by the Kissinger-Akahira-Sunose (KAS) and Ozawa-Flynn-Wall (OFW) methods deviated by <5%. The average value of E a (166.8kJ/mol by KAS and 168.8kJ/mol by OFW, respectively) was the lowest when the fraction of CG in the mixture was 40%. Copyright © 2016 Elsevier Ltd. All rights reserved.

Preparation and co-combustion of whole plants in a coal dust furnace; Aufbereitung und Mitverbrennung von Ganzpflanzen mit Steinkohle in einer Staubfeuerung

Energy Technology Data Exchange (ETDEWEB)

Siegle, V; Spliethoff, H; Hein, K R.G. [Stuttgart Univ. (Germany). Inst. fuer Verfahrenstechnik und Dampfkesselwesen (IVD)

1997-12-31

Co-combustion is a favourable and simple way of utilizing biomass. Owing to the high energy density of grains, whole plants must be ground very thoroughly for use in a coal dust furnace. This can be done with low energy consumption in a hammer mill. In addition, multifuel swirl burners permit selective supply of fuel and low-NO{sub x} combustion. The fuel with the highest nitrogen content should be blown into the inner recirculation zone. (orig) [Deutsch] Die Mitverbrennung von Biomasse ist eine guenstige und schnell zu realisierende Moeglichkeit, Biomasse in grossem Umfang zu nutzen. Um Ganzpflanzen in einer Staubfeuerung mitverbrennen zu koennen, muessen diese aufgrund der hohen Energiedichte der Koerner sehr fein aufgemahlen werden. Dies ist mit einer Hammermuehle mit geringem Energieeinsatz moeglich. Durch eine geeignete Sichtung muss diese jedoch noch weiter optimiert werden. Mit Multi-Fuel-Drallbrennern ist eine stickoxidarme Verbrennung moeglich. Der Brennstoff, der den groesseren Stickstoffeintrag in die Flamme bewirkt, soltle in die innere Rezirkulationszone eingeblasen werden. (orig)

Preparation and co-combustion of whole plants in a coal dust furnace; Aufbereitung und Mitverbrennung von Ganzpflanzen mit Steinkohle in einer Staubfeuerung

Energy Technology Data Exchange (ETDEWEB)

Siegle, V.; Spliethoff, H.; Hein, K.R.G. [Stuttgart Univ. (Germany). Inst. fuer Verfahrenstechnik und Dampfkesselwesen (IVD)

1996-12-31

Co-combustion is a favourable and simple way of utilizing biomass. Owing to the high energy density of grains, whole plants must be ground very thoroughly for use in a coal dust furnace. This can be done with low energy consumption in a hammer mill. In addition, multifuel swirl burners permit selective supply of fuel and low-NO{sub x} combustion. The fuel with the highest nitrogen content should be blown into the inner recirculation zone. (orig) [Deutsch] Die Mitverbrennung von Biomasse ist eine guenstige und schnell zu realisierende Moeglichkeit, Biomasse in grossem Umfang zu nutzen. Um Ganzpflanzen in einer Staubfeuerung mitverbrennen zu koennen, muessen diese aufgrund der hohen Energiedichte der Koerner sehr fein aufgemahlen werden. Dies ist mit einer Hammermuehle mit geringem Energieeinsatz moeglich. Durch eine geeignete Sichtung muss diese jedoch noch weiter optimiert werden. Mit Multi-Fuel-Drallbrennern ist eine stickoxidarme Verbrennung moeglich. Der Brennstoff, der den groesseren Stickstoffeintrag in die Flamme bewirkt, soltle in die innere Rezirkulationszone eingeblasen werden. (orig)

Investigation on the co-combustion of oil shale and municipal solid waste by using thermogravimetric analysis

International Nuclear Information System (INIS)

Fan, Yunlong; Yu, Zhaosheng; Fang, Shiwen; Lin, Yan; Lin, Yousheng; Liao, Yanfen; Ma, Xiaoqian

2016-01-01

Highlights: • Co-combustion of oil shale with municipal solid waste created significant changes. • Blending with municipal solid wastes could improve the combustion performance. • 10–30% of oil shale in the blends could be determined as the optimum ratio range. • Activation energy were calculated by the conversion rate and different proportion. - Abstract: The aim of this study is trying to reveal the thermal characteristics and kinetics of oil shale, municipal solid waste and their blends in the combustion process which are needed for efficient utilization. The combustion experiment is carried out in a thermogravimetric simultaneous thermal analyzer, where the temperature ranged from 110 °C to 900 °C at three different heating rates as 10 °C/min, 20 °C/min and 30 °C/min. Their kinetics were studied by Ozawa–Flynn–Wall and Friedmen methods. According to the data analysis, combustion characteristic index increased progressively with the increase of the proportion of municipal solid waste. And it’s suggested that there was certain interaction in the combustion process of oil shale and municipal solid waste. The average activation energy of the blends reached the minimum value, 177.7927 kJ/mol by Ozawa–Flynn–Wall method and 167.4234 kJ/mol by Friedmen method, when the proportion of MSW was 70%.

Operation related on-line measurements of low temperature fire side corrosion during co-combustion of biomass and oil; Driftrelaterad direktmaetning av laagtemperaturkorrosion i en braensleeldad kraftvaermeanlaeggning

Energy Technology Data Exchange (ETDEWEB)

Eriksson, Thomas [Studsvik Nuclear AB, Nykoeping (Sweden)

2000-05-01

A number of combustion plants have experienced corrosion attack on air preheaters and economisers when fired with biomass fuels. In certain plants the problems are great and reconstruction has been performed so that exposed components can be exchanged during operation. The electrochemical techniques offer on-line measurements of the changes in corrosion rate in the low temperature region in a waste incinerator. The purpose with this study was to evaluate the technique in a biomass fired boiler where the corrosion rate is considerable lower compared to a waste incinerator. Experiments were performed at the Haesselby plant, boiler 3, which was fired with pure biomass as well as a mixture of biomass and oil during the test period. It was found that the electrochemical technique is a useful tool for on-line measurements of the changes in corrosion rate in biomass fired utilities. Since the corrosion rate in the low temperature region is dependent on the boiler construction, electrochemical measurements give valuable information on the corrosion rate during optimisation of the fuel mixture, SNCR and temperature or the low temperature components. This is of special importance when introducing new fuels or fuel mixtures. Soot blowing is of prime importance for the total corrosion. During a few minutes an individual soot blower can initiate such a high corrosion rate that it represents the total corrosion. The material temperature is another important parameter. Above a certain temperature the corrosion rate is negligible. During co-combustion this temperature was found to be in the region 65-85 deg C. The influence of the SNCR with ammonia, with respect to corrosion, is dependent on the fuel mixture used. In utilities where acidic combustion products are formed, ammonia has a neutralising effect e.g. in Hoegdalen. At the Haesselby plant this neutralising effect was not found. During cocombustion with oil the ammonia forms ammoniahydrosulphate which increases the corrosion

Comparative Study of Coal and Biomass Co-Combustion With Coal Burning Separately Through Emissions Analysis

Directory of Open Access Journals (Sweden)

Mohammad Siddique

2016-06-01

Full Text Available Appropriate eco-friendly methods to mitigate the problem of emissions from combustion of fossil fuel are highly demanded. The current study was focused on the effect of using coal & coal-biomass co-combustion on the gaseous emissions. Different biomass' were used along with coal. The coal used was lignite coal and the biomass' were tree waste, cow dung and banana tree leaves. Various ratios of coal and biomass were used to investigate the combustion behavior of coal-biomass blends and their emissions. The study revealed that the ratio of 80:20 of coal (lignite-cow dung and 100% banana tree leaves emits less emissions of CO, CO2, NOx and SO2 as compared to 100% coal. Maximum amount of CO emissions were 1510.5 ppm for banana tree waste and minimum amount obtained for lakhra coal and cow dung manure (70:30 of 684.667 ppm. Maximum percentage of SO2 (345.33 ppm was released from blend of lakhra coal and tree leaves (90:10 and minimum amount of SO2 present in samples is in lakhra coal-banana tree waste (80:20. The maximum amount of NO obtained for banana tree waste were 68 ppm whereas maximum amount of NOx was liberated from lakhra coal-tree leaves (60:40 and minimum amount from cow dung manure (30.83 ppm. The study concludes that utilization of biomass with coal could make remedial action against environment pollution.

Thermogravimetric analysis of the co-combustion of paper mill sludge and municipal solid waste

International Nuclear Information System (INIS)

Hu, Shanchao; Ma, Xiaoqian; Lin, Yousheng; Yu, Zhaosheng; Fang, Shiwen

2015-01-01

Highlights: • Thermogravimetric analysis of paper mill sludge and municipal solid waste were studied. • The combustion of paper mill sludge could be improved by blending municipal solid waste. • There existed significant interaction during co-combustion of the blends. • The OFW and Starink methods were used to obtain the activation energy. • The average activation energy was the lowest by blending 20% municipal solid waste. - Abstract: The thermal characteristics and kinetics of paper mill sludge (PMS), municipal solid waste (MSW) and their blends in the combustion process were investigated in this study. The mass percentages of PMS in the blends were 10%, 30%, 50%, 70% and 90%, respectively. The experiments were carried out at different heating rates (10 °C/min, 20 °C/min and 30 °C/min) and the temperature ranged from room temperature to 1000 °C in a thermogravimetric simultaneous thermal analyzer. The results suggested that the ignition temperature and burnout temperature of MSW were lower than that of PMS, and the mass loss rate of MSW was larger especially at low temperatures. There were only two mass loss peaks in the differential thermogravimetry (DTG) curve, while three mass loss peaks were observed when the blending ratios of PMS were 30%, 50%, 70%. The value of the comprehensive combustion characteristic index of the blends indicated a good combustibility when the percentage of PMS (PPMS) in the blends was less than 30%. There existed certain interaction between the combustion process of PMS and MSW, especially at high temperature stage. Activation energy (E) value obtained by the Ozawa–Flynn–Wall (OFW) method and the Starink method were very consistent. When the mass percentage of PMS in the blends was 80%, the E average value attained the minimum

Energy recovery and emissions of PBDD/Fs and PBDEs from cocombustion of woodchip and wastewater sludge in an industrial boiler.

Science.gov (United States)

Chang, Shun-Shiang Chang; Lee, Wen-Jhy Lee; Wang, Lin-Chi Wang; Chang-Chien, Guo-Ping Chang-Chien; Wu, Chang-Yu

2013-01-01

The emissions of polybrominated dibenzo-pdioxins,dibenzofurans (PBDD/Fs), and polybrominated diphenyl ethers (PBDEs) from trial combustion of 10 wt % dried industrial wastewater-treatment sludge (IWTS) and 90 wt % woodchip in an industrial boiler were investigated and compared to that from woodchip combustion. The PBDD/F toxic equivalent (TEQ) andPBDE emissions increased from 0.121 pg TEQ Nm−3 and 2260 pgNm−3, respectively, of the woodchip combustion to 0.211 pg TEQNm−3 and 4200 pg Nm−3, respectively, of the trial combustion.PBDD/F and PBDE congener profiles of inputs and outputs of the same type of combustion were similar; they also show similarity between woodchip and trial combustions, revealing that the destruction pathway was little affected by the introduction of the IWTS. The fates of PBDD/Fs and PBDEs show that the indigenous pollutants in the feed were effectively depleted (>93.5%). The dominant releasing route of PBDD/F and PBDE shifted from the stack flue gas of woodchip combustion to the ashes of trial combustion. This study demonstrates that co-combustion not only handles the fast growing sludge stream but also yields a saving of 26.3% in the fuel cost and treatment fees of sludge and ashes.

Thermodynamics and kinetics parameters of co-combustion between sewage sludge and water hyacinth in CO2/O2 atmosphere as biomass to solid biofuel.

Science.gov (United States)

Huang, Limao; Liu, Jingyong; He, Yao; Sun, Shuiyu; Chen, Jiacong; Sun, Jian; Chang, KenLin; Kuo, Jiahong; Ning, Xun'an

2016-10-01

Thermodynamics and kinetics of sewage sludge (SS) and water hyacinth (WH) co-combustion as a blend fuel (SW) for bioenergy production were studied through thermogravimetric analysis. In CO2/O2 atmosphere, the combustion performance of SS added with 10-40wt.% WH was improved 1-1.97 times as revealed by the comprehensive combustion characteristic index (CCI). The conversion of SW in different atmospheres was identified and their thermodynamic parameters (ΔH,ΔS,ΔG) were obtained. As the oxygen concentration increased from 20% to 70%, the ignition temperature of SW decreased from 243.1°C to 240.3°C, and the maximum weight loss rate and CCI increased from 5.70%·min(-1) to 7.26%·min(-1) and from 4.913%(2)·K(-3)·min(-2) to 6.327%(2)·K(-3)·min(-2), respectively, which corresponded to the variation in ΔS and ΔG. The lowest activation energy (Ea) of SW was obtained in CO2/O2=7/3 atmosphere. Copyright © 2016 Elsevier Ltd. All rights reserved.

Advanced air staging techniques to improve fuel flexibility, reliability and emissions in fluidized bed co-combustion

Energy Technology Data Exchange (ETDEWEB)

Aamand, Lars-Erik; Leckner, Bo [Chalmers Technical Univ., Goeteborg (Sweden); Luecke, Karsten; Werther, Joachim [Technical Univ. of Hamburg-Harburg (Germany)

2001-12-01

A joint research project between the Technical University of Hamburg-Harburg and Chalmers Technical University. For operation under co-combustion the following results should be considered: The high ash content of the sewage sludge results in significantly increased ash flows. Although high alkali metal concentrations are found in the sewage sludge ash, no critical concentrations were reached and tendencies to fouling were not observed. The trace metal input rises with increased sludge fraction. However, emissions of metal compounds were well below legal limits. The trace metals tend to accumulate on the fly ash. In general, very low fuel nitrogen conversions to NO and N{sub 2}O of 2 - 4 % are achievable. With coal as a base fuel alternative air staging with secondary air supply after solids separation attains even lower NO emissions than normal staging without strongly affecting CO and SO{sub 2} emissions. Alternative staging also reduces N{sub 2}O emissions. An optimum for the excess air ratio in the riser of 1.05 was found for a total excess air ratio of 1.2. The higher the volatile content of the fuel is, the less effective the NO reduction due to air staging becomes. The measurements suggest that the optimum gas residence time regarding the emissions in CFB combustors is around 6 to 7 s. These times are achieved in commercial scale plants due to their large cyclones that perhaps partly can replace a large afterburner chamber. The circulating fluidized bed boiler can be operated in a very flexible way with various fuel mixtures up to an energy fraction of sludge of 25% without exceeding legal emission limits.

Impact of co-combustion of petroleum coke and coal on fly ash quality: Case study of a Western Kentucky power plant

International Nuclear Information System (INIS)

Hower, James C.; Thomas, Gerald A.; Mardon, Sarah M.; Trimble, Alan S.

2005-01-01

Petroleum coke has been used as a supplement or replacement for coal in pulverized-fuel combustion. At a 444-MW western Kentucky power station, the combustion of nearly 60% petroleum coke with moderate- to high-sulfur Illinois Basin coal produces fly ash with nearly 50% uncombusted petroleum coke and large amounts of V and Ni when compared to fly ash from strictly pulverized coal burns. Partitioning of the V and Ni, known from other studies to be concentrated in petroleum coke, was noted. However, the distribution of V and Ni does not directly correspond to the amount of uncombusted petroleum coke in the fly ash. Vanadium and Ni are preferentially associated with the finer, higher surface area fly ash fractions captured at lower flue gas temperatures. The presence of uncombusted petroleum coke in the fly ash doubles the amount of ash to be disposed, makes the fly ash unmarketable because of the high C content, and would lead to higher than typical (compared to other fly ashes in the region) concentrations of V and Ni in the fly ash even if the petroleum coke C could be beneficiated from the fly ash. Further studies of co-combustion ashes are necessary in order to understand their behavior in disposal

Full Scale Deposition Trials at 150 MWe PF-boiler Co-firing COal and Straw: Summary of Results

DEFF Research Database (Denmark)

Andersen, Karin Hedebo; Frandsen, Flemming; Hansen, Peter Farkas Binderup

1999-01-01

A conventional PF-fired boiler at the Danish energy company I/S Midtkraft has been converted to coal-straw co-combustion and a two-year demonstration programme was initiated in January 1996 addressing several aspects of coal-straw co-combustion. Deposition trials were performed as part...... during co-combustion with straw. In addition, where Fe dominated upstream deposits are found in the hottest positions during pure coal combustion, Ca, and to some degree Si, are playing the major role during co-combustion. The addition of straw to the fuel is also seen to lead to a change in the texture...... of the upstream deposits, from an ordered dendritic structure of the larger particles with small particles in between during pure coal combustion, to a more random deposition of the larger particles among the small during co-combustion. No deposition of chlorine species was observed in the SEM-EDX analysis...

Shea meal and cotton stalk as potential fuels for co-combustion with coal.

Science.gov (United States)

Munir, S; Nimmo, W; Gibbs, B M

2010-10-01

The efficient management of waste biomass is an important environmental problem in agricultural countries. Often land-fill is the main disposal route with ramifications including CH(4) release having 21 times greater global warming potential per molecule than CO(2). Biomasses are considered to be CO(2)-neutral fuels when combusted. Moreover, they are renewable and covered by the renewable obligation scheme and eligible for certificates in the UK. The overall objective of the investigation is to assess the performance of selected biomass and coal co-firing under two different modes of operation, air-staging and fuel-staging with the benefit of reduced-NO(x) and SO(2) emissions in power plant. The biomasses chosen for the study, shea meal (SM) and cotton stalk (CS) have very different cellulose/lignin compositions and different reported thermal behaviour. A series of experiments have been carried out in a 20 kW, down fired combustor using coal, shea meal-coal and cotton stalk-coal blends under un-staged, air-staged and fuel-staged co-combustion configurations. For air-staging, an optimum value of primary zone stoichiometry SR(1)=0.9 was found. Keeping it fixed, the shea meal and cotton stalk content in the coal-biomass blends was set to 5%, 10% and 15% on thermal basis. NO reductions of 51% and 60% were achieved using SM and CS, respectively, with an optimum thermal biomass blending ratio (BBR) of 10%. The results obtained were compared with un-staged and air-staged results for coal without the addition of biomass. Similarly for fuel-staging, keeping the length of the reburn and burnout zone fixed, SM and CS were evaluated as reductive fuel using different reburn fuel fractions (R(ff)) of 5%, 10%, 15% and 20%. NO reductions of 83% and 84% were obtained with an optimum R(ff) of 15% with an optimum reburn zone stoichiometry of SR(2)=0.8 for both SM and CS, respectively. SO(2) reduction and char burnout efficiency were also evaluated. It was found that addition of

The behaviour of ashes and heavy metals during the co-combustion of sewage sludges in a fluidised bed

Energy Technology Data Exchange (ETDEWEB)

Lopes, M.H.; Abelha, P.; Lapa, N.; Oliveira, J.S.; Cabrita, I.; Gulyurtlu, I. [INETI, Lisbon (Portugal)

2003-07-01

Co-combustion tests of dry sewage sludges with coal were performed in a pilot bubbling FBC with the aim of characterizating the ashes and determining the behaviour of heavy metals in the process. The tests showed compliance with the regulatory levels as far as heavy metal emissions were concerned. The bottom ashes, which accounted for about 70% of the total ash production, were obtained in a granular form, with diameters ranging from 0.5 to 4 mm. The heavy metals were distributed in ashes obtained from different locations of the installation and their concentrations were found to vary depending on the location of capture. The increase in heavy metals content in bottom ashes was not found to lead to higher leachability and ecotoxicity compared to sewage sludges. Mercury suffered vaporisation inside the reactor, thus leaving bottom ashes free of contamination by it. However, there was observed a strong retention of mercury in cyclone ashes due to the presence of unburned carbon which probably acted as an adsorbent. The effluent mercury was also found to be mostly associated with the particulate fraction, being less than 20% emitted in gaseous forms. The results suggested that the combustion of the sewage sludge could successfully be carried out and the amount of unburned carbon leaving the combustor but captured in cyclone was large enough to ensure substantial retention of mercury at low temperatures, hence could contribute to an improvement of the mercury release which still remains an issue of great concern to resolve during combustion of waste materials.

The behaviour of ashes and heavy metals during the co-combustion of sewage sludges in a fluidised bed.

Science.gov (United States)

Helena Lopes, M; Abelha, P; Lapa, N; Oliveira, J S; Cabrita, I; Gulyurtlu, I

2003-01-01

Co-combustion tests of dry sewage sludges with coal were performed in a pilot bubbling FBC aiming at the characterization of ashes and determining the behaviour of heavy metals in the process. The tests showed compliance with the regulatory levels as far as heavy metal emissions were concerned. The bottom ashes, which accounted for about 70% of the total ash production, were obtained in a granular form, with diameters ranging from 0.5 to 4 mm. The heavy metals were distributed in ashes obtained from different locations of the installation and their concentrations were found to vary depending on the location of capture. The increase in heavy metals content in bottom ashes was not found to lead to higher leachability and ecotoxicity compared to sewage sludges, suggesting that there could be opportunities for their further use. Mercury suffered vaporisation inside the reactor, thus leaving bottom ashes free of contamination by it. However, there was observed a strong retention of mercury in cyclone ashes due to the presence of unburned carbon which probably acted as an adsorbent. The effluent mercury was also found to be mostly associated with the particulate fraction, being less than 20% emitted in gaseous forms. The results suggested that the combustion of the sewage sludge could successfully be carried out and the amount of unburned carbon leaving the combustor but captured in cyclone was large enough to ensure substantial retention of mercury at low temperatures, hence could contribute to an improvement of the mercury release which still remains an issue of great concern to resolve during combustion of waste materials.

The behaviour of ashes and heavy metals during the co-combustion of sewage sludges in a fluidised bed

International Nuclear Information System (INIS)

Helena Lopes, M.; Abelha, P.; Lapa, N.; Oliveira, J.S.; Cabrita, I.; Gulyurtlu, I.

2003-01-01

Co-combustion tests of dry sewage sludges with coal were performed in a pilot bubbling FBC aiming at the characterization of ashes and determining the behaviour of heavy metals in the process. The tests showed compliance with the regulatory levels as far as heavy metal emissions were concerned. The bottom ashes, which accounted for about 70% of the total ash production, were obtained in a granular form, with diameters ranging from 0.5 to 4 mm. The heavy metals were distributed in ashes obtained from different locations of the installation and their concentrations were found to vary depending on the location of capture. The increase in heavy metals content in bottom ashes was not found to lead to higher leachability and ecotoxicity compared to sewage sludges, suggesting that there could be opportunities for their further use. Mercury suffered vaporisation inside the reactor, thus leaving bottom ashes free of contamination by it. However, there was observed a strong retention of mercury in cyclone ashes due to the presence of unburned carbon which probably acted as an adsorbent. The effluent mercury was also found to be mostly associated with the particulate fraction, being less than 20% emitted in gaseous forms. The results suggested that the combustion of the sewage sludge could successfully be carried out and the amount of unburned carbon leaving the combustor but captured in cyclone was large enough to ensure substantial retention of mercury at low temperatures, hence could contribute to an improvement of the mercury release which still remains an issue of great concern to resolve during combustion of waste materials

Reduced ash related operational problems (slagging, bed agglomeration, corrosion and fouling) by co-combustion biomass with peat; Minskade askrelaterade driftsproblem (belaeggning, slaggning, hoegtemperatur-korrosion, baeddagglomerering) genom inblandning av torv i biobraenslen

Energy Technology Data Exchange (ETDEWEB)

Oehman, Marcus; Boman, Christoffer; Erhardsson, Thomas; Gilbe, Ram; Pommer, Linda; Bostroem, Dan; Nordin, Anders; Samuelsson, Robert; Burvall, Jan

2006-12-15

Combustion studies were performed in both a fluidized bed (5 kW) and in an under-feed pellets burner (20 kW) to elucidate the responsible mechanisms for the positive effects on ash related operational problems (i.e. slagging, fouling, corrosion and bed agglomeration) during co-combustion of several problematic biomass with peat. Three typical carex-containing Swedish peat samples with differences in e.g. silicon-, calcium- and sulfur contents were co-fired with logging residues, willow and straw in proportions corresponding to 15-40 weight %d.s. Mixing of corresponding 20 wt-% of peat significantly reduced the bed agglomeration tendencies for all fuels. The fuel specific agglomeration temperature were increased by 150-170 deg C when adding peat to the straw fuel and approximately 70-100 deg C when adding peat to the logging residue- and the willow fuel. The increased level of calcium in the inner bed particle layer caused by the added reactive calcium from the peat and/or removing alkali in the gas phase to a less reactive particular form via sorption and/or reaction with reactive peat ash (containing calcium, silica etc.) during which larger particles (>1{mu}m) are formed where collected potassium is present in a less reactive form, is considered to be the dominated reason for the increased agglomeration temperatures during combustion of logging residues and willow. During straw combustion, the ash forming matter were found as individual ash sticky particles in the bed. The iron, sulphur and calcium content of these individual ash particles were significantly increased when adding peat to the fuel mix thereby decreasing the stickiness of these particles i.e. reducing the agglomeration tendencies. Adding peat to the relatively silicon-poor fuels (willow and logging residues) resulted in higher slagging tendencies, especially when the relative silicon rich peat fuel (Brunnskoelen) was used. However, when co-combusting peat with the relatively silicon and potassium

Case study of an MBT plant producing SRF for cement kiln co-combustion, coupled with a bioreactor landfill for process residues.

Science.gov (United States)

Grosso, Mario; Dellavedova, Stefano; Rigamonti, Lucia; Scotti, Sergio

2016-01-01

The paper describes the performances of the energy recovery pathway from the residual waste based on the production of a Solid Recovered Fuel (SRF) to be exploited via co-combustion in a cement kiln. The SRF is produced in a single stream Mechanical-Biological Treatment plant, where bio-drying of the waste is followed by mechanical refining in order to fulfil the quality requirements by the cement kilns. Peculiar of this MBT is the fact that sorting residues are disposed in a nearby landfill, managed according to a bioreactor approach, where landfill gas is collected for electric energy recovery. A detailed mass and energy balance of the system is presented based on one year operational data, followed by its Life Cycle Assessment. Results show that the system is energetically and environmentally effective, with most of the impacts being more than compensated by the savings of materials and energy. Major role in determining such outcome is the displacement of petcoke in the cement kiln, both in terms of its fossil CO2 emissions and of its life cycle impacts, including the trans-oceanic transport. To check the robustness of the results, two sensitivity analyses are performed on the landfill gas collection efficiency and on the avoided electric energy mix. Copyright © 2015 Elsevier Ltd. All rights reserved.

Co-combustion of wood biomass in coal power plants, a contribution to energy turnaround and climate protection?; Die Mitverbrennung holzartiger Biomasse in Kohlekraftwerken. Ein Beitrag zur Energiewende und zum Klimaschutz?

Energy Technology Data Exchange (ETDEWEB)

Vogel, Claudia; Herr, Michael; Edel, Matthias; Seidl, Hannes

2011-08-15

Co-combustion of wood biomass in coal power plants is feasible at short notice and can is a low-cost option for climate protection. While other EU states have already provided funding mechanism, Germany has not followed this lead so far. Domestic wood resources are limited and unevenly distributed among the German regions, so that wood materials will have to be imported. During the past few years, the basic requirements for imports of wood were provided with the initiation of a global pellets market. Sustainability criteria for wood consumption were defined, and international certification systems were developed. The sustainability criteria should be extended to cover also wood-like materials and other biomass for power generation. The German EEG (Renewables Act) is a first step in this direction. Further, investments must be made in logistics capacities. The available logistics of coal power plants can be used with some minor modifications. In all, successful and sustainable international biomass markets may soon be available.

Effect of secondary fuels and combustor temperature on mercury speciation in pulverized fuel co-combustion: part 1

Energy Technology Data Exchange (ETDEWEB)

Shishir P. Sable; Wiebren de Jong; Ruud Meij; Hartmut Spliethoff [Delft University Technology, Delft (Netherlands). Section Energy Technology, Department of Process and Energy

2007-08-15

The present work mainly involves bench scale studies to investigate partitioning of mercury in pulverized fuel co-combustion at 1000 and 1300{sup o}C. High volatile bituminous coal is used as a reference case and chicken manure, olive residue, and B quality (demolition) wood are used as secondary fuels with 10 and 20% thermal shares. The combustion experiments are carried out in an entrained flow reactor with a fuel input of 7-8 kWth. Elemental and total gaseous mercury concentrations in the flue gas of the reactor are measured on-line, and ash is analyzed for particulate mercury along with other elemental and surface properties. Animal waste like chicken manure behaves very differently from plant waste. The higher chlorine contents of chicken manure cause higher ionic mercury concentrations whereas even with high unburnt carbon, particulate mercury reduces with increase in the chicken manure share. This might be a problem due to coarse fuel particles, low surface area, and iron contents. B-wood and olive residue cofiring reduces the emission of total gaseous mercury and increases particulate mercury capture due to unburnt carbon formed, fine particles, and iron contents of the ash. Calcium in chicken manure does not show any effect on particulate or gaseous mercury. It is probably due to a higher calcium sulfation rate in the presence of high sulfur and chlorine contents. However, in plant waste cofiring, calcium may have reacted with chlorine to reduce ionic mercury to its elemental form. According to thermodynamic predictions, almost 50% of the total ash is melted to form slag at 1300{sup o}C in cofiring because of high calcium, iron, and potassium and hence mercury and other remaining metals are concentrated in small amounts of ash and show an increase at higher temperatures. No slag formation was predicted at 1000{sup o}C. 24 refs., 8 figs., 4 tabs.

The behavior of ashes and heavy metals during the co-combustion of sewage sludges in a fluidised bed

Energy Technology Data Exchange (ETDEWEB)

Lopes, Helena M.; Abelha, P.; Cabrita, I. [INETI-DEECA, Lisboa (Portugal); Lapa, N.; Oliveira, J.S. [UNL-Ubia, Monte de Caparica (Portugal)

2003-07-01

Co-combustion tests of dry sewage sludges with coal were performed in a pilot bubbling FRC aiming at the characterization of ashes and determining the behaviour of heavy metals in the process. The tests showed compliance with the regulatory levels as far as heavy metal emissions were concerned. The bottom ashes, which accounted for about 70% of the total ash production, were obtained in a granular form, with diameters ranging from 0.5 to 4 mm. The heavy metals were distributed in ashes obtained from different locations of the installation and their concentrations were found to vary depending on the location of capture. The increase in heavy metals content in bottom ashes was not found to lead to higher leachability and ecotoxicity compared to sewage sludges, suggesting that there could be opportunities for their reactor further use. Mercury suffered vaporisation inside the reactor, thus leaving bottom ashes free of contamination by it. However, there was observed a strong retention of mercury in cyclone ashes due to the presence of unburned carbon which probably acted as an adsorbent. The effluent mercury was also found to be mostly associated with the particulate fraction, being less than 20% emitted in gaseous forms. The results suggested that the combustion of the sewage sludge could successfully be carried out, and the amount of unburned carbon leaving the combustor but captured in the cyclone was large enough to ensure substantial retention of mercury at low temperatures, and, hence, could contribute to an improvement of the mercury release, which still remains an issue of great concern to resolve during combustion of waste materials.

Optimization of use of waste in the future energy system

DEFF Research Database (Denmark)

Münster, Marie; Meibom, Peter

2011-01-01

of mixed waste, anaerobic digestion of organic waste, and gasification of part of the potential RDF (refuse derived fuel) for CHP (combined heat and power) production, while the remaining part is co-combusted with coal. Co-combustion mainly takes place in new coal-fired power plants, allowing investments...... production in Denmark in a 2025 scenario with 48% renewable energy. Investments in a range of waste conversion technologies are facilitated, including waste incineration, co-combustion with coal, anaerobic digestion, and gasification. The most economically feasible solutions are found to be incineration...

A global equilibrium analysis of co-firing coal and solid recovered fuel

DEFF Research Database (Denmark)

Wu, Hao; Glarborg, Peter; Jappe Frandsen, Flemming

Global equilibrium calculations have been performed to study the behavior of ash forming species in cocombustion of a bituminous coal and a solid recovered fuel (SRF). It revealed that co-combustion of coal and 25% SRF (weight basis) could significantly reduce the formation of NaCl (g) and KCl (g...

Investigations of co-combustion of plastics in a coal dust furnace; Untersuchungen zur Mitverbrennung von Kunststoffen in einer Kohlestaubfeuerung

Energy Technology Data Exchange (ETDEWEB)

Gerhardt, T; Spliethoff, H; Hein, K R.G. [Stuttgart Univ. (Germany). Inst. fuer Verfahrenstechnik und Dampfkesselwesen (IVD); Christill, M; Kicherer, A; Seifert, H [BASF AG, Verfahrenstechnik-ZET/EH-L544, Ludwigshafen am Rhein (Germany)

1997-12-31

In a cooperation project of the Institute of Process Engineering and Power Plant TEchnology (IVD) at the University of Stuttgart and the BASF AG, investigations of co-combustion of plastic material in a coal dust furnace were carried out. The central question of the research work was the ignition and burnout of the particles in dependence of the residence time in the hot part of the furnace. Particle sizes were varied with the aim to define the largest possible particle size in order to minimize the cost of fuel preparation by grinding. On the other hand, tests were made with pure materials and synthetic mixtures of these in order to characterize the influence of different types of plastic. The investigations showed that plastics are suited as fuels for coal dust furnaces, and that the cost of fuel preparation can be reduced to an acceptable level. With polyethylene, which is difficult to ignite, an upper particle size limit of 1.25 to 1.5 mm was reached in the IVD test stand. In industrial applications with a different burner arrangement, even better results may be expected. (orig/AKB) [Deutsch] In einer Zusammenarbeit zwischen dem Institut fuer Verfahrenstechnik und Dampfkesselwesen (IVD) der Universitaet Stuttgart und der BASF AG wurden Versuche zur Coverbrennung von Kunststoffen in einer Kohlenstaubfeuerung durchgefuehrt. Im Mittelpunkt der Untersuchungen standen Zuendung und Abbrand der Kunststoffpartikel in Abhaengigkeit von der Verweilzeit im heissen Bereich der Brennkanner. Variiert wurden hierzu zum einen die Partikelgroessen mit dem Ziel, den Aufbereitungsaufwand durch Zerkleinerung zu minimieren. Zur Charakterisierung der Einfluesse verschiedener Kunststoffarten wurden die Versuche mit unterschiedlichen Reinkunststoffen und synthetischen Mischungen durchgefuehrt. Die Versuche zeigen, dass sich Kunststoffe mit vertretbarem Mahlaufwand in der Staubfeuerung einsetzen lassen. Am Beispiel des Polyethylen, eines der thermogravimetrischen Analyse nach relativ

Investigations of co-combustion of plastics in a coal dust furnace; Untersuchungen zur Mitverbrennung von Kunststoffen in einer Kohlestaubfeuerung

Energy Technology Data Exchange (ETDEWEB)

Gerhardt, T.; Spliethoff, H.; Hein, K.R.G. [Stuttgart Univ. (Germany). Inst. fuer Verfahrenstechnik und Dampfkesselwesen (IVD); Christill, M.; Kicherer, A.; Seifert, H. [BASF AG, Verfahrenstechnik-ZET/EH-L544, Ludwigshafen am Rhein (Germany)

1996-12-31

In a cooperation project of the Institute of Process Engineering and Power Plant TEchnology (IVD) at the University of Stuttgart and the BASF AG, investigations of co-combustion of plastic material in a coal dust furnace were carried out. The central question of the research work was the ignition and burnout of the particles in dependence of the residence time in the hot part of the furnace. Particle sizes were varied with the aim to define the largest possible particle size in order to minimize the cost of fuel preparation by grinding. On the other hand, tests were made with pure materials and synthetic mixtures of these in order to characterize the influence of different types of plastic. The investigations showed that plastics are suited as fuels for coal dust furnaces, and that the cost of fuel preparation can be reduced to an acceptable level. With polyethylene, which is difficult to ignite, an upper particle size limit of 1.25 to 1.5 mm was reached in the IVD test stand. In industrial applications with a different burner arrangement, even better results may be expected. (orig/AKB) [Deutsch] In einer Zusammenarbeit zwischen dem Institut fuer Verfahrenstechnik und Dampfkesselwesen (IVD) der Universitaet Stuttgart und der BASF AG wurden Versuche zur Coverbrennung von Kunststoffen in einer Kohlenstaubfeuerung durchgefuehrt. Im Mittelpunkt der Untersuchungen standen Zuendung und Abbrand der Kunststoffpartikel in Abhaengigkeit von der Verweilzeit im heissen Bereich der Brennkanner. Variiert wurden hierzu zum einen die Partikelgroessen mit dem Ziel, den Aufbereitungsaufwand durch Zerkleinerung zu minimieren. Zur Charakterisierung der Einfluesse verschiedener Kunststoffarten wurden die Versuche mit unterschiedlichen Reinkunststoffen und synthetischen Mischungen durchgefuehrt. Die Versuche zeigen, dass sich Kunststoffe mit vertretbarem Mahlaufwand in der Staubfeuerung einsetzen lassen. Am Beispiel des Polyethylen, eines der thermogravimetrischen Analyse nach relativ

Environmental assessment of waste incineration and alternatives; Miljoevurdering af affaldsforbraending og alternativer

Energy Technology Data Exchange (ETDEWEB)

Moeller, J.; Fruergaard, T.; Riber, C.; Astrup, T.; Hoejlund Christensen, T.

2008-06-15

Life cycle environmental assessment of waste combustion and alternatives were made using the LCA model EASEWASTE. Possible environmental effects for nine effect categories and the resource consumption of fossil fuels through treating 1 ton combustible waste were defined for several waste systems, including waste-only incineration, co-combustion in a fossil-fueled cogeneration plant, and combined biogas and compost production from household waste. The main conclusions of the analyses are: 1) with an optimum location, i.e. in the vicinity to a coal-fueled cogeneration plant, waste-only incineration, co-combustion , and combined biogas and compost production are all equal environmentally viable alternatives . 2) Regarding potential toxic impacts in the area of a coal-fueled cogeneration plant, waste-only incineration and combined biogas and compost production will result in slightly less net emissions compared to co-combustion because of better flue gas cleaning of heavy metals in incinerators than in power plants. 3) Siting the incinerator in a decentralized natural gas cogeneration area, co-combustion in a cogeneration plant is a better solution. 4) Combined biogas and compost production and waste-only combustion are environmentally equal treatments in all power plant areas. (ln)

Co-sintering of treated APC-residues with bottom ash

DEFF Research Database (Denmark)

Jensen, Dorthe Lærke; Bergfeldt, Britta; Vehlow, Jürgen

2001-01-01

the influence of co-sintering of Ferrox products with bottom ashes on the quality of the residues and the effects on the combustion process. Only few elements showed higher concentrations in the bottom ashes of these co-combustion tests compared to reference tests. No significant effect on the leaching......Air pollution control residues stabilised by means of the Ferrox process can be sager disposed of due to lower contents of soluble salts and lesssoluble heavy metals stabilised in iron oxides. Co-combustion tests in the Karlsruhe test incinerator TAMARA were carried out in order to investigate...... behaviour of the bottom ashes could be found. During the co-combustion process an increase in SO2 concentrations in the raw gas and slightly lower temperatures in the fuel bed could be observed....

Biomass power for rural development. Quarterly report, September 23, 1996--December 31, 1996

Energy Technology Data Exchange (ETDEWEB)

Cooper, J.T.

