WorldWideScience

Sample records for coal combustion wastes

  1. Coal combustion waste management study

    International Nuclear Information System (INIS)

    1993-02-01

    Coal-fired generation accounted for almost 55 percent of the production of electricity in the United States in 1990. Coal combustion generates high volumes of ash and flue gas desulfurization (FGD) wastes, estimated at almost 90 million tons. The amount of ash and flue gas desulfurization wastes generated by coal-fired power plants is expected to increase as a result of future demand growth, and as more plants comply with Title IV of the 1990 Clean Air Act Amendments. Nationwide, on average, over 30 percent of coal combustion wastes is currently recycled for use in various applications; the remaining percentage is ultimately disposed in waste management units. There are a significant number of on-site and off-site waste management units that are utilized by the electric utility industry to store or dispose of coal combustion waste. Table ES-1 summarizes the number of disposal units and estimates of waste contained at these unites by disposal unit operating status (i.e, operating or retired). Further, ICF Resources estimates that up to 120 new or replacement units may need to be constructed to service existing and new coal capacity by the year 2000. The two primary types of waste management units used by the industry are landfills and surface impoundments. Utility wastes have been exempted by Congress from RCRA Subtitle C hazardous waste regulation since 1980. As a result of this exemption, coal combustion wastes are currently being regulated under Subtitle D of RCRA. As provided under Subtitle D, wastes not classified as hazardous under Subtitle C are subject to State regulation. At the same time Congress developed this exemption, also known as the ''Bevill Exclusion,'' it directed EPA to prepare a report on coal combustion wastes and make recommendations on how they should be managed

  2. Management of coal combustion wastes

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2014-02-01

    It has been estimated that 780 Mt of coal combustion products (CCPs) were produced worldwide in 2010. Only about 53.5% were utilised, the rest went to storage or disposal sites. Disposal of coal combustion waste (CCW) on-site at a power plant may involve decades-long accumulation of waste, with hundreds of thousands, if not millions, of tonnes of dry ash or wet ash slurry being stored. In December 2008, a coal combustion waste pond in Kingston, Tennessee, USA burst. Over 4 million cubic metres of ash sludge poured out, burying houses and rivers in tonnes of toxic waste. Clean-up is expected to continue into 2014 and will cost $1.2 billion. The incident drew worldwide attention to the risk of CCW disposal. This caused a number of countries to review CCW management methods and regulations. The report begins by outlining the physical and chemical characteristics of the different type of ashes generated in a coal-fired power plant. The amounts of CCPs produced and regulations on CCW management in selected countries have been compiled. The CCW disposal methods are then discussed. Finally, the potential environmental impacts and human health risks of CCW disposal, together with the methods used to prevent them, are reviewed.

  3. Coal combustion ashes: A radioactive Waste?

    International Nuclear Information System (INIS)

    Michetti, F.P.; Tocci, M.

    1992-01-01

    The radioactive substances naturally hold in fossil fuels, such as Uranium and Thorium, after the combustion, are subjected to an increase of concentration in the residual combustion products as flying ashes or as firebox ashes. A significant percentage of the waste should be classified as radioactive waste, while the political strategies seems to be setted to declassify it as non-radioactive waste. (Author)

  4. Experimental evaluation of main emissions during coal processing waste combustion.

    Science.gov (United States)

    Dmitrienko, Margarita A; Legros, Jean C; Strizhak, Pavel A

    2018-02-01

    The total volume of the coal processing wastes (filter cakes) produced by Russia, China, and India is as high as dozens of millions of tons per year. The concentrations of CO and CO 2 in the emissions from the combustion of filter cakes have been measured directly for the first time. They are the biggest volume of coal processing wastes. There have been many discussions about using these wastes as primary or secondary components of coal-water slurries (CWS) and coal-water slurries containing petrochemicals (CWSP). Boilers have already been operationally tested in Russia for the combustion of CWSP based on filter cakes. In this work, the concentrations of hazardous emissions have been measured at temperatures ranging from 500 to 1000°С. The produced CO and CO 2 concentrations are shown to be practically constant at high temperatures (over 900°С) for all the coal processing wastes under study. Experiments have shown the feasibility to lowering the combustion temperatures of coal processing wastes down to 750-850°С. This provides sustainable combustion and reduces the CO and CO 2 emissions 1.2-1.7 times. These relatively low temperatures ensure satisfactory environmental and energy performance of combustion. Using CWS and CWSP instead of conventional solid fuels significantly reduces NO x and SO x emissions but leaves CO and CO 2 emissions practically at the same level as coal powder combustion. Therefore, the environmentally friendly future (in terms of all the main atmospheric emissions: CO, CO 2 , NO x , and SO x ) of both CWS and CWSP technologies relies on low-temperature combustion. Copyright © 2017 Elsevier Ltd. All rights reserved.

  5. Geochemistry of coals, coal ashes and combustion wastes from coal-fired power stations

    International Nuclear Information System (INIS)

    Vassilev, S.V.; Vassileva, C.G.

    1997-01-01

    Contents, concentration trends, and modes of occurrence of 67 elements in coals, coal ashes, and combustion wastes at eleven Bulgarian thermoelectric power stations (TPS) were studied. A number of trace elements in coal and coal ash have concentrations greater than their respective worldwide average contents (Clarke values). Trace elements are concentrated mainly in the heavy accessory minerals and organic matter in coal. In decreasing order of significance, the trace elements in coal may occur as: element-organic compounds; impurities in the mineral matter; major components in the mineral matter; major and impurity components in the inorganic amorphous matter; and elements in the fluid constituent. A number of trace elements in the waste products, similar to coal ashes, exceed known Clarke contents. Trace elements are mainly enriched in non-magnetic, heavy and fine-grained fractions of fly ash. They are commonly present as impurities in the glass phases, and are included in the crystalline components. Their accessory crystalline phases, element-organic compounds, liquid and gas forms, are of subordinate importance. Some elements from the chalcophile, lithophile and siderophile groups may release into the atmosphere during coal burning. For others, the combustion process appears to be a powerful factor causing their relative enrichment in the fly ash and rarely in the bottom ash and slag. 65 refs., 1 fig., 11 tabs

  6. Coal Combustion Wastes Reuse in Low Energy Artificial Aggregates Manufacturing

    Science.gov (United States)

    Ferone, Claudio; Colangelo, Francesco; Messina, Francesco; Iucolano, Fabio; Liguori, Barbara; Cioffi, Raffaele

    2013-01-01

    Sustainable building material design relies mostly on energy saving processes, decrease of raw materials consumption, and increase of waste and by-products recycling. Natural and lightweight artificial aggregates production implies relevant environmental impact. This paper addresses both the issues of residues recycling and energy optimization. Particularly, three coal combustion wastes (Weathered Fly Ash, WFA; Wastewater Treatment Sludge, WTS; Desulfurization Device Sludge, DDS) supplied by the Italian electric utility company (ENEL) have been employed in the manufacture of cold bonded artificial aggregates. Previously, the residues have been characterized in terms of chemical and mineralogical compositions, water content, particle size distribution, and heavy metal release behavior. These wastes have been used in the mix design of binding systems with the only addition of lime. Finally, the artificial aggregates have been submitted to physical, mechanical, and leaching testing, revealing that they are potentially suitable for many civil engineering applications. PMID:28788372

  7. Coal Combustion Wastes Reuse in Low Energy Artificial Aggregates Manufacturing.

    Science.gov (United States)

    Ferone, Claudio; Colangelo, Francesco; Messina, Francesco; Iucolano, Fabio; Liguori, Barbara; Cioffi, Raffaele

    2013-10-31

    Sustainable building material design relies mostly on energy saving processes, decrease of raw materials consumption, and increase of waste and by-products recycling. Natural and lightweight artificial aggregates production implies relevant environmental impact. This paper addresses both the issues of residues recycling and energy optimization. Particularly, three coal combustion wastes (Weathered Fly Ash, WFA; Wastewater Treatment Sludge, WTS; Desulfurization Device Sludge, DDS) supplied by the Italian electric utility company (ENEL) have been employed in the manufacture of cold bonded artificial aggregates. Previously, the residues have been characterized in terms of chemical and mineralogical compositions, water content, particle size distribution, and heavy metal release behavior. These wastes have been used in the mix design of binding systems with the only addition of lime. Finally, the artificial aggregates have been submitted to physical, mechanical, and leaching testing, revealing that they are potentially suitable for many civil engineering applications.

  8. Coal Combustion Wastes Reuse in Low Energy Artificial Aggregates Manufacturing

    Directory of Open Access Journals (Sweden)

    Raffaele Cioffi

    2013-10-01

    Full Text Available Sustainable building material design relies mostly on energy saving processes, decrease of raw materials consumption, and increase of waste and by-products recycling. Natural and lightweight artificial aggregates production implies relevant environmental impact. This paper addresses both the issues of residues recycling and energy optimization. Particularly, three coal combustion wastes (Weathered Fly Ash, WFA; Wastewater Treatment Sludge, WTS; Desulfurization Device Sludge, DDS supplied by the Italian electric utility company (ENEL have been employed in the manufacture of cold bonded artificial aggregates. Previously, the residues have been characterized in terms of chemical and mineralogical compositions, water content, particle size distribution, and heavy metal release behavior. These wastes have been used in the mix design of binding systems with the only addition of lime. Finally, the artificial aggregates have been submitted to physical, mechanical, and leaching testing, revealing that they are potentially suitable for many civil engineering applications.

  9. Combustion Characteristics Of Agricultural Waste-Coal Char Blends

    International Nuclear Information System (INIS)

    Akpabio, I. O; Danbature W

    2002-01-01

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

  10. 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.

  11. Fluidized bed combustion of low-grade coal and wastes: Research and development

    Energy Technology Data Exchange (ETDEWEB)

    Borodulya, V.A.; Dikalenko, V.I.; Palchonok, G.I.; Vinogradov, L.M. [Academy of Sciences of Belarus, Minsk (Belarus). A.V. Luikov Heat and Mass Transfer Inst.; Dobkin, S.M.; Telegin, E.M. [Special Design Office, Brest (Belarus)

    1994-12-31

    Experimental studies were carried out to investigate devolatilization of fuel as single spherical particles of wood, hydrolytic lignin, leather sewage sludge and Belarussian brown coals in a fluidized bed of sand. It is found that the devolatilization process depends on moisture and ash contents in fuel and on the external heat and mass transfer rate. The char combustion occurs largely in the intermediate region. Kinetic parameters of the devolatilization and char combustion are obtained. A low-capacity fluidized bed boiler suitable for combustion of coal and different wastes is described.

  12. PAH emissions from coal combustion and waste incineration.

    Science.gov (United States)

    Hsu, Wei Ting; Liu, Mei Chen; Hung, Pao Chen; Chang, Shu Hao; Chang, Moo Been

    2016-11-15

    The characteristics of PAHs that are emitted by a municipal waste incinerator (MWI) and coal-fired power plant are examined via intensive sampling. Results of flue gas sampling reveal the potential for PAH formation within the selective catalytic reduction (SCR) system of a coal-fired power plant. In the large-scale MWI, the removal efficiency of PAHs achieved with the pilot-scaled catalytic filter (CF) exceeds that achieved by activated carbon injection with a bag filter (ACI+BF) owing to the effective destruction of gas-phase contaminants by a catalyst. A significantly lower PAH concentration (1640ng/g) was measured in fly ash from a CF module than from an ACI+BF system (5650ng/g). Replacing the ACI+BF system with CF technology would significantly reduce the discharge factor (including emission and fly ash) of PAHs from 251.6 to 77.8mg/ton-waste. The emission factors of PAHs that are obtained using ACI+BF and the CF system in the MWI are 8.05 and 7.13mg/ton, respectively. However, the emission factor of MWI is significantly higher than that of coal-fired power plant (1.56mg/ton). From the perspective of total environmental management to reduce PAH emissions, replacing the original ACI+BF process with a CF system is expected to reduce environmental impact thereof. Copyright © 2016 Elsevier B.V. All rights reserved.

  13. 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.)

  14. 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.

  15. Disposal of coal combustion wastes in the hydraulic backfill process

    Science.gov (United States)

    Pierzyna, Piotr

    2017-11-01

    This article presents the results of studies regarding the physical properties of selected combustion by-products (CCPs) currently produced in the energy production industry. These properties have been compared with the requirements of the technologies applied in the Polish underground mines. The article gives special consideration to the application of the products in the hydraulic backfill technology. The possibility of using bottom-ashes and slags was considered. The amount of CCPs disposed in Polish hard coal mines is approximately 1.1 million Mg and the tendency is decreasing. In the past two years, approximately 100-150 thousand Mg of CCPs was used in the hydraulic backfill technology. The percentage of the fraction smaller than 0.1 mm is determining for the possibility of using a given type of CCPs in the backfill material. This practically excludes the possibility of using any fly ashes in that technology. In slags from conventional boilers and bottom ashes from fluidized bed boilers the fraction below 0.1 mm constitutes 25% of the total at maximum, which allows for their use in the materials used in hydraulic backfill as a component comprising from 30% to 60%, respectively. Slags (10 01 01) are characterized by the lack of bonding properties, which, in case of open backfill systems that are exposed to atmospheric conditions, constitutes an advantage in comparison to bottom ashes (10 01 24), which in turn definitely exhibit bonding properties. The solution of the problem of using bottom ashes is their supply and application on a current basis.

  16. 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.

  17. Atmospheric fluidized-bed combustion (AFBC) co-firing of coal and hospital waste

    International Nuclear Information System (INIS)

    1993-02-01

    The proposed project involves co-firing of coal and medical waste (including infectious medical waste) in an atmospheric fluidized-bed combustor (AFBC) to safely dispose of medical waste and produce steam for hospital needs. Combustion at the design temperature and residence time (duration) in the AFBC has been proven to render infectious medical waste free of disease producing organisms. The project would be located at the Veterans Affairs (VA) Medical Center in Lebanon, Pennsylvania. The estimated cost of the proposed AFBC facility is nearly $4 million. It would be jointly funded by DOE, Veterans Affairs, and Donlee Technologies, Inc., of York, Pennsylvania, under a cooperative agreement between DOE and Donlee. Under the terms of this agreement, $3.708 million in cost-shared financial assistance would be jointly provided by DOE and the Veterans Affairs (50/50), with $278,000 provided by Donlee. The purposes of the proposed project are to: (1) provide the VA Medical Center and the Good Samaritan Hospital (GSH), also of Lebanon, Pennsylvania, with a solution for disposal of their medical waste; and (2) demonstrate that a new coal-burning technology can safely incinerate infectious medical waste, produce steam to meet hospital needs, and comply with environmental regulations

  18. Impact of coal combustion waste on the microbiology of a model aquifer

    International Nuclear Information System (INIS)

    Brunning, J.S.; Caldwell, D.E.; Lawrence, J.R.; Roberts, R.D.

    1994-01-01

    The effects of water infiltration into an alkaline coal combustion waste burial site on the chemical and microbiological aspects of a meso-scale (2,44 m diameter x 4.6 m, height, 65 tonne) model aquifer were analyzed. The spatial and temporal effects of the alkaline leachate on microbial activity, numbers and diversity were examined in the model and compared with uncontaminated control materials. Within the saturated zone below the waste there was a pH gradient from 12.4 at the water table, immediately below the waste, to 6.0 at 3.5 meters from the waste, and elevated levels of arsenic and strontium in the pore waters. Microtox testing of the contaminated pore waters indicated high toxicity (a gamma value of 1 at dilutions of 45 to 110 fold). The leachate contamination was associated with a reduction in bacterial ( 3 H) leucine incorporation from a high of 265 fmol g -1 h -1 in sediments below the contaminant plume to undetectable in the contaminated zone. In comparison, leucine incorporation rates in control column sediments were 899 fmol g -1 h -1 . Similar toxic effects were evident in reduced total direct and culturable counts of bacteria. Observations also indicated a reduction in microbial diversity and development of alkaline-tolerant microbial communities. These results indicated that any failure of confinement technologies at disposal sites would adversely affect both the chemistry and microbiology of the underlying saturated zone. 43 refs., 7 figs., 2 tabs

  19. Coal combustion waste management at landfills and surface impoundments 1994-2004.

    Energy Technology Data Exchange (ETDEWEB)

    Elcock, D.; Ranek, N. L.; Environmental Science Division

    2006-09-08

    On May 22, 2000, as required by Congress in its 1980 Amendments to the Resource Conservation and Recovery Act (RCRA), the U.S. Environmental Protection Agency (EPA) issued a Regulatory Determination on Wastes from the Combustion of Fossil Fuels. On the basis of information contained in its 1999 Report to Congress: Wastes from the Combustion of Fossil Fuels, the EPA concluded that coal combustion wastes (CCWs), also known as coal combustion by-products (CCBs), did not warrant regulation under Subtitle C of RCRA, and it retained the existing hazardous waste exemption for these materials under RCRA Section 3001(b)(3)(C). However, the EPA also determined that national regulations under Subtitle D of RCRA were warranted for CCWs that are disposed of in landfills or surface impoundments. The EPA made this determination in part on the basis of its findings that 'present disposal practices are such that, in 1995, these wastes were being managed in 40 percent to 70 percent of landfills and surface impoundments without reasonable controls in place, particularly in the area of groundwater monitoring; and while there have been substantive improvements in state regulatory programs, we have also identified gaps in State oversight' (EPA 2000). The 1999 Report to Congress (RTC), however, may not have reflected the changes in CCW disposal practices that occurred since the cutoff date (1995) of its database and subsequent developments. The U.S. Department of Energy (DOE) and the EPA discussed this issue and decided to conduct a joint DOE/EPA study to collect new information on the recent CCW management practices by the power industry. It was agreed that such information would provide a perspective on the chronological adoption of control measures in CCW units based on State regulations. A team of experts from the EPA, industry, and DOE (with support from Argonne National Laboratory) was established to develop a mutually acceptable approach for collecting and analyzing data

  20. Impact of coal combustion waste on the microbiology of a model aquifer

    Energy Technology Data Exchange (ETDEWEB)

    Brunning, J.S.; Caldwell, D.E.; Lawrence, J.R.; Roberts, R.D. (University of Saskatchewan, Saskatoon, SK (Canada). Dept. of Applied Microbiology and Food Science)

    1994-03-01

    The effects of water infiltration into an alkaline coal combustion waste burial site on the chemical and microbiological aspects of a meso-scale (2,44 m diameter x 4.6 m, height, 65 tonne) model aquifer were analyzed. The spatial and temporal effects of the alkaline leachate on microbial activity, numbers and diversity were examined in the model and compared with uncontaminated control materials. Within the saturated zone below the waste there was a pH gradient from 12.4 at the water table, immediately below the waste, to 6.0 at 3.5 meters from the waste, and elevated levels of arsenic and strontium in the pore waters. Microtox testing of the contaminated pore waters indicated high toxicity (a gamma value of 1 at dilutions of 45 to 110 fold). The leachate contamination was associated with a reduction in bacterial ([sup 3]H) leucine incorporation from a high of 265 fmol g[sup -1]h[sup -1] in sediments below the contaminant plume to undetectable in the contaminated zone. In comparison, leucine incorporation rates in control column sediments were 899 fmol g[sup -1]h[sup -1]. Similar toxic effects were evident in reduced total direct and culturable counts of bacteria. Observations also indicated a reduction in microbial diversity and development of alkaline-tolerant microbial communities. These results indicated that any failure of confinement technologies at disposal sites would adversely affect both the chemistry and microbiology of the underlying saturated zone. 43 refs., 7 figs., 2 tabs.

  1. Responsiveness of the hypothalamo-pituitary-interrenal axis in an amphibian (Bufo terrestris) exposed to coal combustion wastes

    International Nuclear Information System (INIS)

    Hopkins, W.A.; Mendonca, M.T.; Congdon, J.D.

    1999-01-01

    To assess the responsiveness of the interrenal axis to stress, we injected toads exposed to coal combustion wastes and toads from an unpolluted reference site with adrenocorticotropic hormone (ACTH), as well as the vehicle alone (saline). Initial circulating levels of corticosterone in toads captured at the polluted area were significantly higher than levels in toads from the reference site. Corticosterone levels in toads from the polluted site remained high even after 2 weeks of laboratory acclimation and injection with saline. The results may suggest disruption of hepatic enzymes responsible for the metabolic clearance of steroid hormones. Injection of toads from the polluted site with ACTH had no effect on plasma corticosterone levels, whereas a similar treatment of toads from the reference site stimulated a marked increase in corticosterone. Our study provides evidence that toads exposed to coal combustion wastes may be less efficient at responding to additional environmental stressors. (Copyright (c) 1999 Elsevier Science B.V., Amsterdam. All rights reserved.)

  2. Characterization and quantification of corticosteroid-binding globulin in a southern toad, Bufo terrestris, exposed to coal-combustion-waste

    Energy Technology Data Exchange (ETDEWEB)

    Ward, C.K.; Fontes, C.; Breuner, C.W.; Mendonca, M.T. [Auburn University, Auburn, AL (USA). Dept. of Biological Science

    2007-05-15

    Corticosteroid-binding globulin (CBG) is a plasma protein that binds corticosterone and may regulate access of hormone to tissues. The role of CBG during a stress response is not clear. In this study, southern toads, Bufo terrestris, were exposed to a chronic pollutant (coal-combustion-waste), to determine changes in CBG and free corticosterone levels. Since toads exposed to chronic pollutants in previous studies did not exhibit the predicted changes in metabolic rate and mass, but did experience a significant elevation in total corticosterone, we hypothesized that CBG would likewise increase and thus, mitigate the effects of a chronic (i.e. 2 months) pollutant stressor. To conduct this study, we first characterized the properties of CBG in southern toads. After characterization, we monitored the changes in CBG, total corticosterone, and free corticosterone in male toads that were exposed to either coal-combustion-waste or control conditions. CBG increased in all groups throughout the experiment. Total corticosterone, on the other hand, was only significantly elevated at four weeks of exposure to coal-combustion-waste. The increase in CBG did not parallel the increase in total corticosterone; as a result, free corticosterone levels were not buffered by CBG, but showed a peak at four weeks similar to total corticosterone. This finding indicates that, in this species, CBG may not provide a protective mechanism during long-term pollution exposure.

  3. Application of wasted sea-shell to desulfurizer in fluidized bed coal combustion

    Energy Technology Data Exchange (ETDEWEB)

    Naruse, Ichiro; Saito, Katsuhiro; Murakami, Takahiro

    1999-07-01

    Almost all wasted seashells consist of CaCo{sub 3}, and are similar to limestone. It would be proposed that the seashell could be applied as a desulfurizer. In this study, desulfurization characteristics of the seashell are fundamentally studied by using a thermobalance and a bubbling fluidized coal combustor with comparing the results obtained by limestone as a reference. Under the constant calcination temperature, the desulfurization efficiency for the seashells attains more than about 70% after the desulfurization period of 30 h. For the limestones, on the other hand, the desulfurization efficiency becomes only 38%. Under practical conditions of fluidized bed coal combustion, the desulfurization efficiency for the seashells also indicates higher value than that for the limestones. The desulfurization efficiency depends on the pore size distribution of CaO rather than its specific surface area. The mean pore size of the calcined seashell is about 10 times as large as that of the calcined limestones. from Scanning Electro-Microscope (SEM) photos of the surface of CaCO{sub 3}, CaO and the sulfurized particles of the seashells the large pores can be observed. In measuring cross-sectional distribution of sulfur inside the particles by using an Energy Dispersed X-ray (EDX) system, the sulfur in the sulfurized particle of limestone is only trapped near the particle surface. For the seashells, whereas, the sulfur is distributed over the whole body of particle. Desulfurization efficiency for the limestone, into which some alkali metal compounds are added, increases with increasing the concentration of alkali metal compounds added. In order of increasing effect the key elemental species to enhance the desulfurization activities are Cl, Na and K. Alkali metal compounds can enhance the desulfurization activities, due to solution of CaO in molten NaCl. This is one of the reasons why the desulfurization efficiency for the seashells improves.

  4. Plant growth response in experimental soilless mixes prepared from coal combustion products and organic waste materials

    Energy Technology Data Exchange (ETDEWEB)

    Bardhan, S.; Watson, M.; Dick, W.A. [Ohio State University, Wooster, OH (United States)

    2008-07-15

    Large quantities of organic materials such as animal manures, yard trimmings, and biosolids are produced each year. Beneficial use options for them are often limited, and composting has been proposed as a way to better manage these organic materials. Similarly, burning of coal created 125 million tons of coal combustion products (CCP) in the United States in 2006. An estimated 53 million tons of CCP were reused, whereas the remainder was deposited in landfills. By combining CCP and composted organic materials (COM), we were able to create soilless plant growth mixes with physicochemical conditions that can support excellent plant growth. An additional benefit is the conservation of natural raw materials, such as peat, which is generally used for making soilless mixes. Experimental mixes were formulated by combining CCP and COM at ratios ranging from 2:8 to 8:2 (vol/vol), respectively. Water content at saturation for the created mixes was 63% to 72%, whereas for the commercial control, it was 77%. pH values for the best performing mixes ranged between 5.9 and 6.8. Electrical conductivity and concentrations of required plant nutrient were also within plant growth recommendations for container media. Significantly (P < 0.0001) higher plant biomass growth (7%-130%) was observed in the experimental mixes compared with a commercial mix. No additional fertilizers were provided during the experiment, and reduced fertilization costs can thus accrue as an added benefit to the grower. In summary, combining CCP and COM, derived from source materials often viewed as wastes, can create highly productive plant growth mixes.

  5. Coal combustion technology in China

    International Nuclear Information System (INIS)

    Huang, Z.X.

    1994-01-01

    Coal is the most important energy source in China, the environmental pollution problem derived from coal burning is rather serious in China. The present author discusses coal burning technologies both in boilers and industrial furnaces and their relations with environmental protection problems in China. The technological situations of Circulating Fluidized Bed Coal Combustor, Pulverized Coal Combustor with Aerodynamic Flame Holder and Coal Water Slurry Combustion have been discussed here as some of the interesting problems in China only. (author). 3 refs

  6. 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.

  7. 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...

  8. 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.

  9. Elevated standard metabolic rate in a freshwater shrimp (Palaeomonetes paludosus) exposed to trace element-rich coal combustion waste

    Energy Technology Data Exchange (ETDEWEB)

    Rowe, C.L. [University of Georgia, Aiken, SC (United States). Savannah River Ecology Lab.

    1998-12-01

    A transplant experiment was conducted to determine whether standard metabolic rate (SMR) of a freshwater shrimp (Palaeomonetes paludosus) would be affected by exposure to trace element-enriched coal combustion waste (coal ash). Shrimp were transplanted into replicate cages in a coal ash-polluted site and a reference site for 8 months. The coal ash-polluted site was characterized by elevated sediment concentrations of As, Cd, Cr, Cu, Ni, Pb and Se compared to sediments in the reference site. After 8 months in the study sites, shrimp in the polluted site appeared to have accumulated As, Cd and Se from the habitat, but there were on differences in survival between the study sites. However, mean SMR of shrimp (measured as O{sub 2} consumption at rest) held in the polluted site was 51% higher than mean SMR of shrimp held in the reference site. The elevation in SMR indicates that the energetic costs of maintenance are greater for shrimp chronically exposed to the coal-ash polluted enviorment than shrimp in the reference site. It is likely, therefore, that other physiological or behavioral processes may be modified in the pollution-exposed individuals to compensate for the increased energy demands for maintenance. Recent studies have reported similar elevations in SMR in an amphibian and a reptile chronically exposed to coal ash. Analogous physiological responses in such taxonomically diverse animals (a crustacean, an amphibian, and a reptile) indicate that elevated SMR may be a general response by many types of organisms exposed to the mixture of trace elements characteristic of coal ash. The relationships among pollution-induced elevations in maintenance expenditures, long-term health of individuals, and population-level parameters require further attention. 19 refs., 1 fig., 1 tab.

  10. Interactive effects of maternal and environmental exposure to coal combustion wastes decrease survival of larval southern toads (Bufo terrestris)

    International Nuclear Information System (INIS)

    Metts, Brian S.; Buhlmann, Kurt A.; Scott, David E.; Tuberville, Tracey D.; Hopkins, William A.

    2012-01-01

    We conducted a mesocosm study to assess the individual and interactive effects of previous maternal exposure and larval exposure to trace element-laden sediments on southern toads (Bufo terrestris). Previous maternal exposure to coal combustion wastes (CCW) reduced larval survival to metamorphosis up to 57% compared to larvae of unexposed females. Larvae reared on CCW accumulated significant concentrations of trace elements resulting in extended larval periods, reduced growth rates, and reduced mass at metamorphosis. However, the effects were dependent on age of sediments, suggesting the effects of contaminants from CCW may be partially ameliorated over time through the reduced bioavailability of trace elements in aged CCW. Most importantly, maternal exposure to contaminants coupled with larval exposure to fresh CCW interacted to reduce survival to metamorphosis by 85% compared to reference conditions. Our study yields further evidence that disposal of CCW in aquatic basins potentially creates ecological traps for some amphibian populations. - Highlights: ► The interaction of maternal exposure and larval exposure to CCW reduced survival. ► Previous maternal exposure to CCW had a latent effect on survival to metamorphosis. ► Larval southern toads exposed to CCW experienced prolonged larval periods. ► Larval southern toads exposed to CCW had reduced growth rates. ► Larval southern toads exposed to CCW had reduced mass at metamorphosis. - Maternal and environmental exposure to coal combustion wastes interact to decrease survival in larval amphibians.

  11. 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)

  12. 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 ...

  13. A comparison of circulating fluidised bed combustion and gasification power plant technologies for processing mixtures of coal, biomass and plastic waste

    International Nuclear Information System (INIS)

    McIlveen-Wright, D.R.; Huang, Y.; McMullan, J.T.; Pinto, F.; Franco, C.; Gulyurtlu, I.; Armesto, L.; Cabanillas, A.; Caballero, M.A.; Aznar, M.P.

    2006-01-01

    Environmental regulations concerning emission limitations from the use of fossil fuels in large combustion plants have stimulated interest in biomass for electricity generation. The main objective of the present study was to examine the technical and economic viability of using combustion and gasification of coal mixed with biomass and plastic wastes, with the aim of developing an environmentally acceptable process to decrease their amounts in the waste stream through energy recovery. Mixtures of a high ash coal with biomass and/or plastic using fluidised bed technologies (combustion and gasification) were considered. Experiments were carried out in laboratory and pilot plant fluidised bed systems on the combustion and air/catalyst and air/steam gasification of these feedstocks and the data obtained were used in the techno-economic analyses. The experimental results were used in simulations of medium to large-scale circulating fluidised bed (CFB) power generation plants. Techno-economic analysis of the modelled CFB combustion systems showed efficiencies of around 40.5% (and around 46.5% for the modelled CFB gasification systems) when fuelled solely by coal, which were only minimally affected by co-firing with up to 20% biomass and/or wastes. Specific investments were found to be around $2150/kWe to $2400/kWe ($1350/kWe to $1450/kWe) and break-even electricity selling prices to be around $68/MWh to $78/MWh ($49/MWh to $54/MWh). Their emissions were found to be within the emission limit values of the large combustion plant directive. Fluidised bed technologies were found to be very suitable for co-firing coal and biomass and/or plastic waste and to offer good options for the replacement of obsolete or polluting power plants. (author)

  14. Leaching of coal solid waste; Lixiviacion de Residuos de Combustion de Carbon

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2000-07-01

    Combustion process to generate electrical energy in Thermal power Stations causes a big volume of solid wastes. Their store and removal has to be check for possible risks in the Environment. In this study, ashes and slags from eleven Spanish Thermal power Station has been selected. Physical chemical assays have been developed for determining twenty four parameters by; ionic chromatography, atomic absorption spectrophotometry liquid chromatography. (HPLC): UV and selective electrodes, selective electrodes espectrophotometry. Moreover, six biological tests have been realized: Bioluminescence with Photobacterium phosphoreum, Daphnia magna assay. Inhibition on Algae, Inhibition of respiration of Activated Sludges, Acute Toxicity on Fish and Earth-worm Toxicity tests. Samples treatment has been carrying out by two leaching methods: 1 o EP and DIN 38414-4 No toxic level has been found for physical-chemical parameters. The CE50 values of biological tests have allowed to stablish organisms sensibilities to waste samples, differences between ashes and slags and relationship between the carbon type and his effects on the biological organisms. (Author)

  15. 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.

  16. Modeling the impact of chlorine emissions from coal combustion and prescribed waste incineration on tropospheric ozone formation in China

    Science.gov (United States)

    Liu, Yiming; Fan, Qi; Chen, Xiaoyang; Zhao, Jun; Ling, Zhenhao; Hong, Yingying; Li, Weibiao; Chen, Xunlai; Wang, Mingjie; Wei, Xiaolin

    2018-02-01

    Chlorine radicals can enhance atmospheric oxidation, which potentially increases tropospheric ozone concentration. However, few studies have been done to quantify the impact of chlorine emissions on ozone formation in China due to the lack of a chlorine emission inventory used in air quality models with sufficient resolution. In this study, the Anthropogenic Chlorine Emissions Inventory for China (ACEIC) was developed for the first time, including emissions of hydrogen chloride (HCl) and molecular chlorine (Cl2) from coal combustion and prescribed waste incineration (waste incineration plant). The HCl and Cl2 emissions from coal combustion in China in 2012 were estimated to be 232.9 and 9.4 Gg, respectively, while HCl emission from prescribed waste incineration was estimated to be 2.9 Gg. Spatially the highest emissions of HCl and Cl2 were found in the North China Plain, the Yangtze River Delta, and the Sichuan Basin. Air quality model simulations with the Community Multiscale Air Quality (CMAQ) modeling system were performed for November 2011, and the modeling results derived with and without chlorine emissions were compared. The magnitude of the simulated HCl, Cl2 and ClNO2 agreed reasonably with the observation when anthropogenic chlorine emissions were included in the model. The inclusion of the ACEIC increased the concentration of fine particulate Cl-, leading to enhanced heterogeneous reactions between Cl- and N2O5, which resulted in the higher production of ClNO2. Photolysis of ClNO2 and Cl2 in the morning and the reaction of HCl with OH in the afternoon produced chlorine radicals which accelerated tropospheric oxidation. When anthropogenic chlorine emissions were included in the model, the monthly mean concentrations of fine particulate Cl-, daily maximum 1 h ClNO2, and Cl radicals were estimated to increase by up to about 2.0 µg m-3, 773 pptv, and 1.5 × 103 molecule cm-3 in China, respectively. Meanwhile, the monthly mean daily maximum 8 h O3

  17. Modeling the impact of chlorine emissions from coal combustion and prescribed waste incineration on tropospheric ozone formation in China

    Directory of Open Access Journals (Sweden)

    Y. Liu

    2018-02-01

    Full Text Available Chlorine radicals can enhance atmospheric oxidation, which potentially increases tropospheric ozone concentration. However, few studies have been done to quantify the impact of chlorine emissions on ozone formation in China due to the lack of a chlorine emission inventory used in air quality models with sufficient resolution. In this study, the Anthropogenic Chlorine Emissions Inventory for China (ACEIC was developed for the first time, including emissions of hydrogen chloride (HCl and molecular chlorine (Cl2 from coal combustion and prescribed waste incineration (waste incineration plant. The HCl and Cl2 emissions from coal combustion in China in 2012 were estimated to be 232.9 and 9.4 Gg, respectively, while HCl emission from prescribed waste incineration was estimated to be 2.9 Gg. Spatially the highest emissions of HCl and Cl2 were found in the North China Plain, the Yangtze River Delta, and the Sichuan Basin. Air quality model simulations with the Community Multiscale Air Quality (CMAQ modeling system were performed for November 2011, and the modeling results derived with and without chlorine emissions were compared. The magnitude of the simulated HCl, Cl2 and ClNO2 agreed reasonably with the observation when anthropogenic chlorine emissions were included in the model. The inclusion of the ACEIC increased the concentration of fine particulate Cl−, leading to enhanced heterogeneous reactions between Cl− and N2O5, which resulted in the higher production of ClNO2. Photolysis of ClNO2 and Cl2 in the morning and the reaction of HCl with OH in the afternoon produced chlorine radicals which accelerated tropospheric oxidation. When anthropogenic chlorine emissions were included in the model, the monthly mean concentrations of fine particulate Cl−, daily maximum 1 h ClNO2, and Cl radicals were estimated to increase by up to about 2.0 µg m−3, 773 pptv, and 1.5  ×  103 molecule cm−3 in China, respectively. Meanwhile

  18. Oxy-coal Combustion Studies

    Energy Technology Data Exchange (ETDEWEB)

    Wendt, J. [Univ. of Utah, Salt Lake City, UT (United States); Eddings, E. [Univ. of Utah, Salt Lake City, UT (United States); Lighty, J. [Univ. of Utah, Salt Lake City, UT (United States); Ring, T. [Univ. of Utah, Salt Lake City, UT (United States); Smith, P. [Univ. of Utah, Salt Lake City, UT (United States); Thornock, J. [Univ. of Utah, Salt Lake City, UT (United States); Y Jia, W. Morris [Univ. of Utah, Salt Lake City, UT (United States); Pedel, J. [Univ. of Utah, Salt Lake City, UT (United States); Rezeai, D. [Univ. of Utah, Salt Lake City, UT (United States); Wang, L. [Univ. of Utah, Salt Lake City, UT (United States); Zhang, J. [Univ. of Utah, Salt Lake City, UT (United States); Kelly, K. [Univ. of Utah, Salt Lake City, UT (United States)

    2012-01-06

    The objective of this project is to move toward the development of a predictive capability with quantified uncertainty bounds for pilot-scale, single-burner, oxy-coal operation. This validation research brings together multi-scale experimental measurements and computer simulations. The combination of simulation development and validation experiments is designed to lead to predictive tools for the performance of existing air fired pulverized coal boilers that have been retrofitted to various oxy-firing configurations. In addition, this report also describes novel research results related to oxy-combustion in circulating fluidized beds. For pulverized coal combustion configurations, particular attention is focused on the effect of oxy-firing on ignition and coal-flame stability, and on the subsequent partitioning mechanisms of the ash aerosol.

  19. Soil amendments promote vegetation establishment and control acidity in coal combustion waste

    Science.gov (United States)

    R.M. Danker; D.C. Adriano; Bon-Jun Koo; C.D. Barton

    2003-01-01

    The effects of adding various soil amendments and a pyrite oxidation inhibitor to aid in the establishment of vegetation and to reduce acid drainage (AD) from coal fly ash and coal reject (FA + CR*) were assessed in an outdoor mesocosm study. Preliminary greenhouse experiments and field observations at the U.S. Department of Energy's Savannah River Site (SRS)...

  20. Study of mechanically activated coal combustion

    Directory of Open Access Journals (Sweden)

    Burdukov Anatolij P.

    2009-01-01

    Full Text Available Combustion and air gasification of mechanically activated micro-ground coals in the flux have been studied. Influence of mechanically activated methods at coals grinding on their chemical activeness at combustion and gasification has been determined. Intense mechanical activation of coals increases their chemical activeness that enables development of new highly boosted processing methods for coals with various levels of metamorphism.

  1. 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.

  2. The complex using of coals of Ekibastuz coal basin and wastes of their development

    International Nuclear Information System (INIS)

    Gorlov, E.G.; Kost, L.A.; Lebedeva, L.N.; Shpirt, M.Ya.

    2013-01-01

    Present article is devoted to main directions of complex using of coals of Ekibastuz coal basin and wastes of their development. It was found that gasification of Ekibastuz coals is the perspective way of their using. It is defined that coal gasification could solve the ecological problems which arise at industrial combustion of coal. Therefore, the thermodynamic and experimental researches were conducted.

  3. 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.

  4. 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)

  5. 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.

  6. Coal combustion products: trash or treasure?

    Energy Technology Data Exchange (ETDEWEB)

    Hansen, T.

    2006-07-15

    Coal combustion by-products can be a valuable resource to various industries. The American Coal Ash Association (ACAA) collects data on production and uses of coal combustion products (CCPs). 122.5 million tons of CCPs were produced in 2004. The article discusses the results of the ACCA's 2004 survey. Fly ash is predominantly used as a substitute for Portland cement; bottom ash for structural fill, embankments and paved road cases. Synthetic gypsum from the FGD process is commonly used in wallboard. Plant owners are only likely to have a buyer for a portion of their CCPs. Although sale of hot water (from Antelope Valley Station) from condensers for use in a fish farm to raise tilapia proved unviable, the Great Plains Synfuels Plant which manufactures natural gas from lignite produces a wide range of products including anhydrous ammonia, phenol, krypton, carbon dioxide (for enhanced oil recovery), tar oils and liquid nitrogen. ACCA's goal is to educate people about CCPs and how to make them into useful products, and market them, in order to reduce waste disposal and enhance revenue. The article lists members of the ACCA. 2 photos., 1 tab.

  7. 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.

  8. Coal Combustion Products Extension Program

    Energy Technology Data Exchange (ETDEWEB)

    Tarunjit S. Butalia; William E. Wolfe

    2006-01-11

    This final project report presents the activities and accomplishments of the ''Coal Combustion Products Extension Program'' conducted at The Ohio State University from August 1, 2000 to June 30, 2005 to advance the beneficial uses of coal combustion products (CCPs) in highway and construction, mine reclamation, agricultural, and manufacturing sectors. The objective of this technology transfer/research program at The Ohio State University was to promote the increased use of Ohio CCPs (fly ash, FGD material, bottom ash, and boiler slag) in applications that are technically sound, environmentally benign, and commercially competitive. The project objective was accomplished by housing the CCP Extension Program within The Ohio State University College of Engineering with support from the university Extension Service and The Ohio State University Research Foundation. Dr. Tarunjit S. Butalia, an internationally reputed CCP expert and registered professional engineer, was the program coordinator. The program coordinator acted as liaison among CCP stakeholders in the state, produced information sheets, provided expertise in the field to those who desired it, sponsored and co-sponsored seminars, meetings, and speaking at these events, and generally worked to promote knowledge about the productive and proper application of CCPs as useful raw materials. The major accomplishments of the program were: (1) Increase in FGD material utilization rate from 8% in 1997 to more than 20% in 2005, and an increase in overall CCP utilization rate of 21% in 1997 to just under 30% in 2005 for the State of Ohio. (2) Recognition as a ''voice of trust'' among Ohio and national CCP stakeholders (particularly regulatory agencies). (3) Establishment of a national and international reputation, especially for the use of FGD materials and fly ash in construction applications. It is recommended that to increase Ohio's CCP utilization rate from 30% in 2005 to

  9. Coal slurry combustion and technology. Volume 2

    Energy Technology Data Exchange (ETDEWEB)

    1983-01-01

    Volume II contains papers presented at the following sessions of the Coal Slurry Combustion and Technology Symposium: (1) bench-scale testing; (2) pilot testing; (3) combustion; and (4) rheology and characterization. Thirty-three papers have been processed for inclusion in the Energy Data Base. (ATT)

  10. Systems and methods of storing combustion waste products

    Science.gov (United States)

    Chen, Shen-En; Wang, Peng; Miao, Xiexing; Feng, Qiyan; Zhu, Qianlin

    2016-04-12

    In one aspect, methods of storing one or more combustion waste products are described herein. Combustion waste products stored by a method described herein can include solid combustion waste products such as coal ash and/or gaseous combustion products such as carbon dioxide. In some embodiments, a method of storing carbon dioxide comprises providing a carbon dioxide storage medium comprising porous concrete having a macroporous and microporous pore structure and flowing carbon dioxide captured from a combustion flue gas source into the pore structure of the porous concrete.

  11. 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.

  12. 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)

  13. Combustion chamber for solid and liquid waste

    Energy Technology Data Exchange (ETDEWEB)

    Vcelak, L.; Kocica, J.; Trnobransky, K.; Hrubes, J. (VSCHT, Prague (Czechoslovakia))

    1989-04-01

    Describes combustion chamber incorporated in a new boiler manufactured by Elitex of Kdyne to burn waste products and occasionally liquid and solid waste from neighboring industries. It can handle all kinds of solids (paper, plastics, textiles, rubber, household waste) and liquids (volatile and non-volatile, zinc, chromium, etc.) and uses coal as a fuel additive. Its heat output is 3 MW, it can burn 1220 kg/h of coal (without waste, calorific value 11.76 MJ/kg) or 500 kg/h of coal (as fuel additive, calorific value 11.76 MJ/kg) or 285 kg/h of solid waste (calorific value 20.8 MJ/kg). Efficiency is 75%, capacity is 103 m{sup 3} and flame temperature is 1,310 C. Individual components are designed for manufacture in small engineering workshops with basic equipment. A disk absorber with alkaline filling is fitted for removal of harmful substances arising when PVC or tires are combusted.

  14. Environmental indicators of the combustion of prospective coal water slurry containing petrochemicals.

    Science.gov (United States)

    Dmitrienko, Margarita A; Nyashina, Galina S; Strizhak, Pavel A

    2017-09-15

    Negative environmental impact of coal combustion has been known to humankind for a fairly long time. Sulfur and nitrogen oxides are considered the most dangerous anthropogenic emissions. A possible solution to this problem is replacing coal dust combustion with that of coal water slurry containing petrochemicals (CWSP). Coal processing wastes and used combustible liquids (oils, sludge, resins) are promising in terms of their economic and energy yield characteristics. However, no research has yet been conducted on the environmental indicators of fuels based on CWSP. The present work contains the findings of the research of CO, CO2, NOx, SOx emissions from the combustion of coals and CWSPs produced from coal processing waste (filter cakes). It is demonstrated for the first time that the concentrations of dangerous emissions from the combustion of CWSPs (carbon oxide and dioxide), even when combustible heavy liquid fractions are added, are not worse than those of coal. As for the concentration of sulfur and nitrogen oxides, it is significantly lower for CWSPs combustion as compared to coals. The presented research findings illustrate the prospects of the wide use of CWSPs as a fuel that is cheap and beneficial, in terms of both energy output and ecology, as compared to coal. Copyright © 2017 Elsevier B.V. All rights reserved.

  15. Influence of Coal Quality on Combustion Performance

    DEFF Research Database (Denmark)

    Lans, Robert Pieter Van Der; Glarborg, Peter; Dam-Johansen, Kim

    1998-01-01

    mixing pattern on NO formation under these conditions. Emissions from the opposed fired plant with all combustion air introduced through the burners could only be qualitatively reproduced by the pilot furnace. Under single stage conditions the test rig provided higher NO levels. Carbon in ash levels did...... not show any correlation between the coals and the furnaces. An engineering, mathematical model has been developed describing radiation heat transfer and coal combustion in full scale furnaces. The model has been validated against measured temperatures and the amount of carbon in fly ash. The model...

  16. Solid waste combustion for alpha waste incineration

    International Nuclear Information System (INIS)

    Orloff, D.I.

    1981-02-01

    Radioactive waste incinerator development at the Savannah River Laboratory has been augmented by fundamental combustion studies at the University of South Carolina. The objective was to measure and model pyrolysis and combustion rates of typical Savannah River Plant waste materials as a function of incinerator operating conditions. The analytical models developed in this work have been incorporated into a waste burning transient code. The code predicts maximum air requirement and heat energy release as a function of waste type, package size, combustion chamber size, and temperature. Historically, relationships have been determined by direct experiments that did not allow an engineering basis for predicting combustion rates in untested incinerators. The computed combustion rates and burning times agree with measured values in the Savannah River Laboratory pilot (1 lb/hr) and full-scale (12 lb/hr) alpha incinerators for a wide variety of typical waste materials

  17. Coal combustion aerothermochemistry research. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Witte, A.B.; Gat, N.; Denison, M.R.; Cohen, L.M.

    1980-12-15

    On the basis of extensive aerothermochemistry analyses, laboratory investigations, and combustor tests, significant headway has been made toward improving the understanding of combustion phenomena and scaling of high swirl pulverized coal combustors. A special attempt has been made to address the gap between scientific data available on combustion and hardware design and scaling needs. Both experimental and theoretical investigations were conducted to improve the predictive capability of combustor scaling laws. The scaling laws derived apply to volume and wall burning of pulverized coal in a slagging high-swirl combustor. They incorporate the findings of this investigation as follows: laser pyrolysis of coal at 10/sup 6/ K/sec and 2500K; effect of coal particle shape on aerodynamic drag and combustion; effect of swirl on heat transfer; coal burnout and slag capture for 20 MW/sub T/ combustor tests for fine and coarse coals; burning particle trajectories and slag capture; particle size and aerodynamic size; volatilization extent and burnout fraction; and preheat level. As a result of this work, the following has been gained: an increased understanding of basic burning mechanisms in high-swirl combustors and an improved model for predicting combustor performance which is intended to impact hardware design and scaling in the near term.

  18. Co-combustion of Fossil Fuels and Waste

    DEFF Research Database (Denmark)

    Wu, Hao

    The Ph.D. thesis deals with the alternative and high efficiency methods of using waste-derived fuels in heat and power production. The focus is on the following subjects: 1) co-combustion of coal and solid recovered fuel (SRF) under pulverized fuel combustion conditions; 2) dust-firing of straw...

  19. Fluidized bed and pulverized coal combustion residues for secondary pavements

    International Nuclear Information System (INIS)

    Ghafoori, N.; Diawara, H.; Wang, L.

    2009-01-01

    The United States produced nearly 125 million tons of coal combustion products in 2006. These by-products include fly ash, flue gas desulphurization materials, bottom ash, boiler slag, and other power plant by-products. The expense associated with waste disposal, lack of disposal sites, and significant environmental damage linked with the disposal of coal combustion residues have encouraged innovative utilization strategies such as the fluidized bed combustion (FBC) unit. This paper presented the results of a laboratory investigation that examined the properties of composites developed with different proportions of pre-conditioned FBC spent bed, pulverized coal combustion fly ash, natural fine aggregate, and Portland cement. The purpose of the study was to examine the extent to which the by-product composites could replace currently used materials in secondary roads. The paper presented the research objectives and experimental programs, including matrix constituent and proportions; mixture proportions; and mixing, curing, sampling, and testing. The discussion of results centered around compressive strength and expansion by internal sulfate attack. It was concluded that with proper proportioning, by-products of pulverized and fluidized bed combustion promote binding of sand particles and provide adequate strength under various curing and moisture conditions 4 refs., 6 tabs.

  20. Combustion and environmental performance of clean coal end products

    Energy Technology Data Exchange (ETDEWEB)

    Skodras, G.; Sakellaropoulos, G. [Centre for Research and Technology, Hellas, Ptolemaidas-Kozanis, Ptolemaida (Greece). Inst. for Solid Fuel Technolgy and Applications]|[Aristotle Univ. of Thessaloniki, Thessaloniki (Greece). Dept. of Chemical Engineering, Chemical Process Engineering Lab]|[Chemical Process Engineering Research Inst., Thessaloniki (Greece). Lab. of Solid Fuels and Environment; Someus, E. [Thermal Desorption Technology Group (Greece); Grammelis, P.; Amarantos, P.S. [Centre for Research and Technology, Hellas, Ptolemaidas-Kozanis, Ptolemaida (Greece). Inst. for Solid Fuel Technolgy and Applications; Palladas, A.; Basinas, P.; Natas, P.; Prokopidou, M.; Diamantopoulou, I.; Sakellaropoulos, G. [Aristotle Univ. of Thessaloniki, Thessaloniki (Greece). Dept. of Chemical Engineering, Chemical Process Engineering Lab

    2006-07-01

    Clean and affordable power production is needed in order to achieve sustainable economic development. This paper focused on clean coal technologies in which coal-fired power plants are used in conjunction with large amounts of renewable energy sources to offer a high level of process safety and long term management of all residual operation streams. Thermal Desorption Recycle-Reduce-Reuse Technology (TDT-3R) was described as being a promising solid fuel pretreatment process for clean energy production up to 300 MWe capacities. TDT-3R is based on low temperature carbonisation fuel pre-treatment principles, which produce cleansed anthracite type fuels from coal and other carbonaceous material such as biomass and organic wastes. The combustion efficiency of such clean coals and the environmental performance of the TDT-3R process were investigated in this study via pilot scale tests of clean fuel production. Tests included flue gas emissions monitoring, raw fuel and product characterisation and thermogravimetric tests, polychlorinated dibenzo-p-dioxins and dibenzo-furans, and heavy metals analyses, and toxicity tests. Raw material included coal and biomass, such as willow, straw and demolition wood. The fuels were heated in a rotary kiln operating at 550 degrees C under slightly vacuum conditions. Clean coals were tested either alone or in conjunction with biomass fuels in a pilot scale combustion facility at Dresden, Germany. The clean coal samples were shown to have higher fixed carbon and ash content and lower volatiles compared to the respective raw coal samples. The major advantage of the TDT-3R process is the production of fuels with much lower pollutants content. Low nitrogen, sulphur, chlorine and heavy metal contents result in produced fuels that have excellent environmental performance, allow boiler operation in higher temperatures and overall better efficiency. Moreover, the use of clean fuels reduces deposition problems in the combustion chamber due to the

  1. Enhanced Combustion Low NOx Pulverized Coal Burner

    Energy Technology Data Exchange (ETDEWEB)

    David Towle; Richard Donais; Todd Hellewell; Robert Lewis; Robert Schrecengost

    2007-06-30

    For more than two decades, Alstom Power Inc. (Alstom) has developed a range of low cost, infurnace technologies for NOx emissions control for the domestic U.S. pulverized coal fired boiler market. This includes Alstom's internally developed TFS 2000{trademark} firing system, and various enhancements to it developed in concert with the U.S. Department of Energy. As of the date of this report, more than 270 units representing approximately 80,000 MWe of domestic coal fired capacity have been retrofit with Alstom low NOx technology. Best of class emissions range from 0.18 lb/MMBtu for bituminous coal to 0.10 lb/MMBtu for subbituminous coal, with typical levels at 0.24 lb/MMBtu and 0.13 lb/MMBtu, respectively. Despite these gains, NOx emissions limits in the U.S. continue to ratchet down for new and existing boiler equipment. On March 10, 2005, the Environmental Protection Agency (EPA) announced the Clean Air Interstate Rule (CAIR). CAIR requires 25 Eastern states to reduce NOx emissions from the power generation sector by 1.7 million tons in 2009 and 2.0 million tons by 2015. Low cost solutions to meet such regulations, and in particular those that can avoid the need for a costly selective catalytic reduction system (SCR), provide a strong incentive to continue to improve low NOx firing system technology to meet current and anticipated NOx control regulations. The overall objective of the work is to develop an enhanced combustion, low NOx pulverized coal burner, which, when integrated with Alstom's state-of-the-art, globally air staged low NOx firing systems will provide a means to achieve: Less than 0.15 lb/MMBtu NOx emissions when firing a high volatile Eastern or Western bituminous coal, Less than 0.10 lb/MMBtu NOx emissions when firing a subbituminous coal, NOx reduction costs at least 25% lower than the costs of an SCR, Validation of the NOx control technology developed through large (15 MWt) pilot scale demonstration, and Documentation required for

  2. Species-and stage-specific differences in trace element tissue concentrations in amphibians: implications for the disposal of coal-combustion wastes

    International Nuclear Information System (INIS)

    Roe, John H.; Hopkins, William A.; Jackson, Brian P.

    2005-01-01

    Information on species-and stage-specific patterns of contaminant accumulation is generally lacking for amphibians, yet such information could provide valuable knowledge on how amphibians interact with contaminants. We assessed concentrations of As, Cd, Cu, Ni, Pb, Se, Sr, and Zn in whole bodies of larval, recently metamorphosed, and adult life stages in Bufo terrestris and Rana sphenocephala from a site that currently receives coal combustion waste (CCW) discharge, a site where CCW was formerly discharged that has undergone natural attenuation for 30 years, and a nearby reference site. For the majority of elements (As, Cd, Cu, Ni, Pb, Zn), concentrations were highest in larvae, but Se and Sr concentrations remained elevated in later life stages, likely because these elements are S and Ca analogs, respectively, and are thus retained throughout structural changes during metamorphosis. Element concentrations were generally higher in B. terrestris than in R. sphenocephala. Concentrations of As, Se, and Sr were up to 11-35 times higher in metamorphs emigrating from CCW-polluted wetlands compared to unpolluted wetlands, suggesting metamorphosed amphibians can transport trace elements from aquatic disposal basins to nearby uncontaminated terrestrial habitats. In addition, anurans utilizing naturally revegetated sites up to 30 years after CCW disposal ceases are exposed to trace elements, although to a lesser degree than sites where CCW is currently discharged. - Results suggest that metamorphosed amphibians can transport trace elements from aquatic disposal basins to non-contaminated habitats

  3. Species-and stage-specific differences in trace element tissue concentrations in amphibians: implications for the disposal of coal-combustion wastes

    Energy Technology Data Exchange (ETDEWEB)

    Roe, John H. [University of Georgia, Savannah River Ecology Laboratory, P.O. Drawer E, Aiken, SC 29802 (United States); Hopkins, William A. [University of Georgia, Savannah River Ecology Laboratory, P.O. Drawer E, Aiken, SC 29802 (United States)]. E-mail: hopkins@srel.edu; Jackson, Brian P. [University of Georgia, Savannah River Ecology Laboratory, P.O. Drawer E, Aiken, SC 29802 (United States)

    2005-07-15

    Information on species-and stage-specific patterns of contaminant accumulation is generally lacking for amphibians, yet such information could provide valuable knowledge on how amphibians interact with contaminants. We assessed concentrations of As, Cd, Cu, Ni, Pb, Se, Sr, and Zn in whole bodies of larval, recently metamorphosed, and adult life stages in Bufo terrestris and Rana sphenocephala from a site that currently receives coal combustion waste (CCW) discharge, a site where CCW was formerly discharged that has undergone natural attenuation for 30 years, and a nearby reference site. For the majority of elements (As, Cd, Cu, Ni, Pb, Zn), concentrations were highest in larvae, but Se and Sr concentrations remained elevated in later life stages, likely because these elements are S and Ca analogs, respectively, and are thus retained throughout structural changes during metamorphosis. Element concentrations were generally higher in B. terrestris than in R. sphenocephala. Concentrations of As, Se, and Sr were up to 11-35 times higher in metamorphs emigrating from CCW-polluted wetlands compared to unpolluted wetlands, suggesting metamorphosed amphibians can transport trace elements from aquatic disposal basins to nearby uncontaminated terrestrial habitats. In addition, anurans utilizing naturally revegetated sites up to 30 years after CCW disposal ceases are exposed to trace elements, although to a lesser degree than sites where CCW is currently discharged. - Results suggest that metamorphosed amphibians can transport trace elements from aquatic disposal basins to non-contaminated habitats.