1997-02-01

Goals for the biomass power for rural development include: expanded feedstock research and demonstration activities to provide soil-specific production costs and yield data, as well as better methods for harvest and transport; four thousand acres of feedstock available for fueling a commercial venture; comparison of the feasibility of gasification and cocombustion; designs for on-site switchgrass handling and feeding system; a detailed assessment of utilizing switchgrass for gasification and cocombustion to generate electricity using turbines and fuel cells.

Measures for simultaneous minimization of alkali related operating problems, Phase 3. Frame work; Aatgaerder foer samtidig minimering av alkalirelaterade driftproblem, Etapp 3. Ramprogram

Energy Technology Data Exchange (ETDEWEB)

Herstad Svaerd, Solvie; Steenari, Britt-Marie; Aamand, Lars-Erik (and others)

2011-01-15

The positive effects of co-combustion with digested sewage sludge on bed agglomeration, deposit composition and initial corrosion have been studied at Chalmers 12 MW CFB-boiler. The trials comprised co-combustion of 4 different sludges and the results were compared with addition of phosphate and sulphate in the cyclone inlet. The base fuel was a mixture of 20 % sorted waste pellets and 80 % bark pellets. Corrosion studies were also carried out at the Haendeloe 75 MW CFB boiler firing 50% household waste and 50% industrial waste. Test rings of chromium rich material (304L and Sanicro 28) were exposed for 24 and about 400 hours with and without cocombustion with digested sewage sludge. Two lab studies have also been carried out; the corrosivity of different phosphates and the effect on bed agglomeration when co-firing 'small amounts' of digested sewage sludge

Problematic issues of air protection during thermal processes related to the energetic uses of sewage sludge and other waste. Case study: Co-combustion in peaking power plant.

Science.gov (United States)

Hroncová, Emília; Ladomerský, Juraj; Musil, Juraj

2018-03-01

Currently, it is necessary to deal with issues related to the emissions as there is a constantly increasing interest in combusting sludge from sewage treatment plants in the boilers for wood. An analysis of the energetic importance of the combustion of sewage sludge has already been carried out, but the effects of various treatments of the sludge are not always clear, e.g. composting and subsequent combustion to the air pollution. Investments in other thermal processes of energetic utilisation of sewage sludge and organic waste are not always successfully implemented. The objective of this paper is to point out some problematic cases for acceptance of thermal processes related to energetic use of waste in terms of the air protection. The other aim is to mention the experience with solutions of such issues in Slovakia. There are mentioned first results of the operational validation experiments during the energy generation in circulating fluidized bed boiler in peaking power plant (Power 110MW) with the addition of the so-called alternative fuel based on wood and sewage sludge to the main fuel - black coal (anthracite). And there has already been achieved the highest share of 12.4%w. (dry matter) of sewage sludge in form of compost in blend with black coal, which is technologically viable. Moreover analyzed the problems of the authorization and operation of the co-combustion of sewage sludge and of combustion of products of various kinds of pyrolysis waste - pyrolysis gas and pyrolysis oil are analyzed. Copyright © 2017 Elsevier Ltd. All rights reserved.

Thermogravimetric analysis of combustible waste components

DEFF Research Database (Denmark)

Munther, Anette; Wu, Hao; Glarborg, Peter

In order to gain fundamental knowledge about the co-combustion of coal and waste derived fuels, the pyrolytic behaviors of coal, four typical waste components and their mixtures have been studied by a simultaneous thermal analyzer (STA). The investigated waste components were wood, paper, polypro......In order to gain fundamental knowledge about the co-combustion of coal and waste derived fuels, the pyrolytic behaviors of coal, four typical waste components and their mixtures have been studied by a simultaneous thermal analyzer (STA). The investigated waste components were wood, paper...

Assessing fly ash treatment: Remediation and stabilization of heavy metals

DEFF Research Database (Denmark)

Lima, A.T.; Ottosen, Lisbeth M.; Ribeiro, Alexandra B.

2012-01-01

Fly ashes from Municipal Solid Waste (MSW), straw (ST) and co-combustion of wood (CW) are here analyzed with the intent of reusing them. Two techniques are assessed, a remediation technique and a solidification/stabilization one. The removal of heavy metals from fly ashes through the electrodialy......Fly ashes from Municipal Solid Waste (MSW), straw (ST) and co-combustion of wood (CW) are here analyzed with the intent of reusing them. Two techniques are assessed, a remediation technique and a solidification/stabilization one. The removal of heavy metals from fly ashes through...

Fluidized bed combustion with the use of Greek solid fuels

Directory of Open Access Journals (Sweden)

Kakaras Emmanuel

2003-01-01

Full Text Available The paper is an overview of the results obtained up to date from the combustion and co-combustion activities with Greek brown coal in different installations, both in semi-industrial and laboratory scale. Combustion tests with Greek lignite were realized in three different Circulating Fluidized Bed Combustion (CFBC facilities. Low rank lignite was burned in a pilot scale facility of approx. 100kW thermal capacity, located in Athens (NTUA and a semi-industrial scale of 1.2 MW thermal capacity, located at RWE's power station Niederaussem in Germany. Co-combustion tests with Greek xylitic lignite and waste wood were carried out in the 1 MWth CFBC installation of AE&E, in Austria. Lab-scale co-combustion tests of Greek pre-dried lignite with biomass were accomplished in a bubbling fluidized bed in order to investigate ash melting problems. The obtained results of all aforementioned activities showed that fluidized bed is the appropriate combustion technology to efficiently exploit the low quality Greek brown coal either alone or in conjunction with biomass species.

Studying the melting behavior of coal, biomass, and coal/biomass ash using viscosity and heated stage XRD data

DEFF Research Database (Denmark)

Arvelakis, Stelios; Folkedahl, B.; Dam-Johansen, Kim

2006-01-01

by the cocombustion tests appeared to be somewhat different compared to that of the laboratory-prepared ash samples. The heated stage XRD data provide useful information regarding the reactions among the various ash compounds and the phase transformations during the heating and cooling of the ash samples and helped...... a high-temperature rotational viscometer and a hot stage XRD. The produced data were used to calculate the operating temperature of a pilot-scale entrained flow reactor during the cocombustion of biomass/ coal samples in order to ensure the slag flow and to avoid corrosion of the walls due to liquid slag...

Co-combustion of sewage sludge and energy-rich waste fuels or forest fuels; Sameldning av roetslam och energirika avfallsbraenslen eller skogsbraenslen

Energy Technology Data Exchange (ETDEWEB)

Linder, Kristina [TPS Termiska Processer AB, Nykoeping (Sweden)

2003-10-01

In this report literature on incineration of sewage sludge is summarises. In Sweden there is a yearly production of about 0,24 million-ton dry sewage sludge of which 50% is deposited. Recent changes in legislation will restrict and later prohibit the dumping of sewage sludge. Alternative methods for handling the material have not yet been found. In other parts of Europe the problem has been solved by incineration. Sludge incineration can be performed in several ways depending of the pretreatment. The sludge can be raw or digested, dewatered or dried. The sludge can be burnt as single fuel or in mixtures with other fuels. Focus in this work has been on co-combustion with biofuel or waste, as it will make use of existing plants. Digested sludge is also of major interest as 70% of the Swedish sludge is digested. The report describes the situation both in Sweden and in the rest of Europe. Sludge has a varying quality depending on origin and treatment, which affects the combustion properties. Ash and moisture contents differ from other fuels. The heating value of sewage sludge is approximately 20 MJ/kg per dry combustible matter and the amount of organic is around 70%. Compared to forest residue and demolition wood, sludge contains high levels of nitrogen and sulphur, which will cause emissions. The nitrogen level is about 10 times higher and the sulphur level 25 to 50 times higher. Sulphur, in combination with alkali metals, can cause deposit problems in boilers. However, sludge contains low levels of alkali. In the experimental investigation leaching of digested sludge showed low values on water conductivity which indicates a low concentration of sintering ash species in the sludge. A comparison of the aerodynamic properties of dried digested sludge and wood chips from energy coppice showed that sludge has a lower fraction of fines. This indicates that the sewage sludge is not likely to be carried over in the furnace but rather to stay in the fuel and ash bed on the

Recovered fuels - The connection between fuel preparation, combustion equipments and ash quality; Returbraenslen - kopplingen mellan braensleberedning, foerbraenningsutrustning och askkvalitet

Energy Technology Data Exchange (ETDEWEB)

Gyllenhammar, Marianne; Johansson, Inge [S.E.P. Scandinavian Energy Project AB, Goeteborg (Sweden)

2004-01-01

The lack of bio fuel and new regulations of waste treatment have increased the interest of recovered fuels. Co-combustion is of great interest, but the consequences and permit handling involved in introducing a new fuel into a plant have to be investigated. The aim of this study is to see if it is possible to affect the ash quality by pre-treatment of the fuel, or by firing in different combustion equipments. Ashes can be used in several different types of applications. Few of these have uniform requirements of ash quality. The ongoing research will hopefully help generating unified regulations and recommendations for the uses of ashes. However, right now the knowledge is limited and very specific. Every type of ash has to be analysed for the appropriate use. It is especially the requirements of leaching that are difficult to make general. The work started with a survey of recovered fuels. It contains roughly which fuels exist and which of those are accessible for the energy market in Sweden. The survey showed that there are approximately 13 Mton/y wastes partly accessible to the energy market; 50 % are used for material recycling, 32 % for energy recovery, 1.5 % for composting and the rest are used as landfill. Three recovered fuels were chosen and studied more thoroughly. These were PTP (paper, wood and plastic), tires and impregnated wood. The project showed that the recovered fuels have different qualifications as fuels and have different possibilities at co-combustion which results in variable ash quality. A pre-treated fuel is more homogeneous which give better combustion and cleaner ashes. A fluidised bed demands a more pre-treated fuel than a grate and the fluidised bed generate more ashes because the ashes contain bed material. As a result of this the ashes from a fluidised bed is generally easier to utilize. In this project the composition of ashes from co-combustion of the three recovered fuels together with wood fuel has been estimated. The aim was to

Combustion of agro-waste with coal in a fluidized bed

Energy Technology Data Exchange (ETDEWEB)

Atimtay, Aysel T. [Middle East Technical University, Department of Environmental Engineering, Ankara (Turkey)

2010-02-15

In this study, a review of the studies done on the co-combustion of some agro-waste in a bubbling fluidized bed combustor (BFBC) having an inside diameter of 102 mm and a height of 900 mm is given. The agro-waste used to investigate the co-combustion characteristics were peach and apricot stones produced as a waste from the fruit juice industry, and olive cake produced as a waste from the olive oil industry. These are typical wastes for a Mediterranean country. A lignite coal was used for co-combustion. On-line concentrations of O{sub 2}, CO, CO{sub 2}, SO{sub 2}, NO{sub x} and total hydrocarbons (C{sub m} H{sub n}) were measured in the flue gas during combustion experiments. Variations of emissions of various pollutants were studied by changing the operating parameters (excess air ratio, fluidization velocity and fuel feed rate). Temperature distribution along the bed was measured with thermocouples. Emissions were also monitored from the exhaust. Various combinations of coal and biomass mixtures were tested. During the combustion tests, it was observed that the volatile matter from the biomass quickly volatilizes and mostly burns in the freeboard. The temperature profiles along the bed and the freeboard also confirmed this phenomenon. It was found that as the volatile matter of the biomass increases, combustion takes place more in the freeboard region. Better combustion conditions occur at higher excess air ratios. The results showed that co-combustion with these three proposed biomasses lowers the SO{sub 2} and NO{sub x} emissions considerably. CO and hydrocarbon emissions are lower at the higher excess air ratios. (orig.)

BIOMASS UTILIZATION AS A RENEVABLE ENERGY SOURCE IN POLISH POWER INDUSTRY – CURRENT STATUS AND PERSPECTIVES

Directory of Open Access Journals (Sweden)

Beata Gołuchowska

2015-06-01

Full Text Available The depletion of the conventional energy sources, as well as the degradation and pollution of the environment by the exploitation of fossil fuels caused the development of renewable energy sources (RES, including biomass. In Poland, biomass is the most popular renewable energy source, which is closely related to the obligations associated with the membership in the EU. Biomass is the oldest renewable energy source, and its potential, diversity and polymorphism place it over other sources. Besides, the improvement in its parameters, including an increase in its calorific value, resulted in increasing use of biomass as energy source. In the electric power industry biomass is applied in the process of co-combustion with coal. This process may contribute, inter alia, to the reduction in the emissions of carbon, nitrogen and sulfur oxides. The article presents the characteristics of the biomass burned in power boilers of one of the largest Polish power plants, located in Opole Province (Southern Poland. Besides, the impact of biomass on the installation of co-combustion, as well as the advantages and disadvantages of the co-combustion process not only in technological, but also environmental, economic and social aspects were described.

Environmental considerations on the FBC combustion of dry sewage sludge

Energy Technology Data Exchange (ETDEWEB)

Lopes, M. Helena; Abelha, Pedro; Gulyurtlu, Ibrahim; Cabrita, Isabel [INETI/DEECA, Lisboa (Portugal)

2001-07-01

This paper presents results of on-going research on the incineration of pre-dried granular sewage sludges using a FBC system. Co-combustion is compared with mono-combustion of sludges leads to minor emissions and higher retention of Cd, Pb, Cu, and Zn in the bottom ashes, when compared to co-combustion with coal. The leachability of the sludge is reduced through combustion, as none of the metals, Cd, Cr, Ca Ni, Ph, Zn, Co and Mn were leached from the bottom ashes. These findings may contribute to an improvement in the incineration of sewage sludges and to the development of applications for the ashes in civil engineering activities.

ALTENER - Biomass event in Finland

Energy Technology Data Exchange (ETDEWEB)

NONE

1998-12-31

The publication contains the lectures held in the Biomass event in Finland. The event was divided into two sessions: Fuel production and handling, and Co-combustion and gasification sessions. Both sessions consisted of lectures and the business forum during which the companies involved in the research presented themselves and their research and their equipment. The fuel production and handling session consisted of following lectures and business presentations: AFB-NETT - business opportunities for European biomass industry; Wood waste in Europe; Wood fuel production technologies in EU- countries; new drying method for wood waste; Pellet - the best package for biofuel - a view from the Swedish pelletmarket; First biomass plant in Portugal with forest residue fuel; and the business forum of presentations: Swedish experiences of willow growing; Biomass handling technology; Chipset 536 C Harvester; KIC International. The Co-combustion and gasification session consisted of following lectures and presentations: Gasification technology - overview; Overview of co-combustion technology in Europe; Modern biomass combustion technology; Wood waste, peat and sludge combustion in Enso Kemi mills and UPM-Kymmene Rauma paper mill; Enhanced CFB combustion of wood chips, wood waste and straw in Vaexjoe in Sweden and Grenaa CHP plant in Denmark; Co-combustion of wood waste; Biomass gasification projects in India and Finland; Biomass CFB gasifier connected to a 350 MW{sub t}h steam boiler fired with coal and natural gas - THERMIE demonstration project in Lahti (FI); Biomass gasification for energy production, Noord Holland plant in Netherlands and Arbre Energy (UK); Gasification of biomass in fixed bed gasifiers, Wet cleaning and condensing heat recovery of flue gases; Combustion of wet biomass by underfeed grate boiler; Research on biomass and waste for energy; Engineering and consulting on energy (saving) projects; and Research and development on combustion of solid fuels

ALTENER - Biomass event in Finland

Energy Technology Data Exchange (ETDEWEB)

NONE

1997-12-31

The publication contains the lectures held in the Biomass event in Finland. The event was divided into two sessions: Fuel production and handling, and Co-combustion and gasification sessions. Both sessions consisted of lectures and the business forum during which the companies involved in the research presented themselves and their research and their equipment. The fuel production and handling session consisted of following lectures and business presentations: AFB-NETT - business opportunities for European biomass industry; Wood waste in Europe; Wood fuel production technologies in EU- countries; new drying method for wood waste; Pellet - the best package for biofuel - a view from the Swedish pelletmarket; First biomass plant in Portugal with forest residue fuel; and the business forum of presentations: Swedish experiences of willow growing; Biomass handling technology; Chipset 536 C Harvester; KIC International. The Co-combustion and gasification session consisted of following lectures and presentations: Gasification technology - overview; Overview of co-combustion technology in Europe; Modern biomass combustion technology; Wood waste, peat and sludge combustion in Enso Kemi mills and UPM-Kymmene Rauma paper mill; Enhanced CFB combustion of wood chips, wood waste and straw in Vaexjoe in Sweden and Grenaa CHP plant in Denmark; Co-combustion of wood waste; Biomass gasification projects in India and Finland; Biomass CFB gasifier connected to a 350 MW{sub t}h steam boiler fired with coal and natural gas - THERMIE demonstration project in Lahti (FI); Biomass gasification for energy production, Noord Holland plant in Netherlands and Arbre Energy (UK); Gasification of biomass in fixed bed gasifiers, Wet cleaning and condensing heat recovery of flue gases; Combustion of wet biomass by underfeed grate boiler; Research on biomass and waste for energy; Engineering and consulting on energy (saving) projects; and Research and development on combustion of solid fuels

An integrated appraisal of energy recovery options in the United Kingdom using solid recovered fuel derived from municipal solid waste.

Science.gov (United States)

Garg, A; Smith, R; Hill, D; Longhurst, P J; Pollard, S J T; Simms, N J

2009-08-01

This paper reports an integrated appraisal of options for utilising solid recovered fuels (SRF) (derived from municipal solid waste, MSW) in energy intensive industries within the United Kingdom (UK). Four potential co-combustion scenarios have been identified following discussions with industry stakeholders. These scenarios have been evaluated using (a) an existing energy and mass flow framework model, (b) a semi-quantitative risk analysis, (c) an environmental assessment and (d) a financial assessment. A summary of results from these evaluations for the four different scenarios is presented. For the given ranges of assumptions; SRF co-combustion with coal in cement kilns was found to be the optimal scenario followed by co-combustion of SRF in coal-fired power plants. The biogenic fraction in SRF (ca. 70%) reduces greenhouse gas (GHG) emissions significantly ( approximately 2500 g CO(2) eqvt./kg DS SRF in co-fired cement kilns and approximately 1500 g CO(2) eqvt./kg DS SRF in co-fired power plants). Potential reductions in electricity or heat production occurred through using a lower calorific value (CV) fuel. This could be compensated for by savings in fuel costs (from SRF having a gate fee) and grants aimed at reducing GHG emission to encourage the use of fuels with high biomass fractions. Total revenues generated from coal-fired power plants appear to be the highest ( 95 pounds/t SRF) from the four scenarios. However overall, cement kilns appear to be the best option due to the low technological risks, environmental emissions and fuel cost. Additionally, cement kiln operators have good experience of handling waste derived fuels. The scenarios involving co-combustion of SRF with MSW and biomass were less favourable due to higher environmental risks and technical issues.

An integrated appraisal of energy recovery options in the United Kingdom using solid recovered fuel derived from municipal solid waste

International Nuclear Information System (INIS)

Garg, A.; Smith, R.; Hill, D.; Longhurst, P.J.; Pollard, S.J.T.; Simms, N.J.

2009-01-01

This paper reports an integrated appraisal of options for utilising solid recovered fuels (SRF) (derived from municipal solid waste, MSW) in energy intensive industries within the United Kingdom (UK). Four potential co-combustion scenarios have been identified following discussions with industry stakeholders. These scenarios have been evaluated using (a) an existing energy and mass flow framework model, (b) a semi-quantitative risk analysis, (c) an environmental assessment and (d) a financial assessment. A summary of results from these evaluations for the four different scenarios is presented. For the given ranges of assumptions; SRF co-combustion with coal in cement kilns was found to be the optimal scenario followed by co-combustion of SRF in coal-fired power plants. The biogenic fraction in SRF (ca. 70%) reduces greenhouse gas (GHG) emissions significantly (∼2500 g CO 2 eqvt./kg DS SRF in co-fired cement kilns and ∼1500 g CO 2 eqvt./kg DS SRF in co-fired power plants). Potential reductions in electricity or heat production occurred through using a lower calorific value (CV) fuel. This could be compensated for by savings in fuel costs (from SRF having a gate fee) and grants aimed at reducing GHG emission to encourage the use of fuels with high biomass fractions. Total revenues generated from coal-fired power plants appear to be the highest ( Pounds 95/t SRF) from the four scenarios. However overall, cement kilns appear to be the best option due to the low technological risks, environmental emissions and fuel cost. Additionally, cement kiln operators have good experience of handling waste derived fuels. The scenarios involving co-combustion of SRF with MSW and biomass were less favourable due to higher environmental risks and technical issues.

Controlling the excess heat from oxy-combustion of coal by blending with biomass

Energy Technology Data Exchange (ETDEWEB)

Haykiri-Acma, H.; Turan, A.Z.; Yaman, S.; Kucukbayrak, S. [Istanbul Technical University, Chemical and Metallurgical Engineering Faculty, Chemical Engineering Department, 34469, Maslak, Istanbul (Turkey)

2010-11-15

Two different biomass species such as sunflower seed shell and hazelnut shell were blended with Soma-Denis lignite to determine the effects of co-combustion on the thermal reactivity and the burnout of the lignite sample. For this purpose, Thermogravimetric Analysis and Differential Scanning Calorimetry techniques were applied from ambient to 900 C with a heating rate of 40 C/min under dry air and pure oxygen conditions. It was found that the thermal reactivities of the biomass materials and the lignite are highly different from each other under each oxidizing medium. On the other hand, the presence of biomass in the burning medium led to important influences not only on the burnout levels but also on the heat flows. The heat flow from the burning of lignite increased fivefold when the oxidizing medium was altered from dry air to pure oxygen. But, in case of co-combustion under oxygen, the excess heat arising from combustion of lignite could be reduced and this may be helpful to control the temperature of the combustion chamber. Based on this, co-combustion of coal/biomass blends under oxygen may be suggested as an alternative method to the ''Carbon Dioxide Recycle Method'' encountered in the oxyfuel combustion systems. (author)

Co-Fuelling of Peat with Meat and Bone Meal in a Pilot Scale Bubbling Bed Reactor

Directory of Open Access Journals (Sweden)

Markku Orjala

2010-07-01

Full Text Available Co-combustion performance trials of Meat and Bone Meal (MBM and peat were conducted using a bubbling fluidized bed (BFB reactor. In the combustion performance trials the effects of the co-combustion of MBM and peat on flue gas emissions, bed fluidization, ash agglomeration tendency in the bed and the composition and quality of the ash were studied. MBM was mixed with peat at 6 levels between 15% and 100%. Emissions were predominantly below regulatory limits. CO concentrations in the flue gas only exceeded the 100 mg/m3 limit upon combustion of pure MBM. SO2 emissions were found to be over the limit of 50 mg/m3, while in all trials NOx emissions were below the limit of 300 mg/m3. The HCl content of the flue gases was found to vary near the limit of 30 mg/m3. VOCs however were within their limits. The problem of bed agglomeration was avoided when the bed temperature was about 850 °C and only 20% MBM was co-combusted. This study indicates that a pilot scale BFB reactor can, under optimum conditions, be operated within emission limits when MBM is used as a co-fuel with peat. This can provide a basis for further scale-up development work in industrial scale BFB applications.

Comparative environmental analysis of waste brominated plastic thermal treatments

International Nuclear Information System (INIS)

Bientinesi, M.; Petarca, L.

2009-01-01

The aim of this research activity is to investigate the environmental impact of different thermal treatments of waste electric and electronic equipment (WEEE), applying a life cycle assessment methodology. Two scenarios were assessed, which both allow the recovery of bromine: (A) the co-combustion of WEEE and green waste in a municipal solid waste combustion plant, and (B) the staged-gasification of WEEE and combustion of produced syngas in gas turbines. Mass and energy balances on the two scenarios were set and the analysis of the life cycle inventory and the life cycle impact assessment were conducted. Two impact assessment methods (Ecoindicator 99 and Impact 2002+) were slightly modified and then used with both scenarios. The results showed that scenario B (staged-gasification) had a potentially smaller environmental impact than scenario A (co-combustion). In particular, the thermal treatment of staged-gasification was more energy efficient than co-combustion, and therefore scenario B performed better than scenario A, mainly in the impact categories of 'fossil fuels' and 'climate change'. Moreover, the results showed that scenario B allows a higher recovery of bromine than scenario A; however, Br recovery leads to environmental benefits for both the scenarios. Finally the study demonstrates that WEEE thermal treatment for energy and matter recovery is an eco-efficient way to dispose of this kind of waste

Cocombustion of animal meal

International Nuclear Information System (INIS)

Roggen, M.

2001-01-01

The electricity production companies are prepared to co-fire animal meal in their coal-fired power stations. Tests conducted at the Maasvlakte power station, Netherlands, demonstrate that adding animal meal to the coal has no negative influence on human beings, the environment, the plant or the fly ash quality

Health effects of coal technologies: research needs

Energy Technology Data Exchange (ETDEWEB)

1980-09-01

In this 1977 Environmental Message, President Carter directed the establishment of a joint program to identify the health and environmental problems associated with advanced energy technologies and to review the adequacy of present research programs. In response to the President's directive, representatives of three agencies formed the Federal Interagency Committee on the Health and Environmental Effects of Energy Technologies. This report was prepared by the Health Effects Working Group on Coal Technologies for the Committee. In this report, the major health-related problems associated with conventional coal mining, storage, transportation, and combustion, and with chemical coal cleaning, in situ gasification, fluidized bed combustion, magnetohydrodynamic combustion, cocombustion of coal-oil mixtures, and cocombustion of coal with municipal solid waste are identified. The report also contains recommended research required to address the identified problems.

LCA Of The “Renescience” Concept: An Alternative To Incineration For The Treatment Of Residual Municipal Solid Waste

DEFF Research Database (Denmark)

Tonini, Davide; Astrup, Thomas

2010-01-01

The “REnescience” system consists on a pretreatment of the waste based on heat and enzymes which liquefy the biogenic fraction of the waste (paper and organics). The outputs of the process are then liquid slurry and a remaining solid fraction from which metals, plastic and glass can eventually...... be separated for recycling. In this study the environmental assessment of a number of scenarios for the “REnescience” concept is presented. The scenarios assessed are co-combustion of solid and liquid fraction in coal-fired power plants (CC-CC), co-combustion of the liquid fraction and incineration...... are mainly connected to metals recovery (around -12 mPE/tonne of ww). The results for the toxicity categories show that the “REnescience” options are more environmentally friendly with respect to ETwc because of the higher recycling but contribute with environmental loads on HTs and HTw because of potential...

[Effects of sulphur compounds on the volatile characteristics of heavy metals in fly ash from the MSW and sewage sludge co-combustion plant during the disposal process with higher temperature].

Science.gov (United States)

Liu, Jing-Yong; Sun, Shui-Yu

2012-11-01

Fly ash sample was collected from a MSW co-combustion with sewage sludge plant and the volatilization of heavy metals Pb, Cd, Cu and Zn was investigated before and after the water washing of fly ash, meanwhile, the influence of adding different sulphur compounds (S, NaS, Na2 SO3, Na2 SO4) on the volatilization of heavy metals was studied. The results showed that the contents of Zn, Pb and Mn were high, the Ni content was low and the Cd content reached 29.4 mg x kg(1). The contents of Pb, Cu, Zn increased, while that of Cd reduced in the fly ash after water washing. TG-DTG curves of fly ash showed highest weight loss in ranges of 579-732 degrees C and 949-1 200 degrees C, with 690 degrees C and 1 154 degrees C as the inflection point temperatures. The volatilization of different heavy metals showed great difference in the volatilization rate, following the order of Pb > Cd > Zn > Cu, in which the volatilization rate of Pb was more than 80% and that of Cu was less than 30%. After water washing, the volatilization of different heavy metals showed great difference in the volatilization rate, with the order of Zn > Pb > Cd > Cu, in which the volatilization rate of Zn was more than 20%. With the pretreatment of adding Na2 SO3 and Na2 SO4, the evaporation rates of heavy metals (Cu, Pb, Zn, Cd) were significantly decreased. After adding S, the evaporation rate of Zn was reduced, whereas the addition of Na2S reduced the evaporation rates of Cd and Zn. The evaporation rates of the four heavy metals were all reduced after adding Na2S in the washed fly ash. The evaporation rates of Cu and Zn were reduced with addition of S and Na2SO3 and the evaporation rate of Cd was reduced by adding the four sulfides. The results can provide a basis for the harmless disposal and maximized resource utilization and recycling of fly ash.

Viscosity of ashes from energy production and municipal solid waste handling: A comparative study between two different experimental setups

DEFF Research Database (Denmark)

Arvelakis, Stelios; Frandsen, Flemming; Folkedahl, B.

2008-01-01

This paper discusses the viscosity characteristics of ash fractions produced from the co-combustion of coal and biomass in a pilot-scale pulverized fuel (PF) boiler and from the incineration of municipal solid waste (MSW) in a Danish incinerator that were determined using the high...

PSO Project 10085

DEFF Research Database (Denmark)

Jappe Frandsen, Flemming; Wu, Hao; Glarborg, Peter

Co-combustion of refuse derived fuels (RDF) with coal in pulverized coal-fired power plants can potentially increase the electrical efficiency of utilizing RDF and reduce the formation of some harmful pollutants such as dioxins. The objective of this project was to provide a general assessment of...

Thermogravimetric investigation on characteristic of biomass combustion under the effect of organic calcium compounds.

Science.gov (United States)

Zhang, Lihui; Duan, Feng; Huang, Yaji

2015-01-01

Experiments were conducted in a thermogravimetric analyzer to investigate thermal behavior of different organic calcium compounds (OCCs) and its blended fuels with three kinds of biomass. The effectiveness of synthesized method for OCC was assessed by the pyrolysis test. Effect of the mole ratio of calcium to sulfur on co-combustion characteristics was studied. Results indicated that preparation method of modified calcium acetate (MCA) had high precision and accuracy. Co-combustion characteristic of OCCs blended with biomass was controlled by OCCs' additive amount and the content of volatile matter which is mainly composed of small hydrocarbon molecules. Combustion performance indexes for peanut shell and wheat straw impregnated by OCCs were improved, however, an inverse trend was found for rice husk because of lower additive amount of OCCs. The blended fuel show higher combustion performance indexes compared with combustion of individual biomass, and these indexes decrease with increases of Ca/S ratio. Copyright © 2014 Elsevier Ltd. All rights reserved.

Energy implications of mechanical and mechanical–biological treatment compared to direct waste-to-energy

DEFF Research Database (Denmark)

Cimpan, Ciprian; Wenzel, Henrik

2013-01-01

achieved the highest savings, on the condition of SRF co-combustion. As a sensitivity scenario, alternative utilisation of SRF in cement kilns was modelled. It supported similar or higher net savings for all pre-treatment systems compared to mass combustion WtE, except when WtE CHP was possible...

The emissions of SO{sub 2}, NOx, PM, trace elements and other HAPS of coal-fired power stations in the Netherlands

Energy Technology Data Exchange (ETDEWEB)

R. Meij; B.H. Te Winkel [KEMA Power Generation & Sustainables, Arnhem (Netherlands)

2003-07-01

The emission limit values for coal-fired power stations in the European community and the Netherlands are described and compared in this paper. These limits are discussed in relation to the daily emissions in practice. Most attention is paid to heavy metals and other HAPS. The KEMA TRACE MODEL{reg_sign} can predict these elements fate. It is based on 25 years of research and predicts the distribution of elements over bottom ash, ESP ash, gypsum, emitted flue gases, sludge and effluent of the wastewater treatment plant. Next to this it predicts the composition of ash and flue gases. Wet FGD is the cause of a non-relation between the fuel composition and the emission into air for nearly most elements, except for some volatile elements (boron, bromine, chlorine, fluorine, mercury, iodine, sulphur and selenium). Although the emissions of these volatile elements are low, the concentrations are measured frequently, with emphasis on mercury, chlorine and fluorine. The consequences of co-combustion on emissions into air and the quality of by-products are discussed. The KEMA TRACE MODEL incorporates complicated EU regulations regarding co-combustion (the EU Waste Incineration Directive and the European Waste Catalogue). Modern coal-fired power stations in the Netherlands equipped with high-efficiency ESPs, wet FGD units and some with SCR meet the stringent present Dutch limits. Moreover, the quality of the by-products was such that a 100% of these by-products are sold as building materials. The increasing percentage of co-combustion hardly influences the emissions into air. However, more effort is necessary to maintain the quality of the by-products, but they can still be fully applied.

Optimal utilization of waste-to-energy in an LCA perspective.

Science.gov (United States)

Fruergaard, T; Astrup, T

2011-03-01

Energy production from two types of municipal solid waste was evaluated using life cycle assessment (LCA): (1) mixed high calorific waste suitable for production of solid recovered fuels (SRF) and (2) source separated organic waste. For SRF, co-combustion was compared with mass burn incineration. For organic waste, anaerobic digestion (AD) was compared with mass burn incineration. In the case of mass burn incineration, incineration with and without energy recovery was modelled. Biogas produced from anaerobic digestion was evaluated for use both as transportation fuel and for heat and power production. All relevant consequences for energy and resource consumptions, emissions to air, water and soil, upstream processes and downstream processes were included in the LCA. Energy substitutions were considered with respect to two different energy systems: a present-day Danish system based on fossil fuels and a potential future system based on 100% renewable energy. It was found that mass burn incineration of SRF with energy recovery provided savings in all impact categories, but co-combustion was better with respect to Global Warming (GW). If all heat from incineration could be utilized, however, the two alternatives were comparable for SRF. For organic waste, mass burn incineration with energy recovery was preferable over anaerobic digestion in most impact categories. Waste composition and flue gas cleaning at co-combustion plants were critical for the environmental performance of SRF treatment, while the impacts related to utilization of the digestate were significant for the outcome of organic waste treatment. The conclusions were robust in a present-day as well as in a future energy system. This indicated that mass burn incineration with efficient energy recovery is a very environmentally competitive solution overall. Copyright © 2010 Elsevier Ltd. All rights reserved.

Ash and heavy metals in fluidized-bed combustion of wood wastes; Tuhka ja raskasmetallit puuperaeisen jaetteen kerrosleijupoltossa

Energy Technology Data Exchange (ETDEWEB)

Kaessi, T; Aittoniemi, P [IVO Power Engineering, Vantaa (Finland); Kauppinen, E; Latva-Somppi, J; Kurkela, J [VTT Chemical Technology, Espoo (Finland); Partanen, J [IVO Technology Centre, Vantaa (Finland)

1997-10-01

Ash formation and deposition mechanisms during co-combustion of pulp mill sludge and bark in industrial bubbling fluidized bed (BFB) combustor have been studied. Similar fuels were used in a bench-scale BFB for co-combustion of sludge and bark pellets and comparative studies with separate combustion of these fuels. Results indicated that in industrial scale unit significant fraction of ash had vaporization. About 14 mass-% of the total fly ash was found in the particle size below 0.2 {mu}m. The vaporized species consisted of potassium (K), sulfur (S), chlorine (Cl) and also of minor quantities of sodium (Na). In the benchscale similar vaporization fractions during co-combustion were measured, about 11 mass-%. During the combustion of bark this ratio, about 20 mass-%, was higher than during sludge combustion. The vaporized ash fraction was in the case of dried sludge combustion about 7 mass-%, but with wet sludge the vaporization rate was remarkably lower, about 1-2 mass-%. An increase in the bed temperature increased also ash vaporization. Test run period without combustion at elevated temperatures produced very low quantities of vaporized ash. The vaporized species in bench-scale test during bark pellet combustion were K, S and Cl, for sludge combustion also Na was clearly detected. No condensation of the vaporized species in bed area or furnace walls was observed. Bed defluidization was studied in the bench-scale unit. During bark pellet combustion the bed-agglomeration proceeded via small ash particle, below 2 {mu}m, coating on sand particle surface and consequent bonding between the ash layers. In the case of sludge combustion the accumulation of large ash particles and sintering of these porous agglomerates was observed to cause bed coarsening and defluidization. (orig.)

SCR in biomass and waste fuelled plants. Benchmarking of Swedish and European plants; SCR i biobraensle- och avfallseldade anlaeggningar. Erfarenheter fraan svenska och europeiska anlaeggningar

Energy Technology Data Exchange (ETDEWEB)

Goldschmidt, Barbara; Olsson, Henrik; Lindstroem, Erica

2010-11-15

In this report the state-of-art of SCR technology in biomass and waste fired plants is investigated. The aim of the investigation is to answer the question why new Swedish biomass combustion and co-combustion plants often prefer SNCR technology, whilst European waste combustion plants often choose SCR technology. In the report positives and negatives of various types of SCR installations are discussed, high-dust versus tail-end, 'normal' SCR versus low-temperature SCR, etc. Experiences, e g catalyst lifetime, deactivation and maintenance requirement, are discussed. The investigation is based partly on literature, but mainly on interviews with plant owners and with suppliers of SCR installations. The interviewed suppliers are mentioned in the reference list and the interviewed plant owners are mentioned in appendix A and B. The experiences from the Swedish and European plants are quite similar. Tail-end SCR is often operated without serious problems in both biomass and waste fuelled plants. The catalyst lifetimes are as long or even longer than for coal fired plants with high-dust SCR. In waste incineration plants high-dust SCR causes big problems and these plants are almost always equipped with tail-end SCR. In co-combustion boilers, where coal and biomass is co-combusted, high-dust SCR is more common, especially if the boilers were originally coal fired. In plants with both SNCR and high-dust SCR, i.e. slip-SCR, the SCR installation is considered to be much less of a problem. Although the activity loss of the catalyst is as quick as in conventional high-dust SCR, the catalyst can be changed less often. This is due to the fact that installed slip-SCR catalysts often are as large as conventional SCR catalysts, although less NO{sub x} reduction is required after the initial SNCR step. Thus, the catalyst lifetime is prolonged.

Optimization of use of waste in the future energy system

International Nuclear Information System (INIS)

Muenster, Marie; Meibom, Peter

2011-01-01

Alternative uses of waste for energy production become increasingly interesting when considered from two perspectives, that of waste management and the energy system perspective. This paper presents the results of an enquiry into the use of waste in a future energy system. The analysis was performed using the energy system analysis model, Balmorel. The study is focused on Germany and the Nordic countries and demonstrates the optimization of both investments and production within the energy systems. The results present cost optimization excluding taxation concerning the use of waste for energy production in Denmark in a 2025 scenario with 48% renewable energy. Investments in a range of waste conversion technologies are facilitated, including waste incineration, co-combustion with coal, anaerobic digestion, and gasification. The most economically feasible solutions are found to be incineration of mixed waste, anaerobic digestion of organic waste, and gasification of part of the potential RDF (refuse derived fuel) for CHP (combined heat and power) production, while the remaining part is co-combusted with coal. Co-combustion mainly takes place in new coal-fired power plants, allowing investments to increase in comparison with a situation where only investments in waste incineration are allowed. -- Highlights: → The analysis is based on hourly chronological time steps, thereby taking dynamic properties of the energy system into account. → The system analyzed includes both the heat and the electricity market, which is important when analyzing e.g. CHP technologies. → The surrounding countries, which form part of the same electricity market, are included in the analysis. → New innovative Waste-to-Energy production plants have been modeled to allow for a more efficient and flexible use of waste. → The analysis includes economical optimization of operation and of investments in production and transmission of both electricity and heat.

Characterization of fly ash from bio and municipal waste

DEFF Research Database (Denmark)

Lima, Ana T.; Ottosen, Lisbeth M.; Pedersen, Anne Juul

2008-01-01

the co-combustion of wood and oil. The focus is laid on differences in ash characteristics and on the mobility of Cd and Cr. These two heavy metals are chosen because Cd is the problematic heavy metal in bio ashes and Cr is problematic in many ash stabilization methods (in the Cr(VI) state). Based...

Energetic utilization of Solid Recovered Fuels with wood chips in a stoker-fired furnace; Energetische Nutzung von Solid Recovered Fuels mit Holzhackschnitzeln in einer Rostfeuerung

Energy Technology Data Exchange (ETDEWEB)

Nowak, Piotr; Gehrmann, Hans-Joachim; Seifert, Helmut; Pfrang-Stotz, Gudrun; Paur, Hanns-Rudolf [Karlsruher Institut fuer Technologie (KIT), Eggenstein-Leopoldshafen (Germany). Inst. fuer Technische Chemie (ITC); Schubert, Stefanie [TOMRA Sorting Solutions, Muelheim-Kaerlich (Germany). Test Facility Recycling TITECH; Glorius, Thomas [Remondis GmbH, Region Rheinland, Erftstadt (Germany). Stoffstrommanagement

2013-03-01

Very often, in Germany biofuels are utilized energetically in a pure energetic mode predominantly in EEG incinerator plants. Further clear increases of efficiencies only are possible within a cocombustion in power plant processes with enhanced vapour parameters or in cogeneration power plants, respectively. In the course of an international collaborative project, first experiments at demonstration scale at two fluidized bed boilers at the power plant Wachtberg (Frechen, Federal Republic of Germany) it could be shown, that alternative fuels with an enhanced amount of biomass can be cocombusted without disadvantageous impacts on the emissions. The addition of sulphur to the mono-combustion of biofuels and substitute fuels reduced the total amount of chlorine. But the addition of sulphur also resulted in clearly harder coverings in waste heat recovery boilers by means of the formation of anhydrite as well as to an enhanced dust loading. The substitute fuel online analysis system from TOMRA Sorting Solutions (Wedel/Hamburg, Federal Republic of Germany) was installed in front of the stoker-fired furnace for the online-monitoring of the operation parameters chlorine, water and calorific value.

Energy recovery of combustible fraction from shredding of wastes containing metals; Energiaatervinning av braennbar fraktion fraan fragmentering av metallhaltigt avfall

Energy Technology Data Exchange (ETDEWEB)

Gyllenhammar, Marianne [Stena Metall, Goeteborg (Sweden); Victoren, Anders; Niemi, Jere [Metso Power, Tammerfors (Finland); Johansson, Andreas [SP Technical Research Inst. of Sweden, Boraas (Sweden)

2009-01-15

Combustible products from fragmentation are not allowed to be deposited on landfills any more in Sweden. These products have to be material recovered or energy recovered. The combustible fraction from recovered metal scrap, SLF (shredder light fraction), contains metals and the chlorine content is relatively high. Due to this there could be a risk with deposits and corrosion on convection surfaces in combustion plants. Co-combustion with sewage sludge could be a solution for solving problems with the difficult contents in SLF. The aim of the project was to do a theoretical judgment of how sewage sludge could affect deposit formation and corrosion when co-combusted with SLF. Due to the high amount of water in the sewage sludge the percentage of sewage sludge in the fuel mixture was limited. The maximum percentage of energy used was 3.5 % (ca 13% on weight basis). The thermodynamic calculations showed that at combustion with 100% SLF the lead and zinc chlorides in gaseous form increased 5-6 times in comparative with combustion with ordinary waste combustion in Boraas. But as the thermodynamic equilibrium calculations will not consider the kinetics and just calculate independent of time the results should be considered as indicative and not directly comparative to actual boiler conditions. All lead and zinc were assumed reactive which will probably not be the case in a boiler. In the calculations the aluminum was removed from the calculations (not taken into account) and the alkali-phosphor reactions are incomplete due to lack of reliable thermodynamic data. These defiance's should be considered when evaluating the results from the thermodynamic chemical equilibrium calculations as well as the fact that the calculations cannot yet take into account the possible erosive effect the high ash amount could have on the deposits. The calculations showed that co-combusting with SLF (ca 20%) gave high amounts of gaseous lead chlorides. Also high amount of zinc chlorides

N2O emission under fluidized bed combustion condition

International Nuclear Information System (INIS)

Shen, B.X.; Yao, Q.; Mi, T.; Liu, D.C.; Feng, B.; Winter, Franz

2003-01-01

In this paper, many rules about N 2 O and NO x emission under fluidized bed combustion conditions were found by experiments. The research results indicate that CaO, CaSO 4 , Fe 2 O 3 and char have important influence on decomposition of N 2 O; co-combustion of coal and biomass are effective measures to low N 2 O and NO x emission

The importance of energetic utilization is increasing; Energetische Verwertung waechst

Energy Technology Data Exchange (ETDEWEB)

Briese, Dirk; Meyer, Christian [trend:research GmbH, Institut fuer Trend- und Marktforschung, Bremen (Germany)

2010-04-15

In spite of uniform standards and regulations, sewage treatment strategies of the European states differ dramatically. A current study shows that thermal treatment in monocombustion or cocombustion plants is increasingly important. Forecasts of the trend:research trend and marketing research institute, energetic utilization will become the dominant utilization strategy in Europe, with a share that will have increase by about 50 percent by 2020. (orig.)

The study of partitioning of heavy metals during fluidized bed combustion of sewage sludge and coal

Energy Technology Data Exchange (ETDEWEB)

Gulyurtlu, I.; Lopes, M.H.; Abelha, P.; Cabrita, I.; Oliveira, J.F.S. [INETI, Lisbon (Portugal)

2006-06-15

The behavior of Cd, Cr, Cu, Co, Mn, Ni, Pb, Zn, and Hg during the combustion tests of a dry granular sewage sludge on a fluidized bed combustor pilot (FBC) of about 0.3 MW was evaluated. The emissions of these heavy metals from mono-combustion were compared with those of co-combustion of the sludge with a bituminous coal. The effect of the addition of limestone was also studied in order to retain sulphur compounds and to verify its influence on the retention of heavy metals (HM). Heavy metals were collected and analyzed from different locations of the installation, which included the stack, the two cyclones, and the material removed from the bed. The results showed that the volatility of metals was rather low, resulting in emissions below the legal limits of the new directive on incineration, with the exception of Hg during the mono-combustion tests. The partitioning of metals, except for Hg, appeared to follow that of ashes, amounting to levels above 90% in the bed streams in the mono-combustion case. For co-combustion, there was a lower fixation of HM in the bed ashes, mostly originating essentially from the sewage sludge, ranging between 40% and 80%. It is believed that in this latter case, a slightly higher temperature could have enhanced the volatilization, especially of Cd and Pb. However these metals were then retained in fly ashes captured in the cyclones. In the case of Hg, the volatilisation was complete. The bed ashes were free of Hg and part of Hg was retained in the cyclones and the rest was emitted either with fine ash particles or in gaseous forms. In mono-combustion the Hg emissions from the stack (particles and gas) accounted, for about 50%. This appeared to have significantly decreased in the case of co-combustion, as only about 75% has been emitted, due to the retention effect of cyclone ashes.

The study of partitioning of heavy metals during fluidized bed combustion of sewage sludge and coal

Energy Technology Data Exchange (ETDEWEB)

Gulyurtlu, Ibrahim; Lopes, M. Helena; Abelha, Pedro; Cabrita, Isabel; Oliveira, J.F. Santos

2003-07-01

The behaviour of Cd, Cr, Cu, Co, Mn, Pb, Zn and Hg during the combustion tests of granular dry sewage sludges on a pilot FBC of about 0,3 MW was evaluated. The emissions of these heavy metals from mono-combustion were compared with those of co-combustion of the sludge with a bituminous coal. The effect of the addition of limestone was also studied in order to retain sulphur compounds and to verify its influence on the retention of heavy metals. Heavy metals were collected and analysed from different locations of the installation, which included the stack, the two cyclones and the material removed from the bed. The results showed that the volatility of metals was rather low, resulting in emissions below the legal limits of the new directive on incineration, with the exception of Hg during the mono-combustion tests. The partitioning of metals, except for Hg, appeared to follow that of ashes, amounting to levels above 90% in the bed streams in the mono-combustion case. For co-combustion, there was a lower fixation of HM in the bed ashes, mostly originating essentially from the sewage sludge, ranging between 40 and 80%. It is believed that in this latter case, a slightly higher bed temperature could have enhanced the volatilisation, especially of Cd and Pb. However these metals were then retained in cyclone ashes. In the case of Hg, the volatilisation was complete. The bed ashes were free of Hg and part of it was retained in the cyclone and emitted as both fine ash particles and in gaseous forms. In mono-combustion the Hg emissions from the stack (particles and gas) accounted for about 50%, although there was a significant amount unaccounted for. This appeared to have significantly decreased in the case of co-combustion, as only about 15% has been emitted, due to the retention effect of cyclone ashes which presented high quantities of unburned carton and possibly condensed sulphur species.

Effect of biomass on burnouts of Turkish lignites during co-firing

Energy Technology Data Exchange (ETDEWEB)

Haykiri-Acma, H.; Yaman, S. [Istanbul Technical Univ., Chemical and Metallurgical Engineering Faculty, Chemical Engineering Dept., 34469 Maslak, Istanbul (Turkey)

2009-09-15

Co-firing of some low quality Turkish lignites with woody shells of sunflower seed was investigated via non-isothermal thermogravimetric analysis method. For this purpose, Yozgat-Sorgun, Erzurum-Askale, Tuncbilek, Gediz, and Afsin-Elbistan lignites were selected, and burnouts of these lignites were compared with those of their blends. Biomass was blended as much as 10 and 20 wt.% of the lignites, and heating was performed up to 900 C at a heating rate of 40 C/min under dry air flow of 40 mL/min. This study revealed that the same biomass species may have different influences on the burnout yields of the lignites. Burnouts of Erzurum-Askale lignite increased at any temperature with the increasing ratio of biomass in the blend, whereas burnout yields of other lignites decreased to some extent. Nevertheless, the blends of Turkish lignites with sunflower seed shell did not behave in very different way, and it can be concluded that they are compatible in terms of burnouts for co-combustion in a combustion system. Although the presence of biomass in the lignite blends caused to some decreases in the final burnouts, the carbon dioxide neutral nature of biomass should be taken into account, and co-combustion is preferable for waste-to-energy-management. (author)

Effect of biomass on burnouts of Turkish lignites during co-firing

International Nuclear Information System (INIS)

Haykiri-Acma, H.; Yaman, S.

2009-01-01

Co-firing of some low quality Turkish lignites with woody shells of sunflower seed was investigated via non-isothermal thermogravimetric analysis method. For this purpose, Yozgat-Sorgun, Erzurum-Askale, Tuncbilek, Gediz, and Afsin-Elbistan lignites were selected, and burnouts of these lignites were compared with those of their blends. Biomass was blended as much as 10 and 20 wt.% of the lignites, and heating was performed up to 900 deg. C at a heating rate of 40 deg. C/min under dry air flow of 40 mL/min. This study revealed that the same biomass species may have different influences on the burnout yields of the lignites. Burnouts of Erzurum-Askale lignite increased at any temperature with the increasing ratio of biomass in the blend, whereas burnout yields of other lignites decreased to some extent. Nevertheless, the blends of Turkish lignites with sunflower seed shell did not behave in very different way, and it can be concluded that they are compatible in terms of burnouts for co-combustion in a combustion system. Although the presence of biomass in the lignite blends caused to some decreases in the final burnouts, the carbon dioxide neutral nature of biomass should be taken into account, and co-combustion is preferable for waste-to-energy-management.

Study of boron behaviour in two Spanish coal combustion power plants.

Science.gov (United States)

Ochoa-González, Raquel; Cuesta, Aida Fuente; Córdoba, Patricia; Díaz-Somoano, Mercedes; Font, Oriol; López-Antón, M Antonia; Querol, Xavier; Martínez-Tarazona, M Rosa; Giménez, Antonio

2011-10-01

A full-scale field study was carried out at two Spanish coal-fired power plants equipped with electrostatic precipitator (ESP) and wet flue gas desulfurisation (FGD) systems to investigate the distribution of boron in coals, solid by-products, wastewater streams and flue gases. The results were obtained from the simultaneous sampling of solid, liquid and gaseous streams and their subsequent analysis in two different laboratories for purposes of comparison. Although the final aim of this study was to evaluate the partitioning of boron in a (co-)combustion power plant, special attention was paid to the analytical procedure for boron determination. A sample preparation procedure was optimised for coal and combustion by-products to overcome some specific shortcomings of the currently used acid digestion methods. In addition boron mass balances and removal efficiencies in ESP and FGD devices were calculated. Mass balance closures between 83 and 149% were obtained. During coal combustion, 95% of the incoming boron was collected in the fly ashes. The use of petroleum coke as co-combustible produced a decrease in the removal efficiency of the ESP (87%). Nevertheless, more than 90% of the remaining gaseous boron was eliminated via the FGD in the wastewater discharged from the scrubber, thereby causing environmental problems. Copyright © 2011 Elsevier Ltd. All rights reserved.

Energy from waste by gasification; Energi ur avfall genom foergasning

Energy Technology Data Exchange (ETDEWEB)

Padban, Nader; Nilsson, Torbjoern; Berge, Niklas [TPS Termiska Processer AB, Nykoeping (Sweden)

2002-12-01

At present the investigation on alternative techniques to solve the problem with the growing amount of the wastes within European countries is a highly propitiated research area. The driving forces behind this priority are the current EU-legislations regarding the ban on landfill of combustible wastes and also the regulation on emission limits from waste treatment plants. The alternatives for waste treatment besides recycling are incineration, direct co-combustion and gasification. Co-combustion of waste with biomass can be considered a short-term solution for the problem but has the disadvantages of decreasing the capacity for clean fuels such as biomass and set demands on intensive modifications in the existing heat or heat and power plants. Waste gasification is an attractive alternative that can compete with incineration and co-combustion processes when the environmental and economical aspects are concerned. The product gas from a waste gasifier can be burned alone in conventional oil fired boilers or be co-fired with biomass in biomass plant. Fuel quality, gas cleaning system and questions related to ash treatment are the key parameters that must be considered in design and construction of a waste gasification process. Gasification of waste fractions that have limited contents of contaminants such as nitrogen, sulfur and chlorine will simplify the gas cleaning procedure and increase the competitiveness of the process. Heavy metals will be in captured in the fly ash if a gas filtering temperature below 200 deg C is applied. Activated carbon can be used as a sorbent for mercury, lime or alkali for capturing chlorine. For fuels with low Zn content a higher gas filtering temperature can be applied. Direct co-combustion or gasification/co-combustion of a fuel with low heating value affects two main parameters in the boiler: the adiabatic combustion temperature and the total capacity of the boiler. It is possible to co-fire: a) sorted MSW: 25%, b) sorted industrial

Long term effects on wet stored calcium rich fly ash with bearing on ground improvement work; Laangtidspaaverkan av kalkrika flygaskor vid vaatlagring foer anvaendning inom markstabilisering

Energy Technology Data Exchange (ETDEWEB)

Lagerlund, Johan; Jansing, Christiane

2012-02-15

Generation of electricity and heat by means of thermal power demands a product that can be ignited. This combustible material is usually coal, oil, gas, biomass and waste. If using solid fuels as coal, biomass and waste a by product known as ash is formed in the process; FA, (FA) and bottom ash. Roughly 600 Mt ashes are annually produced throughout the world and 70 weight % of these ashes are FA, 25 weight % bottom ashes and 5 weight % slag. 41 weight % of all ashes are annually reused in some form. Given the environmental impact of combustion i.e. CO{sub 2} emissions, a widened use of biomass fuels and co-combustion is expected in the near future. This will however create new problems when reusing ashes and FA in particular. The reuse of FA within the concrete industry stand for a total of about 25 % but the reuse of non-coal derived FA in the concrete industry is prohibited. Non-coal derived FA usually has higher amounts of calcium oxide, which acts expansively in concrete. Less than 20 % of biomass or co-combustion FA are reused today in Europe. A new standard, the EN 450, is however under construction. This standard will deal with the reuse of noncoal derived FA within the cement and concrete industry. In Sweden, coal is very seldom used as a fuel. More common is the use of biomass, peat and waste. It means that the FA are all non-coal derived and thus derived from reuse within the cement and concrete industry. Beside their non-coal origin, the main part of the FA is produced during November- March. This means that it might be hard to find available FA all year around, making the reuse of FA less attractive. Hence, FA must be stored prior to use. Little research have been made on the storage of calcium rich FA from biomass and co-combustion. Storing FA in a cheap way requires an addition of water to prevent from dusting when stockpiled outdoors. Addition of water in calcium rich FA will however cause an hardening of the material, thus causing detrimental

Assessment of chemical and material contamination in waste wood fuels--A case study ranging over nine years.

Science.gov (United States)

Edo, Mar; Björn, Erik; Persson, Per-Erik; Jansson, Stina

2016-03-01

The increased demand for waste wood (WW) as fuel in Swedish co-combustion facilities during the last years has increased the import of this material. Each country has different laws governing the use of chemicals and therefore the composition of the fuel will likely change when combining WW from different origins. To cope with this, enhanced knowledge is needed on WW composition and the performance of pre-treatment techniques for reduction of its contaminants. In this study, the chemical and physical characteristics of 500 WW samples collected at a co-combustion facility in Sweden between 2004 and 2013 were investigated to determine the variation of contaminant content over time. Multivariate data analysis was used for the interpretation of the data. The concentrations of all the studied contaminants varied widely between sampling occasions, demonstrating the highly variable composition of WW fuels. The efficiency of sieving as a pre-treatment measure to reduce the levels of contaminants was not sufficient, revealing that sieving should be used in combination with other pre-treatment methods. The results from this case study provide knowledge on waste wood composition that may benefit its management. This knowledge can be applied for selection of the most suitable pre-treatments to obtain high quality sustainable WW fuels. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.

Residue Derived Fuels as an Alternative Fuel for the Hellenic Power Generation Sector and their Potential for Emissions ReductionConstantinos S. Psomopoulos

Directory of Open Access Journals (Sweden)

Constantinos S. Psomopoulos

2014-09-01

Full Text Available The European Union Landfill Directive (1999/31 EC promotes more environmental friendly waste management options, by reducing the amount of wastes and more specific of biodegradable wastes, disposed of in landfills. The EU member states are adopting the mechanical-biological treatment process for municipal solid waste and non-hazardous industrial wastes to comply with the abovementioned Directive's targets on landfill diversion, and produce waste derived fuels such as refuse derived fuel and solid recovered fuel. Waste derived fuels present high calorific values depending on their synthesis and are being used both in dedicated waste-to-energy plants and as fuel substitutes in industrial processes. In this paper the refuse derived fuel and solid recovered fuel production and utilisation options in European Union are presented, and the possibilities in Greece based on the waste production and National Plan for Waste Management of the Ministry of Environment is attempted. The existing and ongoing studies on co-combustion and co-gasification with brown coal support the use of refuse derived fuel and solid recovered fuel as fuel on Hellenic Power Sector, adopting in the existing lignite power plants adequate Air Pollution Control systems. If the co-combustion or co-gasification of these alternative fuels is adopted from the Hellenic Power Sector a reduction on emissions is expected that cannot be neglected.

Ash chemistry and behavior in advanced co-combustion

Energy Technology Data Exchange (ETDEWEB)

Hupa, M; Skrifvars, B J [Aabo Akademi, Turku (Finland). Combustion Chemistry Research Group

1997-10-01

The purpose of this LIEKKI 2 project is to report results achieved within the EU/JOULE/OPTEB project to the Finnish combustion research community through the LIEKKI program. The purpose of the EU/JOULE/OPTEB project is to find prediction methods for evaluating ash behavior, such as slagging, fouling and corrosion propensity, in full scale combustion systems through chemical or mineralogical analyses, intelligent laboratory tests and chemistry calculations. The project focuses on coals, coal mixtures and coal biomass mixtures fired in advanced combustion systems, such as fluidized bed boilers, pulverized fuel boilers with critical steam values etc. The project will make use of (1) advanced multi-component combustion equilibrium calculations, (2) ash sintering tendency laboratory tests and (3) chemical evaluations of slagging, fouling and corrosion measurements in full scale units. (orig.)

Circulating fluidized-bed technology - toward zero CO{sub 2} emissions

Energy Technology Data Exchange (ETDEWEB)

Timo Jaentti; Timo Eriksson; Arto Hotta; Timo Hyppaenen; Kalle Nuortimo [Foster Wheeler Energia Oy, Varkaus (Finland)

2006-07-01

This paper presents the existing status of CFB technology in respect of boiler efficiency and fuel flexibility. Examples of the high efficiency repowering CFB projects both with sub and supercritical steam parameters from Estonia (Narva) and Poland (Turow and Lagisza) are presented. The paper also describes experiences from one utility CFB project in Thailand (NPS) with high biofuel and coal cocombustion capability. The main advantages of the CFB technology for oxycombustion and a development plan for the Oxy CFB is presented. 11 refs., 11 figs., 3 tabs.

Strategies for enhancing the co-removal of mercury in FGD-scrubbers of power plants. Operating parameters and additives

Energy Technology Data Exchange (ETDEWEB)

Schuetze, Jan; Koeser, Heinz [Magdeburg Univ. (Germany). Chair of Environmental Technology; Halle-Wittenberg Univ., Halle (Germany). Centre of Engineering Services

2012-07-01

Co-combustion of waste fuels, coals with variable mercury content and lower regulatory emission limits are drivers for the optimisation of the co-removal of mercury in flue gas desulphurisation (FGD) scrubbers. The paper explains some new features of the system performance of FGD scrubbers for the co-removal of mercury in coal-fired power plants. Results on their efficiency under standardised laboratory conditions are presented. The effect of these measures on the quality of the FGD by-product gypsum will be covered as well. (orig.)

Strategies to reduce gaseous KCl and chlorine in deposits during combustion of biomass in fluidised bed boilers

Energy Technology Data Exchange (ETDEWEB)

Kassman, Haakan

2012-11-01

Combustion of a biomass with an enhanced content of alkali and chlorine (Cl) can result in operational problems including deposit formation and superheater corrosion. The strategies applied to reduce such problems include co-combustion and the use of additives. In this work, measures were investigated in order to decrease the risk of superheater corrosion by reducing gaseous KCl and the content of chlorine in deposits. The strategies applied were sulphation of KCl by sulphur/sulphate containing additives (i.e. elemental sulphur (S) and ammonium sulphate (AS)) and co-combustion with peat. Both sulphation of KCl and capture of potassium (K) in ash components can be of importance when peat is used. The experiments were mainly performed in a 12 MW circulation fluidised bed (CFB) boiler equipped for research purposes but also in a full-scale CFB boiler. The results were evaluated by means of IACM (on-line measurements of gaseous KCl), conventional gas analysis, deposit and corrosion probe measurements and ash analysis. Ammonium sulphate performed significantly better than elemental sulphur. Thus the presence of SO{sub 3} (i.e. AS) is of greater importance than that of SO{sub 2} (i.e. S) for sulphation of gaseous KCl and reduction of chlorine in deposits. Only a minor reduction of gaseous KCl was obtained during co-combustion with peat although chlorine in the deposits was greatly reduced. This reduction was supposedly due to capture of K by reactive components from the peat ash in parallel to sulphation of KCl. These compounds remained unidentified. The effect of volatile combustibles on the sulphation of gaseous KCl was investigated. The poorest sulphation was attained during injection of ammonium sulphate in the upper part of the combustion chamber during the lowest air excess ratio. The explanation for this is that SO{sub 3} was partly consumed by side reactions due to the presence of combustibles. These experimental results were supported by modelling, although the

1997 toxic chemical release inventory. Emergency Planning and Community Right-To-Know Act, Section 313

International Nuclear Information System (INIS)

Zaloudek, D.E.

1998-01-01

Two listed toxic chemicals were used at the Hanford Site above established activity thresholds: phosphoric acid and chlorine. Because total combined quantities of chlorine released, disposed, treated, recovered through recycle operations, co-combusted for energy recovery, and transferred to off-site locations for the purpose of recycle, energy recovery, treatment, and/or disposal, amounted to less than 500 pounds, the Hanford Site qualified for the alternate one million pound threshold for chlorine. Accordingly, this Toxic Chemical Release Inventory includes a Form A for chlorine, and a Form B for phosphoric acid

Consideration of the energetic use of waste wood versus re-use of materials

International Nuclear Information System (INIS)

Bergsma, G.C.; Sas, H.

1997-01-01

Recycling of wood wastes to chipboard is compared with the combustion of waste wood in combination with high-efficient energy recovery. Both options show much better environmental effects than the disposal of wood wastes. The differences between the environmental effects of the first two options can be neglected. The reprocessing of wood wastes to chipboard results in a decrease of the production of gypsum board. That benefit is equal to the benefit of cocombustion of wood wastes in a coal-fired power plant, i.e. saving coal. 18 refs

Coal-peat compositions for co-combustion in local boilers

Directory of Open Access Journals (Sweden)

А. В. Михайлов

2016-08-01

Full Text Available In article results of experiments on creation of coal and peat fuel compositions for burning in solid-fuel boilers are described. The main objective of research consisted in development of combination of coal dust and natural peat without binding additives. The role of peat consists that it increases efficiency of process of granulation, being natural binding. The method of granulation allows to utilize waste of the coal industry. Joint burning of two types of fuel – coal dust and peat reduces emission of sulfur dioxides. The cost of peat raw materials is lower, than artificial binding, applied to briquetting of coal dust. The composition of mix of coal dust and peat varied in the ratio 2:1, 1:1 and 1:2 in volume ratio at humidity of mix before extrusion of 65 %. In the course of preparatory operations of coal raw materials its crushing and sifting through sieve of 24 mesh (0,707 mm was carried out. Procedure of hashing of samples of coal and peat was carried out before receiving homogeneous mixture. After hashing mix was located in piston press for receiving granules. Coal dust and wet peat pass semifixed extrusion on piston press with formation of cylindrical granules with a diameter of 16 mm. After extrusion of granule are dried to operational humidity of 25 %. Coal and peat fuel granules showed sufficient mechanical strength for transportation and power feed in solid-fuel boilers. Burning of coal and peat fuel granules in vitro at temperature of 800 °C does not lead to ashes agglomeration. The conducted preliminary researches showed prospects of utilization of coal waste by granulation method in mix with natural peat.

Emissions from co-combustion of wood and household refuse

International Nuclear Information System (INIS)

Zhang, X.J.; Peterson, F.

1996-01-01

An investigation was carried out on the emissions produced in a 20 kW experimental boiler burning a combination of wood and household refuse. The wood content ranged form 10 to 50%. Direct sampling with Tenax adsorbent was used to cover a range of volatile organic compounds (VOCs). The measurements also included unburned hydrocarbons, carbon monoxide, carbon dioxide, oxygen and flue gas temperature. Combustion and emission parameters were recorded continuously with a multi-point data logger. VOCs were analyzed by gas chromatography and mass spectrometer (GC/MS). The main emphasis was placed on the effect of wood on VOC emissions. The results showed that as the wood content increased from 10 to 50%, there was a roughly linear increase in emissions of total VOCs. Carbon monoxide and unburned hydrocarbon emissions also increased. These results suggest that household refuse is a good substitute for wood as a boiler fuel, as it has a similar calorific value but fewer emissions. (Author)

Mercury speciation in pulverized fuel co-combustion and gasification

NARCIS (Netherlands)

Sable, S.P.

2007-01-01

Coal based power generation is a significant source of mercury emissions to the atmosphere and this has attracted huge attention in the past decade. Recently, the concerns regarding global warming and need for new energy resources introduced the concept of cofiring of biomass and waste as secondary

Contributions to the DGMK technical meeting `Energy and products from wastes and renewable resources`. Manuscripts; Beitraege zur DGMK-Fachbereichstagung ``Energetische und stoffliche Nutzung von Abfaellen und nachwachsenden Rohstoffen``. Autorenmanuskripte

Energy Technology Data Exchange (ETDEWEB)

NONE

1997-12-31

Described are several methods of energetic use of wastes (mainly plastic wastes) and biomass, as well as the recycling of plastic wastes. Processes described here are: NOELL conversion process, Thermoselect, PyroMelt process, Siemens carbonization combustion process, as well as several methods of gasification, pyrolysis, combustion, co-combustion. (SR) [Deutsch] In diesem Tagungsband werden verschiedene Moeglichkeiten der Energiegewinnung aus Abfaellen (hauptsaechlich Kunststoffen) und Biomasse, sowie das Recycling von Kunststoffabfaellen dargestellt. Es wir d auf folgende Verfahren eingegangen: NOELL-Konversionsverfahren, Thermoselect, PyroMelt-Verfahren, Siemens Schwel-Brenn-Verfahren, sowie verschiedene Methoden der Vergasung, Pyrolyse, Verbrennung, Mitverbrennung. (SR)

Contributions to the DGMK technical meeting `Energy and products from wastes and renewable resources`. Manuscripts; Beitraege zur DGMK-Fachbereichstagung ``Energetische und stoffliche Nutzung von Abfaellen und nachwachsenden Rohstoffen``. Autorenmanuskripte

Energy Technology Data Exchange (ETDEWEB)

NONE

1996-12-31

Described are several methods of energetic use of wastes (mainly plastic wastes) and biomass, as well as the recycling of plastic wastes. Processes described here are: NOELL conversion process, Thermoselect, PyroMelt process, Siemens carbonization combustion process, as well as several methods of gasification, pyrolysis, combustion, co-combustion. (SR) [Deutsch] In diesem Tagungsband werden verschiedene Moeglichkeiten der Energiegewinnung aus Abfaellen (hauptsaechlich Kunststoffen) und Biomasse, sowie das Recycling von Kunststoffabfaellen dargestellt. Es wir d auf folgende Verfahren eingegangen: NOELL-Konversionsverfahren, Thermoselect, PyroMelt-Verfahren, Siemens Schwel-Brenn-Verfahren, sowie verschiedene Methoden der Vergasung, Pyrolyse, Verbrennung, Mitverbrennung. (SR)

European energy crops overview. Country report for Denmark

Energy Technology Data Exchange (ETDEWEB)

Statens Planteavlsforsoeg, Tjele Denmark; Statens Jordbrugstekniske Forsoeg, Horsens Denmark

1996-06-01

Biomass constitutes a significant contribution to the Danish energy production and is a major tool in increasing the contribution from renewables. So far the focus has been on utilizing existing biomass residues like straw and forest residues and not energy crops. The government has agreed to carry out a demonstration and development programme on energy crops in order to analyse aspects of economy, energy, environment, nature conservancy and comerciality. Several plant species have been investigated for their potential as energy crops and overview information in presented on buchina, sunflower, knotweed, Jerusalem artichoke, false flax, reed Canary grass and corn cockle. More detailed descriptions are given on willow, Miscanthus, energy grain (grain whole crop) and rape which have been most intensively investigated. Rape has been the energy crop grown on the largest scale (40-50,000 ha) but the oil has not been used for energy purposes in Denmark. A research programme on the development of a low input production system for non-food rape is currently conducted. The perennial crops willow and Miscanthus are grown with low input of fertilizer and pesticides and are considered environmentally friendly. Willow-SRC is used as fuel at district heating plants, both commercially and for feasibility studies. Full-scale tests have been carried out on Miscanthus combustion in farm heating plant constructed for straw firing, and on co-combustion with coal at power stations. Grain whole crop (energy grain) has been combusted at a district heating plant, a CHP-plant and a power station. Co-combustion with coal was carried out at a CFB-boiler. Concerning ethanol based on energy crops, only a few activities are in progress. (EG) 89 refs.

Life cycle assessment of fossil and biomass power generation chains. An analysis carried out for ALSTOM Power Services

Energy Technology Data Exchange (ETDEWEB)

Bauer, Ch.

2008-12-15

This final report issued by the Technology Assessment Department of the Paul Scherrer Institute (PSI) reports on the results of an analysis carried out on behalf of the Alstom Power Services company. Fossil and biomass chains as well as co-combustion power plants are assessed. The general objective of this analysis is an evaluation of specific as well as overall environmental burdens resulting from these different options for electricity production. The results obtained for fuel chains including hard coal, lignite, wood, natural gas and synthetic natural gas are discussed. An overall comparison is made and the conclusions drawn from the results of the analysis are presented.

Decree of the 23 May 2016 related to installations of heat and/or electric power production from non-hazardous wastes prepared under the form of recovery solid fuels in installations designed for this purpose and associated or not with another fuel covered by section 2971 of the nomenclature of installations classified for the protection of the environment. Decree of the 23 May 2016 related to the preparation of recovery solid fuels in view of their use in installations covered by section 2971 of the nomenclature of installations classified for the protection of the environment

International Nuclear Information System (INIS)

Mortureux, M.

2016-01-01

A first decree presents the various prescriptions regulating installations used for the co-combustion of recovery solid fuels for the production of heat and/or electricity: definition and scope of application, design and general arrangement of installations, conditions for fuel admission and delivery, conditions of exploitation, risk prevention, air pollution prevention, water pollution prevention, management and processing of residues, release monitoring and impact on the environment, information on installation operation or stoppage. Appendices provide limit values for atmospheric releases, equivalence factors for dibenzo-para-dioxines and dibenzofuranes, limit values for liquid effluents. The second decree addresses the regulation of the preparation and production of recovery solid fuels

Tracing anthropogenic thallium in soil using stable isotope compositions.

Science.gov (United States)

Kersten, Michael; Xiao, Tangfu; Kreissig, Katharina; Brett, Alex; Coles, Barry J; Rehkämper, Mark

2014-08-19

Thallium stable isotope data are used in this study, for the first time, to apportion Tl contamination in soils. In the late 1970s, a cement plant near Lengerich, Germany, emitted cement kiln dust (CKD) with high Tl contents, due to cocombustion of Tl-enriched pyrite roasting waste. Locally contaminated soil profiles were obtained down to 1 m depth and the samples are in accord with a binary mixing relationship in a diagram of Tl isotope compositions (expressed as ε(205)Tl, the deviation of the (205)Tl/(203)Tl ratio of a sample from the NIST SRM 997 Tl isotope standard in parts per 10(4)) versus 1/[Tl]. The inferred mixing endmembers are the geogenic background, as defined by isotopically light soils at depth (ε(205)Tl ≈ -4), and the Tl emissions, which produce Tl-enriched topsoils with ε(205)Tl as high as ±0. The latter interpretation is supported by analyses of the CKD, which is also characterized by ε(205)Tl ≈ ± 0, and the same ε(205)Tl value was found for a pyrite from the deposit that produced the cocombusted pyrite roasting waste. Additional measurements for samples from a locality in China, with outcrops of Tl sulfide mineralization and associated high natural Tl backgrounds, reveal significant isotope fractionation between soils (ε(205)Tl ≈ +0.4) and locally grown green cabbage (ε(205)Tl between -2.5 and -5.4). This demonstrates that biological isotope fractionation cannot explain the isotopically heavy Tl in the Lengerich topsoils and the latter are therefore clearly due to anthropogenic Tl emissions from cement processing. Our results thus establish that isotopic data can reinforce receptor modeling for the toxic trace metal Tl.