  4. Species- and stage-specific differences in trace element tissue concentrations in amphibians: implications for the disposal of coal-combustion wastes

    Energy Technology Data Exchange (ETDEWEB)

    Roe, J.H.; Hopkins, W.A.; Jackson, B.P. [University of Georgia, Aiken, SC (US)

    2005-07-01

    Information on species- and stage-specific patterns of contaminant accumulation is generally lacking for amphibians, yet such information could provide valuable knowledge on how amphibians interact with contaminants. We assessed concentrations of As, Cd, Cu, Ni, Pb, Se, Sr, and Zn in whole bodies of larval, recently metamorphosed, and adult life stages in Bufo terrestris and Rana sphenocephala from a site that currently receives coal combustion waste (CCW) discharge, a site where CCW was formerly discharged that has undergone natural attenuation for 30 years, and a nearby reference site. For the majority of elements (As, Cd, Cu, Ni, Pb, Zn), concentrations were highest in larvae, but Se and Sr concentrations remained elevated in later life stages, likely because these elements are S and Ca analogs, respectively, and are thus retained throughout structural changes during metamorphosis. Element concentrations were generally higher in B. terrestris than in R. sphenocephala. Concentrations of As, Se, and Sr were up to 11-35 times higher in metamorphs emigrating from CCW-polluted wetlands compared to unpolluted wetlands, suggesting metamorphosed amphibians can transport trace elements from aquatic disposal basins to nearby uncontaminated terrestrial habitats. In addition, anurans utilizing naturally revegetated sites up to 30 years after CCW disposal ceases are exposed to trace elements, although to a lesser degree than sites where CCW is currently discharged.

  5. 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.

  6. Environmental care in coal combustion

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2005-07-01

    Kvaerner Power will supply a CYMIC{reg_sign} circulating fluidized bed (CFB) boiler with a 63 MW electricity capacity to Manitowoc Public Utilities, in Manitowoc, Wisconsin, USA in 2006. This boiler is designed to burn bituminous coal and petroleum coke, with minimised emissions of SO{sub 2} and NOx. Kvaerner Power CFBs are capable of burning either coal or biomass (eg paper pellets) in any combination. Recent deliveries, to Indonesia and China as well as the USA, are listed. 1 tab., 5 photos.

  7. Predicting the combustion kinetics of Chinese coals

    Energy Technology Data Exchange (ETDEWEB)

    Niksa, Stephen [Niksa Energy Associates LLC, Belmont, CA (United States); Fujiwara, Naoki [Idemitsu Kosan Co., Ltd, Chiba (Japan). Coal and Environment Research Lab.

    2013-07-01

    The database on the devolatilization of Chinese coals in the English literature represents coals from all ranks and the major Chinese mines. It was mostly acquired with TGAs. There are sufficient datasets from devices that imposed rapid heating rates to bracket combustor behavior. The domains of heating rate, temperature, pressure, and particle size are either directly relevant to combustion conditions, or close enough to manage with modest extrapolations. Whereas the data on ultimate total yields is sufficient to validate a model for any coal type, more detailed product distributions and char compositions would be desirable. Based on the accurate interpretation of this database, there are few unresolved issues surrounding the applicability of FLASHCHAIN {sup registered} for combustion applications in China. The sub-database on devolatilization under rapid heating conditions represents 34 samples. The predicted yields were within the measurement uncertainties of 4 daf wt. % for 29 of these coals. Among the five ultimate yields that were not accurately predicted, three had measured values less than the proximate volatile matter (PVM), despite the rapid heating rates in the tests. Similarly, the sub-database on devolatilization under slow heating conditions characterizes ultimate devolatilization yields of 30 samples. The predicted yields were within the measurement uncertainties for 22 of these coals. Among the eight that were not accurately predicted, three had measured values that were much lower than the PVM (which is a problem even after accounting for the slow heating rates in the tests) and three were in studies that did not report ultimate analyses for the coals tested. Unfortunately, the database on the combustion behavior of the chars from Chinese coals is insufficient to specify char oxidation kinetics.

  8. Modification of combustion behaviour and NO emissions by coal blending

    Energy Technology Data Exchange (ETDEWEB)

    Rubiera, Fernando; Arenillas, Ana; Arias, Borja; Pis, Jose J. [Department of Energy and Environment, Instituto Nacional del Carbon, CSIC, Apartado 73, 33080 Oviedo (Spain)

    2002-06-20

    Combustion profiles determined by TGA and experiments in a laminar entrained flow reactor (EFR) were used in this work to assess the relative combustion reactivities of different rank coals and their binary coal blends. The combustion behaviour of coal blends in TGA was greatly influenced by coal rank and the proportion of each component in the blend. Higher volatile coals exerted more influence in the low-temperature region and less reactive coals in the char combustion zone. The results in the EFR indicated that coal blends burnout and NO emissions show additivity in the case of similar nature coals. When one of the components was a high-rank coal, the burnout of the blend exhibited, in some cases, positive synergistic effects, while a clear deviation from linearity was found in NO emissions.

  9. Catalytic Combustion of Gasified Waste

    Energy Technology Data Exchange (ETDEWEB)

    Kusar, Henrik

    2003-09-01

    This thesis concerns catalytic combustion for gas turbine application using a low heating-value (LHV) gas, derived from gasified waste. The main research in catalytic combustion focuses on methane as fuel, but an increasing interest is directed towards catalytic combustion of LHV fuels. This thesis shows that it is possible to catalytically combust a LHV gas and to oxidize fuel-bound nitrogen (NH{sub 3}) directly into N{sub 2} without forming NO{sub x} The first part of the thesis gives a background to the system. It defines waste, shortly describes gasification and more thoroughly catalytic combustion. The second part of the present thesis, paper I, concerns the development and testing of potential catalysts for catalytic combustion of LHV gases. The objective of this work was to investigate the possibility to use a stable metal oxide instead of noble metals as ignition catalyst and at the same time reduce the formation of NO{sub x} In paper II pilot-scale tests were carried out to prove the potential of catalytic combustion using real gasified waste and to compare with the results obtained in laboratory scale using a synthetic gas simulating gasified waste. In paper III, selective catalytic oxidation for decreasing the NO{sub x} formation from fuel-bound nitrogen was examined using two different approaches: fuel-lean and fuel-rich conditions. Finally, the last part of the thesis deals with deactivation of catalysts. The various deactivation processes which may affect high-temperature catalytic combustion are reviewed in paper IV. In paper V the poisoning effect of low amounts of sulfur was studied; various metal oxides as well as supported palladium and platinum catalysts were used as catalysts for combustion of a synthetic gas. In conclusion, with the results obtained in this thesis it would be possible to compose a working catalytic system for gas turbine application using a LHV gas.

  10. Slagging behavior of upgraded brown coal and bituminous coal in 145 MW practical coal combustion boiler

    Energy Technology Data Exchange (ETDEWEB)

    Akiyama, Katsuya; Pak, Haeyang; Takubo, Yoji [Kobe Steel, Ltd, Kobe (Japan). Mechanical Engineering Research Lab.; Tada, Toshiya [Kobe Steel, Ltd, Takasago (Japan). Coal and Energy Technology Dept.; Ueki, Yasuaki [Nagoya Univ. (Japan). Energy Science Div.; Yoshiie, Ryo; Naruse, Ichiro [Nagoya Univ. (Japan). Dept. of Mechanical Science and Engineering

    2013-07-01

    The purpose of this study is to quantitatively evaluate behaviors of ash deposition during combustion of Upgraded Brown Coal (UBC) and bituminous coal in a 145 MW practical coal combustion boiler. A blended coal consisting 20 wt% of the UBC and 80 wt% of the bituminous coal was burned for the combustion tests. Before the actual ash deposition tests, the molten slag fractions of ash calculated by chemical equilibrium calculations under the combustion condition was adopted as one of the indices to estimate the tendency of ash deposition. The calculation results showed that the molten slag fraction for UBC ash reached approximately 90% at 1,523 K. However, that for the blended coal ash became about 50%. These calculation results mean that blending the UBC with a bituminous coal played a role in decreasing the molten slag fraction. Next, the ash deposition tests were conducted, using a practical pulverized coal combustion boiler. A water-cooled stainless-steel tube was inserted in locations at 1,523 K in the boiler to measure the amount of ash deposits. The results showed that the mass of deposited ash for the blended coal increased and shape of the deposited ash particles on the tube became large and spherical. This is because the molten slag fraction in ash for the blended coal at 1,523 K increased and the surface of deposited ash became sticky. However, the mass of the deposited ash for the blended coal did not greatly increase and no slagging problems occurred for 8 days of boiler operation under the present blending conditions. Therefore, appropriate blending of the UBC with a bituminous coal enables the UBC to be used with a low ash melting point without any ash deposition problems in a practical boiler.

  11. Indoor Emissions from the Household Combustion of Coal

    Science.gov (United States)

    Learn about the lung cancer risk associated with burning coal inside your home. Indoor emissions from the household combustion of coal contain harmful chemicals such as benzene, carbon monoxide, and formaldehyde.

  12. Use of combustible wastes as fuel

    Energy Technology Data Exchange (ETDEWEB)

    Kotler, V.R.; Salamov, A.A.

    1983-01-01

    Achievements of science and technology in creating and using units for combustion of wastes with recovery of heat of the escaping gases has been systematized and generalized. Scales and outlooks are examined for the use of general, industrial and agricultural waste as fuel, composition of the waste, questions of planning and operating units for combustion of solid refuse, settling of waste water and industrial and agricultural waste. Questions are covered for preparing them for combustion use in special units with recovery of heat and at ES, aspects of environmental protection during combustion of waste, cost indicators of the employed methods of recovering the combustible waste.

  13. Radioactivity of combustion residues from coal-fired power stations

    International Nuclear Information System (INIS)

    Vom Berg, W.; Puch, K.H.

    1996-01-01

    Each year in Germany, about 18 mill. t of combustion residues are produced from the combustion of bituminous coal and lignite. They are utilized to a great extent in the construction industry and in mining. During the combustion of coal, the radio-nuclides remain predominantly in the ash. The radionuclide concentration in lignite ash is within the range of that in natural soil. The combustion residues of bituminous coal contain radio-nuclides of a similar order of magnitude as also can occur in natural rock. The utilization of combustion residues in construction materials makes a negligible contribution to radiation exposure through retention in buildings. (orig.) [de

  14. Dioxin emissions from coal combustion in domestic stove: Formation in the chimney and coal chlorine content influence

    Directory of Open Access Journals (Sweden)

    Paradiz Bostjan

    2015-01-01

    Full Text Available Combustion experiments conducted in domestic stove burning hard coal demonstrated a predominant influence of the coal chlorine content on the PCDD/F emissions, together with a pronounced effect of the flue gas temperature. PCDD/F concentrations of over 100 ng TEQ/m3, three orders of magnitude higher than in a modern waste incinerator, were measured in the flue gases of a domestic stove when combusting high chlorine coal (0.31 %. The PCDD/F concentrations in the flue gases dropped below 0,5 ng TEQ/m3, when low chlorine coal (0.07 % was used. When low chlorine coal was impregnated with NaCl to obtain 0.38 % chlorine content, the emission of the PCDD/Fs increased by two orders of magnitude. Pronounced nonlinearity of the PCDD/F concentrations related to chlorine content in the coal was observed. The combustion of the high chlorine coal yielded PCDD/F concentrations in flue gases one order of magnitude lower in a fan cooled chimney when compared to an insulated one, thus indicating formation in the chimney. The influence of flue gas temperature on the PCDD/F emissions was less pronounced when burning low chlorine coal. The predominant pathway of the PCDD/F emissions is via flue gases, 99 % of the TEQ in the case of the high chlorine coal for insulated chimney.

  15. 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.

  16. SELECTION OF SUSTAINABLE TECHNOLOGIES FOR COMBUSTION OF BOSNIAN COALS

    Directory of Open Access Journals (Sweden)

    Anes Kazagić

    2010-01-01

    Full Text Available This paper deals with optimization of coal combustion conditions to support selection a sustainable combustion technology and an optimal furnace and boiler design. A methodology for optimization of coal combustion conditions is proposed and demonstrated on the example of Bosnian coals. The properties of Bosnian coals vary widely from one coal basin to the next, even between coal mines within the same basin. Very high percentage of ash (particularly in Bosnian brown coal makes clear certain differences between Bosnian coal types and other world coal types, providing a strong argument for investigating specific problems related to the combustion of Bosnian coals, as well as ways to improve their combustion behaviour. In this work, options of the referent energy system (boiler with different process temperatures, corresponding to the different combustion technologies; pulverised fuel combustion (slag tap or dry bottom furnace and fluidized bed combustion, are under consideration for the coals tested. Sustainability assessment, based on calculation economic and environment indicators, in combination with common low cost planning method, is used for the optimization. The total costs in the lifetime are presented by General index of total costs, calculated on the base of agglomeration of basic economic indicators and the economic indicators derived from environmental indicators. So, proposed methodology is based on identification of those combustion technologies and combustion conditions for coals tested for which the total costs in lifetime of the system under consideration are lowest, provided that all environmental issues of the energy system is fulfilled during the lifetime. Inputs for calculation of the sustainability indicators are provided by the measurements on an experimental furnace with possibility of infinite variation of process temperature, supported by good praxis from the power plants which use the fuels tested and by thermal

  17. Prevention of spontaneous combustion of backfilled plant waste material.

    CSIR Research Space (South Africa)

    Adamski, SA

    2003-06-01

    Full Text Available Since Grootegeluk Coal Mine commenced operation in 1980 all plant discards and inter-burden material have been stacked on discards dumps, a practice that has led to the spontaneous combustion of the waste material on these dumps. From 1980 to 1988...

  18. A study on the combustion behaviour of coal blends

    Energy Technology Data Exchange (ETDEWEB)

    Rubiera, F.; Fuente, E.; Arenillas, A.; Pis, J.J. [Instituto Nacional del Carbon, Oviedo (Spain)

    1999-07-01

    Combustion behaviour of four coals of varying rank and their binary blends was studied using temperature programmed combustion tests, and thermogravimetric analysis. Characteristic parameters could not be predicted from the weight percentage of individual coals in the blend. 6 refs., 4 figs., 1 tab.

  19. Oxy-Fuel Combustion of Coal

    DEFF Research Database (Denmark)

    Brix, Jacob

    This Ph.D. thesis describes an experimental and modeling investigation of the thermal conversion of coal and an experimental investigation of the emission of NO from char combustion in O2/N2 and O2/CO2 atmospheres. The motivation for the work has been the prospective use of the technology “Oxy......-Fuel Combustion” as a mean of CO2 abatement in large scale energy conversion. Entrained Flow Reactor (EFR) experiments have been conducted in O2/N2 and O2/CO2 mixtures in the temperature interval 1173 K – 1673 K using inlet O2 concentrations between 5 – 28 vol. %. Bituminous coal has been used as fuel in all....... % it was found that char conversion rate was lowered in O2/CO2 compared to O2/N2. This is caused by the lower diffusion coefficient of O2 in CO2 (~ 22 %) that limits the reaction rate in zone III compared to combustion in O2/N2. Using char sampled in the EFR experiments ThermoGravimetric Analyzer (TGA...

  20. Identification and quantification of priority species from coal combustion

    Energy Technology Data Exchange (ETDEWEB)

    Furimsky, E.; Zheng, L.; Hlavacek, T. [Canada Centre for Mineral and Energy Technology, Ottawa, ON (Canada). Energy Research Laboratories

    1996-07-01

    The objective is to quantify and characterize emissions from pulverized coal combustion of seven coals and the circulating fluidized bed combustion of four coals. The species of particular interest are sulphur, nitrogen, chlorine, arsenic, mercury, lead, cadmium, potassium, and sodium. The Facility for Analysis of Chemical Thermodynamics (F{asterisk}A{asterisk}C{asterisk}T) method is used to predict type and amount of priority species. Prediction is made for combustion with and without the presence of limestone. The results show that the combustion technology used influences the amount of priority species emitted. 16 tabs., 3 apps.

  1. 30 CFR 57.4104 - Combustible waste.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Combustible waste. 57.4104 Section 57.4104... Control Prohibitions/precautions/housekeeping § 57.4104 Combustible waste. (a) Waste materials, including liquids, shall not accumulate in quantities that could create a fire hazard. (b) Waste or rags containing...

  2. DEVELOPMENT OF A VORTEX CONTAINMENT COMBUSTOR FOR COAL COMBUSTION SYTEMS

    Science.gov (United States)

    The report describes the development of a vortex containment combustor (VCC) for coal combustion systems, designed to solve major problems facing the conversion of oil- and gas-fired boilers to coal (e.g., derating, inorganic impurities in coal, and excessive formation of NOx and...

  3. Large-eddy simulation of swirling pulverized-coal combustion

    Energy Technology Data Exchange (ETDEWEB)

    Hu, L.Y.; Luo, Y.H. [Shanghai Jiaotong Univ. (China). School of Mechanical Engineering; Zhou, L.X.; Xu, C.S. [Tsinghua Univ., Beijing (China). Dept. of Engineering Mechanics

    2013-07-01

    A Eulerian-Lagrangian large-eddy simulation (LES) with a Smagorinsky-Lilly sub-grid scale stress model, presumed-PDF fast chemistry and EBU gas combustion models, particle devolatilization and particle combustion models are used to study the turbulence and flame structures of swirling pulverized-coal combustion. The LES statistical results are validated by the measurement results. The instantaneous LES results show that the coherent structures for pulverized coal combustion is stronger than that for swirling gas combustion. The particles are concentrated in the periphery of the coherent structures. The flame is located at the high vorticity and high particle concentration zone.

  4. Low temperature combustion of organic coal-water fuel droplets containing petrochemicals while soaring in a combustion chamber model

    Directory of Open Access Journals (Sweden)

    Valiullin Timur R.

    2017-01-01

    Full Text Available The paper examines the integral characteristics (minimum temperature, ignition delay times of stable combustion initiation of organic coal-water fuel droplets (initial radius is 0.3-1.5 mm in the oxidizer flow (the temperature and velocity varied in ranges 500-900 K, 0.5-3 m/s. The main components of organic coal-water fuel were: brown coal particles, filter-cakes obtained in coal processing, waste engine, and turbine oils. The different modes of soaring and ignition of organic coal-water fuel have been established. The conditions have been set under which it is possible to implement the sustainable soaring and ignition of organic coal-water fuel droplets. We have compared the ignition characteristics with those defined in the traditional approach (based on placing the droplets on a low-inertia thermocouple junction into the combustion chamber. The paper shows the scale of the influence of heat sink over the thermocouple junction on ignition inertia. An original technique for releasing organic coal-water fuel droplets to the combustion chamber was proposed and tested. The limitations of this technique and the prospects of experimental results for the optimization of energy equipment operation were also formulated.

  5. The release of nitrogen in coal combustion and pyrolysis

    International Nuclear Information System (INIS)

    Varey, J.E.; Hindmarsh, C.J.; Thomas, K.M.

    1994-01-01

    Environmental aspects of coal utilization are a major concern. Recent advances in the development of low NO x burners and the emerging technologies of fluidized bed combustion have led to the identification of coal char nitrogen as the major contributor to the nitrogen oxides released during combustion. The temperature programmed combustion and pyrolysis of a series of coals covering a wide range of rank have been investigated. In addition, maceral concentrates have been investigated to assess the variation in the combustion behavior and the release of nitrogen in the pyrolysis and combustion of macerals. This investigation has involved the use of thermogravimetric analysis - mass spectrometry (TG-MS) with two sampling options: (1) ∼1cm from the sample and (2) at the exit of the TG. The former allows reactive species to be identified in the combustion of the coals. These temperature programmed combustion results have been compared with similar measurements carried out at the exit of the TG where the products are at equilibrium. In addition, pyrolysis studies have been carried out under similar conditions. The results show that reactive intermediate species such as HCN, (CN) 2 , COS etc. can be detected in the combustion products. The evolution of these species during combustion are compared with the pyrolysis products of the coal. The results are discussed in relation to the structure of the coals and the conversion of volatile species and char nitrogen to nitrogen oxides

  6. Combustion behaviour of ultra clean coal obtained by chemical demineralisation

    Energy Technology Data Exchange (ETDEWEB)

    F. Rubiera; A. Arenillas; B. Arias; J.J. Pis; I. Suarez-Ruiz; K.M. Steel; J.W. Patrick [Instituto Nacional del Carbon, CSIC, Oviedo (Spain)

    2003-10-01

    The increasing environmental concern caused by the use of fossil fuels and the concomitant need for improved combustion efficiency is leading to the development of new coal cleaning and utilisation processes. However, the benefits achieved by the removal of most mineral matter from coal either by physical or chemical methods can be annulled if poor coal combustibility characteristics are attained. In this work a high volatile bituminous coal with 6% ash content was subjected to chemical demineralisation via hydrofluoric and nitric acid leaching, the ash content of the clean coal was reduced to 0.3%. The original and treated coals were devolatilised in a drop tube furnace and the structure and morphology of the resultant chars was analysed by optical and scanning electron microscopies. The reactivity characteristics of the chars were studied by isothermal combustion tests in air at different temperatures in a thermogravimetric system. Comparison of the combustion behaviour and pollutant emissions of both coals was conducted in a drop tube furnace operating at 1000{sup o}C. The results of this work indicate that the char obtained from the chemically treated coal presents very different structure, morphology and reactivity behaviour than the char from the original coal. The changes induced by the chemical treatment increased the combustion efficiency determined in the drop tube furnace, in fact higher burnout levels were obtained for the demineralised coal.

  7. Effect of the grinding behaviour of coal blends on coal utilisation for combustion

    Energy Technology Data Exchange (ETDEWEB)

    Rubiera, F.; Arenillas, A.; Fuente, E.; Pis, J.J. [Inst. Nacional del Carbon, CSIC, Oviedo (Spain); Miles, N. [School of Chemical, Environmental and Mining Engineering, Nottingham Univ. (United Kingdom)

    1999-11-01

    Grinding of a high volatile bituminous coal was performed in three comminution devices: Raymond Mill (RM), Rolls Crusher (RC) and Ball Mill (BM). The pulverised samples were sieved to obtain four particle size fractions, and temperature-programmed combustion (TPC) was used for the evaluation of their combustion behaviour. In addition, three coals of different hardness and rank were mixed in various proportions in order to compare the combustibility characteristics of the binary coal blends with those of the individual coals. The effect of coal blending on grindability was also studied. It was found that grindability was non-additive especially when coals of very different hardgrove grindability index (HGI) were blended. The combustion studies also suggested that there exists an interaction between individual coals when they are burnt as a blend. (orig.)

  8. Method for storing radioactive combustible waste

    Science.gov (United States)

    Godbee, H.W.; Lovelace, R.C.

    1973-10-01

    A method is described for preventing pressure buildup in sealed containers which contain radioactively contaminated combustible waste material by adding an oxide getter material to the container so as to chemically bind sorbed water and combustion product gases. (Official Gazette)

  9. Possibility of Coal Combustion Product Conditioning

    Science.gov (United States)

    Błaszczyński, Tomasz Z.; Król, Maciej R.

    2018-03-01

    This paper is focused on properties of materials known as green binders. They can be used to produce aluminium-siliceous concrete and binders known also as geopolymers. Comparing new ecological binders to ordinary cements we can see huge possibility of reducing amount of main greenhouse gas which is emitted to atmosphere by 3 to even 10 times depending of substrate type used to new green material production. Main ecological source of new materials obtaining possibility is to use already available products which are created in coal combustion and steel smelting process. Most of them are already used in many branches of industry. They are mostly civil engineering, chemistry or agriculture. Conducted research was based on less popular in civil engineering fly ash based on lignite combustion. Materials were examine in order to verify possibility of obtaining hardened mortars based of different factors connected with process of geopolymerization, which are temperature, amount of reaction reagent and time of heat treatment. After systematizing the matrices for the basic parameters affecting the strength of the hardened mortars, the influence of the fly ash treatment for increasing the strength was tested.

  10. Emissions from carpet combustion in a pilot-scale rotary kiln: comparison with coal and particle-board combustion

    Energy Technology Data Exchange (ETDEWEB)

    Stephanie Lucero Konopa; James A. Mulholland; Matthew J. Realff; Paul M. Lemieux [Georgia Institute of Technology, Atlanta, GA (United States). School of Civil and Environmental Engineering

    2008-08-15

    The use of post-consumer carpet as a potential fuel substitute in cement kilns and other high-temperature processes is being considered to address the problem of huge volumes of carpet waste and the opportunity of waste-to-energy recovery. Carpet represents a high volume waste stream, provides high energy value, and contains other recoverable materials for the production of cement. This research studied the emission characteristics of burning 0.46-kg charges of chopped nylon carpet squares, pulverized coal, and particle-board pellets in a pilot-scale natural gas-fired rotary kiln. Carpet was tested with different amounts of water added. Emissions of oxygen, carbon dioxide, nitric oxide (NO), sulfur dioxide (SO{sub 2}), carbon monoxide (CO), and total hydrocarbons and temperatures were continuously monitored. It was found that carpet burned faster and more completely than coal and particle board, with a rapid volatile release that resulted in large and variable transient emission peaks. NO emissions from carpet combustion ranged from 0.06 to 0.15 g/MJ and were inversely related to CO emissions. Carpet combustion yielded higher NO emissions than coal and particleboard combustion, consistent with its higher nitrogen content. S{sub 2} emissions were highest for coal combustion, consistent with its higher sulfur content than carpet or particle board. Adding water to carpet slowed its burn time and reduced variability in the emission transients, reducing the CO peak but increasing NO emissions. Results of this study indicate that carpet waste can be used as an effective alternative fuel, with the caveats that it might be necessary to wet carpet or chop it finely to avoid excessive transient puff emissions due to its high volatility compared with other solid fuels, and that controlled mixing of combustion air might be used to control NO emissions from nylon carpet. 13 refs., 5 figs., 1 tab.

  11. Environmental optimisation of waste combustion

    Energy Technology Data Exchange (ETDEWEB)

    Schuster, Robert [AaF Energikonsult, Stockholm (Sweden); Berge, Niclas; Stroemberg, Birgitta [TPS Termiska Processer AB, Nykoeping (Sweden)

    2000-12-01

    The regulations concerning waste combustion evolve through R and D and a strive to get better and common regulations for the European countries. This study discusses if these rules of today concerning oxygen concentration, minimum temperature and residence time in the furnace and the use of stand-by burners are needed, are possible to monitor, are the optimum from an environmental point of view or could be improved. No evidence from well controlled laboratory experiments validate that 850 deg C in 6 % oxygen content in general is the best lower limit. A lower excess air level increase the temperature, which has a significant effect on the destruction of hydrocarbons, favourably increases the residence time, increases the thermal efficiency and the efficiency of the precipitators. Low oxygen content is also necessary to achieve low NO{sub x}-emissions. The conclusion is that the demands on the accuracy of the measurement devices and methods are too high, if they are to be used inside the furnace to control the combustion process. The big problem is however to find representative locations to measure temperature, oxygen content and residence time in the furnace. Another major problem is that the monitoring of the operation conditions today do not secure a good combustion. It can lead to a false security. The reason is that it is very hard to find boilers without stratifications. These stratifications (stream lines) has each a different history of residence time, mixing time, oxygen and combustible gas levels and temperature, when they reach the convection area. The combustion result is the sum of all these different histories. The hydrocarbons emission is in general not produced at a steady level. Small clouds of unburnt hydrocarbons travels along the stream lines showing up as peaks on a THC measurement device. High amplitude peaks has a tendency to contain higher ratio of heavy hydrocarbons than lower peaks. The good correlation between some easily detected

  12. Methodology for Evaluating Encapsulated Beneficial Uses of Coal Combustion Residuals

    Science.gov (United States)

    The primary purpose of this document is to present an evaluation methodology developed by the EPA for making determinations about environmental releases from encapsulated products containing coal combustion residuals.

  13. Application of coal combustion residues to the stabilization/solidification of industrial wastes (IRIS); Desarrollo de un Proceso, a Escala Piloto de Inertizacion de Residuos Industriales con Cenizas Volantes

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-12-31

    Stabilization/solidification (S/S) processes, also called inertization processes, are a group of techniques which employ additives to reduce the mobility of the hazardous components from the waste and make possible for the residue to be accepted for its disposal in a safe way. These processes, mainly applied to wastes that contain heavy metals (such as lead, zinc, cadminum, mercury, copper, nickel, titanium, chromium-III, chromium-VI, arsenic,....) change the waste into a solid-like material in which the metals are trapped (nets and matrix) by physical or chemical links. The IRIS Project, carried out by AICIA through the ECSC Coal Programme with the participation of two industrial partners (Sevillana de Electricidad and EGMASA, a public-owned company for waste treatment), has developed, at pilot scale, a new S/S process for inorganic industrial wastes that uses great quantities of fly ash in the place of other more commonly used and expansive reagents. A pilot plant for 200 kg/h has been designed, built and operated. This facility has allowed to add improvements and scientific foundations to existing S/S technology. It has also allowed to obtain industrial scale parameters for fixed and portable plants. Experiencie have been mainly carried out using fly ash from high quality coals, but types of ash have been tested coming from coals with a greater calcium content, from fluidised bed combustion boilers and from desulphurisation processes, giving very suitable characteristics for their application to S/S processes. The addition of fly ash (up to 30%) in the IRIS process improves the results in comparison with the S/S processes that use only cement, because the final pH obtained (8-11) does not allow amphoteric metallic ions to escape in the leachate. The same as other S/S processes, IRIS can be applied also to wastes that contain certain metals (chromium-VI, arsenic, for example) with specific pre-treatments (redox, for example). The efficiency of the IRIS treatment

  14. NOx emissions and combustibility characteristics of coal blends

    Energy Technology Data Exchange (ETDEWEB)

    Rubiera, F.; Arenillas, A.; Arias, B.; Pis, J.J. [CSIC, Instituto Nacional del Carbon, Oviedo (Spain). Dept. of Energy and Environment

    2001-07-01

    In this work, a series of coals with different origin and rank were blended and several aspects of the resultant blends were studied. This included determination of the grindability of individual coals and blends by means of the Hardgrove Grindability Index (HGI), and temperature programmed combustion test, which were carried out in a thermogravimetric analyser (TG) coupled to a quadruple mass spectrometer (MS) for evolved gas analysis. Special attention was paid to the combustibility parameters and the NO emissions during blends combustion. It was found that while some coal blends present interaction between the individual coals, others do not. This behaviour was assumed to be due to the differences in coal structure and functional groups composition. 18 refs., 11 figs., 2 tabs.

  15. Combustion characterization of beneficiated coal-based fuels

    Energy Technology Data Exchange (ETDEWEB)

    Chow, O.K.; Levasseur, A.A.

    1995-11-01

    The Pittsburgh Energy Technology Center (PETC) of the U.S. Department of Energy is sponsoring the development of advanced coal-cleaning technologies aimed at expanding the use of the nation`s vast coal reserves in an environmentally and economically acceptable manner. Because of the lack of practical experience with deeply beneficiated coal-based fuels, PETC has contracted Combustion Engineering, Inc. to perform a multi-year project on `Combustion Characterization of Beneficiated Coal-Based Fuels.` The objectives of this project include: (1) the development of an engineering data base which will provide detailed information on the properties of Beneficiated Coal-Based Fuels (BCs) influencing combustion, ash deposition, ash erosion, particulate collection, and emissions; and (2) the application of this technical data base to predict the performance and economic impacts of firing the BCFs in various commercial boiler designs.

  16. Prevention of spontaneous combustion in coal stockpiles : Experimental results in coal storage yard

    NARCIS (Netherlands)

    Fierro, V.; Miranda, J.L.; Romero, C.; Andrés, J.M.; Arriaga, A.; Schmal, D.; Visser, G.H.

    1999-01-01

    The spontaneous ignition of coal stockpiles is a serious economic and safety problem. This paper deals with oxidation and spontaneous combustion of coal piles laid in coal storage yard and the measures to avoid the heat losses produced. Investigations on self heating were carried out with five test

  17. Atmospheric emission of mercury due to combustion of steam coal and domestic coal in China

    Science.gov (United States)

    Wang, Shaobin; Luo, Kunli

    2017-08-01

    To study the mercury emission due to the combustion of steam coal and domestic coal in China, we analyzed the mercury contents of coal, fly ash, bottom ash and sluicing water in thermal power plants, steam boilers as well as domestic coal-stoves, in Shaanxi, Shanxi, Shandong and Yunnan Provinces. This study conduct an estimate of the Hg emission rates from steam coal and domestic coal combustion based on the method of mass distribution ratio of fly ash and bottom ash. The results show that the Hg emission rate of coal combustion in thermal power plants is about 50.21% (electrostatic precipitators + wet flue gas desulfurization), and that in heating boilers is about 67.23%, and 92.28% in industrial boilers without flue gas desulphurisation equipment. Furthermore, Hg emission rate is 83.61% due to domestic coal combustion in coal-stoves. The Hg emission amount into the atmosphere from power and heat generation, industrial boilers, domestic coal-stoves and spontaneous combustion of coal gangue is roughly estimated to be 133 ± 4, 100 ± 17, 11 ± 0.1 and 47 ± 26 tons in China in 2014, respectively, and the total Hg emission amount from this paper is estimated at 292 tons. The trends of Hg emission in China from 1991 to 2014 show an accelerating growth after 2002. The proportion of mercury emission due to thermal power, heating generation and industrial energy utilization continuously increased. The atmospheric emission of mercury due to combustion of steam coal, domestic coal and coal gangue accounts nearly 50% in total anthropogenic Hg emissions in China, indicating one of the largest sources of Hg emission in China which should draw more public and scientific attention in the future.

  18. Biodesulfurization of coals of different rank: Effect on combustion behavior

    Energy Technology Data Exchange (ETDEWEB)

    Rubiera, F.; Arenillas, A.; Fuente, E.; Pis, J.J. [CSIC, Oviedo (Spain). Inst. Nacional del Carbon; Marteinz, O.; Moran, A. [Univ. de Leon (Spain). Escuela de Ingenieria Tecnica Minera

    1999-02-01

    The emission of sulfur oxides during the combustion of coal is one of the causes, among other air pollution problems, of acid rain. The contribution of coal as the mainstay of power production will be determined by whether its environmental performance is equal or superior to other supply options. In this context, desulfurization of coal before combustion by biological methods was studied. Four Spanish high-sulfur content coals of different rank were inoculated with bacteria isolated from mine-drainage waters and with naturally occurring bacteria inherent in the coals to be treated. Higher levels of desulfurization were obtained in the case of the samples treated with their own accompanying bacteria and when aeration was increased. All the samples were amenable to the biodepyritization processes. However, it is of little value to achieve large sulfur reductions if a decrease in coal combustion performance is obtained in the process. For this reason, a comparison was made between the combustibility characteristics of the original coals and those of the biodesulfurized samples. Results indicated that combustibility was not substantially modified by the overall biological treatment. The benefits of reduced sulfur emissions into the atmosphere ought to be taken into account as part of the general evaluation of the processes.

  19. Emissions of organic hazardous air pollutants during Chinese coal combustion

    Energy Technology Data Exchange (ETDEWEB)

    Yan, R.; Zhu, H.J.; Zheng, C.G.; Xu, M.H. [Environmental Technology Institute, Singapore (Singapore). Innovative Center

    2002-05-01

    The emissions of organic hazardous air pollutants (HAPs) during the combustion of several typical Chinese coals were investigated. First, the distribution of four types of HAP, i.e., aliphatics, cyclic hydrocarbons, monoaromatic compounds and PAHs, in the CH{sub 2}C{sub l2} extracts of six Chinese coals were studied and the influences of the extractive times and coal varieties were also evaluated. Second, the partitioning of these HAPs in the flue gas during coal combustion in a small-scale reactor were investigated, depending on oven temperatures (500, 600, 700, 800, 900{sup o}C) and coal varieties. The behaviors of HAP in the combustion flue gas were compared with those in the CH{sub 2}, Cl{sub 2}, extracts. Finally, combustion was conducted at given conditions in two laboratory-scale reactors: a fluidized bed and a fixed bed. Two coals (Shengmu bituminous coal and Xunhuan anthracite coal) and one coke were considered. The HAP partitioning both in flue gases and in ashes were evaluated and compared between the two combustors.

  20. 40 CFR 60.1555 - Are any small municipal waste combustion units exempt from my State plan?

    Science.gov (United States)

    2010-07-01

    ... qualifies for the exemption. (d) Municipal waste combustion units that combust only tires. Units are exempt... single-item waste stream of tires and no other municipal waste (the unit can co-fire coal, fuel oil.../rubber recycling units. Units are exempt from your State plan if four requirements are met: (1) The...

  1. The rheodynamics and combustion of coal-water mixtures

    Energy Technology Data Exchange (ETDEWEB)

    Burdukov, A.P.; Popov, V.I.; Tomilov, V.G.; Fedosenko, V.D. [Russian Academy of Science, Novosibirsk (Russian Federation). Inst. of Thermophysics (Siberian Branch, Russian Academy of Science)

    2002-05-01

    Investigation methods for characteristics of movement along the tubes, combustion dynamics and gasification of separate drops were developed for the coal-water mixtures (CWM). The following parameters were determined on the basis of laser heating: thermometric, pyrometric and concentration dynamics of single-drop combustion, complete combustion times, duration of temperature phases of combustion, as well as the moment and temperature of ignition. Information on the combustion mass velocity and gasification products was also obtained using laser heating. 6 refs., 13 figs., 1 tab.

  2. Gradual combustion - method for nitrogen oxide suppression during brown coal combustion

    Energy Technology Data Exchange (ETDEWEB)

    Kotler, V.P.; Verzakov, V.N.; Lobov, T.V.

    1990-10-01

    Discusses combustion of brown coal in BKZ-500-140-1 boilers and factors that influence emission of nitrogen oxides. Temperature distribution in the furnace was evaluated. Effects of burner position, burner number and burner type as well as air excess ratio on chemical reactions during brown coal combustion, formation of nitrogen oxides and their emission were comparatively evaluated. Analyses showed that by optimum arrangement of burners and selecting the optimum air excess ratio a part of nitrogen oxides formed during the initial phase of combustion was reduced to molecular nitrogen in the second phase. On the basis of evaluations the following recommendations for furnace design are made: use of straight-flow burners characterized by a reduced mixing ratio with secondary air, parallel arrangement of burners which guarantees mixing of the combustion products from the burners with stable and unstable combustion (products of incomplete coal combustion), reducing the air excess ratio to below 1.0. 5 refs.

  3. Preliminary experimental studies of waste coal gasification

    Energy Technology Data Exchange (ETDEWEB)

    Su, S.; Jin, Y.G.; Yu, X.X.; Worrall, R. [CSIRO, Brisbane, QLD (Australia). Advanced Coal Technology

    2013-07-01

    Coal mining is one of Australia's most important industries. It was estimated that coal washery rejects from black coal mining was approximately 1.82 billion tonnes from 1960 to 2009 in Australia, and is projected to produce another one billion tonnes by 2018 at the current production rate. To ensure sustainability of the Australian coal industry, we have explored a new potential pathway to create value from the coal waste through production of liquid fuels or power generation using produced syngas from waste coal gasification. Consequently, environmental and community impacts of the solid waste could be minimized. However, the development of an effective waste coal gasification process is a key to the new pathway. An Australian mine site with a large reserve of waste coal was selected for the study, where raw waste coal samples including coarse rejects and tailings were collected. After investigating the initial raw waste coal samples, float/sink testing was conducted to achieve a desired ash target for laboratory-scale steam gasification testing and performance evaluation. The preliminary gasification test results show that carbon conversions of waste coal gradually increase as the reaction proceeds, which indicates that waste coal can be gasified by a steam gasification process. However, the carbon conversion rates are relatively low, only reaching to 20-30%. Furthermore, the reactivity of waste coal samples with a variety of ash contents under N{sub 2}/air atmosphere have been studied by a home-made thermogravimetric analysis (TGA) apparatus that can make the sample reach the reaction temperature instantly.

  4. Atmospheric fluidized bed coal combustion research, development and application

    CERN Document Server

    Valk, M

    1994-01-01

    The use of fluidized bed coal combustion technology has been developed in the past decade in The Netherlands with a view to expanding the industrial use of coal as an energy supply. Various research groups from universities, institutes for applied science and from boiler industries participated and contributed to this research area. Comprehensive results of such recent experimentation and development work on atmospheric fluidized bed combustion of coal are covered in this volume. Each chapter, written by an expert, treats one specific subject and gives both the theoretical background as well a

  5. Radioactivity of coals and ash and slag wastes at coal-fired thermal power plants

    Science.gov (United States)

    Krylov, D. A.; Sidorova, G. P.

    2013-04-01

    This paper presents an analysis of published data on the content of radioactive nuclides in coals originating from various coal deposits, and in ash and slag wastes produced at coal-fired thermal power plants, as well as in fly ash emitted from thermal power plants into the atmosphere. Problems related to the use of coals with an elevated content of natural radionuclides (NRNs) and methods of their solution implemented at the Urtuyskoe coalfield are dealt with. Data on the analysis of Transbaikal coals for the NRN content, as well as weighted mean content of uranium and thorium in coals from the Siberian Region, are given. In order to reduce irradiation of plant personnel and the population of the areas where coal producers and coal-fired thermal power plants are located, it is necessary to organize very careful control of the NRN content in both coals and products of their combustion that are released into the environment. To solve the problem related to the control of radioactivity, the centralized approach and creation of a proper normative base are needed. Experience gained in developing the Urtuyskoe coalfield shows that it is possible to create an efficient system of coal quality control with respect to the radiation hygiene factor and provide protection of the environment and health of the population.

  6. LES and RANS modeling of pulverized coal combustion in swirl burner for air and oxy-combustion technologies

    International Nuclear Information System (INIS)

    Warzecha, Piotr; Boguslawski, Andrzej

    2014-01-01

    Combustion of pulverized coal in oxy-combustion technology is one of the effective ways to reduce the emission of greenhouse gases into the atmosphere. The process of transition from conventional combustion in air to the oxy-combustion technology, however, requires a thorough investigations of the phenomena occurring during the combustion process, that can be greatly supported by numerical modeling. The paper presents the results of numerical simulations of pulverized coal combustion process in swirl burner using RANS (Reynolds-averaged Navier–Stokes equations) and LES (large Eddy simulation) methods for turbulent flow. Numerical simulations have been performed for the oxyfuel test facility located at the Institute of Heat and Mass Transfer at RWTH Aachen University. Detailed analysis of the flow field inside the combustion chamber for cold flow and for the flow with combustion using different numerical methods for turbulent flows have been done. Comparison of the air and oxy-coal combustion process for pulverized coal shows significant differences in temperature, especially close to the burner exit. Additionally the influence of the combustion model on the results has been shown for oxy-combustion test case. - Highlights: • Oxy-coal combustion has been modeled for test facility operating at low oxygen ratio. • Coal combustion process has been modeled with simplified combustion models. • Comparison of oxy and air combustion process of pulverized coal has been done. • RANS (Reynolds-averaged Navier–Stokes equations) and LES (large Eddy simulation) results for pulverized coal combustion process have been compared

  7. Bromine based mercury abatement in waste and coal combustion. Mercury retention in the catalyst bed of a tail-end-SCR

    Energy Technology Data Exchange (ETDEWEB)

    Vosteen, Bernhard W. [Vosteen Consulting GmbH, Koeln (Germany); Kanefke, Rico; Beyer, Joachim; Bonkhofer, Theodor Gerhard [CURRENTA GmbH und Co. OHG, Leverkusen (Germany); Ullrich, Rick [WastePro Engineering Inc., Kennett Square, PA (United States)

    2008-07-01

    Observations and testing at a CURRENTA waste incineration plant and several coal fired power plants has derived the following aspects of mercury behavior in the plant's waste heat boiler and its gas cleaning train: - Hg{sub met} is oxidized to Hg{sub ion} most readily by bromine, and also by chlorine, - sulfur (SO{sub 2}) inhibit the Hg{sub met} chlorination but not the Hg{sub met} bromination, - Hg{sub met} passes through scrubbers and is adsorbed onto the catalyst bed of a tail-end SCR, slowly oxidized and finally elutes off as Hg{sub ion}, - sulfur (SO{sub 2}) impacts the reduction of molecular halogens in different ways; SO{sub 2} reduces Cl{sub 2} at elevated temperatures (boiler range), but reduces Br{sub 2} only at low temperatures (scrubber range) The operational tests and studies performed in the spring and summer of 2000 at this plant led to some specific knowledge about Hg{sub met} adsorption and also Hg{sub ion} desorption at the catalyst bed of a tail-end SCR. This knowledge, which was at that time in many respects novel, has provided more insight into the mercury oxidation behaviour. Today, process options derived from this knowledge could be implemented in hazardous waste incineration plants and also municipal solid waste incineration plants, to achieve complete mercury halogenation in the boiler flue gas, ahead of the scrubber system, at any time. This might prevent penetration of metallic mercury to the tail-end SCR and avoid the corresponding long time mercury elution. For effective prevention to be achieved in practice, it is strongly recommended to also install a continuously measuring (possibly uncalibrated) AAS mercury monitor for immediate detection of any unexpected Hg{sub met} breakthrough, for example caused by ''hidden mercury'' in the waste feed, and to initiate the rapid (preferably automized) injection of some bromine compound before even more mercury is transferred into the tail-end SCR, stored there as Hg

  8. Characterization of products of combustion of mineral coal

    International Nuclear Information System (INIS)

    Pinheiro, H.S.; Albuquerque, J. S. V.; Sales, J.C.; Nogueira, R.E.F.Q.

    2011-01-01

    During the burning of coal in power plants, various types of waste or by products are generated. These materials have been the subject of several studies. They contain ashes and have many technological applications, such as in the production of various types of ceramic pieces. The objective of this work was to study the feasibility of adding the coal combustion products as filler for ceramics. X-ray fluorescence analysis was used to identify and quantify the proportions of the elements contained in the sample and x-ray diffraction to identify the phases present. The analysis by X-ray diffraction revealed a diffraction pattern of silicon sulfide, calcium silicate and sulfide phases of Aluminium, Potassium and Titanium. X-ray fluorescence analysis showed silica (37.14%), calcium (21.86%), aluminum (14.69%) and sulfur (8.70%). These results show characteristics of materials with potential for incorporation in ceramic bodies, provided that some processing is done to eliminate the sulfur. (author)

  9. Numerical simulation of altitude impact on pulverized coal combustion

    Energy Technology Data Exchange (ETDEWEB)

    Pei, Xiaohui; He, Boshu; Ling, Ling; Wang, Lei [Beijing Jiaotong Univ., Beijing (China). Inst. of Mechanical, Electronic and Control Engineering

    2013-07-01

    A drop-tube Furnace simulation model has been developed to investigate the pulverized coal combustion characteristics under different altitudes using the commercially available software Fluent. The altitude conditions of 0, 500, 1,000, 1,500 m have been discussed. The results included the fields of temperature, pressure, velocity, the coal burnout, CO burnout and NO emission in the tube furnace. The variation of these parameters with altitude has been analyzed. The coal combustion characteristics were affected by the altitude. The time and space for coal burnout should be increased with the rise of altitude. The valuable results could be referenced in the design of coal- fired furnaces for the high altitude areas.

  10. Investigation on the transient enthalpy of coal combustion

    Energy Technology Data Exchange (ETDEWEB)

    Fu, Pei-fang; Wang, Na; Yu, Bo; Zhang, Bin; Liu, Yang; Zhou, Huai-chun [Huazhong Univ. of Science and Technology, Wuhan (China). State Key Lab. of Coal Combustion

    2013-07-01

    The transient enthalpy ({Delta}h) of coal/char combustion of the three different coals (including anthracite, bituminous, and lignite) during the process of combustion is determined as a function of burn-off degree by using thermo-gravimetric-differential scanning calorimeter (TG-DSC) simultaneous thermal analyzer, and The error of determining calorific values of coals/chars is less 5% compared the results of TG-DSC with that of an automatic isoperibol calorimeter. It is found that In the initial stage, all the {Delta}h of coals are greater than that of the char pyrolysized from parent coal for many of volatiles contained more a great deal of heat per unit mass oxidized at low temperature, it also imply that coal is more easily ignited than char corresponded; And in the middle stage, all the {Delta}h of coals is lower than that of the char pyrolysized, so the pyrolysized char oxidation can supply much more of thermo-energy per unit mass. {Delta}h are almost a constant when the burn-off degree is equal to between 0.35/0.15 and 0.95/0.85 for ZCY bituminous coal/char and JWY anthracite/char, between 0.35/0.35 and 0.75/0.9 for SLH lignite/char; In the later stage, the {Delta}h of the coal/char decreased with the burn-off degree, it imply that the activity of the coal/char decreases. Therefore, coal pyrolysis changes not only the structure of char, but also the property of release heat; the transient enthalpy of coal/char combustion has been in change with the burn-out degree.

  11. Is coal ash and slag any useful or unloaded wastes?

    International Nuclear Information System (INIS)

    Botezatu, E.; Grecea, C.; Iacob, O.

    2002-01-01

    It is well known that all types of coal, like most materials found in nature, contain trace quantities of the naturally occurring primordial radionuclides (uranium and thorium families and potassium-40). Therefore, the combustion of coal results in partitioning of radionuclides included in the non-combustible mineral matter, between the bottom ash and fly ash, and in the release into the environment of large amounts of coal ash. Emissions from thermal power stations in gaseous and particulate form contain radioisotopes arising from the uranium and thorium series as well as from 4 0K . They are discharged into the environment causing changes in the natural radiation background and radiation exposures to the population. The continued releases of these materials to environment may result in a buildup in the air, water and soil of the radionuclides, particularly radium-226. There will be an increase of the basic radiation rate in the neighborhood area of these plants and consequently relatively higher exposure of the local population to radiation. Coal burning is, therefore, one of the sources of technologically enhanced exposure to humans from natural radionuclides (1,2,3,4,5,6). Coal based thermal power plants constitute about 35% of quantum of energy supply in Romania. In view of the importance of coal for energy supply in Romania, we were interested in knowing possible uses of the resulting wastes and minimize the following harmful consequences of coal burning

  12. GEOTECHNICAL/GEOCHEMICAL CHARACTERIZATION OF ADVANCED COAL PROCESS WASTE STREAMS

    Energy Technology Data Exchange (ETDEWEB)

    Edwin S. Olson; Charles J. Moretti

    1999-11-01

    Thirteen solid wastes, six coals and one unreacted sorbent produced from seven advanced coal utilization processes were characterized for task three of this project. The advanced processes from which samples were obtained included a gas-reburning sorbent injection process, a pressurized fluidized-bed coal combustion process, a coal-reburning process, a SO{sub x}, NO{sub x}, RO{sub x}, BOX process, an advanced flue desulfurization process, and an advanced coal cleaning process. The waste samples ranged from coarse materials, such as bottom ashes and spent bed materials, to fine materials such as fly ashes and cyclone ashes. Based on the results of the waste characterizations, an analysis of appropriate waste management practices for the advanced process wastes was done. The analysis indicated that using conventional waste management technology should be possible for disposal of all the advanced process wastes studied for task three. However, some wastes did possess properties that could present special problems for conventional waste management systems. Several task three wastes were self-hardening materials and one was self-heating. Self-hardening is caused by cementitious and pozzolanic reactions that occur when water is added to the waste. All of the self-hardening wastes setup slowly (in a matter of hours or days rather than minutes). Thus these wastes can still be handled with conventional management systems if care is taken not to allow them to setup in storage bins or transport vehicles. Waste self-heating is caused by the exothermic hydration of lime when the waste is mixed with conditioning water. If enough lime is present, the temperature of the waste will rise until steam is produced. It is recommended that self-heating wastes be conditioned in a controlled manner so that the heat will be safely dissipated before the material is transported to an ultimate disposal site. Waste utilization is important because an advanced process waste will not require

  13. Thermal Behavior of Coal Used in Rotary Kiln and Its Combustion Intensification

    Directory of Open Access Journals (Sweden)

    Qiang Zhong

    2018-04-01

    Full Text Available Pyrolysis and combustion behaviors of three coals (A, B, and C coals were investigated and their combustion kinetics were calculated by the Freeman–Carroll method to obtain quantitative insight into their combustion behaviors. Moreover, the effects of coal size, air flow, oxygen content, and heating rate on coal combustion behaviors were analyzed. Results showed that the three coals have a similar trend of pyrolysis that occurs at about 670 K and this process continuously proceeds along with their combustion. Combustion characteristics and kinetic parameters can be applied to analyze coal combustion behaviors. Three coals having combustion characteristics of suitable ignition temperature (745–761 K, DTGmax (14.20–15.72%/min, and burnout time (7.45–8.10 min were analyzed in a rotary kiln. Combustion kinetic parameters provide quantitative insights into coal combustion behavior. The suitable particle size for coal combustion in a kiln is that the content of less than 74 μm is 60% to 80%. Low activation energy and reaction order make coal, especially C coal, have a simple combustion mechanism, great reactivity, be easily ignited, and a low peak temperature in the combustion state. Oxygen-enrichment and high heating rates enhance coal combustion, increasing combustion intensity and peak value, thus shortening burnout time.

  14. Mercury in coal and the impact of coal quality on mercury emissions from combustion systems

    International Nuclear Information System (INIS)

    Kolker, Allan; Senior, Constance L.; Quick, Jeffrey C.

    2006-01-01

    The proportion of Hg in coal feedstock that is emitted by stack gases of utility power stations is a complex function of coal chemistry and properties, combustion conditions, and the positioning and type of air pollution control devices employed. Mercury in bituminous coal is found primarily within Fe-sulfides, whereas lower rank coal tends to have a greater proportion of organic-bound Hg. Preparation of bituminous coal to reduce S generally reduces input Hg relative to in-ground concentrations, but the amount of this reduction varies according to the fraction of Hg in sulfides and the efficiency of sulfide removal. The mode of occurrence of Hg in coal does not directly affect the speciation of Hg in the combustion flue gas. However, other constituents in the coal, notably Cl and S, and the combustion characteristics of the coal, influence the species of Hg that are formed in the flue gas and enter air pollution control devices. The formation of gaseous oxidized Hg or particulate-bound Hg occurs post-combustion; these forms of Hg can be in part captured in the air pollution control devices that exist on coal-fired boilers, without modification. For a given coal type, the capture efficiency of Hg by pollution control systems varies according to type of device and the conditions of its deployment. For bituminous coal, on average, more than 60% of Hg in flue gas is captured by fabric filter (FF) and flue-gas desulfurization (FGD) systems. Key variables affecting performance for Hg control include Cl and S content of the coal, the positioning (hot side vs. cold side) of the system, and the amount of unburned C in coal ash. Knowledge of coal quality parameters and their effect on the performance of air pollution control devices allows optimization of Hg capture co-benefit

  15. Combustion and emissions characterization of pelletized coal fuels. Technical report, December 1, 1992--February 28, 1993

    Energy Technology Data Exchange (ETDEWEB)

    Rajan, S. [Southern Illinois Univ., Carbondale, IL (United States). Dept. of Mechanical Engineering and Energy Processes

    1993-05-01

    The aim of this project is to demonstrate that sorbent-containing coal pellets made from low grade coal or coal wastes are viable clean burning fuels, and to compare their performance with that of standard run-of-mine coal. Fuels to be investigated are: (a) carbonated pellets containing calcium hydroxide sorbent, (b) coal fines-limestone pellets with cornstarch as binder, (c) pellets made from preparation plant recovered coal containing limestone sorbent and gasification tar as binder, and (d) a standard run-of-mine Illinois seam coal. The fuels will be tested in a laboratory scale 411 diameter circulating fluidized bed combustor. Progress this quarter has centered on the development of a hydraulic press based pellet mill capable of the high compaction pressures necessary to produce the gasification tar containing pellets outlined in (c) above. Limited quantities of the pellets have been made, and the process is being fine tuned before proceeding into the production mode. Tests show that the moisture content of the coal is an important parameter that needs to be fixed within narrow limits for a given coal and binder combination to produce acceptable pellets. Combustion tests with these pellet fuels and the standard coal are scheduled for the next quarter.