Thermodynamic aspects of heavy metal volatility during utilisation of the energetic and material fraction of waste materials; Schwermetallfluechtigkeit bei der energetischen und stofflichen Verwertung von Abfaellen aus der Sicht der Thermodynamik

Energy Technology Data Exchange (ETDEWEB)

Meyer, B; Starke, A [TU Bergakademie Freiberg (Germany). Inst. IEC

1998-09-01

Co-combustion plants, in which fuel is partly substituted by waste materials, are subject to the 17th BImSchV (Nuisance Control Ordinance) provided that the thermal fraction of 25% is not exceeded. Emission limits are calculated proportionately on the basis of limiting values for emissions from coal power stations (13th BImSchV) and waste incinerators (17th BImSchV). Compared to coal, waste has higher concentrations of heavy metals and halogens, which results in enhanced emissions of heavy metal compounds and chlorides with the flue gas and gasification gas. Plant operators intending to opt for co-combustion must check if the existing flue gas purification system is efficient enough to meet the specifications of the 17th BImSchV. In general, thermodynamic modelling is the most common method of evaluation and optimisation for high-temperature processes of this kind. (orig./SR) [Deutsch] Da bei der Mitverbrennung ein Teil des Brennstoffes durch den Reststoff substituiert wird, unterliegen diese Anlagen der Anteilsregelung nach 17. BImSchV, sofern ein thermischer Anteil von 25% nicht ueberschritten wird. Emissionsgrenzwerte werden anteilig aus den z.B. fuer Kohlekraftwerke gueltigen Grenzwerten nach TA Luft oder 13. BImSchV und denen fuer Abfaelle u.ae. nach 17 BImSchV ermittelt. Der hier betrachtete Reststoff Muell beinhaltet im Vergleich zur Kohle hohe Konzentrationen an Schwermetallen und Halogenen. Dies laesst eine erhoehte Emission von Schwermetallverbindungen und Chloriden mit dem Rauchgas bzw. Vergasungsgas erwarten. Es muss in jedem Fall ueberprueft werden, ob die vorhandene Rauchgasreinigung ausreicht, wenn bei der Mitverbrennung/-vergasung die Emissionsgrenzwerte der 17. BImSchV zur Anwendung kommen. Als Bewertungs- und Optimierungsmethode fuer derartige Hochtemperaturprozesse setzt sich die thermodynamische Modellierung zunehmend durch. (orig./SR)

Measures for simultaneous minimization of alkali related operating problems, Phase 2; Aatgaerder foer samtidig minimering av alkalirelaterade driftproblem, Etapp 2. Ramprogram

Energy Technology Data Exchange (ETDEWEB)

Gyllenhammar, Marianne; Herstad Svaerd, Solvie; Davidsson, Kent; Aamand, Lars-Erik; Steenari, Britt-Marie; Folkeson, Nicklas; Pettersson, Jesper; Svensson, Jan-Erik; Boss, Anna; Johansson, Linda; Kassman, Haakan

2007-12-15

Combustion of an increasing amount of biofuel and waste woods has resulted in certain environmental advantages, including decreased emissions of fossil CO{sub 2}, SO{sub 2} and metals. On the other hand, a number of chloride and alkali related operational problems have occurred which are related to combustion of these fuels. Alkali related operational problems have been studied in a project consisting of two parts. The overall scope has been to characterise the operational problems and to study measures to minimise them. The first part was reported in Vaermeforsk report 997. In part two, additional measures have been included in the test plan and initial corrosion has been studied linked to the different measures. The tests have also in part two been carried out at the 12 MW CFB boiler at Chalmers. The effect of the selected measures has been investigated concerning both deposit formation and bed agglomeration, and at the same time emissions and other operational conditions were characterised. The second part of the project has among other things focused on: To investigate measures which decrease the content of alkali and chloride in the deposits, and consequently decrease the risk for corrosion (by investigating the initial corrosion). Focus was also on trying to explain favourable effects. To investigate if it is possible to combine a rather low dosage of kaolin and injection of ammonium sulphate. This was done in order to reduce both bed agglomeration and problems from deposits during combustion of fuels rich in chlorine. To investigate if co-combustion with sewage sludge, de-inking sludge or peat with high ash content, could give similar advantages as conventional additives. Investigate if ash from PFBC (coal ash and dolomite) is possible to use as an alternative bed material. In the reference case, straw pellets were co-combusted together with wood pellets. This fuel mixture gave high alkali and chlorine contents. Alkali was in surplus of chlorine. The

Thermal treatment of sewage sludge from waste water. Tratamiento termico de lodos procedentes de aguas residuales

Energy Technology Data Exchange (ETDEWEB)

Andreottola, G. (Universidad de Trento (Italy)); Canziani, R.; Ragazzi, M. (Politicnico de Milan (Italy))

1994-01-01

Thermal Treatment of sewage sludge can be beneficial as a pre-treatment step of many treatment/disposal options, but above all, it allows the recovery of the energetic content sludge. Energy recovery from sewage sludge can be performed in many ways; direct incineration thermal drying followed by incineration and co-combustion with municipal solid wastes or other non conventional fuels. Another option is the recovery of waste energy (e.g. from an endo thermal engine using biogas as fuel) to dry sludge wich, in turn can be used as a fuel. The paper will evaluate several options of thermal treatment of sewage sludge, with particular emphasis on the energetic yield from different processes. (Author)

Energy recovery of combustible fraction from fragmentation of metal scrap - Phase 2; Energiaatervinning av braennbar fraktion fraan fragmentering av metallhaltigt avfall - Steg 2

Energy Technology Data Exchange (ETDEWEB)

Gyllenhammar, Marianne (Stena Metall AB (Sweden)); Davidsson, Kent (SP Sveriges Tekniska Forskningsinstitut, Boraas (Sweden)); Jonsson, Torbjoern; Pettersson, Jesper (HTC, Chalmers Tekniska Hoegskola, Goeteborg (Sweden)); Victoren, Anders; Andersson, Hans (Metso Power AB (Sweden)); Widen, Christoffer (Lidkoepings Vaermeverk AB (Sweden))

2010-03-15

More recovered fuels have been put on the fuel market since the landfill ban of organic wastes was implemented. SLF (shredder light fraction = fluff) which is a waste from recovery of metal scrap has mostly been put on landfill until now. Due to high chlorine and metal content in this fuel there is a risk of increased deposit and corrosion problems in incineration plants. This project investigated if co-combustion with sewage sludge could reduce these problems. The purpose of the project was also to document the influence of SLF when it comes to deposits and corrosion in an incineration plant. In this project SLF has been co-combusted with normal waste with and without sewage sludge in the 20 MW bubbling fluidized bed boiler in Lidkoeping. Three combustion tests have been performed: - Ref - Reference test (normal fuel mix = 50% household waste/50% industrial waste). - F1 - Test 1 (75% normal fuel mix , 21% SLF and 4% sewage sludge) - F2 - Test 2 (77% normal fuel mix and 23% SLF) The fuel mix is specified as percentage of energy content. The tests lasted 3 days and during the last 24 hours corrosion and deposit probes were exposed inside the boiler. The surface temperatures of the corrosion probes were 280, 350 and 420 deg C in each test. At the same time as the probes were exposed the boiler operation was followed and samples of fuel, ash and flue gas were taken. The results clearly show that sewage sludge initially decreases the deposit and corrosion problems at SLF combustion. Lower amounts of deposits were measured and the deposits were less corrosive when 4% of sewage sludge was added to the fuel mix with normal waste and SLF (F1). Co-combustion of more than 20% SLF and wastes (F2) increase initially the amount of the deposits and the deposits were also initially more corrosive. Long-term consequences are not investigated in this project. The project has not shown a distinct explanation why sewage sludge gives these good effects. Several possible causes, as

Release of nitrogen precursors from coal and biomass residues in a bubbling fluidized bed

Energy Technology Data Exchange (ETDEWEB)

P. Abelha; I. Gulyurtlu; I. Cabrita [Instituto Nacional de Engenharia, Lisbon (Portugal)

2008-01-15

This work was undertaken with the aim of quantifying the relative amounts of NH{sub 3} and HCN released from different residues during their devolatilization under fluidized bed conditions. The results were compared with data collected for bituminous coals of different origin. The relation between amounts of HCN and NH{sub 3} released and the levels of NOX and N{sub 2}O formed during cocombustion was also addressed. The partitioning of nitrogen between volatiles and char was also quantified. The pyrolysis studies were undertaken in a small fluidized bed reactor of 80 mm of ID and 500 mm high using an inert atmosphere (N{sub 2}). The HCN and NH{sub 3} were quantified by bubbling the pyrolysis gases in absorbing solutions which were subsequently analyzed with selective electrodes. The combustion studies were carried out on a pilot installation. The fluidized bed combustor is square in cross section with each side being 300 mm long. There is secondary air supply to the freeboard at different heights to deal with high volatile fuels as almost all waste materials are. The temperatures in the bed and in the freeboard and that of the flue gases leaving the reactor were continuously monitored. The results obtained suggest that, while coal releases nitrogen mostly as HCN, residues like RDF and sewage sludge give out fuel-N in greater quantities as NH{sub 3}. Residues at fluidized bed combustion (FBC) temperatures release more than 80% of the fuel-N with the volatiles. The NH{sub 3} evolved during pyrolysis acted as a reducing agent on NOX emissions. The presence of calcium significantly reduces the emission of N{sub 2}O probably by interfering with HCN chemistry. With high amounts of residues in the fuel mixture, the relative importance of char on the nitrogen chemistry substantially decreases. By using cocombustion, it is possible to reduce fuel-N conversion to NOX and N{sub 2}O, by tuning the amounts of coal and residue in the mixture. 29 refs., 18 figs., 3 tabs.

Energy implications of mechanical and mechanical-biological treatment compared to direct waste-to-energy.

Science.gov (United States)

Cimpan, Ciprian; Wenzel, Henrik

2013-07-01

Primary energy savings potential is used to compare five residual municipal solid waste treatment systems, including configurations with mechanical (MT) and mechanical-biological (MBT) pre-treatment, which produce waste-derived fuels (RDF and SRF), biogas and/or recover additional materials for recycling, alongside a system based on conventional mass burn waste-to-energy and ash treatment. To examine the magnitude of potential savings we consider two energy efficiency levels (state-of-the-art and best available technology), the inclusion/exclusion of heat recovery (CHP vs. PP) and three different background end-use energy production systems (coal condensing electricity and natural gas heat, Nordic electricity mix and natural gas heat, and coal CHP energy quality allocation). The systems achieved net primary energy savings in a range between 34 and 140 MJprimary/100 MJinput waste, in the different scenario settings. The energy footprint of transportation needs, pre-treatment and reprocessing of recyclable materials was 3-9.5%, 1-18% and 1-8% respectively, relative to total energy savings. Mass combustion WtE achieved the highest savings in scenarios with CHP production, nonetheless, MBT-based systems had similarly high performance if SRF streams were co-combusted with coal. When RDF and SRF was only used in dedicated WtE plants, MBT-based systems totalled lower savings due to inherent system losses and additional energy costs. In scenarios without heat recovery, the biodrying MBS-based system achieved the highest savings, on the condition of SRF co-combustion. As a sensitivity scenario, alternative utilisation of SRF in cement kilns was modelled. It supported similar or higher net savings for all pre-treatment systems compared to mass combustion WtE, except when WtE CHP was possible in the first two background energy scenarios. Recovery of plastics for recycling before energy recovery increased net energy savings in most scenario variations, over those of full

Electrodialytic remediation of fly ash from co-combustion of wood and straw

International Nuclear Information System (INIS)

Chen, Wan; Jensen, Pernille E.; Ottosen, Lisbeth M.; Kirkelund, Gunvor M.

2015-01-01

The heavy metal content in fly ash from biomass combustion, such as straw, wood and sludge, often needs reducing before the ash can be used as fertilizer for agricultural land or as a component in the production of construction materials. In this study, fly ash from a boiler fueled with wood chips and straw was treated either by electrodialytic remediation (EDR) directly or by a combination of EDR and pre-wash with distilled water to investigate the possibilities of reducing the heavy metal content and reusing nutrients as fertilizer and bulk material in construction materials. Different experimental set-ups were tested for EDR treatment primarily of Cd and Pb as well as of Cu and Zn. Elemental contents such as K, P and Ni were compared in ash samples before and after treatment. The results showed that pre-washing caused an increase in total concentrations of most heavy metals because the highly soluble fraction, mainly KCl and K 2 SO 4 , was removed. After EDR treatment, the Cd concentration was reduced to below 2 mg kg −1 in all ash samples with high and stable average removal of above 95%, no matter how high the initial concentration was. The amount of Pb removed varied from 12% to 67%. Even though Pb was extracted from the ash samples, its concentrations in the treated ash samples were elevated due to the ash dissolution, except in the case of pre-washed ash treated in a two-compartment EDR cell, where the mass of Pb removed was the highest with a final concentration of about 100 mg kg −1 . The two-compartment EDR cell probably performed better due to a fast acidification process. In addition, this process was less energy-consuming. However, the fast acidification did in turn affect the leaching property of the treated ash, such as As and Ni, exceeding the limiting concentrations. The EDR/pre-wash-EDR treated ash mainly contained quartz, and the X-ray diffraction (XRD) peaks of K salts had disappeared. This shows that the potassium fertilizer potential was lost in the treated ashes, but the quartz mineral is beneficial in construction materials, such as ceramics. The K fertilizer could be recovered from the water after pre-washing and also from the catholyte through chemical operations, including a separation step.

Electrodialytic remediation of fly ash from co-combustion of wood and straw

DEFF Research Database (Denmark)

Chen, Wan; Jensen, Pernille Erland; Ottosen, Lisbeth M.

2015-01-01

The heavy metal content in fly ash from biomass combustion, such as straw, wood and sludge, often needs reducing before the ash can be used as fertilizer for agricultural land or as a component in the production of construction materials. In this study, fly ash from a boiler fueled with wood chips...... and straw was treated either by electrodialytic remediation (EDR) directly or by a combination of EDR and pre-wash with distilled water to investigate the possibilities of reducing the heavy metal content and reusing nutrients as fertilizer and bulk material in construction materials. Different experimental....../pre-wash-EDR treated ash mainly contained quartz, and the X-ray diffraction (XRD) peaks of K salts had disappeared. This shows that the potassium fertilizer potential was lost in the treated ashes, but the quartz mineral is beneficial in construction materials, such as ceramics. The K fertilizer could be recovered...

Deposit Formation during Coal-Straw Co-Combustion in a Utility PF-Boiler

DEFF Research Database (Denmark)

Andersen, Karin Hedebo

1998-01-01

the combustion conditions, including the method of introduction of the straw to the boiler, as well as the amount of Fe introduced as Pyrite with the coal.No significant effect could be found in the deposition probe samples for an increase in probe metal temperature from 540°C to 620°C. The importance of deposit...... area. The evaluation was performed for an opposed-wall fired and tangentially fired boiler, which are compared to the wall-fired MKS1. Two major aspects were evaluated: The effect of flue gas temperatures and the effect of mixing. However, no final recommandation for choise of boilertype can be given...

Melting Behavior of ashes from the co-combustion of coal and straw

DEFF Research Database (Denmark)

Arvelakis, Stelios; Frandsen, Flemming

2007-01-01

. The use of straw as a co-firing feedstock in traditional coal-fired plants is associated with operational problems, such as deposition, agglomeration, and/or corrosion, mainly because of the higher amounts of alkali metals and chlorine in straw compared to coal. This may lead to unscheduled shutdowns...

Characteristics and synergistic effects of co-combustion of carbonaceous wastes with coal.

Science.gov (United States)

Onenc, Sermin; Retschitzegger, Stefan; Evic, Nikola; Kienzl, Norbert; Yanik, Jale

2018-01-01

This study presents combustion behavior and emission results obtained for different fuels: poultry litter (PL) and its char (PLC), scrap tires (ST) and its char (STC) and blends of char/lignite (PLC/LIG and STC/LIG). The combustion parameters and emissions were investigated via a non-isothermal thermogravimetric method and experiments in a lab-scale reactor. Fuel indexes were used for the prediction of high temperature corrosion risks and slagging potentials of the fuels used. The addition of chars to lignite caused a lowering of the combustion reactivity (anti-synergistic effect). There was a linear correlation between the NO x emissions and the N content of the fuel. The form of S and the concentrations of alkali metals in the fuel had a strong effect on the extent of SO 2 emissions. The use of PL and PLC in blends reduced SO 2 emissions and sulphur compounds in the fly ash. The 2S/Cl ratio in the fuel showed that only PLC and STC/PLC would show a risk of corrosion during combustion. The ratio of basic to acidic oxides in fuel indicated that ST, STC and STC/LIG have low slagging potential. The molar (Si+P+K)/(Ca+Mg) ratio, which was used for PL, PLC and PLC containing blends, showed that the ash melting temperatures of these fuels would be higher than 1000 °C. Copyright © 2017 Elsevier Ltd. All rights reserved.

Hydrocarbon conversion with cracking catalyst having co-combustion promoters lanthanum and iron

International Nuclear Information System (INIS)

Csicsery, S.M.

1979-01-01

A composition useful in hydrocarbon conversion processes such as catalytic cracking comprises 0.05 to 10 weight percent lanthanum associated with a refractory support. The composition may also include 0.02 to 10 weight percent iron. The refractory support is a zeolitic crystalline aluminosilicate

Water pollution control technology in Japan

Energy Technology Data Exchange (ETDEWEB)

NONE

1997-11-01

This work is a compilation by members of the Committee for Studying Transfer of Environmental Technology on the expertise and technology developed by the members for controlling water pollution in Japan, together with consideration of issues concerning the transfer of environmental technologies to developing countries. The committee is composed of representatives for the Environment Agency, Japan, Osaka Prefectural Government, Osaka Municipal Government, and 25 companies such as manufacturers of environmental equipment. The document contains a total of 93 short papers grouped into sections on: industrial wastewater treatment; sewage treatment; right soil treatment; sludge treatment; and miscellaneous. One paper by the Kausai Electric Power Co., Inc., discusses waste water treatment systems in oil-fired thermal power plants; another describes an internally circulating fluidized bed boiler for cocombusting coal with industrial wastes.

Long-term affected energy production of waste to energy technologies identified by use of energy system analysis

DEFF Research Database (Denmark)

Münster, Marie; Meibom, Peter

2010-01-01

Affected energy production is often decisive for the outcome of consequential life-cycle assessments when comparing the potential environmental impact of products or services. Affected energy production is however difficult to determine. In this article the future long-term affected energy...... production is identified by use of energy system analysis. The focus is on different uses of waste for energy production. The Waste-to-Energy technologies analysed include co-combustion of coal and waste, anaerobic digestion and thermal gasification. The analysis is based on optimization of both investments...... and production of electricity, district heating and bio-fuel in a future possible energy system in 2025 in the countries of the Northern European electricity market (Denmark, Norway, Sweden, Finland and Germany). Scenarios with different CO2 quota costs are analysed. It is demonstrated that the waste...

The ChlorOut concept. A method to reduce alkali-related problems during combustion

Energy Technology Data Exchange (ETDEWEB)

Kassman, Haakan [ChlorOut AB c/o Vattenfall AB, Nykoeping (Sweden); Wollner, Lothar [Boehringer Ingelheim Pharma GmbH und Co. KG, Ingelheim am Rhein (Germany); Berg, Magnus [ChlorOut AB c/o Vattenfall AB, Stockholm (Sweden)

2013-06-01

Combustion of biomass with a high content of alkali and chlorine (Cl) can result in operational problems including deposit formation and superheater corrosion. The strategies applied to reduce such problems include co-combustion and the use of additives. Ammonium sulphate is a part of the ChlorOut concept which is applied in a range of commercial boilers. This concept is based on dosing of sulphate-containing additives to the flue gases and a unique measurement device for on-line measurement of gaseous alkali chlorides called IACM (in-situ alkali chloride monitor). The focus of the present paper is on evaluation of long-term experiences from two full-scale boilers. The operational problems with deposit formation and superheater corrosion decreased in these boilers after installing the ChlorOut concept. (orig.)

Optimal utilization of waste-to-energy in an LCA perspective

DEFF Research Database (Denmark)

Fruergaard, Thilde; Astrup, Thomas

2011-01-01

Energy production from two types of municipal solid waste was evaluated using life cycle assessment (LCA): (1) mixed high calorific waste suitable for production of solid recovered fuels (SRF) and (2) source separated organic waste. For SRF, co-combustion was compared with mass burn incineration....... For organic waste, anaerobic digestion (AD) was compared with mass burn incineration. In the case of mass burn incineration, incineration with and without energy recovery was modelled. Biogas produced from anaerobic digestion was evaluated for use both as transportation fuel and for heat and power production....... All relevant consequences for energy and resource consumptions, emissions to air, water and soil, upstream processes and downstream processes were included in the LCA. Energy substitutions were considered with respect to two different energy systems: a present-day Danish system based on fossil fuels...

AFB-NETT - business opportunities for European biomass industry

International Nuclear Information System (INIS)

Higham, I.

1997-01-01

The AFB-NETT is an ALTENER funded project lead by ETSU. The project was started in 1995 with 11 partner nations. The initial aim was to bring together the whole biomass supply and use chain, not just within countries but across the Europe. At present more than 280 people take part in the network. The four objectives of the project are: detection and promotion of business opportunities; transfer of knowledge and experience; promotion of collaboration and co-ordination; and implementation of National and European Strategies. The effort in 1997 split into four main activities, 2 of which based on market sectors and two on improving the market conditions. The activities for 1997 were (the leader in parentheses): Co-combustion and gasification (Finland); Small scale and district heat (Austria); Financial incentives (the Netherlands); Wood fuel and emission standards (UK)

AFB-NETT - business opportunities for European biomass industry

Energy Technology Data Exchange (ETDEWEB)

Higham, I [ETSU, Oxfordshire (United Kingdom)

1998-12-31

The AFB-NETT is an ALTENER funded project lead by ETSU. The project was started in 1995 with 11 partner nations. The initial aim was to bring together the whole biomass supply and use chain, not just within countries but across the Europe. At present more than 280 people take part in the network. The four objectives of the project are: detection and promotion of business opportunities; transfer of knowledge and experience; promotion of collaboration and co-ordination; and implementation of National and European Strategies. The effort in 1997 split into four main activities, 2 of which based on market sectors and two on improving the market conditions. The activities for 1997 were (the leader in parentheses): Co-combustion and gasification (Finland); Small scale and district heat (Austria); Financial incentives (the Netherlands); Wood fuel and emission standards (UK)

AFB-NETT - business opportunities for European biomass industry

Energy Technology Data Exchange (ETDEWEB)

Higham, I. [ETSU, Oxfordshire (United Kingdom)

1997-12-31

The AFB-NETT is an ALTENER funded project lead by ETSU. The project was started in 1995 with 11 partner nations. The initial aim was to bring together the whole biomass supply and use chain, not just within countries but across the Europe. At present more than 280 people take part in the network. The four objectives of the project are: detection and promotion of business opportunities; transfer of knowledge and experience; promotion of collaboration and co-ordination; and implementation of National and European Strategies. The effort in 1997 split into four main activities, 2 of which based on market sectors and two on improving the market conditions. The activities for 1997 were (the leader in parentheses): Co-combustion and gasification (Finland); Small scale and district heat (Austria); Financial incentives (the Netherlands); Wood fuel and emission standards (UK)

Measures for simultaneous minimisation of alkali related operating problems; Aatgaerder foer samtidig minimering av alkalirelaterade driftproblem. Ramprogram

Energy Technology Data Exchange (ETDEWEB)

Davidsson, Kent; Eskilsson, David; Gyllenhammar, Marianne; Herstad Svaerd, Solvie; Kassman, Haakan; Steenari, Britt-Marie; Aamand, Lars-Erik

2006-12-15

Combustion of biofuel and waste wood is often accompanied by chlorine and alkali related operating problems such as slagging, deposit formation and corrosion on heat exchanger surfaces and bed agglomeration in fluidised bed boilers. In order to gain a greater insight into possible measures to overcome alkali related operating problems studies were carried out during 2005-2006. The results of the studies are presented in this report which includes work performed in the two following projects: 1 A5-509 Frame work - measures for simultaneous minimisation of alkali related operating problems 2 A5-505 Bed agglomeration risk related to combustion of cultivated fuels (wheat straw, red canary grass, industrial hemp) in commercial bed materials Full-scale experiments were carried out at Chalmers 12 MW{sub th} CFB boiler within the project A5-509. The purpose was to study the effect of various measures on bed agglomeration and deposit formation in connection with co-combustion of wood and straw pellets. The various measures included changing the bed material (blast furnace sand and olivine sand), adding various additives (kaolin, ammonium sulphate, elemental sulphur) and also co-combustion with sewage sludge. Furthermore results from kaolin experiments at the 26 MWth CFB boiler owned by Naessjoe Affaersverk were made available during the project and are also presented in this report. The results from the experiments at Chalmers revealed that, already at the lowest dosage of kaolin, approx. 2 kg/MWh, the bed material agglomeration temperatures increased significantly. The dosage of kaolin can presumably be reduced somewhat further while still maintaining the high agglomeration temperature. Experiments with a higher dosage of kaolin, 7 kg/MWh, proved that kaolin could also reduce the risk of deposit problems. The experiments at Naessjoe showed also that addition of kaolin increased the agglomeration temperature of the bed material. Addition of sulphur in any form resulted in a

CO-COMBUSTION OF REFUSE DERIVED FUEL WITH COAL IN A FLUIDISED BED COMBUSTOR

Directory of Open Access Journals (Sweden)

W. A. WAN AB KARIM GHANI

2009-03-01

Full Text Available Power generation from biomass is an attractive technology which utilizes municipal solid waste-based refused derived fuel. In order to explain the behavior of biomass-fired fluidized bed incinerator, biomass sources from refuse derived fuel was co-fired with coal in a 0.15 m diameter and 2.3 m high fluidized bed combustor. The combustion efficiency and carbon monoxide emissions were studied and compared with those from pure coal combustion. This study proved that the blending effect had increased the carbon combustion efficiency up to 12% as compared to single MSW-based RDF. Carbon monoxide levels fluctuated between 200-1600 ppm were observed when coal is added. It is evident from this research that efficient co-firing of biomass with coal can be achieved with minimum modification of existing coal-fired boilers.

Co-Combustion of waste and biomass ''the Dutch approach''

Energy Technology Data Exchange (ETDEWEB)

Dijkman, B.

2002-07-01

This introduction starts an overview of the greenhouse gas policy in the Netherlands, focussing to reduction programs in the electricity industry and how the industry anticipates. An impression will be given about the needed adaption programs of coal-fired power plants, and how projects are financed. But before starting with the major part of this paper, the actual situation in the Dutch electricity industry will be explained, because liberalisation and privatisation have carved new tracks. The organisation and ownership of the Dutch electricity scene has been changed dramatically in the past 5 years. (orig.)

Co-combustion of gasified contaminated waste wood in a coal fired power plant

Energy Technology Data Exchange (ETDEWEB)

NONE

2001-07-01

This project demonstrates the technical and economical feasibility of the producing and cofiring of product gas from demolition waste wood. For this purpose LCV product gas is generated in an atmospheric circulating fluidized bed (CFB) gasification plant, cooled and cleaned and transported to the boiler of a 600 MWe pulverized coal fired power plant. Gas cooling and cleaning takes place in a waste heat boiler and a multi stage wet gas cleaning train. Steam raised in the waste heat boiler is exported to the power plant. On an annual basis 70,000 tons of steam coal are substituted by 150,000 tons of contaminated demolition waste wood (50,000 tons oil equivalent), resulting in a net CO2 emission reduction of 170,000 tons per year, while concurrently generating 205 GWh of electrical power. The wood gasification plant was built by NV EPZ (now incorporated in Essent Energi BV) for Amergas BV, now a 100% subsidiary of Essent Energie BV. The gasification plant is located at the Amer Power Station of NV EPZ Production (now Essent Generation) at Geertruidenberg, The Netherlands. Demonstrating several important design features in wood gasification, the plant started hot service in the Spring of 2000, with first gasification accomplished in the Summer of 2000 and is currently being optimized. (au)

The recovery of waste and off-gas in Large Combustion Plants subject to IPPC National Permit in Italy.

Science.gov (United States)

Di Marco, Giuseppe; Manuzzi, Raffaella

2018-03-01

The recovery of off-gas, waste, and biomass in Large Combustion Plants for energy production gives the opportunity to recycle waste and by-products and to recover materials produced in agricultural and industrial activities. The paper illustrates the Italian situation regarding the production of energy from off-gas, biomass, and waste in Large Combustion Plants subject to Integrated Pollution Prevention and Control (IPPC) National Permit. Moreover, it focuses on the 4 Italian Large Combustion Plants producing energy from biomass and waste. For these ones it illustrates the specific issues related to and provides a description of the solutions adopted in the 4 Italian plants. Given that air emission performance is the most relevant aspect of this kind of plants, the paper specifically focuses and reports results about this subject. In particular, in Italy among 113 LCPs subject to IPPC National Permit we have found that 4 plants use as fuel waste (i.e. solid or liquid biomasses and Solid Recovered Fuels), or a mixture of waste and traditional fuels (co-combustion of Solid Recovered Fuels and coal), and that 11 plants use as fuel off-gases listed in Annex X (i.e. Refinery Fuel Gas, Syngas, and gases produced in iron and steel industries). Moreover, there are 2 IPPC chemical plants that recovery energy from different off-gases not listed in Annex X. Regarding the 4 LCPs that produce energy from waste combustion or co-combustion, we find that they take into account all the specific issues related to this kind of plants (i.e. detailed waste characterization, waste acceptance procedures, waste handling and storage, waste pretreatment and emissions to air), and adopt solutions that are best available techniques to prevent pollution. Moreover for one of these plants, the only one for which we have a significant set of monitoring data because it obtained the IPPC National Permit in 2008, we find that energy efficiency and air emissions of the principal pollutants are in

Disposal of sewage sludge. Rotary kiln plants and energetic utilization of sewage sludge; Klaerschlammentsorgung. Drehrohranlagen in der Trocknung und energetischen Nutzung von Klaerschlamm

Energy Technology Data Exchange (ETDEWEB)

Hormes, Franz [Visser und Smit Hanab GmbH, Kaarst (Germany). Rotary Kilns

2013-03-01

The author of the contribution under consideration reports on rotary kiln plants in the disposal of sewage sludge. The examples give an insight into the systems engineering for the thermal treatment of sewage sludge, for the minimization or full thermal utilization. The examples show that there exists any specific solution. The process selection depends on the legal requirements and the framework conditions in dependence from the site and infrastructure. Generally, the following statements are valid: (a) The co-combustion is cheaper than every mono-combustion; (b) The costs for the transport of wet sludge often are more favourable than the costs of drying; (c) Plants for low capacities are specifically expensive. The following criteria become more important: (a) energy costs, recycling of energy; (b) recycling of phosphorus from sewage sludge; (c) Reduction of the input of heavy metals in order to comply with the fertilizer ordinance.

Co-firing straw and coal in a 150-MWe utility boiler: in situ measurements

DEFF Research Database (Denmark)

Hansen, P. F.B.; Andersen, Karin Hedebo; Wieck-Hansen, K.

1998-01-01

A 2-year demonstration program is carried out by the Danish utility I/S Midtkraft at a 150-MWe PF-boiler unit reconstructed for co-firing straw and coal. As a part of the demonstration program, a comprehensive in situ measurement campaign was conducted during the spring of 1996 in collaboration...... with the Technical University of Denmark. Six sample positions have been established between the upper part of the furnace and the economizer. The campaign included in situ sampling of deposits on water/air-cooled probes, sampling of fly ash, flue gas and gas phase alkali metal compounds, and aerosols as well...... deposition propensities and high temperature corrosion during co-combustion of straw and coal in PF-boilers. Danish full scale results from co-firing straw and coal, the test facility and test program, and the potential theoretical support from the Technical University of Denmark are presented in this paper...

SVM-based multisensor data fusion for phase concentration measurement in biomass-coal co-combustion

Science.gov (United States)

Wang, Xiaoxin; Hu, Hongli; Jia, Huiqin; Tang, Kaihao

2018-05-01

In this paper, the electrical method combines the electrostatic sensor and capacitance sensor to measure the phase concentration of pulverized coal/biomass/air three-phase flow through data fusion technology. In order to eliminate the effects of flow regimes and improve the accuracy of the phase concentration measurement, the mel frequency cepstrum coefficient features extracted from electrostatic signals are used to train the Continuous Gaussian Mixture Hidden Markov Model (CGHMM) for flow regime identification. Support Vector Machine (SVM) is introduced to establish the concentration information fusion model under identified flow regimes. The CGHMM models and SVM models are transplanted on digital signal processing (DSP) to realize on-line accurate measurement. The DSP flow regime identification time is 1.4 ms, and the concentration predict time is 164 μs, which can fully meet the real-time requirement. The average absolute value of the relative error of the pulverized coal is about 1.5% and that of the biomass is about 2.2%.

Volatiles and char combustion rates of demineralised lignite and wood blends

International Nuclear Information System (INIS)

Yilgin, Melek; Pehlivan, Dursun

2009-01-01

Today, much interest is given to the utilisation of materials of plant origin as substitutions of fossil fuels in meeting energy needs to reduce the level of atmospheric pollutant emissions and global warming threat, and emphasis has been placed on the co-combustion of coal and biomass. In this study, volatiles and char combustion behaviour of the fuel pellets composed from demineralised lignite and poplar wood sawdust, were investigated in a cylindrical wire mesh basket placed in a preheated tube furnace. The results have shown that ignition times of the pellets decreased with the burning temperature and shortened further due to demineralisation of lignite. Volatiles combustion rates of the samples did not correlate well with combustion times. However, they can be correlated with their respective proximate volatile matter contents. Char burnout times decreased with increasing combustion rates and correlated well with the respective proximate fixed carbon contents of the samples. Deviations were more considerable in the case of rate data. (author)

Life cycle assessment of alternative sewage sludge disposal methods; Oekobilanz von Klaerschlammentsorgungsalternativen

Energy Technology Data Exchange (ETDEWEB)

Fehrenbach, H. [Institut fuer Energie- und Umweltforschung (ifeu), Heidelberg (Germany)

1994-10-01

At present there are three principal options for sewage sludge disposal in use or under discussion: agricultural utilisation - landfilling - cold pretreatment prior to disposal or utilisation (e.g., composting or fermentation) - thermal pretreatment prior to disposal or utilisation (e.g., monocombustion, co-combustion, pyrolysis, gasification). 10% of sewage sludge is currently combusted, 60% is landfilled, and 30% is used for agriculture. The ifeu Institute has carried out several studies which examine and compare the environmental impact of sewage sludge disposal options. [Deutsch] Zur Entsorgung bzw. Verwertung von Klaerschlamm stehen derzeit drei grundsaetzliche Optionen in Anwendung oder werden diskutiert: - Landwirtschaftliche Verwertung - Deponierung - kalte Vorbehandlung vor Deponierung oder Verwertung (z.B. Kompostierung oder Vergaerung) - thermische Vorbehandlung vorn Deponierung oder Verwertung (z.B. Mono- oder Mitverbrennung, Pyrolyse, Vergasung). Verbrannt werden gegenwaertig etwa 10%, 60% deponiert und 30% landwirschaftlich verwertet. Das ifeu-Institut hat in verschiedenen Arbeiten die Umweltauswirkungen von Klaerschlammentsorgungsoptionen untersucht und gegenuebergestellt. (orig./SR)

An appraisal of the properties of bottom waste obtained from bio-mass congestion to estimate the ways of its environmental use

Directory of Open Access Journals (Sweden)

Śliwka Małgorzata

2017-06-01

Full Text Available The bottom waste obtained from bio-mass burning shows a huge variability of chemical and physical properties, depending on the kind of bio-mass, the type of a cauldron and burning parameters. The huge variability of the bottom ashes from the incineration plant and co-combustion of bio-mass makes it difficult to find any way to its management. In reality, only the bottom ashes from coal combustion and the small amount from lignite combustion are used, mainly in the building industry and in mining industry. The article presents the initial research, concerning the estimation of the properties of the bottom ashes obtained from bio-mass congestion in the fluidized-bed boiler to use them safely for the environment. To determine the influence of the tested waste on plants, a number of pot experiments have been conducted. The plants which have been used are recommended for phytotoxicity estimation, and are also used for biological reclamation.

Autothermal upgrading of biomass and wastes for clean and efficient production of power

Energy Technology Data Exchange (ETDEWEB)

Rafal Kobylecki; Zbigniew Bis; Wojciech Nowak [Czestochowa University of Technology (Poland)

2005-07-01

In this paper it is demonstrated that the main barrier of large scale heat and electricity production from biomass may be significantly reduced or eliminated by fuel upgrading and thermal treatment in a specially-designed pilot plant autothermal reactor. The process does not require significant amount of additional energy, since the whole process is run autothermal. The process final products are hot flue gases and a solid residue called a 'biocarbon' of LHV of roughly 28 MJ/kg. The properties of the biocarbon were similar, regardless of the input raw fuel type (biomass, waste, sewage sludge, energy crops, etc.). The use of the biocarbon for direct co-combustion with coal does not require installation of any additional feeding or fuel treatment systems at the power plants. Apart from its possible direct combustion, the biocarbon can be also efficiently used as a promising solid energy carrier for other processes (e.g. fuel cells). 6 refs., 6 figs.

Chemical, structural and combustion characteristics of carbonaceous products obtained by hydrothermal carbonization of palm empty fruit bunches.

Science.gov (United States)

Parshetti, Ganesh K; Kent Hoekman, S; Balasubramanian, Rajasekhar

2013-05-01

A carbon-rich solid product, denoted as hydrochar, was synthesized by hydrothermal carbonization (HTC) of palm oil empty fruit bunch (EFB), at different pre-treatment temperatures of 150, 250 and 350 °C. The conversion of the raw biomass to its hydrochar occurred via dehydration and decarboxylation processes. The hydrochar produced at 350 °C had the maximum energy-density (>27 MJ kg(-1)) with 68.52% of raw EFB energy retained in the char. To gain a detailed insight into the chemical and structural properties, carbonaceous hydrochar materials were characterized by FE-SEM, FT-IR, XRD and Brunauer-Emmett-Teller (BET) analyses. This work also investigated the influence of hydrothermally treated hydrochars on the co-combustion characteristics of low rank Indonesian coal. Conventional thermal gravimetric analysis (TGA) parameters, kinetics and activation energy of different hydrochar and coal blends were estimated. Our results show that solid hydrochars improve the combustion of low rank coals for energy generation. Copyright © 2012 Elsevier Ltd. All rights reserved.

The effect of coal sulfur on the behavior of alkali metals during co-firing biomass and coal

Energy Technology Data Exchange (ETDEWEB)

Tianhua Yang; Xingping Kai; Yang Sun; Yeguang He; Rundong Li [Shenyang Aerospace University, Liaoning (China). Liaoning Key Laboratory of Clean Energy and Institute of Clean Energy and Environmental Engineering

2011-07-15

Biomass contains high amounts of volatile alkali metals and chlorine, which can cause deposition, corrosion and agglomeration during combustion. Meanwhile coal contains a certain amount of sulfur that produces serious environmental pollution following combustion. To investigate the effects of sulfur on the migration of alkali metals during biomass and coal co-combustion, thermodynamic equilibrium calculations were applied and experiments were performed in a laboratory scale reactor combining with a scanning electron microscope (SEM), X-ray powder diffraction (XRD) and other analytical approaches. The results indicate that inorganic sulfur FeS{sub 2} addition significantly enhanced the formation of potassium sulfate when the S/K molar ratio was less than 2. Meanwhile increasing FeS{sub 2} dosage reduced the formation of KCl(g) and KOH(g) and increased the release of HCl(g). In addition potassium sulfate can react with silica and aluminum to form potassium aluminosilicates and release HCl at the S/K molar ratio above 4. 18 refs., 9 figs., 1 tab.

Combustion characteristics and retention-emission of selenium during co-firing of torrefied biomass and its blends with high ash coal.

Science.gov (United States)

Ullah, Habib; Liu, Guijian; Yousaf, Balal; Ali, Muhammad Ubaid; Abbas, Qumber; Zhou, Chuncai

2017-12-01

The combustion characteristics, kinetic analysis and selenium retention-emission behavior during co-combustion of high ash coal (HAC) with pine wood (PW) biomass and torrefied pine wood (TPW) were investigated through a combination of thermogravimetric analysis (TGA) and laboratory-based circulating fluidized bed combustion experiment. Improved ignition behavior and thermal reactivity of HAC were observed through the addition of a suitable proportion of biomass and torrefied. During combustion of blends, higher values of relative enrichment factors in fly ash revealed the maximum content of condensing volatile selenium on fly ash particles, and depleted level in bottom ash. Selenium emission in blends decreased by the increasing ratio of both PW and TPW. Higher reductions in the total Se volatilization were found for HAC/TPW than individual HAC sample, recommending that TPW have the best potential of selenium retention. The interaction amongst selenium and fly ash particles may cause the retention of selenium. Copyright © 2017 Elsevier Ltd. All rights reserved.

Thermal oxidation of biosolids : the green technology has come of age in large cities[Manure, biosolids, and organic industrial/commercial residuals in land applications programs : improving beneficial reuse and protection of water quality

Energy Technology Data Exchange (ETDEWEB)

Puchajda, B.; Oleszkiewicz, J. [Manitoba Univ., Winnipeg, MB (Canada). Dept. of Civil Engineering

2007-07-01

Biosolids management and disposal that is safe and effective by public standards is difficult, particularly for large communities. Land application, landfilling and thermal oxidation with energy recovery (TOER) are the three most popular forms of solids disposal. This paper focused on different aspects of the TOER technology such as energy recovery; air pollution; volume reduction; impact of solids management on waste water treatment plants; process economics; ash residue management; and recycling of nutrients and heavy metals. The thermal oxidation process was described in detail. Societal and environmental impacts were also identified and common factors in mono-incineration, co-combustion and alternative thermal process technologies were presented. The paper also provided examples of successfully operating incineration installations in Europe and North America. It was concluded that the key assets of TOER include volume reduction; decreased liability and product safety; and beneficial use of ash in construction, with future potential for metals and phosphorus recovery. 32 refs., 2 tabs., 12 figs.

Issues in waste combustion

Energy Technology Data Exchange (ETDEWEB)

Gustavsson, Lennart; Robertson, Kerstin; Tullin, Claes [Swedish National Testing and Research Inst., Boraas (Sweden); Sundquist, Lena; Wrangensten, Lars [AaF-Energikonsult AB, Stockholm (Sweden); Blom, Elisabet [AaF-Processdesign AB, Stockholm (Sweden)

2003-05-01

The main purpose of this review is to provide an overview of the state-of-the-art on research and development issues related to waste combustion with relevance for Swedish conditions. The review focuses on co-combustion in grate and fluidised bed furnaces. It is primarily literature searches in relevant databases of scientific publications with to material published after 1995. As a complement, findings published in different report series, have also been included. Since the area covered by this report is very wide, we do not claim to cover the issues included completely and it has not been possitile to evaluate the referred studies in depth. Basic knowledge about combustion issues is not included since such information can be found elsewhere in the literature. Rather, this review should be viewed as an overview of research and development in the waste-to-energy area and as such we hope that it will inspire scientists and others to further work in relevant areas.

Combustion of municipal solid wastes with oil shale in a circulating fluidized bed. Final report

Energy Technology Data Exchange (ETDEWEB)

NONE

1996-06-30

The problem addressed by our invention is that of municipal solid waste utilization. The dimensions of the problem can be visualized by the common comparison that the average individual in America creates in five years time an amount of solid waste equivalent in weight to the Statue of Liberty. The combustible portion of the more than 11 billion tons of solid waste (including municipal solid waste) produced in the United States each year, if converted into useful energy, could provide 32 quads per year of badly needed domestic energy, or more than one-third of our annual energy consumption. Conversion efficiency and many other factors make such a production level unrealistic, but it is clear that we are dealing with a very significant potential resource. This report describes research pertaining to the co-combustion of oil shale with solid municipal wastes in a circulating fluidized bed. The oil shale adds significant fuel content and also constituents that can possible produce a useful cementitious ash.