  16. NOx emissions from the underfeed combustion of coal and biomass

    International Nuclear Information System (INIS)

    Purvis, M.R.I.; Tadulan, E.L.; Tariq, A.S.

    2000-01-01

    Underfeed stokers have an inherent ability to minimise smoke emissions, thus providing environmental benefits in the combustion of solid fuels, such as biomass materials, which have a high volatile matter content. An evaluation of this attribute requires comparisons of the performance of combustion equipment using these fuels against reference data for coals. However, the recent literature is virtually devoid of studies of coal combustion in underfeed stokers and, in particular, information on nitrogen oxide emissions. In the UK, this reflects a lack of commercial interest in small-scale coal firing due to the wide availability of inexpensive gas and oil fuels. An experimental investigation has been carried out into the combustion of bituminous coal, anthracite and a 50:50 blend by mass of anthracite and oak wood chips on a modified commercial underfeed stoker. The intention was to obtain operational experiences in burning the fuels and reference data for nitrogen oxide emissions. Problems in the combustion of the fuels are described and related to the determination of nitrogen oxide emission values found under optimised plant conditions. These values, expressed at 6% O 2 , were 265 ppm for bituminous coal, 90 ppm for anthracite and 106 ppm for the anthracite/wood chip blend. (Author)

  17. Modelling of NO formation in the combustion of coal blends

    Energy Technology Data Exchange (ETDEWEB)

    Arenillas, A.; Backreedy, R.I.; Jones, J.M.; Pis, J.J.; Pourkashanian, M.; Rubiera, F.; Williams, A. [CSIC, Instituto Nacional del Carbon, Oviedo (Spain)

    2002-03-01

    Coal blending is becoming of increasing importance in power stations firing pulverised coal as a result of increasing competition, stricter emission legislation and is an attractive way of improving plant economic and combustion performance. Presently, the two general methods used by power station operators to assess or predict the performance of an unknown coal blend to be fired in power station boilers are by the use of experimental large scale rig tests or correlation indices derived from experience of firing other coal blends in the power station environment. The first is expensive and the second is of doubtful accuracy in some cases. This paper evaluates the application of mathematical modelling of the combustion of a series of binary coal blends in the test situation of a drop tube reactor to predict the NO emissions and degree of char burnout. Its applicability to low NOx burners used in power stations is discussed and it is concluded that present mathematical coal combustion models are not developed sufficiently to enable an adequate description of the binary blends and the physical and chemical processes, which may include interactions, during combustion of the blend. This means that accurate predictions cannot be made. 20 refs., 4 figs., 5 tabs.

  18. Operational experiences of (in)direct co-combustion in coal and gas fired power plants in Europe

    International Nuclear Information System (INIS)

    Van Ree, R.; Korbee, R.; Meijer, R.; Konings, T.; Van Aart, F.

    2001-02-01

    The operational experiences of direct and indirect co-combustion of biomass/waste in European coal and natural gas fired power plants are addressed. The operational experiences of mainly Dutch direct co-combustion activities in coal fired power plants are discussed; whereas an overview of European indirect co-combustion activities is presented. The technical, environmental, and economic feasibility of different indirect co-combustion concepts (i.e. upstream gasification, pyrolysis, combustion with steam-side integration) is investigated, and the results are compared with the economic preferable concept of direct co-combustion. Main technical constraints that limit the co-combustion capacity of biomass/waste in conventional coal fired power plants are: the grindability of the biomass/coal blend, the capacity of available unit components, and the danger of severe slagging, fouling, corrosion and erosion. The main environmental constraints that have to be taken into account are the quality of produced solid waste streams (fly ash, bottom ash, gypsum) and the applicable air emission regulations. 6 refs

  19. A study of coal-solid waste blend reactivity

    Directory of Open Access Journals (Sweden)

    Nayibe Guerrero

    2008-05-01

    Full Text Available The Flynn-Wall-Ozawa method was used for analysing coal-solid waste blend reactivity in an oxidising atmosphere. The presence of biomass strongly affected coal combustion kinetics when the blend contained more than 30% of it. Activation energy values (evaluated by different blends were 28.7495 kJ/mol for 0% biomass, 31.3915 kJ/mol for 30% biomass, 39.0365 kJ/mol for 50% biomass, 102.431 kJ/mol for 70% biomass and 107.8075 kJ/mol for 100% biomass; these values were close to those reported in the literature. First-order kinetics correlated the data ve-ry well for the 100% coal sample and the blend having 30% biomass and 70% coal. Eighth-order kinetics were more suitable for correlating the experimental data for the 70% biomass-30% coal blend and the 100% biomass sample. Combustion was done without previous pyrolysis of the blends; however segregation of phenomena could be appre-ciated. This seems to indicate that combustion and devolatilisation are independent processes which should be taken into account when building equipment using these kinds of blend.

  20. Automated cost modeling for coal combustion systems

    International Nuclear Information System (INIS)

    Rowe, R.M.; Anast, K.R.

    1991-01-01

    This paper reports on cost information developed at AMAX R and D Center for coal-water slurry production implemented in an automated spreadsheet (Lotus 123) for personal computer use. The spreadsheet format allows the user toe valuate impacts of various process options, coal feedstock characteristics, fuel characteristics, plant location sites, and plant sizes on fuel cost. Model flexibility reduces time and labor required to determine fuel costs and provides a basis to compare fuels manufactured by different processes. The model input includes coal characteristics, plant flowsheet definition, plant size, and market location. Based on these inputs, selected unit operations are chosen for coal processing

  1. Enrichment of trace elements in bottom ash from coal oxy-combustion: Effect of coal types

    CSIR Research Space (South Africa)

    Oboirien, BO

    2016-09-01

    Full Text Available In this study, the enrichment of trace elements in two coals under air and oxy-combustion conditions was studied. Twenty-one trace elements were evaluated. The two coal samples had a different concentration for the 21 trace elements, which was due...

  2. Combustion of coal gas fuels in a staged combustor

    Science.gov (United States)

    Rosfjord, T. J.; Mcvey, J. B.; Sederquist, R. A.; Schultz, D. F.

    1982-01-01

    Gaseous fuels produced from coal resources generally have heating values much lower than natural gas; the low heating value could result in unstable or inefficient combustion. Coal gas fuels may contain ammonia which if oxidized in an uncontrolled manner could result in unacceptable nitrogen oxide exhaust emission levels. Previous investigations indicate that staged, rich-lean combustion represents a desirable approach to achieve stable, efficient, low nitrogen oxide emission operation for coal-derived liquid fuels contaning up to 0.8-wt pct nitrogen. An experimental program was conducted to determine whether this fuel tolerance can be extended to include coal-derived gaseous fuels. The results of tests with three nitrogen-free fuels having heating values of 100, 250, and 350 Btu/scf and a 250 Btu/scf heating value doped to contain 0.7 pct ammonia are presented.

  3. Advanced coal combustion technologies and their environmental impact

    International Nuclear Information System (INIS)

    Bozicevic, Maja; Feretic, Danilo; Tomsic, Zeljko

    1997-01-01

    Estimations of world energy reserves show that coal will remain the leading primary energy source for electricity production in the foreseeable future. In order to comply with ever stricter environmental regulations and to achieve efficient use of limited energy resources, advanced combustion technologies are being developed. The most promising are the pressurised fluidized bed combustion (PFBC) and the integrated gasification combined cycle (IGCC). By injecting sorbent in the furnace, PFBC removes more than 90 percent of SO 2 in flue gases without additional emission control device. In addition, due to lower combustion temperature, NO x emissions are around 90 percent lower than those from pulverised coal (PC) plant. IGCC plant performance is even more environmentally expectable and its high efficiency is a result of a combined cycle usage. Technical, economic and environmental characteristics of mentioned combustion technologies will be presented in this paper. Comparison of PFBC, IGCC and PC power plants economics and air impact will also be given. (Author)

  4. Impacts of heavy metals and radioactivity from coal combustion

    International Nuclear Information System (INIS)

    Goldman, M.

    1977-01-01

    Coal-fueled plants appear to have the potential for a slightly higher radiologic impact on the population than do nuclear-powered plants although in both cases the impact appears to be quite small. The additional impact from trace elements in and on respirable fly ash is of concern and should be factored into the total assessment of potential health consequences associated with a major increase in coal combustion. For some time the paucity of essential data will hamper realistic evaluations

  5. Historical releases of mercury to air, land, and water from coal combustion.

    Science.gov (United States)

    Streets, David G; Lu, Zifeng; Levin, Leonard; Ter Schure, Arnout F H; Sunderland, Elsie M

    2018-02-15

    Coal combustion is one of the largest contemporary sources of anthropogenic mercury (Hg). It releases geologically sequestered Hg to the atmosphere, and fly ash can contaminate terrestrial and aquatic systems. We estimate that coal combustion has released a cumulative total of 38.0 (14.8-98.9, 80% C.I.) Gg (gigagrams, 10 9 g or thousand tonnes) of Hg to air, land, and water up to the year 2010, most of which (97%) has occurred since 1850. The rate of release has grown by two orders of magnitude from 0.01Ggyr -1 in 1850 to 1Ggyr -1 in 2010. Geographically, Asia and Europe each account for 32% of cumulative releases and an additional 18% is from North America. About 26.3 (10.2-68.3) Gg, 71% of the total, were directly emitted to the atmosphere, mostly from the industrial (45%) and power generation (36%) sectors, while the remainder was disposed of to land and water bodies. While Europe and North America were the major contributing regions until 1950, Asia has surpassed both in recent decades. By 2010, Asia was responsible for 69% of the total releases of Hg from coal combustion to the environment. Control technologies installed on major emitting sources capture mainly particulate and divalent Hg, and therefore the fraction of elemental Hg in emissions from coal combustion has increased over time from 0.46 in 1850 to 0.61 in 2010. About 11.8 (4.6-30.6) Gg of Hg, 31% of the total, have been transferred to land and water bodies through the disposal or utilization of Hg-containing combustion waste and collected fly ash/FGD waste; approximately 8.8Gg of this Hg have simply been discarded to waste piles or ash ponds or rivers. Copyright © 2017 Elsevier B.V. All rights reserved.

  6. Characterising the combustion behaviour of New Zealand coals by thermogravimetry

    Energy Technology Data Exchange (ETDEWEB)

    Benfell, K.E.; Beamish, B.B.; Rodgers, K.A. [University of Auckland, Auckland (New Zealand). Dept. of Geology

    1995-12-31

    Thirty-three New Zealand coals were subjected to thermogravimetric analysis (TG) and derivative thermogravimetric analysis (DTG) to evaluate the techniques` applicability to New Zealand coals. Generally, New Zealand sub-bituminous coals have lower burnout temperatures than bituminous coals. However, local and regional differences occur, where some sub-bituminous coals show both higher and lower char burnout temperatures than may be otherwise expected from their rank and T{sub 6} values (the peak temperature where the rate of weight loss of the sample is the greatest). There is a sizeable variations in the char burnout temperature (T{sub 8}) (465 to 636{degree}C) in coals with volatile matter contents above 40%, whereas coals with lower volatile contents have T{sub 8} values around 646{degree}C. The temperature of char burnout gives a better indication of combustion efficiency than rank or volatile matter content alone. Industrial operators could use this technique to provide an indication of burnout performance before a coal is purchased, assisting evaluation of the coal`s suitability for a particular usage. 10 refs., 4 figs., 3 tabs.

  7. 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.

  8. Molten salt combustion of radioactive wastes

    International Nuclear Information System (INIS)

    Grantham, L.F.; McKenzie, D.E.; Richards, W.L.; Oldenkamp, R.D.

    1976-01-01

    The Atomics International Molten Salt Combustion Process reduces the weight and volume of combustible β-γ contaminated transuranic waste by utilizing air in a molten salt medium to combust organic materials, to trap particulates, and to react chemically with any acidic gases produced during combustion. Typically, incomplete combustion products such as hydrocarbons and carbon monoxide are below detection limits (i.e., 3 ) is directly related to the sodium chloride vapor pressure of the melt; >80% of the particulate is sodium chloride. Essentially all metal oxides (combustion ash) are retained in the melt, e.g., >99.9% of the plutonium, >99.6% of the europium, and >99.9% of the ruthenium are retained in the melt. Both bench-scale radioactive and pilot scale (50 kg/hr) nonradioactive combustion tests have been completed with essentially the same results. Design of three combustors for industrial applications are underway

  9. Reactivity and NO emissions of coal blends during combustion

    Energy Technology Data Exchange (ETDEWEB)

    B. Arias; R.I. Backreedy; A. Arenillas; J.M. Jones; F. Rubiera; M. Pourkashanian; A. Williams; J.J. Pis [Instituto Nacional del Carbon, CSIC, Oviedo (Spain)

    2003-07-01

    This work is focussed on burnout and NO emissions during coal blend combustion. Two different approaches were used. In a first step, experimental work was carried out in a laminar entrained flow reactor (EFR) and then computational techniques were applied to improve the burnout prediction of coals and blend during the experiments. A preliminary study on the combustibility of the samples was made using a thermogravimetric analyser. An entrained flow reactor was employed to study the behaviour of coals and blends at high heating rate and short residence times. Burnout and NO emissions were measured during these experiments. Two methods were used to modelling the combustion in the entrained flow reactor: a commercial CFD code and an advanced char burnout model. Experiments done in the EFR showed that burnout and NO emissions of some blends can be predicted from the weighted average of the values of individual coals, especially when blended coals have the same rank. When a blend is made with coals of different rank, some deviations were observed with respect to the averaged values in burnout and especially in NOx emissions. Burnouts predicted with a commercial CFD code were higher than the experimental values. The use of an advanced char burnout model improved greatly the results, showing the advantages of coupling these two mathematical techniques. 9 refs., 7 figs., 2 tabs.

  10. Method and device for the combustion of pulverised coal

    Energy Technology Data Exchange (ETDEWEB)

    Schoppe, F

    1977-01-13

    Until now, high combustion space loadings in pulverised coal firing were only obtained with melting combustion, where the ash is fluid. The disadvantage of this is that part of the heating surface is covered by liquid slack, and this type of combustion cannot operate in 'on-off operation', as the slack solidifies when the boiler is switched off. According to the invention, however, pulverised coal, which is reluctant to react, can be burnt at high combustion space loadings of over 2000 Mcal/cu. metre. hour. atm. with dry ash extraction, so that its use is possible for the combustion in central heating plants in detached houses and blocks of flats, with 'on-off operation'. For this purpose, the pulverised coal is heated under excess pressure in an atmosphere with a maximum of 10% of oxygen with a speed of heating of 1000/sup 0/C/sec up to 100 to 150/sup 0/C above its ignition temperature, and can be blown into the combustion air. Tangentially to the flame jet, a cold gas flow is guided so that burning particles thrown out at the sides are cooled below the ash melting temperature, before they reach the walls. The burning flame jet is accelerated, by using the excess pressure, via an injector, into a zone at less than the ash melting temperature, so that dry ash extraction is guaranteed.

  11. 30 CFR 817.81 - Coal mine waste: General requirements.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 3 2010-07-01 2010-07-01 false Coal mine waste: General requirements. 817.81... ACTIVITIES § 817.81 Coal mine waste: General requirements. (a) General. All coal mine waste disposed of in an... within a permit area, which are approved by the regulatory authority for this purpose. Coal mine waste...

  12. 30 CFR 816.81 - Coal mine waste: General requirements.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 3 2010-07-01 2010-07-01 false Coal mine waste: General requirements. 816.81... ACTIVITIES § 816.81 Coal mine waste: General requirements. (a) General. All coal mine waste disposed of in an... within a permit area, which are approved by the regulatory authority for this purpose. Coal mine waste...

  13. 30 CFR 817.84 - Coal mine waste: Impounding structures.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 3 2010-07-01 2010-07-01 false Coal mine waste: Impounding structures. 817.84... ACTIVITIES § 817.84 Coal mine waste: Impounding structures. New and existing impounding structures constructed of coal mine waste or intended to impound coal mine waste shall meet the requirements of § 817.81...

  14. Coal combustion products in Europe valuable raw materials for the construction industry

    Energy Technology Data Exchange (ETDEWEB)

    Berg, W. vom; Feuerborn, H.J. [European Coal Combustion Products Association e.V., Essen (Germany)

    2005-07-01

    Coal combustion products (CCPs) are formed with the production of electricity in coal-fired power plants. The production of these CCPs has been increased by the years due to legal requirements for flue gas cleaning. The utilisation of CCPS is well is established in some European countries, based on long term experience and technical as well as environmental benefits. As CCPs are defined as waste materials by existing legislation the power industry has to handle the stigma put on the products and hamper the beneficial use. (orig.)

  15. Gaseous emissions during concurrent combustion of biomass and non-recyclable municipal solid waste

    Directory of Open Access Journals (Sweden)

    Oakey John

    2011-02-01

    Full Text Available Abstract Background Biomass and municipal solid waste offer sustainable sources of energy; for example to meet heat and electricity demand in the form of combined cooling, heat and power. Combustion of biomass has a lesser impact than solid fossil fuels (e.g. coal upon gas pollutant emissions, whilst energy recovery from municipal solid waste is a beneficial component of an integrated, sustainable waste management programme. Concurrent combustion of these fuels using a fluidised bed combustor may be a successful method of overcoming some of the disadvantages of biomass (high fuel supply and distribution costs, combustion characteristics and characteristics of municipal solid waste (heterogeneous content, conflict with materials recycling. It should be considered that combustion of municipal solid waste may be a financially attractive disposal route if a 'gate fee' value exists for accepting waste for combustion, which will reduce the net cost of utilising relatively more expensive biomass fuels. Results Emissions of nitrogen monoxide and sulphur dioxide for combustion of biomass are suppressed after substitution of biomass for municipal solid waste materials as the input fuel mixture. Interactions between these and other pollutants such as hydrogen chloride, nitrous oxide and carbon monoxide indicate complex, competing reactions occur between intermediates of these compounds to determine final resultant emissions. Conclusions Fluidised bed concurrent combustion is an appropriate technique to exploit biomass and municipal solid waste resources, without the use of fossil fuels. The addition of municipal solid waste to biomass combustion has the effect of reducing emissions of some gaseous pollutants.

  16. Gaseous emissions during concurrent combustion of biomass and non-recyclable municipal solid waste.

    Science.gov (United States)

    Laryea-Goldsmith, René; Oakey, John; Simms, Nigel J

    2011-02-01

    Biomass and municipal solid waste offer sustainable sources of energy; for example to meet heat and electricity demand in the form of combined cooling, heat and power. Combustion of biomass has a lesser impact than solid fossil fuels (e.g. coal) upon gas pollutant emissions, whilst energy recovery from municipal solid waste is a beneficial component of an integrated, sustainable waste management programme. Concurrent combustion of these fuels using a fluidised bed combustor may be a successful method of overcoming some of the disadvantages of biomass (high fuel supply and distribution costs, combustion characteristics) and characteristics of municipal solid waste (heterogeneous content, conflict with materials recycling). It should be considered that combustion of municipal solid waste may be a financially attractive disposal route if a 'gate fee' value exists for accepting waste for combustion, which will reduce the net cost of utilising relatively more expensive biomass fuels. Emissions of nitrogen monoxide and sulphur dioxide for combustion of biomass are suppressed after substitution of biomass for municipal solid waste materials as the input fuel mixture. Interactions between these and other pollutants such as hydrogen chloride, nitrous oxide and carbon monoxide indicate complex, competing reactions occur between intermediates of these compounds to determine final resultant emissions. Fluidised bed concurrent combustion is an appropriate technique to exploit biomass and municipal solid waste resources, without the use of fossil fuels. The addition of municipal solid waste to biomass combustion has the effect of reducing emissions of some gaseous pollutants.

  17. Field study of wastes from fluidized-bed combustion technologies

    International Nuclear Information System (INIS)

    Weinberg, A.; Holcombe, L.; Butler, R.

    1991-01-01

    The Department of Energy (DOE) has undertaken a research project to monitor advanced coal process wastes placed in natural geologic settings. The overall objective of the study is to gather field data on the engineering and environmental performance of disposed solid waste from various advanced coal processes. The coal ash from a fluidized-bed combustion unit is being studied as part of the DOE program. The unit is a 110-MW circulating fluidized bed (CFB) at Colorado Ute Electric Association's Nucla Steam Electric Station, which is being demonstrated with the support of the DOE Clean Coal Technology Program. The Electric Power Research Institute is cofunding the study. In June of 1989, a test cell approximately 100 feet square and 8 feet deep was constructed and filled with ash from the Colorado Ute CFB unit. The cell was instrumented with lysimeters and neutron probe access tubes to monitor water flow and leachate chemistry in the ash; groundwater wells and runoff collection devices were installed to determine the effects on groundwater and surface water quality, and a meteorological station was installed to determine the water balance. Additionally, tests are being performed to evaluate the chemical, physical, and mineralogical properties of the solid waste and geologic materials. Results from the first year of monitoring are presented

  18. Comparing the greenhouse gas emissions from three alternative waste combustion concepts.

    Science.gov (United States)

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

    2012-03-01

    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. Copyright © 2011 Elsevier Ltd. All rights reserved.

  19. IMPROVED COMBUSTION PROCESSES IN MEDICAL WASTES ...

    African Journals Online (AJOL)

    A small rig was designed for conducting tests on the incineration of rural clinical wastes in Botswana. Experimental results showed that if proper combustion conditions are applied to low technology rural clinical waste incinerators, the operating temperatures could increase from around 400 to above 850oC. It was ...

  20. Method for increasing the calorific value of gas produced by the in situ combustion of coal

    Science.gov (United States)

    Shuck, Lowell Z.

    1978-01-01

    The present invention relates to the production of relatively high Btu gas by the in situ combustion of subterranean coal. The coal bed is penetrated with a horizontally-extending borehole and combustion is initiated in the coal bed contiguous to the borehole. The absolute pressure within the resulting combustion zone is then regulated at a desired value near the pore pressure within the coal bed so that selected quantities of water naturally present in the coal will flow into the combustion zone to effect a hydrogen and carbon monoxide-producing steam-carbon reaction with the hot carbon in the combustion zone for increasing the calorific value of the product gas.

  1. 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.

  2. Selective leaching of coal and coal combustion solid residues

    Energy Technology Data Exchange (ETDEWEB)

    O`Keefe, C.A. [University of North Dakota, Grand Forks, ND (United States). Energy and Environmental Research Center

    1996-12-31

    Selective leaching of coal and fly ash were carried out in order to predict the potential for environmental impact as well as other properties related to the aqueous solubility of inorganic constituents. Chemical fractionation can help to identify the distribution of major, minor, and trace constituents. 35 refs., 10 tabs.

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

    Directory of Open Access Journals (Sweden)

    BORISLAV GRUBOR

    2003-02-01

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

  4. Experimental research on combustion fluorine retention using calcium-based sorbents during coal combustion (II)

    Energy Technology Data Exchange (ETDEWEB)

    Qi, Q.; Ma, X.; Liu, J.; Wu, X.; Zhou, J.; Cen, K. [Liaoning Technical University, Fuxin (China). College of Resource and Environment Engineering

    2008-12-15

    Fluoride pollution produced by coal burning can be controlled with the calcium-based sorbent combustion fluorine technique in which calcium-based sorbents are mixed with the coal or sprayed into the combustion chamber. In a fixed bed tube furnace combustion experiment using one calcium-based natural mineral, limestone and one calcium-based building material, it was shown that the calcium-based sorbent particle grain size and pore structure have a big influence on the combustion fluorine retention effect. Reducing the calcium-based sorbent particle grain size and improving the calcium sorbent structure characteristics at very high temperature to enhance the fluorine retention effect is the important approach to the fluorine retention agent development. 8 refs., 1 fig., 5 tabs.

  5. Combustion modeling in waste tanks

    International Nuclear Information System (INIS)

    Mueller, C.; Unal, C.; Travis, J.R.; Forschungszentrum Karlsruhe

    1997-01-01

    This paper has two objectives. The first one is to repeat previous simulations of release and combustion of flammable gases in tank SY-101 at the Hanford reservation with the recently developed code GASFLOW-II. The GASFLOW-II results are compared with the results obtained with the HMS/TRAC code and show good agreement, especially for non-combustion cases. For combustion GASFLOW-II predicts a steeper pressure rise than HMS/TRAC. The second objective is to describe a so-called induction parameter model which was developed and implemented into GASFLOW-II and reassess previous calculations of Bureau of Mines experiments for hydrogen-air combustion. The pressure time history improves compared with the one-step model, and the time rate of pressure change is much closer to the experimental data

  6. Transformations of inorganic coal constituents in combustion systems

    Energy Technology Data Exchange (ETDEWEB)

    Helble, J.J. (ed.); Srinivasachar, S.; Wilemski, G.; Boni, A.A. (PSI Technology Co., Andover, MA (United States)); Kang, Shin-Gyoo; Sarofim, A.F.; Graham, K.A.; Beer, J.M. (Massachusetts Inst. of Tech., Cambridge, MA (United States)); Peterson, T.W.; Wendt, J.O.L.; Gallagher, N.B.; Bool, L. (Arizona Univ., Tucson, AZ (United States)); Huggins, F.E.; Huffman, G.P.; Shah, N.; Shah, A. (Kentucky Univ., Lexingt

    1992-11-01

    The inorganic constituents or ash contained in pulverized coal significantly increase the environmental and economic costs of coal utilization. For example, ash particles produced during combustion may deposit on heat transfer surfaces, decreasing heat transfer rates and increasing maintenance costs. The minimization of particulate emissions often requires the installation of cleanup devices such as electrostatic precipitators, also adding to the expense of coal utilization. Despite these costly problems, a comprehensive assessment of the ash formation and had never been attempted. At the start of this program, it was hypothesized that ash deposition and ash particle emissions both depended upon the size and chemical composition of individual ash particles. Questions such as: What determines the size of individual ash particles What determines their composition Whether or not particles deposit How combustion conditions, including reactor size, affect these processes remained to be answered. In this 6-year multidisciplinary study, these issues were addressed in detail. The ambitious overall goal was the development of a comprehensive model to predict the size and chemical composition distributions of ash produced during pulverized coal combustion. Results are described.

  7. 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.

  8. Nitrogen Chemistry in Fluidized Bed Combustion of Coal

    DEFF Research Database (Denmark)

    Jensen, Anker Degn

    and reduction by homogeneous and heterogeneous reactions. The data for the estimation of kinetics of the heterogeneous reactions were measured by one of the partners in the project for char and bed material sampled from a pressurized FBC pilot plant burning Kiveton Park coal. Experimental data from the pilot...... plant were used for model verification. The simulations of the NO emission during staged combustion and NH3 injection for NO reduction were in qualitative agreement with the experimental data. A parametric study of the influence of operating conditions on the conversion of fuel-N to NO showed......, the gas interchange coefficient, the bubble size and the bubble rise velocity. The most important combustion parameters were the rate of CO and CH4 combustion and the fraction of CO produced from char combustion. By using a rate of production analysis, the important reactions in the NO model were...

  9. 30 CFR 817.87 - Coal mine waste: Burning and burned waste utilization.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 3 2010-07-01 2010-07-01 false Coal mine waste: Burning and burned waste...-UNDERGROUND MINING ACTIVITIES § 817.87 Coal mine waste: Burning and burned waste utilization. (a) Coal mine... extinguishing operations. (b) No burning or unburned coal mine waste shall be removed from a permitted disposal...

  10. 30 CFR 816.87 - Coal mine waste: Burning and burned waste utilization.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 3 2010-07-01 2010-07-01 false Coal mine waste: Burning and burned waste...-SURFACE MINING ACTIVITIES § 816.87 Coal mine waste: Burning and burned waste utilization. (a) Coal mine... extinguishing operations. (b) No burning or burned coal mine waste shall be removed from a permitted disposal...

  11. Grindability and combustion behavior of coal and torrefied biomass blends.

    Science.gov (United States)

    Gil, M V; García, R; Pevida, C; Rubiera, F

    2015-09-01

    Biomass samples (pine, black poplar and chestnut woodchips) were torrefied to improve their grindability before being combusted in blends with coal. Torrefaction temperatures between 240 and 300 °C and residence times between 11 and 43 min were studied. The grindability of the torrefied biomass, evaluated from the particle size distribution of the ground sample, significantly improved compared to raw biomass. Higher temperatures increased the proportion of smaller-sized particles after grinding. Torrefied chestnut woodchips (280 °C, 22 min) showed the best grinding properties. This sample was blended with coal (5-55 wt.% biomass). The addition of torrefied biomass to coal up to 15 wt.% did not significantly increase the proportion of large-sized particles after grinding. No relevant differences in the burnout value were detected between the coal and coal/torrefied biomass blends due to the high reactivity of the coal. NO and SO2 emissions decreased as the percentage of torrefied biomass in the blend with coal increased. Copyright © 2015 Elsevier Ltd. All rights reserved.

  12. Ultrafine ash aerosols from coal combustion: Characterization and health effects

    Energy Technology Data Exchange (ETDEWEB)

    William P. Linak; Jong-Ik Yoo; Shirley J. Wasson; Weiyan Zhu; Jost O.L. Wendt; Frank E. Huggins; Yuanzhi Chen; Naresh Shah; Gerald P. Huffman; M. Ian Gilmour [US Environmental Protection Agency, Research Triangle Park, NC (United States). National Risk Management Research Laboratory

    2007-07-01

    Ultrafine coal fly-ash particles withdiameters less than 0.5 {mu}m typically comprise less than 1% of the total fly-ash mass. This paper reports research focused on both characterization and health effects of primary ultrafine coal ash aerosols alone. Ultrafine, fine, and coarse ash particles were segregated and collected from a coal burned in a 20 kW laboratory combustor and two additional coals burned in an externally heated drop tube furnace. Extracted samples from both combustors were characterized by transmission electron microscopy (TEM), wavelength dispersive X-ray fluorescence(WD-XRF) spectroscopy, Moessbauer spectroscopy, and X-ray absorption fine structure (XAFS) spectroscopy. Pulmonary inflammation was characterized by albumin concentrations in mouse lung lavage fluid after instillation of collected particles in saline solutions and a single direct inhalation exposure. Results indicate that coal ultrafine ash sometimes contains significant amounts of carbon, probably soot originating from coal tar volatiles, depending on coal type and combustion device. Surprisingly, XAFS results revealed the presence of chromium and thiophenic sulfur in the ultrafine ash particles. The instillation results suggested potential lung injury, the severity of which could be correlated with the carbon (soot) content of the ultrafines. This increased toxicity is consistent with theories in which the presence of carbon mediates transition metal (i.e., Fe) complexes, as revealed in this work by TEM and XAFS spectroscopy, promoting reactive oxygenspecies, oxidation-reduction cycling, and oxidative stress. 24 refs., 7 figs.

  13. Partitioning of elements during coal combustion and leaching experiments

    Energy Technology Data Exchange (ETDEWEB)

    Wang Wen-feng; Qin Yong; Song Dang-yu; Wang Jun-yi [China University of Mining & Technology, Xuzhou (China). School of Resources and Earth Science

    2009-04-15

    The mineral component and content of sulfur and 42 major and trace elements of the feed coal, fly and bottom ashes collected from Shizuishan coal-fired power plant, Ningxia, China were analyzed using AFS, INAA, ICP-MS, ICP-AES, XRD. Based on the coal combustion and leaching experiments, the partitioning of these elements during coal combustion and the leaching behavior of the 11 potentially hazardous elements, including As, Cd, Co, Cr, Hg, Mo, Ni, Pb, Se, Th and U were investigated. The results show that the distribution of elements in the fly and bottom ashes is controlled by their volatilities and modes of occurrence in the coal. The degree of volatilization of elements may be mainly associated with boiling/melting points of these elements and their compounds. The elements easily volatilized, organically bound or associated with sub-micrometer and nano minerals (e.g. Al and Na) tend to be enriched in the fine fractions of fly ash, and most elements do not vaporize which are approximately equally partitioned in the fly and bottom ashes. The emission rates of As, Cr, K, Mg, Mn, Mo, Pb, Sb, and Zn are notably influenced by the temperature ranging from 877 to 1300{sup o}C. The leaching behavior of elements depend significantly on their geochemical properties and modes of occurrence. The elements with a low degree of volatilization are not easily leached, while volatile elements easily leached under the acid conditions. Arsenic, B Br, Cd, Cu, Hg, Pb, S, Sb and Se show a higher emission rate during coal combustion, and the leached concentrations of Cd, Co, Mo, Ni and U in the acid media exceed their limited concentrations recommended in relevant environment quality standards for water, which will harm the environment. 32 refs., 4 figs., 4 tabs.

  14. Pressurized oxy-coal combustion: Ideally flexible to uncertainties

    International Nuclear Information System (INIS)

    Zebian, Hussam; Mitsos, Alexander

    2013-01-01

    Simultaneous multi-variable gradient-based optimization with multi-start is performed on a 300 MWe wet-recycling pressurized oxy-coal combustion process with carbon capture and sequestration, subject to uncertainty in fuel, ambient conditions, and other input specifications. Two forms of flue gas thermal recovery are studied, a surface heat exchanger and a direct contact separation column. Optimization enables ideal flexibility in the processes: when changing the coal utilized, the performance is not compromised compared to the optimum performance of a process specifically designed for that coal. Similarly, the processes are immune to other uncertainties like ambient conditions, air flow, slurry water flow, atomizer stream flow and the oxidizer stream oxygen purity. Consequently, stochastic programming is shown to be unnecessary. Close to optimum design, the processes are also shown to be insensitive towards design variables such as the areas of the feedwater heaters. Recently proposed thermodynamic criteria are used as embedded design specifications in the optimization process, rendering it faster and more robust. - Highlights: • Proposed formulation to assess the flexibility of power generation processes facing uncertainties. • Obtained ideal flexibility of pressurized oxy-coal combustion with respect to coal type. • Performance of processes under uncertainty match performance of optimal processes for specific set of inputs. • Stochastic programming is not required and instead hierarchic optimization is utilized

  15. Wildlife and the coal waste policy debate: proposed rules for coal waste disposal ignore lessons from 45 years of wildlife poisoning

    Science.gov (United States)

    A. Dennis Lemly; Joseph P. Skorupa

    2012-01-01

    This analysis examines wildlife poisoning from coal combustion waste (CCW) in the context of EPA's proposed policy that would allow continued use of surface impoundments as a disposal method. Data from 21 confirmed damage sites were evaluated, ranging from locations where historic poisoning has led to corrective actions that have greatly improved environmental...

  16. The impact of municipal waste combustion in small heat sources

    Science.gov (United States)

    Vantúch, Martin; Kaduchová, Katarína; Lenhard, Richard

    2016-06-01

    At present there is a tendency to make greater use for heating houses for burning solid fuel, such as pieces of wood, coal, coke, local sources of heat to burn natural gas. This tendency is given both the high price of natural gas as well as the availability of cheaper solid fuel. In many cases, in the context saving heating costs, respectively in the context of the disposal of waste is co-incinerated with municipal solid fuels and wastes of different composition. This co entails increased production emissions such as CO (carbon monoxide), NOx (nitrogen oxides), particulate matter (particulate matter), PM10, HCl (hydrogen chloride), PCDD/F (polychlorinated dibenzodioxins and dibenzofurans), PCBs (polychlorinated biphenyls) and others. The experiment was focused on the emission factors from the combustion of fossil fuels in combination with municipal waste in conventional boilers designed to burn solid fuel.

  17. Coal-water slurry fuel internal combustion engine and method for operating same

    Science.gov (United States)

    McMillian, Michael H.

    1992-01-01

    An internal combustion engine fueled with a coal-water slurry is described. About 90 percent of the coal-water slurry charge utilized in the power cycle of the engine is directly injected into the main combustion chamber where it is ignited by a hot stream of combustion gases discharged from a pilot combustion chamber of a size less than about 10 percent of the total clearance volume of main combustion chamber with the piston at top dead center. The stream of hot combustion gases is provided by injecting less than about 10 percent of the total coal-water slurry charge into the pilot combustion chamber and using a portion of the air from the main combustion chamber that has been heated by the walls defining the pilot combustion chamber as the ignition source for the coal-water slurry injected into the pilot combustion chamber.

  18. Evaluation of catalytic combustion of actual coal-derived gas

    Science.gov (United States)

    Blanton, J. C.; Shisler, R. A.

    1982-01-01

    The combustion characteristics of a Pt-Pl catalytic reactor burning coal-derived, low-Btu gas were investigated. A large matrix of test conditions was explored involving variations in fuel/air inlet temperature and velocity, reactor pressure, and combustor exit temperature. Other data recorded included fuel gas composition, reactor temperatures, and exhaust emissions. Operating experience with the reactor was satisfactory. Combustion efficiencies were quite high (over 95 percent) over most of the operating range. Emissions of NOx were quite high (up to 500 ppm V and greater), owing to the high ammonia content of the fuel gas.

  19. TOXIC SUBSTANCES FROM COAL COMBUSTION-A COMPREHENSIVE ASSESSMENT

    Energy Technology Data Exchange (ETDEWEB)

    C.L. Senior; F. Huggins; G.P. Huffman; N. Shah; N. Yap; J.O.L. Wendt; W. Seames; M.R. Ames; A.F. Sarofim; S. Swenson; J.S. Lighty; A. Kolker; R. Finkelman; C.A. Palmer; S.J. Mroczkowski; J.J. Helble; R. Mamani-Paco; R. Sterling; G. Dunham; S. Miller

    2001-06-30

    The Clean Air Act Amendments of 1990 identify a number of hazardous air pollutants (HAPs) as candidates for regulation. Should regulations be imposed on HAP emissions from coal-fired power plants, a sound understanding of the fundamental principles controlling the formation and partitioning of toxic species during coal combustion will be needed. With support from the National Energy Technology Laboratory (NETL), the Electric Power Research Institute, and VTT (Finland), Physical Sciences Inc. (PSI) has teamed with researchers from USGS, MIT, the University of Arizona (UA), the University of Kentucky (UK), the University of Connecticut (UC), the University of Utah (UU) and the University of North Dakota Energy and Environmental Research Center (EERC) to develop a broadly applicable emissions model useful to regulators and utility planners. The new Toxics Partitioning Engineering Model (ToPEM) will be applicable to all combustion conditions including new fuels and coal blends, low-NOx combustion systems, and new power generation plants. Development of ToPEM will be based on PSI's existing Engineering Model for Ash Formation (EMAF). The work discussed in this report covers the Phase II program. Five coals were studied (three in Phase I and two new ones in Phase II). In this work UK has used XAFS and Moessbauer spectroscopies to characterize elements in project coals. For coals, the principal use was to supply direct information about certain hazardous and other key elements (iron) to complement the more complete indirect investigation of elemental modes of occurrence being carried out by colleagues at USGS. Iterative selective leaching using ammonium acetate, HCl, HF, and HNO3, used in conjunction with mineral identification/quantification, and microanalysis of individual mineral grains, has allowed USGS to delineate modes of occurrence for 44 elements. The Phase II coals show rank-dependent systematic differences in trace-element modes of occurrence. The work at

  20. Trace element emissions from spontaneous combustion of gob piles in coal mines, Shanxi, China

    Science.gov (United States)

    Zhao, Y.; Zhang, Jiahua; Chou, C.-L.; Li, Y.; Wang, Z.; Ge, Y.; Zheng, C.

    2008-01-01

    The emissions of potentially hazardous trace elements from spontaneous combustion of gob piles from coal mining in Shanxi Province, China, have been studied. More than ninety samples of solid waste from gob piles in Shanxi were collected and the contents of twenty potentially hazardous trace elements (Be, F, V, Cr, Mn, Co, Ni, Cu, Zn, As, Se, Mo, Cd, Sn, Sb, Hg, Tl, Pb, Th, and U) in these samples were determined. Trace element contents in solid waste samples showed wide ranges. As compared with the upper continental crust, the solid waste samples are significantly enriched in Se (20x) and Tl (12x) and are moderately enriched in F, As, Mo, Sn, Sb, Hg, Th, and U (2-5x). The solid waste samples are depleted in V, Cr, Mn, Co, Ni, Cu, and Zn. The solid waste samples are enriched in F, V, Mn, Cr, Co, Ni, Cu, Zn, Sb, Th, and U as compared with the Shanxi coals. Most trace elements are higher in the clinker than in the unburnt solid waste except F, Sn, and Hg. Trace element abundances are related to the ash content and composition of the samples. The content of F is negatively correlated with the ash content, while Pb is positively correlated with the ash. The concentrations of As, Mn, Zn, and Cd are highly positively correlated with Fe2O3 in the solid waste. The As content increases with increasing sulfur content in the solid waste. The trace element emissions are calculated for mass balance. The emission factors of trace elements during the spontaneous combustion of the gobs are determined and the trace element concentrations in the flue gas from the spontaneous combustion of solid waste are calculated. More than a half of F, Se, Hg and Pb are released to the atmosphere during spontaneous combustion. Some trace element concentrations in flue gas are higher than the national emission standards. Thus, gob piles from coal mining pose a serious environmental problem. ?? 2007 Elsevier B.V. All rights reserved.

  1. Mercury speciation in air-coal and oxy-coal combustion

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Hui; Duan, Yufeng; Mao, Yongqiu [Southeast Univ., Nanjing (China). School of Energy and Environment

    2013-07-01

    To study the effect of air-coal and oxy-coal combustion on mercury emission, Xuzhou bituminous coal was burnt in a 6 kWth fluidized bed at 800 and 850 C in four atmospheres: air, 21%O{sub 2}/79%CO{sub 2}, 30%O{sub 2}/70%CO{sub 2}, 40%O{sub 2}/60%CO{sub 2} analysed with an online flue gas analyzer. Ontario Hydro method (OHM) was employed to measure mercury speciation in flue gas. The result indicated that more elemental mercury and oxidized mercury are released when burned in O{sub 2}/CO{sub 2} atmosphere than in air at 800 C, while the situation is just opposite, when coal was burnt at 850 C, less Hg{sup 0} and Hg{sup 2+} in O{sub 2}/CO{sub 2} atmosphere than in air. The concentration of Hg{sup 0} rises as temperature increases both in the conditions of the air combustion and oxy-coal combustion, but the concentration of Hg{sup 2+} increases with the increase of temperature only in the condition of air combustion and decreases in the oxy-coal combustion. With the increase of the oxygen concentration which is in the range of 21-40%, the concentrations of Hg{sup 0} and Hg{sup 2+} decrease first and then increase. When excess air coefficient increases, the oxygen content is higher and the vaporization rate of Hg{sup 0} and Hg{sup 2+} decrease.

  2. DEVELOPMENT OF ACTIVATED CARBONS FROM COAL COMBUSTION BY-PRODUCTS

    Energy Technology Data Exchange (ETDEWEB)

    Harold H. Schobert; M. Mercedes Maroto-Valer; Zhe Lu

    2003-09-30

    The increasing role of coal as a source of energy in the 21st century will demand environmental and cost-effective strategies for the use of coal combustion by-products (CCBPs), mainly unburned carbon in fly ash. Unburned carbon is nowadays regarded as a waste product and its fate is mainly disposal, due to the present lack of efficient routes for its utilization. However, unburned carbon is a potential precursor for the production of adsorbent carbons, since it has gone through a devolatilization process while in the combustor, and therefore, only requires to be activated. Accordingly, the principal objective of this work was to characterize and utilize the unburned carbon in fly ash for the production of activated carbons. The unburned carbon samples were collected from different combustion systems, including pulverized utility boilers, a utility cyclone, a stoker, and a fluidized bed combustor. LOI (loss-on-ignition), proximate, ultimate, and petrographic analyses were conducted, and the surface areas of the samples were characterized by N2 adsorption isotherms at 77K. The LOIs of the unburned carbon samples varied between 21.79-84.52%. The proximate analyses showed that all the samples had very low moisture contents (0.17 to 3.39 wt %), while the volatile matter contents varied between 0.45 to 24.82 wt%. The elemental analyses show that all the unburned carbon samples consist mainly of carbon with very little hydrogen, nitrogen, sulfur and oxygen In addition, the potential use of unburned carbon as precursor for activated carbon (AC) was investigated. Activated carbons with specific surface area up to 1075m{sup 2}/g were produced from the unburned carbon. The porosity of the resultant activated carbons was related to the properties of the unburned carbon feedstock and the activation conditions used. It was found that not all the unburned carbon samples are equally suited for activation, and furthermore, their potential as activated carbons precursors could be

  3. Effect of combustion characteristics on wall radiative heat flux in a 100 MWe oxy-coal combustion plant

    Energy Technology Data Exchange (ETDEWEB)

    Park, S.; Ryu, C. [Sungkyunkwan Univ., Suwon (Korea, Republic of). School of Mechanical Engineering; Chae, T.Y. [Sungkyunkwan Univ., Suwon (Korea, Republic of). School of Mechanical Engineering; Korea Institute of Industrial Technology, Cheonan (Korea, Republic of). Energy System R and D Group; Yang, W. [Korea Institute of Industrial Technology, Cheonan (Korea, Republic of). Energy System R and D Group; Kim, Y.; Lee, S.; Seo, S. [Korea Electric Power Research Institute (KEPRI), Daejeon (Korea, Republic of). Power Generation Lab.

    2013-07-01

    Oxy-coal combustion exhibits different reaction, flow and heat transfer characteristics from air-coal combustion due to different properties of oxidizer and flue gas composition. This study investigated the wall radiative heat flux (WRHF) of air- and oxy-coal combustion in a simple hexahedral furnace and in a 100 MWe single-wall-fired boiler using computational modeling. The hexahedral furnace had similar operation conditions with the boiler, but the coal combustion was ignored by prescribing the gas properties after complete combustion at the inlet. The concentrations of O{sub 2} in the oxidizers ranging between 26 and 30% and different flue gas recirculation (FGR) methods were considered in the furnace. In the hexahedral furnace, the oxy-coal case with 28% of O{sub 2} and wet FGR had a similar value of T{sub af} with the air-coal combustion case, but its WRHF was 12% higher. The mixed FGR case with about 27% O{sub 2} in the oxidizer exhibited the WRHF similar to the air-coal case. During the actual combustion in the 100 MWe boiler using mixed FGR, the reduced volumetric flow rates in the oxy-coal cases lowered the swirl strength of the burners. This stretched the flames and moved the high temperature region farther to the downstream. Due to this reason, the case with 30% O{sub 2} in the oxidizers achieved a WRHF close to that of air-coal combustion, although its adiabatic flame temperature (T{sub af}) and WHRF predicted in the simplified hexahedral furnace was 103 K and 10% higher, respectively. Therefore, the combustion characteristics and temperature distribution significantly influences the WRHF, which should be assessed to determine the ideal operating conditions of oxy- coal combustion. The choice of the weighted sum of gray gases model (WSGGM) was not critical in the large coal-fired boiler.

  4. Waste plastics as supplemental fuel in the blast furnace process: improving combustion efficiencies.

    Science.gov (United States)

    Kim, Dongsu; Shin, Sunghye; Sohn, Seungman; Choi, Jinshik; Ban, Bongchan

    2002-10-14

    The possibility of using waste plastics as a source of secondary fuel in a blast furnace has been of recent interest. The success of this process, however, will be critically dependent upon the optimization of operating systems. For instance, the supply of waste plastics must be reliable as well as economically attractive compared with conventional secondary fuels such as heavy oil, natural gas and pulverized coal. In this work, we put special importance on the improvement of the combustibility of waste plastics as a way to enhance energy efficiency in a blast furnace. As experimental variables to approach this target, the effects of plastic particle size, blast temperature, and the level of oxygen enrichment were investigated using a custom-made blast model designed to simulate a real furnace. Lastly, the combustion efficiency of the mixture of waste plastics and pulverized coal was tested. The observations made from these experiments led us to the conclusion that with the increase of both blast temperature and the level of oxygen enrichment, and with a decrease in particle size, the combustibility of waste polyethylene could be improved at a given distance from the tuyere. Also it was found that the efficiency of coal combustion decreased with the addition of plastics; however, the combustion efficiency of mixture could be comparable at a longer distance from the tuyere.

  5. Influence of the microwave irradiation dewatering on the combustion characteristics of Chinese brown coals

    Science.gov (United States)

    Ge, Lichao; Feng, Hongcui; Xu, Chang; Zhang, Yanwei; Wang, Zhihua

    2018-02-01

    This study investigates the influence of microwave irradiation on coal composition, pore structure, coal rank, and combustion characteristics of typical brown coals in China. Results show that the upgrading process significantly decreased the inherent moisture, and increased calorific value and fixed carbon content. After upgrading, pore distribution extended to micropore region, oxygen functional groups were reduced and destroyed, and the apparent aromaticity increased suggesting an improvement in the coal rank. Based on thermogravimetric analysis, the combustion processes of upgraded coals were delayed toward the high temperature region, and the temperatures of ignition, peak and burnout increased. Based on the average combustion rate and comprehensive combustion parameter, the upgraded coals performed better compared with raw brown coals and a high rank coal. In ignition and burnout segments, the activation energy increased but exhibited a decrease in the combustion stage.

  6. Speciation of arsenic in Canadian feed-coal and combustion by-products

    Energy Technology Data Exchange (ETDEWEB)

    F. Goodarzi; F.E. Huggins [Natural Resourses Canada (Canada). Geological Survey of Canada-Calgary Division

    2003-07-01

    It is important to determine the oxidation state of arsenic in coal and coal combustion products, as this is generally the single most critical factor determining the toxicity of this element towards humans. However, the same factor is also important for understanding the volatility and reactions of arsenic forms in combustion and their leachability and mobility in ash-disposal situations. In this work, XAFS spectroscopy has been used to examine the speciation of arsenic in Canadian subbituminous and bituminous feed-coals and their combustion products. The concentration of arsenic in the feed-coals varied from < 2 ppm for subbituminous to 54 ppm for bituminous coals. Significant differences were noted in how arsenic occurs in subbituminous and bituminous coals, but, although such differences might influence the initial volatility and reactions of arsenic during coal combustion, arsenic is found almost entirely in the less toxic As{sup 5+} oxidation state in combustion products from both types of coal. (Abstract only)

  7. Naturally Occurring Radioactive Materials in Uranium-Rich Coals and Associated Coal Combustion Residues from China.

    Science.gov (United States)

    Lauer, Nancy; Vengosh, Avner; Dai, Shifeng

    2017-11-21

    Most coals in China have uranium concentrations up to 3 ppm, yet several coal deposits are known to be enriched in uranium. Naturally occurring radioactive materials (NORM) in these U-rich coals and associated coal combustion residues (CCRs) have not been well characterized. Here we measure NORM (Th, U, 228 Ra, 226 Ra, and 210 Pb) in coals from eight U-rich coal deposits in China and the associated CCRs from one of these deposits. We compared NORM in these U-rich coals and associated CCRs to CCRs collected from the Beijing area and natural loess sediments from northeastern China. We found elevated U concentrations (up to 476 ppm) that correspond to low 232 Th/ 238 U and 228 Ra/ 226 Ra activity ratios (≪1) in the coal samples. 226 Ra and 228 Ra activities correlate with 238 U and 232 Th activities, respectively, and 226 Ra activities correlate well with 210 Pb activities across all coal samples. We used measured NORM activities and ash yields in coals to model the activities of CCRs from all U-rich coals analyzed in this study. The activities of measured and modeled CCRs derived from U-rich coals exceed the standards for radiation in building materials, particularly for CCRs originating from coals with U > 10 ppm. Since beneficial use of high-U Chinese CCRs in building materials is not a suitable option, careful consideration needs to be taken to limit potential air and water contamination upon disposal of U- and Ra-rich CCRs.

  8. 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

  9. Role of coal combustion products in sustainable construction materials

    Energy Technology Data Exchange (ETDEWEB)

    Naik, T.R.; Siddique, R.; Vaniker, S. [University of Wisconsin-Milwaukee, Milwaukee, WI (USA). UWM Center for Products Utilization, College of Engineering and Applied Science

    2003-07-01

    The paper describes various coal combustion products, CCPs produced in the process of power generation. These include fly ash, bottom ash, boiler slag and flue gas desulfurization products. Typical test protocol used for testing, analysis and evaluation of CCPs, as well as the current best recycling use options for these materials are discussed. Materials, productions, properties, and potential applications in the manufacture of emerging materials for sustainable construction, as well as environmental impact are also briefly discussed. 47 refs., 16 figs., 8 tabs.

  10. Study experimental of the combustion of coal in grill

    International Nuclear Information System (INIS)

    Chejne j, Farid; Florez E, Whady and others

    1997-01-01

    In this article, experiments in which the temperature of the bed and emissions in the combustion chamber were registered were carried out in pilot plant. Also proximate analyses of coal sizing over the average of unburned carbon was studied in pilot plant and industrial boilers. Finally, graphics of CO vs O2, Nox vs temperature and Sox vs temperature were analyzed in order to determinate their kinetic behavior

  11. Combustion characteristics of intensively cleaned coal fractions. Effect of mineral matter

    Energy Technology Data Exchange (ETDEWEB)

    Rubiera, F.; Arenillas, A.; Fuente, E.; Pis, J.J. [Inst. Nacional de Carbon, Oviedo (Spain); Ivatt, S. [ETSU, Harwell, Didcot (United Kingdom)

    1997-12-31

    The purpose of this work has been to assess the effect that intensive coal cleaning exerts on the combustion behaviour of different density-separated coal fractions. Samples with ash contents varying from 39% for the raw coal, to 2% for the cleanest fraction were obtained after density separation. Temperature-programmed combustion and isothermal gasification in air were used to measure the reactivities of the parent coal and the cleaned fractions. Coal and char reactivities increased with increasing ash content of the samples. Thermal analysis-mass spectrometry of the low-temperature ashes was also carried out in order to study the reactions of coal minerals under combustion conditions. (orig.)

  12. Co-combustion of coal and meat and bone meal

    Energy Technology Data Exchange (ETDEWEB)

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

    2005-12-01

    Feeding meat and bone meal (MBM) to cattle, sheep or other animals has been banned within the EU since 1 of July 1994. The quantities to be eliminated are measured in millions of tons. Disposal to landfill is not an option, as simply burying the material cannot destroy any potential bovine spongiform encephalopathy (BSE) pathogens. One disposal option is the co-combustion of coal and MBM, to ensure that any living organism is totally thermally destroyed and at the same time valorising its energetic potential. Fluidised bed co-combustion of MBM is considered a viable technological option as it has the flexibility to burn coal with different materials in an efficient way, at relatively low temperatures (750-850{sup o}C) with lower environmental impact. For this purpose, co-combustion tests of coal and MBM were carried out on a pilot scale FBC, to investigate the implications of the results. This involved the determination of the emissions of pollutants like NOx, N{sub 2}O, VOC, CO{sub 2}, as well as the composition and the valorisation of the ashes produced. The ashes from the bed, the cyclones and the stack were collected and analyzed for biological activity, ecotoxicity, heavy metal concentration and leachability. The results obtained suggest that the ashes were suitable to be deposited in municipal landfills. 23 refs., 10 figs., 10 tabs.

  13. Influence of Process Parameters on Coal Combustion Performance

    DEFF Research Database (Denmark)

    Lans, Robert Pieter Van Der

    investigated experimentally in a 400 MWe corner fired boiler with over fire air, a 350 MWe opposed fired boiler, and in a 160 kWt pilot scale test rig. Three different coals were fired in each of the furnaces as part of the activities in group 3 of the European Union JOULE 2 Extension project "Atmospheric......The objective of this study is to improve the understanding of nitrogen oxide formation and carbon burnout during the combustion of pulverized coal, and to contribute to addressing the potential of chemical engineering models for the prediction of furnace temperatures, NO emissions and the amount...... of carbon in ash. To this purpose, the effect of coal quality on NO and burnout has been investigated experimentally, a radiation heat balance has been developed based on simple chemical engineering methodology, and a mixing study has been conducted in order to describe the near burner macro mixing in terms...

  14. Coal-char combustion in a fluidised bed reactor

    Energy Technology Data Exchange (ETDEWEB)

    Mehrotra, S.P.; Pande, M. [Indian Institute of Technolgy, Kanpur (India)

    2001-12-01

    Combustion of bituminous coal chars ranging from 0.8 mm to 1.8 mm has been studied in a fluidised bed reactor at temperatures ranging from 500 to 850{sup o}C. The fluidised bed consists of inert sand particles of average size of 0.5 mm and reactive coal char particles. A heat balance has been worked out to calculate the rate of combustion of char from measured incremental changes in the bed temperature during combustion. Investigations on partially burnt particles suggest that the ash layer which builds up around the burning core of char particles is non-flaking and the particles burn in a shrinking core manner. Analysis of rate data indicates that the rate of combustion is controlled by chemical reaction kinetics, though diffusion of oxygen through the bundary layer begins to influence the overall reaction kinetics at higher temperatures. The burnt out time varies linearly with particle size. Activation energy for the chemical reaction control regime is found to be around 68 kJ/mole.

  15. Combustion studies of coal derived solid fuels by thermogravimetric analysis. III. Correlation between burnout temperature and carbon combustion efficiency

    Science.gov (United States)

    Rostam-Abadi, M.; DeBarr, J.A.; Chen, W.T.