Energy implications of mechanical and mechanical–biological treatment compared to direct waste-to-energy

International Nuclear Information System (INIS)

Cimpan, Ciprian; Wenzel, Henrik

2013-01-01

Highlights: • Compared systems achieve primary energy savings between 34 and 140 MJ primary /100 MJ input waste. • Savings magnitude is foremost determined by chosen primary energy and materials production. • Energy consumption and process losses can be upset by increased technology efficiency. • Material recovery accounts for significant shares of primary energy savings. • Direct waste-to-energy is highly efficient if cogeneration (CHP) is possible. - Abstract: Primary energy savings potential is used to compare five residual municipal solid waste treatment systems, including configurations with mechanical (MT) and mechanical–biological (MBT) pre-treatment, which produce waste-derived fuels (RDF and SRF), biogas and/or recover additional materials for recycling, alongside a system based on conventional mass burn waste-to-energy and ash treatment. To examine the magnitude of potential savings we consider two energy efficiency levels (state-of-the-art and best available technology), the inclusion/exclusion of heat recovery (CHP vs. PP) and three different background end-use energy production systems (coal condensing electricity and natural gas heat, Nordic electricity mix and natural gas heat, and coal CHP energy quality allocation). The systems achieved net primary energy savings in a range between 34 and 140 MJ primary /100 MJ input waste , in the different scenario settings. The energy footprint of transportation needs, pre-treatment and reprocessing of recyclable materials was 3–9.5%, 1–18% and 1–8% respectively, relative to total energy savings. Mass combustion WtE achieved the highest savings in scenarios with CHP production, nonetheless, MBT-based systems had similarly high performance if SRF streams were co-combusted with coal. When RDF and SRF was only used in dedicated WtE plants, MBT-based systems totalled lower savings due to inherent system losses and additional energy costs. In scenarios without heat recovery, the biodrying MBS

Energy implications of mechanical and mechanical–biological treatment compared to direct waste-to-energy

Energy Technology Data Exchange (ETDEWEB)

Cimpan, Ciprian, E-mail: cic@kbm.sdu.dk; Wenzel, Henrik

2013-07-15

Highlights: • Compared systems achieve primary energy savings between 34 and 140 MJ{sub primary}/100 MJ{sub input} {sub waste.} • Savings magnitude is foremost determined by chosen primary energy and materials production. • Energy consumption and process losses can be upset by increased technology efficiency. • Material recovery accounts for significant shares of primary energy savings. • Direct waste-to-energy is highly efficient if cogeneration (CHP) is possible. - Abstract: Primary energy savings potential is used to compare five residual municipal solid waste treatment systems, including configurations with mechanical (MT) and mechanical–biological (MBT) pre-treatment, which produce waste-derived fuels (RDF and SRF), biogas and/or recover additional materials for recycling, alongside a system based on conventional mass burn waste-to-energy and ash treatment. To examine the magnitude of potential savings we consider two energy efficiency levels (state-of-the-art and best available technology), the inclusion/exclusion of heat recovery (CHP vs. PP) and three different background end-use energy production systems (coal condensing electricity and natural gas heat, Nordic electricity mix and natural gas heat, and coal CHP energy quality allocation). The systems achieved net primary energy savings in a range between 34 and 140 MJ{sub primary}/100 MJ{sub input} {sub waste}, in the different scenario settings. The energy footprint of transportation needs, pre-treatment and reprocessing of recyclable materials was 3–9.5%, 1–18% and 1–8% respectively, relative to total energy savings. Mass combustion WtE achieved the highest savings in scenarios with CHP production, nonetheless, MBT-based systems had similarly high performance if SRF streams were co-combusted with coal. When RDF and SRF was only used in dedicated WtE plants, MBT-based systems totalled lower savings due to inherent system losses and additional energy costs. In scenarios without heat

Cocombustion of biomass in coal-fired power plants; Meestoken van biomassa in kolengestookte E-centrales

Energy Technology Data Exchange (ETDEWEB)

Albrink, W.G.M. [Stork Thermeq, Hengelo (Netherlands)

2001-12-01

The aim of the desk study is to determine to what degree several types of biomass can be cofired with existing coal fired utility boilers in the Netherlands. All results with regard to boiler performances are obtained by making use of a computer model of a typical coal fired boiler which make part of a 600 MWe coal fired power plant. Because the existing coal fired units in the Netherlands do deviate more or less from the used model all outcomes and conclusions of this study are indicative. Slagging and corrosion which become more important when firing biogas in a coal fired boiler are considered superficially. More close investigations are necessary when carry out concrete projects. Furthermore all results are based on 100% boiler load and may not be used or extrapolated to part load conditions. The extent of firing biomass gas may depend on available space in the boiler house and correlated restrictions for necessary constructive adaptations. These aspects were leave out of consideration. For information the necessary size of piping for biomass gas from gasifier to the boiler has been determined for several amounts of biomass. [Dutch] Het doel van de studie is te onderzoeken hoeveel biomassa, in percentage van het thermisch vermogen, volgens verschillende concepten kan worden meegestookt in een kolengestookte elektriciteitscentrale. Dit wordt in deze studie behandeld aan de hand van een aantal aspecten: Rookgashoeveelheden door de ketel. Hierbij kornen de volgende zaken aan de orde: snelheden, drukval, belasting van DeNox, DeSox en E-filters, capaciteit van de ventilatoren; Rookgastemperaturen. Dit betreft temperaturen uitlaat vuurhaard, uitlaat ketel en uitlaat LUVO (luchtverhitter); Verslakking en corrosie van oververhitters; Water/stoomzijdige flows. Dit betreft aspecten als flows, temperaturen, flow door de turbine (slikvermogen) en uitlaatconditie stoomturbine (vochtgehalte). Voor de verwerking van biomassa worden alleen vergassing (in hoofdzaak) en, minder uitgebreid, verbranding in een CFBC (circulating fluidized bed combustor) beschouwd.

EMISSIONS FROM CO-COMBUSTION OF COAL AND MUNICIPAL SOLID WASTE IN DOMESTIC CENTRAL HEATING BOILER

Directory of Open Access Journals (Sweden)

Ewelina Maria Cieślik

2017-04-01

The results were analyzed in terms of combustion efficiency, emissions of major pollutants (NOx, CO, SO2 and fly ash with adsorbed of PAHs on its surface. The average concentration of emitted particulate matter was 764 mg m-3, and CO - 1944, SO2 - 1256 NOx - 555 mg m-3 (STP, 3% O2, dry gas. The flue gases contain fly ash, with a significant carbon content EC (average 31% and a high proportion of PM10 and PM2.5 - respectively 100 and 75% by volume.

Economic and environmental assessment of cellulosic ethanol production scenarios annexed to a typical sugar mill.

Science.gov (United States)

Ali Mandegari, Mohsen; Farzad, Somayeh; Görgens, Johann F

2017-01-01

In this work different biorefinery scenarios were investigated, concerning the co-production of bioethanol and electricity from available lignocellulose at a typical sugar mill, as possible extensions to the current combustion of bagasse for steam and electricity production and burning trash on-filed. In scenario 1, the whole bagasse and brown leaves is utilized in a biorefinery and coal is burnt in the existing inefficient sugar mill boiler. Scenario 2 & 3 are assumed with a new centralized CHP unit without/with coal co-combustion, respectively. Also, through scenarios 4 & 5, the effect of water insoluble loading were studied. All scenarios provided energy for the sugarmill and the ethanol plant, with the export of surplus electricity. Economic analysis determined that scenario 1 was the most viable scenario due to less capital cost and economies-of scale. Based on Life Cycle Assessment (LCA) results, scenario 2 outperformed the other scenarios, while three scenarios showed lower contribution to environmental burdens than the current situation. Copyright © 2016 Elsevier Ltd. All rights reserved.

The importance of SO{sub 2} and SO{sub 3} for sulphation of gaseous KCl - An experimental investigation in a biomass fired CFB boiler

Energy Technology Data Exchange (ETDEWEB)

Kassman, Haakan [Vattenfall Power Consultant AB, Nykoeping (Sweden); Chalmers University of Technology, Department of Energy and Environment, Division of Energy Technology, Gothenburg (Sweden); Baefver, Linda [Technical Research Institute of Sweden, Energy Technology, Boraas (Sweden); Aamand, Lars-Erik [Chalmers University of Technology, Department of Energy and Environment, Division of Energy Technology, Gothenburg (Sweden)

2010-09-15

This paper is based on results obtained during co-combustion of wood pellets and straw in a 12 MW circulating fluidised bed (CFB) boiler. Elemental sulphur (S) and ammonium sulphate ((NH{sub 4}){sub 2}SO{sub 4}) were used as additives to convert the alkali chlorides (mainly KCl) to less corrosive alkali sulphates. Their performance was then evaluated using several measurement tools including, IACM (on-line measurements of gaseous alkali chlorides), a low-pressure impactor (particle size distribution and chemical composition of extracted fly ash particles), and deposit probes (chemical composition in deposits collected). The importance of the presence of either SO{sub 2} or SO{sub 3} for gas phase sulphation of KCl is also discussed. Ammonium sulphate performed significantly better than elemental sulphur. A more efficient sulphation of gaseous KCl was achieved with (NH{sub 4}){sub 2}SO{sub 4} even when the S/Cl molar ratio was less than half compared to sulphur. Thus the presence of gaseous SO{sub 3} is of greater importance than that of SO{sub 2} for the sulphation of gaseous KCl. (author)

Study of toxic metals during combustion of RDF in a fluidized bed pilot

Energy Technology Data Exchange (ETDEWEB)

Crujeira, T.; Lopes, H.; Abelha, P.; Sargaco, C.; Goncalves, R.; Freire, M.; Cabrita, I.; Gulyurtlu, I. [DEECA, INETI, Lisbon (Portugal)

2005-04-01

The study of the behavior of heavy metals during combustion of refuse-derived fuel (RDF) in a pilot fluidized bed was performed. The results of co-combustion were compared with coal combustion and RDF monocombustion. The amounts of heavy metals retained by the ash were different during co-firing in comparison with monocombustion due to the mechanisms leading to different partitioning of ash. It was verified that heavy metal emissions increased with introduction of RDF, but remained below regulated levels, with the exception of chromium (Cr) and nickel (Ni). For RDF monocombustion the emissions were, however, more severe, especially for cadmium (Cd), lead (Pb), and copper (Cu). This seems to be related not only to larger input amounts, but also to higher volatilisation during monocombustion caused by the presence of higher chlorine and lower sulphur contents in the RDF. Hence, as far as heavy metals are concerned, the utilization of RDF as a co-firing combustible for coal seems to be more environmental favorable than when RDF is fired alone.

Thermal Analysis of Solid Fuels in an Inert Atmosphere

Science.gov (United States)

Kijo-Kleczkowska, Agnieszka; Szumera, Magdalena; Środa, Katarzyna

2017-12-01

The paper takes the analysis of thermal studies of different types of fuels. It allowed diversification of fuels depending on their composition and origin. Consideration of coal, biomass and waste (coal mule, sewage sludge) as fuel is nowadays an important aspect of energy in our country. It should be emphasized that Poland power engineering is based up to 95% on coal - the primary fuel. Mining industry, forced to deliver power engineering more and better fuel, must however, use a deeper cleaning of coal. This results in a continuous increase waste in the form of mule flotation. The best method of disposing these mule is combustion and co-combustion with other fuels. On the other hand, commonly increasing awareness state of the environment and the need to reduce CO2 emissions energy industry have committed to implement alternative solutions in order to gain power, through, i.a.: development technologies use of biomass, which is one of the most promising renewable energy sources in Poland. The paper presents the results of research TG-DTA fuels made in an inert atmosphere.

Migration and transformation of sulfur in the municipal sewage sludge during disposal in cement kiln.

Science.gov (United States)

Huang, Yuyan; Li, Haoxin; Jiang, Zhengwu; Yang, Xiaojie; Chen, Qing

2018-05-07

The aim of this work was to investigate the migration and transformation of sulfur in the municipal sewage sludge during disposal in cement kiln, and better understand the emission of the sulfur related pollutants in this process. In consideration of the temperature conditions in the practical operation, municipal sewage sludge was pre-dried at 105 °C, and then dried at 210, 260 and 310 °C, co-combusted with cement raw mill at 800, 900 and 1000 °C, and 1350, 1400 and 1450 °C respectively in the laboratory. X-ray photoelectron spectroscopy (XPS) was used to determine the S2p spectral lines of the municipal sewage sludge treated in the different process. Besides, The Thermal Analysis-Thermogravimetry (DTA-TG), Back Scattered Electron (BSE) and Energy Dispersive Spectrometer (EDS) were also employed to explore the mechanism of sulfur subsistence at 1450 °C. The results indicate that sulfide, thiophene, sulfone and sulfate are mainly sulfur compound in the municipal sewage sludge dried at 105 °C. Sulfoxide, a new sulfur compound, appears after it is further dried at 210 °C. The relative contents of sulfide and thiophene are continuously declined as the drying temperature increases due to their evaporation, decomposition and transformation in this process. The transformation of sulfide and thiophene makes the relative contents of sulfoxide and sulfate accordingly increased. However, the relative content of sulfone experiences an elevating-lowering process while the dry temperature elevated from 210 to 310 °C. This case is related to its evaporation and decomposition, as well as its production for the transformation of sulfide and thiophene. In the co-combustion process, sulfide, thiophene and sulfone are entirely vanished for their evaporation, decomposition and transformation. Sulfone is still contained at 800 °C, but when the temperature unceasingly rises, it is completely decomposed or evaporated and sulfate is the only sulfur compound. The

Use of co-combustion bottom ash to design an acoustic absorbing material for highway noise barriers

International Nuclear Information System (INIS)

Arenas, Celia; Leiva, Carlos; Vilches, Luis F.; Cifuentes, Héctor

2013-01-01

Highlights: • The particle size of bottom ash influenced the acoustic behavior of the barrier. • The best sound absorption coefficients were measured for larger particle sizes. • The maximum noise absorption is displaced to lower frequencies for higher thickness. • A noise barrier was designed with better properties than commercial products. • Recycling products from bottom ash no present leaching and radioactivity problems. - Abstract: The present study aims to determine and evaluate the applicability of a new product consisting of coal bottom ash mixed with Portland cement in the application of highway noise barriers. In order to effectively recycle the bottom ash, the influence of the grain particle size of bottom ash, the thickness of the panel and the combination of different layers with various particle sizes have been studied, as well as some environmental properties including leachability (EN-12457-4, NEN-7345) and radioactivity tests. Based on the obtained results, the acoustic properties of the final composite material were similar or even better than those found in porous concrete used for the same application. According to this study, the material produced presented no environmental risk

Use of co-combustion bottom ash to design an acoustic absorbing material for highway noise barriers

Energy Technology Data Exchange (ETDEWEB)

Arenas, Celia; Leiva, Carlos; Vilches, Luis F. [University of Seville, School of Industrial Engineering, Department of Chemical and Environmental Engineering, Camino de los Descubrimientos s/n, E-41092 Seville (Spain); Cifuentes, Héctor, E-mail: bulte@us.es [University of Seville, School of Industrial Engineering, Continuum Mechanics and Structural Analysis Department, Camino de los Descubrimientos s/n, E-41092 Seville (Spain)

2013-11-15

Highlights: • The particle size of bottom ash influenced the acoustic behavior of the barrier. • The best sound absorption coefficients were measured for larger particle sizes. • The maximum noise absorption is displaced to lower frequencies for higher thickness. • A noise barrier was designed with better properties than commercial products. • Recycling products from bottom ash no present leaching and radioactivity problems. - Abstract: The present study aims to determine and evaluate the applicability of a new product consisting of coal bottom ash mixed with Portland cement in the application of highway noise barriers. In order to effectively recycle the bottom ash, the influence of the grain particle size of bottom ash, the thickness of the panel and the combination of different layers with various particle sizes have been studied, as well as some environmental properties including leachability (EN-12457-4, NEN-7345) and radioactivity tests. Based on the obtained results, the acoustic properties of the final composite material were similar or even better than those found in porous concrete used for the same application. According to this study, the material produced presented no environmental risk.

Use of co-combustion bottom ash to design an acoustic absorbing material for highway noise barriers.

Science.gov (United States)

Arenas, Celia; Leiva, Carlos; Vilches, Luis F; Cifuentes, Héctor

2013-11-01

The present study aims to determine and evaluate the applicability of a new product consisting of coal bottom ash mixed with Portland cement in the application of highway noise barriers. In order to effectively recycle the bottom ash, the influence of the grain particle size of bottom ash, the thickness of the panel and the combination of different layers with various particle sizes have been studied, as well as some environmental properties including leachability (EN-12457-4, NEN-7345) and radioactivity tests. Based on the obtained results, the acoustic properties of the final composite material were similar or even better than those found in porous concrete used for the same application. According to this study, the material produced presented no environmental risk. Copyright © 2013 Elsevier Ltd. All rights reserved.

Analysis of the danger potential of H2/CO-combustion in the event of core meltdown

International Nuclear Information System (INIS)

Fischer, M.; Wagler, K.; Schwarzott, W.; Reineke, H.H.

1987-01-01

Based on an evaluation of the present state of knowledge and the experiments performed, several computing programs for the simulation of H 2 /CO combustion processes were developed within the scope of this project. Besides the one-compartment-model MOPED, based on the formulation of empirical and phenomenological connections, which was also used later to perform the pressure buildup analyses during various core meltdown (CM) scenarios, these were the first two attempts in respect of a fluid-dynamic description of the combustion processes that also takes the reaction kinetics into account (VERLA code, PISCES code). The analysis of the low (LP) and high (HP) pressure path CM conditions showed that no additional risk arises on the HP path due to potential H 2 combustion. In opposition to this maximum combustion gas fractions of 15% by vol. H 2 and 2.5% by vol. CO with assumption of complete enrichment in the containment result on the LP path. With 37 refs., 3 tabs., 78 figs [de

Thermogravimetric analysis of the behavior of sub-bituminous coal and cellulosic ethanol residue during co-combustion.

Science.gov (United States)

Buratti, C; Barbanera, M; Bartocci, P; Fantozzi, F

2015-06-01

The influence of the addition of cellulosic ethanol residue (CER) on the combustion of Indonesian sub-bituminous coal was analyzed by non isothermal thermo-gravimetric analysis (TGA). The effect of blends ratio (5%, 10%, 15% and 20%), interaction mechanism, and heating rate (5°C/min, 10°C/min, 15°C/min, 20°C/min) on the combustion process was studied. The results show that the increase of the blending ratio allows to achieve the increase of the combustibility index from 7.49E-08 to 5.26E-07 at the blending ratio of 20%. Two types of non-isothermal kinetic analysis methods (Ozawa-Flynn-Wall and Vyazovkin) were also applied. Results indicate that the activation energy of the blends decreases with increasing the conversion rate. In particular, the blending ratio of 20% confirms to have the better combustion performance, with the average value of the activation energy equal to 41.10 kJ/mol obtained by Ozawa-Flynn-Wall model and 31.17 kJ/mol obtained by Vyazovkin model. Copyright © 2015 Elsevier Ltd. All rights reserved.

Use of pyrolysis gases from biogenic fuels as reductionfuels in coal dust furnaces; Einsatz von Pyrolysegasen aus biogenen Brennstoffen als Reduktionsbrennstoff in Kohlestaubfeuerungen

Energy Technology Data Exchange (ETDEWEB)

Ruediger, H; Greul, U; Spliethoff, H; Hein, K R.G. [Stuttgart Univ. (Germany). Inst. fuer Verfahrenstechnik und Dampfkesselwesen (IVD)

1997-12-31

Co-combustion of refuse-derived fuels in the form of pyrolysis gases, with coal as primary fuel, has advantages in terms of fuel ash separation and nitric oxide emissions. Biomass or sewage sludge is degassed in a pyrolysis reactor, and the gas is used as secondary fuel in a coal dust furnace. The authors investigated the influence of reaction temperature, fuel moisture and reaction atmosphere in the pyrolysis stage on the product fractions gas, tar, and residual fuel, as well as the suitability of the resulting pyrolysis gas as secondary fuel in a coal dust furnace for the purpose of reducing nitric oxide emissions. (orig) [Deutsch] Ein am IVD betriebenes Konzept der Mitverbrennung von Brennstoffen in Form von Pyrolysegasen bietet Vorteile bezueglich der Trennung der Brennstoffaschen und Stickoxidemissionen bei der Feuerung des Primaerbrennstoffes Steinkohle. Biomasse oder Klaerschlamm wird hierbei in einem Pyrolysereaktor engast und gasfoermig als Sekundaerbrennstoff in einer Kohlenstaubfeuerung eingesetzt. Untersuchungsschwerpunkte in der Pyrolysestufe des Prozesses waren die Einfluesse von Reaktionstemperatur, Brennstofffeuchte und Reaktionsatmosphaere auf die Produktfraktionen Gas, Teer und Restbrennstoff sowie die Eignung des erzeugten Pyrolysegases als Sekundaerbrennstoff in einer Kohlenstaubfeuerung zur Senkung derKohlendioxidemissione. (orig)

Use of pyrolysis gases from biogenic fuels as reductionfuels in coal dust furnaces; Einsatz von Pyrolysegasen aus biogenen Brennstoffen als Reduktionsbrennstoff in Kohlestaubfeuerungen

Energy Technology Data Exchange (ETDEWEB)

Ruediger, H.; Greul, U.; Spliethoff, H.; Hein, K.R.G. [Stuttgart Univ. (Germany). Inst. fuer Verfahrenstechnik und Dampfkesselwesen (IVD)

1996-12-31

Co-combustion of refuse-derived fuels in the form of pyrolysis gases, with coal as primary fuel, has advantages in terms of fuel ash separation and nitric oxide emissions. Biomass or sewage sludge is degassed in a pyrolysis reactor, and the gas is used as secondary fuel in a coal dust furnace. The authors investigated the influence of reaction temperature, fuel moisture and reaction atmosphere in the pyrolysis stage on the product fractions gas, tar, and residual fuel, as well as the suitability of the resulting pyrolysis gas as secondary fuel in a coal dust furnace for the purpose of reducing nitric oxide emissions. (orig) [Deutsch] Ein am IVD betriebenes Konzept der Mitverbrennung von Brennstoffen in Form von Pyrolysegasen bietet Vorteile bezueglich der Trennung der Brennstoffaschen und Stickoxidemissionen bei der Feuerung des Primaerbrennstoffes Steinkohle. Biomasse oder Klaerschlamm wird hierbei in einem Pyrolysereaktor engast und gasfoermig als Sekundaerbrennstoff in einer Kohlenstaubfeuerung eingesetzt. Untersuchungsschwerpunkte in der Pyrolysestufe des Prozesses waren die Einfluesse von Reaktionstemperatur, Brennstofffeuchte und Reaktionsatmosphaere auf die Produktfraktionen Gas, Teer und Restbrennstoff sowie die Eignung des erzeugten Pyrolysegases als Sekundaerbrennstoff in einer Kohlenstaubfeuerung zur Senkung derKohlendioxidemissione. (orig)

Assessing fly ash treatment: remediation and stabilization of heavy metals.

Science.gov (United States)

Lima, A T; Ottosen, Lisbeth M; Ribeiro, Alexandra B

2012-03-01

Fly ashes from Municipal Solid Waste (MSW), straw (ST) and co-combustion of wood (CW) are here analyzed with the intent of reusing them. Two techniques are assessed, a remediation technique and a solidification/stabilization one. The removal of heavy metals from fly ashes through the electrodialytic process (EDR) has been tried out before. The goal of removing heavy metals has always been the reuse of fly ash, for instance in agricultural fields (BEK). The best removal rates are here summarized and some new results have been added. MSW fly ashes are still too hazardous after treatment to even consider application to the soil. ST ash is the only residue that gets concentrations low enough to be reused, but its fertilizing value might be questioned. An alternative reuse for the three ashes is here preliminary tested, the combination of fly ash with mortar. Fly ashes have been substituted by cement fraction or aggregate fraction. Surprisingly, better compressive strengths were obtained by replacing the aggregate fraction. CW ashes presented promising results for the substitution of aggregate in mortar and possibly in concrete. Copyright © 2010 Elsevier Ltd. All rights reserved.

Comparison of coal/solid recovered fuel (SRF) with coal/refuse derived fuel (RDF) in a fluidised bed reactor

International Nuclear Information System (INIS)

Wagland, S.T.; Kilgallon, P.; Coveney, R.; Garg, A.; Smith, R.; Longhurst, P.J.; Pollard, S.J.T.; Simms, N.

2011-01-01

An experimental study was undertaken to compare the differences between municipal solid waste (MSW) derived solid recovered fuel (SRF) (complying with CEN standards) and refuse derived fuel (RDF). Both fuels were co-combusted with coal in a 50 kW fluidised bed combustor and the metal emissions were compared. Synthetic SRF was prepared in the laboratory by grinding major constituents of MSW such as paper, plastic, textile and wood. RDF was obtained from a local mechanical treatment plant. Heavy metal emissions in flue gas and ash samples from the (coal + 10% SRF) fuel mixture were found to be within the acceptable range and were generally lower than that obtained for coal + 10% RDF fuel mixture. The relative distribution of heavy metals in ash components and the flue gas stream shows the presence of a large fraction (up to 98%) of most of the metals in the ash (except Hg and As). Thermo-gravimetric (TG) analysis of SRF constituents was performed to understand the behaviour of fuel mixtures in the absence and presence of air. The results obtained from the experimental study will enhance the confidence of fuel users towards using MSW-derived SRF as an alternative fuel.

Progress in the treatment of MSW in TOP

International Nuclear Information System (INIS)

Mohd Noor Mohd Yunus; Mohamed, Z.; Kumar, R.

2000-01-01

The solid waste management is getting very critical in Malaysia as the present landfill practice does not resolve the ever-growing amount of Municipal Solid Waste (MSW) generated especially in the urban areas. As such, the Government of Malaysia has decided to adopt thermal treatment method, in particular the gasification technology, due to superior emission control to solve this problem. The gasification technology is, however, very new, emerging, costly and fully imported. Upon realizing this, a simpler fixed bed gasification plant, called the Thermal Oxidation Plant (TOP), was acquired and installed in MINT, aimed at assessing the technology to be applied for MSW treatment. The performance, especially the emission, of this plant was examined and found to be very good. However, one of the weaknesses noted is on the level of HCl emitted, which at times exceeded the emission standard. A suggestion was made to improve this by Co-Combusting MSW with Malaysia Oil Palm Shell (MOPS), since the charcoal derived from MOPS is believed to be able to adsorb acidic gases in situ at the prevailing furnace condition. Early result shows some promise, especially the development of porosity in the charcoal derived from MOPS

Assessing fly ash treatment: Remediation and stabilization of heavy metals

KAUST Repository

Lima, A.T.

2010-12-17

Fly ashes from Municipal Solid Waste (MSW), straw (ST) and co-combustion of wood (CW) are here analyzed with the intent of reusing them. Two techniques are assessed, a remediation technique and a solidification/stabilization one. The removal of heavy metals from fly ashes through the electrodialytic process (EDR) has been tried out before. The goal of removing heavy metals has always been the reuse of fly ash, for instance in agricultural fields (BEK). The best removal rates are here summarized and some new results have been added. MSW fly ashes are still too hazardous after treatment to even consider application to the soil. ST ash is the only residue that gets concentrations low enough to be reused, but its fertilizing value might be questioned. An alternative reuse for the three ashes is here preliminary tested, the combination of fly ash with mortar. Fly ashes have been substituted by cement fraction or aggregate fraction. Surprisingly, better compressive strengths were obtained by replacing the aggregate fraction. CW ashes presented promising results for the substitution of aggregate in mortar and possibly in concrete. © 2010 Elsevier Ltd.

Integration of torrefaction in CHP plants – A case study

International Nuclear Information System (INIS)

Starfelt, Fredrik; Tomas Aparicio, Elena; Li, Hailong; Dotzauer, Erik

2015-01-01

Highlights: • We model the integration of a torrefaction reactor in a CHP plant. • Techno-economic analysis for the system is performed. • Flue gas integration of torrefaction show better performance. • Heat or electricity production is not compromised in the proposed system. - Abstract: Torrefied biomass shows characteristics that resemble those of coal. Therefore, torrefied biomass can be co-combusted with coal in existing coal mills and burners. This paper presents simulation results of a case study where a torrefaction reactor was integrated in an existing combined heat and power plant and sized to replace 25%, 50%, 75% or 100% of the fossil coal in one of the boilers. The simulations show that a torrefaction reactor can be integrated with existing plants without compromising heat or electricity production. Economic and sensitivity analysis show that the additional cost for integrating a torrefaction reactor is low which means that with an emission allowance cost of 37 €/ton CO 2 , the proposed integrated system can be profitable and use 100% renewable fuels. The development of subsidies will affect the process economy. The determinant parameters are electricity and fuel prices

Assessing fly ash treatment: Remediation and stabilization of heavy metals

KAUST Repository

Lima, A.T.; Ottosen, Lisbeth M.; Ribeiro, Alexandra B.

2010-01-01

Fly ashes from Municipal Solid Waste (MSW), straw (ST) and co-combustion of wood (CW) are here analyzed with the intent of reusing them. Two techniques are assessed, a remediation technique and a solidification/stabilization one. The removal of heavy metals from fly ashes through the electrodialytic process (EDR) has been tried out before. The goal of removing heavy metals has always been the reuse of fly ash, for instance in agricultural fields (BEK). The best removal rates are here summarized and some new results have been added. MSW fly ashes are still too hazardous after treatment to even consider application to the soil. ST ash is the only residue that gets concentrations low enough to be reused, but its fertilizing value might be questioned. An alternative reuse for the three ashes is here preliminary tested, the combination of fly ash with mortar. Fly ashes have been substituted by cement fraction or aggregate fraction. Surprisingly, better compressive strengths were obtained by replacing the aggregate fraction. CW ashes presented promising results for the substitution of aggregate in mortar and possibly in concrete. © 2010 Elsevier Ltd.

[Inhibition of chlorobenzene formation via various routes during waste incineration by ammonium sulfate and urea].

Science.gov (United States)

Yan, Mi; Qi, Zhi-Fu; Li, Xiao-Dong; Hu, Yan-Jun; Chen, Tong

2014-01-01

Chlorobenzene (CBz) is the precursor of polychlorinated dibenzo-p-dioxins/polychlorinated dibenzofurans (PCDD/Fs) generated in the processes of waste incineration, and it is regarded as a good indicator of PCDD/Fs for realizing PCDD/Fs online monitoring, moreover, pentachlorobenzene (PeCBz) and Hexachlorobenzene (HxCBz) belong to Persistent Organic Pollutants (POPs). However, the emission control of CBz in waste incineration does not attract enough attention, so this study focused on the inhibition of the 3 CBz formation routes in waste combustion by ammonium sulfate and urea, including CB formation from fly ash, CB formation from 1,2-dichlorobenzene (1,2-DiCBz) and the combustion of model medical waste. The results showed that both ammonium sulfate and urea reduced CBz yield during these three thermal processes. For instance, the inhibition rates of tetrachlorobenzene (TeCBz), PeCBz and HxCBz were 66.8%, 57.4% and 50.4%, respectively, when 1% urea was co-combusted with medical waste. By comparing the effect of ammonium sulfate and urea on CBz formation by three routes, urea was considered as a comparatively stable inhibitor for CBz.

Combustion of Refuse Derived Fuels; Foerbraenning av utsorterade avfallsfraktioner

Energy Technology Data Exchange (ETDEWEB)

Berg, Magnus; Wikman, Karin [AaF-Energi och Miljoe, Stockholm (Sweden); Andersson, Christer; Myringer, Aase; Helgesson, Anna [Vattenfall Utveckling AB, Aelvkarleby (Sweden); Eskilsson, David; Ekvall, Annika [SP Swedish National Testing and Research Inst., Boraas (Sweden); Oehman, Marcus; Geyter, Sigrid de [Umeaa Univ. (Sweden). Energy Technology and Thermal Process Chemistry

2005-03-01

the different fuel mixtures shows that addition of PWP-fuel results in locally lower O{sub 2}-levels and higher CO-levels close to the front wall. This results in an increased risk for local corrosion on the furnace walls. The measurements in Johannes showed that co-combustion with PWP increased the alkali chloride concentration in the flue gas but an increase in the amount of deposits could not be measured. However, the deposits contained more chlorine during co-combustion of PWP, which should yield increased risk for corrosion. The increase can be correlated with the wood and paper fractions of the fuel. Injection of sulphate in the furnace resulted in increased SO{sub 2} concentration and reduced alkali chloride concentration, which resulted in reduced deposit formation. Addition of sulphate also reduced the chlorine concentration in the deposits thereby reducing the corrosion risk. The sub micron particles in the flue gas before gas cleaning mainly contain KCl and K2SO{sub 4} but with sulphate addition KCl to a large extent is converted to K{sub 2}SO{sub 4}. Altogether, this shows that this kind of fuel yields an increased risk for corrosion and deposits on superheaters and furnace walls. However, these problems can to a large extent be avoided by the addition of sulphur (concerning superheater corrosion) and adjustment of the air and fuel feed equipment (concerning furnace wall corrosion). Also in the tests in Hoegdalen the SO{sub 2} concentration increased and the alkali chloride concentration decreased in the flue gas when sulphur was added, resulting in decreased deposit formation. At the same time the chlorine concentration decreased and the sulphur concentration increased in the deposits. However, the chlorine concentration of the deposits was still high and did not decrease as much as in Johannes. Using elementary sulphur or sulphate as an additive had no noticeable influence on deposit growth or on the chemical composition of the deposits. Neither did the

Emissions of toxic pollutants from co-combustion of demolition and construction wood and household waste fuel blends.

Science.gov (United States)

Edo, Mar; Ortuño, Núria; Persson, Per-Erik; Conesa, Juan A; Jansson, Stina

2018-07-01

Four different types of fuel blends containing demolition and construction wood and household waste were combusted in a small-scale experimental set-up to study the effect of fuel composition on the emissions of polychlorinated dibenzo-p-dioxins (PCDDs), dibenzofurans (PCDFs), biphenyls (PCBs), chlorobenzenes (PCBzs), chlorophenols (PCPhs) and polycyclic aromatic hydrocarbons (PAHs). Two woody materials, commercial stemwood (ST) and demolition and construction wood (DC) were selected because of the differences in their persistent organic pollutants (POPs), ash and metals content. For household waste, we used a municipal solid waste (MSW) and a refuse-derived fuel (RDF) from MSW with 5-20 wt% and up to 5 wt% food waste content respectively. No clear effect on the formation of pollutants was observed with different food waste content in the fuel blends tested. Combustion of ST-based fuels was very inefficient which led to high PAH emissions (32 ± 3.8 mg/kg fuel ). The use of DC clearly increased the total PCDD and PCDF emissions (71 ± 26 μg/kg fuel ) and had a clear effect on the formation of toxic congeners (210 ± 87 ng WHO 2005 -TEQ/kg fuel ). The high PCDD and PCDF emissions from DC-based fuels can be attributed to the presence of material contaminants such as small pieces of metals or plastics as well as timber treated with chromated copper arsenate preservatives and pentachlorophenol in the DC source. Copyright © 2018 Elsevier Ltd. All rights reserved.

PROCESS OPTIMIZATION OF SAMPLING AND DETERMINING THE UNCERTAINTY ASSOCIATED WITH THE PROPERTIES OF SOLID FUELS FOR COCOMBUSTION

Directory of Open Access Journals (Sweden)

JOSE ANTONIO PAZÓ

2010-01-01

Full Text Available En este trabajo se presenta el proceso empleado para la determinación estadística de la incertidumbre asociada a diversas propiedades de ocho combustibles sólidos para co-combustión a partir de los ensayos de humedad y cenizas. Se establece un mapa de muestreo que permite determinar los tamaños muestrales en función de las incertidumbres que se consideren aceptables. Los valores obtenidos permiten afirmar que a pesar de la heterogeneidad propia de dichos combustibles, una campaña de muestreos bien planificada permite extrapolar las propiedades obtenidas de las muestras a la totalidad del lote analizado con una incertidumbre controlada y cuantificada.

The emissions of VOCs during co-combustion of coal with different waste materials in a fluidized bed

Energy Technology Data Exchange (ETDEWEB)

I. Gulyurtlu; P. Abelha; A. Gregorio; A. Garcia-Garcia; D. Boavida; A. Crujeira; I. Cabrita [DEECA-INETI, Lisbon (Portugal)

2004-06-01

The combustion of different fuels gives rise to the formation of small but appreciable amounts of volatile organic compounds (VOCs). They basically result from incomplete combustion and their emissions have negative repercussions on health and on the environment in general. As their measurement is difficult, costly, and very time-consuming, very little is reported on the emissions of VOCs from combustion installations. In this study, various blends of two different coals with several wastes were burned in a pilot-scale fluidized bed combustor and measurements of VOCs at several locations along the combustor height as well as just before the stack were carried out. The results demonstrate that the parameters important for the formation of VOCs are temperature, excess air levels, and the effectiveness of the mixing of air with fuel. Furthermore, it was observed that coal was the principal source of VOCs, but the combustion of volatiles from fuels such as biomass, occurring in the freeboard, was important in reducing the emissions of VOCs to almost zero. 8 refs., 6 figs., 6 tabs.

Prevention of Bed Agglomeration Problems in a Fluidized Bed Boiler by Finding the Trigging Value of Sewage Sludge Dosage Added to Combustion of Biofuels

Energy Technology Data Exchange (ETDEWEB)

Andersson, Kajsa; Gervind, Pernilla

2009-07-01

Agglomeration of bed sand is a common problem during combustion of biofuels with high ash content in fluidized bed boilers. Former studies have shown that co-combustion of biofuels with sewage sludge increases the agglomeration temperature. Sewage sludge has a low heating value and high ash content. It would therefore be better to use sludge as an additive to the combustion than as a co-combusted biofuel. In this study the trigging value of sludge addition to the combustion of some biofuel was investigated. The effect of adding sludge with different precipitation chemicals, iron sulphate and aluminium sulphate, was investigated. The biofuels used for the experiments were bark, refused derived fuel (RDF) and a mixture of wood and straw, 75/25 % on energy basis. All experiments were carried out in a laboratory scale fluidized bed reactor. Analyses of chemical composition of bed sand and SEM/EDX analyses were performed after the combustion. Eventually agglomeration tests were performed in order to find the agglomeration temperature of the samples. Some of the samples sintered during the combustion and were not tested for the agglomeration temperature. SEM/EDX showed that all samples of bed sand contained sand particles with more or less coatings. In some cases the coatings seemed to consist of one dense inner layer and one more porous outer layer. From SEM/EDX and chemical composition analyses it was found that the total amount of phosphorous in the bed sand samples was increased with an increased addition of sludge in all experiments. The concentration of phosphorous was especially higher in the outer layers/coatings. It was also found that elements from the sludge seem to get caught by a sticky layer at the bed sand surface and form a non-sticky or less sticky layer that prevents agglomeration. The total amount of aluminium was increased with an increased addition of sludge for the wood/straw samples, while it increased with an increased amount of combusted fuel for

Robert Priddle talking straight

International Nuclear Information System (INIS)

Anon

2000-01-01

A keynote speaker at Outlook 2001 conference, Robert Priddle, Executive Director of the International Energy Agency, provided a realistic assessment of the opportunities for a change in the energy supply mix in the light of the growing international debate about the design of a sustainable energy future. World energy supply today is based firmly on fossil fuels. Furthermore, projections of future supply, such as that made in the reference case of the recent World Energy Outlook by the IEA, indicate little change. Yet government's remain deeply engaged in efforts to reshape energy markets including (despite the failure of COP-6 in The Hague last November) efforts to curb national emissions of greenhouse gases, in particular from the energy sector. Australia has made considerable progress in developing and applying life cycle analysis to the energy sector. This effort demonstrates opportunities to combine, for example, coal seam methane capture, coal and biomass co-combustion, coal power generation and steel production and thus to reduce emissions by up to 15%. The prospect is that even with effective carbon constraints reflected in fuel prices, coal can remain a competitive fuel choice for longer than many analysts imagine. The outcome does not rely on exotic technology development, rather it requires the necessary market signals to create new business partnerships

Comparative life cycle assessment (LCA) of construction and demolition (C&D) derived biomass and U.S. northeast forest residuals gasification for electricity production.

Science.gov (United States)

Nuss, Philip; Gardner, Kevin H; Jambeck, Jenna R

2013-04-02

With the goal to move society toward less reliance on fossil fuels and the mitigation of climate change, there is increasing interest and investment in the bioenergy sector. However, current bioenergy growth patterns may, in the long term, only be met through an expansion of global arable land at the expense of natural ecosystems and in competition with the food sector. Increasing thermal energy recovery from solid waste reduces dependence on fossil- and biobased energy production while enhancing landfill diversion. Using inventory data from pilot processes, this work assesses the cradle-to-gate environmental burdens of plasma gasification as a route capable of transforming construction and demolition (C&D) derived biomass (CDDB) and forest residues into electricity. Results indicate that the environmental burdens associated with CDDB and forest residue gasification may be similar to conventional electricity generation. Land occupation is lowest when CDDB is used. Environmental impacts are to a large extent due to coal cogasified, coke used as gasifier bed material, and fuel oil cocombusted in the steam boiler. However, uncertainties associated with preliminary system designs may be large, particularly the heat loss associated with pilot scale data resulting in overall low efficiencies of energy conversion to electricity; a sensitivity analysis assesses these uncertainties in further detail.

Process analysis of an oxygen lean oxy-fuel power plant with co-production of synthesis gas

International Nuclear Information System (INIS)

Normann, Fredrik; Thunman, Henrik; Johnsson, Filip

2009-01-01

This paper investigates new possibilities and synergy effects for an oxy-fuel fired polygeneration scheme (transportation fuel and electricity) with carbon capture and co-firing of biomass. The proposed process has the potential to make the oxy-fuel process more effective through a sub-stoichiometric combustion in-between normal combustion and gasification, which lowers the need for oxygen within the process. The sub-stoichiometric combustion yields production of synthesis gas, which is utilised in an integrated synthesis to dimethyl ether (DME). The process is kept CO 2 neutral through co-combustion of biomass in the process. The proposed scheme is simulated with a computer model with a previous study of an oxy-fuel power plant as a reference process. The degree of sub-stoichiometric combustion, or amount of synthesis gas produced, is optimised with respect to the overall efficiency. The maximal efficiency was found at a stoichiometric ratio just below 0.6 with the efficiency for the electricity producing oxy-fuel process of 0.35 and a DME process efficiency of 0.63. It can be concluded that the proposed oxygen lean combustion process constitutes a way to improve the oxy-fuel carbon capture processes with an efficient production of DME in a polygeneration process

The estimated additional costs for combustion of agro fuel and the potential of farmers to influence fuel quality; Identifiering av energiverkens merkostnader vid foerbraenning av aakerbraenslen samt lantbrukarens moejlighet att paaverka braenslekvaliteten

Energy Technology Data Exchange (ETDEWEB)

Myringer, Aase; Petersen, Martin; Olsson, Johanna; Roennbaeck, Marie; Bubholz, Monika; Forsberg, Maya

2009-05-15

for each fuel and type of boiler, but the specific conditions prevailing in any individual plant will obviously affect the actual costs. General conclusions were: Additional costs for an outage caused by the agro fuel depend on whether there is an accumulator to cover some of the load, and on the other types of boilers and equipment available. Additional costs for ash handling depend on the technical system and business agreements concerning ash handling, which differed between the energy plants visited. Additional costs arising when a boiler and/or fuel is new can be reduced by hard work and experience. In one example (Saatenaes), feeding a new boiler with new straw with a moisture content of 20-22% caused problems with fuel feeding, more frequent soot blowing, etc. Through persistent efforts and feedback on straw quality to farmers, these problems have been eliminated. In two cases, 100% agro fuel was combusted during part load periods. In one case full load could not be achieved because of low bulk density and resulting limitations of the feeding system, and in the other case high load was known to cause problems with fouling and dust production. Using agro fuels during part load was not considered an additional cost. At the two combined heat and power plants (CHP-plants) visited, the upper limit for willow in the fuel mix was set at 15%, since additional costs caused by increased fouling are expected beyond this level (based on experience). This study has mainly focused on the cost for a plant to change from forestry fuels to agro fuels. However, a more common issue is to co-combust a cheaper fuel. This is especially true for larger boilers mainly due to the fact that the fuel availability is more uncertain if large quantities of agro fuels shall be used, and that problems like increased deposit or corrosion rate shall be avoided. Therefore this investigation has looked both at cases with combustion of 100 % agro crops (Jordbro, Kvaenum, Graestorp and Saatenaes

Experimental investigation of ash deposits characteristics of co-combustion of coal and rice hull using a digital image technique

International Nuclear Information System (INIS)

Qiu, Kunzan; Zhang, Hailong; Zhou, Hao; Zhou, Bin; Li, Letian; Cen, Kefa

2014-01-01

This paper investigated the ash deposit characteristics during the co-firing Da Tong (DA) coal with different proportions of rice hull (0%, 5%, 10%, and 20%, based on weight) in a pilot-scale furnace. The growth of ash deposit with a four-stage mode was presented. The stable thickness values of DA coal, 5% rice hull, 10% rice hull, and 20% rice hull were 0.5, 1.4, 2.9, 5.7 cm, with stable heat flux values of 230, 200, 175, and 125 kW/m 2 , respectively. According to the results of scanning electron microscopy with energy dispersive X-ray analysis (SEM-EDX), the amount of Si in the deposits increased with the increasing proportion of rice hull rich in SiO 2 . The X-ray diffraction (XRD) analysis results indicated that most elements except Si were in the amorphous state because of the formation of eutectics. The stable thicknesses of deposits increased exponentially with the proportion of rice hull. The deposit was loose, easy removable but it reduced the heat transfer significantly. Consequently, sootblowing timely was necessary when co-firing DA coal with rice hull. - Highlights: • Digital image technique was used to monitor deposits growth process. • A type of four stages mode of ash deposit growth was presented. • The heat flux of ash deposits fit a three-stage mode. • The addition of rice hull increased the porosity of deposits

CFD modeling of ash deposition for co-combustion of MBM with coal in a tangentially fired utility boiler

NARCIS (Netherlands)

Taha, T.J.; Stam, A.F.; Stam, K.; Brem, Gerrit

2013-01-01

Ash deposition is one of the main challenges that needs to be tackled in response to increased percentage of biomass co-firing in pulverized fuel boilers. In this study, a model has been developed to investigate the slagging behavior of meat and bone meal (MBM) at higher co-firing rates in the

Organic emissions from co-combustion of RDF with wood chips and milled peat in a bubbling fluidized bed boiler

International Nuclear Information System (INIS)

Vesterinen, Raili; Flyktman, Martti

1996-01-01

Refuse derived fuel (RDF) has been burned with wood chips and milled peat in a 4 MW bubbling fluidized bed boiler. Emissions of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/F) in flue gases expressed as TCDD-equivalents were significantly below the emission limit 0.1 ng/m 3 n I-TEQ (11 % O 2 ). Also the PCDD/F-concentrations of fly ashes separated by an electrostatic precipitator are significantly below the 1 ng/g I-TEQ limit for agricultural soil in Germany. The carbon monoxide content was rather high, but typical for many small district heating plants. The concentrations of other chlorinated aromatic compounds were also low, in some tests below the detection limit. The concentrations of polyaromatic hydrocarbons (PAH) were rather high. The leachable metal content of the fly ash generated were analyzed using U.S. EPA TCLP test (Toxicity Characteristic Leaching Procedure). All concentrations fell below boundary levels. (author)

Fly ashes from co-combustion as a filler material in concrete production; Anvaendning av energiaskor som fillermaterial vid betongtillverkning

Energy Technology Data Exchange (ETDEWEB)

Sundblom, Hillevi

2004-01-01

The Swedish concrete producers have decided to work towards a common goal to limit the production of concrete with naturally rounded aggregate. A consequence is when use of a substitute, crushed aggregate, the demand of filler material increases. During the last years ashes form the CFB boiler in Perstorp has been utilised as a filler material, with success, in concrete production at Sydsten, Malmoe, Sweden. To examine the potential of using Swedish fly ashes as a filler material in concrete production, have different Swedish fly ashes above been studied to see if they fit the requirements for a filler material. The fly ashes studied in the project can be divided into four different groups, considering fuel mix and boiler type; 1. Bio and sludge fired CFB/BFB boiler from the paper industry, 2. Bio and peat fired CFB/BFB boiler, 3. Pulverized peat/coal firing furnace, 4.Bio and peat fired grate-fired boiler. From Sydsten experiences of using Swedish fly ashes two demands have emerged concerning the chemical composition of the ashes. The total amount of chloride in the concrete should not be higher than 0,1% and the LOI, (Loss Of Ignition) must be less than 10 %. The different ash analyses showed that the fluidised bed boilers and pulverized firing furnaces, in this study, passed all the chemical requirements but the grate fire boilers had difficulties to fulfil the requirement of LOI. The ashes chosen to be studied in further rheological investigations in different fresh concrete mixtures were, Category 1 (Hallstavik's and Hyltebruk's papermill), Category 2 (Vaesteraas Vaermeverk och Vaertaverket) and from Category 3 (Vattenfall Vaerme Uppsala). The results presented an increased water consumption of ashes from paper mills comparing with the other ashes, a probable reason could be the shape of the ash grains. The experiments also showed that all ashes contributed to the final strength of the hardened concrete, the paper mill ashes also contributed to the initial strength development. During mixture of the fresh concrete with an ash quantity of 60 kg/m{sup 3}, it different degrees of loss of consistency was observed during the first hour after mixing. When decreasing the amount of ash to 30 kg/km{sup 3}, it was only the paper mill ashes that could not maintain the consistency during the first hour. The mechanisms that are dominating in the interaction between ash and cement during the hardening of the fresh concrete are complex. The reasons why certain ashes create a greater loss of consistency than others are not fully understood. It is necessary to continue research in this issue for simplifying the choices when using ashes in different concrete application. This project resulted in full-scale demonstration. Sydsten in Malmoe delivered concrete with ash from the pulverized peat-firing furnace in Uppsala as a filler material to a concrete casting in Lund. The concreting was very successful. The concrete did not loose the consistency as noted in the laboratory experiments. The concrete also demonstrated an excellent workability. The overall conclusion is, some of the Swedish fly ashes are very suitable to use as a filler material in concrete. A full-scale demonstration and delivery to customer has already been made in south of Sweden (Sydsten). There is also potential to find methods to refine ashes, which today don't fulfil the requirements of consistency for example sieving, to reduce the quantity of LOI.

[Combustion zone investigation and modelling in fuel flexible suspension fired boilers]. Result summary and status

Energy Technology Data Exchange (ETDEWEB)

Lovmand Hvid, S.

2011-12-15

The project has been designed to obtain data from a power plant boiler with co-combustion, partly to gain greater knowledge of particle turnover in the fuel zone, partly to support the development of modeling tools. Data collection occurred at Studstrup Power Station Unit 4, where the fuel is a combination of coal and biomass. The boiler is equipped with 24 dust burners, four of which have been converted to firing with biomass. Measurements have been carried out in the flame zone with different fuels: coal alone, coal + straw and coal + wood. During the experiments velocity fields, temperature fields and gas concentration fields were measured in the firing zone. Also, particle samples from the flame zone ware collected. Several measurements are performed with well-known techniques, but in addition, the project developed new optical measurement methods based on UV spectroscopy. They allow measuring other gases than the hitherto known methods and allow you to gain insight into the dynamic variations beyond just mean fields. The collection of particle samples from the boiler was, as expected, a very challenging task under the given conditions, but was carried out with a largely satisfactory result. Analysis of the samples has initially failed to lead to an increased recognition of the speed of the conversion process, but the samples will be analyzed in more detail in other projects. (LN)

Biophysical studies related to energy generation: Progress report

International Nuclear Information System (INIS)

Green, A.E.S.

1988-01-01

This report covers work subsequent to our previous report of December 24, 1986. At that time we were groping to find relationships between vibrational and rotational electron impact cross sections in the vapor and liquid phases of water. Having reached an impass within the radiological literature, we drew upon the atmospheric, oceanographic and flame radiation literatures. Here a much broader body of excitation energy and intensity data related to the vibrational and rotational excitation of water in the vapor phases and liquid phases enabled us to identify certain ''big bands'' of H 2 O. These bands account for the major infrared absorption features observed in atmospheric transmission studies as well as important spectral radiation features observed in hydrocarbon combustion. Related liquid phase-gas phase involvement also entered our work on co-combustion of biomass and waste, and natural gas in studies directed toward contributing to the solution of national energy-environmental and economic problems. Attachments to this report include our published works, submitted works, and in complete studies related to radiological, atmospheric, and combustion studies which encompass biophysical studies related to energy generation and which have a common thread involving water in liquid and vapor form. These works are tied together in this brief report, along with some comments on trends in science and technology which they might illustrate

Thermogravimetric analysis of anthracite and waste plastics by iso-conversional method

International Nuclear Information System (INIS)

Ren, Shan; Zhang, Jianliang

2013-01-01

Highlights: • Co-combustion kinetic analysis of solid fuels was made by iso-conversional method. • Thermodynamic and kinetic parameters of combustion for blends were determined. • WP can improve the combustion characteristic of high ash anthracite. • Reasonable utilization the energy of WP is important for industrial production. - Abstract: Combustion mechanisms and kinetics of plastics-coal blends with 0, 10, 20, 40 and 100% waste plastics (WP) are studied separately by thermogravimetric analysis (TGA) from ambient temperature to 900 °C in air atmosphere. These blends are combusted at different heating rates. The results indicate that, with the increase of waste plastics content, the combustion processes of blends could be divided into one stage, two stages, three stages and one stage. Meanwhile, the ignition and final temperatures of them both decrease. The maximum weight loss rate of WP is much higher than that of other samples. The iso-conversional method is used for the kinetic analysis of the non-isothermal thermogravimetric data and results indicate that, when the waste plastics content varied from 0% to 40%, the values of activation energy increase from 113.3 kJ mol −1 to 156.0 kJ mol −1 , and the value of activation energy for pure WP is 278.8 kJ mol −1

Process-related aspects to the co-combustion of wastes in rotary kilns; Verfahrenstechnische Gesichtspunkte zur Mitverbrennung von Abfaellen in Drehrohroefen

Energy Technology Data Exchange (ETDEWEB)

Endres, G. [Pillard Feuerungen GmbH, Taunusstein (Germany)

1998-09-01

Apart from large quantities of energy, the cement industry also depends for the manufacture of its product on certain raw materials such as limestone, marl, alum earth etc. which are typically produced by open pit mining. As a consequence, cement works in the course of time become surrounded with holes of different depth in the Earth`s surface which are later used for the disposal of household waste. Interestingly, the chemical composition of this household waste is not substantially different from that of the raw materials initially extracted from the Earth for the purpose of cement manufacture. Moreover, in contravention of medium-term trends in legislation on surface landfilling this dumped waste contains chemically bound energy. What could be more obvious, therefore, than to consider using household waste as a raw material and energy source for cement burning? [Deutsch] Die Zementindustrie benoetigt zur Herstellung ihres verkaufsfaehigen Produkts neben grossen Mengen von thermischer Energie insbesondere Rohstoffe wie Kalkstein, Mergel, Tonerde usw., die typischerweise im Tagebau gewonnen werden, es entstehen in der Nachbarschaft von Zementwerken also mehr oder weniger tiefe Loecher in der Erdoberflaeche, die in vielen Faellen bereits wieder zur Deponierung von Siedlungsabfaellen genutzt werden. Diese Siedlungsabfaelle unterscheiden sich in der chemischen Zusammenarbeit ihrer Asche interessanterweise nicht sehr von den Rohstoffen, die fuer die Zementproduktion aus der Erde gegraben werden, desweiteren enthalten sie chemisch gebundene Waermeenergie, was gemaess der mittelfristigen Gesetzeslage einer oberirdischen Deponierung eigentlich entgegensteht. Was liegt also naeher, als ueber eine Nutzung dieser Abfaelle als Rohstoff und Energietraeger im Zementbrennprozess nachzudenken? (orig.)

Research on use of bioenergy; Bioenergian kaeyttoe. Tutkimusalueen katsaus

Energy Technology Data Exchange (ETDEWEB)

Helynen, S [VTT Energy, Jyvaeskylae (Finland)

1997-12-01

The aims of Bioenergy Research Programme have been achieved in the field of fuel handling technologies and small scale combustion concepts but 3 - 4 large scale demonstration projects (0,2 - 0,3 million toe/year per utilization concept) before the year 2000 seems to be a very challenging aim. Ignition and explosion properties of wood and agro biomasses and biomass-coal mixtures are determined in atmospheric and pressurized conditions by VTT Energy with Spanish, French, Dutch and German partners in JOULE-project. Explosion suppression systems have also been tested successfully in pressurized conditions up to 10 bar with British partners. Feasibility of reed canary grass for chemical pulp and fuel is evaluated in a large FAIR project. VTT Energy is responsible for pelletising of fuel fraction, combustion of pellets, gasification and combustion of pulverized fuel fraction. Development of a system for receiving, crushing and screening recycled fuel material was concentrated on a heavy-duty two-rotor crusher and a crushing screen by BMH Wood Technology. Primary and secondary crushing are needed for optimum particle size distribution. The system will be demonstrated in Sweden. Dry gas-cleaning methods for gasification-diesel power plants and for other atmospheric-pressure applications of biomass gasification are developed by VTT Energy. Catalytic gas-cleaning methods are tested for engine applications in PDU-scale. Removal of trace metals, chlorine and other harmful contaminants of CFB gasification is studied with regard to co-combustion of the product gas in PC boilers

Air pollution reduction with respect to the conversion of biomass into electricity and heat. Emission and cost indexes

International Nuclear Information System (INIS)

Bergsma, G.C.; Croezen, H.C.; De Weerd, G.; Van der Werff, T.

1999-01-01

Although biomass conversion is considered to be a CO2-free method of producing electricity and heat other emissions have to be taken into account: SO2, NOx, HCl, HF, Hg, Cd, dusts, etc. The aim of the study on the title subject is to support the Dutch Ministry of Housing, Planning and Environment (VROM) in the determination of feasible emission standards for bioconversion installations. The Centre for Energy conservation and clean technology (CE) compiled information on the costs for flue gas purification for different degrees of purification. Because of the fact that the composition of flue gases strongly depends on the biomass flow and the applied conversion technique, both biomass flows and conversion techniques must be distinguished. The following biomass conversion techniques were studied: large-scale combustion of wood wastes and sludges, large-scale gasification of wood wastes, cocombustion of wood wastes and sludges, small-scale combustion of wood wastes and chicken manure, small-scale gasification of wood wastes, and fermentation of wastes from vegetables, fruits and gardens. For each combination it is determined what the emissions are in case of a minimal flue gas purification, what the emissions are and how much additional costs are involved in case the regulations in the BLA (decree on air pollution of waste incineration) are taken into account, and what the emissions are and how much additional costs are involved for a number of levels in between the two fore-mentioned cases. refs

Decreased PCDD/F formation when co-firing a waste fuel and biomass in a CFB boiler by addition of sulphates or municipal sewage sludge.

Science.gov (United States)

Åmand, Lars-Erik; Kassman, Håkan

2013-08-01

Polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs) are formed during waste incineration and in waste-to-energy boilers. Incomplete combustion, too short residence times at low combustion temperatures (boilers. The impact of chlorine and catalysing metals (such as copper and iron) in the fuel on PCDD/F formation was studied in a 12 MW(th) circulating fluidised bed (CFB) boiler. The PCDD/F concentrations in the raw gas after the convection pass of the boiler and in the fly ashes were compared. The fuel types were a so-called clean biomass with low content of chlorine, biomass with enhanced content of chlorine from supply of PVC, and solid recovered fuel (SRF) which is a waste fuel containing higher concentrations of both chlorine, and catalysing metals. The PCDD/F formation increased for the biomass with enhanced chlorine content and it was significantly reduced in the raw gas as well as in the fly ashes by injection of ammonium sulphate. A link, the alkali chloride track, is demonstrated between the level of alkali chlorides in the gas phase, the chlorine content in the deposits in the convection pass and finally the PCDD/F formation. The formation of PCDD/Fs was also significantly reduced during co-combustion of SRF with municipal sewage sludge (MSS) compared to when SRF was fired without MSS as additional fuel. Copyright © 2013 Elsevier Ltd. All rights reserved.

Multi-criteria decision-making in the selection of a renewable energy project in spain: The Vikor method

International Nuclear Information System (INIS)

San Cristobal, J.R.

2011-01-01

One of the characteristics of the Spanish energy system is its high degree of dependence on imports. In 2005, the Spanish government approved the new Renewable Energy Plan in the following sectors: Windpower, Hydroelectric, Solar Thermal, Solar Thermo-electric, Photovoltaic, Biomass, Biogas and Biofuels. The aim of the Plan is to make it possible to reach the target of 12% of primary energy being met from renewable sources by 2010. When selecting one from various Renewable Energy investment projects different groups of decision-makers become involved in the process. Decision-making has to take into consideration several conflicting objectives because of the increasingly complex social, economic, technological, and environmental factors that are present. Traditional single-criterion decision-making is no longer able to handle these problems. The Compromise Ranking method, also known as the VIKOR method, introduces the Multi-criteria ranking index based on the particular measure of ''closeness'' to the ''ideal'' solution. In this paper, we apply the method in the selection of a Renewable Energy project corresponding to the Renewable Energy Plan launched by the Spanish Government. The method is combined with the Analytical Hierarchy Process method for weighting the importance of the different criteria, which allows decision-makers to assign these values based on their preferences. The results show that the Biomass plant option (Co-combustion in a conventional power plant) is the best choice, followed by the Wind power and Solar Thermo-electric alternatives. (author)

Mechanisms and kinetics of granulated sewage sludge combustion.

Science.gov (United States)

Kijo-Kleczkowska, Agnieszka; Środa, Katarzyna; Kosowska-Golachowska, Monika; Musiał, Tomasz; Wolski, Krzysztof

2015-12-01

This paper investigates sewage sludge disposal methods with particular emphasis on combustion as the priority disposal method. Sewage sludge incineration is an attractive option because it minimizes odour, significantly reduces the volume of the starting material and thermally destroys organic and toxic components of the off pads. Additionally, it is possible that ashes could be used. Currently, as many as 11 plants use sewage sludge as fuel in Poland; thus, this technology must be further developed in Poland while considering the benefits of co-combustion with other fuels. This paper presents the results of experimental studies aimed at determining the mechanisms (defining the fuel combustion region by studying the effects of process parameters, including the size of the fuel sample, temperature in the combustion chamber and air velocity, on combustion) and kinetics (measurement of fuel temperature and mass changes) of fuel combustion in an air stream under different thermal conditions and flow rates. The combustion of the sludge samples during air flow between temperatures of 800 and 900°C is a kinetic-diffusion process. This process determines the sample size, temperature of its environment, and air velocity. The adopted process parameters, the time and ignition temperature of the fuel by volatiles, combustion time of the volatiles, time to reach the maximum temperature of the fuel surface, maximum temperature of the fuel surface, char combustion time, and the total process time, had significant impacts. Copyright © 2015 Elsevier Ltd. All rights reserved.

A blocked takeover in the Polish power sector: A model-based analysis

International Nuclear Information System (INIS)

Kamiński, Jacek

2014-01-01

As the President of the Office of Competition and Consumer Protection refused to approve a government initiated takeover in the Polish power sector and the Court of Competition and Consumer Protection did not make a ruling on that case, the takeover was finally prohibited. In this context, the main aim of this paper is to carry out a quantitative analysis of the impact of the takeover in question on electricity prices and quantities, consumer and producer surpluses, dead weight loss and emissions. The scope of the study covers the Polish power generation sector and the analysis was carried out for 2009. A game theory-based electricity market equilibrium model developed for Poland was applied. The model includes several country-specific conditions, such as a coal-based power generation fuel-mix, a large share of biomass co-combustion, etc. For the sake of clarity, only four scenarios are assumed. The paper concludes that the declared synergy savings did not compensate for the increase in dead weight loss and the transfer of surplus from consumers to producers caused by increased market power. - Highlights: • A takeover blocked by the President of the Office of Competition and Consumer Protection was analysed. • A game theory-based model of the Polish wholesale electricity market was applied. • The impact of the takeover on electricity prices and generation levels, surplus transfers and dead weight loss was estimated. • The results were compared with the declared synergy savings

Eco-balance of sewage sludge disposal: Agricultural uses, monocombustion or co-combustion; Oekobilanz der Klaerschlammentsorgung: Landwirtschaftliche Verwertung, Mono- oder Co-Verbrennung

Energy Technology Data Exchange (ETDEWEB)

Fehrenbach, H. [ifeu-Institut fuer Energie- und Umweltforschung GmbH, Heidelberg (Germany)

2001-07-01

fhe German state of Nordrhein-Westfalen envisages a state-wide strategy for sewage sludge utilization. The ifeu-Institute, Heidelberg, was commissioned to provide the planning fundamentals. About 530,000 t of dried sewage sludge are produced in NRW every year. Utilization concepts included the use as an agricultural fertilizer, in landscaping, and several variants of incineration. The methodology and results are presented here. [German] Das Land Nordrhein-Westfalen strebt eine landesweite Abfallwirtschaftsplanung fuer Klaerschlamm an, die sich an den genannten Grundsaetzen orientieren soll. Das ifeu-Institut, Heidelberg, wurde vom Ministerium fuer Umwelt und Naturschutz, Landwirtschaft und Verbraucherschutz (MUNLV) beauftragt, die abfallwirtschaftlichen und oekobilanziellen Grundlagen fuer die Planung zu erstellen. Fuer die Entsorgung des in NRW mit 530.000 t Trockenmasse im Jahr anfallenden Klaerschlamms wurden dabei die Verwertung in der Landwirtschaft, der Einsatz im Landschaftsbau und die Verbrennung, mit jeweils allen wesentlichen in NRW realisierten technischen Varianten bewertet. Die Vorgehensweise sowie die wesentlichen Ergebnisse der oekobilanziellen Bewertung der Optionen der Klaerschlammentsorgung werden hier zusammengefasst. (orig.)

Reduced ash-related operational problems by co-combustion peat and agricultural fuels; Minskade askrelaterade driftsproblem genom inblandning av torv i aakerbraenslen

Energy Technology Data Exchange (ETDEWEB)

Oehman, Marcus; Bostroem, Dan; Skoglund, Nils; Grimm, Alejandro; Boman, Christoffer; Kofod-Hansen, Marie

2010-06-15

The objectives of the project were: To determine the admixing levels for different peat classes to various energy crops (straw, Salix and Reed canary grass) that are required to reach positive effects regarding slagging, deposit formation/(high temperature corrosion) and bed agglomeration; and, To demonstrate the possibilities to reduce the occurrence of ash related operational problems in combustion of energy crops upon admixing peat. Operational experiences and research of effects of co-firing peat and energy crops are scarce. Some previous tests in bench scale indicated though, on a strong reduction of the agglomeration tendency and lowering of the agglomeration temperature for straw and Salix at a peat admixing level corresponding to 15 - 20 weight% (on DS basis). A reduction in the amount of emitted fine particles was also observed in these experiments. However, care must be taken in the choice of peat. Some Carex dominated peats with high Si contents may cause problems with slagging. Another conclusion from the mentioned bench scale tests was that peats with relative high Ca/Si ratios should be selected to minimize the risk of slagging and bed agglomeration. Thermochemical modelling was performed to determine the effects of peat admixture, on slagging-, deposit formation- (corrosion)- and bed agglomeration tendencies during combustion of straw, willow and reed canary grass with high and low ash content. These results and previously conducted bench scale experiments were used as a basis for determining combinations of fuel and peat admixtures for the demonstration experiments. The calculations were performed with admixing levels of 0-, 5-, 15, 25-, and 40 weight% (on DS basis) of four peat samples to the investigated four crop fuels. The used peat samples were typical carex-containing Swedish peat with differences in e.g. silicon-, calcium- and sulfur contents. A number of the model calculations were qualitatively validated against previously conducted controlled combustion experiments in bench scale (grate/fluidized bed). Good agreement between the theoretical and practical results on critical ash-chemical sub-processes was observed. Combustion tests were carried out during approximately 2 days in a 4 MW grate fired boiler, using; - briquetted reed canary grass (RCG) fuel with high ash content (totally 25 ton DS). - a RCG with low ash content, co-briquetted with peat (85/15 % on DS basis, totally 25 tons). - Salix chips (approx. 40 tons). - Salix chips admixed with peat (15% on DS basis, totally approx. 40 tons). The overall conclusions of the model calculations concerning the ash content of a 'good peat' was that high ash content, high Si content, high S content and high Ca/Si ratio were favourable. Therefore the peat that mostly corresponded to these requirements was chosen for the demonstration tests. Combustion tests were also performed in a 20 kW underfed pellets burner attached to a pellets boiler. Pelletized straw (50 kg) and straw co-pelletized with peat (60/40% on DS basis, totally 50 kg), were used as fuel. The results shows that admixing a typical carex based peat into Salix and Reed canary grass with low ash content gives positive effects concerning both bed agglomeration and deposit formation (corrosion) in the convection parts of the boiler, already at low levels (15 weight% on DS basis). A carex based peat with a relative high Ca/Si ratio is recommended for co-firing with Salix in grate fired boilers, to avoid slagging. The same type of peat should also be utilized in co-firing Reed canary grass with low ash content (relative low admixing levels is sufficient) and wheat straw (high levels are required) to reduce the risk of slagging. In the choice of peat, a general recommendation can be made that peat with high ash content (carex based peat), preferably with high S content and a high Ca/Si ratio (a wt-ratio around 1 is desirable). Reed canary grass with high ash content is not expected to cause any substantial operational problems such as deposit formation and slagging/ bed agglomeration. Thus, from an operational perspective there is no need to apply co-firing this fuel with peat. To significantly reduce the fine particulate emission/deposit formation tendency in straw combustion with peat co-firing, would require such high levels of admixture that it not is interesting in the practice

Limits to co-combustion of coal and eucalyptus due to water availability in the state of Rio Grande do Sul, Brazil

International Nuclear Information System (INIS)

Hoffmann, Bettina Susanne; Szklo, Alexandre; Schaeffer, Roberto

2014-01-01

Highlights: • Brazil holds reserves of high ash coal that can only be used in mine-mouth plants. • Water scarcity requires the use of wet or dry cooling systems in several regions. • The co-firing of 30 wt% eucalyptus is possible regarding the biomass availability. • Biomass cultivation would aggravate the water scarcity in several regions. - Abstract: Brazil has favorable edaphoclimatic conditions for the cultivation of biomass for energy. On the other hand, the country plans to expand its thermal power park using fossil fuels, including Brazil’s high ash coal. This study estimates the potential of co-firing biomass from energy forests in power plants fired with Brazilian coal in the state of Rio Grande do Sul, Brazil, focusing on the limits given by biomass and water availability. Results show that the state holds coal reserves that could support a potential of approximately 8 GW. Referring to limits due to water availability, different outcomes were found for the various coal fields in Rio Grande do Sul. The Candiota coal field, which represents the most important coal field, holding a capacity of 4 GW, shows severe restrictions for water availability that would be aggravated by intense eucalyptus cultivation

Long-term affected energy production of waste to energy technologies identified by use of energy system analysis.

Science.gov (United States)

Münster, M; Meibom, P

2010-12-01

Affected energy production is often decisive for the outcome of consequential life-cycle assessments when comparing the potential environmental impact of products or services. Affected energy production is however difficult to determine. In this article the future long-term affected energy production is identified by use of energy system analysis. The focus is on different uses of waste for energy production. The Waste-to-Energy technologies analysed include co-combustion of coal and waste, anaerobic digestion and thermal gasification. The analysis is based on optimization of both investments and production of electricity, district heating and bio-fuel in a future possible energy system in 2025 in the countries of the Northern European electricity market (Denmark, Norway, Sweden, Finland and Germany). Scenarios with different CO(2) quota costs are analysed. It is demonstrated that the waste incineration continues to treat the largest amount of waste. Investments in new waste incineration capacity may, however, be superseded by investments in new Waste-to-Energy technologies, particularly those utilising sorted fractions such as organic waste and refuse derived fuel. The changed use of waste proves to always affect a combination of technologies. What is affected varies among the different Waste-to-Energy technologies and is furthermore dependent on the CO(2) quota costs and on the geographical scope. The necessity for investments in flexibility measures varies with the different technologies such as storage of heat and waste as well as expansion of district heating networks. Finally, inflexible technologies such as nuclear power plants are shown to be affected. Copyright © 2010 Elsevier Ltd. All rights reserved.

Ecological assessment of integrated bioenergy systems using the Sustainable Process Index

International Nuclear Information System (INIS)

Krotscheck, C.; Konig, F.; Obernberger, I.

2000-01-01

Biomass utilisation for energy production presently faces an uphill battle against fossil fuels. The use of biomass must offer additional benefits to compensate for higher prices: on the basis of a life cycle assessment (using BEAM to evaluate a variety of integrated bioenergy systems in connection with the Sustainable Process Index as a highly aggregated environmental pressure index) it is shown that integrated bioenergy systems are superior to fossil fuel systems in terms of environmental compatibility. The implementation of sustainability measures provides additional valuable information that might help in constructing and optimising integrated bioenergy systems. For a set of reference processes, among them fast pyrolysis, atmospheric gasification, integrated gasification combined cycle (IGCC), combustion and steam cycle (CS) and conventional hydrolysis, a detailed impact assessment is shown. Sensitivity analyses of the most important ecological parameters are calculated, giving an overview of the impacts of various stages in the total life cycle and showing 'what really matters'. Much of the ecological impact of integrated bioenergy systems is induced by feedstock production. It is mainly the use of fossil fuels in cultivation, harvesting and transportation as well as the use of fertilisers in short-rotation coppice production that impose considerable ecological pressure. Concerning electricity generation the most problematic pressures are due to gaseous emissions, most notably the release of NO x . Moreover, a rather complicated process (high amount of grey energy) and the use of fossil pilot fuel (co-combustion) leads to a rather weak ecological performance in contrast to other 100% biomass-based systems. (author)

FINE PARTICAL AND TOXIC METAL EMISSIONS FROM THE COMBUSTION OF SEWAGE SLUDGE/COAL MIXTURES: A SYSTEMATIC ASSESSMENT

Energy Technology Data Exchange (ETDEWEB)

Jost O.L. Wendt; Wayne S. Seames; Art Fernandez

2003-09-21

This research project focuses on pollutants from the combustion of mixtures of dried municipal sewage sludge (MSS) and pulverized coal. The objective was to determine potential tradeoffs between CO{sub 2} mitigation through using a CO{sub 2} neutral fuel, such as municipal sewage sludge, and the emergence of other potential problems such as the emission of toxic fly ash particles. The work led to new insight into mechanisms governing the partitioning of major and trace metals from the combustion of sewage sludge, and mixtures of coal and sewage sludge. The research also showed that the co-combustion of coal and sewage sludge emitted fine particulate matter that might potentially cause greater lung injury than that from the combustion of either coal alone or municipal sewage sludge alone. The reason appeared to be that the toxicity measured required the presence of large amounts of both zinc and sulfur in particles that were inhaled. MSS provided the zinc while coal provided the sulfur. Additional research showed that the toxic effects could most likely be engineered out of the process, through the introduction of kaolinite sorbent downstream of the combustion zone, or removing the sulfur from the fuel. These results are consequences of applying ''Health Effects Engineering'' to this issue. Health Effects Engineering is a new discipline arising out of this work, and is derived from using a collaboration of combustion engineers and toxicologists to mitigate the potentially bad health effects from combustion of this biomass fuel.

Sewage sludge as a fuel and raw material for phosphorus recovery: Combined process of gasification and P extraction.

Science.gov (United States)

Gorazda, K; Tarko, B; Werle, S; Wzorek, Z

2018-03-01

Increasing problems associated with sewage sludge disposal are observed nowadays. As the thermal conversion of sewage sludge (combustion, co-combustion, gasification and pyrolysis) appears to be the most promising alternative for its management, the solid residues left after gasification were examined. The present study evaluates the potential of this waste as an alternative phosphorus source in the context of phosphorus recovery. The obtained solid gasification residues were characterised (chemical and phase composition, thermal properties, surface properties and technological parameters used for phosphorus raw materials) and compared to commercial phosphate raw materials. It was revealed that gasification residue is a valuable source of phosphorus and microelements, comparable to sewage sludge ash (SSA) considered nowadays as secondary phosphorus raw materials. Chemical properties as well as technological parameters characteristic for natural phosphate ores are different. Solid gasification residue was leached with mineral acids (phosphoric and nitric) according to the patented method of phosphorus recovery - PolFerAsh, developed by Cracow University of Technology. It was revealed that phosphorus can be selectively leached from solid gasification residue with high efficiency (73-82%); moreover, most of the iron and heavy metals stay in the solid phase due to the low concentration of acids and proper solid to liquid phase ratio. The obtained leachates are valuable products that can be considered for the production of fertilisers. Combining the gasification process with nutrient recovery provides the opportunity for more environmentally efficient technologies driven by sustainable development rules. Copyright © 2017 Elsevier Ltd. All rights reserved.

Determining the amount of waste plastics in the feed of Austrian waste-to-energy facilities.

Science.gov (United States)

Schwarzböck, Therese; Van Eygen, Emile; Rechberger, Helmut; Fellner, Johann

2017-02-01

Although thermal recovery of waste plastics is widely practiced in many European countries, reliable information on the amount of waste plastics in the feed of waste-to-energy plants is rare. In most cases the amount of plastics present in commingled waste, such as municipal solid waste, commercial, or industrial waste, is estimated based on a few waste sorting campaigns, which are of limited significance with regard to the characterisation of plastic flows. In the present study, an alternative approach, the so-called Balance Method, is used to determine the total amount of plastics thermally recovered in Austria's waste incineration facilities in 2014. The results indicate that the plastics content in the waste feed may vary considerably among different plants but also over time. Monthly averages determined range between 8 and 26 wt% of waste plastics. The study reveals an average waste plastics content in the feed of Austria's waste-to-energy plants of 16.5 wt%, which is considerably above findings from sorting campaigns conducted in Austria. In total, about 385 kt of waste plastics were thermally recovered in all Austrian waste-to-energy plants in 2014, which equals to 45 kg plastics cap -1 . In addition, the amount of plastics co-combusted in industrial plants yields a total thermal utilisation rate of 70 kg cap -1  a -1 for Austria. This is significantly above published rates, for example, in Germany reported rates for 2013 are in the range of only 40 kg of waste plastics combusted per capita.