    1990-01-01

    Burning profiles of 35-53 ??m size fractions of an Illinois coal and three partially devolatilized coals prepared from the original coal were obtained using a thermogravimetric analyzer. The burning profile burnout temperatures were higher for lower volatile fuels and correlated well with carbon combustion efficiencies of the fuels when burned in a laboratory-scale laminar flow reactor. Fuels with higher burnout temperatures had lower carbon combustion efficiencies under various time-temperature conditions in the laboratory-scale reactor. ?? 1990.

  16. Aspects of combustion behaviour of coals from some New Zealand lignite-coal regions determined by thermogravimetry

    Energy Technology Data Exchange (ETDEWEB)

    Benfell, K.E.; Beamish, B.B.; Rodgers, K.A. [University of Newcastle, Callaghan, NSW (Australia). Dept. of Geology

    1997-08-25

    The papers describes how thermogravimetric analysis of five Late Cretaceous and Cenozoic New Zealand lignites demonstrate that their combustion behaviour is distinct from that of subbituminous coals and may be characterised by peak temperature of 377-416{degree}C, maximum rate of combustion of 25-31 wt% min{sup -1}, and temperature of char burnout 421-497{degree}C. These parameters reflect variation in thermal behaviour associated with both the organic and inorganic constituents of the coal. The information obtained is additional to that provided by proximate analysis; the latter is insufficient to predict the combustion behaviour of the coals relative to one another. A post-combustion thermal event is seen among the lignites as in other low-rank coals combusting below 600{degree}C, which appears to be related to the organic sulphur content of the coal.

  17. Mercury stable isotope signatures of world coal deposits and historical coal combustion emissions.

    Science.gov (United States)

    Sun, Ruoyu; Sonke, Jeroen E; Heimbürger, Lars-Eric; Belkin, Harvey E; Liu, Guijian; Shome, Debasish; Cukrowska, Ewa; Liousse, Catherine; Pokrovsky, Oleg S; Streets, David G

    2014-07-01

    Mercury (Hg) emissions from coal combustion contribute approximately half of anthropogenic Hg emissions to the atmosphere. With the implementation of the first legally binding UNEP treaty aimed at reducing anthropogenic Hg emissions, the identification and traceability of Hg emissions from different countries/regions are critically important. Here, we present a comprehensive world coal Hg stable isotope database including 108 new coal samples from major coal-producing deposits in South Africa, China, Europe, India, Indonesia, Mongolia, former USSR, and the U.S. A 4.7‰ range in δ(202)Hg (-3.9 to 0.8‰) and a 1‰ range in Δ(199)Hg (-0.6 to 0.4‰) are observed. Fourteen (p coal Hg emissions tracing. A revised coal combustion Hg isotope fractionation model is presented, and suggests that gaseous elemental coal Hg emissions are enriched in the heavier Hg isotopes relative to oxidized forms of emitted Hg. The model explains to first order the published δ(202)Hg observations on near-field Hg deposition from a power plant and global scale atmospheric gaseous Hg. Yet, model uncertainties appear too large at present to permit straightforward Hg isotope source identification of atmospheric forms of Hg. Finally, global historical (1850-2008) coal Hg isotope emission curves were modeled and indicate modern-day mean δ(202)Hg and Δ(199)Hg values for bulk coal emissions of -1.2 ± 0.5‰ (1SD) and 0.05 ± 0.06‰ (1SD).

  18. Coal combustion by-products: A survey of use and disposal provisions

    International Nuclear Information System (INIS)

    Jagiella, D.M.

    1993-01-01

    Over 50% of all electricity in the United States is generated by the combustion of coal. Currently, coal fired power plants produce approximately 85 million to 100 million tons of coal combustion byproducts each year. The generation of these byproducts is expected to increase to 120 million tons by the year 2000, an increase of about 72% over 1984 levels. There are four basic types of byproducts produced by coal combustion - fly as, bottom ash, boiler slag, and flue gas desulfurization sludge (FGD), and are useful as engineering materials in a variety of applications. Fly ash represents nearly 75% of all ash wastes generated in the United States. Fly ash is a powder like substance with bonding properties. The properties of fly ash depend on the type of boiler utilized. The collected fly ash can be used to partially replace cement in concrete or the clay tit bricks or as part of nine reclamation. The technology for use of fly ash in cement concrete and road bases is well developed and has been practical for many years. The United States Environmental Protection Agency (USEPA) has recognized the applications of fly ash and promulgated a federal procurement guideline for the use of fly ash in cement and concrete. Although fly ash is the second most widely used waste product, much opportunity remains to expand the use of this product, In 1984, 80% of all fly ash was not recycled but rather disposed of, Ash particles that do not escape in flue gas as fly ash become bottom ash or boiler slag. Bottom ash and boiler slag settles on the bottom of the power plant's boiler. Bottom ash is a sand like substance which has some bonding capability. Depending on the type of boiler, tile bottom ash may be open-quotes dry bottom ashclose quotes or open-quotes wet bottom ashclose quotes, Wet bottom ash falls in a molten state into water

  19. 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.

  20. Numerical simulation of pulverized coal combustion to reduce pollutants

    International Nuclear Information System (INIS)

    Mohammad Bagher Ayani; Behnam Rahmanian

    2010-01-01

    Full text: In this research, the numerical simulation of pollutant reduction and in a pulverized coal combustion at 2D combustion chamber have been studied. Finite volume method using structured grid arrangement was utilized for modeling the pulverized coal combustion. The pressure base algorithm and implicit solver has been employed to simulate non-premix combustion model. The air was diluted by some participative gaseous such as whose percentages varied from 0 % to 20 %. Participative gases and air were preheated by a high-temperature gas generator, and the preheated oxidizer temperature could achieve. The combustion simulation with the generalized finite rate chemistry model, referred to as the Magnussen model and the reacting flow with the mixture fraction PDF/ equilibrium chemistry model, referred to as the PDF model are studied. Quick scheme was adopted for the discretization of all convective terms of the advective transport equations. So, as a result of addition participative gases into oxidizer the rate of formation of pollutants as well as NO x suppressed. The addition only a few percent of halogen components can make some systems nonflammable. The effects of addition halogen components and non-reaction gaseous such as Helium and Argon are fuel dilution and its acts as catalysts in reducing the H atom concentration necessary for the chain branching reaction sequence. Moreover, they act like surface and they make the increment of surface ratio versus volume. Because of this, the number of radical conflicts and hence destruction them will be increase. Furthermore, the rate of formation of pollutants will be decreased if the halogen components and non-reaction gaseous injection will be increased. However, as a result of this research, in the case of injection in pulverized coal combustion the flame temperature is lower than Steam, Argon and Helium. So, the emission levels of carbon dioxide is significantly lower than other participative gases, but in this

  1. Method for processing coal-enrichment waste with solid and volatile fuel inclusions

    Science.gov (United States)

    Khasanova, A. V.; Zhirgalova, T. B.; Osintsev, K. V.

    2017-10-01

    The method relates to the field of industrial heat and power engineering. It can be used in coal preparation plants for processing coal waste. This new way is realized to produce a loose ash residue directed to the production of silicate products and fuel gas in rotary kilns. The proposed method is associated with industrial processing of brown coal beneficiation waste. Waste is obtained by flotation separation of rock particles up to 13 mm in size from coal particles. They have in their composition both solid and volatile fuel inclusions (components). Due to the high humidity and significant rock content, low heat of combustion, these wastes are not used on energy boilers, they are stored in dumps polluting the environment.

  2. CFD simulation of thermodynamic and temperature effects on spontaneous combustion of coal stockpiles and dumps

    CSIR Research Space (South Africa)

    Kekana, J

    2011-01-01

    Full Text Available and energy conservation equations through the porous media. Combustion processes under consideration included physical absorption and desorption of atmospheric species in the coal matrix, formation of coal-oxygen complexes and oxygenated carbon species...

  3. Waste gas combustion in a Hanford radioactive waste tank

    International Nuclear Information System (INIS)

    Travis, J.R.; Fujita, R.K.; Spore, J.W.

    1994-01-01

    It has been observed that a high-level radioactive waste tank generates quantities of hydrogen, ammonia, nitrous oxide, and nitrogen that are potentially well within flammability limits. These gases are produced from chemical and nuclear decay reactions in a slurry of radioactive waste materials. Significant amounts of combustible and reactant gases accumulate in the waste over a 110- to 120-d period. The slurry becomes Taylor unstable owing to the buoyancy of the gases trapped in a matrix of sodium nitrate and nitrite salts. As the contents of the tank roll over, the generated waste gases rupture through the waste material surface, allowing the gases to be transported and mixed with air in the cover-gas space in the dome of the tank. An ignition source is postulated in the dome space where the waste gases combust in the presence of air resulting in pressure and temperature loadings on the double-walled waste tank. This analysis is conducted with hydrogen mixing studies HMS, a three-dimensional, time-dependent fluid dynamics code coupled with finite-rate chemical kinetics. The waste tank has a ventilation system designed to maintain a slight negative gage pressure during normal operation. We modeled the ventilation system with the transient reactor analysis code (TRAC), and we coupled these two best-estimate accident analysis computer codes to model the ventilation system response to pressures and temperatures generated by the hydrogen and ammonia combustion

  4. Soot, organics, and ultrafine ash from air- and oxy-fired coal combustion

    Data.gov (United States)

    U.S. Environmental Protection Agency — Pulverized bituminous coal was burned in a 10W externally heated entrained flow furnace under air-combustion and three oxy-combustion inlet oxygen conditions (28,...

  5. Environmental benefits and drawbacks of composite fuels based on industrial wastes and different ranks of coal.

    Science.gov (United States)

    Nyashina, G S; Vershinina, K Yu; Dmitrienko, M A; Strizhak, P A

    2018-04-05

    A promising solution to many problems that thermal power industry is facing today would be switching from conventional coal dust combustion to coal-water slurries containing petrochemicals (CWSP). Here, we perform an experimental study of the most hazardous anthropogenic emissions (sulfur and nitrogen oxides) from the combustion of high-potential CWSP. We identify the main benefits and potential drawbacks of using CWSP in thermal power industry. A set of components and additives to CWSP are explored that significantly affect the environmental and energy performance of fuels. The anthropogenic emissions from the combustion of CWSP made of widespread coal and oil processing wastes are no higher than those from coal dust combustion. Using specialized additives to CWSP, we can change the concentrations of NO x and SO x several times. The most appealing additives to CWSP are sawdust, straw, charcoal, limestone, and glycerol. They provide better environmental, economic, and energy performance and improve the rheological properties of CWSP. Waste oils and oil sludge added to CWSP may impair the environmental performance but boost the cost and energy efficiency. Using coal-water slurries containing petrochemicals as a fuel at thermal power plants is an environmentally friendly as well as cost- and energy-efficient way to recover industrial wastes. Copyright © 2018 Elsevier B.V. All rights reserved.

  6. OxyFuel combustion of Coal and Biomass

    DEFF Research Database (Denmark)

    Toftegaard, Maja Bøg

    The power and heat producing sector is facing a continuously increasing demand to reduce its emissions of CO2. Oxyfuel combustion combined with CO2 storage is suggested as one of the possible, promising technologies which will enable the continuous use of the existing fleet of suspension-fired po......The power and heat producing sector is facing a continuously increasing demand to reduce its emissions of CO2. Oxyfuel combustion combined with CO2 storage is suggested as one of the possible, promising technologies which will enable the continuous use of the existing fleet of suspension......-fired power plants burning coal or other fuels during the period of transition to renewable energy sources. The oxyfuel combustion process introduces several changes to the power plant configuration. Most important, the main part of the flue gas is recirculated to the boiler and mixed with pure oxygen....... The oxidant thus contains little or no nitrogen and a near-pure CO2 stream can be produced by cooling the flue gas to remove water. The change to the oxidant composition compared to combustion in air will induce significant changes to the combustion process. This Ph.D. thesis presents experimental...

  7. Applying Rock Engineering Systems (RES approach to Evaluate and Classify the Coal Spontaneous Combustion Potential in Eastern Alborz Coal Mines

    Directory of Open Access Journals (Sweden)

    Amir Saffari

    2013-12-01

    Full Text Available Subject analysis of the potential of spontaneous combustion in coal layers with analytical and numerical methods has been always considered as a difficult task because of the complexity of the coal behavior and the number of factors influencing it. Empirical methods, due to accounting for certain and specific factors, have not accuracy and efficiency for all positions. The Rock Engineering Systems (RES approach as a systematic method for analyzing and classifying is proposed in engineering projects. The present study is concerned with employing the RES approach to categorize coal spontaneous combustion in coal regions. Using this approach, the interaction of parameters affecting each other in an equal scale on the coal spontaneous combustion was evaluated. The Intrinsic, geological and mining characteristics of coal seams were studied in order to identifying important parameters. Then, the main stages of implementation of the RES method i.e. interaction matrix formation, coding matrix and forming a list category were performed. Later, an index of Coal Spontaneous Combustion Potential (CSCPi was determined to format the mathematical equation. Then, the obtained data related to the intrinsic, geological and mining, and special index were calculated for each layer in the case study (Pashkalat coal region, Iran. So, the study offers a perfect and comprehensive classification of the layers. Finally, by using the event of spontaneous combustion occurred in Pashkalat coal region, an initial validation for this systematic approach in the study area was conducted, which suggested relatively good concordance in Pashkalat coal region.

  8. 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.

  9. 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.

  10. Partitioning behaviour of natural radionuclides during combustion of coal in thermal power plants

    International Nuclear Information System (INIS)

    Sahu, S.K.; Tiwari, M.; Bhangare, R.C.; Ajmal, P.Y.; Pandit, G.G.

    2014-01-01

    All fossil fuels contain low levels of naturally occurring radioactive substances. The environmental impact of radionuclide-containing waste products from coal combustion is an important issue. These radionuclides vaporize in the hot portions of the coal combustor and then return to the solid phase in cooler downstream zones. Indian coal used in power plants generally has high ash yield (35-45%) and is of low quality. In the burning process of coal, minerals undergo thermal decomposition, fusion, disintegration, and agglomeration. A major portion of elements in the boiler enter into slag or bottom ash, and the rest of the inorganic materials find their way into the flue gas, in fly ash or vapor. Fly and bottom ash are significant sources of exposure to these radionuclides. In the present study, coal and ash samples collected from six thermal power stations were analyzed to determine their natural radioactivity content and the partitioning behavior of these radionuclides was carried out by tracing their activities in fly and bottom ashes. The partitioning of radionuclides is strongly dependent on the size of associated ash particle. Polonium-210 was mostly associated with the finest fraction and showed large variation with particle size whereas 232 Th showed least dependence on the particle size. The high activities of all radionuclides in fly ashes than that of bottom ashes thus may be due to strong affinity of the nuclides towards the finer particle fractions. All the radionuclide distribution favored small particle sizes

  11. 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.

  12. Thermo-optical properties of residential coals and combustion aerosols

    Science.gov (United States)

    Pintér, Máté; Ajtai, Tibor; Kiss-Albert, Gergely; Kiss, Diána; Utry, Noémi; Janovszky, Patrik; Palásti, Dávid; Smausz, Tomi; Kohut, Attila; Hopp, Béla; Galbács, Gábor; Kukovecz, Ákos; Kónya, Zoltán; Szabó, Gábor; Bozóki, Zoltán

    2018-04-01

    In this study, we present the inherent optical properties of carbonaceous aerosols generated from various coals (hard through bituminous to lignite) and their correlation with the thermochemical and energetic properties of the bulk coal samples. The nanoablation method provided a unique opportunity for the comprehensive investigation of the generated particles under well controlled laboratory circumstances. First, the wavelength dependent radiative features (optical absorption and scattering) and the size distribution (SD) of the generated particulate matter were measured in-situ in aerosol phase using in-house developed and customised state-of-the-art instrumentation. We also investigated the morphology and microstructure of the generated particles using Transmission Electron Microscopy (TEM) and Electron Diffraction (ED). The absorption spectra of the measured samples (quantified by Absorption Angström Exponent (AAE)) were observed to be distinctive. The correlation between the thermochemical features of bulk coal samples (fixed carbon (FC) to volatile matter (VM) ratio and calorific value (CV)) and the AAE of aerosol assembly were found to be (r2 = 0.97 and r2 = 0.97) respectively. Lignite was off the fitted curves in both cases most probably due to its high optically inactive volatile material content. Although more samples are necessary to be investigated to draw statistically relevant conclusion, the revealed correlation between CV and Single Scattering Albedo (SSA) implies that climatic impact of coal combusted aerosol could depend on the thermal and energetic properties of the bulk material.

  13. Kinetics of coal combustion: Part 3, Mechanisms and kinetics of char combustion

    Energy Technology Data Exchange (ETDEWEB)

    Gavalas, G. R.; Flagan, R. C. [California Inst. of Tech., Pasadena, CA (USA)

    1988-09-01

    This report summarizes a three-year research program aimed at developing this level of understanding of char combustion through a combination of detailed analysis of chars as produced during devolatilization and as they evolve during oxidation, and theoretical studies of the porous microstructures and of pore diffusion and reaction within the coal particles. A small number of coals have been studied in detail, namely a HVA bituminous (PSOC 1451), a sub-bituminous (PSOC 1488), and a lignite (PSOC 1443). Chars have been generated from size-classified samples of these coals by pyrolysis in an inert atmosphere in a drop tube furnace. The chars were then characterized both chemically and physically. Subsequent oxidation studies were performed on these chars. 42 refs., 54 figs., 4 tabs.

  14. NO emission characteristics of superfine pulverized coal combustion in the O2/CO2 atmosphere

    International Nuclear Information System (INIS)

    Liu, Jiaxun; Gao, Shan; Jiang, Xiumin; Shen, Jun; Zhang, Hai

    2014-01-01

    Highlights: • Superfine pulverized coal combustion in O 2 /CO 2 atmosphere is a new promising technology. • NO emissions of superfine pulverized coal combustion in O 2 /CO 2 mixture were focused. • Coal particle sizes have significant effects on NO emissions in O 2 /CO 2 combustion. - Abstract: The combination of O 2 /CO 2 combustion and superfine pulverized coal combustion technology can make full use of their respective merits, and solve certain inherent disadvantages of each technology. The technology of superfine pulverized coal combustion in the O 2 /CO 2 atmosphere is easy and feasible to be retrofitted with few reconstructions on the existing devices. It will become a useful and promising method in the future. In this paper, a one-dimensional drop-tube furnace system was adopted to study the NO emission characteristics of superfine pulverized coal combustion in the O 2 /CO 2 atmosphere. The effects of coal particle size, coal quality, furnace temperature, stoichiometric ratio, etc. were analyzed. It is important to note that coal particle sizes have significant influence on NO emissions in the O 2 /CO 2 combustion. For the homogeneous NO reduction, smaller coal particles can inhibit the homogeneous NO formations under fuel-rich combustion conditions, while it becomes disadvantageous for fuel-lean combustion. However, under any conditions, heterogeneous reduction is always more significant for smaller coal particle sizes, which have smoother pore surfaces and simpler pore structures. The results from this fundamental research will provide technical support for better understanding and developing this new combustion process

  15. Numerical investigation of heat transfer characteristics in utility boilers of oxy-coal combustion

    International Nuclear Information System (INIS)

    Hu, Yukun; Li, Hailong; Yan, Jinyue

    2014-01-01

    Highlights: • Air-coal and oxy-coal combustion in an industrial scale PF boiler were simulated in ANSYS FLUENT. • The O 2 concentration of 33 vol% in the oxy-coal combustion case matches the air-coal combustion case most closely. • The moisture in the flue gas has little impact on flame temperature, but positive impact on surface incident radiation. - Abstract: Oxy-coal combustion has different flue gas composition from the conventional air-coal combustion. The different composition further results in different properties, such as the absorption coefficient, emissivity, and density, which can directly affect the heat transfer in both radiation and convection zones of utility boilers. This paper numerically studied a utility boiler of oxy-coal combustion and compares with air-coal combustion in terms of flame profile and heat transferred through boiler side walls in order to understand the effects of different operating conditions on oxy-coal boiler retrofitting and design. Based on the results, it was found that around 33 vol% of effective O 2 concentration ([O 2 ] effective ) the highest flame temperature and total heat transferred through boiler side walls in the oxy-coal combustion case match to those in the air-coal combustion case most; therefore, the 33 vol% of [O 2 ] effective could result in the minimal change for the oxy-coal combustion retrofitting of the existing boiler. In addition, the increase of the moisture content in the flue gas has little impact on the flame temperature, but results in a higher surface incident radiation on boiler side walls. The area of heat exchangers in the boiler was also investigated regarding retrofitting. If boiler operates under a higher [O 2 ] effective , to rebalance the load of each heat exchanger in the boiler, the feed water temperature after economizer can be reduced or part of superheating surfaces can be moved into the radiation zone to replace part of the evaporators

  16. Hydrothermal processing of transuranic contaminated combustible waste

    International Nuclear Information System (INIS)

    Buelow, S.J.; Worl, L.; Harradine, D.; Padilla, D.; McInroy, R.

    2001-01-01

    Experiments at Los Alamos National Laboratory have demonstrated the usefulness of hydrothermal processing for the disposal of a wide variety of transuranic contaminated combustible wastes. This paper provides an overview of the implementation and performance of hydrothermal treatment for concentrated salt solutions, explosives, propellants, organic solvents, halogenated solvents, and laboratory trash, such as paper and plastics. Reaction conditions vary from near ambient temperatures and pressure to over 1000degC and 100 MPa pressure. Studies involving both radioactive and non-radioactive waste simulants are discussed. (author)

  17. Transformations of inorganic coal constituents in combustion systems

    Energy Technology Data Exchange (ETDEWEB)

    Helble, J.J. (ed.); Srinivasachar, S.; Wilemski, G.; Boni, A.A. (PSI Technology Co., Andover, MA (United States)); Kang, Shim-Gyoo; Sarofim, A.F.; Graham, K.A.; Beer, J.M. (Massachusetts Inst. of Tech., Cambridge, MA (United States)); Peterson, T.W.; Wendt, O.L.; Gallagher, N.B.; Bool, L. (Arizona Univ., Tucson, AZ (United States)); Huggins, F.E.; Huffman, G.P.; Shah, N.; Shah, A. (Kentucky Univ., Lexington

    1992-11-01

    This report contains the computer codes developed for the coal combustion project. In Subsection B.1 the FORTRAN code developed for the percolative fragmentation model (or the discrete model, since a char is expressed as a collection of discrete elements in a discrete space) is presented. In Subsection B.2 the code for the continuum model (thus named because mineral inclusions are distributed in a continuum space) is presented. A stereological model code developed to obtain the pore size distribution from a two-dimensional data is presented in Subsection B.3.

  18. Catalytic Unmixed Combustion of Coal with Zero Pollution

    Energy Technology Data Exchange (ETDEWEB)

    George Rizeq; Parag Kulkarni; Raul Subia; Wei Wei

    2005-12-01

    GE Global Research is developing an innovative energy-based technology for coal combustion with high efficiency and near-zero pollution. This Unmixed Combustion of coal (UMC-Coal) technology simultaneously converts coal, steam and air into two separate streams of high pressure CO{sub 2}-rich gas for sequestration, and high-temperature, high-pressure vitiated air for producing electricity in gas turbine expanders. The UMC process utilizes an oxygen transfer material (OTM) and eliminates the need for an air separation unit (ASU) and a CO{sub 2} separation unit as compared to conventional gasification based processes. This is the final report for the two-year DOE-funded program (DE-FC26-03NT41842) on this technology that ended in September 30, 2005. The UMC technology development program encompassed lab- and pilot-scale studies to demonstrate the UMC concept. The chemical feasibility of the individual UMC steps was established via lab-scale testing. A pilot plant, designed in a related DOE funded program (DE-FC26-00FT40974), was reconstructed and operated to demonstrate the chemistry of UMC process in a pilot-scale system. The risks associated with this promising technology including cost, lifetime and durability OTM and the impact of contaminants on turbine performance are currently being addressed in detail in a related ongoing DOE funded program (DE-FC26-00FT40974, Phase II). Results obtained to date suggest that this technology has the potential to economically meet future efficiency and environmental performance goals.

  19. Temporal measurements and kinetics of selenium release during coal combustion and gasification in a fluidized bed

    International Nuclear Information System (INIS)

    Shen, Fenghua; Liu, Jing; Zhang, Zhen; Yang, Yingju

    2016-01-01

    Highlights: • The temporal release of Se from coal combustion and gasification was measured. • Kinetic laws for Se release from coal combustion and gasification were determined. • The influences of temperature and chemical composition of flue gas were clarified. • The interactions of Se species with mineral affect the release kinetics of Se. - Abstract: The temporal release of selenium from coal during combustion and gasification in a fluidized bed was measured in situ by an on-line analysis system of trace elements in flue gas. The on-line analysis system is based on an inductively coupled plasma optical emission spectroscopy (ICP-OES), and can measure concentrations of trace elements in flue gas quantitatively and continuously. The results of on-line analysis suggest that the concentration of selenium in flue gas during coal gasification is higher than that during coal combustion. Based on the results of on-line analysis, a second-order kinetic law r(x) = 0.94e −26.58/RT (−0.56 x 2 −0.51 x + 1.05) was determined for selenium release during coal combustion, and r(x) = 11.96e −45.03/RT (−0.53 x 2 −0.56 x + 1.09) for selenium release during coal gasification. These two kinetic laws can predict respectively the temporal release of selenium during coal combustion and gasification with an acceptable accuracy. Thermodynamic calculations were conducted to predict selenium species during coal combustion and gasification. The speciation of selenium in flue gas during coal combustion differs from that during coal gasification, indicating that selenium volatilization is different. The gaseous selenium species can react with CaO during coal combustion, but it is not likely to interact with mineral during coal gasification.

  20. 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.

  1. Influence of Environmentally Friendly and High-Efficiency Composite Additives on Pulverized Coal Combustion in Cement Industry

    Directory of Open Access Journals (Sweden)

    Zhiyong Wang

    2016-01-01

    Full Text Available 4 kinds of chemical reagents and 3 kinds of industrial wastes were selected as burning additives for 2 kinds of coals in cement industry. The work focused on the replacement of partial chemical reagents by industrial wastes, which not only reduced the cost and took full advantage of industrial wastes, but also guaranteed the high combustion efficiency and removed the NOX and SO2 simultaneously. The experiments were carried out in DTF. The combustion residues were analyzed by SEM and XRD. The results showed that the burnout rate was increased after adding the additives; meanwhile, the NOX and SO2 release concentration were reduced, but the degree of action varied for different additives and coals. The substitute of chemical reagents by industrial wastes was very effective; overall, the cold-rolled iron oxide worked better than others; the particles surface was tougher and the peaks of crystalline phase were lower than raw coal, which indicated that the additives played good roles in combustion process.

  2. Co-firing coal and hospital waste in a circulating fluidized bed boiler

    International Nuclear Information System (INIS)

    Coulthard, E.J.; Korenberg, J.; Oswald, K.D.

    1991-01-01

    The Department of Energy - Morgantown Energy Technology Center and the Pennsylvania Energy Development Authority are co-funding a project which will demonstrate the reduction of infectious hospital waste to an environmentally safe disposable ash by cofiring the waste with coal in a circulating fluidized bed (CFB). The main objective of this paper is increased utilization of coal but the project also provides a solution to a problem which has grown rapidly and become very visible in recent years (e.g., hospital waste washed up on beaches). The application of CFB boilers in hospitals introduces an economical clean coal technology into a size range and market dominated by gas and oil combustion systems. The use of CFB represents the utilization of state-of-the-art technology for burning coal in an environmentally benign manner. SO 2 , NO x , CO and particulate emissions lower than the latest New Source Performance Standards have proven to be achievable in CFB combustion systems. By processing the infectious waste in a steam generation system which operates continuously, the problem of creating excessive gaseous emissions during repeated start-ups (as is the case with current incinerator technology) is avoided. The operating conditions with respect to residence time, temperature and turbulence that are inherent to a CFB combustion system, provide an excellent environment for complete combustion and destruction of potentially hazardous solid and gaseous emissions (e.g., dioxins). The limestone, which is injected into the combustion system to reduce SO 2 emissions, will also react with chlorine. Thus chlorine compound emissions and the corrosive nature of the flue gas are reduced. The work efforts to date indicate that infectious waste thermal processing in a coal-fired CFB is a technically and economically viable on-site disposal option

  3. Influence of the hydrothermal dewatering on the combustion characteristics of Chinese low-rank coals

    International Nuclear Information System (INIS)

    Ge, Lichao; Zhang, Yanwei; Xu, Chang; Wang, Zhihua; Zhou, Junhu; Cen, Kefa

    2015-01-01

    This study investigates the influence of hydrothermal dewatering performed at different temperatures on the combustion characteristics of Chinese low-rank coals with different coalification maturities. It was found that the upgrading process significantly decreased the inherent moisture and oxygen content, increased the calorific value and fixed carbon content, and promoted the damage of the hydrophilic oxygen functional groups. The results of oxygen/carbon atomic ratio indicated that the upgrading process converted the low-rank coals near to high-rank coals which can also be gained using the Fourier transform infrared spectroscopy. The thermogravimetric analysis showed that the combustion processes of upgraded coals were delayed toward the high temperature region, and the upgraded coals had higher ignition and burnout temperature. On the other hand, based on the higher average combustion rate and comprehensive combustion parameter, the upgraded coals performed better compared with raw brown coals and the Da Tong bituminous coal. In ignition segment, the activation energy increased after treatment but decreased in the combustion stage. The changes in coal compositions, microstructure, rank, and combustion characteristics were more notable as the temperature in hydrothermal dewatering increased from 250 to 300 °C or coals of lower ranks were used. - Highlights: • Typical Chinese lignites with various ranks are upgraded by hydrothermal dewatering. • Upgraded coals exhibit chemical compositions comparable with that of bituminous coal. • FTIR show the change of microstructure and improvement in coal rank after upgrading. • Upgraded coals exhibit difficulty in ignition but combust easily. • More evident effects are obtained for raw brown coal with relative lower rank.

  4. Mercury emission, control and measurement from coal combustion

    Energy Technology Data Exchange (ETDEWEB)

    Pan, Wei-Ping [North China Electric Power Univ., Beijing (China). School of Energy and Power Engineering; Western Kentucky Univ., Bowling Green, KY (United States). Inst. for Combustion Science and Environmental Technology; Cao, Yan [Western Kentucky Univ., Bowling Green, KY (United States). Inst. for Combustion Science and Environmental Technology; Zhang, Kai [North China Electric Power Univ., Beijing (China). School of Energy and Power Engineering

    2013-07-01

    Coal-fired electric power generation accounts for 65% of U.S. emissions of sulfur dioxide (SO2), 22% of nitrogen oxides (NOx), and 37% of mercury (Hg). The proposed Clear Air Interstate Rule (CAIR) and Clean Air Mercury Rule (CAMR) will attempt to regulate these emissions using a cap-and-trade program to replace a number of existing regulatory requirements that will impact this industry over the next decade. Mercury emissions remain the largest source that has not yet been efficiently controlled, in part because this is one of the most expensive to control. Mercury is a toxic, persistent pollutant that accumulates in the food chain. During the coal combustion process, when both sampling and accurate measurements are challenging, we know that mercury is present in three species: elemental, oxidized and particulate. There are three basic types of mercury measurement methods: Ontario Hydro Method, mercury continuous emission monitoring systems (CEMS) and sorbent-based monitoring. Particulate mercury is best captured by electrostatic precipitators (ESP). Oxidized mercury is best captured in wet scrubbers. Elemental mercury is the most difficult to capture, but selective catalytic reduction units (SCRs) are able to convert elemental mercury to oxidized mercury allowing it to be captured by wet flue gas desulfurization (FGD). This works well for eastern coals with high chlorine contents, but this does not work well on the Wyoming Powder River Basin (PRB) coals. However, no good explanation for its mechanism, correlations of chlorine content in coal with SCR performance, and impacts of higher chlorine content in coal on FGD re-emission are available. The combination of SCR and FGD affords more than an 80% reduction in mercury emissions in the case of high chlorine content coals. The mercury emission results from different coal ranks, boilers, and the air pollution control device (APCD) in power plant will be discussed. Based on this UAEPA new regulation, most power plants

  5. A Reduced Order Model for the Design of Oxy-Coal Combustion Systems

    Directory of Open Access Journals (Sweden)

    Steven L. Rowan

    2015-01-01

    Full Text Available Oxy-coal combustion is one of the more promising technologies currently under development for addressing the issues associated with greenhouse gas emissions from coal-fired power plants. Oxy-coal combustion involves combusting the coal fuel in mixtures of pure oxygen and recycled flue gas (RFG consisting of mainly carbon dioxide (CO2. As a consequence, many researchers and power plant designers have turned to CFD simulations for the study and design of new oxy-coal combustion power plants, as well as refitting existing air-coal combustion facilities to oxy-coal combustion operations. While CFD is a powerful tool that can provide a vast amount of information, the simulations themselves can be quite expensive in terms of computational resources and time investment. As a remedy, a reduced order model (ROM for oxy-coal combustion has been developed to supplement the CFD simulations. With this model, it is possible to quickly estimate the average outlet temperature of combustion flue gases given a known set of mass flow rates of fuel and oxidant entering the power plant boiler as well as determine the required reactor inlet mass flow rates for a desired outlet temperature. Several cases have been examined with this model. The results compare quite favorably to full CFD simulation results.

  6. Soot, organics and ultrafine ash from air- and oxy-fired coal combustion

    Science.gov (United States)

    This paper is concerned with determining the effects of oxy-combustion of coal on the composition of the ultrafine fly ash. To this end, a 10 W externally heated entrained flow furnace was modified to allow the combustion of pulverized coal in flames under practically relevant s...

  7. Combustion behaviour of Sydney and Bowen Basin coals determined by thermogravimetry

    Energy Technology Data Exchange (ETDEWEB)

    Benfell, K.E.; Beamish, B.B.; Rodgers, K.A.; Crosdale, P.J. [University of Auckland, Auckland (New Zealand). Department of Geology

    1996-08-01

    Assesses the suitability of thermogravimetric (TG) and derivative thermogravimetric (DTG) analysis techniques to characterise the combustion behaviour of Sydney and Bowen basin coals. Results indicate that the thermogravimetric technique is suitable for characterising the effects of rank, maceral, sub-maceral and seam variations on the combustion behaviour of these coals. 6 refs., 6 figs., 2 tabs.

  8. 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

  9. Dew point of flue gas in the combustion of brown coal briquettes

    Energy Technology Data Exchange (ETDEWEB)

    Schinkel, W

    1977-08-01

    Economical operation of small steam generators can follow two courses, viz. to channel the emitted gases through the plant and reduce waste gas loss. Two possibilities exist to achieve this: firstly a steam generating process with only slight excess air; secondly a reduction of the emitted gas temperature. The lowest waste gas temperature found in sulphur-containing combustion materials is measured by finding the acid dew-point of the waste gas. The following results in the case of brown coal briquettes were found. Measurements of the dew point of flue gas in two steam generators, both of the double flue type, one having a capacity of 12.5 t/h, the other 25 t/h, one using brown coal briquettes with 1% sulphur content, the other with 3%, resulted in the fact that the dew point can be measured. It was shown that a low air ratio leads to a lowering of the dew point. However this process is unfortunately economically unviable in chain grate generators as the waste gas becomes so thin under a high air ratio that the dew point can only be minimally reduced. Further the acid dew point is only slightly influenced by partial operation of the generator and the infusion of briquette residue.

  10. Effect of multiphase radiation on coal combustion in a pulverized coal jet flame

    International Nuclear Information System (INIS)

    Wu, Bifen; Roy, Somesh P.; Zhao, Xinyu; Modest, Michael F.

    2017-01-01

    The accurate modeling of coal combustion requires detailed radiative heat transfer models for both gaseous combustion products and solid coal particles. A multiphase Monte Carlo ray tracing (MCRT) radiation solver is developed in this work to simulate a laboratory-scale pulverized coal flame. The MCRT solver considers radiative interactions between coal particles and three major combustion products (CO 2 , H 2 O, and CO). A line-by-line spectral database for the gas phase and a size-dependent nongray correlation for the solid phase are employed to account for the nongray effects. The flame structure is significantly altered by considering nongray radiation and the lift-off height of the flame increases by approximately 35%, compared to the simulation without radiation. Radiation is also found to affect the evolution of coal particles considerably as it takes over as the dominant mode of heat transfer for medium-to-large coal particles downstream of the flame. To investigate the respective effects of spectral models for the gas and solid phases, a Planck-mean-based gray gas model and a size-independent gray particle model are applied in a frozen-field analysis of a steady-state snapshot of the flame. The gray gas approximation considerably underestimates the radiative source terms for both the gas phase and the solid phase. The gray coal approximation also leads to under-prediction of the particle emission and absorption. However, the level of under-prediction is not as significant as that resulting from the employment of the gray gas model. Finally, the effect of the spectral property of ash on radiation is also investigated and found to be insignificant for the present target flame. - Highlights: • A Monte Carlo–based nongray radiation solver is developed to study effects of radiation. • Radiation alters the lift-off height, and the distribution of temperature andspecies for the target flame. • Radiation alters the heat transfer mechanism of medium

  11. Influence of inorganic compounds on the combustion of coal. III. The effect of water of constitution of added compounds, moisture, and mineral matter in coal

    Energy Technology Data Exchange (ETDEWEB)

    Newall, H F

    1939-01-01

    The effects on the combustion rate from excess moisture and the addition of selected inorganic substances to powdered coals were determined. The catalytic effect of 19 known inorganic ash constituents on combustion rates was also examined. Alumina and silica were found to inhibit combustion while ferric oxide accelerated it. Titanium, Ge, and B oxides, along with gypsum and calcium phosphate, decreased the rate of combusion, while Ca, Mg, Mn, and V oxides increased combustion rates. Although several of the ash constituents in coal directly affected combustion rates, the effect of adding them to the coal prior to combustion did not correlate with the effect of the mineral matter already in the coal.

  12. The combustion of coal blends in a fluidised bed reactor

    Energy Technology Data Exchange (ETDEWEB)

    Boavida, Dulce; Abelha, Pedro; Gulyurtlu, Ibrahim; Cabrita, Isabel

    1999-07-01

    Combustion studies of five coals of different origin were carried out in a laboratory scale fluidised bed combustor. Five blends prepared by mixing two coals based on their petrological characterisation, in varying amounts, were selected to study the possibility of reduction NO{sub x}, N{sub 2}O and SO{sub 2} emissions. The results showed that some blends had the opposite behaviour concerning the release of NO{sub x} and SO{sub 2} in relation to parent coals, and the emissions were higher than expected. The N{sub 2}O amounts observed were, however, in almost all blends tested, lower than predicted values. With some blends, the mixing levels intended to reduce SO{sub 2} were not always found to correspond to those for simultaneous decrease of Nox. Most of the blends studied showed some evidence of interaction between them. Varying the proportion of the blend components was observed to alter the temperatures at which interactions were stronger.

  13. Low temperature oxidation and spontaneous combustion characteristics of upgraded low rank coal

    Energy Technology Data Exchange (ETDEWEB)

    Choi, H.K.; Kim, S.D.; Yoo, J.H.; Chun, D.H.; Rhim, Y.J.; Lee, S.H. [Korea Institute of Energy Research, Daejeon (Korea, Republic of)

    2013-07-01

    The low temperature oxidation and spontaneous combustion characteristics of dried coal produced from low rank coal using the upgraded brown coal (UBC) process were investigated. To this end, proximate properties, crossing-point temperature (CPT), and isothermal oxidation characteristics of the coal were analyzed. The isothermal oxidation characteristics were estimated by considering the formation rates of CO and CO{sub 2} at low temperatures. The upgraded low rank coal had higher heating values than the raw coal. It also had less susceptibility to low temperature oxidation and spontaneous combustion. This seemed to result from the coating of the asphalt on the surface of the coal, which suppressed the active functional groups from reacting with oxygen in the air. The increasing upgrading pressure negatively affected the low temperature oxidation and spontaneous combustion.

  14. Recent advances in the use of synchrotron radiation for the analysis of coal combustion products

    Energy Technology Data Exchange (ETDEWEB)

    Manowitz, B. [Brookhaven National Lab., Upton, NY (United States)

    1995-11-01

    Two major coal combustion problems are the formation and build-up of slag deposits on heat transfer surfaces and the production and control of toxic species in coal combustion emissions. The use of synchrotron radiation for the analysis of coal combustion products can play a role in the better understanding of both these phenomena. An understanding of the chemical composition of such slags under boiler operating conditions and as a function of the mineral composition of various coals is one ultimate goal of this program. The principal constituents in the ash of many coals are the oxides of Si, Al, Fe, Ca, K, S, and Na. The analytical method required must be able to determine the functional forms of all these elements both in coal and in coal ash at elevated temperatures. One unique way of conducting these analyses is by x-ray spectroscopy.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1997-12-31

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

  16. Assessment of the radiation risk following from exploitation of Polish brown coals. Part 1. Brown coal in Polish industry; preparation of the method of determining the concentrations of main natural radioisotopes appearing in brown coal and its combustion products

    International Nuclear Information System (INIS)

    Jasinska, M.; Niewiadomski, T.; Schwabenthan, J.

    1982-01-01

    Poland is rich in deposits of brown coal applicable for large-scale industry. These deposits are estimated at about 13.5.10 9 tons. In the near future, one-half of the electric power produced in Poland will be generated by power plants using brown coal. As a result, the yearly burden of the environment in Poland will amount to about 15.10 6 tons of ashes and slag, and about 0.79.10 6 tons of fly ash emitted into the atmosphere. Concentrations of radioactive elements in wastes following from the use of brown coal may in some cases be as much as 12 times higher that occuring from combustion products of lignite coal. Distribution of these wastes to the environment affects the population, through inhalation of fly-ashes, consumption of radioactively contaminated products and through living in dwellings constructed of building materials produced using industrial wastes. In order to determine the concentrations of 226 Ra, 232 Th and 40 K in brown coal and in products of its combustion, the method of identifying these elements through gamma-spectrometry has been prepared. Concentrations of 210 Pb and 210 Po will be determined using the method of electrodeposition on metallic silver, which has been tested in the laboratory. (author)

  17. Volcanic ash in feed coal and its influence on coal combustion products

    Energy Technology Data Exchange (ETDEWEB)

    Brownfield, M.E.; Affolter, R.H.; Cathcart, J.D.; Brownfield, I.K.; Hower, J.C.; Stricker, G.D.; O' Connor, J.T.

    2000-07-01

    The US Geological Survey and the University of Kentucky Center for Applied Energy Research are collaborating with an Indiana Utility to determine the physical and chemical properties of feed coal and coal combustion products (CCPs) from a coal-fired power plant. The plant utilizes a low-sulfur (.23--.47 weight percent S) coal from the Powder River Basin, Wyoming. Scanning Electron Microscope (SEM) and X-ray diffraction (XRD) analysis of feed coal samples identified two mineral suites. A primary suite (not authigenic) consisting of quartz (detrital and volcanic beta-form grains), biotite, and minor zircon and a secondary authigenic mineral suite containing calcite, alumino-phosphates (crandallite and gorceixite), kaolinite, quartz, anatase, barite, and pyrite. The authigenic minerals are attributed to air-fall and reworked volcanic ash that was deposited in peat-forming mires. The Powder River Basin feed coals contain higher amounts of Ba, Ca, Mg, Na, Sr, and P compared to other analyzed eastern coals. These elements are associated with alumino-phosphate, biotite, calcite, and clay minerals. The element associations are indicative of coal that incorporated volcanic ash during deposition. XRD analysis of CCPs revealed a predominance of glass, perovskite, lime, gehlenite, quartz, and phosphates with minor amounts of periclase, anhydrite, hematite, and spinel group minerals in the fly ash; and quartz, plagioclase (albite and anorthite), pyroxene (augite and fassaite), rhodonite, and akermanite in the bottom ash. Microprobe and SEM analysis of fly ash samples revealed quartz, zircon, monazite, euhedral laths of corundum with merrillite, hematite, dendritic spinels/ferrites, and rounded grains of wollastonite with periclase. The abundant Ca and Mg mineral phases in the fly ashes are related to the presence of carbonate, clay, and phosphate minerals in the feed coal. The Ca- and Mg-rich mineral phases in the CCPs can be attributed to volcanic minerals deposited in the

  18. 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.)

  19. Monitoring temperatures in coal conversion and combustion processes via ultrasound

    Science.gov (United States)

    Gopalsami, N.; Raptis, A. C.; Mulcahey, T. P.

    1980-02-01

    The state of the art of instrumentation for monitoring temperatures in coal conversion and combustion systems is examined. The instrumentation types studied include thermocouples, radiation pyrometers, and acoustical thermometers. The capabilities and limitations of each type are reviewed. A feasibility study of the ultrasonic thermometry is described. A mathematical model of a pulse-echo ultrasonic temperature measurement system is developed using linear system theory. The mathematical model lends itself to the adaptation of generalized correlation techniques for the estimation of propagation delays. Computer simulations are made to test the efficacy of the signal processing techniques for noise-free as well as noisy signals. Based on the theoretical study, acoustic techniques to measure temperature in reactors and combustors are feasible.

  20. Studies of MHD generator performance with oxygen enriched coal combustion

    Science.gov (United States)

    Wormhoudt, J.; Yousefian, V.; Kolb, C. E.; Martinez-Sanchez, M.

    1980-07-01

    This paper presents calculations made using the Aerodyne PACKAGE (Plasma Analysis, Chemical Kinetics, and Generator Efficiency) computer code which bear on two questions which arise in connection with choices between oxygen enrichment and air preheating to attain the high combustion temperatures needed for open-cycle, coal-fired MHD power generation. The first question is which method produces the highest enthalpy extraction per unit channel length. The second is, in test facilities intended to study tradeoffs between oxygen enrichment and preheated air, can good generator performance be obtained from the same physical channel for different combustor compositions. The answer to the first question is found to depend on what combustor conditions are taken to be comparable. As for the second question, it is found that operation with channel input from off-design combustor conditions can cause serious problems, which can be partially alleviated by changing the channel load factors.

  1. Preparation and combustion of coal-water fuel from the Sin Pun coal deposit, southern Thailand

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-05-01

    In response to an inquiry by the Department of Mineral Resources in Thailand, the Energy & Environmental Research Center (EERC) prepared a program to assess the responsiveness of Sin Pun lignite to the temperature and pressure conditions of hot-water drying. The results indicate that drying made several improvements in the coal, notably increases in heating value and carbon content and reductions in equilibrium moisture and oxygen content. The equilibrium moisture content decreased from 27 wt% for the raw coal to about 15 wt% for the hot-water-dried (HWD) coals. The energy density for a pumpable coal-water fuel (CWF) indicates an increase from 4500 to 6100 Btu/lb by hot-water drying. Approximately 650 lb of HWD Sin Pun CWF were fired in the EERC`s combustion test facility. The fuel burned extremely well, with no feed problems noted during the course of the test. Fouling and slagging deposits each indicated a very low rate of ash deposition, with only a dusty layer formed on the cooled metal surfaces. The combustor was operated at between 20% and 25% excess air, resulting in a flue gas SO{sub 2} concentration averaging approximately 6500 parts per million.

  2. 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.

  3. Toxic substances from coal combustion -- A comprehensive assessment

    Energy Technology Data Exchange (ETDEWEB)

    Senior, C.L.; Huggins, F.E.; Huffman, G.P.; Shan, N.; Yap, N.; Wendt, J.O.L.; Seames, W.; Ames, M.R.; Sarofim, A.F.; Swenson, S.; Lighty, J.; Kolker, A.; Finkelman, R.; Palmer, C.; Mroczkowski, S.; Helble, J.; Mamani-Paco, R.; Sterling, R.; Dunham, G.; Miller, S.

    2000-08-17

    The final program review meeting of Phase II was held on June 22 in Salt Lake City. The goals of the meeting were to present work in progress and to identify the remaining critical experiments or analyses, particularly those involving collaboration among various groups. The information presented at the meeting is summarized in this report. Remaining fixed bed, bench-scale experiments at EERC were discussed. There are more ash samples which can be run. Of particular interest are high carbon ash samples to be generated by the University of Arizona this summer and some ash-derived sorbents that EERC has evaluated on a different program. The use of separation techniques (electrostatic or magnetic) was also discussed as a way to understand the active components in the ash with respect to mercury. XAFS analysis of leached and unleached ash samples from the University of Arizona was given a high priority. In order to better understand the fixed bed test results, CCSEM and Moessbauer analyses of those ash samples need to be completed. Utah plans to analyze the ash from the single particle combustion experiments for those major elements not measured by INAA. USGS must still complete mercury analyses on the whole coals and leaching residues. Priorities for further work at the SHRIMP-RG facility include arsenic on ash surfaces and mercury in sulfide minerals. Moessbauer analyses of coal samples from the University of Utah were completed; samples from the top and bottom layers of containers of five different coals showed little oxidation of pyrite in the top relative to the bottom except for Wyodak.

  4. Mercury emissions from coal combustion in Silesia, analysis using geostatistics

    Science.gov (United States)

    Zasina, Damian; Zawadzki, Jaroslaw

    2015-04-01

    Data provided by the UNEP's report on mercury [1] shows that solid fuel combustion in significant source of mercury emission to air. Silesia, located in southwestern Poland, is notably affected by mercury emission due to being one of the most industrialized Polish regions: the place of coal mining, production of metals, stone mining, mineral quarrying and chemical industry. Moreover, Silesia is the region with high population density. People are exposed to severe risk of mercury emitted from both: industrial and domestic sources (i.e. small household furnaces). Small sources have significant contribution to total emission of mercury. Official and statistical analysis, including prepared for international purposes [2] did not provide data about spatial distribution of the mercury emitted to air, however number of analysis on Polish public power and energy sector had been prepared so far [3; 4]. The distribution of locations exposed for mercury emission from small domestic sources is interesting matter merging information from various sources: statistical, economical and environmental. This paper presents geostatistical approach to distibution of mercury emission from coal combustion. Analysed data organized in 2 independent levels: individual, bottom-up approach derived from national emission reporting system [5; 6] and top down - regional data calculated basing on official statistics [7]. Analysis, that will be presented, will include comparison of spatial distributions of mercury emission using data derived from sources mentioned above. Investigation will include three voivodeships of Poland: Lower Silesian, Opole (voivodeship) and Silesian using selected geostatistical methodologies including ordinary kriging [8]. References [1] UNEP. Global Mercury Assessment 2013: Sources, Emissions, Releases and Environmental Transport. UNEP Chemicals Branch, Geneva, Switzerland, 2013. [2] NCEM. Poland's Informative Inventory Report 2014. NCEM at the IEP-NRI, 2014. http

  5. The Evaluation of Solid Wastes Reduction with Combustion System in the Combustion Chamber

    International Nuclear Information System (INIS)

    Prayitno; Sukosrono

    2007-01-01

    The evaluation of solid wastes reduction with combustion system is used for weight reduction factor. The evaluation was done design system of combustion chamber furnace and the experiment was done by burning a certain weight of paper, cloth, plastic and rubber in the combustion chamber. The evaluation of paper wastes, the ratio of wastes (paper, cloth, plastic and rubber) against the factor of weight reduction (%) were investigated. The condition was dimension of combustion chamber furnace = 0.6 X 0.9 X 1.20 X 1 m with combustion chamber and gas chamber and reached at the wastes = 2.500 gram, oxygen pressure 0.5 Bar, wastes ratio : paper : cloth : plastic : rubber = 55 : 10 : 30 : 5, the reduction factor = 6.36 %. (author)

  6. Combustible radioactive waste treatment by incineration and chemical digestion

    International Nuclear Information System (INIS)

    Stretz, L.A.; Crippen, M.D.; Allen, C.R.

    1980-01-01

    A review is given of present and planned combustible radioactive waste treatment systems in the US. Advantages and disadvantages of various systems are considered. Design waste streams are discussed in relation to waste composition, radioactive contaminants by amount and type, and special operating problems caused by the waste

  7. Carbon and oxygen isotopic composition of coal and carbon dioxide derived from laboratory coal combustion: A preliminary study

    Science.gov (United States)

    Warwick, Peter D.; Ruppert, Leslie F.

    2016-01-01

    The concentration of carbon dioxide (CO2) in the atmosphere has dramatically increased from the start of the industrial revolution in the mid-1700s to present levels exceeding 400 ppm. Carbon dioxide derived from fossil fuel combustion is a greenhouse gas and a major contributor to on-going climate change. Carbon and oxygen stable isotope geochemistry is a useful tool to help model and predict the contributions of anthropogenic sources of CO2 in the global carbon cycle. Surprisingly few studies have addressed the carbon and oxygen isotopic composition of CO2 derived from coal combustion. The goal of this study is to document the relationships between the carbon and oxygen isotope signatures of coal and signatures of the CO2 produced from laboratory coal combustion in atmospheric conditions.Six coal samples were selected that represent various geologic ages (Carboniferous to Tertiary) and coal ranks (lignite to bituminous). Duplicate splits of the six coal samples were ignited and partially combusted in the laboratory at atmospheric conditions. The resulting coal-combustion gases were collected and the molecular composition of the collected gases and isotopic analyses of δ13C of CO2, δ13C of CH4, and δ18O of CO2 were analysed by a commercial laboratory. Splits (~ 1 g) of the un-combusted dried ground coal samples were analyzed for δ13C and δ18O by the U.S. Geological Survey Reston Stable Isotope Laboratory.The major findings of this preliminary work indicate that the isotopic signatures of δ13C (relative to the Vienna Pee Dee Belemnite scale, VPDB) of CO2 resulting from coal combustion are similar to the δ13CVPDB signature of the bulk coal (− 28.46 to − 23.86 ‰) and are not similar to atmospheric δ13CVPDB of CO2 (~ − 8 ‰, see http://www.esrl.noaa.gov/gmd/outreach/isotopes/c13tellsus.html). The δ18O values of bulk coal are strongly correlated to the coal dry ash yields and appear to have little or no influence on the δ18O values of CO2

  8. Co-firing option of palm shell waste and Malaysian coal blends in a circulating fluidized bed

    International Nuclear Information System (INIS)

    Ahmad Hussain; Farid Nasir Ani

    2010-01-01

    Palm oil shell waste is one of the main agriculture wastes in Malaysia. In order to utilize these wastes efficiently, pyrolysis of oil-palm shell waste was first carried out using Thermogravimetric analysis (TGA). The effects of heating rate on the pyrolytic properties were investigated to evaluate its suitability for co-firing. The TGA analyses of oil palm shell waste and Malaysian coal blends suggests that there is an obvious lateral shift in the thermo grams for different heating rate. Kinetics calculations were also done using integral method. For palm shell waste powder it was found that the activation energies ranged from 112-119 kJ/mole and for the Mukah coal blends it ranged from 93.3 -100.8 kJ/mole. Combustion studies for palm shell wastes and coal blends were done in a hot circulating fluidized-bed (CFB) test rig. This is the first practical experience of using this type of rig in Malaysia. The temperature dependence on the combustion and emission behaviour were identified. The effects of variation of primary air and feed rate have also been analyzed and their influence on emissions has been established. The combustion studies of palm shell wastes were done and it was found that the emission of NO x ranged from 20-164 ppm while the CO emissions were high for some operating conditions. For the co-firing studies, the NO x and CO deceased with the percentage increase in the blending ratio of coal with palm shell waste.. The optimum blending ratio was found to be in a ratio of 40 percent coal and 60 percent Mukah coal. It was also found that Mukah coal show agglomeration behaviour with when it is blended in 80% ratio. (author)

  9. 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.)

  10. Coal waste management practices in the USA:an overview

    Institute of Scientific and Technical Information of China (English)

    Yoginder P. Chugh; Paul T. Behum

    2014-01-01

    This paper provides an overview of coal waste management practices with two case studies and an estimate of management cost in 2010 US dollars. Processing of as-mined coal typically results in considerable amount of coarse and fine coal processing wastes because of in-seam and out-of-seam dilution mining. Processing plant clean coal recovery values run typically 50%–80%. Trace metals and sulfur may be present in waste materials that may result in leachate water with corrosive charac-teristics. Water discharges may require special measures such as liner and collection systems, and treatment to neutralize acid drainage and/or water quality for trace elements. The potential for variations in coal waste production and quality depends upon mining or processing, plus the long-term methods of waste placement. The changes in waste generation rates and engineering properties of the coal waste during the life of the facility must be considered. Safe, economical and environmentally acceptable management of coal waste involves consideration of geology, soil and rock mechanics, hydrology, hydraulics, geochemistry, soil science, agronomy and environmental sciences. These support all aspects of the regulatory environment including the design and construction of earth and rock embankments and dams, as well as a wide variety of waste disposal structures. Development of impoundments is critical and require considerations of typical water-impounding dams and additional requirements of coal waste disposal impoundments. The primary purpose of a coal waste disposal facility is to dispose of unusable waste materials from mining. However, at some sites coal waste impoundments serve to provide water storage capacity for processing and flood attenuation.

  11. Aqueous clay suspensions stabilized by alginate fluid gels for coal spontaneous combustion prevention and control.

    Science.gov (United States)

    Qin, Botao; Ma, Dong; Li, Fanglei; Li, Yong

    2017-11-01

    We have developed aqueous clay suspensions stabilized by alginate fluid gels (AFG) for coal spontaneous combustion prevention and control. Specially, this study aimed to characterize the effect of AFG on the microstructure, static and dynamic stability, and coal fire inhibition performances of the prepared AFG-stabilized clay suspensions. Compared with aqueous clay suspensions, the AFG-stabilized clay suspensions manifest high static and dynamic stability, which can be ascribed to the formation of a robust three-dimensional gel network by AFG. The coal acceleration oxidation experimental results show that the prepared AFG-stabilized clay suspensions can improve the coal thermal stability and effectively inhibit the coal spontaneous oxidation process by increasing crossing point temperature (CPT) and reducing CO emission. The prepared low-cost and nontoxic AFG-stabilized clay suspensions, exhibiting excellent coal fire extinguishing performances, indicate great application potentials in coal spontaneous combustion prevention and control.

  12. Latest developments in the utilization of coal mining wastes

    Energy Technology Data Exchange (ETDEWEB)

    Canibano, J G [HUNOSA, Oviedo (Spain)

    1996-12-31

    This report summarizes recent studies carried out on coal mining wastes (minestones) of Spain. These studies proved that such wastes can be used as filling materials in reinforced earth structures, capping layers of roads, substratum in hydroponic cultures and fuel.

  13. 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

  14. Disposal and reclamation of southwestern coal and uranium wastes

    International Nuclear Information System (INIS)

    Wewerka, E.M.

    1979-01-01

    The types of solid wastes and effluents produced by the southwestern coal and uranium mining and milling industries are considered, and the current methods for the disposal and reclamation of these materials discussed. The major means of disposing of the solid wastes from both industries is by land fill or in some instances ponding. Sludges or aqueous wastes are normally discharged into settling and evaporative ponds. Basic reclamation measures for nearly all coal and uranium waste disposal sites include solids stabilization, compacting, grading, soil preparation, and revegetation. Impermeable liners and caps are beginning to be applied to disposal sites for some of the more harmful coal and uranium waste materials

  15. A comparison of spontaneous combustion susceptibility of coal from ...

    African Journals Online (AJOL)

    Although the CPT of Onyeama coal and Owukpa coal is identical to each other as they are the sub-bituminous, Owukpa coal has a lower initial oxidation temperature (IOT) and maximum oxidation temperature (MOT) than those of Onyeama coal. This means that although each coal has the same rank and CPT, spontaneous ...

  16. 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

  17. Characterization of Moroccan coal waste: valorization in the elaboration of the Portland clinker

    Directory of Open Access Journals (Sweden)

    Belkheiri D.

    2014-04-01

    Full Text Available Coal exploited in the mine of Jerada (northeast of Morocco was accompanied by large quantities of waste. The purpose of this work is to characterize this waste with the aim of its use as a material for civil engineering. Mineral and chemical investigations on this waste in the raw state, and at different temperature of heat treatments, were carried out by various methods: X-ray fluorescence, X-ray diffraction, infrared spectroscopy. These analyzes showed that the studied waste, contain essentially a mineral part formed by silica and various clays, as well as coal’s residues. The thermal investigation of waste, by differential scanning calorimetry (DSC, revealed an exothermic phenomenon attributed to the combustion of coal residues. Other phenomena were noted on the thermograms due to the mineral part transformations. In this analysis a comparison was also made with pure coal. These characteristics of coal waste encourage studying its development in reducing energy consumption in the Portland cement manufacture. Mixtures of waste with limestone or with raw cement materials were studied, and the resulting products were analyzed by different methods.

  18. Electrically fired incineration of combustible radioactive waste

    International Nuclear Information System (INIS)

    Charlesworth, D.; Hill, M.

    1985-01-01

    Du Pont Company and Shirco, Inc. are developing a process to incinerate plutonium-contaminated combustible waste in an electrically fired incineration system. Preliminary development was completed at Shirco, Inc. prior to installing an incineration system at the Savannah River Laboratory (SRL), which is operated by Du Pont for the US Department of Energy (DOE). The waste consists of disposable protective clothing, cleaning materials, used filter elements, and miscellaneous materials exposed to plutonium contamination. Incinerator performance testing, using physically representative nonradioactive materials, was completed in March 1983 at Shirco's Pilot Test Facility in Dallas, TX. Based on the test results, equipment sizing and mechanical begin of a full-scale process were completed by June 1983. The full-scale unit is being installed at SRL to confirm the initial performance testing and is scheduled to begin in June 1985. Remote operation and maintenance of the system is required, since the system will eventually be installed in an isolated process cell. Initial operation of the process will use nonradioactive simulated waste. 2 figs., 2 tabs

  19. Effect of coal blending on the leaching characteristics of arsenic and selenium in fly ash from fluidized bed coal combustion

    Energy Technology Data Exchange (ETDEWEB)

    Jiao, F.; Yamada, N.; Sato, A.; Ninomiya, Yoshihiko [Chubu Univ., Aichi (Japan). Dept. of Applied Chemistry; Zhang, L. [Monash Univ., Clayton, VIC (Australia). Dept. of Chemical Engineering

    2013-07-01

    The capture ability of fly ash to arsenic (As) and selenium (Se) was investigated through the combustion of two single bituminous coals A and B and their mixture (blending ratio of 1:1, wt/wt) in a lab-scale fluidized bed reactor. The leaching characteristics of As and Se in corresponding fly ash were also conducted according to Japanese Industrial Standard (JIS). Speciation of As and Se during fly ash leaching test were predicted from the perspective of thermodynamic equilibrium. The results indicate that, combustion of coal B, containing abundant calcium, possesses a higher capture ability of As and Se than that of coal A through possible chemical reaction between As/Se with CaO. Leaching behavior of As and Se from fly ash is strongly dependent on the pH of the leachate. Free calcium in fly ash generates an alkaline leachate during leaching test and subsequently reduces As and Se leaching, which cause the leaching ratio of As and Se in fly ash derived from the combustion of coal B was much lower, relative to that in coal A. Combustion of blending coal promotes the overall capture ability of the fly ash to As/Se and reduces their leaching from fly ash through the synergy of free CaO between this two kind of fly ash.

  20. Coal char combustion under a CO{sub 2}-rich atmosphere: Implications for pulverized coal injection in a blast furnace

    Energy Technology Data Exchange (ETDEWEB)

    Borrego, A.G.; Casal, M.D. [Instituto Nacional del Carbon, CSIC. P.O. Box 73, 33080 Oviedo (Spain); Osorio, E.; Vilela, A.C.F. [Laboratorio de Siderurgia, DEMET/PPGEM - Universidade Federal do Rio Grande do Sul. P.O. Box 15021, 91501-970 Porto Alegre (Brazil)

    2008-11-15

    Pulverized coal injection (PCI) is employed in blast furnace tuyeres attempting to maximize the injection rate without increasing the amount of unburned char inside the stack of the blast furnace. When coal is injected with air through the injection lance, the resolidified char will burn in an atmosphere with a progressively lower oxygen content and higher CO{sub 2} concentration. In this study an experimental approach was followed to separate the combustion process into two distinct devolatilization and combustion steps. Initially coal was injected into a drop tube furnace (DTF) operating at 1300 C in an atmosphere with a low oxygen concentration to ensure the combustion of volatiles and prevent the formation of soot. Then the char was refired into the DTF at the same temperature under two different atmospheres O{sub 2}/N{sub 2} (typical combustion) and O{sub 2}/CO{sub 2} (oxy-combustion) with the same oxygen concentration. Coal injection was also performed under a higher oxygen concentration in atmospheres typical for both combustion and oxy-combustion. The fuels tested comprised a petroleum coke and coals currently used for PCI injection ranging from high volatile to low volatile bituminous rank. Thermogravimetric analyses and microscopy techniques were used to establish the reactivity and appearance of the chars. Overall similar burnouts were achieved with N{sub 2} and CO{sub 2} for similar oxygen concentrations and therefore no loss in burnout should be expected as a result of enrichment in CO{sub 2} in the blast furnace gas. The advantage of increasing the amount of oxygen in a reacting atmosphere during burnout was found to be greater, the higher the rank of the coal. (author)

  1. Coal Combustion Residual Beneficial Use Evaluation: Fly Ash Concrete and FGD Gypsum Wallboard

    Science.gov (United States)

    This page contains documents related to the evaluation of coal combustion residual beneficial use of fly ash concrete and FGD gypsum wallboard including the evaluation itself and the accompanying appendices

  2. Hydrothermal processing of radioactive combustible waste

    International Nuclear Information System (INIS)

    Worl, L.A.; Buelow, S.J.; Harradine, D.; Le, L.; Padilla, D.D.; Roberts, J.H.

    1998-01-01

    Hydrothermal processing has been demonstrated for the treatment of radioactive combustible materials for the US Department of Energy. A hydrothermal processing system was designed, built and tested for operation in a plutonium glovebox. Presented here are results from the study of the hydrothermal oxidation of plutonium and americium contaminated organic wastes. Experiments show the destruction of the organic component to CO 2 and H 2 O, with 30 wt.% H 2 O 2 as an oxidant, at 540 C and 46.2 MPa. The majority of the actinide component forms insoluble products that are easily separated by filtration. A titanium liner in the reactor and heat exchanger provide corrosion resistance for the oxidation of chlorinated organics. The treatment of solid material is accomplished by particle size reduction and the addition of a viscosity enhancing agent to generate a homogeneous pumpable mixture

  3. 30 CFR 816.83 - Coal mine waste: Refuse piles.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 3 2010-07-01 2010-07-01 false Coal mine waste: Refuse piles. 816.83 Section... ACTIVITIES § 816.83 Coal mine waste: Refuse piles. Refuse piles shall meet the requirements of § 816.81, the... drainage may not be diverted over the outslope of the refuse piles. Runoff from the areas above the refuse...

  4. 30 CFR 817.83 - Coal mine waste: Refuse piles.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 3 2010-07-01 2010-07-01 false Coal mine waste: Refuse piles. 817.83 Section... ACTIVITIES § 817.83 Coal mine waste: Refuse piles. Refuse piles shall meet the requirements of § 817.81, the... drainage may not be diverted over the outslope of the refuse pile. Runoff from areas above the refuse pile...

  5. Research and Development of a New Silica-Alumina Based Cementitious Material Largely Using Coal Refuse for Mine Backfill, Mine Sealing and Waste Disposal Stabilization

    Energy Technology Data Exchange (ETDEWEB)

    Henghu Sun; Yuan Yao

    2012-06-29

    Coal refuse and coal combustion byproducts as industrial solid waste stockpiles have become great threats to the environment. To activate coal refuse is one practical solution to recycle this huge amount of solid waste as substitute for Ordinary Portland Cement (OPC). The central goal of this project is to investigate and develop a new silica-alumina based cementitious material largely using coal refuse as a constituent that will be ideal for durable construction, mine backfill, mine sealing and waste disposal stabilization applications. This new material is an environment-friendly alternative to Ordinary Portland Cement. The main constituents of the new material are coal refuse and other coal wastes including coal sludge and coal combustion products (CCPs). Compared with conventional cement production, successful development of this new technology could potentially save energy and reduce greenhouse gas emissions, recycle vast amount of coal wastes, and significantly reduce production cost. A systematic research has been conducted to seek for an optimal solution for enhancing pozzolanic reactivity of the relatively inert solid waste-coal refuse in order to improve the utilization efficiency and economic benefit as a construction and building material.

  6. Three-dimensional simulation of flow and combustion for pulverised coal injection

    Energy Technology Data Exchange (ETDEWEB)

    Guo, B.Y.; Zulli, P.; Rogers, H.; Mathieson, J.G.; Yu, A.B. [BlueScope Steel Research, Port Kembla, NSW (Australia)

    2005-07-01

    A three-dimensional numerical model of pulverised coal injection has been developed for simulating coal flow and combustion in the tuyere and raceway of a blast furnace. The model has been used to simulate previously reported combustion tests, which feature an inclined co-axial lance with an annular cooling gas. The predicted coal burnout agrees well with that measured for three coals with volatile contents and particle size ranging between 20.2-36.4% and particle sizes 1-200 {mu}m. Many important phenomena including flow asymmetry, recirculating flow and particle dispersion in the combustion chamber have been predicted. The current model can reproduce the experimental observations including the effects on burnout of coal flowrate and the introduction of methane for lance cooling.

  7. Utilization of coal ash/coal combustion products for mine reclamation

    International Nuclear Information System (INIS)

    Dolence, R.C.; Giovannitti, E.

    1997-01-01

    Society's demand for an inexpensive fuel, combined with ignorance of the long term impacts, has left numerous scars on the Pennsylvania landscape. There are over 250,000 acres of abandoned surface mines with dangerous highwalls and water filled pits. About 2,400 miles of streams do not meet water quality standards because of drainage from abandoned mines. There are uncounted households without an adequate water supply due to past mining practices. Mine fires and mine subsidence plague many Pennsylvania communities. The estimated cost to reclaim these past scars is over $15 billion. The beneficial use of coal ash in Pennsylvania for mine reclamation and mine drainage pollution abatement projects increased during the past ten years. The increase is primarily due to procedural and regulatory changes by the Department of Environmental Protection (DEP). Prior to 1986, DEP required a mining permit and a separate waste disposal permit for the use of coal ash in backfilling and reclaiming a surface mine site. In order to eliminate the dual permitting requirements and promote mine reclamation, procedural changes now allow a single permit which authorize both mining and the use of coal ash in reclaiming active and abandoned pits. The actual ash placement, however, must be conducted in accordance with the technical specifications in the solid waste regulations

  8. Effect of resinite on the combustion of New Zealand subbituminous coal

    Energy Technology Data Exchange (ETDEWEB)

    Benfell, K.E.; Beamish, B.B.; Rodgers, K.A. [University of Newcastle, Callaghan, NSW (Australia). Dept. of Geology

    1997-09-01

    This paper shows that Oligocene resin from New Zealand`s Rotowaro coalfield displays DTA and DTG traces similar to those of other fossil resins. It modifies the thermal behaviour of low rank coal raising the peak combustion temperature and lowering its rate of combustion; this behaviour may be common among liptinite macerals. The effect is not additive and unlike other coal constituents the resinite component does not deteriorate with time.

  9. Inhibition Effect of Phosphorus Flame Retardants on the Fire Disasters Induced by Spontaneous Combustion of Coal

    Directory of Open Access Journals (Sweden)

    Yibo Tang

    2017-01-01

    Full Text Available Coal spontaneous combustion (CSC generally induces fire disasters in underground mines, thus causing serious casualties, environmental pollution, and property loss around the world. By using six P-containing additives to process three typical coal samples, this study investigated the variations of the self-ignition characteristics of the coal samples before and after treatment. The analysis was performed by combining thermogravimetric analysis/differential scanning calorimetry (TG/DSC Fourier transform infrared spectrometer (FTIR and low temperature oxidation. Experimental results showed that P-containing inhibitors could effectively restrain the heat emitted in the combustion of coal samples and therefore the ignition temperature of the coal samples was delayed at varying degrees. The combustion rate of the coal samples was reduced as well. At the temperatures ranging from 50°C to 150°C, the activation energy of the coal samples after the treatment was found to increase, which indicated that the coal samples were more difficult to be oxidized. After being treated with phosphorus flame retardants (PFRs, the content of several active groups represented by the C-O structure in the three coal samples was proved to be obviously changed. This suggested that PFRs could significantly inhibit the content of CO generated by the low temperature oxidation of coal, and the flame-retardant efficiency grew with the increasing temperature. At 200°C, the maximal inhibition efficiency reached approximately 85%.

  10. 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

  11. Predictions of the impurities in the CO2 stream of an oxy-coal combustion plant

    International Nuclear Information System (INIS)

    Liu, Hao; Shao, Yingjuan

    2010-01-01

    Whilst all three main carbon capture technologies (post-combustion, pre-combustion and oxy-fuel combustion) can produce a CO 2 dominant stream, other impurities are expected to be present in the CO 2 stream. The impurities in the CO 2 stream can adversely affect other processes of the carbon capture and storage (CCS) chain including the purification, compression, transportation and storage of the CO 2 stream. Both the nature and the concentrations of potential impurities expected to be present in the CO 2 stream of a CCS-integrated power plant depend on not only the type of the power plant but also the carbon capture method used. The present paper focuses on the predictions of impurities expected to be present in the CO 2 stream of an oxy-coal combustion plant. The main gaseous impurities of the CO 2 stream of oxy-coal combustion are N 2 /Ar, O 2 and H 2 O. Even the air ingress to the boiler and its auxiliaries is small enough to be neglected, the N 2 /Ar concentration of the CO 2 stream can vary between ca. 1% and 6%, mainly depending on the O 2 purity of the air separation unit, and the O 2 concentration can vary between ca. 3% and 5%, mainly depending on the combustion stoichiometry of the boiler. The H 2 O concentration of the CO 2 stream can vary from ca. 10% to over 40%, mainly depending on the fuel moisture and the partitioning of recycling flue gas (RFG) between wet-RFG and dry-RFG. NO x and SO 2 are the two main polluting impurities of the CO 2 stream of an oxy-coal combustion plant and their concentrations are expected to be well above those found in the flue gas of an air-coal combustion plant. The concentration of NO x in the flue gas of an oxy-coal combustion plant can be up to ca. two times to that of an equivalent air-coal combustion plant. The amount of NO x emitted by the oxy-coal combustion plant, however, is expected to be much smaller than that of the air-coal combustion plant. The reductions of the recirculated NO x within the combustion

  12. Dynamic behavior of tobacco waste in the coal-fired fluidized-bed boiler

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Kai; Chang, Jian; Chen, Honggang; Yang, Yongping [North China Electric Power Univ., Beijing (China). National Eng Lab for Biomass Power Generation Equipment; Yu, Bangting [China Univ. of Petroleum, Beijing (China). State Key Lab. of Heavy Oil Processing

    2013-07-01

    Circulating fluidized bed (CFB) technology is an advanced method for utilizing coal and other solid fuels in an environmentally acceptable manner. During the processing procedure in the nicotiana tabacum plants, lots of tobacco stem wastes are produced, which are normally being dumped to the landfill field. If this kind of waste can be used as a part of the fuel to be added into the coal in a CFB combustor, it will reduce the use of coal and then cut the net carbon emissions. To understand the complicated fluid dynamics of nicotiana tabacum wastes in the coal-fired CFB boiler, the mixing and segregation behavior of tobacco stalk are preliminary measured in a cylindrical fluidized bed. Obvious segregation behavior is found due to distinct differences in density and shape between tobacco stem and coal, which results in poor fluidization quality and bad combustion efficiency. To overcome this disadvantage, a jet with high gas velocity is introduced through the air distributor and a detailed experimental study is conducted in a fluidized bed made up of stem-sand mixture with different solid components at various jet velocities, which greatly improve the mixing performance of stem in the fluidized bed. The above findings are helpful for the technological upgrading of small- or middle-sized CFB boiler with adding tobacco stem into coal.

  13. Environmental impact of coal utilization (from raw material to waste resources): Proceedings

    International Nuclear Information System (INIS)

    Sahu, K.C.

    1991-10-01

    The proceedings contains 27 papers presented at the conference on environmental impact of coal utilization from raw material to waste resources which was held at the Indian Institute of Technology, Bombay, during 14-15 January 1991. The conference was held as a follow-up of the research project to study the impact of coal utilization. The project was undertaken jointly by the Indian Institute of Technology, Bombay and the University of Western Ontario, Canada. The project was funded by the International Development Research Centre, Ottawa (Canada). The principle themes of the conference were : occurrence of trace elements in coal, fate of trace elements during combustion of coal, characterisation of fly ash and its properties and utilization, and environmental impact of ash disposal. (M.G.B.)

  14. Development and testing of synthetic riprap constructed from coal combustion products (CCPs).

    Science.gov (United States)

    2014-07-01

    Even with an increase in the amount of coal combustion products (CCPs) used in concrete con-struction, soil stabilization, and other : applications, the coal power industry must dispose of a sig-nificant amount of fly ash and bottom ash. One potentia...

  15. NEW SOLID FUELS FROM COAL AND BIOMASS WASTE; FINAL

    International Nuclear Information System (INIS)

    Hamid Farzan

    2001-01-01

    Under DOE sponsorship, McDermott Technology, Inc. (MTI), Babcock and Wilcox Company (B and W), and Minergy Corporation developed and evaluated a sludge derived fuel (SDF) made from sewage sludge. Our approach is to dry and agglomerate the sludge, combine it with a fluxing agent, if necessary, and co-fire the resulting fuel with coal in a cyclone boiler to recover the energy and to vitrify mineral matter into a non-leachable product. This product can then be used in the construction industry. A literature search showed that there is significant variability of the sludge fuel properties from a given wastewater plant (seasonal and/or day-to-day changes) or from different wastewater plants. A large sewage sludge sample (30 tons) from a municipal wastewater treatment facility was collected, dried, pelletized and successfully co-fired with coal in a cyclone-equipped pilot. Several sludge particle size distributions were tested. Finer sludge particle size distributions, similar to the standard B and W size distribution for sub-bituminous coal, showed the best combustion and slagging performance. Up to 74.6% and 78.9% sludge was successfully co-fired with pulverized coal and with natural gas, respectively. An economic evaluation on a 25-MW power plant showed the viability of co-firing the optimum SDF in a power generation application. The return on equity was 22 to 31%, adequate to attract investors and allow a full-scale project to proceed. Additional market research and engineering will be required to verify the economic assumptions. Areas to focus on are: plant detail design and detail capital cost estimates, market research into possible project locations, sludge availability at the proposed project locations, market research into electric energy sales and renewable energy sales opportunities at the proposed project location. As a result of this program, wastes that are currently not being used and considered an environmental problem will be processed into a renewable

  16. Pyritic waste from precombustion coal cleaning: Amelioration with oil shale retort waste and sewage sludge for growth of soya beans

    International Nuclear Information System (INIS)

    Lewis, B.G.; Gnanapragasam, N.; Stevens, M.L.

    1994-01-01

    Solid residue from fossil fuel mining and utilization generally present little hazard to human health. However, because of the high volumes generated, they do pose unique disposal problems in terms of land use and potential degradation of soil and water. In the specific case of wastes from precombustion coal cleaning, the materials include sulfur compounds that undergo oxidation when exposed to normal atmospheric conditions and microbial action and then produce sulfuric acid. The wastes also contain compounds of metals and nonmetals at concentrations many times those present in the original raw coal. Additionally, the residues often contain coal particles and fragments that combust spontaneously if left exposed to the air, thus contributing to the air pollution that the coal cleaning process was designed to prevent. Federal and state efforts in the United States to ameliorate the thousands of hectares covered with these wastes have focused on neutralizing the acidity with limestone and covering the material with soil. The latter procedure creates additional degraded areas, which were originally farmland or wildlife habitat. It would seem preferable to reclaim the coal refuse areas without earth moving. The authors describe here experiments with neutralization of coal waste acidity using an alkaline waste derived from the extraction of oil from oil shale to grow soya beans (Glycine max. [L]) on a mixture of wastes and sewage sludge. Yield of plant material and content of nutrients an potentially toxic elements in the vegetation and in the growth mixtures were determined; results were compared with those for plants grown on an agricultural soil, with particular focus on boron

  17. Analysis of oxy-fuel combustion power cycle utilizing a pressurized coal combustor

    OpenAIRE

    Gazzino, Marco; Hong, Jongsup; Chaudhry, Gunaranjan; Brisson II, John G; Field, Randall; Ghoniem, Ahmed F

    2009-01-01

    Growing concerns over greenhouse gas emissions have driven extensive research into new power generation cycles that enable carbon dioxide capture and sequestration. In this regard, oxy-fuel combustion is a promising new technology in which fuels are burned in an environment of oxygen and recycled combustion gases. In this paper, an oxy-fuel combustion power cycle that utilizes a pressurized coal combustor is analyzed. We show that this approach recovers more thermal energy from the flue gases...

  18. Good news to use from the environmental front: coal combustion products as an environmental success story

    Energy Technology Data Exchange (ETDEWEB)

    Ward, J.N. [ISG Resources, Inc., Salt Lake City, UT (United States)

    2002-07-01

    ISG Resources in the USA's largest manager and marketer of coal combustion products, involved also in developing new technologies and applications for treatment and use of fly ash, bottom ash, boiler slag and FGD by-products. The paper, outlined in a series of 14 overheads, describes the USA's successes and initiatives so far in coal combustion products utilization. Further opportunities for the coal industry were discussed. The industry is encouraged to become involved now in carbon trading mechanisms for fly ash utilization displacing cement production.

  19. Using X-ray methods to evaluate the combustion sulfur minerals and graphitic carbon in coals and ashes

    International Nuclear Information System (INIS)

    Wertz, D.L.; Collins, L.W.

    1988-01-01

    Coals are complex mixtures of vastly different materials whose combustion kinetics may well exhibit symbiotic effects. Although the sulfur oxide gases produced during the combustion of coals may have a variety of sources, they are frequently caused by the thermal degradation of inorganic minerals to produce ''acid rain''. Since many of the minerals involved either as reactants or products in coal combustion produce well defined x-ray power diffraction (XRPD) patterns, the fate of these minerals may be followed by measuring the XRPD patterns of combustion products. Coal 1368P, a coal with an unusually high pyrite (FeS/sub 2/) fraction, has been the subject materials in our investigations of the fate of the inorganic minerals during combustion. These studies include measuring the fate of pyrite and of graphitic carbon in coal 1368P under varying combustion conditions. The results discussed in this paper were obtained by standard XRPD methods

  20. Air toxic emissions from the combustion of coal: Identifying and quantifying hazardous air pollutants from US coals

    Energy Technology Data Exchange (ETDEWEB)

    Szpunar, C.B.

    1992-09-01

    This report addresses the key air toxic emissions likely to emanate from continued and expanded use of domestic coal. It identifies and quantifies those trace elements specified in the US 1990 Clean Air Act Amendments, by tabulating selected characterization data on various source coals by region, state, and rank. On the basis of measurements by various researchers, this report also identifies those organic compounds likely to be derived from the coal combustion process (although their formation is highly dependent on specific boiler configurations and operating conditions).

  1. Air toxic emissions from the combustion of coal: Identifying and quantifying hazardous air pollutants from US coals

    International Nuclear Information System (INIS)

    Szpunar, C.B.

    1992-09-01

    This report addresses the key air toxic emissions likely to emanate from continued and expanded use of domestic coal. It identifies and quantifies those trace elements specified in the US 1990 Clean Air Act Amendments, by tabulating selected characterization data on various source coals by region, state, and rank. On the basis of measurements by various researchers, this report also identifies those organic compounds likely to be derived from the coal combustion process (although their formation is highly dependent on specific boiler configurations and operating conditions)

  2. Assessment of the content of arsenic in solid by-products from coal combustion

    Directory of Open Access Journals (Sweden)

    Wierońska Faustyna

    2017-01-01

    Full Text Available The coal combustion processes constitute one of the major sources of heavy metals emission into the atmosphere. From the point of view of the reduction of the emission of heavy metals and the selection of the correct exhaust gas treatment system, it is important to monitor the amount of trace elements in the solid fuels and in the solid by-products from coal combustion. One of these highly toxic elements is arsenic. The average content of arsenic in Polish hard coals and lignites is 0 ÷ 40 mg/kg [1] and 5 ÷ 15 mg/kg [2], respectively. The world average content of arsenic in hard coals and lignites, is equal to 9.0 ± 0.8 and 7.4 ± 1.4 mg/kg [3], respectively. During coal combustion processes, a significant amount of arsenic enters the atmosphere through gases and fly ashes. The proportions in which those two forms of arsenic occur in exhaust gases depend on the conditions of combustion processes [4]. The aim of the research was to determine the content of arsenic in coal blends and by-products of their combustion (slag, fly ash, gypsum, filter cakes. The determination of the arsenic quantity was performed using the Atomic Absorption Spectrometry with the electrothermal atomization.

  3. Improved Economic Performance of Municipal Solid Waste Combustion Plants by Model Based Combustion Control

    NARCIS (Netherlands)

    Leskens, M.

    2013-01-01

    The combustion of municipal solid waste (MSW) is used for its inertisation, reduction of its volume and the conversion of its energy content into heat and/or electricity. Operation and control of modern large scale MSW combustion (MSWC) plants is determined by economic and environmental objectives

  4. Application of the coal-mining waste in building ceramics production

    Directory of Open Access Journals (Sweden)

    Vaysman Yakov Iosifovich

    Full Text Available In the process of construction ceramics production a substantial quantity of non-renewable natural resources - clays - are used. One of the ways of science development in building materials production is investigation of the possibility of regular materials production using technogenic waste. Application of coal-mining waste (technogenic raw material in charge composition for production of ceramic products provides rational use of fuel, contributes to implementation of resource saving technologies on construction materials production enterprises. Though science development on revealing new raw material sources should be conducted with account for safety, reliability, technical, ecological and economical sides of the problem, which is especially current. The article deals with the problem of coal-mining waste usage in building ceramics production instead of fresh primary component (clay, fluxes, thinning agents and combustible additives. The interdependence between the density and shrinkage of the ceramic products and the amount and quality of coal-mining waste in its composition was established. The optimal proportion of coal-mining waste and clay in building ceramics production was estimated.

  5. Acid digestion of combustible waste. Status report 2

    International Nuclear Information System (INIS)

    Allen, C.; Cowan, R.; Divine, J.

    1978-10-01

    The Radioactive Acid Digestion Test Unit (RADTU) has been constructed at Hanford to process combustible transuranic waste. Laboratory testing, pilot plant testing, engineering studies, and safety studies have been completed and incorporated in the system design. 44 figures, 7 tables

  6. Legislative and Regulatory Timeline for Fossil Fuel Combustion Wastes

    Science.gov (United States)

    This timeline walks through the history of fossil fuel combustion waste regulation since 1976 and includes information such as regulations, proposals, notices, amendments, reports and meetings and site visits conducted.

  7. The technology available for more efficient combustion of waste gases

    International Nuclear Information System (INIS)

    Burrows, J.

    1999-01-01

    Alternative combustion technologies for open flare systems are discussed, stressing their advantages and limitations while meeting the fundamental requirements of personnel and plant safety, high destruction efficiencies, environmental parameters and industrial reliability. The use of BACT (Best Available Control Technologies) is dependent on the destruction efficiency of waste gas defined by regulatory agencies or industrial leaders. Enclosed vapour combustors and high destruction efficiency thermal oxidation are two of the technologies which result in more efficient combustion of waste gases. There are several conditions that should be considered when choosing combustion equipment for the disposal of waste gas. These include volatile organic compounds content, lower heating value, the composition of the waste gas, the specified combustion efficiency, design flow rates, smokeless operation, operating conditions, ground level radiation, SO 2 dispersion, environmental and social expectations, and economic limitation. 10 figs

  8. Prevention of trace and major element leaching from coal combustion products by hydrothermally-treated coal ash

    Energy Technology Data Exchange (ETDEWEB)

    Adnadjevic, B.; Popovic, A.; Mikasinovic, B. [University of Belgrade, Belgrade (Serbia). Dept. of Chemistry

    2009-07-01

    The most important structural components of coal ash obtained by coal combustion in 'Nikola Tesla A' power plant located near Belgrade (Serbia) are amorphous alumosilicate, alpha-quartz, and mullite. The phase composition of coal ash can be altered to obtain zeolite type NaA that crystallizes in a narrow crystallization field (SiO{sub 2}/Al{sub 2}O{sub 3}; Na{sub 2}O/SiO{sub 2}; H{sub 2}O/Na{sub 2}O ratios). Basic properties (crystallization degree, chemical composition, the energy of activation) of obtained zeolites were established. Coal ash extracts treated with obtained ion-exchange material showed that zeolites obtained from coal ash were able to reduce the amounts of iron, chromium, nickel, zinc, copper, lead, and manganese in ash extracts, thus proving its potential in preventing pollution from dump effluent waters.

  9. ELECTROKINETIC DENSIFICATION OF COAL FINES IN WASTE PONDS

    Energy Technology Data Exchange (ETDEWEB)

    E. James Davis

    1999-12-18

    The objective of this research was to demonstrate that electrokinetics can be used to remove colloidal coal and mineral particles from coal-washing ponds and lakes without the addition of chemical additives such as salts and polymeric flocculants. The specific objectives were: Design and develop a scaleable electrophoresis apparatus to clarify suspensions of colloidal coal and clay particles; Demonstrate the separation process using polluted waste water from the coal-washing facilities at the coal-fired power plants in Centralia, WA; Develop a mathematical model of the process to predict the rate of clarification and the suspension electrical properties needed for scale up.

  10. Characteristics of fundamental combustion and NOx emission using various rank coals.

    Science.gov (United States)

    Kim, Sung Su; Kang, Youn Suk; Lee, Hyun Dong; Kim, Jae-Kwan; Hong, Sung Chang

    2011-03-01

    Eight types of coals of different rank were selected and their fundamental combustion characteristics were examined along with the conversion of volatile nitrogen (N) to nitrogen oxides (NOx)/fuel N to NOx. The activation energy, onset temperature, and burnout temperature were obtained from the differential thermogravimetry curve and Arrhenius plot, which were derived through thermo-gravimetric analysis. In addition, to derive the combustion of volatile N to NOx/fuel N to NOx, the coal sample, which was pretreated at various temperatures, was burned, and the results were compared with previously derived fundamental combustion characteristics. The authors' experimental results confirmed that coal rank was highly correlated with the combustion of volatile N to NOx/fuel N to NOx.

  11. Zinc isotopic composition of particulate matter generated during the combustion of coal and coal + tire-derived fuels

    Science.gov (United States)

    Borrok, D.M.; Gieré, R.; Ren, M.; Landa, E.R.

    2010-01-01

    Atmospheric Zn emissions from the burning of coal and tire-derived fuel (TDF) for power generation can be considerable. In an effort to lay the foundation for tracking these contributions, we evaluated the Zn isotopes of coal, a mixture of 95 wt % coal + 5 wt % TDF, and the particulate matter (PM) derived from their combustion in a power-generating plant. The average Zn concentrations and δ(66)Zn were 36 mg/kg and 183 mg/kg and +0.24‰ and +0.13‰ for the coal and coal + TDF, respectively. The δ(66)Zn of the PM sequestered in the cyclone-type mechanical separator was the lightest measured, -0.48‰ for coal and -0.81‰ for coal+TDF. The δ(66)Zn of the PM from the electrostatic precipitator showed a slight enrichment in the heavier Zn isotopes relative to the starting material. PM collected from the stack had the heaviest δ(66)Zn in the system, +0.63‰ and +0.50‰ for the coal and coal + TDF, respectively. Initial fractionation during the generation of a Zn-rich vapor is followed by temperature-dependent fractionation as Zn condenses onto the PM. The isotopic changes of the two fuel types are similar, suggesting that their inherent chemical differences have only a secondary impact on the isotopic fractionation process.

  12. Thermal alterations of organic matter in coal wastes from Upper Silesia, Poland

    Science.gov (United States)

    Misz-Kennan, Magdalena

    2010-01-01

    Self-heating and self-combustion are currently taking place in some coal waste dumps in the Upper Silesian Coal Basin, Poland, e.g. the dumps at Rymer Cones, Starzykowiec, and the Marcel Coal Mine, all in the Rybnik area. These dumps are of similar age and self-heating and combustion have been occurring in all three for many years. The tools of organic petrography (maceral composition, rank, etc.), gas chromatography-mass spectrometry, and proximate and ultimate analysis are used to investigate the wastes. Organic matter occurs in quantities up to 85 vol.%, typically a few to several vol.%, in the wastes. All three maceral groups (vitrinite, liptinite, and inertinite) are present as unaltered and variously-altered constituents associated with newly-formed petrographic components (bitumen expulsions, pyrolytic carbon). The predominant maceral group is vitrinite with alterations reflected in the presence of irregular cracks, oxidation rims and, rarely, devolatilisation pores. In altered wastes, paler grey-vitrinite and/or coke dominates. The lack of plasticity, the presence of paler-coloured particles, isotropic massive coke, dispersed coked organic matter, and expulsions of bitumens all indicate that heating was slow and extended over a long time. Macerals belonging to other groups are present in unaltered form or with colours paler than the colours of the parent macerals. Based on the relative contents of organic compounds, the most important groups of these identified in the wastes are n-alkanes, acyclic isoprenoids, hopanes, polycyclic aromatic hydrocarbons (PAHs) and their derivatives, phenol and its derivatives. These compounds occur in all wastes except those most highly altered where they were probably destroyed by high temperatures. These compounds were generated mainly from liptinite-group macerals. Driven by evaporation and leaching, they migrated within and out of the dump. Their presence in some wastes in which microscopically visible organic matter is

  13. Characterizing the Leaching Behavior of Coal Combustion Residues using the Leaching Environmental Assessment Framework (LEAF) to Inform Future Management Decisions

    Science.gov (United States)

    Abstract for presentation on Characterizing the Leaching Behavior of Coal Combustion Residues using the Leaching Environmental Assessment Framework (LEAF) to Inform Future Management Decisions. The abstract is attached.

  14. Thermal effects from the release of selenium from a coal combustion during high-temperature processing: a review.

    Science.gov (United States)

    Hu, Jianjun; Sun, Qiang; He, Huan

    2018-04-11

    The release of selenium (Se) during coal combustion can have serious impacts on the ecological environment and human health. Therefore, it is very important to study the factors that concern the release of Se from coal combustion. In this paper, the characteristics of the release of Se from coal combustion, pyrolysis, and gasification of different coal species under different conditions are studied. The results show that the amount of released Se increases at higher combustion temperatures. There are obvious increases in the amount of released Se especially in the temperature range of 300 to 800 °C. In addition, more Se is released from the coal gasification than coal combustion process, but more Se is released from coal combustion than pyrolysis. The type of coal, rate of heating, type of mineral ions, and combustion atmosphere have different effects on the released percentage of Se. Therefore, having a good understanding of the factors that surround the release of Se during coal combustion, and then establishing the combustion conditions can reduce the impacts of this toxic element to humans and the environment.

  15. Production of Indigenous and Enriched Khyber Pakhtunkhwa Coal Briquettes: Combustion and Disintegration Strength Analysis

    International Nuclear Information System (INIS)

    Habib, M.; Khan, A.U.; Habib, U.; Memon, A.R.

    2013-01-01

    Khyber Pakhtun Khwa province of Pakistan has considerable amounts of low ranked coal. However, due to the absence of any centrally administered power generation system there is a need to explore indigenous methods for effectively using this valuable energy resource. In the present study an indigenous coal briquetting technology has been developed and evaluated in terms of combustion characteristics such as moisture content, volatile matter, ash, fixed carbon and calorific value of the resulting coal briquette and disintegration strength using polyvinyl acetate (PVA) in combination with calcium carbonate (sample no 3 with highest disintegration strength value of 2059N). Comparison of test samples with the commercially available coal briquettes revealed improved combustion characteristics for the PVA bonded (sample no 1 and 5) coal briquettes having higher fixed carbon content and calorific value, lower ash contents as well as lower initial ignition time. (author)

  16. Production of Indigenous and Enriched Khyber Pakhtunkhwa Coal Briquettes: Combustion and Disintegration Strength Analysis

    Directory of Open Access Journals (Sweden)

    Unsia Habib

    2013-06-01

    Full Text Available Khyber Pakhtun Khwa province of Pakistan has considerable amounts of low ranked coal. However, due to the absence of any centrally administered power generation system there is a need to explore indigenous methods for effectively using this valuable energy resource. In the present study an indigenous coal briquetting technology has been developed and evaluated in terms of combustion characteristics such as moisture content, volatile matter, ash, fixed carbon and calorific value of the resulting coal briquette and disintegration strength using polyvinyl acetate (PVA in combination with calcium carbonate (sample no 3 with highest disintegration strength value of 2059N. Comparison of test samples with the commercially available coal briquettes revealed improved combustion characteristics for the PVA bonded (sample no 1 and 5 coal briquettes having higher fixed carbon content and calorific value, lower ash contents as well as lower initial ignition time.

  17. Boron availability to plants from coal combustion by-products

    International Nuclear Information System (INIS)

    Kukier, U.; Sumner, M.E.

    1996-01-01

    Agronomic use of coal combustion by-products is often associated with boron (B) excess in amended soils and subsequently in plants. A greenhouse study with corn (Zea mays L.) as test plant was conducted to determine safe application rates of five fly ashes and one flue gas desulfurization gypsum (FDG). All by-products increased soil and corn tissue B concentration, in some cases above toxicity levels which are 5 mg hot water soluble B (hwsB)kg -1 soil and 100 mg B kg -1 in corn tissue. Acceptable application rates varied from 4 to 100 Mg ha -1 for different by-products. Leaching and weathering of a high B fly ash under ponding conditions decreased its B content and that of corn grown in fly ash amended soil, while leaching of the same fly ash under laboratory conditions increased fly ash B availability to corn in comparison to the fresh fly ash. Hot water soluble B in fly ash or FDG amended soil correlated very well with corn tissue B. Hot water soluble B in fly ash amended soil could be predicted based on soil pH and B solubility in ash at different pH values but not so in the case of FDG. Another greenhouse study was conducted to compare the influence of FDG and Ca(OH 2 ) on B concentration in spinach (Spinacia oleracea L.) leaves grown in soil amended with the high B fly ash. The Ca(OH) 2 significantly decreased tissue B content, while FDG did not affect B uptake from fly ash amended soil. 41 refs., 6 figs., 5 tabs

  18. Problem of formation of nitrogen oxides during coal combustion in power plant steam generators

    Energy Technology Data Exchange (ETDEWEB)

    Kotler, V.R.; Kuvaev, Yu.V.

    1992-07-01

    Analyzes a study of physical and chemical processes of nitrogen oxide formation during coal combustion conducted at Stanford University (USA). Experimental installation, pulverized coal feeding as well as measuring techniques and equipment are described. Experiments were conducted with 55 micron particles of semibituminous coal. An equation for the percentage of coal carbon converted to gaseous products is given. Active formation of NO from nitrogen content in the fuel was observed when oxygen content was under 4%. Conversion of the fuel nitrogen to NO[sub x] in the 1,350-1,850 K temperature range did not depend on gas temperature but rather on oxygen content. 2 refs.

  19. Oxy-coal combustion in an entrained flow reactor: Application of specific char and volatile combustion and radiation models for oxy-firing conditions

    DEFF Research Database (Denmark)

    Álvarez, L.; Yin, Chungen; Riaza, J.

    2013-01-01

    The deployment of oxy-fuel combustion in utility boilers is one of the major options for CO2 capture. However, combustion under oxy-firing conditions differs from conventional air-firing combustion, e.g., in the aspect of radiative heat transfer, coal conversion and pollutants formation....... In this work, a numerical study on pulverised coal combustion was conducted to verify the applicability and accuracy of several sub-models refined for oxy-fuel conditions, e.g., gaseous radiative property model, gas-phase combustion mechanism and heterogeneous char reaction model. The sub-models were...... implemented in CFD (Computational Fluid Dynamics) simulations of combustion of three coals under air-firing and various oxy-firing (21-35% vol O2 in O2/CO2 mixture) conditions in an EFR (entrained flow reactor). The predicted coal burnouts and gaseous emissions were compared against experimental results...

  20. Reduction of NOx and particulate emissions from coal-fired boilers by modification of coal nozzles and combustion tuning

    Energy Technology Data Exchange (ETDEWEB)

    Chudnovsky, B.; Talanker, A.; Mugenstein, A.; Shpon, G.; Vikhansky, A.; Elperin, T.; Bar-Ziv, E.; Bockelie, M.; Eddings, E.; Sarofim, A.F. [Israel Electric Corporation, Haifa (Israel). Engineering Division

    2001-07-01

    In the present paper two issues are discussed: the effect of the burner replacement on boiler performance and NOx emissions and the effect of the burner replacement on performance and efficiency of electrostatic precipitators (ESP). We also have experimented with different coal types and found the coals that together with combustion tuning met commonly accepted emission limits for NOx (less than 600 mg/dNm{sup 3}) and levels of carbon in fly ash (LOI) (approximately 5-6%) for existing boilers without low NOx burners. Our measurements were accompanied by computer simulations of the combustion of the combustion process in the boiler. Special attention was paid to detailed simulation of the flow and ignition in the near-burner zone. 7 refs., 12 figs., 5 tabs.

  1. Burnout synergic or inhibiting effects in combustion assays of coal/sawdust blends

    Energy Technology Data Exchange (ETDEWEB)

    Ximena Garcia; Ximena Matus; Claudia Ulloa; Alfredo L. Gordon [University of Concepcion, Concepcion (Chile). Dept. of Chemical Engineering

    2007-07-01

    Characterization of chars and charcoal and combustion assays of coal/ pine sawdust blends were carried on to evaluate the burnout, under conditions similar to those found in pulverized coal combustion. A drop tube furnace (DTF) was used to generate chars from three coals of different rank (Bitsch, a lignite; Lemington, a bituminous HV coal; and LD, a semianthracite) and charcoal from sawdust (S). Burning profiles, as well as morphological and optical characterization of these chars were obtained and discussed. Pulverized samples of pure constituents and sawdust/coal blends (5, 10 and 20%wt of S) were burned in the DTF reactor. Samples of combustion residues were collected for characterization. Depending on blend composition and the rank of the coal being blended, positive and negative deviations with respect to the expected weighted average value of the burnout were measured. This behavior is related both, to the duration of the step by which simultaneous burning of char and charcoal take place, and to the sawdust content in the blend. The optical analysis of combustion residues supports this conclusion. 7 refs., 6 figs., 3 tabs.

  2. Removal of mercury from coal-combustion flue gas using regenerable sorbents

    Energy Technology Data Exchange (ETDEWEB)

    Turchi, C S; Albiston, J; Broderick, T E; Stewart, R M

    1999-07-01

    The US EPA estimates that coal-fired power plants constitute the largest anthropogenic source of mercury emissions in the US. The Agency has contemplated emission regulations for power plants, but the large gas-flow rates and low mercury concentrations involved have made current treatment options prohibitively expensive. ADA Technologies, Inc. (Englewood, Colorado), in conjunction with the US DOE, is developing regenerable sorbents for the removal and recovery of mercury from flue gas. These sorbents are based on the ability of noble metals to amalgamate mercury at typical flue-gas temperatures and release mercury at higher temperatures. The process allows for recovery of mercury with minimal volumes of secondary wastes and no impact on fly ash quality. In 1997 and 1998, ADA tested a 20-cfm sorbent unit at CONSOL Inc.'s coal-combustion test facility in Library, PA. Results from the 1997 tests indicated that the sorbent can remove elemental and oxidized mercury and can be regenerated without loss of capacity. Design changes were implemented in 1998 to enhance the thermal efficiency of the process and to recover the mercury in a stable form. Testing during autumn, 1998 demonstrated 60% to 90% removal efficiency of mercury from a variety of different coals. However, contradictory removal results were obtained at the end of the test period. Subsequent laboratory analyses indicated that the sorbent had lost over half its capacity for mercury due to a decrease in available sites for mercury sorption. The presence of sulfur compounds on the sorbent suggests that thermal cycling may have condensed acid gases on the sorbent leading to deterioration of the active sorption sites. The regeneration time/temperature profile has been altered to minimize this potential in the upcoming power plant tests.

  3. Tracing the combustion of coal blends in a thermobalance by optical microscopy

    Energy Technology Data Exchange (ETDEWEB)

    E. Osorio; M.L.F. Ghiggi; A.C.F. Vilela; W.D. Kalkreuth; D. Alvarez; A.G. Borrego [Universidade Federal do Rio Grande do Sul, Porto Alegre (Brazil). Laboratorio de Siderurgia

    2007-07-01

    Combustion at programmed temperature in a thermobalance is a common test for the rapid assessment of coal combustibility. In this study two series of blends (low rank/medium rank coal-AB and low rank /petroleum coke-AC) with the low rank coal in three different proportions (1/4, 2/4 and 3/4) have been tested. Samples have been ground and sieved to 20-75 m prior to blend preparation. The combustion profiles indicated different behaviour for the two series of samples: the AB series showed wide curves with the presence of shoulders whereas the AC series showed two maxima corresponding to the component fuels. The comparison of the calculated and experimental curves indicated different effects of blending on the relevant temperatures and reactivity of the blends. In the AB blend both initial and peak temperatures were lower than expected and the higher the proportion of low rank coal, the larger the difference. In the AC series the burnout temperature was the parameter departing more from the expected values. In order to visualize relative combustibility of the coals the reaction was stopped at 50% conversion and the samples were examined through the microscope. The combustion of the particles followed a shrinking core pattern in which the core of the low rank particles remained isotropic whereas anisotropy development was observed in the medium rank coal. The reflectance of the coals increased with increasing the temperature at which the reaction was stopped regardless the rank of the parent coal following a linear trend. 5 refs., 5 figs., 1 tab.

  4. Combustion characteristics of Malaysian oil palm biomass, sub-bituminous coal and their respective blends via thermogravimetric analysis (TGA).

    Science.gov (United States)

    Idris, Siti Shawalliah; Rahman, Norazah Abd; Ismail, Khudzir

    2012-11-01

    The combustion characteristics of Malaysia oil palm biomass (palm kernel shell (PKS), palm mesocarp fibre (PMF) and empty fruit bunches (EFB)), sub-bituminous coal (Mukah Balingian) and coal/biomass blends via thermogravimetric analysis (TGA) were investigated. Six weight ratios of coal/biomass blends were prepared and oxidised under dynamic conditions from temperature 25 to 1100°C at four heating rates. The thermogravimetric analysis demonstrated that the EFB and PKS evolved additional peak besides drying, devolatilisation and char oxidation steps during combustion. Ignition and burn out temperatures of blends were improved in comparison to coal. No interactions were observed between the coal and biomass during combustion. The apparent activation energy during this process was evaluated using iso-conversional model free kinetics which resulted in highest activation energy during combustion of PKS followed by PMF, EFB and MB coal. Blending oil palm biomass with coal reduces the apparent activation energy value. Copyright © 2012 Elsevier Ltd. All rights reserved.

  5. Petrographic and mineral characterization of Balkan coals and their solid waste products from coal preparation

    International Nuclear Information System (INIS)

    Yossifova, M.

    1995-01-01

    This paper is part of a complex petrographic, mineralogical and chemical investigation on Balkan bituminous coals and their solid waste products from coal preparation. The petrographic and phase-mineralogical composition in ten composite samples and four water extracts have been studied by optical microscopy, scanning electron microscopy and X-ray diffraction. 4 refs., 4 tabs

  6. 40 CFR 60.1015 - What is a new municipal waste combustion unit?

    Science.gov (United States)

    2010-07-01

    ... combustion unit? 60.1015 Section 60.1015 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED... for Small Municipal Waste Combustion Units for Which Construction is Commenced After August 30, 1999... What is a new municipal waste combustion unit? (a) A new municipal waste combustion unit is a municipal...

  7. Coal combustion by-product (CCB) utilization in turfgrass sod production

    Energy Technology Data Exchange (ETDEWEB)

    Schlossberg, M.J.; Miller, W.P. [University of Georgia, Athens, GA (United States). Dept. of Crop & Soil Science

    2004-04-01

    Coal combustion by-products (CCB) are produced nationwide, generating 101 Mg of waste annually. Though varied, the majority of CCB are crystalline alumino-silicate minerals. Both disposal costs of CCB and interest in alternative horticultural/agricultural production systems have increased recently. Field studies assessed the benefit of CCB and organic waste/product mixtures as supplemental soil/growth media for production of hybrid bermudagrass (Cynodon dactylon (L.) Pers. x C. transvaalensis Burtt-Davy) sod. Growth media were applied at depths of 2 to 4 cm (200 to 400 m{sup 3}{center_dot}ha{sup -1}) and vegetatively established by sprigging. Cultural practices typical of commercial methods were employed over 99- or 114-day growth periods. Sod was monitored during these propagation cycles, then harvested, evaluated, and installed offsite in a typical lawn-establishment method. Results showed mixtures of CCB and biosolids as growth media increased yield of biomass, with both media and tissue having greater nutrient content than the control media. Volumetric water content of CCB-containing media significantly exceeded that of control media and soil included with a purchased bermudagrass sod. Once installed, sod grown on CCB-media did not differ in rooting strength from control or purchased sod. When applied as described, physicochemical characteristics of CCB-media are favorable and pose little environmental risk to soil or water resources.

  8. A Model for Nitrogen Chemistry in Oxy-Fuel Combustion of Pulverized Coal

    DEFF Research Database (Denmark)

    Hashemi, Hamid; Hansen, Stine; Toftegaard, Maja Bøg

    2011-01-01

    , heating and devolatilization of particles, and gas–solid reactions. The model is validated by comparison with entrained flow reactor results from the present work and from the literature on pulverized coal combustion in O2/CO2 and air, covering the effects of fuel, mixing conditions, temperature......In this work, a model for the nitrogen chemistry in the oxy-fuel combustion of pulverized coal has been developed. The model is a chemical reaction engineering type of model with a detailed reaction mechanism for the gas-phase chemistry, together with a simplified description of the mixing of flows......, stoichiometry, and inlet NO level. In general, the model provides a satisfactory description of NO formation in air and oxy-fuel combustion of coal, but under some conditions, it underestimates the impact on NO of replacing N2 with CO2. According to the model, differences in the NO yield between the oxy...

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

    International Nuclear Information System (INIS)

    Christofiedes, N.; Brown, R.C.

    1992-01-01

    In this paper, the authors investigate a method for simultaneous determination of devolatilization and char burnout times based on the analysis of CO 2 emissions from a fluidized bed combustor. The technique is non-intrusive and can be performed under realistic combustion conditions. The authors' method involves batching single-size coal samples in a fluidized bed combustor that is heated with propane gas or other fuel. Carbon dioxide profiles versus time for the batch tests are analyzed with a linear model to obtain characteristic time constants for coal devolatilization and char combustion which can be related to total devolatilization time and burnout time for a coal sample. The authors' approach does not require special sample preparation, can be performed in actual combustion equipment and employs standard boiler instrumentation

  10. Low-rank coal research

    Energy Technology Data Exchange (ETDEWEB)

    Weber, G. F.; Laudal, D. L.

    1989-01-01

    This work is a compilation of reports on ongoing research at the University of North Dakota. Topics include: Control Technology and Coal Preparation Research (SO{sub x}/NO{sub x} control, waste management), Advanced Research and Technology Development (turbine combustion phenomena, combustion inorganic transformation, coal/char reactivity, liquefaction reactivity of low-rank coals, gasification ash and slag characterization, fine particulate emissions), Combustion Research (fluidized bed combustion, beneficiation of low-rank coals, combustion characterization of low-rank coal fuels, diesel utilization of low-rank coals), Liquefaction Research (low-rank coal direct liquefaction), and Gasification Research (hydrogen production from low-rank coals, advanced wastewater treatment, mild gasification, color and residual COD removal from Synfuel wastewaters, Great Plains Gasification Plant, gasifier optimization).

  11. Mercury speciation and fine particle size distribution on combustion of Chinese coals

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Lei; Wang, Shuxiao; Hao, Jiming [Tsinghua Univ., Beijing (China). Dept. of Environmental Science and Engineering and State Key Joint Lab. of Environment Simulation and Pollution Control; Daukoru, Michael; Torkamani, Sarah; Biswas, Pratim [Washington Univ., St. Louis, MO (United States). Aerosol and Air Quality Research Lab.

    2013-07-01

    Coal combustion is the dominant anthropogenic mercury emission source of the world. Electrostatic precipitator (ESP) can remove almost all the particulate mercury (Hg{sub p}), and wet flue gas desulfurization (WFGD) can retain a large part of the gaseous oxidized mercury (Hg{sup 2+}). Only a small percentage of gaseous elemental mercury (Hg{sup 0}) can be abated by the air pollution control devices (APCDs). Therefore, the mercury behavior across APCDs largely depends on the mercury speciation in the flue gas exhausting from the coal combustor. To better understand the formation process of three mercury species, i.e. Hg{sup 0}, Hg{sup 2+} and Hg{sub p}, in gaseous phase and fine particles, bench-scale measurements for the flue gas exhausting from combustion of different types of coal in a drop-tube furnace set-up, were carried out. It was observed that with the limitation of reaction kinetics, higher mercury concentration in flue gas will lead to lower Hg{sup 2+} proportion. The concentration of chlorine has the opposite effect, not as significantly as that of mercury though. With the chlorine concentration increasing, the proportion of Hg{sup 2+} increases. Combusting the finer coal powder results in the formation of more Hg{sup 2+}. Mineral composition of coal and coal particle size has a great impact on fine particle formation. Al in coal is in favor of finer particle formation, while Fe in coal can benefit the formation of larger particles. The coexistence of Al and Si can strengthen the particle coagulation process. This process can also be improved by the feeding of more or finer coal powder. The oxy-coal condition can make for both the mercury oxidation process and the metal oxidation in the fine particle formation process.

  12. Multifaceted processes controlling the distribution of hazardous compounds in the spontaneous combustion of coal and the effect of these compounds on human health.