Cleaning of biomass derived product gas for engine applications and for co-firing in PC-boilers

Energy Technology Data Exchange (ETDEWEB)

Kurkela, E; Staahlberg, P; Laatikainen-Luntama, J [VTT Energy, Espoo (Finland). Energy Production Technologies; and others

1997-10-01

The conventional fluidized-bed combustion has become commercially available also to relatively small scale (5 MWe), but this technology has rather low power-to-heat ratio and consequently it`s potential is limited to applications where district or process heat is the main product. Thus, there seems to be a real need to develop more efficient methods for small-scale power production from biomass. Gasification diesel power plant is one alternative for the small-scale power production, which has clearly higher power-to-heat ratio than can be reached in conventional steam cycles. The main technical problem in this process is the gas cleaning from condensable tars. In addition to the diesel-power plants, there are several other interesting applications for atmospheric-pressure clean gas technology. One alternative for cost-effective biomass utilization is co-firing of biomass derived product gas in existing pulverized coal fired boilers (or other types of boilers and furnaces). The aim of the project is to develop dry gas cleaning methods for gasification-diesel power plants and for other atmospheric-pressure applications of biomass and waste gasification. The technical objectives of the project are as follows: To develop and test catalytic gas cleaning methods for engine. To study the removal of problematic ash species of (CFE) gasification with regard to co-combustion of the product gas in PC boilers. To evaluate the technical and economical feasibility of different small-scale power plant concepts based on fixed-bed updraft and circulating fluidized- bed gasification of biomass and waste. (orig.)

Formation of chlorinated organic compounds in fluidized bed combustion of recycled fuels; Kloorattujen orgaanisten yhdisteiden muodostuminen kierraetyspolttoaineiden leijukerrospoltossa

Energy Technology Data Exchange (ETDEWEB)

Vesterinen, R.; Kallio, M.; Kirjalainen, T.; Kolsi, A.; Merta, M. [VTT Energy, Jyvaeskylae (Finland)

1997-10-01

Four tests of co-combustion of recycled fuels (REP) with peat and coal in the 15 kW fluidized bed reactor were performed. The recycled fuel was so-called dry fraction in four vessels sampling at Keltinmaeki. In three tests a part of peat energy was replaced with coal. The mixtures were prepared so that in all mixtures 25 % of energy was recycled fuel and 75 % was either peat or the mixture of peat and coal. The concentrations of polyaromatic hydrocarbons (PAH), polychlorinated dibenzo-p-dioxins (PCDDs) and dibenzofurans (PCDFs) and chlorophenols decreased with increasing part of coal due to the increasing sulphur/chlorine ratio. Principal Component Analysis (PCA) and Partial Least Square regression analysis (PLS) showed that the chlorine, copper and sulphur contents of the fuel effected most on the concentrations of chlorophenols, chlorobenzenes, PCBs and PCDDs/PCDFs. Other variables influencing on a model were the lead concentration and the sulphur/chlorine ratio in fuel and the hydrogen chloride concentration of the flue gas. The concentrations of chlorophenols and chlorobenzenes were also significant for PCDD/PCDF concentrations in flue gas. The sulphur, chlorine, copper and chromium contents in fly ash and the temperature of the reactor influenced on the chlorophenol, chlorobenzene, PCB and PCDD/PCDF concentrations in fly ash. The chlorophenol and chlorobenzene contents in fly ash, the sulphur/chlorine ratio and the lead content in fuel, the sulphur dioxide, hydrogen chloride and carbon monoxide concentrations in flue gas had also influence on PCDD/PCDF concentrations in fly ash

Formation of chlorinated organic compounds in fluidized bed combustion of recycled fuels

International Nuclear Information System (INIS)

Vesterinen, R.; Kallio, M.; Kirjalainen, T.; Kolsi, A.; Merta, M.

1997-01-01

Four tests of co-combustion of recycled fuels (REP) with peat and coal in the 15 kW fluidized bed reactor were performed. The recycled fuel was so-called dry fraction in four vessels sampling at Keltinmaeki. In three tests a part of peat energy was replaced with coal. The mixtures were prepared so that in all mixtures 25 % of energy was recycled fuel and 75 % was either peat or the mixture of peat and coal. The concentrations of polyaromatic hydrocarbons (PAH), polychlorinated dibenzo-p-dioxins (PCDDs) and dibenzofurans (PCDFs) and chlorophenols decreased with increasing part of coal due to the increasing sulphur/chlorine ratio. Principal Component Analysis (PCA) and Partial Least Square regression analysis (PLS) showed that the chlorine, copper and sulphur contents of the fuel effected most on the concentrations of chlorophenols, chlorobenzenes, PCBs and PCDDs/PCDFs. Other variables influencing on a model were the lead concentration and the sulphur/chlorine ratio in fuel and the hydrogen chloride concentration of the flue gas. The concentrations of chlorophenols and chlorobenzenes were also significant for PCDD/PCDF concentrations in flue gas. The sulphur, chlorine, copper and chromium contents in fly ash and the temperature of the reactor influenced on the chlorophenol, chlorobenzene, PCB and PCDD/PCDF concentrations in fly ash. The chlorophenol and chlorobenzene contents in fly ash, the sulphur/chlorine ratio and the lead content in fuel, the sulphur dioxide, hydrogen chloride and carbon monoxide concentrations in flue gas had also influence on PCDD/PCDF concentrations in fly ash

Artificial lightweight aggregates as utilization for future ashes - A case study.

Science.gov (United States)

Sarabèr, Angelo; Overhof, Robert; Green, Terry; Pels, Jan

2012-01-01

In the future, more electricity in the Netherlands will be produced using coal with co-combustion. Due to this, the generated annual ash volume will increase and the chemical composition will be influenced. One of the options for utilization if present markets are saturated and for use of fly ashes with different compositions, is as raw material for lightweight aggregates. This was selected as one of the best utilizations options regarding potential ash volume to be applied, environmental aspects and status of technology. Because of this, a study has been performed to assess the potential utilization of fly ash for the production of lightweight aggregate. Lightweight aggregate has been produced in a laboratory scale rotary kiln. The raw material consisted of class F fly ash with high free lime content. An addition of 8% clay was necessary to get green pellets with sufficient green strength. The basic properties of the produced lightweight aggregate and its behaviour in concrete have been investigated. The concrete has a good compressive strength and its leaching behaviour meets the most stringent requirements of Dutch environmental regulations. The carbon foot print of concrete will be negatively influenced if only the concrete itself is taken into account, but the reduction of the volume weight has advantages regarding design, transport emissions and isolation properties which may counteract this. In the Dutch situation the operational costs are higher than expected potential selling price for the LWA, which implies that the gate fee for the fly ash is negative. Copyright © 2011 Elsevier Ltd. All rights reserved.

Physico-chemical analysis and calorific values of poultry manure.

Science.gov (United States)

Quiroga, G; Castrillón, L; Fernández-Nava, Y; Marañón, E

2010-05-01

Spain is one of the major producers of broilers and laying hens in the European Union, with an overall market share of around 12%. The poultry manure that is produced is usually employed as fertilizer on cropland, either directly or after a composting process. In some cases, however, this waste is transported over 120km to be used as fertilizer, with the resulting high transport costs. In other countries, poultry manure is used as an alternative natural fuel source for power generation. In this study, poultry manure from all the laying hen farms in Asturias was characterized with a view to its possible use as an energy source. The Higher Heating Values on a dry basis (experimental) varies between 12,052 and 13,882kJ/kg. Lower Heating Values (LHVs) on a wet basis range are much lower (mean values of 2664kJ/kg) due to the high moisture content of poultry manure. Accordingly, the co-combustion of this waste with other types of waste such as forest and wood waste (LHV on a wet basis of 8044 and 15,830kJ/kg, respectively) or municipal solid waste (LHV on a wet basis of 10,725kJ/kg) should be considered as an alternative energy source. Chlorine and sulphur contents in dry matter vary around mean values of 0.64% and 0.11%, respectively. The waste also presents high amounts of Ca (4.84%) and K (2.38%). Copyright (c) 2010 Elsevier Ltd. All rights reserved.

Mathematical modeling of biomass fuels formation process

International Nuclear Information System (INIS)

Gaska, Krzysztof; Wandrasz, Andrzej J.

2008-01-01

The increasing demand for thermal and electric energy in many branches of industry and municipal management accounts for a drastic diminishing of natural resources (fossil fuels). Meanwhile, in numerous technical processes, a huge mass of wastes is produced. A segregated and converted combustible fraction of the wastes, with relatively high calorific value, may be used as a component of formed fuels. The utilization of the formed fuel components from segregated groups of waste in associated processes of co-combustion with conventional fuels causes significant savings resulting from partial replacement of fossil fuels, and reduction of environmental pollution resulting directly from the limitation of waste migration to the environment (soil, atmospheric air, surface and underground water). The realization of technological processes with the utilization of formed fuel in associated thermal systems should be qualified by technical criteria, which means that elementary processes as well as factors of sustainable development, from a global viewpoint, must not be disturbed. The utilization of post-process waste should be preceded by detailed technical, ecological and economic analyses. In order to optimize the mixing process of fuel components, a mathematical model of the forming process was created. The model is defined as a group of data structures which uniquely identify a real process and conversion of this data in algorithms based on a problem of linear programming. The paper also presents the optimization of parameters in the process of forming fuels using a modified simplex algorithm with a polynomial worktime. This model is a datum-point in the numerical modeling of real processes, allowing a precise determination of the optimal elementary composition of formed fuels components, with assumed constraints and decision variables of the task

ASSESSMENT OF THE USE FOR FERTILISATION PURPOSES INCINERATION ASH PELLETS USING GASIFICATION BURNER LESTER

Directory of Open Access Journals (Sweden)

Marzena Gibczyńska

2016-12-01

Full Text Available The use of biomass in system energetics for the purpose of increasing the share of renewable energy sources in the overall energy mix by biomass and coal co-combustion is not an optimal solution in the light of previous experience in Poland. It is appropriate to develop local biomass market for energy purposes as a basis for future distributed energy generation based on biomass. This solution facilitates the use of ash from biomass combustion for plant fertilisation. The present paper concerns the assessment of the use of ash from combustion of pellets in an innovative gasifying pellet burner – LESTER type, for soil fertilisation. The paper presents the analysis of the content of macro- and microelements in ash against the chemical composition of pellets in relation to permissible contents in fertilisers. The content of phosphorus, potassium, calcium and magnesium in bottom and fly ash from combustion of wood pellet and rye straw in LESTER gasifying burner validates the use of this material for soil fertilisation purposes. However, due to low nitrogen content – comparable to that found in soil, the material is not to be considered as fertiliser supplying this macroelement to soil. The analysed bottom ash used for fertilisation meets the conditions set out in the Regulation of the Minister of Environment of 9 September 2002. However, fly ash should be used with considerable caution due to high content of iron, zinc and nickel. The yield of bottom ash is several times higher than that of fly ash, therefore the possibility of its use in the form of mixtures in adequate proportions should be considered.

An investigation of co-combustion municipal sewage sludge with biomass in a 20kW BFB combustor under air-fired and oxygen-enriched condition.

Science.gov (United States)

Kumar, Rajesh; Singh, Ravi Inder

2017-12-01

The behavior of municipal sewage sludge (MSS) with biomass (Guar stalks (GS), Mustard Husk (MH), Prosopis Juliflora Wood (PJW)) has been investigated in a 20kW bubbling fluidized bed (BFB) combustor under both air-fired (A-F) and oxygen-enriched (O-E) conditions. The work presented is divided into three parts, first part cover the thermogravimetric analysis (TGA), second part cover the experimental investigation of BFB combustor, and third part covers the ash analysis. TGA was performed with a ratio of 50%MSS/50%biomass (GS, MH, PJW) and results show that 50%MSS/50%GS has highest combustion characteristic factor (CCF). The experimental investigation of BFB combustor was performed for two different ratios of MSS/biomass (50%/50% and 25%/75%) and the combustion characteristics of blends were distinctive under both A-F and O-E condition. Despite 50%MSS/50%GS showing the highest combustion performance in TGA analysis, it formed agglomerates during burning in BFB. Due to this formation of large amount of agglomerates, de-fluidization was observed in the combustor bed after 65-75min in A-F conditions. The rate of de-fluidization increased under O-E condition. The de-fluidization problem disappeared when the share of MSS was reduced to 25%, but small amounts of the agglomerate were still present in the bed. With oxygen enhancement, the combustion efficiency of BFB combustor was improved and flue gasses were found within permissible limit. The maximum conceivable combustion efficiency (97.1%) for BFB combustor was accomplished by using 50% MSS/50%PJW under O-E condition. Results show that a ratio of 25%MSS/75%biomass combusted successfully inside the BFB combustor and extensive work is required for efficient utilization of significant share of MSS with biomass. SEM/EDS analyses were performed for agglomerate produced and for the damaged heater to study the surface morphology and compositions. The elemental heterogeneity of fly ash generated during MSS/biomass combustion was analyzed using Microwave Plasma-Atomic Emission Spectroscopy (MP-AES). Copyright © 2017 Elsevier Ltd. All rights reserved.

Energy implications of recycling packaging materials

Energy Technology Data Exchange (ETDEWEB)

Gaines, L.L. [Argonne National Lab., IL (United States); Stodolsky, F. [Argonne National Lab., Washington, DC (United States)

1994-03-01

In 1992, Congress sought to rewrite the United States comprehensive solid waste legislation -- the Resource Conservation and Recovery Act (RCRA). Commodity-specific recycling rates were proposed for consumer-goods packaging materials and newsprint We compare the impacts on energy, materials use, and landfill volume of recycling at those rates to the impacts for alternative methods of material disposition to determine the optimum for each material. After products have served their intended uses, there are several alternative paths for material disposition. These include reuse, recycling to the same product, recycling to a lower-valued product, combustion for energy recovery, incineration without energy recovery, and landfill. Only options considered to be environmentally sound are Included. Both houses of Congress specifically excluded combustion for energy recovery from counting towards the recovery goats, probably because combustion is viewed as a form of disposal and is therefore assumed to waste resources and have n environmental effects. However, co-combustion in coal-fired plants or combustion in appropriately pollution-controlled waste-to-energy plants Is safe, avoids landfill costs, and can displace fossil fuels. In some cases, more fossil fuels can be displaced by combustion than by recycling. We compare the alternative life-cycle energies to the energies for producing the products from virgin materials. Results depend on the material and on the objective to be achieved. There are trade-offs among possible goals. For instance, paper packaging recycling conserves trees but may require greater fossil-fuel input than virgin production. Therefore, the objectives for proposed legislation must be examined to see whether they can most effectively be achieved by mandated recycling rates or by other methods of disposition. The optimal choices for the United States may not necessarily be the same as those for Europe and other parts of the world.

Present situation and objective of sewage sludge treatment and disposal; Ausgangssituation und Zielstellung der Klaerschlammbehandlung und -entsorgung

Energy Technology Data Exchange (ETDEWEB)

Wittchen, F. [BC Berlin-Consult GmbH, Berlin (Germany); Pueschel, M. [BC Berlin-Consult GmbH, Berlin (Germany)

1995-11-01

Sewage sludge is a solid-liquid mixture produced in each treatment step of a waste water treatment plant. The suitable manner of sludge treatment and disposal depends on the characteristics of the sludge such as its content of heavy metals and nutrient composition. To assess the different sludge treatment and disposal options besides the economical aspects effects on the environment must be considered. The emission of CO{sub 2} can serve as a possible approach for assessment. The dewatering and thermal drying approach for assessment. The dewatering and thermal drying causes the biggest part of CO{sub 2} emissions. They are at the same level as the CO{sub 2} which would be generated directly by total oxidation of the carbon contained in the sludge. The best way of sewage sludge disposal in accordance with the legal frame work, environmental impact and financial aspects is the co-combustion of sludge in cole power plants. The agricultural use of sludge with low heavy metal concentrations, however, is cheaper. (orig.) [Deutsch] Das Fest-Fluessig-Gemisch Klaerschlamm entsteht in jeder Reinigungsstufe einer Klaeranlage und muss anschliessend einer Behandlung zugefuehrt werden. Der Entsorgungsweg ist abhaengig von den Eigenschaften des Schlammes, wie z.B. seiner Schwermetallbelastung. Den Rahmen fuer die Klaerschlammentsorgung bilden die Regelungen des Abfallgesetzes, der Klaerschlammverordnung, der Duengemittelanwendungsverordnung, der TA Siedlungsabfall, des LAGA Merkblattes 10 (Kompost) und weiterer Verordnungen des Immissionsschutz- und Abfallrechts. Zur Bewertung der verschiedenen Entsorgungswege wurden neben den oekonomischen Aspekten auch die Auswirkungen der jeweiligen Verfahren auf die Umwelt beruecksichtigt. Es wurde fuer die oekologische Bewertung die CO{sub 2}-Emission des einzelnen Verfahrens herangezogen. Das Resultat des Vergleichs zeigt, dass der Co-Verbrennung der Vorzug zu geben ist. Bei geringen Schwermetallbelastungen bietet die landwirtschaftliche

Distribution of copper, silver and gold during thermal treatment with brominated flame retardants

International Nuclear Information System (INIS)

Oleszek, Sylwia; Grabda, Mariusz; Shibata, Etsuro; Nakamura, Takashi

2013-01-01

Highlights: • Copper, silver and gold during thermal treatment with brominated flame retardants. • Distribution of copper, silver and gold during thermal processing. • Thermodynamic considerations of the bromination reactions. - Abstract: The growing consumption of electric and electronic equipment results in creating an increasing amount of electronic waste. The most economically and environmentally advantageous methods for the treatment and recycling of waste electric and electronic equipment (WEEE) are the thermal techniques such as direct combustion, co-combustion with plastic wastes, pyrolysis and gasification. Nowadays, this kind of waste is mainly thermally treated in incinerators (e.g. rotary kilns) to decompose the plastics present, and to concentrate metals in bottom ash. The concentrated metals (e.g. copper, precious metals) can be supplied as a secondary raw material to metal smelters, while the pyrolysis of plastics allows the recovery of fuel gases, volatilising agents and, eventually, energy. Indeed, WEEE, such as a printed circuit boards (PCBs) usually contains brominated flame retardants (BFRs). From these materials, hydrobromic acid (HBr) is formed as a product of their thermal decomposition. In the present work, the bromination was studied of copper, silver and gold by HBr, originating from BFRs, such as Tetrabromobisphenol A (TBBPA) and Tetrabromobisphenol A-Tetrabromobisophenol A diglycidyl ether (TTDE) polymer; possible volatilization of the bromides formed was monitored using a thermo-gravimetric analyzer (TGA) and a laboratory-scale furnace for treating samples of metals and BFRs under an inert atmosphere and at a wide range of temperatures. The results obtained indicate that up to about 50% of copper and silver can evolve from sample residues in the form of volatile CuBr and AgBr above 600 and 1000 °C, respectively. The reactions occur in the molten resin phase simultaneously with the decomposition of the brominated resin. Gold is

Particulate and PCDD/F emissions from coal co-firing with solid biofuels in a bubbling fluidised bed reactor

Energy Technology Data Exchange (ETDEWEB)

H. Lopes; I. Gulyurtlu; P. Abelha; T. Crujeira; D. Salema; M. Freire; R. Pereira; I. Cabrita [INETI, Lisbon (Portugal). DEECA

2009-12-15

In the scope of the COPOWER project SES6-CT-2004 to investigate potential synergies of co-combustion of different biofuels with coal, a study of emissions of particulate matter and PCDD/F was carried out. The biofuels tested were meat and bone meal (MBM), sewage sludge biopellets (BP), straw pellets (SP), olive bagasse (OB) and wood pellets (WP). The tests performed include co-firing of 5%, 15% and 25% by weight of biofuels with coals of different origin. Both monocombustion and co-firing were carried out. Combustion tests were performed on a pilot fluidised bed, equipped with cyclones and air staging was used in order to achieve almost complete combustion of fuels with high volatile contents and to control gaseous emissions. Particulate matter emissions were isokinetically sampled in the stack and their particle size analysis was performed with a cascade impactor (Mark III). The results showed that most particles emitted were below 10 {mu}m (PM10) for all the tests, however, with the increasing share of biofuels and also during combustion of pure biofuels, especially olive bagasse, straw and MBM, very fine particles, below about 1 {mu}m were present. With the exception of sewage sludge, greater amounts of biofuels appeared to give rise to the decrease in particulate mean diameters and increase in PM percentages below 1 {mu}m. The formation of very fine particles could be related with the presence of aerosol forming elements such as K, Na (in the case of MBM) and Cl in biofuels, which even resulted in higher PM emissions when the ash content of fuels decreased. A correlation wasverified between the increase of PCDD/F with the decrease of PM mean diameter. This may be due to higher specific surface area and greater Cu concentration in the fly ashes. 33 refs., 11 figs., 4 tabs.

NOx, FINE PARTICLE AND TOXIC METAL EMISSIONS FROM THE COMBUSTION OF SEWAGE SLUDGE/COAL MIXTURES: A SYSTEMATIC ASSESSMENT

Energy Technology Data Exchange (ETDEWEB)

Jost O.L. Wendt

2002-08-15

This research project focuses on pollutants from the combustion of mixtures of dried municipal sewage sludge (MSS) and coal. The objective is to determine the relationship between (1) fraction sludge in the sludge/coal mixture, and (2) combustion conditions on (a) NOx concentrations in the exhaust, (b) the size segregated fine and ultra-fine particle composition in the exhaust, and (c) the partitioning of toxic metals between vapor and condenses phases, within the process. The proposed study will be conducted in concert with an existing ongoing research on toxic metal partitioning mechanisms for very well characterized pulverized coals alone. Both high NOx and low NOx combustion conditions will be investigated (unstaged and staged combustion). Tradeoffs between CO2 control, NOx control, and inorganic fine particle and toxic metal emissions will be determined. Previous research has yielded data on trace metal partitioning for MSS by itself, with natural gas assist, for coal plus MSS combustion together, and for coal alone. We have re-evaluated the inhalation health effects of ash aerosol from combustion of MSS both by itself and also together with coal. We have concluded that ash from the co-combustion of MSS and coal is very much worse from an inhalation health point of view, than ash from either MSS by itself or coal by itself. The reason is that ZnO is not the ''bad actor'' as had been suspected before, but the culprit is, rather, sulfated Zn. The MSS supplies the Zn and the coal supplies the sulfur, and so it is the combination of coal and MSS that makes that process environmentally bad. If MSS is to be burned, it should be burned without coal, in the absence of sulfur.

Fate of Cu, Cr, and As during combustion of impregnated wood with and without peat additive

Energy Technology Data Exchange (ETDEWEB)

Karin Lundholm; Dan Bostroem; Anders Nordin; Andrei Shchukarev [Umeaa University, Umeaa (Sweden). Energy Technology and Thermal Process Chemistry

2007-09-15

The EU Directive on incineration of waste regulates the harmful emissions of particles and twelve toxic elements, including copper, chromium, and arsenic. Using a 15 kW pellets-fueled grate burner, experiments were performed to determine the fate of copper, chromium, and arsenic during combustion of chromate copper arsenate (CCA) preservative wood. The fate and speciation of copper, chromium, and arsenic were determined from analysis of the flue gas particles and the bottom ash using SEM-EDS, XRD, XPS, and ICP-AES. Chemical equilibrium model calculations were performed to interpret the experimental findings. The results revealed that about 5% copper, 15% chromium, and 60% arsenic were volatilized during combustion of pure CCA-wood, which is lower than predicted volatilization from the individual arsenic, chromium, and copper oxides. This is explained by the formation of more stable refractory complex oxide phases for which the stability trends and patterns are presented. When co-combusted with peat, an additional stabilization of these phases was obtained and thus a small but noteworthy decrease in volatilization of all three elements was observed. The major identified phases for all fuels were CuCrO{sub 2}(s), (Fe,Mg,Cu)(Cr,Fe,Al)O{sub 4}(s), Cr{sub 2}O{sub 3}(s), and Ca{sub 3}(AsO{sub 4}){sub 2}(s). Arsenic was also identified in the fine particles as KH{sub 2}AsO{sub 4}(s) and As{sub 2}O{sub 3}). A strong indication of hexavalent chromium in the form of K{sub 2}CrO{sub 4} or as a solid solution between K{sub 3}Na(CrO{sub 4}){sub 2} and K{sub 3}Na(SO{sub 4}){sub 2} was found in the fine particles. Good qualitative agreement was observed between experimental data and chemical equilibrium model calculations. 38 refs., 6 figs., 2 tabs.

State of the art of large combustion plants and reference plants in Austria

International Nuclear Information System (INIS)

Boehmer, S.; Schindler, I.; Szednyj, I.; Winter, B.

2003-01-01

The aim of this study is to describe the state of the art of large combustion plants with respect to the European directive on integrated pollution prevention and control (IPPC-Directive 96/61/EG). For this purpose 10 sites where one or more thermal power or district heating plants with a rated thermal input of > 50 MW are operated were selected and described in detail. Only coal and oil fired power plants were chosen because of the larger environmental impacts compared to gas fired combustion units. Large industrial combustion plants, where in addition to regular fuels also special fuels and wastes are combusted (e.g. power plants from refineries and from the pulp and paper industry), and waste incineration plants are not treated in this study. The depiction of power plants comprises the whole chain of operation, starting from the description of the type and composition of fuels, the pretreatment and introduction into the boiler, the firing technology, measures for emission reduction (both into air and water) and treatment of solid waste and residues from combustion. Furthermore possibilities to increase energy efficiency and economic aspects are examined in this study. Also legal aspects are shortly described at the beginning of the respective chapters. An actual topic is co-combustion of biomass and waste in thermal power plants. Results of trial operation in Austrian power plants are summarized and conclusions were drawn with respect to environmental impacts of co-incineration, such as emissions into air and water, quality of solid wastes and residues from co-incineration. Important aspects such as shifting of pollutants and dilution effects are discussed. The study concludes with the chapter 'State of the art for power plants', which gives a survey of the relevant measures with particular attention to above mentioned crucial points. (author)

Leaching of arsenic, copper and chromium from thermally treated soil.

Science.gov (United States)

Kumpiene, Jurate; Nordmark, Désirée; Hamberg, Roger; Carabante, Ivan; Simanavičienė, Rūta; Aksamitauskas, Vladislovas Česlovas

2016-12-01

Thermal treatment, if properly performed, is an effective way of destroying organic compounds in contaminated soil, while impact on co-present inorganic contaminants varies depending on the element. Leaching of trace elements in thermally treated soil can be altered by co-combusting different types of materials. This study aimed at assessing changes in mobility of As, Cr and Cu in thermally treated soil as affected by addition of industrial by-products prior to soil combustion. Contaminated soil was mixed with either waste of gypsum boards, a steel processing residue (Fe 3 O 4 ), fly ash from wood and coal combustion or a steel abrasive (96.5% Fe 0 ). The mixes and unamended soil were thermally treated at 800 °C and divided into a fine fraction 0.125 mm to simulate particle separation occurring in thermal treatment plants. The impact of the treatment on element behaviour was assessed by a batch leaching test, X-ray absorption spectroscopy and dispersive X-ray spectrometry. The results suggest that thermal treatment is highly unfavourable for As contaminated soils as it increased both the As leaching in the fine particle size fraction and the mass of the fines (up to 92%). Soil amendment with Fe-containing compounds prior to the thermal treatment reduced As leaching to the levels acceptable for hazardous waste landfills, but only in the coarse fraction, which does not justify the usefulness of such treatment. Among the amendments used, gypsum most effectively reduced leaching of Cr and Cu in thermally treated soil and could be recommended for soils that do not contain As. Fly ash was the least effective amendment as it increased leaching of both Cr and As in majority of samples. Copyright © 2016 Elsevier Ltd. All rights reserved.

Combustion behaviors and kinetics of sewage sludge blended with pulverized coal: With and without catalysts.

Science.gov (United States)

Wang, Zhiqiang; Hong, Chen; Xing, Yi; Li, Yifei; Feng, Lihui; Jia, Mengmeng

2018-04-01

The combustion behaviors of sewage sludge (SS), pulverized coal (PC), and their blends were studied using a thermogravimetric analyzer. The effect of the mass ratio of SS to PC on the co-combustion characteristics was analyzed. The experiments showed that the ignition performance of the blends improved significantly as the mass percentage of SS increased, but its combustion intensity decreased. The burnout temperature (T b ) and comprehensive combustibility index (S) of the blends were almost unchanged when the mass percentage of SS was less than 10%. However, a high mass percentage of SS (>10%) resulted in a great increase in T b and a notable decrease in S. Subsequently, the effects of different catalysts (CaO, CeO 2 , MnO 2 , and Fe 2 O 3 ) on the combustion characteristics and activation energy of the SS/PC blend were investigated. The four catalysts promoted the release and combustion of volatile matters in the blended fuels and shifted their combustion profiles to a low temperature. In addition, their peak separating tendencies were obvious at 350-550 C, resulting in high peak widths. All the catalysts improved combustion activity of the blended fuel and accelerated fixed carbon combustion, which decreased the ignition temperature and burnout temperature of the fuels. CeO 2 had the best catalytic effects in terms of the comprehensive combustion performance and activation energy, followed closely by Fe 2 O 3 . However, the rare-earth compounds are expensive to be applied in the catalytic combustion process of SS/PC blend at present. Based on both catalytic effects and economy, Fe 2 O 3 was potentially an optimal option for catalytic combustion among the tested catalysts. Copyright © 2018 Elsevier Ltd. All rights reserved.

Comparing the greenhouse gas emissions from three alternative waste combustion concepts

International Nuclear Information System (INIS)

Vainikka, Pasi; Tsupari, Eemeli; Sipilä, Kai; Hupa, Mikko

2012-01-01

Highlights: ► Significant GHG reductions are possible by efficient WtE technologies. ► CHP and high power-to-heat ratio provide significant GHG savings. ► N 2 O and coal mine type are important in LCA GHG emissions of FBC co-combustion. ► Substituting coal and fuel oil by waste is beneficial in electricity and heat production. ► Substituting natural gas by waste may not be reasonable in CHP generation. - Abstract: Three alternative condensing mode power and combined heat and power (CHP) waste-to-energy concepts were compared in terms of their impacts on the greenhouse gas (GHG) emissions from a heat and power generation system. The concepts included (i) grate, (ii) bubbling fluidised bed (BFB) and (iii) circulating fluidised bed (CFB) combustion of waste. The BFB and CFB take advantage of advanced combustion technology which enabled them to reach electric efficiency up to 35% and 41% in condensing mode, respectively, whereas 28% (based on the lower heating value) was applied for the grate fired unit. A simple energy system model was applied in calculating the GHG emissions in different scenarios where coal or natural gas was substituted in power generation and mix of fuel oil and natural gas in heat generation by waste combustion. Landfilling and waste transportation were not considered in the model. GHG emissions were reduced significantly in all of the considered scenarios where the waste combustion concepts substituted coal based power generation. With the exception of condensing mode grate incinerator the different waste combustion scenarios resulted approximately in 1 Mton of fossil CO 2 -eq. emission reduction per 1 Mton of municipal solid waste (MSW) incinerated. When natural gas based power generation was substituted by electricity from the waste combustion significant GHG emission reductions were not achieved.

Sewage sludge disposal at the city of Duesseldorf - Conception of co-combustion in a coal power plant; Klaerschlammentsorgung der Stadt Duesseldorf - Konzeption der Mitverbrennung im Kraftwerk

Energy Technology Data Exchange (ETDEWEB)

Lindert, M. [Umweltamt der Landeshauptstadt Duesseldorf (Germany); Hansmann, G. [Stadtwerke Duesseldorf AG (Germany); Mittmann, H. [Kanal- und Wasserbauamt der Landeshauptstadt Duesseldorf (Germany); Goertz, W. [Umweltamt der Landeshauptstadt Duesseldorf (Germany)

1995-11-01

Simultaneously to the enlargement of the biological wastewater treatment plants in Germany the amount of sludges increased. For the reuse or disposal of these sludges different methods - from agricultural use to incineration - are applied. For the city of Duesseldorf it became necessary to outline a new conception for the sludge disposal. A number of methods has been considered, showing that co-incineration in a coal-power-plant appears to be practicable under the circumstances found in Duesseldorf. Hence the effects of such a co-incineration on the emissions and the composition of solid waste materials of the power plant have been investigated in the course of an experimental operation. These experiments show that coincineration of the sludge also has advantages from the ecological point of view. (orig.) [Deutsch] Mit dem Ausbau der biologischen Klaeranlagen in Deutschland stieg in den letzten Jahren auch die Menge des anfallenden Klaerschlamms. Zur Verwertung bzw. Entsorgung dieses Schlammes werden unterschiedliche Verfahren - von der landwirtschaftlichen Verwertung bis zur Verbrennung - herangezogen. Fuer die Stadt Duesseldorf ergab sich die Notwendigkeit, die Klaerschlammentsorgung neu zu konzipieren. Verschiedene Varianten wurden geprueft, wobei die Mitverbrennung in der Schmelzkammerfeuerung eines Steinkohlekraftwerkes unter den in Duesseldorf herrschenden Randbedingungen praktikabel erschien. Daher wurden die Auswirkungen einer solchen Mitverbrennung auf das Emissionsverhalten und die Zusammensetzung der festen Reststoffe des Kraftwerks waehrend eines Probebetriebes untersucht. Die Versuche zeigen, dass die Mitverbrennung auch aus oekologischer Sicht Vorteile aufweist. (orig.)

Combustion, cofiring and emissions characteristics of torrefied biomass in a drop tube reactor

International Nuclear Information System (INIS)

Ndibe, Collins; Maier, Jörg; Scheffknecht, Günter

2015-01-01

The study investigates cofiring characteristics of torrefied biomass fuels at 50% thermal shares with coals and 100% combustion cases. Experiments were carried out in a 20 kW, electrically heated, drop-tube reactor. Fuels used include a range of torrefied biomass fuels, non-thermally treated white wood pellets, a high volatile bituminous coal and a lignite coal. The reactor was maintained at 1200 °C while the overall stoichiometric ratio was kept constant at 1.15 for all combustion cases. Measurements were performed to evaluate combustion reactivity, emissions and burn-out. Torrefied biomass fuels in comparison to non-thermally treated wood contain a lower amount of volatiles. For the tests performed at a similar particle size distribution, the reduced volatile content did not impact combustion reactivity significantly. Delay in combustion was only observed for test fuel with a lower amount of fine particles. The particle size distribution of the pulverised grinds therefore impacts combustion reactivity more. Sulphur and nitrogen contents of woody biomass fuels are low. Blending woody biomass with coal lowers the emissions of SO 2 mainly as a result of dilution. NO X emissions have a more complex dependency on the nitrogen content. Factors such as volatile content of the fuels, fuel type, furnace and burner configurations also impact the final NO X emissions. In comparison to unstaged combustion, the nitrogen conversion to NO X declined from 34% to 9% for air-staged co-combustion of torrefied biomass and hard coal. For the air-staged mono-combustion cases, nitrogen conversion to NO X declined from between 42% and 48% to about 10%–14%. - Highlights: • Impact of torrefaction on cofiring was studied at high heating rates in a drop tube. • Cofiring of torrefied biomasses at high thermal shares (50% and higher) is feasible. • Particle size impacts biomass combustion reactivity more than torrefaction. • In a drop tube reactor, torrefaction has no negative

Combustion of Waste Wood. Second phase of the collaboration project on waste wood combustion

International Nuclear Information System (INIS)

Andersson, Annika; Andersson, Christer; Eriksson, Jan; Hemstroem, Bengt; Jungstedt, Jenny; Kling, Aasa; Bahr, Bo von; Ekvall, Annika; Eskilsson, David; Tullin, Claes; Harnevie, Henrik; Sieurin, Jan; Keihaes, Juha; Mueller, Christian; Berg, Magnus; Wikman, Karin

2003-08-01

Combustion of waste wood has during the last decade increased dramatically and this has resulted in a number of Swedish plants using this fuel, e.g. Handeloe P11 (Norrkoeping) and ldbaecken P3 (Nykoeping), and yet other plants that are under construction (e.g. Nynaeshamn). The experience from these plants are that waste wood combustion results in a number of operational problems. To some extent these problems are different compared with the problems related to combustion of other biofuels but the situation is not directly comparable to waste incinerators. The problems are mainly related to slagging and fouling of heat exchanger surfaces and accelerated corrosion at relatively low temperature compared to the situation for ordinary biofuels. In some cases an increase in the emissions of specific substances can also result in difficulties to fulfil the EC-directive on waste combustion. Within previous projects the main problems related to combustion of waste wood have been identified and to some extent the cause of these problems has been clarified. One result of this reported investigation is a deeper understanding of the actual causes of these problems. However, the most important result is a number of recommendations for different measures on how to achieve disturbance-free combustion of waste wood. These recommendations actually summarises the most important possible solutions on how to achieve a disturbance-free operation and a lower maintenance cost for boilers combusting waste wood and can thereby be regarded as a short summery of the whole project: 1) Improving fuel quality by Improved sorting at the source and Sieving of the fuel -> Reducing the amount of metals and chlorine and Separation of fines and thereby reducing the amount of metals. 2) Combustion modifications by Avoiding reducing conditions at the heat exchanger surfaces -> Minimising slagging, fouling and corrosion. 3) Additives or co-combustion by Addition of sulphur with the fuel; Injection of

Study of flame combustion of off-design binary coal blends in steam boilers

Science.gov (United States)

Kapustyanskii, A. A.

2017-07-01

proves the existence of the synergetic effect in the processes of cocombustion of coals of various grades.