    Science.gov (United States)

    Oliveira, Marcos L S; da Boit, Kátia; Pacheco, Fernanda; Teixeira, Elba C; Schneider, Ismael L; Crissien, Tito J; Pinto, Diana C; Oyaga, Rafael M; Silva, Luis F O

    2018-01-01

    Pollution generated by hazardous elements and persistent organic compounds that affect coal fire is a major environmental concern because of its toxic nature, persistence, and potential risk to human health. The coal mining activities are growing in the state of Santa Catarina in Brazil, thus the collateral impacts on the health and economy are yet to be analyzed. In addition, the environment is also enduring the collateral damage as the waste materials directly influence the coal by-products applied in civil constructions. This study was aimed to establish the relationships between the composition, morphology, and structural characteristics of ultrafine particles emitted by coal mine fires. In Brazil, the self-combustions produced by Al-Ca-Fe-Mg-Si coal spheres are rich in chalcophile elements (As, Cd, Cu, Hg, Pb, Sb, Se, Sn, and Zn), lithophile elements (Ce, Hf, In, La, Th, and U), and siderophile elements (Co, Cr, Mo, Fe, Ni, and V). The relationship between nanomineralogy and the production of hazardous elements as analyzed by advanced methods for the geochemical analysis of different materials were also delineated. The information obtained by the mineral substance analysis may provide a better idea for the understanding of coal-fire development and assessing the response of particular coal in different combustion processes. Copyright © 2017 Elsevier Inc. All rights reserved.

  13. Ecofriendly bricks elaborated from coal waste of Moroccan Jerrada Mining

    Directory of Open Access Journals (Sweden)

    Ez-zaki H.

    2018-01-01

    Full Text Available Solid waste generated during mining is one of the major environmental problems associated with this industrial activity. The best solution to overcome the environmental impact of this waste is to find recycling facilities in mass-produced products that can absorb the large quantities of these available byproducts. The present study shows the feasibility of using the coal waste of Moroccan Jerrada mining in the production of ecological brick. The first step consists of consecutive stages of crushing, grinding and heating at 650°C of the coal waste with a small amount of lime in order to promote the reactive products of elaborated binders. The second step of the process consists of mixing treated coal waste with a small amount of marble dust, sand, gravel, and water, then pressed and dried at room temperature to manufacture a laboratory ecofriendly bricks. The mechanical strength and thermal conductivity are investigated.

  14. Coal Combustion Behavior in New Ironmaking Process of Top Gas Recycling Oxygen Blast Furnace

    Science.gov (United States)

    Zhou, Zhenfeng; Xue, Qingguo; Tang, Huiqing; Wang, Guang; Wang, Jingsong

    2017-10-01

    The top gas recycling oxygen blast furnace (TGR-OBF) is a new ironmaking process which can significantly reduce the coke ratio and emissions of carbon dioxide. To better understand the coal combustion characteristics in the TGR-OBF, a three dimensional model was developed to simulate the lance-blowpipe-tuyere-raceway of a TGR-OBF. The combustion characteristics of pulverized coal in TGR-OBF were investigated. Furthermore, the effects of oxygen concentration and temperature were also analyzed. The simulation results show that the coal burnout increased by 16.23% compared to that of the TBF. The oxygen content has an obvious effect on the burnout. At 70% oxygen content, the coal burnout is only 21.64%, with a decrease of 50.14% compared to that of TBF. Moreover, the effect of oxygen temperature is also very obvious.

  15. [Inventories of atmospheric arsenic emissions from coal combustion in China, 2005].

    Science.gov (United States)

    Tian, He-Zhong; Qu, Yi-Ping

    2009-04-15

    Anthropogenic arsenic (As) emitted from coal combustion is one of key trace elements leading to negative air pollution and national economy loss. It is of great significance to estimate the atmospheric arsenic emission for proposing relevant laws or regulations and selecting proper pollution control technologies. The inventories of atmospheric arsenic emissions from coal combustion in China were evaluated by adopting the emission factor method based on fuel consumption. Arsenic emission sources were firstly classified into several categories by economic sectors, combustion types and pollution control technologies. Then, according to provincial coal consumption and averaged arsenic concentration in the feed fuel, the inventories of atmospheric arsenic emission from coal combustion in China in 2005 were established. Coal outputand consumption in China in 2005 were 2,119.8 and 2,099.8 Mt, respectively. The total emissions of arsenic released into the atmosphere in 2005 in China were estimated at about 1,564.4 t, and Shandong ranked the largest province with 144.4 t arsenic release, followed by Hunan (141.1 t), Hebei (108.5 t), Henan (77.7 t), and Jiangsu (77.0 t), which were mainly concentrated in the eastern and central provinces of China. The arsenic emissions were largely emitted by industry sector (818.8 t) and thermal power generation sector (303.4 t), contributing 52.3% and 19.4% of the totals, respectively. About 375.5 t arsenic was estimated to be released into the atmosphere in the form of gas phase in China in 2005, with a share of 24% of the totals. In general, arsenic pollution control from coal combustion should be highlighted for the power and industry sectors in the whole country. However, arsenic poisoning caused by residential coal burning should also be paid great attention in some areas such as Xinjiang, Gansu, Qinghai and Guishou.

  16. Modeling coal combustion behavior in an ironmaking blast furnace raceway: model development and applications

    Energy Technology Data Exchange (ETDEWEB)

    Maldonado, D.; Austin, P.R.; Zulli, P.; Guo B. [BlueScope Steel Research Laboratories, Port Kembla, NSW (Australia)

    2009-03-15

    A numerical model has been developed and validated for the investigation of coal combustion phenomena under blast furnace operating conditions. The model is fully three-dimensional, with a broad capacity to analyze significant operational and equipment design changes. The model was used in a number of studies, including: Effect of cooling gas type in coaxial lance arrangements. It was found that oxygen cooling improves coal burnout by 7% compared with natural gas cooling under conditions that have the same amount of oxygen enrichment in the hot blast. Effect of coal particle size distribution. It was found that during two similar periods of operation at Port Kembla's BF6, a difference in PCI capability could be attributed to the difference in coal size distribution. Effect of longer tuyeres. Longer tuyeres were installed at Port Kembla's BF5, leading to its reline scheduled for March 2009. The model predicted an increase in blast velocity at the tuyere nose due to the combustion of volatiles within the tuyere, with implications for tuyere pressure drop and PCI capability. Effect of lance tip geometry. A number of alternate designs were studied, with the best-performing designs promoting the dispersion of the coal particles. It was also found that the base case design promoted size segregation of the coal particles, forcing smaller coal particles to one side of the plume, leaving larger coal particles on the other side. 11 refs., 15 figs., 4 tabs.

  17. Evaluation of AFBC co-firing of coal and hospital wastes

    Energy Technology Data Exchange (ETDEWEB)

    1991-02-01

    The purpose of this program is to expand the use of coal by utilizing CFB (circulating fluidized bed) technology to provide an environmentally safe method for disposing of waste materials. Hospitals are currently experiencing a waste management crisis. In many instances, they are no longer permitted to burn pathological and infectious wastes in incinerators. Older hospital incinerators are not capable of maintaining the stable temperatures and residence times necessary in order to completely destroy toxic substances before release into the atmosphere. In addition, the number of available landfills which can safely handle these substances is decreasing each year. The purpose of this project is to conduct necessary research investigating whether the combustion of the hospital wastes in a coal-fired circulating fluidized bed boiler will effectively destroy dioxins and other hazardous substances before release into the atmosphere. If this is proven feasible, in light of the quantity of hospital wastes generated each year, it would create a new market for coal -- possibly 50 million tons/year.

  18. Preparation and evaluation of coal-derived activated carbons for removal of mercury vapor from simulated coal combustion flue fases

    Science.gov (United States)

    Hsi, H.-C.; Chen, S.; Rostam-Abadi, M.; Rood, M.J.; Richardson, C.F.; Carey, T.R.; Chang, R.

    1998-01-01

    Coal-derived activated carbons (CDACs) were tested for their suitability in removing trace amounts of vapor-phase mercury from simulated flue gases generated by coal combustion. CDACs were prepared in bench-scale and pilot-scale fluidized-bed reactors with a three-step process, including coal preoxidation, carbonization, and then steam activation. CDACs from high-organicsulfur Illinois coals had a greater equilibrium Hg0 adsorption capacity than activated carbons prepared from a low-organic-sulfur Illinois coal. When a low-organic-sulfur CDAC was impregnated with elemental sulfur at 600 ??C, its equilibrium Hg0 adsorption capacity was comparable to the adsorption capacity of the activated carbon prepared from the high-organicsulfur coal. X-ray diffraction and sulfur K-edge X-ray absorption near-edge structure examinations showed that the sulfur in the CDACs was mainly in organic forms. These results suggested that a portion of the inherent organic sulfur in the starting coal, which remained in the CDACs, played an important role in adsorption of Hg0. Besides organic sulfur, the BET surface area and micropore area of the CDACs also influenced Hg0 adsorption capacity. The HgCl2 adsorption capacity was not as dependent on the surface area and concentration of sulfur in the CDACs as was adsorption of Hg0. The properties and mercury adsorption capacities of the CDACs were compared with those obtained for commercial Darco FGD carbon.

  19. Experimental kinetic parameters in the thermo-fluid-dynamic modelling of coal combustion

    International Nuclear Information System (INIS)

    Migliavacca, G.; Perini, M.; Parodi, E.

    2001-01-01

    The designing and the optimisation of modern and efficient combustion systems are nowadays frequently based on calculation tools for mathematical modelling, which are able to predict the evolution of the process starting from the first principles of physics. Otherwise, in many cases, specific experimental parameters are needed to describe the specific nature of the materials considered in the calculations. It is especially true in the modelling of coal combustion, which is a complex process strongly dependent on the chemical and physical features of the fuel. This paper describes some experimental techniques used to estimate the fundamental kinetic parameters of coal combustion and shows how this data may be introduced in a model calculation to predict the pollutant emissions from a real scale combustion plant [it

  20. A Pulverized Coal-Fired Boiler Optimized for Oxyfuel Combustion Technology

    Directory of Open Access Journals (Sweden)

    Tomáš Dlouhý

    2012-01-01

    Full Text Available This paper presents the results of a study on modifying a pulverized coal-fired steam boiler in a 250 MWe power plant for oxygen combustion conditions. The entry point of the study is a boiler that was designed for standard air combustion. It has been proven that simply substituting air by oxygen as an oxidizer is not sufficient for maintaining a satisfactory operating mode, not even with flue gas recycling. Boiler design optimization aggregating modifications to the boiler’s dimensions, heating surfaces and recycled flue gas flow rate, and specification of a flue gas recycling extraction point is therefore necessary in order to achieve suitable conditions for oxygen combustion. Attention is given to reducing boiler leakage, to which external pre-combustion coal drying makes a major contribution. The optimization is carried out with regard to an overall power plant conception for which a decrease in efficiency due to CO2 separation is formulated.

  1. Geochemical database of feed coal and coal combustion products (CCPs) from five power plants in the United States

    Science.gov (United States)

    Affolter, Ronald H.; Groves, Steve; Betterton, William J.; William, Benzel; Conrad, Kelly L.; Swanson, Sharon M.; Ruppert, Leslie F.; Clough, James G.; Belkin, Harvey E.; Kolker, Allan; Hower, James C.

    2011-01-01

    The principal mission of the U.S. Geological Survey (USGS) Energy Resources Program (ERP) is to (1) understand the processes critical to the formation, accumulation, occurrence, and alteration of geologically based energy resources; (2) conduct scientifically robust assessments of those resources; and (3) study the impacts of energy resource occurrence and (or) their production and use on both the environment and human health. The ERP promotes and supports research resulting in original, geology-based, non-biased energy information products for policy and decision makers, land and resource managers, other Federal and State agencies, the domestic energy industry, foreign governments, non-governmental groups, and academia. Investigations include research on the geology of oil, gas, and coal, and the impacts associated with energy resource occurrence, production, quality, and utilization. The ERP's focus on coal is to support investigations into current issues pertaining to coal production, beneficiation and (or) conversion, and the environmental impact of the coal combustion process and coal combustion products (CCPs). To accomplish these studies, the USGS combines its activities with other organizations to address domestic and international issues that relate to the development and use of energy resources.

  2. The chemical transformation of calcium in Shenhua coal during combustion in a muffle furnace

    Energy Technology Data Exchange (ETDEWEB)

    Tian, Sida [North China Electric Power Univ., Beijing (China). School of Energy, Power and Mechanical Engineering; Ministry of Education, Beijing (China). Key Lab. of Condition Monitoring and Control for Power Plant Equipment; Zhuo, Yuqun; Chen, Changhe [Tsinghua Univ., Beijing (China). Dept. of Thermal Engineering; Ministry of Education, Beijing (China). Key Lab. for Thermal Science and Power Engineering; Shu, Xinqian [China Univ. of Mining and Technology, Beijing (China). School of Chemical and Environmental Engineering

    2013-07-01

    The chemical reaction characteristics of calcium in three samples of Shenhua coal, i.e. raw sample, hydrochloric acid washed sample and hydrochloric acid washed light fraction, during combustion in a muffle furnace have been investigated in this paper. Ca is bound by calcite and organic matter in Shenhua coal. X ray diffraction (XRD) phase analysis has been conducted to these samples' combustion products obtained by heating at different temperatures. It has been found that the organically-bound calcium could easily react with clays and transform into gehlenite and anorthite partially if combusted under 815 C, whilst the excluded minerals promoted the conversion of gehlenite to anorthite. Calcite in Shenhua coal decomposed into calcium oxide and partially transformed into calcium sulfate under 815 C, and formed gehlenite and anorthite under 1,050 C. Calcite and other HCl-dissolved minerals in Shenhua coal were responsible mainly for the characteristic that the clay minerals in Shenhua coal hardly became mullite during combustion.

  3. Formation of the gaseous phase of impurity elements from coal combustion at a thermal power plant

    International Nuclear Information System (INIS)

    Kizil'shtein, L.Ya.; Levchenko, S.V.; Peretyakt'ko, A.G.

    1991-01-01

    Data are reported on the distribution of impurity elements in their principal carriers: organic matter, iron sulfides, and clays. Tests with high-temperature combustion of coals and argillites indicate that elements associated with clay minerals largely remain in ash and slag. They do not pass to the gas phase - a factor to be considered in assessment of environmental impact from thermal power plants and specification of toxic concentration levels of impurity elements in coal

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

    Science.gov (United States)

    Kapustyanskii, A. A.

    2017-07-01

    Changes in the structure of the fuel consumption by the thermal power stations of Ukraine caused by failure in supplying anthracite from the Donets Basin are analyzed and the major tasks of maintaining the functioning of the coal industry are formulated. The possibility of using, in the near future, the flame combustion of off-design solid fuels in the power boilers of the thermal power plants and combined heat and power plants is studied. The article presents results of expert tests of the TPP-210A and TP-15 boilers under flame combustion of mixtures of anthracites, lean coal, and the coal from the RSA in various combinations. When combusting, such mixtures have higher values of the combustibles yield and the ash fusibility temperature. The existence of the synergetic effect in the flame combustion of binary coal blends with different degrees of metamorphism is discussed. A number of top-priority measures have been worked out that allow for switching over the boilers designed to be fired with anthracite to using blends of coals of different ranks. Zoned thermal analysis of the TP-15 boiler furnace was performed for numerical investigation of the temperature distribution between the furnace chamber zones and exploration of the possibility of the liquid slag disposal and the temperature conditions for realization of this process. A positive result was achieved by combusting anthracite culm (AC), the coal from the RSA, and their mixtures with lean coal within the entire range of the working loads of the boilers in question. The problems of normalization of the liquid slag flow were also successfully solved without closing the slag notch. The results obtained by balance experiments suggest that the characteristics of the flame combustion of a binary blend, i.e., the temperature conditions in the furnace, the support flame values, and the degree of the fuel burnout, are similar to the characteristics of the flame of the coal with a higher reactive capacity, which

  5. Decommissioning Combustible Waste Treatment using Oxygen-Enriched Incinerator

    Energy Technology Data Exchange (ETDEWEB)

    Min, Byungyoun; Lee, Yoonji; Yun, Gyoungsu; Lee, Kiwon; Moon, Jeikwon [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2014-05-15

    The aim of the paper is current status of treatment for the decommissioning combustible waste in KAERI and for the purpose of the volume reduction and clearance for decommissioning combustible wastes generated by the decommissioning projects. The incineration technology has been selected for the treatment of combustible wastes. About 34 tons of decommissioning combustible waste has been treated using Oxygen Enriched incineration. Temperature, pressure of major components, stack gas concentration, i. e., SOx, NOx, CO, CO{sub 2} and HCl, and the residual oxygen were measured. Measured major parameters during normal operation were sustained on a stable status within a criteria operation condition. Oxygen enriched air, 22vol. % (dry basis) was used for stable incineration. The volume reduction ratio has achieved about 1/117. The incineration with decommissioning radioactive combustible waste is possible with moderate oxygen enrichment of 22 vol.% (dry basis) into the supply air. The incineration facility operated quite smoothly through the analysis major critical parameters of off-gas. The pressure, off-gas flow and temperature of major components remained constant within the range specified. The measures gases and particulate materials in stack were considerably below the regulatory limits. The achieved volume reduction ratio through incineration is about 1/117.

  6. Thermal analysis and kinetics of coal during oxy-fuel combustion

    Science.gov (United States)

    Kosowska-Golachowska, Monika

    2017-08-01

    The pyrolysis and oxy-fuel combustion characteristics of Polish bituminous coal were studied using non-isothermal thermogravimetric analysis. Pyrolysis tests showed that the mass loss profiles were almost similar up to 870°C in both N2 and CO2 atmospheres, while further mass loss occurred in CO2 atmosphere at higher temperatures due to char-CO2 gasification. Replacement of N2 in the combustion environment by CO2 delayed the combustion of bituminous coal. At elevated oxygen levels, TG/DTG profiles shifted through lower temperature zone, ignition and burnout temperatures decreased and mass loss rate significantly increased and complete combustion was achieved at lower temperatures and shorter times. Kinetic analysis for the tested coal was performed using Kissinger-Akahira-Sunose (KAS) method. The activation energies of bituminous coal combustion at the similar oxygen content in oxy-fuel with that of air were higher than that in air atmosphere. The results indicated that, with O2 concentration increasing, the activation energies decreased.

  7. Combustion characteristics and kinetic analysis of pulverized coal under different pressure grades

    Directory of Open Access Journals (Sweden)

    Qiwei ZUO

    2016-02-01

    Full Text Available By using thermo gravimetric balance, experimental research on combustion characteristics and dynamics parameters of the typical coal injection from some domestic steelworks are conducted with non-isothermal method. The combustion characteristic parameters of the sample pulverized coal such as ignition temperature, peak temperature at maximum weight loss rate, burnout temperature, general burn exponent(S, and maximum combustion rate are studied under pressure grades of 0.1, 1.1, 2.1, 3.1 and 4.1 MPa, the activation energy (E and pre-exponential factor in the combustion process are calculated. The results show that when the pressure increases from 0.1 to 4.1 MPa, ignition temperature decreases by 85.7 K at most, peak temperature at maximum weight loss rate decreases by 249.3 K at most, burnout temperature decreases by 375 K at most, maximum weight loss rate increases by 10 times, and S increases by 33.6 times at most. It is also shown that there exists a kinetic complementation between E and ln A from the view point of dynamics, and the critical pressure of pulverized coal reaction control requirement and combustion mode transform is 3.1 MPa for the pulverized coal.

  8. 40 CFR 60.1010 - Does this subpart apply to my municipal waste combustion unit?

    Science.gov (United States)

    2010-07-01

    ... waste combustion unit? 60.1010 Section 60.1010 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Performance for Small Municipal Waste Combustion Units for Which Construction is Commenced After August 30....1010 Does this subpart apply to my municipal waste combustion unit? Yes, if your municipal waste...

  9. Measurement of alkali-vapor emission from pressurized fluidized-bed combustion of Illinois coals

    Energy Technology Data Exchange (ETDEWEB)

    Lee, S.H.D.; Teats, F.G.; Swift, W.M. (Argonne National Lab., IL (United States)); Banerjee, D.D. (Illinois Clean Coal Inst., Carterville, IL (United States))

    1993-01-01

    Two Illinois Herrin No. 6 coals and one Illinois Springfield No. 5 coal were separately combusted in a laboratory-scale (15-cm dia) pressurized fluidized-bed combustor (PFBC) combined with an alkali sorber. These coals were combusted in a fluidized bed of Tymochtee dolomite at temperatures ranging from 910 to 950[degree]C and a system pressure of 9.2 atm absolute. Alkali-vapor emission (Na and K) in the PFBC flue gas was determined by the analytical activated-bauxite sorber bed technique developed at Argonne National Laboratory. The test results showed that sodium is the major alkali-vapor species present in the PFBC flue gas, and that the level of sodium-vapor emission increases linearly with both Na and Cl contents in the coals. This suggests that the sodium-vapor emission results from direct vaporization of NaCl present in the coals. The measured alkali-vapor concentration (Na + K), 67 to 190 ppbW, is more than 2.5 times greater than the allowable alkali limit of 24 ppb for an industrial gas turbine. Combusting these coals in a PFBC for power generation may require developing a method to control alkali vapors.

  10. Measurement of alkali-vapor emission from pressurized fluidized-bed combustion of Illinois coals

    Energy Technology Data Exchange (ETDEWEB)

    Lee, S.H.D.; Teats, F.G.; Swift, W.M. [Argonne National Lab., IL (United States); Banerjee, D.D. [Illinois Clean Coal Inst., Carterville, IL (United States)

    1993-04-01

    Two Illinois Herrin No. 6 coals and one Illinois Springfield No. 5 coal were separately combusted in a laboratory-scale (15-cm dia) pressurized fluidized-bed combustor (PFBC) combined with an alkali sorber. These coals were combusted in a fluidized bed of Tymochtee dolomite at temperatures ranging from 910 to 950{degree}C and a system pressure of 9.2 atm absolute. Alkali-vapor emission (Na and K) in the PFBC flue gas was determined by the analytical activated-bauxite sorber bed technique developed at Argonne National Laboratory. The test results showed that sodium is the major alkali-vapor species present in the PFBC flue gas, and that the level of sodium-vapor emission increases linearly with both Na and Cl contents in the coals. This suggests that the sodium-vapor emission results from direct vaporization of NaCl present in the coals. The measured alkali-vapor concentration (Na + K), 67 to 190 ppbW, is more than 2.5 times greater than the allowable alkali limit of 24 ppb for an industrial gas turbine. Combusting these coals in a PFBC for power generation may require developing a method to control alkali vapors.

  11. Managing ash from the combustion of solid waste

    International Nuclear Information System (INIS)

    Hauser, R.

    1992-01-01

    This paper reports that with millions of tons of refuse being combusted each year, increasing concern over the environment impact of the residue produced has caused both regulators and the resource recovery industry to address the technical and regulatory issues relating to the safe handling and disposal of ash. The basic issue concerning solid waste combustion ash management in this country is how, based on past, recent, and ongoing scientific research, solid waste combustion ash should be handled. Typically, refuse contains approximately 20 to 25 percent residue, which is collected either on grates at the bottom of the combustion chamber or filtered from the exhaust gases by the air pollution control equipment. The fly ash component of the total residue stream is between 10 and 30 percent of the total residue while the bottom ash content ranges from 70 to 90 percent of the total weight, depending upon the air pollution control equipment utilized, especially acid gas scrubbing equipment

  12. Effects of catalysts on combustion characteristics and kinetics of coal-char blends

    Science.gov (United States)

    Hu, Yingjie; Wang, Zhiqiang; Cheng, Xingxing; Liu, Ming; Ma, Chunyuan

    2018-04-01

    The effects of Fe2O3, CaO, and MnO2 on the combustion characteristics and kinetics of coal-char blends were investigated using thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). The results indicated that catalysts exhibited positive effects on the combustion characteristics of coal-char blends, especially in the initial period of coal-char blends combustion. With catalysts addition (mass 1.5%), it could improves volatile matter release, and reduces ignition point, promotes char to begin burning under lower temperature. The ignition index (C) was increased, respectively, by 27% for Fe2O3, 6% for CaO, 11.3% for MnO2, and the combustion characteristic index ( S ) was increased respectively, by 29% for Fe2O3, 5% for CaO, 8.3% for MnO2. In addition, two kinetic models (R2 and F1) were adopted to calculate the kinetic parameters in different stage of combustion processes. The results showed that with Fe2O3 or CaO addition, the activation energy at second stage decreases from 86.0 KJ/mol to 76.92 KJ/mol and 75.12 KJ/mol, respectively. There are no obvious decreases at the third stage of samples combustion process.

  13. Comparative study of combustion product emissions of Pakistani coal briquettes and traditional Pakistani domestic fuels

    International Nuclear Information System (INIS)

    Wachter, E.A.; Gammage, R.B.; Haas, J.W. III; Wilson, D.L.; DePriest, J.C.; Wade, J.; Ahmad, N.; Sibtain, F.; Zahid Raza, M.

    1992-10-01

    A comparative emissions study was conducted on combustion products of various solid domestic cooking fuels; the objective was to compare relative levels of organic and inorganic toxic emissions from traditional Pakistani fuels (wood, wood charcoal, and dried animal dung) with manufactured low-rank coal briquettes (Lakhra and Sor- Range coals) under conditions simulating domestic cooking. A small combustion shed 12 m 3 internal volume, air exchange rate 14 h -1 was used to simulate south Asian cooking rooms. 200-g charges of the various fuels were ignited in an Angethi stove located inside the shed, then combusted to completion; effluents from this combustion were monitored as a function of time. Measurements were made of respirable particulates, volatile and semi-volatile organics, CO, SO 2 , and NO x . Overall it appears that emissions from coal briquettes containing combustion amendments (slaked lime, clay, and potassium nitrate oxidizer) are no greater than emissions from traditional fuels, and in some cases are significantly lower; generally, emissions are highest for all fuels in the early stages of combustion

  14. Status of Westinghouse coal-fueled combustion turbine programs

    International Nuclear Information System (INIS)

    Scalzo, A.J.; Amos, D.J.; Bannister, R.L.; Garland, R.V.

    1992-01-01

    Developing clean, efficient, cost effective coal utilization technologies for future power generation is an essential part of our National Energy Strategy. Westinghouse is actively developing power plants utilizing advanced gasification, atmospheric fluidized beds (AFB), pressurized fluidized beds (PFB), and direct firing technology through programs sponsored by the U.S. Dept. of Energy (DOE). The DOE Office of Fossil Energy is sponsoring the Direct Coal-Fired Turbine program. This paper presents the status of current and potential Westinghouse Power Generation Business Unit advanced coal-fueled power generation programs as well as commercial plans

  15. 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

  16. Fluidized bed combustion of refuse-derived fuel in presence of protective coal ash

    Energy Technology Data Exchange (ETDEWEB)

    Ferrer, Eduardo [CIRCE, Universidad de Zaragoza, Maria de Luna, 3, Zaragoza (Spain); Aho, Martti [VTT Processes, P.O. Box 1603, 40101 Jyvaeskylae (Finland); Silvennoinen, Jaani; Nurminen, Riku-Ville [Kvaerner Power, P.O.Box 109, FIN-33101 Tampere (Finland)

    2005-12-15

    Combustion of refuse-derived fuel (RDF) alone or together with other biomass leads to superheater fouling and corrosion in efficient power plants (with high steam values) due to vaporization and condensation of alkali chlorides. In this study, means were found to raise the portion of RDF to 40% enb without risk to boilers. This was done by co-firing RDF with coal and optimizing coal quality. Free aluminum silicate in coal captured alkalies from vaporized alkali chlorides preventing Cl condensation to superheaters. Strong fouling and corrosion were simultaneously averted. Results from 100 kW and 4 MW CFB reactors are reported. (author)

  17. Integrated engineering and cost model for management of coal combustion byproducts

    Energy Technology Data Exchange (ETDEWEB)

    Sevim, H. [Department of Mining Engineering, Southern Illinois University at Carbondale, Carbondale, Illinois (United States); Renninger, S. [US Department of Energy, Morgantown Energy Technology Center, Morgantown, West Virginia (United States)

    1998-07-01

    An integrated engineering and cost model has been developed as a part of an overall research project for exploring the technical, environmental and economic feasibility of disposing coal combustion byproducts and flue gas desulfurisation products in underground coal mines in Illinois. The features of the model have been keyed in user-friendly software. In this paper, the purpose and the structure of the model are described. The capabilities of the software are illustrated through an example involving transportation of byproducts in containers from a power plant to a mine site, and subsequent placement of the byproducts in a abandoned underground coal mine using a hydraulic injection system. 3 refs.

  18. Strength and corrosion behavior of SiC - based ceramics in hot coal combustion environments

    Energy Technology Data Exchange (ETDEWEB)

    Breder, K.; Parten, R.J. [Oak Ridge National Lab., TN (United States)

    1996-08-01

    As part of an effort to evaluate the use of advanced ceramics in a new generation of coal-fired power plants, four SiC-based ceramics have been exposed to corrosive coal slag in a laboratory furnace and two pilot scale combustors. Initial results indicate that the laboratory experiments are valuable additions to more expensive pilot plant experiments. The results show increased corrosive attack with increased temperature, and that only slight changes in temperature may significantly alter the degree of strength degradation due to corrosive attack. The present results are part of a larger experimental matrix evaluating the behavior of ceramics in the coal combustion environment.

  19. 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.

  20. Thermodynamic evaluation of chemical looping combustion for combined cooling heating and power production driven by coal

    International Nuclear Information System (INIS)

    Fan, Junming; Hong, Hui; Zhu, Lin; Wang, Zefeng; Jin, Hongguang

    2017-01-01

    Highlights: • An ex-situ coal gasification chemical looping combustion integrated with CCHP process has been presented. • This novel process maintains a maximum energy efficiency of 60.34%. • The fossil energy saving ratio of this process is optimize to be 27.20%. - Abstract: This study carries out an investigation concerning on the benefits of ex-situ coal gasification chemical looping combustion integrated with combined cooling, heating and power generation (CCHP-CLC) by means of thermodynamic evaluation. The coal gasification syngas is introduced into chemical looping combustion for inherent separation of CO_2 without extra energy consumed. The combustion flue gases from both air reactor and fuel reactor are sequentially fed into gas turbines for electricity production, a heat recovery vapor generator unit for further electricity generation with driving a LiBr-H_2O absorption chiller for cooling production in summer and finally a heat exchanger for daily heat water production. A preliminary parameter analysis helps to obtain the optimum operating condition, as steam-to-coal ratio (S/C) of 0.05, oxygen-to-coal ratio (O/C) of 0.75, and operating pressure of chemical looping combustion process of 5 bar. The overall energy efficiency of the CCHP-CLC process is calculated equal to 58.20% in summer compared with that of 60.34% in winter. Importantly, by utilization of such process, the reduction potential of fossil fuel (coal) consumption has been demonstrated to be 23.36% in summer and 27.20% in winter.

  1. Bermudagrass sod growth and metal uptake in coal combustion by-product-amended media

    Energy Technology Data Exchange (ETDEWEB)

    Schlossberg, M.J.; Vanags, C.P.; Miller, W.P. [University of Georgia, Athens, GA (USA). Dept. of Crop & Soil Science

    2004-04-01

    Coal combustion by-products (CCB) include fly ash and bottom ash and are generated nationally at rates of 10{sup 8} Mg yr{sup -1}. Land applications of CCB have improved physicochemical properties of soil, yet inherent bulkiness and trace metal content of CCB often limit their use. Likewise, utilization of biosolids and manure as fertilizer can be problematic due to unfavorable nutrient ratios. A 2-yr field study evaluated environmental and technical parameters associated with CCB-organic waste utilization as growth media in turfgrass sod production. Experimental growth media formulated with CCB and organic waste and a sand-compost control mixture were uniformly spread at rates from 200 to 400 m{sup 3} ha{sup -1} and sprigged with hybrid bermudagrass (Cynodon dactylon (L.) Pers. x C. transvaalensis Burtt-Davy). Leaf clippings were collected and analyzed for total elemental content each year. In Year 2, growth media samples were collected during establishment 47 and 84 days after planting (DAP) and viable Escherichia coli organisms were quantified. At harvest (99 or 114 DAP), sod biomass and physicochemical properties of the growth media were measured. During sod propagation, micronutrient and metal content in leaf clippings varied by growth media and time. After 47 d of typical sod field management, viable E. coli pathogens were detected in only one biosolids-amended plot. No viable E. coli were measured at 84 DAP. In both years, sod biomass was greatest in media containing biosolids and fly ash. Following installation of sod, evaluations did not reveal differences by media type or application volume. Using CCB-organic waste mixes at the rates described herein is a rapid and environmentally safe method of bermudagrass sod production.

  2. Process to improve combustion and coalescing characteristics of coal pellets

    Energy Technology Data Exchange (ETDEWEB)

    Ban, T.E.; Marlowe, W.H.

    1980-10-23

    Baking types of coal, which occur mainly in the Midwestern States of the USA, tend to form solid layers when heated to remove tar. In order to prevent this, it is proposed to pulverize the coal, to form small pellets and to coat these pellets. A suitable coating material mentioned here is sodium carbonate. Variants of the coating process are given. The coated pellets are heated.

  3. Soot, organics, and ultrafine ash from air- and oxy-fired coal combustion

    KAUST Repository

    Andersen, Myrrha E.

    2016-10-19

    Pulverized bituminous coal was burned in a 10. W externally heated entrained flow furnace under air-combustion and three oxy-combustion inlet oxygen conditions (28, 32, and 36%). Experiments were designed to produce flames with practically relevant stoichiometric ratios (SR. =1.2-1.4) and constant residence times (2.3. s). Size-classified fly ash samples were collected, and measurements focused on the soot, elemental carbon (EC), and organic carbon (OC) composition of the total and ultrafine (<0.6. μm) fly ash. Results indicate that although the total fly ash carbon, as measured by loss on ignition, was always acceptably low (<2%) with all three oxy-combustion conditions lower than air-combustion, the ultrafine fly ash for both air-fired and oxy-fired combustion conditions consists primarily of carbonaceous material (50-95%). Carbonaceous components on particles <0.6. μm measured by a thermal optical method showed that large fractions (52-93%) consisted of OC rather than EC, as expected. This observation was supported by thermogravimetric analysis indicating that for the air, 28% oxy, and 32% oxy conditions, 14-71% of this material may be OC volatilizing between 100. C and 550. C with the remaining 29-86% being EC/soot. However, for the 36% oxy condition, OC may comprise over 90% of the ultrafine carbon with a much smaller EC/soot contribution. These data were interpreted by considering the effects of oxy-combustion on flame attachment, ignition delay, and soot oxidation of a bituminous coal, and the effects of these processes on OC and EC emissions. Flame aerodynamics and inlet oxidant composition may influence emissions of organic hazardous air pollutants (HAPs) from a bituminous coal. During oxy-coal combustion, judicious control of inlet oxygen concentration and placement may be used to minimize organic HAP and soot emissions.

  4. Natural radionuclides in coal and waste material originating from coal fired power plant

    International Nuclear Information System (INIS)

    Marovic, Gordana; Franic, Zdenko; Sencar, Jasminka; Petrinec, Branko; Bituh, Tomislav; Kovac, Jadranka

    2008-01-01

    This paper presents long-term investigations of natural radioactivity in coal, used for power production in the coal-fired power plant (CFPP) situated on the Adriatic coast, and resulting slag and ash. Activity concentrations of 40 K, 232 Th, 226 Ra and 238 U in used coal and resulting waste material have been measured for 25 years. As expected, it was demonstrated that the content of radionuclides in deposited bottom and filter ash material are closely related with radionuclide activity concentrations and mineral matter fraction in used coals. The external hazard index has been calculated and discussed for the slag and ash depository. During the first decade of operation of the CFPP has been used domestic coal produced in nearby area characterized by higher background radiation compared with the rest of Croatia. Therefore, the coal itself had relatively high 226 Ra and 238 U activity concentrations while potassium and thorium content was very low, 40 K activity concentrations being 2-9% and those of 232 Th 1-3% of total activity. As, in addition, the sulphur concentrations in coal were very high use of domestic coal was gradually abandoned till it was completely substituted by imported coal originated from various sources and of low natural radioactivity. Upon this, activity concentrations of uranium series radionuclides in deposited waste materials decreased significantly. Consequently, waste material i.e., slag and ash, generated in the last several years of coal fired power plant operation could be readily used in cement industry and as additive to other building materials, without any special restrictions according to the Croatian regulations dealing with building materials and European directives. (author)

  5. Burning characteristics and gaseous/solid emissions of blends of pulverized coal with waste tire-derived fuel

    Energy Technology Data Exchange (ETDEWEB)

    Levendis, Y.A.; Atal, A.; Courtemanche, B.; Carlson, J.B. [Northeastern University, Boston, MA (United States). Dept. of Mechanical, Industrial and Manufacturing Engineering

    1998-10-01

    The combustion behaviour and the emissions from blends of a pulverized bituminous coal and ground waste automobile tires were investigated. Combustion took place under steady flow conditions, in an electrically-heated drop-tube furnace in air at a gas temperature of 1150{degree}C and a particle heating rate of approximate to 10{sup 5}{degree}C/s. Combustion observations were conducted with simultaneous pyrometry and cinematography. Interparticle flame interactions were visually observed in the near-stoichiometric and fuel-rich regions. Volatile flame interactions were apparent at a lower phi for tire crumb particles than for coal particles and became progressively more intense with increasing phi until at sufficiently high phi`s large group flames formed for tire particles. As particle flame interactions increased, average maximum temperatures in the flame decreased. Coal particles resisted the formation of group flames, even at high phi`s. Such observations correlated with the trends observed for the PAH emissions of the two fuels, those of tire crumb being much higher than those of coal Some stratification in the combustion of blends of particles of the two fuels was observed. This kept the PAH emissions lower levels than expected. NO{sub x} emissions from tires were much lower than those of coal, while those of the blends were close to the weighted average emissions. SO{sub 2} emissions from the blends were close to the weighted average emissions of the two fuels. Blending coal with tire reduced the CO{sub 2} emissions of coal but increased the CO emissions. Particulate emissions (soot and ash), measured in the range of 0.4 to 8{mu}m, increased with phi. Generally, tire produced more mass of submicron particulates than coal. Particulate emissions of blends of the two fuels were close to those expected based on weighted average of the two fuels.

  6. Processing of combustible radioactive waste using incineration techniques

    International Nuclear Information System (INIS)

    Maestas, E.

    1981-01-01

    Among the OECD Nuclear Energy Agency Member countries numerous incineration concepts are being studied as potential methods for conditioning alpha-bearing and other types of combustible radioactive waste. The common objective of these different processes is volume reduction and the transformation of the waste to a more acceptable waste form. Because the combustion processes reduce the mass and volume of waste to a form which is generally more inert than the feed material, the resulting waste can be more uniformly compatible with safe handling, packaging, storage and/or disposal techniques. The number of different types of combustion process designed and operating specifically for alpha-bearing wastes is somewhat small compared with those for non-alpha radioactive wastes; however, research and development is under way in a number of countries to develop and improve alpha incinerators. This paper provides an overview of most alpha-incineration concepts in operation or under development in OECD/NEA Member countries. The special features of each concept are briefly discussed. A table containing characteristic data of incinerators is presented so that a comparison of the major programmes can be made. The table includes the incinerator name and location, process type, capacity throughput, operational status and application. (author)

  7. Coal option. [Shell Co

    Energy Technology Data Exchange (ETDEWEB)

    1978-01-01

    This paper notes the necessity of developing an international coal trade on a very large scale. The role of Shell in the coal industry is examined; the regions in which Shell companies are most active are Australia, Southern Africa, Indonesia; Europe and North America. Research is being carried out on marketing and transportation, especially via slurry pipelines; coal-oil emulsions; briquets; fluidized-bed combustion; recovery of coal from potential waste material; upgrading of low-rank coals; unconventional forms of mining; coal conversion (the Shell/Koppers high-pressure coal gasification process). Techniques for cleaning flue gas (the Shell Flue Gas Desulfurization process) are being examined.

  8. 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.

  9. Management of high sulfur coal combustion residues, issues and practices: Proceedings

    Energy Technology Data Exchange (ETDEWEB)

    Chugh, Y.P.; Beasley, G.A. [eds.

    1994-10-01

    Papers presented at the following sessions are included in this proceedings: (1) overview topic; (2) characterization of coal combustion residues; (3) environmental impacts of residues management; (4) materials handling and utilization, Part I; and (5) materials handling and utilization, Part II. Selected paper have been processed separately for inclusion in the Energy Science and Technology Database.

  10. Influence of quality coal combustion and domestic stoves outbreaks steam generators and the environmental pollution

    OpenAIRE

    Petrilean, Dan Codrut

    2008-01-01

    It was drawn balance a steam generator. We determined the pollutant emissions from coal combustion in the furnace Jiu Valley steam generator with an output of 150 MW. As an example of the steam generator was considered the type BabkoK Hitachi with turbine Turbao + Atom, in cogeneration.

  11. The critical assessment of the carbon dioxide purification technologies after Oxyfuel combustion of coals

    International Nuclear Information System (INIS)

    Iovchev, M.; Gadjanov, P.; Tzvetkov, N.

    2012-01-01

    The critical assessment of the two carbon dioxide purification technologies after Oxyfuel - combustion of coals are discussed in the report. It is noticed that these technologies proposed by 'Foster Wheeler' and 'Air Products' companies are under development now (2012) and their presence in the international market is to be expected in the next years. (authors)

  12. Presentation of the health impact evaluation study of atmospheric emissions of a major coal combustion installation

    International Nuclear Information System (INIS)

    Bonnard, R.

    2004-12-01

    In the framework of a working group on the major installations, a study has been realized on a today coal combustion installation. The direct risk by inhalation and the risks bond to indirect exposure of atmospheric releases were analyzed. The calculation method is explained and the uncertainties are discussed to present the results. (A.L.B.)

  13. Analysis of Index Gases of Coal Spontaneous Combustion Using Fourier Transform Infrared Spectrometer

    Directory of Open Access Journals (Sweden)

    Xiaojun Tang

    2014-01-01

    Full Text Available Analysis of the index gases of coal for the prevention of spontaneous combustion is of great importance for the enhancement of coal mine safety. In this work, Fourier Transform Infrared Spectrometer (FTIRS is presented to be used to analyze the index gases of coal in real time to monitor spontaneous combustion conditions. Both the instrument parameters and the analysis method are introduced at first by combining characteristics of the absorption spectra of the target analyte with the analysis requirements. Next, more than ten sets of the gas mixture containing ten components (CH4, C2H6, C3H8, iso-C4H10, n-C4H10, C2H4, C3H6, C2H2, CO, and CO2 are included and analyzed with a Spectrum Two FTIRS made by Perkin Elmer. The testing results show that the detection limit of most analytes is less than 2×10-6. All the detection limits meet the monitoring requirements of coal spontaneous combustion in China, which means that FTIRS may be an ideal instrument and the analysis method used in this paper is sufficient for spontaneous combustion gas monitoring on-line and even in situ, since FTIRS has many advantages such as fast analysis, being maintenance-free, and good safety.

  14. Sulfur emission from Victorian brown coal under pyrolysis, oxy-fuel combustion and gasification conditions.

    Science.gov (United States)

    Chen, Luguang; Bhattacharya, Sankar

    2013-02-05

    Sulfur emission from a Victorian brown coal was quantitatively determined through controlled experiments in a continuously fed drop-tube furnace under three different atmospheres: pyrolysis, oxy-fuel combustion, and carbon dioxide gasification conditions. The species measured were H(2)S, SO(2), COS, CS(2), and more importantly SO(3). The temperature (873-1273 K) and gas environment effects on the sulfur species emission were investigated. The effect of residence time on the emission of those species was also assessed under oxy-fuel condition. The emission of the sulfur species depended on the reaction environment. H(2)S, SO(2), and CS(2) are the major species during pyrolysis, oxy-fuel, and gasification. Up to 10% of coal sulfur was found to be converted to SO(3) under oxy-fuel combustion, whereas SO(3) was undetectable during pyrolysis and gasification. The trend of the experimental results was qualitatively matched by thermodynamic predictions. The residence time had little effect on the release of those species. The release of sulfur oxides, in particular both SO(2) and SO(3), is considerably high during oxy-fuel combustion even though the sulfur content in Morwell coal is only 0.80%. Therefore, for Morwell coal utilization during oxy-fuel combustion, additional sulfur removal, or polishing systems will be required in order to avoid corrosion in the boiler and in the CO(2) separation units of the CO(2) capture systems.

  15. 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.

  16. 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.

  17. Some environmental aspects related to sulphur emissions during combustion of Bulgarian coals

    International Nuclear Information System (INIS)

    Vassileva, C.; Vassilev, S.

    2004-01-01

    The mechanism of S emissions and their capture during combustion of some Bulgarian coals (Maritza East, Maritza West, Sofia, Pernik, Bobov Dol, Balkan) was studied based on the phase-mineral transformations in the inorganic matter during gradual heating of these coals. It was found that: 1) the organic, elemental and sulphide S is released from coal at 200-700 0 C; 2) the volatile S is initially captured by intermediate Ca-, Mg-, K-, Na-, Fc-, and Ba-oxides (mainly from decomposed organic matter and carbonates) with formation of their sulphates at 200-1000 0 C; 3) the decomposition of original and newly-formed sulphates occurs at 800-1300 0 C and they are the major source of volatile SO 2 from stack emissions of thermoelectric power stations (TPSs). The described mechanism of S emissions and their capture indicates that the traditional pulverized combustion (1200-1600 0 C) of the high-sulphur Bulgarian coals in TPSs is inadequate from an environmental point of view and other alternatives should be applied. Some of them such as fluidized-bed combustion and selective blending of the coals are proposed

  18. A model of the enhancement of coal combustion using high intensity acoustic fields

    International Nuclear Information System (INIS)

    Yavuzkurt, S.; Ha, M.Y.; Koopmann, G.H.; Scaroni, A.

    1989-01-01

    In this paper a model for the enhancement of coal combustion in the presence of high intensity acoustics is developed. A high intensity acoustic field induces an oscillating velocity over pulverized coal particles otherwise entrained in the main gas stream, resulting in increased heat and mass transfer. The augmented heat and mass transfer coefficients, expressed as space- and time-averaged Nusselt and Sherwood numbers for the oscillating flow, were implemented in an existing computer code (PCGC-2) capable of predicting various aspects of pulverized coal combustion and gasification. Increases in the Nusselt and Sherwood numbers of about 45, 60 and 82.5% at sound pressure levels of 160, 165, and 170 dB for 100 μm coal particles were obtained due to increases in the acoustic slop velocity associated with the increased sound pressure levels. The main effect of the acoustic field was observed during the char combustion phase in a diffusionally controlled situation. A decrease in the char burnout length (time) of 15.7% at 160 dB and 30.2% at 170 dB was obtained compared to the case with no sound for the 100 μm coal particles

  19. Nitric oxide reduction in coal combustion: role of char surface complexes in heterogeneous reactions

    Energy Technology Data Exchange (ETDEWEB)

    Arenillas, A.; Rubiera, F.; Pis, J.J. [Instituto Nacional del Carbon, CSIC, Oviedo (Spain)

    2002-12-15

    Nitrogen oxides are one of the major environmental problems arising from fossil fuel combustion. Coal char is relatively rich in nitrogen, and so this is an important source of nitrogen oxides during coal combustion. However, due to its carbonaceous nature, char can also reduce NO through heterogeneous reduction. The objectives of this work were on one hand to compare NO emissions from coal combustion in two different types of equipment and on the other hand to study the influence of char surface chemistry on NO reduction. A series of combustion tests were carried out in two different scale devices: a thermogravimetric analyzer coupled to a mass spectrometer and an FTIR (TG-MS-FTIR) and a fluidized bed reactor with on-line battery of analyzers. According to the results obtained, it can be said that the TG-MS-FTIR system provides valuable information about NO heterogeneous reduction and it can give good trends of the behaviour in other combustion equipments, i.e. fluidized bed combustors. It has been also pointed out that NO-char interaction depends to a large extent on temperature. In the low-temperature range NO heterogeneous reduction seems to be controlled by the evolution of surface complexes. In the high-temperature range a different mechanism is involved in NO heterogeneous reduction, the nature of the carbon matrix being a key factor. 27 refs., 6 figs., 1 tab.

  20. Nitric oxide reduction in coal combustion: role of char surface complexes in heterogeneous reactions.

    Science.gov (United States)

    Arenillas, Ana; Rubiera, Fernando; Pis, José J

    2002-12-15

    Nitrogen oxides are one of the major environmental problems arising from fossil fuel combustion. Coal char is relatively rich in nitrogen, and so this is an important source of nitrogen oxides during coal combustion. However, due to its carbonaceous nature, char can also reduce NO through heterogeneous reduction. The objectives of this work were on one hand to compare NO emissions from coal combustion in two different types of equipment and on the other hand to study the influence of char surface chemistry on NO reduction. A series of combustion tests were carried out in two different scale devices: a thermogravimetric analyzer coupled to a mass spectrometer and an FTIR (TG-MS-FTIR) and a fluidized bed reactor with an on line battery of analyzers. The TG-MS-FTIR system was also used to perform a specific study on NO heterogeneous reduction reactions using chars with different surface chemistry. According to the results obtained, it can be said that the TG-MS-FTIR system provides valuable information about NO heterogeneous reduction and it can give good trends of the behavior in other combustion equipments (i.e., fluidized bed combustors). It has been also pointed out that NO-char interaction depends to a large extent on temperature. In the low-temperature range (800 degrees C), a different mechanism is involved in NO heterogeneous reduction, the nature of the carbon matrix being a key factor.

  1. Computational fluid dynamics simulation for chemical looping combustion of coal in a dual circulation fluidized bed

    International Nuclear Information System (INIS)

    Su, Mingze; Zhao, Haibo; Ma, Jinchen

    2015-01-01

    Highlights: • CFD simulation of a 5 kW_t_h CLC reactor of coal was conducted. • Gas leakage, flow pattern and combustion efficiency of the reactor was analyzed. • Optimal condition was achieved based on operation characteristics understanding. - Abstract: A dual circulation fluidized bed system is widely accepted for chemical looping combustion (CLC) for enriching CO_2 from the utilization of fossil fuels. Due to the limitations of the measurement, the details of multiphase reactive flows in the interconnected fluidized bed reactors are difficult to obtain. Computational Fluid Dynamics (CFD) simulation provides a promising method to understand the hydrodynamics, chemical reaction, and heat and mass transfers in CLC reactors, which are very important for the rational design, optimal operation, and scaling-up of the CLC system. In this work, a 5 kW_t_h coal-fired CLC dual circulation fluidized bed system, which was developed by our research group, was first simulated for understanding gas leakage, flow pattern and combustion efficiency. The simulation results achieved good agreement with the experimental measurements, which validates the simulation model. Subsequently, to improve the combustion efficiency, a new operation condition was simulated by increasing the reactor temperature and decreasing the coal feeding. An improvement in the combustion efficiency was attained, and the simulation results for the new operation condition were also validated by the experimental measurements in the same CLC combustor. All of the above processes demonstrated the validity and usefulness of the simulation results to improve the CLC reactor operation.

  2. Toward an understanding of coal combustion in blast furnace tuyere injection

    Energy Technology Data Exchange (ETDEWEB)

    John G. Mathieson; John S. Truelove; Harold Rogers [BlueScope Steel Research, Port Kembla, NSW (Australia)

    2005-07-01

    The former Broken Hill Proprietary Company Limited, along with its successors BlueScope Steel and BHP Billiton, like many of their iron and steel making counterparts, has had a long history of investigating pulverised coal injection and combustion under the conditions of blast furnace tuyere injection. A succession of pilot scale hot models and combustion test rigs have been constructed and operated at the company's Newcastle Laboratories beginning with the pilot scale hot raceway model in 1981. Each successive generation of test rig has attempted to provide a closer approximation to the actual blast furnace situation with the current test rig (1998 to present) seeking to promote an 'expanding' combusting coal plume. Test rig configuration is demonstrated to have a significant effect on coal burnout at a nominal transit time of 20 ms. The development of the combustion test rigs has been supported through the co-development of a range of sampling and measuring techniques and the application of a number of numerical combustion models. This paper reviews some of the milestones along the path of these investigations, the current understandings and what the future potentially holds. It's not solved yet! 17 refs., 11 figs.

  3. Treatment of alpha-bearing combustible wastes using acid digestion

    International Nuclear Information System (INIS)

    Lerch, R.E.; Allen, C.R.; Blasewitz, A.G.

    1977-11-01

    Acid digestion has been developed at the Hanford Engineering Development Laboratory (HEDL) in Richland, Washington to reduce the volume of combustible nuclear waste materials, while converting them to an inert, noncombustible residue. A 100 kg/day test unit has recently been constructed to demonstrate the process using radioactively contaminated combustible wastes. The unit, called the Radioactive Acid Digestion Test Unit (RADTU) was completed in September 1977 and is currently undergoing cold shakedown tests. Hot operation is expected in May 1978. Features of RADTU include: storage and transfer station for incoming wastes, a feed preparation station, an extrusion feed mechanism for transfer of the waste to the acid digester, the acid digester, a residue recovery system, and an off-gas treatment system

  4. Municipal solid waste combustion: Fuel testing and characterization

    Energy Technology Data Exchange (ETDEWEB)

    Bushnell, D.J.; Canova, J.H.; Dadkhah-Nikoo, A.

    1990-10-01

    The objective of this study is to screen and characterize potential biomass fuels from waste streams. This will be accomplished by determining the types of pollutants produced while burning selected municipal waste, i.e., commercial mixed waste paper residential (curbside) mixed waste paper, and refuse derived fuel. These materials will be fired alone and in combination with wood, equal parts by weight. The data from these experiments could be utilized to size pollution control equipment required to meet emission standards. This document provides detailed descriptions of the testing methods and evaluation procedures used in the combustion testing and characterization project. The fuel samples will be examined thoroughly from the raw form to the exhaust emissions produced during the combustion test of a densified sample.

  5. Treatment of alpha-bearing combustible wastes using acid digestion

    International Nuclear Information System (INIS)

    Lerch, R.E.; Allen, C.R.; Blasewitz, A.G.

    1978-01-01

    Acid digestion has been developed at the Hanford Engineering Development Laboratory (HEDL) in Richland, Washington to reduce the volume of combustible nuclear waste materials, while converting them to an inert, noncombustible residue. A 100 kg/day test unit has recently been constructed to demonstrate the process using radioactively contaminated combustible wastes. The unit, called the Radioactive Acid Digestion Test Unit (RADTU) was completed in September 1977 and is currently undergoing cold shakedown tests. Hot operation is expected in May 1978. Features of RADTU include: storage and transfer station for incoming wastes, a feed preparation station, an extrusion feed mechanism for transfer of the waste to the acid digester, the acid digester a residue recovery system, and an off-gas treatment system

  6. Experimental Studies on Combustion Characteristics of Mixed Municipal Solid Waste

    Institute of Scientific and Technical Information of China (English)

    Fan Jiang; Zhonggang Pan; Shi Liu; Haigang Wang

    2003-01-01

    In our country, municipal solid wastes (MSW) are always burnt in their original forms and only a few pretreatments are taken. Therefore it is vital to study the combustion characteristics of mixed waste. In this paper,thermogravimetric analysis and a lab scale fluidized bed facility were used as experimental means. The data in two different experimental systems were introduced and compared. It took MSW 3~3.5 rain to burn out in FB, but in thermogravimetric analyzer, the time is 20~25 min. It can be concluded that, in general, the behavior of a mixture of waste in TGA can be expressed by simple combination of individual components of the waste mixtures.Only minor deviations from the rule were observed. Yet, in Fluidized Bed, it was found that, for some mixtures,there was interference among the components during fluidized bed combustion.

  7. Efficiency and emissions of coal combustion in two unvented cookstoves

    International Nuclear Information System (INIS)

    Kaoma, J.; Kasali, G.B.; Ellegaard, A.

    1994-01-01

    An improved chamber method was employed in the evaluation of the energy conversion and emission characteristics of coal in two unvented cookstoves known as the clay stove and the Maamba stove. Burn rate and stove efficiency were determined together with mission factors for carbon monoxide (CO), nitric oxide (NO) and respirable suspended particulates (RSP). Compared to Maamba stove, the clay stove exhibited a lower burn rate but higher efficiency. The clay stove recorded mean CO, SO 2 , NO 2 , NO and RSP emission factors of 200, 47, 10, 0.4 and 2.4 g/kg, respectively. The Maamba stove emission factors for the same pollutants were 170, 36, n.d., 1.2 and 8.0 g/kg, respectively. The emissions and concentrations of carbon monoxide were less than those previously found with charcoal use, but still exceeded air pollution guidelines by orders of magnitude. Thus the use of coal would not constitute any appreciable improvement over the present charcoal use. Sulphur dioxide emissions and concentrations are quite high, and would constitute a new pollutant in residential areas of Zambia. Particulate emissions and concentrations from coal are higher than from charcoal. In view of specific health risks associated with particulates from coal smoke the domestic use of raw coal is not recommended. 16 refs, 8 figs, 20 tabs

  8. Experimental investigations on combustion and emission behaviour during oxy-coal combustion

    OpenAIRE

    Dhungel, Bhupesh

    2010-01-01

    As the most abundant non-renewable energy source available, coal has traditionally played a major role in ensuring the security of energy, and will continue to play a key role in the world energy mix. The burning of coal has however always been a subject of environmental concern. In recent years, the emission of green house gases and global climate change has emerged as the largest environmental challenge. As coal fired power plants are categorised among the least carbon efficient energy prod...

  9. Utilization of ash from municipal solid waste combustion

    Energy Technology Data Exchange (ETDEWEB)

    Jones, C.; Hahn, J.; Magee, B.; Yuen, N.; Sandefur, K.; Tom, J.; Yap, C.

    1999-09-01

    This ash study investigated the beneficial use of municipal waste combustion combined ash from the H-POWER facility in Oahu. These uses were grouped into intermediate cover for final closure of the Waipahu landfill, daily cover at the Waimanalo Gulch Landfill, and partial replacement for aggregate in asphalt for road paving. All proposed uses examine combined fly and bottom ash from a modern waste-to-energy facility that meets requirements of the Clean Air Act Amendments for Maximum Achievable Control Technology.

  10. Characterization, leachability and valorization through combustion of residual chars from gasification of coals with pine.

    Science.gov (United States)

    Galhetas, Margarida; Lopes, Helena; Freire, Márcia; Abelha, Pedro; Pinto, Filomena; Gulyurtlu, Ibrahim

    2012-04-01

    This paper presents the study of the combustion of char residues produced during co-gasification of coal with pine with the aim of characterizing them for their potential use for energy. These residues are generally rich in carbon with the presence of other elements, with particular concern for heavy metals and pollutant precursors, depending on the original fuel used. The evaluation of environmental toxicity of the char residues was performed through application of different leaching tests (EN12457-2, US EPA-1311 TCLP and EA NEN 7371:2004). The results showed that the residues present quite low toxicity for some of pollutants. However, depending on the fuel used, possible presence of other pollutants may bring environmental risks. The utilization of these char residues for energy was in this study evaluated, by burning them as a first step pre-treatment prior to landfilling. The thermo-gravimetric analysis and ash fusibility studies revealed an adequate thermochemical behavior, without presenting any major operational risks. Fluidized bed combustion was applied to char residues. Above 700°C, very high carbon conversion ratios were obtained and it seemed that the thermal oxidation of char residues was easier than that of the coals. It was found that the char tendency for releasing SO(2) during its oxidation was lower than for the parent coal, while for NO(X) emissions, the trend was observed to increase NO(X) formation. However, for both pollutants the same control techniques might be applied during char combustion, as for coal. Furthermore, the leachability of ashes resulting from the combustion of char residues appeared to be lower than those produced from direct coal combustion. Copyright © 2011 Elsevier Ltd. All rights reserved.

  11. 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.

  12. Particle size distribution of fly ash from co-incineration of bituminous coal with municipal solid waste

    Directory of Open Access Journals (Sweden)

    Cieślik Ewelina

    2018-01-01

    Full Text Available One of the source of air pollutants is emission from local coal-fired boiler-houses and domestic heating boilers. The consequence of incineration of municipal waste is the introduction of additional pollutants into the atmosphere, including fly ash. The aim of this work was to evaluate the particle size distribution of fly ash emitted by coal combustion and co-incineration of coal with municipal waste in a domestic 18 kW central heating boiler equipped with an automatic fuel feeder. Mixtures of bituminous coal with different types of solid waste (5, 10 and 15% of mass fraction were used. Solid waste types consisted of: printed, colored PE caps, fragmented cable trunking, fragmented car gaskets and shredded tires from trucks. During the incineration of a given mixture of municipal waste with bituminous coal, the velocity of exhaust gas was specified, the concentration and mass flow of fly ash were determined together with the physico-chemical parameters of the exhaust gas, the samples of emitted fly ash were taken as the test material. Particle size analysis of fly ash was performed using laser particle sizer Fritch Analysette 22. The PM10 share from all fly ashes from incineration of mixtures was about 100%. Differences were noted between PM2.5 and PM1.

  13. Particle size distribution of fly ash from co-incineration of bituminous coal with municipal solid waste

    Science.gov (United States)

    Cieślik, Ewelina; Konieczny, Tomasz; Bobik, Bartłomiej

    2018-01-01

    One of the source of air pollutants is emission from local coal-fired boiler-houses and domestic heating boilers. The consequence of incineration of municipal waste is the introduction of additional pollutants into the atmosphere, including fly ash. The aim of this work was to evaluate the particle size distribution of fly ash emitted by coal combustion and co-incineration of coal with municipal waste in a domestic 18 kW central heating boiler equipped with an automatic fuel feeder. Mixtures of bituminous coal with different types of solid waste (5, 10 and 15% of mass fraction) were used. Solid waste types consisted of: printed, colored PE caps, fragmented cable trunking, fragmented car gaskets and shredded tires from trucks. During the incineration of a given mixture of municipal waste with bituminous coal, the velocity of exhaust gas was specified, the concentration and mass flow of fly ash were determined together with the physico-chemical parameters of the exhaust gas, the samples of emitted fly ash were taken as the test material. Particle size analysis of fly ash was performed using laser particle sizer Fritch Analysette 22. The PM10 share from all fly ashes from incineration of mixtures was about 100%. Differences were noted between PM2.5 and PM1.

  14. Instrumental neutron activation analysis of coal and its combustion residues from a power plant

    International Nuclear Information System (INIS)

    Lim, J.M.; Jeong, J.H.; Lee, J.H.

    2013-01-01

    A growing demand of electrical energy derived from coal combustion led to a significant increase of coal ash as residues. Approximately 70 % of the fly ashes are recycled, while most of the bottom ashes have been land-filled in the ash pond in Korea. In this work, to evaluate the potential impacts of the residues from a coal power plant on the environment, its inorganic elemental components were determined by INAA and PGAA. Coal ash samples were collected from the biggest power plant complex in Korea. These samples were analyzed by using the NAA facilities in the HANARO research reactor of the Korea Atomic Energy Research Institute. A total of 31 elements were analyzed in the samples, and certified reference materials were used for the analytical quality control. The enrichment status of a given metal in fuel coal and ashes was investigated by its concentration ratio. In order to assess the impact of the coal combustion residues on ecosystem, their concentrations determined for each respective type of the samples were compared to both reference data and nearby beach sand samples. (author)

  15. Numerical investigation of influence thermal preparation coal on nitric oxides formation in combustion process

    Energy Technology Data Exchange (ETDEWEB)

    Chernetskaya, N. [Siberian Federal Univ., Krasnoyarsk (Russian Federation); Chernetsky, M.; Dekterev, A. [Siberian Federal Univ., Krasnoyarsk (Russian Federation); Kutateladze Institute of Thermophysics, Novosibirsk (Russian Federation)

    2013-07-01

    Emissions of nitrogen oxides from coal combustion are a major environmental problem because they have been shown to contribute to the formation of acid rain and photochemical smog. Coal thermalpreparation before furnace delivery is effective method to reduce NOx emissions, shown by experiments in small-scale facilities (Babiy VI, Alaverdov PI, Influence of thermal preparation pulverized coal on nitric oxides outlet for combustion different metamorphized coal. ATI, 1983). This paper presents the mathematical model of burning thermal preparation coal. Validation of the model was carried out on laboratory-scale plant of All-Russia thermal engineering institute. Modeling of low-emissive burner with preliminary heating coal dust is made for the purpose of search of burner optimal constructions which provides low concentration of nitric oxides in the boiler. For modeling are used in-house CFD code ''{sigma}Flow'' (Dekterev AA, Gavrilov AA, Harlamov EB, Litvintcev KY, J Comput Technol 8(Part 1):250-255, 2003).

  16. Chemical-Looping Combustion and Gasification of Coals and Oxygen Carrier Development: A Brief Review

    Directory of Open Access Journals (Sweden)

    Ping Wang

    2015-09-01

    Full Text Available Chemical-looping technology is one of the promising CO2 capture technologies. It generates a CO2 enriched flue gas, which will greatly benefit CO2 capture, utilization or sequestration. Both chemical-looping combustion (CLC and chemical-looping gasification (CLG have the potential to be used to generate power, chemicals, and liquid fuels. Chemical-looping is an oxygen transporting process using oxygen carriers. Recently, attention has focused on solid fuels such as coal. Coal chemical-looping reactions are more complicated than gaseous fuels due to coal properties (like mineral matter and the complex reaction pathways involving solid fuels. The mineral matter/ash and sulfur in coal may affect the activity of oxygen carriers. Oxygen carriers are the key issue in chemical-looping processes. Thermogravimetric analysis (TGA has been widely used for the development of oxygen carriers (e.g., oxide reactivity. Two proposed processes for the CLC of solid fuels are in-situ Gasification Chemical-Looping Combustion (iG-CLC and Chemical-Looping with Oxygen Uncoupling (CLOU. The objectives of this review are to discuss various chemical-looping processes with coal, summarize TGA applications in oxygen carrier development, and outline the major challenges associated with coal chemical-looping in iG-CLC and CLOU.

  17. Waste generation comparison: Coal-fired versus nuclear power plants

    International Nuclear Information System (INIS)

    LaGuardia, T.S.

    1998-01-01

    Low-level radioactive waste generation and disposal attract a great deal of attention whenever the nuclear industry is scrutinized by concerned parties, be it the media, the public, or political interests. It is therefore important to the nuclear industry that this issue be put into perspective relative to other current forms of energy production. Most of the country's fossil-fueled power comes from coal-fired plants, with oil and gas as other fuel sources. Most of the generated waste also comes from coal plants. This paper, therefore, compares waste quantities generated by a typical (1150-MW(electric)) pressurized water reactor (PWR) to that of a comparably sized coal-fired power plant

  18. 226Ra adsorption on active coals from waste waters

    International Nuclear Information System (INIS)

    Panturu, E.; Georgescu, D.P.; Serban, N.; Filip, D.; Radulescu, R.

    2000-01-01

    During the mining and extraction of uranium, the principle means of protection measurement is to prevent uranium and its products diffusing into the environment. The main carriers of radioactive elements in the environment are air and water. Therefore, reduction of the pollution at a uranium mine can be achieved by the treatment of waste waters contaminated with 226 Ra Radium contaminated waste waters represent a major biological risk. This paper presents the results of the study of the sorption of 226 Ra on active coal mechanisme and the influence of the physical and chemical characteristics of fluid. The 226 Ra removal from the residue pond water at the uranium ore processing plant was studied using eight types of indigenous active coals. The experimental results for each type of active coal and their effect on removal of 226 Ra from waste waters are presented in this paper. (author)

  19. 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.

  20. Steam generation by combustion of processed waste fats

    Energy Technology Data Exchange (ETDEWEB)

    Pudel, F.; Lengenfeld, P. [OEHMI Forschung und Ingenieurtechnik GmbH, Magdeburg (Germany)

    1993-12-31

    The use of specially processed waste fats as a fuel oil substitute offers, at attractive costs, an environmentally friendly alternative to conventional disposal like refuse incineration or deposition. For that purpose the processed fat is mixed with EL fuel oil and burned in a standard steam generation plant equipped with special accessories. The measured emission values of the combustion processes are very low.

  1. Qualitative analysis of coal combusted in boilers of the thermal power plants in Bosnia and Herzegovina

    Directory of Open Access Journals (Sweden)

    Đurić Slavko N.

    2012-01-01

    Full Text Available In this paper we have looked into the qualitative analysis of coals in Bosnia and Herzegovina (B-H. The analysis includes the following characteristics: moisture (W, ash (A, combustible matter (Vg and lower heating value (Hd. From the statistic parameters we have determined: absolute range (R, arithmetic mean (X, standard deviation (S and variations coefficient (Cv. It has been shown that the coal characteristics (W, A, Vg, Hd have normal distribution. The analysis show that there are considerable deviations of ash characteristics: moisture (36.23%, ash (34.21%, combustible matter (16.15% and lower heating value (25.16% from the mean value which is shown by the variations coefficient (Cv. Large oscilations of mass portions: W, A, Vg and Hd around the mean value can adversely influence the function of a boiler plant and an electric filter plant in thermal power plants in B-H in which the mentioned types of coal burn. Large ash oscilations (34.21% around the mean value point out to the inability of application of dry procedures of desulphurisation of smoke gasses (FGD due to the additional quantity of ash. It has been shown that the characteristics of Bosnian types of coal do not deviate a lot from the characteristics of coal in the surrounding countries (coals of Serbia and Monte Negro. The results can be used in analysis of coal combustion in thermal power plants, optimisation of electrical-filtre, reduction of SO2 in smoke gas and other practical problems.

  2. Interactions of coal gangue and pine sawdust during combustion of their blends studied using differential thermogravimetric analysis.

    Science.gov (United States)

    Zhang, Yuanyuan; Zhang, Zhezi; Zhu, Mingming; Cheng, Fangqin; Zhang, Dongke

    2016-08-01

    The interactions between coal gangue and pine sawdust during the combustion process were studied using thermogravimetric analysis. The effect of the blending ratio, oxygen concentration and heating rate on the weight loss (TG) and differential thermogravimetric (TGA) profiles was examined. The TG and DTG curves of the blends were not additives of those of the individual materials, suggesting that interactions between coal gangue and pine sawdust had occurred during the combustion, especially in the temperature range of 400-600°C. Kinetic analysis confirmed that the combustion of coal gangue, pine sawdust and their blends was chemical reaction controlled. Further analysis revealed that the interactions between coal gangue and pine sawdust were primarily due to thermal effects rather than structural changes, with the thermal inertia of coal gangue dominating over the behaviour of the blends. The interactions decreased with decreasing the coal gangue ratio in the blend, oxygen concentration and heating rate. Copyright © 2016 Elsevier Ltd. All rights reserved.

  3. Early detection of spontaneous combustion of coal in underground coal mines with development of an ethylene enriching system

    Energy Technology Data Exchange (ETDEWEB)

    Xie, Jun; Xue, Sheng [CSIRO Earth Science and Resource Engineering, Kenmore (Australia); Cheng, Weimin; Wang, Gang [Shandong University of Science and Technology, Qingdao (China)

    2011-01-01

    Spontaneous combustion of coal (sponcom) is a major hazard in underground coal mining operations. If not detected early and managed properly, it can seriously affect mine safety and productivity. Gaseous products of sponcom, such as carbon monoxide, ethylene and hydrogen, are commonly used in coal mines as indicators to reflect the state of the sponcom. Studies have shown that ethylene starts to occur when sponcom reaches a characteristic temperature. However, due to dilution of ventilation air and detection limits of the instruments used for gas analysis at coal mines, ethylene cannot be detected until the sponcom has developed past its early stage, missing an optimum opportunity for mine operators to control the hazard. To address the issue, an ethylene-enriching system, based on its physical adsorption and desorption properties, has been developed to increase detection sensitivity of the ethylene concentration in mine air by about 10 times. This system has successfully been applied in a number of underground coal mines in China to detect sponcom at its early stage and enable mine operators to take effective control measures. This paper describes the ethylene enriching system and its application. (author)

  4. Use of artificial intelligence techniques for optimisation of co-combustion of coal with biomass

    Energy Technology Data Exchange (ETDEWEB)

    Tan, C.K.; Wilcox, S.J.; Ward, J. [University of Glamorgan, Pontypridd (United Kingdom). Division of Mechanical Engineering

    2006-03-15

    The optimisation of burner operation in conventional pulverised-coal-fired boilers for co-combustion applications represents a significant challenge This paper describes a strategic framework in which Artificial Intelligence (AI) techniques can be applied to solve such an optimisation problem. The effectiveness of the proposed system is demonstrated by a case study that simulates the co-combustion of coal with sewage sludge in a 500-kW pilot-scale combustion rig equipped with a swirl stabilised low-NOx burner. A series of Computational Fluid Dynamics (CFD) simulations were performed to generate data for different operating conditions, which were then used to train several Artificial Neural Networks (ANNs) to predict the co-combustion performance. Once trained, the ANNs were able to make estimations of unseen situations in a fraction of the time taken by the CFD simulation. Consequently, the networks were capable of representing the underlying physics of the CFD models and could be executed efficiently for a large number of iterations as required by optimisation techniques based on Evolutionary Algorithms (EAs). Four operating parameters of the burner, namely the swirl angles and flow rates of the secondary and tertiary combustion air were optimised with the objective of minimising the NOx and CO emissions as well as the unburned carbon at the furnace exit. The results suggest that ANNs combined with EAs provide a useful tool for optimising co-combustion processes.

  5. 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.

  6. Lab-scale investigation of Middle-Bosnia coals to achieve high-efficient and clean combustion technology

    Directory of Open Access Journals (Sweden)

    Smajevic Izet

    2014-01-01

    Full Text Available This paper describes full lab-scale investigation of Middle-Bosnia coals launched to support selection an appropriate combustion technology and to support optimization of the boiler design. Tested mix of Middle-Bosnia brown coals is projected coal for new co-generation power plant Kakanj Unit 8 (300-450 MWe, EP B&H electricity utility. The basic coal blend consisting of the coals Kakanj: Breza: Zenica at approximate mass ratio of 70:20:10 is low grade brown coal with very high percentage of ash - over 40%. Testing that coal in circulated fluidized bed combustion technique, performed at Ruhr-University Bohum and Doosan Lentjes GmbH, has shown its inconveniency for fluidized bed combustion technology, primarily due to the agglomeration problems. Tests of these coals in PFC (pulverized fuel combustion technology have been performed in referent laboratory at Faculty of Mechanical Engineering of Sarajevo University, on a lab-scale PFC furnace, to provide reliable data for further analysis. The PFC tests results are fitted well with previously obtained results of the burning similar Bosnian coal blends in the PFC dry bottom furnace technique. Combination of the coals shares, the process temperature and the air combustion distribution for the lowest NOx and SO2 emissions was found in this work, provided that combustion efficiency and CO emissions are within very strict criteria, considering specific settlement of lab-scale furnace. Sustainability assessment based on calculation economic and environmental indicators, in combination with Low Cost Planning method, is used for optimization the power plant design. The results of the full lab-scale investigation will help in selection optimal Boiler design, to achieve sustainable energy system with high-efficient and clean combustion technology applied for given coals.

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

    DEFF Research Database (Denmark)

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

    2013-01-01

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

  8. Fractionation of mercury stable isotopes during coal combustion and seawater flue gas desulfurization

    International Nuclear Information System (INIS)

    Huang, Shuyuan; Yuan, Dongxing; Lin, Haiying; Sun, Lumin; Lin, Shanshan

    2017-01-01

    In the current study, fractionation of mercury isotopes during coal combustion and seawater flue gas desulfurization (SFGD) in a coal-fired power plant using a SFGD system was investigated. Fourteen samples were collected from the power plant. The samples were pretreated with a combustion-trapping method and were analyzed with a multi-collector inductively coupled plasma mass spectrometer (MC-ICP-MS). Compared with the raw coal, the bottom ash was enriched with lighter mercury isotopes with δ 202 Hg values ranging from −0.45 to −0.03‰. The fly ash was enriched with lighter mercury isotopes with δ 202 Hg values ranging from −1.49 to −0.73‰ for Chinese coal and from −1.47 to −0.62‰ for Indonesian coal. The δ 202 Hg of fresh seawater and desulfurized seawater was found to be −1.32 and −0.32‰ respectively. These δ 202 Hg values indicated that the desulfurized seawater was enriched with heavier mercury isotopes. Based upon the calculated results obtained from the mass balance equation, it was suggested that the stack emissions were enriched with lighter mercury isotopes. Mass independent fractionation was observed in most of the samples with a Δ 199 Hg/Δ 201 Hg ratio of approximately 0.96. The results help in improving the understanding of mercury isotope fractionation during coal combustion and SFGD, and are also useful in tracing the mercury emissions from coal fired power plants. - Highlights: • Spread of 1.5‰ was observed in δ 202 Hg values of raw coals and coal related samples. • The δ 202 Hg values were more negative in fly ash than those in the raw coal. • The flue gas had a significant Hg fractionation after desulfurization. • The stack emissions were enriched with lighter isotopes compared with the raw coal.

  9. Effect of the Reburning Zone Stoichiometry on the Nox Concentration at the Three-Stage Combustion of Pulverized Coal

    Directory of Open Access Journals (Sweden)

    Chernetskaya Nelya

    2016-01-01

    Full Text Available Numerical study of heat and mass transfer taking into account the combustion of coal particles in the furnace at the three-stage combustion of pulverized coal was performed. Analysis of the reburning zone stoichiometry on the concentration of nitrogen oxides at the furnace outlet was made. The values of excess air in the primary and reburning combustion zones, providing for the concentration of nitrogen oxides at the furnace outlet is not more than 350 mg/m3 and unburned carbon not more than 1 % when burning coal with a high content of nitrogen were established.

  10. Computational fluid dynamics (CFD) analysis of the coal combustion in a boiler of a thermal power plant using different kinds of the manufactured coals

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Cristiano Vitorino da; Lazzari, Luis Carlos; Ziemniczak, Aline; Beskow, Arthur Bortolin [Universidade Regional Integrada do Alto Uruguai e das Missoes (URI), Erechim, RS (Brazil)], E-mails: cristiano@uricer.edu.br, arthur@uricer.edu.br

    2010-07-01

    The state of the art in computational fluid dynamics and the availability of commercial codes encourage numerical studies of combustion processes. In the present work the commercial software CFX Ansys Europe Ltd. has been used to study the combustion of pulverized coal into the boiler of a thermal power plant. The objective of this work is to obtain new information for process optimization. Different kinds of manufactured coals were numerically tested in a thermal power plant installed at the southeast region of Brazil. The simulations were made using the actual burning conditions of the boiler. Results include the residence time of the fuel into the combustion chamber, temperature fields, flow fluid mechanics, heat transfer and pollutant formation, as well as the CO and NOx concentrations, aiming to determinate the best conditions to burn the investigated coals. The numerical investigation of the phenomena involved on the coal combustion processes are used to complete the experimental information obtained in operational tests. Considering the characteristics of different kinds of manufactured coals used, with this study is possible to achieve the most efficient boiler operation parameters, with decreasing costs of electricity production and reduction of environmentally harmful emissions. It was verified that the different kinds of manufactured coals demand different operation conditions, and the kind of manufactured coal used on the combustion process has a significant effect on the pollutant formation, mainly in rel action with ash concentration. (author)

  11. [Quantitative spectrum analysis of characteristic gases of spontaneous combustion coal].

    Science.gov (United States)

    Liang, Yun-Tao; Tang, Xiao-Jun; Luo, Hai-Zhu; Sun, Yong

    2011-09-01

    Aimed at the characteristics of spontaneous combustion gas such as a variety of gases, lou limit of detection, and critical requirement of safety, Fourier transform infrared (FTIR) spectral analysis is presented to analyze characteristic gases of spontaneous combustion In this paper, analysis method is introduced at first by combing characteristics of absorption spectra of analyte and analysis requirement. Parameter setting method, sample preparation, feature variable abstract and analysis model building are taken into consideration. The methods of sample preparation, feature abstraction and analysis model are introduced in detail. And then, eleven kinds of gases were tested with Tensor 27 spectrometer. CH4, C2H6, C3H8, iC4H10, nC4H10, C2 H4, C3 H6, C3 H2, SF6, CO and CO2 were included. The optical path length was 10 cm while the spectra resolution was set as 1 cm(-1). The testing results show that the detection limit of all analytes is less than 2 x 10(-6). All the detection limits fit the measurement requirement of spontaneous combustion gas, which means that FTIR may be an ideal instrument and the analysis method used in this paper is competent for spontaneous combustion gas measurement on line.

  12. Potential health impacts of burning coal beds and waste banks

    Science.gov (United States)

    Finkelman, R.B.

    2004-01-01

    Uncontrolled release of pollutants from burning coal beds and waste banks presents potential environmental and human health hazards. On a global scale, the emissions of large volumes of greenhouse gases from burning coal beds may contribute to climate change that alters ecosystems and patterns of disease occurrence. On regional and local scales, the emissions from burning coal beds and waste banks of acidic gases, particulates, organic compounds, and trace elements can contribute to a range of respiratory and other human health problems. Although there are few published reports of health problems caused by these emissions, the potential for problems can be significant. In India, large numbers of people have been displaced from their homes because of health problems caused by emissions from burning coal beds. Volatile elements such as arsenic, fluorine, mercury, and selenium are commonly enriched in coal deposits. Burning coal beds can volatilize these elements, which then can be inhaled, or adsorbed on crops and foods, taken up by livestock or bioaccumulated in birds and fish. Some of these elements can condense on dust particles that can be inhaled or ingested. In addition, selenium, arsenic, lead, tin, bismuth, fluorine, and other elements condense where the hot gaseous emissions come in contact with ambient air, forming mats of concentrated efflorescent minerals on the surface of the ground. These mats can be leached by rainwater and washed into local water bodies providing other potential routes of exposure. Although there are little data linking burning coal beds and waste banks to known health problems, a possibly analogous situation exists in rural China where mineralized coal burned in a residential environment has caused widespread and severe health problems such as fluorosis and arseniasis. ?? 2004 Elsevier B.V. All rights reserved.

  13. Co-firing a pressurized fluidized-bed combustion system with coal and refuse derived fuels and/or sludges. Task 16

    Energy Technology Data Exchange (ETDEWEB)

    DeLallo, M.; Zaharchuk, R.

    1994-01-01

    The co-firing of waste materials with coal in utility scale power plants has emerged as an effective approach to produce energy and manage municipal waste. Leading this approach, the atmospheric fluidized-bed combustor (AFBC) has demonstrated its commercial acceptance in the utility market as a reliable source of power burning a variety of waste and alternative fuels. The fluidized bed, with its stability of combustion, reduces the amount of thermochemical transients and provides for easier process control. The application of pressurized fluidized-bed combustor (PFBC) technology, although relatively new, can provide significant enhancements to the efficient production of electricity while maintaining the waste management benefits of AFBC. A study was undertaken to investigate the technical and economic feasibility of co-firing a PFBC with coal and municipal and industrial wastes. Focus was placed on the production of electricity and the efficient disposal of wastes for application in central power station and distributed locations. Wastes considered for co-firing include municipal solid waste (MSW), tire-derived fuel (TDF), sewage sludge, and industrial de-inking sludge. Issues concerning waste material preparation and feed, PFBC operation, plant emissions, and regulations are addressed. This paper describes the results of this investigation, presents conclusions on the key issues, and provides recommendations for further evaluation.

  14. Transformations of inorganic coal constituents in combustion systems. Volume 1, sections 1--5: Final report

    Energy Technology Data Exchange (ETDEWEB)

    Helble, J.J. [ed.; Srinivasachar, S.; Wilemski, G.; Boni, A.A. [PSI Technology Co., Andover, MA (United States); Kang, Shin-Gyoo; Sarofim, A.F.; Graham, K.A.; Beer, J.M. [Massachusetts Inst. of Tech., Cambridge, MA (United States); Peterson, T.W.; Wendt, J.O.L.; Gallagher, N.B.; Bool, L. [Arizona Univ., Tucson, AZ (United States); Huggins, F.E.; Huffman, G.P.; Shah, N.; Shah, A. [Kentucky Univ., Lexington, KY (United States)

    1992-11-01

    The inorganic constituents or ash contained in pulverized coal significantly increase the environmental and economic costs of coal utilization. For example, ash particles produced during combustion may deposit on heat transfer surfaces, decreasing heat transfer rates and increasing maintenance costs. The minimization of particulate emissions often requires the installation of cleanup devices such as electrostatic precipitators, also adding to the expense of coal utilization. Despite these costly problems, a comprehensive assessment of the ash formation and had never been attempted. At the start of this program, it was hypothesized that ash deposition and ash particle emissions both depended upon the size and chemical composition of individual ash particles. Questions such as: What determines the size of individual ash particles? What determines their composition? Whether or not particles deposit? How combustion conditions, including reactor size, affect these processes? remained to be answered. In this 6-year multidisciplinary study, these issues were addressed in detail. The ambitious overall goal was the development of a comprehensive model to predict the size and chemical composition distributions of ash produced during pulverized coal combustion. Results are described.

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

    Energy Technology Data Exchange (ETDEWEB)

    Hurt, R.H.

    1999-03-11

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

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

    Energy Technology Data Exchange (ETDEWEB)

    Hurt, R.H.

    1999-07-07

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

  17. Acid digestion of combustible wastes: a status report

    International Nuclear Information System (INIS)

    Lerch, R.E.

    1975-05-01

    Work at the Hanford Engineering Development Laboratory on development of the acid digestion process for treating combustible wastes is discussed. Materials such as paper, rubber, and plastics are readily decomposed into a low volume, noncombustible residue. Engineering results using the Acid Digestion Test Unit are discussed. Tests to date generally duplicated earlier laboratory results with respect to waste processing rates, volume reduction, off-gas generation rates and volumes, acid consumption, and completeness of reaction. Demonstrated processing rates were as high as 5 kg/hr for short duration run periods. The tests indicated engineering feasibility of the acid digestion process and showed acid digestion to be a potentially attractive method for treating combustible nuclear wastes. Other areas discussed in the report are behavior of plutonium and americium during acid digestion, behavior of various construction materials, and safety. An integrated flowsheet for operation of an acid digestion unit is also presented. (U.S.)

  18. Measurement of O2 in the Combustion Chamber of Apulverized Coal Boiler

    Directory of Open Access Journals (Sweden)

    Břetislav Janeba

    2012-01-01

    Full Text Available Operational measurements of the O2 concentration in the combustion chamber of a pulverized coal boiler are not yet common practice. Operators are generally satisfied with measuring the O2 concentration in the second pass of the boiler, usually behind the economizer, where a flue gas sample is extracted for analysis in a classical analyzer. A disadvantage of this approach is that there is a very weak relation between the measured value and the condition in specific locations in the fireplace, e.g. the function of the individual burners and the combustion process as a whole. A new extractionline was developed for measuring the O2 concentration in the combustion chamber. A planar lambda probe is used in this approach. The extraction line is designed to get outputs that can be used directly for diagnosis or management of the combustion in the boiler.

  19. Acid digestion of combustible radioactive wastes

    International Nuclear Information System (INIS)

    Allen, C.R.; Lerch, R.E.; Crippen, M.D.; Cowan, R.G.

    1982-03-01

    The following conclusions resulted from operation of Radioactive Acid Digestion Test Unit (RADTU) for processing transuranic waste: (1) the acid digestion process can be safely and efficiently operated for radioactive waste treatment.; (2) in transuranic waste treatment, there was no detectable radionuclide carryover into the exhaust off-gas. The plutonium decontamination factor (DF) between the digester and the second off-gas tower was >1.5 x 10 6 and the overall DF from the digester to the off-gas stack was >1 x 10 8 ; (3) plutonium can be easily leached from undried digestion residue with dilute nitric acid (>99% recovery). Leachability is significantly reduced if the residue is dried (>450 0 stack temp.) prior to leaching; (4) sulfuric acid recovery and recycle in the process is 100%; (5) nitric acid recovery is typically 35% to 40%. Losses are due to the formation of free nitrogen (N 2 ) during digestion, reaction with chlorides in waste (NO 2 stack was > 1.5 x 10 6 andl), and other process losses; (6) noncombustible components comprised approximately 6% by volume of glovebox waste and contained 18% of the plutonium; (7) the acid digestion process can effectively handle a wide variety of waste forms. Some design changes are desirable in the head end to reduce manual labor, particularly if large quantities of specific waste forms will be processed; (8) with the exception of residue removal and drying equipment, all systems performed satisfactorily and only minor design and equipment changes would be recommended to improve performance; and(9) the RADTU program met all of its planned primary objectives and all but one of additional secondary objectives

  20. 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)

  1. Combustion of pulverized coal in counter-current flow

    Energy Technology Data Exchange (ETDEWEB)

    Timnat, Y M; Goldman, Y [Technion-Israel Inst. of Tech., Haifa (Israel). Faculty of Aerospace Engineering

    1991-01-01

    In this report we describe the results obtained with two prototypes of pulverized coal combustors operating in counter-current flow, one at atmospheric pressure, the other at higher pressure and compare them to the predictions of a theoretical-numerical model, we have developed. The first prototype treats a vertical configuration, eight times larger than the one treated before (Hazanov et al. 1985), while in the second a horizontal arrangement with a smaller volume is studied. Attention was focused on particle trajectories, burnout, angle of injection, ash separation by rotational motion, effects of initial particle size and temperature, impingement velocity and the effect of gravity. Main development activity was directed to achieving stable and reliable coal burning in the combustors.

  2. 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.

  3. Modeling and optimization of processes for clean and efficient pulverized coal combustion in utility boilers

    Directory of Open Access Journals (Sweden)

    Belošević Srđan V.

    2016-01-01

    Full Text Available Pulverized coal-fired power plants should provide higher efficiency of energy conversion, flexibility in terms of boiler loads and fuel characteristics and emission reduction of pollutants like nitrogen oxides. Modification of combustion process is a cost-effective technology for NOx control. For optimization of complex processes, such as turbulent reactive flow in coal-fired furnaces, mathematical modeling is regularly used. The NOx emission reduction by combustion modifications in the 350 MWe Kostolac B boiler furnace, tangentially fired by pulverized Serbian lignite, is investigated in the paper. Numerical experiments were done by an in-house developed three-dimensional differential comprehensive combustion code, with fuel- and thermal-NO formation/destruction reactions model. The code was developed to be easily used by engineering staff for process analysis in boiler units. A broad range of operating conditions was examined, such as fuel and preheated air distribution over the burners and tiers, operation mode of the burners, grinding fineness and quality of coal, boiler loads, cold air ingress, recirculation of flue gases, water-walls ash deposition and combined effect of different parameters. The predictions show that the NOx emission reduction of up to 30% can be achieved by a proper combustion organization in the case-study furnace, with the flame position control. Impact of combustion modifications on the boiler operation was evaluated by the boiler thermal calculations suggesting that the facility was to be controlled within narrow limits of operation parameters. Such a complex approach to pollutants control enables evaluating alternative solutions to achieve efficient and low emission operation of utility boiler units. [Projekat Ministarstva nauke Republike Srbije, br. TR-33018: Increase in energy and ecology efficiency of processes in pulverized coal-fired furnace and optimization of utility steam boiler air preheater by using in

  4. Towards a coherent European approach for taxation of combustible waste

    International Nuclear Information System (INIS)

    Dubois, Maarten

    2013-01-01

    Highlights: • Current European waste taxes do not constitute a level playing field. • Integrating waste incineration in EU ETS avoids regional tax competition. • A differentiated incineration tax is a second-best instrument for NO x emissions. • A tax on landfilled incineration residues stimulates ash treatment. - Abstract: Although intra-European trade of combustible waste has grown strongly in the last decade, incineration and landfill taxes remain disparate within Europe. The paper proposes a more coherent taxation approach for Europe that is based on the principle of Pigovian taxation, i.e. the internalization of environmental damage costs. The approach aims to create a level playing field between European regions while reinforcing incentives for sustainable management of combustible waste. Three important policy recommendations emerge. First, integrating waste incineration into the European Emissions Trading System for greenhouse gases (EU ETS) reduces the risk of tax competition between regions. Second, because taxation of every single air pollutant from waste incineration is cumbersome, a differentiated waste incineration tax based on NO x emissions can serve as a second-best instrument. Finally, in order to strengthen incentives for ash treatment, a landfill tax should apply for landfilled incineration residues. An example illustrates the coherence of the policy recommendations for incineration technologies with diverse environmental effects

  5. Towards a coherent European approach for taxation of combustible waste

    Energy Technology Data Exchange (ETDEWEB)

    Dubois, Maarten, E-mail: maarten.dubois@kuleuven.be

    2013-08-15

    Highlights: • Current European waste taxes do not constitute a level playing field. • Integrating waste incineration in EU ETS avoids regional tax competition. • A differentiated incineration tax is a second-best instrument for NO{sub x} emissions. • A tax on landfilled incineration residues stimulates ash treatment. - Abstract: Although intra-European trade of combustible waste has grown strongly in the last decade, incineration and landfill taxes remain disparate within Europe. The paper proposes a more coherent taxation approach for Europe that is based on the principle of Pigovian taxation, i.e. the internalization of environmental damage costs. The approach aims to create a level playing field between European regions while reinforcing incentives for sustainable management of combustible waste. Three important policy recommendations emerge. First, integrating waste incineration into the European Emissions Trading System for greenhouse gases (EU ETS) reduces the risk of tax competition between regions. Second, because taxation of every single air pollutant from waste incineration is cumbersome, a differentiated waste incineration tax based on NO{sub x} emissions can serve as a second-best instrument. Finally, in order to strengthen incentives for ash treatment, a landfill tax should apply for landfilled incineration residues. An example illustrates the coherence of the policy recommendations for incineration technologies with diverse environmental effects.

  6. Deposit Formation in a 150 MWe Utility PF-Boiler during Co-combustion of Coal and Straw

    DEFF Research Database (Denmark)

    Andersen, Karin Hedebo; Frandsen, Flemming; Hansen, P. F. B.

    2000-01-01

    A conventional pc-fired boiler at the Danish energy company I/S Midtkraft has been converted to coal-straw co-combustion, and a 2 year demonstration program was initiated in January 1996, addressing several aspects of coal-straw co-combustion. Deposition trials were performed as part of the demon......A conventional pc-fired boiler at the Danish energy company I/S Midtkraft has been converted to coal-straw co-combustion, and a 2 year demonstration program was initiated in January 1996, addressing several aspects of coal-straw co-combustion. Deposition trials were performed as part...... problematic deposits. Go-firing straw also caused a change in the structure of the upstream deposits. During coal combustion an ordered, "finger" structure of the larger particles with small particles between was observed, whereas during co-combustion a more random deposition of the larger particles among...... arise when burning other coals, particularly coals with a high S or alkali metal content or a low content of ash. The behavior of K, Ca, S, and Cl was evaluated by use of thermodynamic calculations. The thermodynamically stable species agree with the observed behavior in the experiments, i.e. formation...

  7. Assessment of mercury health risks to adults from coal combustion

    Energy Technology Data Exchange (ETDEWEB)

    Lipfert, F.W.; Moskowitz, P.D.; Fthenakis, V.M.; DePhillips, M.P.; Viren, J.; Saroff, L.

    1994-05-01

    The U.S. Environmental Protection Agency (EPA) is preparing, for the U.S. Congress, a report evaluating the need to regulate mercury (Hg) emissions from electric utilities. This study, to be completed in 1995, will have important health and economic implications. In support of these efforts, the U.S. Department of Energy, Office of Fossil Energy, sponsored a risk assessment project at Brookhaven National Laboratory (BNL) to evaluate methylmercury (MeHg) hazards independently. In the BNL study, health risks to adults resulting from Hg emissions from a hypothetical 1000 MW{sub e} coal-fired power plant were estimated using probabilistic risk assessment techniques. The approach draws on the extant knowledge in each of the important steps in the calculation chain from emissions to health effects. Estimated results at key points in the chain were compared with actual measurements to help validate the modeled estimates. Two cases were considered: the baseline case (no local impacts), and the impact case (maximum local power-plant impact). The BNL study showed that the effects of emissions of a single power plant may double the background exposures to MeHg resulting from consuming fish obtained from a localized area near the power plant. Many implicit and explicit sources of uncertainty exist in this analysis. Those that appear to be most in need of improvement include data on doses and responses for potentially sensitive subpopulations (e.g., fetal exposures). Rather than considering hypothetical situations, it would also be preferable to assess the risks associated with actual coal-fired power plants and the nearby sensitive water bodies and susceptible subpopulations. Finally, annual total Hg emissions from coal burning and from other anthropogenic sources are still uncertain; this makes it difficult to estimate the effects of U.S. coal burning on global Hg concentration levels, especially over the long term.

  8. The effects of pf grind quality on coal burnout in a 1 MW combustion test facility

    Energy Technology Data Exchange (ETDEWEB)

    Richelieu Barranco; Michael Colechin; Michael Cloke; Will Gibb; Edward Lester [University of Nottingham, Nottingham (United Kingdom). School of Chemical, Environmental and Mining Engineering, Nottingham Fuel and Energy Centre

    2006-05-15

    A study was carried out to determine the effect of pf particle size distribution on coal burnout propensity in a 1 MW pulverised fuel burner. The specific aim of the work was to assess the improvement in combustion performance achievable by retrofitting commercially available high performance static or dynamic classifiers to existing plants. Two coals were used and were selected as representative of extremes in fuel characteristics experienced by coal importing utilities in Europe. Each coal was fired in the unit at a range of grind sizes to determine the overall impact of a variable performance from a mill. The levels of unburnt carbon in the resultant flyashes for the two coals showed significantly different behaviour. For the higher volatile coal, the unburnt carbon was found to be insensitive to grind quality. However, the coarser grinds of the other coal produced significantly lower unburnt carbon than expected when compared with the finest grinds. Generally the results indicate that the installation of improved classification technology, leading to a finer product, will help to lower unburnt carbon levels. Nevertheless, further work will be necessary to establish the levels of diminishing returns for grind size, burnout performance and grind costs. 21 refs., 4 figs., 4 tabs.

  9. 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...

  10. Reclamation technology development for western Arkansas coal refuse waste materials

    International Nuclear Information System (INIS)

    King, J.R.; Veith, D.L.

    1994-01-01

    Coal mining has been an important industry in the Arkansas River Valley Major Land Resource Area (MLRA) of western Arkansas for more than 100 yr., most of it with little regard for environmental concerns. Almost 3,640 ha. of land affected by surface coal mines cover the seven-county area, with less than 1,200 ha. currently in various stages of operation or reclamation. Since only the active mining sites must now be reclaimed by law, the remaining 2,440 ha. of abandoned land remains at the mercy of natural forces. Little topsoil exists on these sites and the coal wastes are generally acidic with a pH in the 4.0-5.5 range. Revegetation attempts under these conditions generally require continued maintenance and retreatment until an acceptable cover is achieved. If and when an acceptable vegetative cover is established, the cost frequently approaches $7,400/ha. ($3,000/acre). In an effort to resolve these issues and provide some direction for stabilizing coal waste lands, the US Department of Agriculture through its Soil Conservation Service Plant Materials Center at Boonville, Arkansas, received a Congressional Pass through administered by the US Bureau of Mines, to support a 5-yr. revegetation study on the coal mine spoils of western Arkansas. This paper reports the results through the spring of 1994 on that portion of the study dealing with the establishment of blackberries as a cash crop on coal mine spoils

  11. Influence of process parameters on coal combustion performance. Review, experiments and engineering modeling

    Energy Technology Data Exchange (ETDEWEB)

    Lans, R.P. van der

    1997-04-01

    The objective of this study is to improve the understanding of nitrogen oxide formation and carbon burnout during the combustion of pulverized coal, and to contribute to addressing the potential of chemical engineering models for the prediction of furnace temperatures, NO emissions and the amount of carbon in ash. To this purpose, the effect of coal quality on NO and burnout has been investigated experimentally, a radiation heat balance has been developed based on a simple chemical engineering methodology, and a mixing study has been conducted in order to describe the near burner macro mixing in terms of a reactor configuration. The influence of coal type and process conditions on NO formation and carbon burnout has been investigated experimentally in a 400 MW{sub e} corner fired boiler with over fire air, a 350 MW{sub e} opposed fired boiler, and in a 160 kW{sub t} pilot scale test rig. Three different coals were fired in each of the furnaces as part of the activities in group 3 of the European Union JOULE 2 Extension project `Atmospheric Pressure Combustion of Pulverized Coal and Coal Based Blends for Power Generation`. On the pilot scale test both single stage and air staged tests were performed. A simple, one-dimensional combustion and radiation heat transfer model has been developed for the furnace of full scale boilers. The model has been applied to the two boilers mentioned above, and is validated against measured temperatures and carbon in ash concentrations. A mixing study has been performed in order to initiate an investigation of the potential of chemical engineering models to predict NO from pulverized fuel burners. (EG) 11 refs.

  12. Burnout behaviour of bituminous coals in air-staged combustion conditions

    Energy Technology Data Exchange (ETDEWEB)

    Kluger, F.; Spliethoff, H.; Hein, K.R.G. [University of Stuttgart, Stuttgart (Germany). Inst. of Process Engineering and Power Plant (IVD)

    2001-07-01

    In order to determine the influence on burnout by the combustion conditions and the coal preparation, three bituminous coals sold on the world market, from three different locations in Poland, South Africa, and Australia, were studied more closely. For this purpose, the coals were ground in two different particle size ranges, which, besides the influence of the combustion conditions, such a temperature, residence time, and stoichiometry, made it possible to also investigate the impact on burnout by the coal preparation. The experiments were carried out in an electrically heated entrained-flow reactor with a thermal input of 8.5 kW. The parameters for the experiments are wall temperature (1000-1350{degree}C), air ratio (0.6-1.15) and two particle sizes (70% {lt} 75 {mu}m, 90% {lt} 75 {mu}m). The results show that in general, for increasing temperatures, the burnout quality will improve. For the Australian Illawara coal, another outcome is increased NOx emissions. Lowering the air ratio in the reduction zone leads to less NOx emission but to increased unburnt matter in ash. For the smaller particle size fraction, the analysis of the different particle sizes shows an improvement of the burnout without a change in NOx emissions. 10 refs., 10 figs., 2 tabs.

  13. UTILIZATION OF LOW NOx COAL COMBUSTION BY-PRODUCTS

    Energy Technology Data Exchange (ETDEWEB)

    J.Y. Hwang; X. Huang; M.G. McKimpson; R.E. Tieder; A.M. Hein; J.M. Gillis; D.C. Popko; K.L. Paxton; Z. Li; X. Liu; X. Song; R.I. Kramer

    1998-12-01

    Low NO{sub x} combustion practices are critical for reducing NO{sub x} emissions from power plants. These low NO{sub x} combustion practices, however, generate high residual carbon contents in the fly ash produced. These high carbon contents threaten utilization of this combustion by-product. This research has successfully developed a separation technology to render fly ash into useful, quality-controlled materials. This technology offers great flexibility and has been shown to be applicable to all of the fly ashes tested (more than 10). The separated materials can be utilized in traditional fly ash applications, such as cement and concrete, as well as in nontraditional applications such as plastic fillers, metal matrix composites, refractories, and carbon adsorbents. Technologies to use beneficiated fly ash in these applications are being successfully developed. In the future, we will continue to refine the separation and utilization technologies to expand the utilization of fly ash. The disposal of more than 31 million tons of fly ash per year is an important environmental issue. With continued development, it will be possible to increase economic, energy and environmental benefits by re-directing more of this fly ash into useful materials.

  14. Emission of nanoparticles during combustion of waste biomass in fireplace

    Science.gov (United States)

    Drastichová, Vendula; Krpec, Kamil; Horák, Jiří; Hopan, František; Kubesa, Petr; Martiník, Lubomír; Koloničný, Jan; Ochodek, Tadeáš; Holubčík, Michal

    2014-08-01

    Contamination of air by solid particles is serious problem for human health and also environment. Small particles in nano-sizes are more dangerous than same weight of larger size. Negative effect namely of the solid particles depends on (i) number, (ii) specific surface area (iii) respirability and (iv) bonding of others substances (e.g. PAHs, As, Cd, Zn, Cu etc.) which are higher for smaller (nano-sizes) particles compared to larger one. For this reason mentioned above this contribution deals with measuring of amount, and distribution of nanoparticles produced form combustion of waste city biomass in small combustion unit with impactor DLPI.

  15. Treatment of Decommissioning Combustible Wastes with Incineration Technology

    Energy Technology Data Exchange (ETDEWEB)

    Min, B. Y. Min; Yang, D. S.; Yun, G. S.; Lee, K. W.; Moon, J. K. [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2015-05-15

    The aim of the paper is current status of management for the decommissioning radioactive combustible and metal waste in KAERI. In Korea, two decommissioning projects were carried out for nuclear research facilities (KRR-1 and KRR-2) and a uranium conversion plant (UCP). Through the two decommissioning projects, lots of decommissioning wastes were generated. Decommissioning waste can be divided into radioactive waste and releasable waste. The negative pressure of the incineration chamber remained constant within the specified range. Off-gas flow and temperature were maintained constant or within the desired range. The measures gases and particulate materials in the stack were considerably below the regulatory limits. The achieved average volume reduction ratio during facility operation is about 1/65.

  16. Characterization of Oxy-combustion Impacts in Existing Coal-fired Boilers

    Energy Technology Data Exchange (ETDEWEB)

    Adams, Bradley [Univ. of Utah, Salt Lake City, UT (United States); Davis, Kevin [Univ. of Utah, Salt Lake City, UT (United States); Senior, Constance [Univ. of Utah, Salt Lake City, UT (United States); Shim, Hong Shim [Univ. of Utah, Salt Lake City, UT (United States); Otten, Brydger Van [Univ. of Utah, Salt Lake City, UT (United States); Fry, Andrew [Univ. of Utah, Salt Lake City, UT (United States); Wendt, Jost [Univ. of Utah, Salt Lake City, UT (United States); Eddings, Eric [Univ. of Utah, Salt Lake City, UT (United States); Paschedag, Alan [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Shaddix, Christopher [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Cox, William [Brigham Young Univ., Provo, UT (United States); Tree, Dale [Brigham Young Univ., Provo, UT (United States)

    2013-09-30

    Reaction Engineering International (REI) managed a team of experts from University of Utah, Siemens Energy, Praxair, Vattenfall AB, Sandia National Laboratories, Brigham Young University (BYU) and Corrosion Management Ltd. to perform multi-scale experiments, coupled with mechanism development, process modeling and CFD modeling, for both applied and fundamental investigations. The primary objective of this program was to acquire data and develop tools to characterize and predict impacts of CO{sub 2} flue gas recycle and burner feed design on flame characteristics (burnout, NO{sub x}, SO{sub x}, mercury and fine particle emissions, heat transfer) and operational concerns (fouling, slagging and corrosion) inherent in the retrofit of existing coal-fired boilers for oxy-coal combustion. Experimental work was conducted at Sandia National Laboratories’ Entrained Flow Reactor, the University of Utah Industrial Combustion Research Facility, and Brigham Young University. Process modeling and computational fluid dynamics (CFD) modeling was performed at REI. Successful completion of the project objectives resulted in the following key deliverables: 1) Multi-scale test data from 0.1 kW bench-scale, 100 kW and 200 kW laboratory-scale, and 1 MW semi-industrial scale combustors that describe differences in flame characteristics, fouling, slagging and corrosion for coal combustion under air-firing and oxygen-firing conditions, including sensitivity to oxy-burner design and flue gas recycle composition. 2) Validated mechanisms developed from test data that describe fouling, slagging, waterwall corrosion, heat transfer, char burnout and sooting under coal oxy-combustion conditions. The mechanisms were presented in a form suitable for inclusion in CFD models or process models. 3) Principles to guide design of pilot-scale and full-scale coal oxy-firing systems and flue gas recycle configurations, such that boiler operational impacts from oxy-combustion retrofits are minimized. 4

  17. Combustion of animal or vegetable based liquid waste products

    International Nuclear Information System (INIS)

    Wikman, Karin; Berg, Magnus

    2002-04-01

    In this project experiences from combustion of animal and vegetable based liquid waste products have been compiled. Legal aspects have also been taken into consideration and the potential for this type of fuel on the Swedish energy market has been evaluated. Today the supply of animal and vegetable based liquid waste products for energy production in Sweden is limited. The total production of animal based liquid fat is about 10,000 tonnes annually. The animal based liquid waste products origin mainly from the manufacturing of meat and bone meal. Since meat and bone meal has been banned from use in animal feeds it is possible that the amount of animal based liquid fat will decrease. The vegetable based liquid waste products that are produced in the processing of vegetable fats are today used mainly for internal energy production. This result in limited availability on the commercial market. The potential for import of animal and vegetable based liquid waste products is estimated to be relatively large since the production of this type of waste products is larger in many other countries compared to Sweden. Vegetable oils that are used as food or raw material in industries could also be imported for combustion, but this is not reasonable today since the energy prices are relatively low. Restrictions allow import of SRM exclusively from Denmark. This is today the only limit for increased imports of animal based liquid fat. The restrictions for handle and combustion of animal and vegetable based liquid waste products are partly unclear since this is covered in several regulations that are not easy to interpret. The new directive for combustion of waste (2000/76/EG) is valid for animal based waste products but not for cadaver or vegetable based waste products from provisions industries. This study has shown that more than 27,400 tonnes of animal based liquid waste products and about 6,000 tonnes of vegetable based liquid waste products were used for combustion in Sweden

  18. Cooperative Research Program in Coal-Waste Liquefaction

    Energy Technology Data Exchange (ETDEWEB)

    Gerald Huffman

    2000-03-31

    The results of a feasibility study for a demonstration plant for the liquefaction of waste plastic and tires and the coprocessing of these waste polymers with coal are presented. The study was conducted by a committee that included nine representatives from the CFFS, six from the U.S. Department of Energy - Federal Energy Technology Center (FETC), and four from Burns and Roe, Inc. The study included: (1) An assessment of current recycling practices, particularly feedstock recycling in Germany; (2) A review of pertinent research, and a survey of feedstock availability for various types of waste polymers; and (3) A conceptual design for a demonstration plant was developed and an economic analysis for various feedstock mixes. The base case for feedstock scenarios was chosen to be 200 tons per day of waste plastic and 100 tons per day of waste tires. For this base case with oil priced at $20 per barrel, the return on investment (ROI) was found to range from 9% to 20%, using tipping fees for waste plastic and tires typical of those existing in the U.S. The most profitable feedstock appeared to waste plastic alone, with a plant processing 300 t/d of plastic yielding ROI's from 13 to 27 %, depending on the tipping fees for waste plastic. Feedstock recycling of tires was highly dependent on the price that could be obtained for recovered carbon. Addition of even relatively small amounts (20 t/d) of coal to waste plastic and/or coal feeds lowered the ROI's substantially. It should also be noted that increasing the size of the plant significantly improved all ROI's. For example, increasing plant size from 300 t/d to1200 t/d approximately doubles the estimated ROI's for a waste plastic feedstock.

  19. Possibility of obtaining hydrogen from coal/waste-tyre mixture

    Czech Academy of Sciences Publication Activity Database

    Kříž, Vlastimil; Brožová, Zuzana; Přibyl, Oldřich; Sýkorová, Ivana

    2008-01-01

    Roč. 89, č. 11 (2008), s. 1069-1075 ISSN 0378-3820 R&D Projects: GA ČR(CZ) GA105/07/1407 Institutional research plan: CEZ:AV0Z30460519 Keywords : hydrogen * coal * waste tyres Subject RIV: DD - Geochemistry Impact factor: 2.066, year: 2008 www.elsevier.com/locate/fuproc/

  20. Tannery and coal mining waste disposal on soil

    Energy Technology Data Exchange (ETDEWEB)

    Kray, C.H.; Tedesco, M.J.; Bissani, C.A.; Gianello, C.; da Silva, K.J. [CEFET BG, Goncalves (Brazil)

    2008-11-15

    Tannery residues and coal mine waste are heavily polluting sources in Brazil, mainly in the Southern States of Rio Grande do Sul and Santa Catarina. In order to study the effects of residues of chrome leather tanning (sludge and leather shavings) and coal waste on soybean and maize crops, a field experiment is in progress since 1996, at the Federal University of Rio Grande do Sul Experimental Station, county of Eldorado do Sul, Brazil. The residues were applied twice (growing seasons 1996/97 and 1999/00). The amounts of tannery residues were applied according to their neutralizing value, at rates of up to 86.8 t ha{sup -1}, supplying from 671 to 1.342 kg ha{sup -1} Cr(III); coal waste was applied at a total rate of 164 t ha{sup -1}. Crop yield and dry matter production were evaluated, as well as the nutrients (N, P, K, Ca, Mg, Cu and Zn) and Cr contents. Crop yields with tannery sludge application were similar to those obtained with N and lime supplied with mineral amendments. Plant Cr absorption did not increase significantly with the residue application. Tannery sludge can be used also to neutralize the high acidity developed in the soil by coal mine waste.

  1. 30 CFR 816.84 - Coal mine waste: Impounding structures.

    Science.gov (United States)

    2010-07-01

    ... control, the probable maximum precipitation of a 6-hour precipitation event, or greater event as specified.... Runoff from areas above the disposal facility or runoff from surface of the facility that may cause...-hour design precipitation event. (e) Impounding structures constructed of or impounding coal mine waste...

  2. Emission of pollutants from coal combustion in Republic of Macedonia

    International Nuclear Information System (INIS)

    Popovski, Kiril; Armenski, Slave; Dimitrova, Jasminka

    1997-01-01

    It is shown the energy consumption picture of the Republic of Macedonia. It is determined the ratio of different kind of primary energy in meeting the needs of the state. It is used a common method for determination of air pollution during coal incineration. The results of this investigation should be analysed additionally, to ensure receiving of relevant conclusions for further activities in the field of environmental protection. There are given suggestions and means for instant activities, without financial support Tere are not analysed means and methods for environmental protections which are connected with big financial investments. (Author)

  3. 40 CFR 60.1025 - Do subpart E new source performance standards also apply to my municipal waste combustion unit?

    Science.gov (United States)

    2010-07-01

    ... standards also apply to my municipal waste combustion unit? 60.1025 Section 60.1025 Protection of... NEW STATIONARY SOURCES Standards of Performance for Small Municipal Waste Combustion Units for Which... municipal waste combustion unit? If this subpart AAAA applies to your municipal waste combustion unit, then...

  4. 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.