Synthesis of Vaermeforsk's research programme 'Crops from field to energy'; Syntes av Vaermeforsks forskningsprogram 'Groedor fraan aaker till energi'

Energy Technology Data Exchange (ETDEWEB)

Bubholz, Monika; Forsberg, Maya; Gunnarsson, Carina; Roennbaeck, Marie; Olsson, Johanna

2010-06-15

Vaermeforsk and the Swedish Farmers' Foundation for Agricultural Research (SLF), have jointly run the research programme 'Crops from field to energy'. The long-term aim of the programme is to increase production and utilization of bioenergy from agriculture for combustion and heat and power production in Sweden. About 20 projects have studied different parts of the chain from cultivation, harvest and storage to combustion and recycling of ash to farmland for agricultural fuels (straw, hemp, Reed Canary Grass and short rotation willow crops (Salix)). The aim of this report has been to compile and synthesise progress made during the programme and realization of its aims, as well as to identify the need of further research. The most important progress and conclusions made during the programme are: Cultivation - More knowledge and concrete advice concerning planting and growth of Salix, as well as on suitable length of harvest season, which enables planting cost reductions and increased yields. Increased knowledge on cultivation of Reed Canary Grass and combined cultivation with leguminous plants. Harvest and logistics - Comparisons and costs for different alternatives for harvest, handling and logistics has been produced for all of the agricultural fuels, both via theoretical and practical efforts, which can serve as a basis for direct measures as well as continued research. Processing/combustion/ash - It is possible to produce briquettes made from Reed Canary Grass and peat. New knowledge on combustion of Reed Canary Grass with different boilers is produced. It is now recommended as a fuel for co-combustion with wood and peat in large scale plants. Recommendations on co-combustion of Reed Canary Grass and Salix with peat have also been put forward, based on combustion tests. Experience from Denmark on large scale combustion of straw and production of high quality straw has been compiled. Additional costs that may arise when using agricultural fuels

JV Task 6 - Coal Ash Resources Research Consortium Research

Energy Technology Data Exchange (ETDEWEB)

Debra Pflughoeft-Hassett; Tera Buckley; Bruce Dockter; Kurt Eylands; David Hassett; Loreal Heebink; Erick Zacher

2008-04-01

The Coal Ash Resources Research Consortium{reg_sign} (CARRC{reg_sign}, pronounced 'cars') focuses on performing fundamental and applied scientific and engineering research emphasizing the environmentally safe, economical use of coal combustion by-products (CCBs). CARRC member organizations, which include utilities and marketers, are key to developing industry-driven research in the area of CCB utilization and ensuring its successful application. The U.S. Department of Energy is a partner in CARRC through the EERC Jointly Sponsored Research Program (JSRP), which provides matching funds for industrial member contributions and facilitates an increased level of effort in CARRC. CARRC tasks were designed to provide information on CCB performance, including environmental performance, engineering performance, favorable economics, and improved life cycle of products and projects. CARRC technical research tasks are developed based on member input and prioritization. CARRC special projects are developed with members and nonmembers to provide similar information and to support activities, including the assembly and interpretation of data, support for standards development and technology transfer, and facilitating product development and testing. CARRC activities from 1998 to 2007 included a range of research tasks, with primary work performed in laboratory tasks developed to answer specific questions or evaluate important fundamental properties of CCBs. CARRC topical reports were prepared on several completed tasks. Specific CARRC 1998B2007 accomplishments included: (1) Development of several ASTM International Standard Guides for CCB utilization applications. (2) Organization and presentation of training courses for CCB professionals and teachers. (3) Development of online resources including the Coal Ash Resource Center, Ash from Biomass in Coal (ABC) of cocombustion ash characteristics, and the Buyer's Guide to Coal-Ash Containing Products. In addition

Long term effects of ash fertilization of reed canary grass; Laangtidseffekter av askgoedsling vid roerflensodling

Energy Technology Data Exchange (ETDEWEB)

Palmborg, Cecilia; Lindvall, Eva

2011-03-15

harvest. The main component of the ash is silica and silica concentrations are higher when reed canary grass is grown on clay soil than on peat soil. In an earlier project within the department of agricultural research for northern Sweden, SLU Umea, reed canary grass growing on peat soil was fertilized with ash from cocombustion of reed canary grass and sorted municipal waste. This ash was beneficial for the growth of the grass and did not give increased heavy metal contents. However the experiment only lasted two years so no conclusions could be drawn about long-term effects. Crop yields and elemental composition of the crop: The yields varied very much from year to year. The first two production years, 2004 and 2005 the yield was at expected levels, 6000-7000 kg dry matter per ha and year. After that, 2006-2009 the yields have been lower than expected, 1500 - 4000 kg dry matter per ha and year. The reason for this is not known, but it could be related to climate or pests. There were no significant differences in yield between the treatments. Samples from each plot from the last harvest and stored samples from 2004 were analyzed for nutrient and heavy metal content. There were only minor significant differences between the treatments: The ash and the potassium and calcium concentrations 2009 in grass from treatment A, ash from co-combustion of reed canary grass and waste, was slightly higher than in the NPK fertilized control. The magnesium concentration in 2009 was slightly higher in grass fertilized with reed canary grass ash than in the control grass. Element balances and soil concentrations of elements: Because of the low yield levels the amounts of P and K applied were much higher than the removal with harvests (Table 2). This resulted in an increase in plant available P and K in the top soil between 2003 and 2008 (Table 3). However, in the subsoil there was a decrease especially in plant available P. The only significant differences in soil nutrients between the

Elaboration of a Platform for Increasing Straw Combustion in Sweden, based on Danish Experiences

Energy Technology Data Exchange (ETDEWEB)

Hinge, Joergen (Danish Technological Inst. (Denmark))

2009-05-15

The report forms the background for planning a straw-fired CHP plant through recommendations based on Danish experiences. Almost all straw for large scale combustion in Denmark is produced and handled as 'big bales' (500-600 kg). Other systems with chaffed straw and straw pellets have been investigated. But even though 120,000 tonnes of straw pellets is used annually at one plant, this is not considered a feasible alternative to handling in big bales--especially not when considering establishment a new plant. In general, there are no major problems with straw quality. Quality measures are regulated in the contract/terms of delivery between producer and buyer, and each load of straw bales is visually inspected, whereas moisture content is measured automatically. Up to 20% average moisture content is in general acceptable (although not ideal), and most plants are quite flexible with regard to type of straw. Experiences and data have been collected from a number of plants. The plants were selected, so that the different combustion principles were represented. Special attention has been given to the choice of technical solutions at the most recently established plant at Fynsvaerket. Co-firing of coal and straw has proved a viable technology with low investment costs, when an existing conventional coal-fired boiler is modified for co-combustion. Corrosion has not been a problem, as ash from coal is considered to neutralize the difficult substances (chloride, potassium) from straw combustion. The limiting factor can however be whether legislation permits the utilization of the mixed ash for concrete production; Danish legislation has been adapted to this. A separate boiler can be built and operated without any major problems. The investments are much higher for a given amount of straw to be burnt, than the co-firing technology. However, separate biomass boilers offer the opportunity of using different types of biomass in varying combinations. Problems with

Where does the energy for hydrogen production come from? Status and alternatives. 3. ed.

International Nuclear Information System (INIS)

Schindler, J.; Wurster, R.; Zerta, M.; Blandow, V.; Zittel, W.

2011-05-01

This brochure addresses and endeavours to find answers to the question as to the future availability of energy commodities. One point requiring clarification here is how long the production rates of crude oil, natural gas and coal will keep pace with and satisfy the rising demand. Particularly with regard to coal, it further needs to be clarified when, to what extent and for what period of time the separation and safe storage of carbon dioxide from fossil combustion will be possible, this being a prerequisite for the production of energy from coal. Then it needs to be clarified what contribution can realistically be expected from nuclear energy. The brochure also assesses the potentials of renewable energies for covering energy demand. It presents the cost reduction potentials in wind power and photovoltaics and the potential for producing motor fuels from renewable energy. Here it places a special emphasis on hydrogen. In conclusion it can be said that the downturn in oil production soon to be expected will leave a gap which can be closed neither by other fossil fuels nor by nuclear energy resources. On the other side, even though renewable energies will grow rapidly over the coming decades, their contribution will for some time yet be too small to be able to close this gap. This means that there is no way around making more efficient use of energy across all stages of production and use. It is also seen that biofuels will not keep the world moving as it is now and that hydrogen will therefore become a significant motor fuel. The use of hydrogen will only become dispensable if it proves possible to develop electromobiles with acceptable properties (storage density, service life, cold start behaviour, price). However, this appears improbable from today's perspective. One rollout strategy available at short term in Germany would be to use byproduct hydrogen from the chemical industry for the first vehicle fleets. Today, this hydrogen is mainly used thermally by co-combustion

Pre-treatment of biofuels for power production. Final report (1998). K. Joule 3 - OPTEB, Task: No. 19/20

Energy Technology Data Exchange (ETDEWEB)

Jensen, P.A.; Sander, B.; Dam-Johansen, K.

1999-10-01

Co-firing of straw and coal on existing pulverised coal fired power plants may cause problems with deposition, corrosion, deactivation of SCR catalysts and impedes the utilisation of the fly ash, because of the high chlorine and potassium content of straw. Experiments with co-combustion of straw and coal on boilers plants have shown, that when maximal 20% of straw on a thermal basis is applied the most serious problems is the deactivation of high dust SCR catalysts and the deterioration of fly ash quality. The objective of this work was to evaluate a large-scale pre-treatment process for straw. The process applies pyrolysis at a moderate temperature, where the alkaline is retained in the char. The char is then washed and char and pyrolysis gasses can be co-fired with coal without causing serious problems. Fundamental laboratory studies as well as technical investigations were conducted to evaluate the pre-treatment concept. The laboratory studies were mainly done to improve the understanding of potassium and chlorine release during pyrolysis and the extraction of char with water. Some work were also done with respect to particle characterisation, straw pyrolysis kinetic and straw char combustion. The technical evaluation of a plant with 20 tons/hour capacity included investigations of possible reactor technologies, waste water handling, power efficiency and investment costs. Based on the laboratory experiments a pyrolysis temperature of 500 to 600 deg. C is recommended for the pre-treatment process. A high degree of pyrolysis is obtained without a significant release of potassium to the gas, but a release of 30 to 60% of the chlorine can not be avoided. Extraction of potassium from char with water is a two-step process, where the first step is a fast dissolution of potassium salts and the second step is a slow release of potassium from the interior of the char particle. A high potassium removal during char wash could not be obtained for all types of char within

6. conference: Thermal waste management; 6. Fachtagung: Thermische Abfallbehandlung

Energy Technology Data Exchange (ETDEWEB)

Faulstich, M.; Urban, A.; Bilitewski, B. (eds.)

2001-07-01

This conference was held at Garching near Munich on June 18 - 20, 2001. Legal and political aspects were discussed, i.e. new national and international legislation and the implementation of EC regulations into German law, e.g. in the fields of waste dumping, incineration, and 'best technology'. Refuse-derived fuels are gone into, e.g. construction site waste, residues of the paper industry, plastic waste, sorted waste fractions, waste oil, animal meal, etc., as well as technologies and plants for co-combustion of refuse-derived fuels. Another section discussed 'classic' incinerators and their optimisation and innovation potential. Selected new concepts for furnaces, boilers, corrosion reduction and flue gas purification were discussed. Not least, the cost aspect is getting increasingly important. Benchmarking and the internet are addressed. The conference has become an important forum for producers, operators, planners and consultants, administrators and scientists in the field of thermal waste management. [German] Vom 18. bis 20. Juni 2001 fand in Garching bei Muenchen wieder die Fachtagung 'Thermische Abfallbehandlung' statt. Der rechtliche und politische Rahmen wird von den neuen nationalen und internationalen Gesetzen und Verordnungen gepraegt, vor allem durch die Umsetzung mehrerer europaeischer Richtlinien in deutsches Recht, beispielsweise zur Abfalldeponierung, zur Verbrennung von Abfaellen sowie zur bestverfuegbaren Technik. Ein grosser Themenblock ist dem Brennstoff aus Muell gewidmet, welcher bereits vor ueber zwanzig Jahren ein grosses Thema war. Mittlerweile scheinen Ersatz- und Sekundaerbrennstoffe fuer viele der Koenigsweg bei der Loesung der abfallwirtschaftlichen Probleme zu sein. Daher sind hier ausfuehrliche Informationen zu etlichen potenziellen Brennstoffen wie Baustellenabfaelle, Spuckstoffe aus der Papierindustrie, Kunststoffabfaelle, DSD-Sortierreste, Altoel, Tiermehl usw. zu finden. Fuer derartige

Engineering models for low-NO{sub x} burners

Energy Technology Data Exchange (ETDEWEB)

Storm Pedersen, Lars

1997-08-01

The present Ph.D. thesis describes a theoretical investigation of NO formation in pulverised coal combustion and an experimental investigation of co-combustion of straw and pulverised coal. The theoretical work has resulted in a simplified mathematical model of a swirling pulverised coal flame able to predict the NO emission and the burnout of coal. In order to simplify the flow pattern of a confined swirling flame, the residence time distribution (RTD) in a swirling pulverised coal flame was determined. This was done by using the solution of a detailed fluid dynamic mathematical model for a 2.2 MW{sub th} and a 12 MW{sub th} pulverised coal flame. From the mathematical solution the RTD was simulated by tracing a number of fluid particles or inert particles. The RTD in the near burner zone was investigated by use of the mathematical model for the 2.2 MW{sub th} and 12 MW{sub th} flame. Results showed that the gas phase in the near burner zone may be approximated as a CSTR and that the mean residence time increased with particle size. In pulverised coal flames, the most important volatile nitrogen component forming NO{sub x} is HCN. To be able to model the nitrogen chemistry in coal flames it is necessary to have an adequate model for HCN oxidation. In order to develop a model for HCN/NH{sub 3}/NO conversion, a systematic reduction of a detailed chemical kinetic model was performed. Based on the simplification of the flow pattern for a swirling flame and the reduced chemistry developed, a chemical engineering model of pulverised coal flame was established. The objectives were to predict the NO emission, the CO emission, and the burnout of char. The effects of co-firing straw and pulverised coal was investigated in a 2.5 MW{sub th} pilot-scale burner and a 250 MW{sub e} utility boiler. In the 2.5 MW{sub th} trial the straw was chopped and fed separately to the burner, whereas in the full-scale experiment the straw was pre-processed as pellets and pulverised with the

Combustion of Biosolids in a Bubbling Fluidized Bed, Part 1: Main Ash-Forming Elements and Ash Distribution with a Focus on Phosphorus.

Science.gov (United States)

Skoglund, Nils; Grimm, Alejandro; Ohman, Marcus; Boström, Dan

2014-02-20

calcium and magnesium were also found in the bed ash. Both the formation of aluminum-containing alkali silicates and inclusion of calcium and magnesium in bed ash could assist in preventing bed agglomeration during co-combustion of biosolids with other renewable fuels in a full-scale bubbling fluidized bed.

Gasification of biomass for energy production. State of technology in Finland and global market perspectives

International Nuclear Information System (INIS)

Wilen, C.; Kurkela, E.

1997-01-01

gasification technology developers in Finland. In 1993, a biomass IGCC demonstration plant based on Foster Wheeler gasification technology and owned by the Swedish utility company Sydkraft was commissioned in Sweden. The plant is the first combined-cycle plant for generating electricity from fuel gas produced entirely from biomass. Atmospheric-pressure gasification of biomass fuels is a simpler and cheaper technology than pressurized gasification. Co-combustion is a promising new alternative, in which the biomass gasification is integrated to a pulverised coal-fired boiler. The concept will be demonstrated by Foster Wheeler Energia Oy and a municipal power company. (orig.) 64 refs

Gasification of biomass for energy production. State of technology in Finland and global market perspectives

Energy Technology Data Exchange (ETDEWEB)

Wilen, C.; Kurkela, E. [VTT Energy, Espoo (Finland). Energy Production Technologies

1997-12-31

the main gasification technology developers in Finland. In 1993, a biomass IGCC demonstration plant based on Foster Wheeler gasification technology and owned by the Swedish utility company Sydkraft was commissioned in Sweden. The plant is the first combined-cycle plant for generating electricity from fuel gas produced entirely from biomass. Atmospheric-pressure gasification of biomass fuels is a simpler and cheaper technology than pressurized gasification. Co-combustion is a promising new alternative, in which the biomass gasification is integrated to a pulverised coal-fired boiler. The concept will be demonstrated by Foster Wheeler Energia Oy and a municipal power company. (orig.) 64 refs.

Effect of limestone addition on chlorine compound emissions in grate and fluidized-bed combustion of recovered fuels

International Nuclear Information System (INIS)

Vesterinen, R.; Ruuskanen, J.

2000-01-01

The aim was to verify the positive results of laboratory experiments concerning the reducing effect of limestone addition on emissions of organic chlorine compounds and acidifying compounds (HCl, HF, SO 2 ) in grate and fluidized-bed combustion of recovered fuels in commercial boilers. The final aim is to develop a cheap and practical way of reducing emissions of organic chlorine compounds in co-combustion of recovered fuels. Pellets produced from the mixture of recovered fuel and limestone is a product ready for use in plants without any need of additional employees or equipment for limestone feed. Pellets produced by Ewapower Oy are used as recovered fuel and Gotland limestone of Partek Nordkalk Oyj Abp as limestone. Ewapower Oy produces pellets by feeding a certain proportion of limestone among recovered fuel at the production stage. Experiments are carried out in one grate-combustion plant and in one or two fluidized-bed plants. The first experiments were carried out in a 3 MWth BioGrate boiler at the new heating station of Pielavesi municipality in autumn 1999. The flue gases are cleaned with a cyclone (FinCleaner). The main fuel was a mixture of bark and sawdust (3:1) from a sawmill. Ewapower pellets with an addition of Gotland limestone were used as recovered fuel. The experiments were carried out at about 2 MW boiler output. Temperatures of the furnace and flue gas, pressure and fuel gas composition were measured continuously. For determining the composition of gas, O 2 , CO, CO 2 , hydrocarbons and N 2 O(FTIR), NO x and SO 2 were measured continuously. HCl, heavy metals (As, Cd, Cr, Cu, Hg, Ni, Pb, Zn), polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/PCDF), polyaromatic hydrocarbons (PAH), chlorobenzenes, chlorophenols and PCB were measured as one-shot determinations. Fuel and ash samples were also collected during the experiments. The organic compounds were analyzed by the Department of Environmental Science of the University of Kuopio, which is

Nutrient supply to reed canary grass as a bioenergy crop. Intercropping and fertilization with ash or sewage sludge

Energy Technology Data Exchange (ETDEWEB)

Lindvall, Eva

2012-07-01

Production of renewable energy from herbaceous crops on agricultural land is of great interest since fossil fuels need to be replaced with sustainable energy sources. Reed canary grass (RCG), Phalaris arundinacea L. is an interesting species for this purpose. The aim of this thesis was to study different approaches to reduce the requirement of mineral fertilizers in RCG production for bioenergy purposes. Paper I describes a study where fertilization effects and risk of heavy metal enrichment were studied, using annual applications of ash for seven years. Ash from co-combustion of RCG and municipal wastes (mixed ash), pure RCG ash and commercial fertilizers were compared. The experiment was harvested each spring. Paper II describes an ongoing study in which the effects of intercropping RCG in mixture with nitrogen-fixing perennial legumes are examined in two experiments, in combination with various fertilization treatments. Three fertilization treatments were applied: high N, low N (half of the high N) and low N + RCG ash/sewage sludge. A delayed harvest method was used; cutting the biomass in late autumn and harvesting in spring. Besides dry matter yield, the N-fixation rate was estimated. The results from paper I showed no differences between treatments in the dry matter yields or in the heavy metal concentrations in the biomass. Soil samples, taken when the experiment was finished, showed differences between treatments for Cd, Pb and Zn only in the uppermost soil level, highest levels for the mixed ash treatment. The results in paper II showed that at one site the legume proportion in the mixtures was low and did not affect RCG growth negatively. The high N treatment gave a higher spring yield than the low N treatments. Mean rates of N2-fixation in the first production year were 12-28, 33-40 and 55 kg N ha-1 kg for goat's rue (Galega orientalis Lam.), red clover (Trifolium pratense L.), and alsike clover (Trifolium hybridum L.), plots, respectively. At the

Combustion of Coal-Mule Briquettes / Spalanie Brykietów Z Mułu Węglowego

Science.gov (United States)

Kijo-Kleczkowska, Agnieszka

2013-09-01

Combustion technologies coal-mule fuels create a number of new possibilities for organising combustion processes so that they fulfil contemporary requirements (e.g., in terms of the environment protection- related issues). The paper describes the problems of coal-mule fuel combustion that have acquired a wider significance as the quality requirements of coal combustion in power plants have been growing. Coal mines that want to fulfill expectations of power industry workers have been forced to develop and modernize plants of coal wet cleaning. It all results in the growing amount of waste arising in the process of coal wet cleaning which contains smaller and smaller coal undersizes. In this situation the concept of direct combustion of the above mentioned waste and their co-combustion with other fuels, coal and biomass, seems to be attractive. Biomass is one from the most promising sources of renewable energy. The main aim of the paper is to identify the mechanism and kinetics of combustion of coal-mule fuels and their co- -combustion with coal and biomass in the briquettes form based on extensive experimental research in air. Niekorzystny bilans paliwowy naszego kraju powoduje nadmierne obciążenie środowiska, wywołane emisją CO2, NOx, SO2 i pyłów, a także powiększeniem powierzchni koniecznych na składowanie wciąż narastających stałych odpadów paleniskowych. Górnictwo, od którego energetyka oczekuje coraz lepszego paliwa, musi stosować głębsze wzbogacanie węgla. Powoduje to ciągłą produkcję odpadów w postaci mułów poflotacyjnych. Najlepszą metodą utylizacji tych mułów jest ich spalanie w postaci zawiesin, a także ich współspalanie z innymi paliwami, węglem czy biomasą. Biomasa jest bowiem jednym z najbardziej obiecujących źródeł OZE, a jej współspalanie z paliwami węglowymi znajduje w ostatnich latach coraz szersze zastosowanie zarówno w kraju, jak i na świecie. W tej sytuacji istotne jest prowadzenie badań naukowych

A new method to quantify fluidized bed agglomeration in the combustion of biomass fuels

Energy Technology Data Exchange (ETDEWEB)

Oehman, M. [Umeaa Univ. (Sweden). Dept. of Chemistry

1997-12-31

The present licentiate thesis is a summary and discussion of four papers, dealing with the development, evaluation and use of a new method to quantify bed agglomeration tendencies for biomass fuels. An increased utilization of biomass related fuels has many environmental benefits, but also requires careful studies of potential new problems associated with these fuels such as bed agglomeration/defluidization during combustion and gasification in fluidized beds. From a thorough literature survey, no suitable methods to determine bed agglomeration tendencies of different fuels, fuel combinations or fuels with additives appeared to be available. It therefore seemed of considerable interest to develop a new method for the quantification of fluidized bed agglomeration tendencies for different fuels. A bench scale fluidized bed reactor (5 kW), specially designed to obtain a homogeneous isothermal bed temperature, is used. The method is based on controlled increase of the bed temperature by applying external heat to the primary air and to the bed section walls. The initial agglomeration temperature is determined by on- or off-line principal component analysis of the variations in measured bed temperatures and differential pressures. Samples of ash and bed material for evaluation of agglomeration mechanisms may also be collected throughout the operation. To determine potential effects of all the process related variables on the determined fuel specific bed agglomeration temperature, an extensive sensitivity analysis was performed according to a statistical experimental design. The results showed that the process variables had only relatively small effects on the agglomeration temperature, which could be determined to 899 deg C with a reproducibility of {+-} 5 deg C (STD). The inaccuracy was determined to be {+-} 30 deg C (STD). The method was also used to study the mechanism of both bed agglomeration using two biomass fuels and prevention of bed agglomeration by co-combustion

International seminar on biomass and fossil fuels co-firing in power plants and heating plants in Europe; Seminaire international sur la cocombustion de biomasse et d'energies fossiles dans les centrales electriques et les chaufferies en Europe

Energy Technology Data Exchange (ETDEWEB)

NONE

2001-07-01

The aim of the European commission which has fixed to 12% the share of renewable energies in the total energy consumption up to 2010, is to develop the biomass sector. Co-firing is a solution that allows to increase significantly the use of biomass because it does not require important investments. Today, about 150 power plants in Europe use co-firing. An Altener project named 'Cofiring' has ben settled in order to bring together and analyze the European experience in this domain and to sustain and rationalize the design of future projects. The conclusions of this study, coordinated by VTT Energy and which involves CARMEN (Germany), CBE (Portugal), the Danish centre for landscape and planning, ITEBE (France), KOBA (Italy), SLU (Sweden), and EVA (Austria), were presented during this international seminar. (J.S.)

Long term deactivation test of high dust SCR catalysts by straw co-firing

Energy Technology Data Exchange (ETDEWEB)

Weigang Lin; Degn Jensen, A.; Bjerkvig, J.

2009-12-15

The consequences of carbon dioxide induced global warming cause major concern worldwide. The consumption of energy produced with fossil fuels is the major factor that contributes to the global warming. Biomass is a renewable energy resource and has a nature of CO{sub 2} neutrality. Co-combustion of biomass in existing coal fired power plants can maintain high efficiency and reduce the emission of CO{sub 2} at same time. However, one of the problems faced by co-firing is deactivation of the SCR catalysts. Understanding of the mechanisms of deactivation of the catalyst elements at co-firing conditions is crucial for long term runs of the power plants. Twenty six SCR catalyst elements were exposed at two units (SSV3 and SSV4) in the Studstrup Power Plant for a long period. Both units co-fire coal and straw with a typical fraction of 8-10% straw on an energy basis during co-firing. SSV4 unit operated in co-firing mode most of the time; SSV3 unit co-fired straw half of the operating time. The main objective of this PSO-project is to gain knowledge of a long term influence on catalyst activity when co-firing straw in coal-fired power plants, thus, to improve the basis for operating the SCR-plants for NO{sub x}-reduction. The exposure time of the applied catalyst elements (HTAS and BASF) varied from approximately 5000 to 19000 hours in the power plant by exchanging the element two times. The activity of all elements was measured before and after exposure in a bench scale test rig at the Department of Chemical and Biochemical Engineering, Technical University of Denmark. The results show that the activity, estimated by exclusion of channel clogging of the elements, decreases gradually with the total exposure time. It appears that the exposure time under co-firing condition has little effect on the deactivation of the catalyst elements and no sharp decrease of the activity was observed. The average deactivation rate of the catalyst elements is 1.6 %/1000 hours. SEM

Ring Formation in Lime Kilns; Ringbildning i Mesaugnar II

Energy Technology Data Exchange (ETDEWEB)

Dhak, Janice [AaF-Process AB, Stockholm (Sweden)

2003-07-15

The key to a cost efficient and high performance pulp production is low variations in the production level. Despite the fact that all pulp mills always work with improvements to eliminate problems with ring formations, AaF has at several mill seen that the operation of a lime kiln still often is disturbed by ring formation. In 1999 AAF made an extensive investigation of more than 10 lime kilns in Sweden, considering operational data, kiln data and lime chemical analyzes. The result pointed out the importance of how the lime kiln is operated and that dead load and contaminants in the lime was less important. The report suggested that it is the difference in the temperature between the flue gas and the lime that is of importance. There are no quantified process values available that guides for a 'best practice' way to run a lime kiln to avoid ring formation. The goal with this project has been to develop a strategy for operation of a kiln in a way that lowers the risk for ring formation. The results from simulations of a number of lime kilns in this project could not proof that a low difference in the temperature between the flue gas and the lime was the main cause of problems with ring formation and thus it was not possible to quantify the optimal difference to avoid rings. Probably the most important information from the simulations was that it is not the temperature difference in number of degrees that is of importance, rather the fact that the temperature difference in the kalcining zone varies, and time to time reach below the critical level were lime occasionally is cooled down. It can be the case if the temperature profile of the flue gas temporarily changes or if the lime mud temperature profile is changed. The reason for changes in the temperature profile is discussed in the report. The most important factors discussed are: Variations in the energy input e.g. oil and methanol/strong gases in cocombustion. One single fuel is easier to control

Biomass CFB gasifier connected to a 350 MW{sub t}h steam boiler fired with coal and natural gas - THERMIE demonstration project in Lahti in Finland

Energy Technology Data Exchange (ETDEWEB)

Palonen, J. [Foster Wheeler Energia Oy, Varkaus (Finland). Varkaus Global New Products

1997-12-31

Laempoevoima Oy`s Kymijaervi power plant gasification project is to demonstrate the direct gasification of wet biofuel and the use of hot, raw and very low-calorific gas directly in the existing coal-fired boiler. The gasification of biofuels and co-combustion of gases in the existing coal-fired boiler offers many advantages such as: recycling of CO{sub 2}, decreased SO{sub 2} and NO{sub x} emissions, efficient way to utilize biofuels and recycled refuse fuels, low investment and operation costs, and utilization of the existing power plant capacity. Furthermore, only small modifications are required in the boiler, possible disturbances in the gasifier do not shut down the power plant. (author)

Biomass CFB gasifier connected to a 350 MW{sub t}h steam boiler fired with coal and natural gas - THERMIE demonstration project in Lahti in Finland

Energy Technology Data Exchange (ETDEWEB)

Palonen, J [Foster Wheeler Energia Oy, Varkaus (Finland). Varkaus Global New Products

1998-12-31

Laempoevoima Oy`s Kymijaervi power plant gasification project is to demonstrate the direct gasification of wet biofuel and the use of hot, raw and very low-calorific gas directly in the existing coal-fired boiler. The gasification of biofuels and co-combustion of gases in the existing coal-fired boiler offers many advantages such as: recycling of CO{sub 2}, decreased SO{sub 2} and NO{sub x} emissions, efficient way to utilize biofuels and recycled refuse fuels, low investment and operation costs, and utilization of the existing power plant capacity. Furthermore, only small modifications are required in the boiler, possible disturbances in the gasifier do not shut down the power plant. (author)

Sludge in the pulp and paper industry in Sweden, part II[Combustion of]; Slam fraan skogsindustrin, fas II

Energy Technology Data Exchange (ETDEWEB)

Gyllenhammar, Marianne; Herstad Svaerd, Solvie; Kjoerk, Anders; Larsson, Sara; Wennberg, Olle [S.E.P. Scandinavian Energy Project AB, Goeteborg (Sweden); Aamand, Lars-Erik [Chalmers Univ. of Technology, Goeteborg (Sweden); Eskilsson, David [Swedish National Testing and Research Inst., Boraas (Sweden)

2003-11-01

During part II of this research program combustible sludge from the pulp and paper industry has been studied in detail. 560,000 tonnes of sludge per year (calculated as dry sludge) are produced in Sweden. The energy potential in the produced sludge is about 2 TWh/year. Today 1 TWh/year is produced in the pulp and paper mill's own boilers. This means that additional energy can be utilized from this material. An objective of this program has been to decide whether or not there are sludge types which are favourable respectively difficult to combust. By mixing different sludge types, or other waste products, emissions and/or problems during combustion can be minimized. These possibilities have been studied thoroughly in this program. A lot of sludge samples have been studied in laboratory scale at SP and in full-scale at Chalmers 12 MW CFB boiler. As a complement to the practical tests S.E.P. has done research regarding different aspects of sludge as a fuel; for example handling of sludge and regional drying. The results of 40 sintering tests at SP showed that the sintering temperature during combustion of sludge in a fluidised bed, with silica sand as bed material, varied between <850 deg C and >1100 deg C. The evaluation showed that the alkali content in the ash had the largest influence on the sintering temperature. Other factors were less important. During the tests at Chalmers eleven different sludge samples have been combusted together with wood pellets. Initially there were problems with the feeding to the boiler for some of the sludge samples. When the fuel feeding problems were solved the combustion took place without any problems. When sludge is co-combusted together with a 'clean' base fuel such as wood pellets the sulphur-, nitrogen- and chloride contents in the sludge have a large impact on the emissions. The normal way to reduce sulphur dioxide but also hydrogen chloride is to add lime in different positions into and after the boiler. In

Combustion of a fuel mix containing animal waste, industry and household waste in FB-boilers; Foerbraenning av en braenslemix bestaaende av animaliskt avfall, industri- och hushaallsavfall i FB-pannor

Energy Technology Data Exchange (ETDEWEB)

Pettersson, Anita; Herstad Svaerd, Solvie; Moradian, Farzad

2012-11-01

-phosphates influenced to some extent the sand/ash flows were the largest change was an increase in the amount of phosphorus and calcium. In addition a decrease of the amount of lead was seen in all ash flows. The calcium-phosphates were stable during combustion and no reactions of phosphorus with other elements were detected. The results from the trials in this project show that co-combustion of biomal had the following positive effects on the boiler performance: 1. The bottom bed temperature decreased, but > 20 % biomal is needed to reach 750 deg C. 2. The risk for bed agglomeration was decreased. 3. The NO{sub x} emission was reduced at the same time as the addition of ammonia was reduced. 4. The deposition rate of the deposits collected on the test probe was reduced, thus no increased risk in deposit formation on the superheater tubes. The conclusion is that the boiler could be operated in a safe way with addition of biomal.

Combustion tests in a solid fuel boiler to clarify the emissions when co-firing refuse; Proveldning i fastbraenslepanna foer att kartlaegga emissioner vid inblandning av olika avfallsfraktioner

Energy Technology Data Exchange (ETDEWEB)

Blom, Elisabet; Lundborg, Rickard; Wrangensten, Lars

2002-04-01

}); The highest HCI emission, before the flue gas condensing plant, was noted for the reference fuel (approx. 245 Mg/nm{sup 3}); The highest SO{sub 2} emission, in the upper furnace, was also noted for the reference fuel (over 50 mg/nm{sup 3}). Levels after the condensing plant could not be measured. 25 % meat powder injection gave the highest NO{sub x}-emission (approx. 50 mg/MJ). The high heavy metal content in ash could not bee correlated to the content in the fuel fractions. The unburnt carbon content in bottom ash is remarkably lower for 25 % meat powder injection into reference fuel. The conclusion is that the operation parameters for the oiler are optimized for this specific fuel fraction and the amount injected. Tests with a fouling probe near the first superheater showed that at a temperature of 400 deg C 10% napkin waste gave most fouling. This is interesting as the lowest HCl-emission level was noted for napkins, maybe depending on that the chlorine is present in the depositions. The project results point in the direction that co-combustion of different refuse fractions will be possible within the existing environmental legislation and maybe also within the new EU directive 2000/76/EG. Although flue gas condensation is necessary to get acceptable emissions of HCl and SO{sub 2}. Further general research is thus needed and several R and D project areas are listed in the report. Deeper studies of the combustion process in furnace are important in future project.

Substitution of wastes for fuels and raw materials in high-temperature processes; Substitution von Brennstoffen und Rohstoffen durch Abfaelle in Hochtemperaturprozessen

Energy Technology Data Exchange (ETDEWEB)

Scholz, R. [Technische Univ. Clausthal, Clausthal-Zellerfeld (Germany). Inst. fuer Energieverfahrenstechnik; Beckmann, M. [Clausthaler Umwelttechnik-Institut GmbH (CUTEC), Clausthal-Zellerfeld (Germany)

1998-09-01

The physical recycling and energy conversion of wastes has for a long time been a topic of discussion. Some of the most interesting questions in this connection concern specific applications such as the co-combustion of sewage sludge in power plants, substitution of plastic wastes for primary fuels in burning processes in the cement industry etc. This paper also undertakes a comparative study of different applications, giving additional consideration to the state of the art in thermal waste treatment. Different processes can of course only be compared by taking the entirety of expenditures on additives and auxiliary energy into account and assuming equal side constraints for all processes. A further requirement is that the waste materials` specific properties that are relevant to the application in question have to be taken into account. This concerns in particular the effects of the substitution of waste-derived fuels (secondary fuels) for primary fuels on, for example, heat transfer conditions during the combustion process, flow conditions, and the resultant temperature distribution, transport of feedstock, and specific energy expenditure. Secondary fuels must be suited for substitution in various respects, e.g. in their material properties, and their combustion and thermal behaviour. The present paper deals in particular with the requirements on wastes as substitutes for primary fuels with regard to combustion and thermal behaviour. For this purpose it briefly discusses some important aspects of heat transfer in firing plants and industrial furnaces. An important criterion in assessing fuel substitution is the energy exchange ratio, which expresses value of the substitute fuel relative to that of the primary fuel and should be duly considered when making comparative studies. Focussing on aspects of process engineering the paper also deals exemplarily with the influence of fuel substitution on, e.g. furnace temperature, exhaust gas quantities etc. in clinker

Technological options for the management of biosolids.

Science.gov (United States)

Wang, Hailong; Brown, Sally L; Magesan, Guna N; Slade, Alison H; Quintern, Michael; Clinton, Peter W; Payn, Tim W

2008-06-01

Large quantities of biosolids (sewage sludge), which are produced from municipal wastewater treatment, are ever-increasing because of the commissioning of new treatment plants and continuous upgrades of the existing facilities. A large proportion of biosolids are currently landfilled. With increasing pressure from regulators and the general public, landfilling of biosolids is being phased out in many countries because of potential secondary pollution caused by leachate and the emission of methane, a potent greenhouse gas. Biosolids contain nutrients and energy that can be used beneficially. Significant efforts have been made recently to develop new technologies to manage biosolids and make useful products from them. In this paper, we provide a review of the technologies in biosolids management. A survey of literature was conducted. At present, the most common beneficial use of biosolids is agricultural land application because of inherent fertilizer values found in biosolids. Expansion of land application, however, may be limited in the future because of more stringent regulatory requirements and public concern about food chain contamination in some countries. Perceived as a green energy source, the combustion of biosolids has received renewed interest. Anaerobic digestion is generally a more effective method than incineration for energy recovery, and digested biosolids are suitable for further beneficial use through land application. Although conventional incineration systems for biosolid management generally consume more energy than they produce because of the high moisture content in the biosolids, it is expected that more combustion systems, either monocombustion or cocombustion, will be built to cope with the increasing quantity of biosolids. Under the increasingly popular low-carbon economy policy, biosolids may be recognized as a renewable fuel and be eligible for 'carbon credits'. Because ash can be used to manufacture construction materials, combustion can

Dioxin formation from waste incineration.

Science.gov (United States)

Shibamoto, Takayuki; Yasuhara, Akio; Katami, Takeo

2007-01-01

There has been great concern about dioxins-polychlorinated dibenzo dioxins (PCDDs), polychlorinated dibenzo furans (PCDFs), and polychlorinated biphenyls (PCBs)-causing contamination in the environment because the adverse effects of these chemicals on human health have been known for many years. Possible dioxin-contamination has received much attention recently not only by environmental scientists but also by the public, because dioxins are known to be formed during the combustion of industrial and domestic wastes and to escape into the environment via exhaust gases from incinerators. Consequently, there is a pressing need to investigate the formation mechanisms or reaction pathways of these chlorinated chemicals to be able to devise ways to reduce their environmental contamination. A well-controlled small-scale incinerator was used for the experiments in the core references of this review. These articles report the investigation of dioxin formation from the combustion of various waste-simulated samples, including different kinds of paper, various kinds of wood, fallen leaves, food samples, polyethylene (PE), polystyrene (PS), polyvinyl chloride (PVC), polyvinylidene chloride, polyethylene tetraphthalate (PET), and various kinds of plastic products. These samples were also incinerated with inorganic chlorides (NaCl, KCl, CuCI2, MgCl2, MnCl2, FeCl2, CoCl2, fly ash, and seawater) or organic chlorides (PVC, chlordane, and pentachlorophenol) to investigate the role of chlorine content and/or the presence of different metals in dioxin formation. Some samples, such as newspapers, were burned after they were impregnated with NaCl or PVC, as well as being cocombusted with chlorides. The roles of incineration conditions, including chamber temperatures, O2 concentrations, and CO concentrations, in dioxin formation were also investigated. Dioxins (PCDDs, PCDFs, and coplanar-PCBs) formed in the exhaust gases from a controlled small-scale incinerator, where experimental waste

Energy from waste. Vol. 2; Energie aus Abfall. Bd. 2

Energy Technology Data Exchange (ETDEWEB)

Thome-Kozmiensky, K.J.; Beckmann, M.

2007-07-01

In the book under consideration, the thermal treatment in waste incinerators, in industrial power stations and in coal-fired power stations is in the foreground. Possibilities of gasification are described. The chapter 'Developments of thermal waste treatment' consists of the following chapter: (a) Maximal size of waste incineration plants (Johannes J.E. Martin); (b) Trends and highlights of the thermal waste treatment in Europe (Martin Brunner); (c) Utilization of waste heat from Vienna waste incinerators for the operation of a district cooling grid - Effects on the primary energy efficiency of district heating and district cooling in Vienna (Franz Schindelar, Alexander Wallisch); (d) Evolutionary plant development based on experiences (Hans-Peter Buechner); (e) Effects of increased chlorine freights at the cocombustion of secondary fuels at the site of the brown coal fired power station Jaenschwalde (Frank Mielke, Andreas Sparmann, Sven Kappa); (f) Refuse-fueled power stations and waste incinerators - different plant technology? (Hendrik Seeger); (g) Generation of fuel gas from high calorific wastes (Udo Hellwig, Michael Beyer); (h) Strength testing of steam vessels with increased testing pressure (Wolfgang Rossmaier). The chapter 'Energy efficiency of waste incinerators' consists the following contributions: (a) Evaluation of energy efficiency in plants of thermal waste treatment; (b) Scientific-technical and juridical rationality - a contradiction? Comments to the judgement o the VGH Baden-Wuerttemberg according to waste incineration (Bodo A. Baars and Adolf Nottrodt); (c) Determination of the energy efficiency in plants of thermal waste incineration - To the difficulties of equivalent values and calculation of the calorific value (Michael Beckmann, Reinhard Scholz). The chapter 'Optimization of the plant technology' contains the following contributions: (a) Stay a while - Considerations according to the first tank of thermal waste