  5. Dew point of combustion products of coal from the Berezovo deposit

    Energy Technology Data Exchange (ETDEWEB)

    Petrov, V.A. (UralVTI (USSR))

    1990-11-01

    Evaluates properties of brown coal from the Berezovo deposit, Kansk-Achinsk basin, and properties of its combustion products. Coal properties are the following: sulfur content from 0.26 to 0.49%, ash content from 3.49 to 6.58%, moisture content from 31.6 to 36.9%, calorific value from 14,200 to 15,840 kJ/kg. Dew point of the combustion products amounts to 51 C and is equal to that of water vapor present in flue gases. Changing boiler output does not influence dew point. Increase in the excess air coefficient from 1.2 to 1.4 results in an increase in dew point by 2-3 K; further increase in air excess coefficient to 1.64 causes a decline in dew point by 3-4 K. 2 refs.

  6. Investigation of combustion of coal briquettes in a fluidized bed reactor

    Energy Technology Data Exchange (ETDEWEB)

    Boavida, Dulce; Abelha, Pedro; Gulyurtlu, Ibrahim; Cabrita, Isabel

    1999-07-01

    This paper discusses the results obtained from an experimental combustion work undertaken to investigate the behaviour of multicomponent briquettes, prepared by mixing two different particle sizes of coal and two different types of binder species. single briquettes were burned over a wide range of temperatures in a laboratory scale fluidised bed combustor facility. Nitrogen (NO{sub x}, and N{sub 2}O) and Sulphur (SO{sub 2}) oxides emissions resulting from the combustion of these briquettes were constantly monitored during the time of burning. The levels of O{sub 2}, CO{sub 2} and CO were also recorded during the same period. Experimental results showed that coal particle size influenced burn-out times and emissions levels of some of gaseous species. The hinder type was also found to have a major influence on the emissions of different pollutants.The temperature was observed to significantly influence the extent of the effects of the other operating parameters studied.

  7. Combustion of producer gas from gasification of south Sumatera lignite coal using CFD simulation

    Directory of Open Access Journals (Sweden)

    Vidian Fajri

    2017-01-01

    Full Text Available The production of gasses from lignite coal gasification is one of alternative fuel for the boiler or gas turbine. The prediction of temperature distribution inside the burner is important for the application and optimization of the producer gas. This research aims to provide the information about the influence of excess air on the temperature distribution and combustion product in the non-premixed burner. The process was carried out using producer gas from lignite coal gasification of BA 59 was produced by the updraft gasifier which is located on Energy Conversion Laboratory Mechanical Engineering Department Universitas Sriwijaya. The excess air used in the combustion process were respectively 10%, 30% and 50%. CFD Simulations was performed in this work using two-dimensional model of the burner. The result of the simulation showed an increase of excess air, a reduction in the gas burner temperature and the composition of gas (carbon dioxide, nitric oxide and water vapor.

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

    DEFF Research Database (Denmark)

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

    2014-01-01

    The yields of NO from combustion of bituminous coal, lignite, and biomass chars were investigated in O2/N2 and O2/CO 2 atmospheres. The experiments were performed in a laboratory-scale fixed-bed reactor in the temperature range of 850-1150 °C. To minimize thermal deactivation during char preparat......The yields of NO from combustion of bituminous coal, lignite, and biomass chars were investigated in O2/N2 and O2/CO 2 atmospheres. The experiments were performed in a laboratory-scale fixed-bed reactor in the temperature range of 850-1150 °C. To minimize thermal deactivation during char...

  9. Mercury emission monitoring on municipal waste combustion

    International Nuclear Information System (INIS)

    Braun, H.; Gerig, A.

    1991-01-01

    In waste incineration, mercury is the only heavy metal to be released as a gas, mostly as mercury(II) chloride, because of its high volatility. Continuous emission monitoring is possible only when mercury occurs in its elemental form. This paper reports on various possibilities of converting Hg(II) into Hg(0) that has been studied and tested on a laboratory scale and in the TAMARA refuse incineration pilot facility. Continuous mercury emission measurement appears to be possible, provided mercury is converted in the flue gas condensate precipitated. The measuring results obtained on two municipal solid waste and on one sewage treatment sludge incineration plants show that the mercury monitor is a highly sensitive and selective continuously working instrument for mercury emission monitoring

  10. Analytical methods relating to mineral matter in coal and ash from coal combustion

    Energy Technology Data Exchange (ETDEWEB)

    Creelman, R.A. [Ultra-Systems Technology Pty. Ltd., Indooroopilly, Qld. (Australia)

    2002-07-01

    The paper begins by describing the minerals that occur in coal, as well as trace elements. The testing methods that are then described include those that are in the main the standard tools for the examination and assessment of minerals in coal and ash. The techniques discussed include optical and beam techniques, X-ray methods and a variety of other useful methods. 12 refs.

  11. Combustion of palm oil solid waste in fluidized bed combustor

    International Nuclear Information System (INIS)

    Abdullah, I.; Shamsuddin, A.H.; Sopian, K.

    2000-01-01

    Results of experimental investigations of fluidized bed combustion of palm oil wastes consisting of shell, fibre and empty fruit bunches high heating value of 17450 kJ/kg and low heating value of 14500 kJ/kg. The fluidized bed combuster used has a vessel size of 486 x 10 6 mm 3 , surface area of evaporation tubes and distribution air pipes of 500 mm 2 and 320 mm 2 respectively. It was found that a fuel feeding rate 160 kg/h is required to achieve a steam flow rate of 600 kg/h, with the combustion efficiency 96% and boiler efficiency of 72%, emission level of flue gas NO x at less than 180 ppm, SO 2 at less than 20 ppm are measured in the flue gas. (Author)

  12. Pressurized fluidized bed combustion combined cycle power plant with coal gasification: Second generation pilot plant

    International Nuclear Information System (INIS)

    Farina, G.L.; Bressan, L.

    1991-01-01

    This paper presents the technical and economical background of a research and development program of a novel power generation scheme, which is based on coal gasification, pressurized fluid bed combustion and combined cycles. The participants in this program are: Foster Wheeler (project leader), Westinghouse, IGT and the USA Dept. of Energy. The paper describes the characteristics of the plant, the research program in course of implementation, the components of the pilot plant and the first results obtained

  13. Effect of oxy-fuel combustion with steam addition on coal ignition and burnout in an entrained flow reactor

    International Nuclear Information System (INIS)

    Riaza, J.; Alvarez, L.; Gil, M.V.; Pevida, C.; Pis, J.J.; Rubiera, F.

    2011-01-01

    The ignition temperature and burnout of a semi-anthracite and a high-volatile bituminous coal were studied under oxy-fuel combustion conditions in an entrained flow reactor (EFR). The results obtained under oxy-fuel atmospheres (21%O 2 -79%CO 2 , 30%O 2 -70% O 2 and 35%O 2 -65%CO 2 ) were compared with those attained in air. The replacement of CO 2 by 5, 10 and 20% of steam in the oxy-fuel combustion atmospheres was also evaluated in order to study the wet recirculation of flue gas. For the 21%O 2 -79%CO 2 atmosphere, the results indicated that the ignition temperature was higher and the coal burnout was lower than in air. However, when the O 2 concentration was increased to 30 and 35% in the oxy-fuel combustion atmosphere, the ignition temperature was lower and coal burnout was improved in comparison with air conditions. On the other hand, an increase in ignition temperature and a worsening of the coal burnout was observed when steam was added to the oxy-fuel combustion atmospheres though no relevant differences between the different steam concentrations were detected. -- Highlights: → The ignition temperature and the burnout of two thermal coals under oxy-fuel combustion conditions were determined. → The effect of the wet recirculation of flue gas on combustion behaviour was evaluated. → Addition of steam caused a worsening of the ignition temperature and coal burnout.

  14. Combustion of cork waste in a circulating fluidized bed combustor

    Energy Technology Data Exchange (ETDEWEB)

    Gulyurtlu, I.; Boavida, D.; Miranda, M.; Cabrita, I. [Dept. de Tecnologias de Combustao, ITE-INETI, Lisboa (Portugal); Abelha, P. [Coaltec e Ambiente, Lisboa (Portugal)

    1999-07-01

    There is currently an ongoing joint project between Portugal and Spain, which is being funded by the FAIR programme. The principal objective of the FAIR project is to investigate the application of the fluidised bed combustion (FBC) technology to burn cork wastes with the aim of overcoming the difficulties currently experienced in the cork processing industries. The combustion studies at INETI were carried out using the 300 kW{sub th} circulating fluidised bed facility. The combustor is square in cross section with each side being 0.3 m long. The combustor height is 5 m. The temperatures in the bed, the riser and that of the flue gases leaving the reactor were continuously monitored. The combustion gases leaving the reactor passed through the recycling cyclone first to capture most of particulates elutriated out of the combustor. The solid particles were intermittently collected for analysis to determine the amount of carbon present, which helped the combustion efficiency to be calculated. Instantaneous measurements of O{sub 2}, CO, CO{sub 2}, NO{sub x}, N{sub 2}O and SO{sub 2} present levels in the flue gases were also carried out. The combustion tests were done with both the cork waste dust and granular virgin cork. The difference is that cork dust gets contaminated during the process due to the use of various additives. Most of the combustion took place in the riser where the temperature was at times up to 523 K above that of the bed. The unburned carbon level was low ranging from about 1.5 to 2.% suggesting that most of the particles burned to completion in the riser. (orig.)

  15. Effect of reaction temperature on the PM10 features during coal combustion

    International Nuclear Information System (INIS)

    Sui, J.C.; Du, Y.G.; Liu, Q.C.

    2008-01-01

    Coal-fired power plants produce fine fly ash consisting of particulate matter (PM). Particulate matter less than 10 micrometers in aerodynamic diameter (PM 1 0) is of significant concern because of its adverse environmental and health impacts. This paper studied the effect of reaction temperature on particulate matter (PM 1 0) emission and its chemical composition. The emission characteristics and elemental partition of PM 1 0 from coal combustion were investigated in a drop tube furnace. The paper discussed the experimental apparatus and conditions as well as the coal properties and sample analysis. Liupanshui (LPS) bituminous coal from China was used for the study. The fuel composition of LPS coal and the composition of low temperature ash of Chinese LPS coal were described. The paper also presented the results of the study with reference to particle size distribution and emission characteristic of PM 1 0; elemental partition within PM 1 0; and effect of the reaction temperature on elemental partition within PM 1 0. The PM mass size distribution was found to be bimodal. 14 refs., 2 tabs., 6 figs

  16. Trace elements in coal ash

    Science.gov (United States)

    Deonarine, Amrika; Kolker, Allan; Doughten, Michael W.

    2015-01-01

    Coal ash is a residual waste product primarily produced by coal combustion for electric power generation. Coal ash includes fly ash, bottom ash, and flue-gas desulfurization products (at powerplants equipped with flue-gas desulfurization systems). Fly ash, the most common form of coal ash, is used in a range of products, especially construction materials. A new Environmental Protection Agency ruling upholds designation of coal ash as a non-hazardous waste under Subtitle D of the Resource Conservation and Recovery Act, allowing for the continued beneficial use of coal ash and also designating procedures and requirements for its storage.

  17. Drying wood waste with a pulse combustion dryer

    Energy Technology Data Exchange (ETDEWEB)

    Buchkowski, A.G. [Spectrum Engineering Corp., Ltd., Peterborough, Ontario (Canada); Kitchen, J.A. [John A. Kitchen, Ltd., Hastings, Ontario (Canada)

    1993-12-31

    There is a vast amount of wood waste available to be used as an alternate fuel if its moisture could be reduced efficiently. Tests have been conducted to assess an industrial dryer using pulse combustion as a heating source for drying wood waste; specifically sawdust and pulverized wet hog fuel. Pulse combustion offers the advantage of high heat transfer, efficient combustion, and low NO{sub x} emissions. The material is injected into the exhaust gases in the tailpipe of the combustor which uses natural gas or propane as a fuel. The turbulence created by the pulsations enhance the drying process by reducing the boundary layer thicknesses. The materials is further dried in a rotary drum. The material has been dried without scorching or burning in tests where the inlet moisture content has been as high as 60% on a wet basis. The outlet moisture contents achieved have typically been 10%. Analysis of the test data and cost estimates of the equipment indicate that the pulse combustion drying system is at least comparable to existing systems in terms of operating costs, and offers very significant savings in capital costs. Testing with various other materials such as wood pulp, sludges and peat is continuing to further assess the equipment`s performance.

  18. 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.

  19. Characteristic Study of Shenmu Bituminous Coal Combustion with Online TG-MS-FTIR

    Science.gov (United States)

    Pan, Guanfu

    2018-01-01

    The combustion characteristics of Shenmu bituminous pulverized coal (SBC) were comprehensively investigated with a combined TG-MS-FTIR system by considering the effect of particle size, heating rate and total flowrate. The combustion products were accurately quantified by normalization and numerical analysis of MS results. The results indicate that the decrease of the particle size, heating rate and total flowrate result in lower ignition and burnout temperatures. The activation energy tends to be lower with smaller particle size, lower heating rate and total flowrate. The MS and FTIR results demonstrate that lower concentrations of different products, such as NO, NO2, HCN, CH4 and SO2 were produced with smaller particle size, slower heating rate and lower total flowrate. The decrease of particle size would lead to more contact area with oxygen and slower heating rate could provide more sufficient time for the diffusion. High total flowrate would reduce the oxygen adsorbability on the coal particle surface and shorten the residence time of oxygen, which makes the ignition difficult to occur. This work will guide to understand the combustion kinetics of pulverized coals and be beneficial to control the formation of pollutants.

  20. Combustion properties, water absorption and grindability of raw/torrefied biomass pellets and Silantek coal

    Science.gov (United States)

    Matali, Sharmeela; Rahman, Norazah Abdul; Idris, Siti Shawaliah; Yaacob, Nurhafizah

    2017-12-01

    Torrefaction, also known as mild pyrolysis, is proven to convert raw biomass into a value-added energy commodity particularly for application in combustion and co-firing systems with improved storage and handling properties. This paper aims to compare the characteristics of Malaysian bituminous coal i.e. Silantek coal with raw and torrefied biomass pellet originated from oil palm frond and fast growing tree species, Leucaena Leucocephala. Biomass samples were initially torrefied at 300 °C for 60 minutes. Resulting torrefied biomass pellets were analysed using a number of standard fuel characterisation analyses i.e. elemental analysis, proximate analysis and calorific content (high heating values) experiments. Investigations on combustion characteristics via dynamic thermogravimetric analysis (TGA), grindability and moisture uptake tests were also performed on the torrefied biomass pellets. Better quality bio-chars were produced as compared to its raw forms and with optimal process conditions, torrefaction may potentially produces a solid fuel with combustion reactivity and porosity equivalent to raw biomass while having compatible energy density and grindability to coal.

  1. Reducing emission of nitrogen oxides during combustion of black coal from the Kuzbass

    Energy Technology Data Exchange (ETDEWEB)

    Kotler, V.R.; Lobov, G.V.; Gedike, I.A.

    1983-02-01

    Black coal from the Kuzbass used as fuel by the ZapSibTEhTs fossil-fuel power plant is rich in nitrogen: nitrogen content ranges from 2.8% to 3.5%. Under these conditions conventional methods of combustion cause air pollution exceeding permissible levels. A method for combustion of coal dust in stages has been successfully tested at the plant: some of the burners located in the top zone of the furnace (the BKZ-210-140F boiler) are used for air supply. From 16% to 18% of air supplied to the furnace is directed to the upper burners. Use of this system (called tertiary air supply as opposed to the secondary air system) reduced nitrogen oxide emission by 1.5 times (from 0.87 to 0.57 g/m/sup 3/). Position of nozzles used for tertiary air supply in relation to the burners used for supply of coal dust in the tangential shaped furnace is shown in a scheme. The optimum position of tertiary air supply system in relation to burners taking into account corrosion hazards as well as the hazards of reducing combustion efficiency is discussed. Recommendation on furnace design and burner position which prevent efficiency decrease and corrosion hazards are made.

  2. Immersion Freezing of Coal Combustion Ash Particles from the Texas Panhandle

    Science.gov (United States)

    Whiteside, C. L.; Tobo, Y.; Mulamba, O.; Brooks, S. D.; Mirrielees, J.; Hiranuma, N.

    2017-12-01

    Coal combustion aerosol particles contribute to the concentrations of ice-nucleating particles (INPs) in the atmosphere. Especially, immersion freezing can be considered as one of the most important mechanisms for INP formation in supercooled tropospheric clouds that exist at temperatures between 0°C and -38°C. The U.S. contains more than 550 operating coal-burning plants consuming 7.2 x 108 metric tons of coal (in 2016) to generate a total annual electricity of >2 billion MW-h, resulting in the emission of at least 4.9 x 105 metric tons of PM10 (particulate matter smaller than 10 µm in diameter). In Texas alone, 19 combustion plants generate 0.15 billion MW-h electricity and >2.4 x 104 metric tons of PM10. Here we present the immersion freezing behavior of combustion fly ash and bottom ash particles collected in the Texas Panhandle region. Two types of particulate samples, namely electron microscopy on both ash types will also be presented to relate the crystallographic and chemical properties to their ice nucleation abilities.

  3. Determination of combustible volatile matter in coal mine roadway dusts by backscatter of x-rays from a radioisotope source

    International Nuclear Information System (INIS)

    Ailwood, C.R.; Bunch, K.; Fookes, R.A.; Gravitis, V.L.; Watt, J.S.

    1977-01-01

    The combustible volatile matter in coal mine roadway dusts (CVM) has been determined using x-ray backscatter techniques. The correlation between x-ray and chemical techniques is reasonably good for the 92 samples from collieries on the Bulli seam, and the maximum error expected at the maximum level of 11.5 weight per cent CVM permitted in the N.S.W. Coal Mines Regulation Act, 1912, as amended, is about +- 2.5 weight per cent. This x-ray technique can be used only when the combustible volatile content of the coal matter (CVM) varies within a limited range, and a separate calibration is required for each coal seam. Portable equipment based on a radioisotope x-ray source and digital ratemeter makes possible simple and rapid analysis, and with adaptation to use in coal mines should lead to much more comprehensive testing of roadways and hence improved overall prevention of coal dust explosions. (author)

  4. The problem with coal-waste dumps inventory in Upper Silesian Coal Basin

    Science.gov (United States)

    Abramowicz, Anna; Chybiorz, Ryszard

    2017-04-01

    Coal-waste dumps are the side effect of coal mining, which has lasted in Poland for 250 years. They have negative influence on the landscape and the environment, and pollute soil, vegetation and groundwater. Their number, size and shape is changing over time, as new wastes have been produced and deposited changing their shape and enlarging their size. Moreover deposited wastes, especially overburned, are exploited for example road construction, also causing the shape and size change up to disappearing. Many databases and inventory systems were created in order to control these hazards, but some disadvantages prevent reliable statistics. Three representative databases were analyzed according to their structure and type of waste dumps description, classification and visualization. The main problem is correct classification of dumps in terms of their name and type. An additional difficulty is the accurate quantitative description (area and capacity). A complex database was created as a result of comparison, verification of the information contained in existing databases and its supplementation based on separate documentation. A variability analysis of coal-waste dumps over time is also included. The project has been financed from the funds of the Leading National Research Centre (KNOW) received by the Centre for Polar Studies for the period 2014-2018.

  5. Partitioning of selected trace elements in coal combustion products from two coal-burning power plants in the United States

    Science.gov (United States)

    Swanson, Sharon M.; Engle, Mark A.; Ruppert, Leslie F.; Affolter, Ronald H.; Jones, Kevin B.

    2013-01-01

    Samples of feed coal (FC), bottom ash (BA), economizer fly ash (EFA), and fly ash (FA) were collected from power plants in the Central Appalachian basin and Colorado Plateau to determine the partitioning of As, Cr, Hg, Pb, and Se in coal combustion products (CCPs). The Appalachian plant burns a high-sulfur (about 3.9 wt.%) bituminous coal from the Upper Pennsylvanian Pittsburgh coal bed and operates with electrostatic precipitators (ESPs), with flue gas temperatures of about 163 °C in the ESPs. At this plant, As, Pb, Hg, and Se have the greatest median concentrations in FA samples, compared to BA and EFA. A mass balance (not including the FGD process) suggests that the following percentages of trace elements are captured in FA: As (48%), Cr (58%), Pb (54%), Se (20%), and Hg (2%). The relatively high temperatures of the flue gas in the ESPs and low amounts of unburned C in FA (0.5% loss-on-ignition for FA) may have led to the low amount of Hg captured in FA. The Colorado Plateau plant burns a blend of three low-S (about 0.74 wt.%) bituminous coals from the Upper Cretaceous Fruitland Formation and operates with fabric filters (FFs). Flue gas temperatures in the baghouses are about 104 °C. The elements As, Cr, Pb, Hg, and Se have the greatest median concentrations in the fine-grained fly ash product (FAP) produced by cyclone separators, compared to the other CCPs at this plant. The median concentration of Hg in FA (0.0983 ppm) at the Colorado Plateau plant is significantly higher than that for the Appalachian plant (0.0315 ppm); this higher concentration is related to the efficiency of FFs in Hg capture, the relatively low temperatures of flue gas in the baghouses (particularly in downstream compartments), and the amount of unburned C in FA (0.29% loss-on-ignition for FA).

  6. 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....

  7. Generating a representative signal of coal moisture content to anticipate combustion control in thermal power stations

    Energy Technology Data Exchange (ETDEWEB)

    Prieto-Fernandez, Ismael; Luengo-Garcia, J. Carlos; Alonso-Hidalgo, Manuela; Ponte-Gutierrez, Daniel [Area de Maquinas y Motores Termicos, Universidad de Oviedo, Campus Universitario s/n 33203, Asturias Gijon (Spain)

    2002-06-01

    This article describes the possibilities of continuously measuring coal moisture in the boiler feeding circuit of a thermal power station so that the measurement can be used as a signal for the boiler combustion control system. To do so, in the first place, the point through which coal would be fed into the boiler was chosen. After studying the different parts of the circuit, the feeder was selected. Then, an installation was designed, at semi-industrial scale, faithfully reproducing the operation of a belt conveyor. In order to measure the moisture content, a microwave system was installed, and a large number of coal samples with different ranks and grain sizes was tested showing eventually the likelihood of the objective.

  8. N2 O A greenhouse gas released from the combustion of coals in fluidized beds

    International Nuclear Information System (INIS)

    Boavida, D.; Lobo, L. S.; Gulyurtlu, I.; Cabrita, I.

    1996-01-01

    This paper discusses the results of the experimental work investigating the formation of N-2 O and NO during fluidized bed combustion of coals, and of chars and volatiles produced from the pyrolysis of these coals. Ammonia (N H 3 ) and hydrogen cyanide (HCN) are shown to play important roles as gas phase precursors of both NO and N 2 O. The conversion of fuel-N through N H 3 and HCN to N 2 O and NO was studied using a fluidized bed combustor in the temperature range between 973 K and 1273 K, for two different coals. The results suggest that the principal contribution to N 2 O emission Originated from volatile-N, however, char-N could also have an important role, depending upon the temperature. 1 fig., 8 tabs

  9. Heavy metal content of combustible municipal solid waste in Denmark.

    Science.gov (United States)

    Riber, Christian; Fredriksen, Gry S; Christensen, Thomas H

    2005-04-01

    Data on the heavy metal composition of outlets from Danish incinerators was used to estimate the concentration of Zn, Cu, Pb, Cr, Ni, Cd, As and Hg in combustible waste (wet as received) at 14 Danish incinerators, representing about 80% of the waste incinerated in Denmark. Zn (1020 mg kg(-1)), Cu (620 mg kg(-1)) and Pb (370 mg kg(-1)) showed the highest concentration, whereas Hg (0.6 mg kg(-1)) showed the lowest concentration. The variation among the incinerators was in most cases within a factor of two to three, except for Cr that in two cases showed unexplained high concentrations. The fact that the data represent many incinerators and, in several cases, observations from a period of 4 to 5 years provides a good statistical basis for evaluating the content of heavy metals in combustible Danish waste. Such data may be used for identifying incinerators receiving waste with high concentrations of heavy metals suggesting the introduction of source control, or, if repeated in time, the data must also be used for monitoring the impacts of national regulation controlling heavy metals. It is recommended that future investigations consider the use of sample digestion methods that ensure complete digestion in order to use the data for determining the total heavy metal content of waste.

  10. Towards a coherent European approach for taxation of combustible waste.

    Science.gov (United States)

    Dubois, Maarten

    2013-08-01

    Although intra-European trade of combustible waste has grown strongly in the last decade, incineration and landfill taxes remain disparate within Europe. The paper proposes a more coherent taxation approach for Europe that is based on the principle of Pigovian taxation, i.e. the internalization of environmental damage costs. The approach aims to create a level playing field between European regions while reinforcing incentives for sustainable management of combustible waste. Three important policy recommendations emerge. First, integrating waste incineration into the European Emissions Trading System for greenhouse gases (EU ETS) reduces the risk of tax competition between regions. Second, because taxation of every single air pollutant from waste incineration is cumbersome, a differentiated waste incineration tax based on NO(x) emissions can serve as a second-best instrument. Finally, in order to strengthen incentives for ash treatment, a landfill tax should apply for landfilled incineration residues. An example illustrates the coherence of the policy recommendations for incineration technologies with diverse environmental effects. Copyright © 2013 Elsevier Ltd. All rights reserved.

  11. Catalytic combustion of gasified waste - Experimental part. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Jaeraas, Sven; Kusar, Henrik [Royal Institute of Technology, Stockholm (Sweden). Chemical Engineering and Technology

    2003-08-01

    This final report covers the work that has been performed within the project P 10547-2, 'Catalytic combustion of gasified waste - system analysis ORWARE'. This project is part of the research programme 'Energy from Waste' financed by the Swedish National Energy Administration. The project has been carried out at the division of Industrial Ecology and at the division of Chemical Technology at Royal Inst. of Technology. The aim of the project has been to study the potentials for catalytic combustion of gasified waste. The supposed end user of the technique is a smaller community in Sweden with 15,000-20,000 inhabitants. The project contains of two sub projects: an experimental part carried out at Chemical Technology and a system analysis carried out at Industrial Ecology. This report covers the experimental part of the project carried out at Chemical Technology. The aim for the experimental part has been to develop and test catalysts with long life-time and a high performance, to reduce the thermal-NO{sub x} below 5 ppm and to significantly reduce NO{sub x} formed from fuel-bound nitrogen. Different experimental studies have been carried out within the project: a set-up of catalytic materials have been tested over a synthetic mixture of the gasified waste, the influence of sulfur present in the gas stream, NO{sub x} formation from fuel bound nitrogen, kinetic studies of CO and H{sub 2} with and without the presence of water and the effects of adding a co-metal to palladium catalysts Furthermore a novel annular reactor design has been used to carry out experiments for kinetic measurements. Real gasification tests of waste pellets directly coupled to catalytic combustion have successfully been performed. The results obtained from the experiments, both the catalytic combustion and from the gasification, have been possible to use in the system analysis. The aim of the system analysis of catalytic combustion of gasified waste takes into consideration

  12. Solid-state nuclear magnetic resonance studies of phosphorus and boron in coals and combustion residues

    Energy Technology Data Exchange (ETDEWEB)

    Burchill, P.; Howarth, O.W.; Richards, D.G.; Sword, B.J. (British Coal Corporation, Stoke Orchard (UK). Coal Research Establishment)

    1990-04-01

    Solid-state nuclear magnetic resonance spectroscopy with magic angle spinning (MAS-n.m.r.) was used to study the occurrence of phosphorus and boron in coal, and their fate on combustion. These elements are only minor components of coal, but may significantly influence the utilization properties. {sup 31} P MAS-n.m.r. spectroscopy has confirmed that phosphorus is present in coal predominantly as apatite. This mineral is thermally stable under oxidizing conditions, and survives largely unaltered in high temperature ashes. However, under the semi-reducing bed conditions of certain stoker-fired boilers, it may be decomposed, volatilizing the phosphorus. The {sup 31}P MAS-n.m.r. spectra of bonded deposits show phosphorus in a markedly different coordination environment to that in apatite, the chemical shift suggesting aluminium phosphate or boron phosphate. {sup 11}B MAS-n.m.r. spectra of coals exhibit resonances due to both trigonal and tetrahedrally coordinated boron. Trigonal boron is probably present as tourmaline, but the nature of the tetrahedral boron is less certain; it may be held in tetrahedral sites within certain clay minerals. In common with phosphorus, boron may be volatilized during combustion. The {sup 11}B MAS-n.m.r. spectra of bonded deposits show a tetrahedral resonance with a chemical shift quite consistent with that of boron phosphate. 39 refs., 9 figs., 5 tabs.

  13. 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...

  14. 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)

  15. Non-combustible waste vitrification with plasma torch melter.

    Science.gov (United States)

    Park, J K; Moon, Y P; Park, B C; Song, M J; Ko, K S; Cho, J M

    2001-05-01

    Non-combustible radioactive wastes generated from Nuclear Power Plants (NPPs) are composed of concrete, glass, asbestos, metal, sand, soil, spent filters, etc. The melting tests for concrete, glass, sand, and spent filters were carried out using a 60 kW plasma torch system. The surrogate wastes were prepared for the tests. Non-radioactive Co and Cs were added to the surrogates in order to simulate the radioactive waste. Several kinds of surrogate prepared by their own mixture or by single waste were melted with the plasma torch system to produce glassy waste forms. The characteristics of glassy waste forms were examined for the volume reduction factor (VRF) and the leach rate. The VRFs were estimated through the density measurement of the surrogates and the glassy waste forms, and were turned out to be 1.2-2.4. The EPA (Environmental Protection Agency) Toxicity Characteristic Leaching Procedure (TCLP) was used to determine the leach resistance for As, Ba, Hg, Pb, Cd, Cr, Se, Co, and Cs. The leaching index was calculated using the total content of each element in both the waste forms and the leachant. The TCLP tests resulted in that the leach rates for all elements except Co and Cs were lower than those of the Universal Treatment Standard (UTS) limits. There were no UTS limits for Co and Cs, and their leach rate & index from the experiments were resulted in around 10 times higher than those of other elements.

  16. Technology for advanced liquefaction processes: Coal/waste coprocessing studies

    Energy Technology Data Exchange (ETDEWEB)

    Cugini, A.V.; Rothenberger, K.S.; Ciocco, M.V. [Pittsburgh Energy Technology Center, PA (United States)] [and others

    1995-12-31

    The efforts in this project are directed toward three areas: (1) novel catalyst (supported and unsupported) research and development, (2) study and optimization of major operating parameters (specifically pressure), and (3) coal/waste coprocessing. The novel catalyst research and development activity has involved testing supported catalysts, dispersed catalysts, and use of catalyst testing units to investigate the effects of operating parameters (the second area) with both supported and unsupported catalysts. Several supported catalysts were tested in a simulated first stage coal liquefaction application at 404{degrees}C during this performance period. A Ni-Mo hydrous titanate catalyst on an Amocat support prepared by Sandia National laboratories was tested. Other baseline experiments using AO-60 and Amocat, both Ni-Mo/Al{sub 2}O{sub 3} supported catalysts, were also made. These experiments were short duration (approximately 12 days) and monitored the initial activity of the catalysts. The results of these tests indicate that the Sandia catalyst performed as well as the commercially prepared catalysts. Future tests are planned with other Sandia preparations. The dispersed catalysts tested include sulfated iron oxide, Bayferrox iron oxide (iron oxide from Miles, Inc.), and Bailey iron oxide (micronized iron oxide from Bailey, Inc.). The effects of space velocity, temperature, and solvent-to-coal ratio on coal liquefaction activity with the dispersed catalysts were investigated. A comparison of the coal liquefaction activity of these catalysts relative to iron catalysts tested earlier, including FeOOH-impregnated coal, was made. These studies are discussed.

  17. Assessment of coal combustion in O{sub 2}+CO{sub 2} by equilibrium calculations

    Energy Technology Data Exchange (ETDEWEB)

    Zheng, Ligang [Natural Resources Canada, CANMET Energy Technology Centre, 1 Haanel Drive, Nepean, ON (Canada); Furimsky, Edward [IMAF Group, 184 Marlborough Avenue, Ottawa, ON (Canada)

    2003-04-15

    The facility for analysis of chemical thermodynamics (F*A*C*T) method based on the Gibbs energy minimization principle was used for the environmental assessment of coal combustion in O{sub 2}+CO{sub 2} mixture compared with that in air. For the former case, the calculations predict higher emissions of CO and lower emissions of NO{sub x}. For both combustion media, SO{sub x} emissions are governed by O{sub 2} concentration, whereas distribution of trace metals was unaffected when O{sub 2} concentration in the O{sub 2}+CO{sub 2} mixture approached that in air. The effect of O{sub 2}+CO{sub 2} mixture on the distribution of chlorine- and alkali-containing compounds in the vapor phase was minor compared with that in air. In spite of the large excess of CO{sub 2} in combustion medium, sulfation was the predominant reaction occurring in ash.

  18. Investigation on the ignition, thermal acceleration and characteristic temperatures of coal char combustion

    International Nuclear Information System (INIS)

    Zhang, Bin; Fu, Peifang; Liu, Yang; Yue, Fang; Chen, Jing; Zhou, Huaichun; Zheng, Chuguang

    2017-01-01

    Highlights: • A new thermal model and measuring method for the ignition temperature are proposed. • Ignition occurs in a region but not a point with ambient conditions changing. • Ignition region is measured from the minimum to maximum ignition temperature. • T_i_g_,_m_a_x of coal char in TG-DSC is in line with the ignition temperature of EFR. - Abstract: Through using a new thermal analysis model and a method of coal/char combustion, the minimum ignition temperature and minimum ignition heat of three different ranks of pulverized coal char were measured by simultaneous Thermogravimetry and Differential Scanning Calorimetry (TG-DSC) experiments. The results show that the ignition of coal char occurs in the range between the minimum ignition temperature and the inflection-point temperature. The thermal acceleration and its gradient G_T increase with increasing heating rate and decrease with increasing coal char rank. The higher the G_T of the coal char, the more easily the ignition occurs and more rapidly the burning and burnout occur. The data show that the G_T of coal char of SLH lignite is 1.6 times more than that of coal char of ZCY bituminous and JWY anthracite in ignition zone, and 3.4 times in burning zone. The characteristic temperatures increase with increasing temperature of prepared char, heating rate and char rank. Moreover, the T_i_g_,_m_a_x calculated in DSC experiment is approximately in line with the ignition temperature obtained in the entrained flow reactor, which demonstrates the feasibility of the proposed theory.

  19. Investigation of combustion and gasification mechanically activated coal fuel of various degrees of metamorphism on the 5-MW heat setup

    Directory of Open Access Journals (Sweden)

    Butakov Evgenii

    2017-01-01

    Full Text Available The technology of mechanochemical activation of combustion and gasification of coals is of unquestionable scientific and technical interest; an increase in chemical activity of coals at their mechanically activated grinding is associated with an increase in the rate of reaction of the coal substance. To study the combustion and gasification process, the reactor model with tangential scroll input of coal-air suspension and cylindrical reaction chamber was used at the 5-MW thermal power plant. The experiments were carried out with coals of G and SS grades of the Kuznetsk deposit. Coal, ground after the boiler’s standard mill, is fed by a feeder to the disintegrator; then, it enters the scroll inlet of the reactor burner with transport air. The suspension is ignited by a gas igniting device with the power of 50 kW. In experiments on combustion and gasification of fine coal performed at the temperature in the reaction chamber of 1000-1300°C and air excess α = 0.5-0.7, the data on concentrations of CO and H2 were obtained: for coal of grade G, concentration of H2 was 6.3% and concentration of CO was 15.3%; for coal of SS grade, concentration of H2 was 9.5% and concentration of CO was 15.6%.

  20. Radiation and convective heat transfer, and burnout in oxy-coal combustion

    Energy Technology Data Exchange (ETDEWEB)

    J.P. Smart; P. O' Nions; G.S. Riley [RWE npower, Swindon (United Kingdom)

    2010-09-15

    Measurements of radiative and convective heat transfer, and carbon-in-ash have been taken on the RWEn 0.5 MWth combustion test facility (CTF) firing two different coals under oxy-fuel firing conditions. The two coals fired were a Russian Coal and a South African Coal. Recycle ratios were varied within the range of 65-75% dependent on coal. Furnace exit O{sub 2} values were maintained at 3% and 6% for the majority of tests. Air firing tests were also performed to generate baseline data. The work gives a comprehensive insight into the effect of oxy-fuel combustion on both radiative and convective heat transfer, and carbon-in-ash compared to air under dry simulated recycle conditions. Results have shown peak radiative heat flux values are inversely related to the recycle ratio for the two coals studied. Conversely, the convective heat flux values increase with increasing recycle ratio. It was also observed that the axial position of the peak in radiative heat flux moves downstream away from the burner as recycle ratio is increased. A 'working range' of recycle ratios exists where both the radiative and convective heat fluxes are comparable with air. Carbon-in-ash (CIA) was measured for selected conditions. For air firing of Russian Coal, the CIA for follows and expected trend with CIA decreasing with increasing furnace exit O{sub 2}. The CIA data for the two recycle ratios of 72% and 68% for the same coal show that the CIA values are lower than for air firing for corresponding furnace exit O{sub 2} levels and vary little with the value of furnace exit O{sub 2}. CIA measurements were taken for the South African Coal for a range of recycle ratios at 3% and 6% furnace exit O{sub 2} levels. Results indicate that the CIA values are lower for higher furnace exit O{sub 2}. 32 refs., 11 figs., 1 tab.

  1. Control of spontaneous combustion of coal in goaf at high geotemperatureby injecting liquid carbon dioxide: inertand cooling characteristics of coal

    Science.gov (United States)

    Liu, Zhenling; Wen, Hu; Yu, Zhijin; Wang, Chao; Ma, Li

    2018-02-01

    The spontaneous combustion of coal in goaf at high geo temperatures is threatening safety production in coalmine. The TG-DSC is employed to study the variation of mass and energy at 4 atmospheres (mixed gases of N2, O2 and CO2) and heating rates (10°C/min) during oxidation of coal samples. The apparent activation energy and pre-exponential factor of coal oxidation decrease rapidly with increasing theCO2 concentration. Furthermore, its reaction rate is slow, its heat released reduces. Based on the conditions of 1301 face in the Longgucoalmine, a three-dimensional geometry model is developed to simulate the distributions stream field and temperature field and the variation characteristics ofCO2 concentration field after injecting liquidCO2. The results indicate that oxygen reached to depths of˜120m in goaf, 100m in the side of inlet air, and 10m in the side of outlet air before injecting liquidCO2. After injecting liquidCO2for 28.8min, the width of oxidation and heat accumulation zone is shortened by 20m, and the distance is 80m in the side of working face and 40˜60m in goafin the direction of dip affected by temperature.

  2. 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.

  3. 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.

  4. Resource recovery from coal fly ash waste: an overview study

    Energy Technology Data Exchange (ETDEWEB)

    Kumar, V.; Matsuda, M.; Miyake, M. [Okayama University, Okayama (Japan). Graduate School of Environmental Science

    2008-02-15

    Coal fly ash (CFA) is a useful byproduct of the combustion of coal. It is composed primarily of almost perfectly spherical aluminosilicate glass particles. This spherical characteristic and other characteristics of CFA should be exploited, rather than simply using CFA as inert filler for construction. Unfortunately, the presence of carbon residues and high levels of heavy metals has so far limited the uses of CFA. Forced leaching methods have been used to improve the technical and environmentally friendly qualities of CFA, but these processes do not seem to be economically viable. Actually, CFA is a major source of Si and Al for the synthesis of industrial minerals. Potential novel uses of CFA, e.g., for the synthesis of ceramic materials, ceramic membrane filters, zeolites, and geopolymers, are reviewed in this article with the intention of exploring new areas that will

  5. Collaborative Studies for Mercury Characterization in Coal and Coal Combustion Products, Republic of South Africa

    Science.gov (United States)

    Kolker, Allan; Senior, Constance L.; van Alphen, Chris

    2014-12-15

    Mercury (Hg) analyses were obtained for 42 samples of feed coal provided by Eskom, the national electric utility of South Africa, representing all 13 coal-fired power stations operated by Eskom in South Africa. This sampling includes results for three older power stations returned to service starting in the late 2000s. These stations were not sampled in the most recent previous study. Mercury concentrations determined in the present study are similar to or slightly lower than those previously reported, and input Hg for the three stations returned to service is comparable to that for the other 10 power stations. Determination of halogen contents of the 42 feed coals confirms that chlorine contents are generally low, and as such, the extent of Hg self-capture by particulate control devices (PCDs) is rather limited. Eight density separates of a South African Highveld (#4) coal were also provided by Eskom, and these show a strong mineralogical association of Hg (and arsenic) with pyrite. The density separates were used to predict Hg and ash contents of coal products used in South Africa or exported. A suite of 48 paired samples of pulverization-mill feed coal and fly ash collected in a previous (2010) United Nations Environment Programme-sponsored study of emissions from the Duvha and Kendal power stations was obtained for further investigation in the present study. These samples show that in each station, Hg capture varies by boiler unit and confirms that units equipped with fabric filters for air pollution control are much more effective in capturing Hg than those equipped with electrostatic precipitators. Apart from tracking the performance of PCDs individually, changes resulting in improved mercury capture of the Eskom fleet are discussed. These include Hg reduction through coal selection and washing, as well as through optimization of equipment and operational parameters. Operational changes leading to increased mercury capture include increasing mercury

  6. Coal flotation optimization using modified flotation parameters and combustible recovery in a Jameson cell

    International Nuclear Information System (INIS)

    Vapur, Hueseyin; Bayat, Oktay; Ucurum, Metin

    2010-01-01

    This study discusses a new coal flotation optimization approach. It is conducted using modified flotation parameters and combustible recovery. The experimental work was evaluated in two stages. In the first stage, recoveries (1, 2, 3, 5 and 8 min of flotation times) of Jameson flotation operating parameters were fitted to first-order kinetic model, R = R ∞ [1 - exp (-kt)] where R was recovery at t time, R ∞ was ultimate recovery and k was the first-order rate constant to draw the time recovery curves in the experimental study. Two parameters, the ultimate recovery (R ∞ ) and first-order rate constant (k), were then obtained from the model to fit an experimental time recovery curve. A modified flotation rate constant (K m ) defined as product of R ∞ and k, i.e., K m = R ∞ * k, and selectivity index (SI) defined as the ratio of the modified rate constant of coal to the modified rate constant of ash (SI)=K m of Coal/K m of Ash), which could be collectively called 'modified flotation parameters'. It was used to determine of the sub and upper values of operation variables. In the second one, combustible recovery (%) and ash content (%) were used to optimization of the Jameson flotation variables and it was found that d 80 = 0.250 mm particle size, 1/1 vegetable oil acids/kerosene ratio, 20% solids pulp density, 0.600 L/min wash water rate and 40 cm downcomer immersion dept could be used to separate efficiently coal from ash. Final concentrate was obtained with 94.83% combustible recovery and 17.86% ash content at optimum conditions after 8 min flotation time.

  7. Leaching and soil/groundwater transport of contaminants from coal combustion residues

    International Nuclear Information System (INIS)

    Hjelmar, O.; Hansen, E.A.; Larsen, F.; Thomassen, H.

    1992-01-01

    In this project the results of accelerated laboratory leaching tests on coal fly ash and flue gas desulfurization (FGD) products from the spray dryer absorption process (SDA) were evaluated by comparison to the results of large scale lysimeter leaching tests on the same residues. The mobility of chromium and molybdenum - two of the kev contaminants of coal combustion residue leachates - in various typical soil types was investigated by batch and column methods in the laboratory. Some of the results were confirmed by field observations at an old coal fly ash disposal site and by a lysimeter attenuation test with coal fly ash leachate on a clayed till. A large number of groundwater transport models and geochemical models were reviewed, and two of the models (Gove-Stollenwerk and CHMTRNS) were modified and adjusted and used to simulate column attenuation tests performed in the laboratory. One of the models (Grove-Stollenwerk) was used to illustrate a recommended method of environmental impact assessment, using lysimeter leaching data and laboratory column attenuation data to describe the emission and migration of Mo from a coal fly ash disposal site

  8. Effect of biomass blending on coal ignition and burnout during oxy-fuel combustion

    Energy Technology Data Exchange (ETDEWEB)

    B. Arias; C. Pevida; F. Rubiera; J.J. Pis [Instituto Nacional del Carbon, CSIC, Oviedo (Spain)

    2008-09-15

    Oxy-fuel combustion is a GHG abatement technology in which coal is burned using a mixture of oxygen and recycled flue gas, to obtain a rich stream of CO{sub 2} ready for sequestration. An entrained flow reactor was used in this work to study the ignition and burnout of coals and blends with biomass under oxy-fuel conditions. Mixtures of CO{sub 2}/O{sub 2} of different concentrations were used and compared with air as reference. A worsening of the ignition temperature was detected in CO{sub 2}/O{sub 2} mixtures when the oxygen concentration was the same as that of the air. However, at an oxygen concentration of 30% or higher, an improvement in ignition was observed. The blending of biomass clearly improves the ignition properties of coal in air. The burnout of coals and blends with a mixture of 79%CO{sub 2}-21%O{sub 2} is lower than in air, but an improvement is achieved when the oxygen concentration is 30 or 35%. The results of this work indicate that coal burnout can be improved by blending biomass in CO{sub 2}/O{sub 2} mixtures. 26 refs., 7 figs., 1 tab.

  9. 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

  10. Major and trace elements in coal bottom ash at different oxy coal combustion conditions

    CSIR Research Space (South Africa)

    Oboirien, BO

    2014-09-01

    Full Text Available This paper presents a detailed study on the effect of temperature on the concentration of 27 major and trace elements in bottom ash generated from oxy fuel-combustion. The major elements are Na, Mg, Al, K, Ca and Fe and the minor and trace elements...

  11. A new power station with clean combustion of coal residues financed by the Commission wins an international prize. Una nueva central electrica de combustion limpia de residuos de carbon financiada por la Comision gana un premio internacional

    Energy Technology Data Exchange (ETDEWEB)

    Furfari, S. (Commission of the European Communities, Brussels (Belgium). Directorate General for Energy, Energy Technology Unit)

    1993-07-01

    Between 1987 and 1989 10,55 million ecus were given by the European Commission's Demonstration Programme for the construction of the Emile Huchet power station using circulating fluidized bed combustion technology. The power station was constructed jointly by Charbonnages de France, COREAL, Stein Industrie and Lurgi. An important feature was its ability to burn coal preparation wastes cleanly. Despite burning poor quality fuel its emissions are well below the maximum standards. Other stations of this type are now planned in France.

  12. Revised users manual, Pulverized Coal Gasification or Combustion: 2-dimensional (87-PCGC-2): Final report, Volume 2. [87-PCGC-2

    Energy Technology Data Exchange (ETDEWEB)

    Smith, P.J.; Smoot, L.D.; Brewster, B.S.

    1987-12-01

    A two-dimensional, steady-state model for describing a variety of reactive and non-reactive flows, including pulverized coal combustion and gasification, is presented. Recent code revisions and additions are described. The model, referred to as 87-PCGC-2, is applicable to cylindrical axi-symmetric systems. Turbulence is accounted for in both the fluid mechanics equations and the combustion scheme. Radiation from gases, walls, and particles is taken into account using either a flux method or discrete ordinates method. The particle phase is modeled in a Lagrangian framework, such that mean paths of particle groups are followed. Several multi-step coal devolatilization schemes are included along with a heterogeneous reaction scheme that allows for both diffusion and chemical reaction. Major gas-phase reactions are modeled assuming local instantaneous equilibrium, and thus the reaction rates are limited by the turbulent rate mixing. A NO/sub x/ finite rate chemistry submodel is included which integrates chemical kinetics and the statistics of the turbulence. The gas phase is described by elliptic partial differential equations that are solved by an iterative line-by-line technique. Under-relaxation is used to achieve numerical stability. The generalized nature of the model allows for calculation of isothermal fluid mechanicsgaseous combustion, droplet combustion, particulate combustion and various mixtures of the above, including combustion of coal-water and coal-oil slurries. Both combustion and gasification environments are permissible. User information and theory are presented, along with sample problems. 106 refs.

  13. 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...

  14. Trends in the Rare Earth Element Content of U.S.-Based Coal Combustion Fly Ashes.

    Science.gov (United States)

    Taggart, Ross K; Hower, James C; Dwyer, Gary S; Hsu-Kim, Heileen

    2016-06-07

    Rare earth elements (REEs) are critical and strategic materials in the defense, energy, electronics, and automotive industries. The reclamation of REEs from coal combustion fly ash has been proposed as a way to supplement REE mining. However, the typical REE contents in coal fly ash, particularly in the United States, have not been comprehensively documented or compared among the major types of coal feedstocks that determine fly ash composition. The objective of this study was to characterize a broad selection of U.S. fly ashes of varied geological origin in order to rank their potential for REE recovery. The total and nitric acid-extractable REE content for more than 100 ash samples were correlated with characteristics such as the major element content and coal basin to elucidate trends in REE enrichment. Average total REE content (defined as the sum of the lanthanides, yttrium, and scandium) for ashes derived from Appalachian sources was 591 mg kg(-1) and significantly greater than in ashes from Illinois and Powder River basin coals (403 and 337 mg kg(-1), respectively). The fraction of critical REEs (Nd, Eu, Tb, Dy, Y, and Er) in the fly ashes was 34-38% of the total and considerably higher than in conventional ores (typically less than 15%). Powder River Basin ashes had the highest extractable REE content, with 70% of the total REE recovered by heated nitric acid digestion. This is likely due to the higher calcium content of Powder River Basin ashes, which enhances their solubility in nitric acid. Sc, Nd, and Dy were the major contributors to the total REE value in fly ash, based on their contents and recent market prices. Overall, this study shows that coal fly ash production could provide a substantial domestic supply of REEs, but the feasibility of recovery depends on the development of extraction technologies that could be tailored to the major mineral content and origins of the feed coal for the ash.

  15. 40 CFR 60.1810 - How do I monitor the load of my municipal waste combustion unit?

    Science.gov (United States)

    2010-07-01

    ... municipal waste combustion unit? 60.1810 Section 60.1810 Protection of Environment ENVIRONMENTAL PROTECTION... Guidelines and Compliance Times for Small Municipal Waste Combustion Units Constructed on or Before August 30... combustion unit? (a) If your municipal waste combustion unit generates steam, you must install, calibrate...

  16. 40 CFR 62.15020 - Can my small municipal waste combustion unit be exempt from this subpart?

    Science.gov (United States)

    2010-07-01

    ...) Municipal waste combustion units that combust only tires. Your unit is exempt from this subpart if three requirements are met: (1) Your municipal waste combustion unit combusts a single-item waste stream of tires and...) Plastics/rubber recycling units. Your unit is exempt from this subpart if four requirements are met: (1...

  17. Preliminary assessment of the health and environmental impacts of fluidized-bed combustion of coal as applied to electrical utility systems

    Energy Technology Data Exchange (ETDEWEB)

    None

    1977-02-01

    The objective of this study was to assess the health and environmental impacts of fluidized-bed combustion of coal (FBC), specifically as applied to base-load generation of electrical energy by utilities. The public health impacts of Fluidized-Bed Combustion (FBC) plants are expected to be quite similar to those for Low Sulfur Coal (LSC) and Flue Gas Desulfurization (FGD) plants because all appear to be able to meet Federal emission standards; however, there are emissions not covered by standards. Hydrocarbon emissions are higher and trace element emissions are lower for FBC than for conventional technologies. For FBC, based on an analytical model and a single emission data point, the polycyclic organic material decreases the anticipated lifespan of the highly exposed public very slightly. Added health protection due to lower trace element emissions is not known. Although there is a large quantity of solid wastes from the generating plant, the environmental impact of the FBC technology due to solid residue appears lower than for FGD, where sludge management requires larger land areas and presents problems due to the environmentally noxious calcium sulfite in the waste. Fixing the sludge may become a requirement that increases the cost of wet-limestone FGD but makes that system more acceptable. The potential for aquatic or terrestrial impacts from hydrocarbon emissions is low. If application of AFBC technology increases the use of local high-sulfur coals to the detriment of western low-sulfur coal, a sociological benefit could accrue to the FBC (or FGD) technology, because impacts caused by western boom towns would decrease. The infrastructure of areas that mine high-sulfur coal in the Midwest are better equipped to handle increased mining than the West.

  18. Flat-flame burner studies of pulverized-coal combustion. Experimental results on char reactivity

    Energy Technology Data Exchange (ETDEWEB)

    Peck, R.E.; Shi, L.

    1996-12-01

    Structure of laminar, premixed pulverized-coal flames in a 1-D reactor has been studied with emphasis on char reactivity. A 1.1-meter-long tube furnace accommodated high-temperature environments and long residence times for the laminar flames produced by a flat-flame, coal-dust burner. Experiments were conducted at different operating conditions (fuel type/size, fuel-air ratio). Measurements included solid sample composition, major gas species and hydrocarbon species concentrations, and gas- and particle-phase line-of-sight temperatures at different axial locations in flames. Degree of char burnout increased with coal volatiles content and decreased with coal particle size. Combustion in furnace was in oxidizer-deficient environment and higher burnout was achieved as the fuel-air ratio neared stoichiometric. For 0-45 {mu}m particles most of the fixed carbon mass loss occurred within 5 cm of the furnace inlet, and char reaction was slow downstream due to low oxidizer concentrations. Fixed carbon consumption of the 45-90 {mu}m particles generally was slower than for the small particles. About 40%-80% of the fixed carbon was oxidized in the furnace. Primary volatiles mass loss occurred within the first 4.5 cm, and more than 90% of the volatiles were consumed in the flames. The flames stabilized in the furnace produced less CH{sub 4} and H{sub 2} in the burnt gas than similar unconfined flames. NO concentrations were found to decrease along the furnace and to increase with decreasing fuel/air ratio. Temperature measurement results showed that gas-phase temperatures were higher than solid-phase temperatures. Temperatures generally decreased with decreasing volatiles content and increased as the equivalence ratio approached one. The results can be used to interpret thermochemical processes occurring in pulverized-coal combustion. (au) 15 refs.

  19. 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.

  20. Smog chamber study on the evolution of fume from residential coal combustion.

    Science.gov (United States)

    Geng, Chunmei; Wang, Kun; Wang, Wei; Chen, Jianhua; Liu, Xiaoyu; Liu, Hongjie

    2012-01-01

    Domestic coal stoves are widely used in countryside and greenbelt residents in China for heating and cooking, and emit considerable pollutants to the atmosphere because of no treatment of their exhaust, which can result in deteriorating local air quality. In this study, a dynamic smog chamber was used to investigate the real-time emissions of gaseous and particulate pollutants during the combustion process and a static smog chamber was used to investigate the fume evolution under simulate light irradiation. The real-time emissions revealed that the total hydrocarbon (THC) and CO increased sharply after ignition, and then quickly decreased, indicating volatilization of hydrocarbons with low molecular weight and incomplete combustion at the beginning stage of combustion made great contribution to these pollutants. There was evident shoulder peak around 10 min combustion for both THC and CO, revealing the emissions from vitrinite combustion. Additionally, another broad emission peak of CO after 30 min was also observed, which was ascribed to the incomplete combustion of the inertinite. Compared with THC and CO, there was only one emission peak for NOx, SO2 and particular matters at the beginning stage of combustion. The fume evolution with static chamber simulation indicated that evident consumption of SO2 and NOx as well as new particle formation were observed. The consumption rates for SO2 and NOx were about 3.44% hr(-1) and 3.68% hr(-1), the new particle formation of nuclei particles grew at a rate of 16.03 nm/hr during the first reaction hour, and the increase of the diameter of accumulation mode particles was evident. The addition of isoprene to the diluted mixture of the fume could promote 03 and secondary particle formation.

  1. Appendices 1-3 - the effects of combustion on ash and deposits from low rank coals

    Energy Technology Data Exchange (ETDEWEB)

    Ledger, R.C.; Ottrey, A.L.; Mackay, G.H.

    1985-12-01

    Thermomechanical analyses (TMA) of ashes derived from combustion of fourteen coal samples from Victorian and South Australian coalfields are presented in the results volumes of this report (Volume 2-4). This appendix describes the analytical equipment used, the modifications that were incorporated and the technique developed for analysis and interpretation of the data. To aid identification, limited numbers of analyses were performed on reference materials, the results of which are presented in this appendix. Analyses were performed on a modified Stanton Redcroft 790 series thermomechanical analyser. The aim was to identify components in the ashes and to gain an understanding of the sintering and fusion behaviour of the ashes up to temperatures encountered in large scale boilers. As part of the main project, ashes were also submitted to simultaneous Differential Thermal Analysis and Thermogravimetry (DTA-TG). For each coal burnt in this investigation the Test Bank 1 and precipitator ashes produced at a flame temperature of 1200/sup o/C and 3% excess oxygen were examined by TMA, as were ashes from tests at other flame temperatures and at 3% excess oxygen for four of the coals. This was to investigate the effects of variation in combustion conditions on ash properties. The results are presented in Volume 2-4 of this report as tables, giving details of events and assignments and as a formalised TMA pattern for each ash tested.

  2. Dew point measurements of flue gases in steam generators with brown coal combustion

    Energy Technology Data Exchange (ETDEWEB)

    Schinkel, W.

    1980-01-01

    This paper examines empirical data on sulfuric acid condensation and resulting internal corrosion in brown coal fired steam generators. Due to the high sulfur content in brown coal (0.5% to 5.0%) and relative short duration of the gases in the combustion chamber the concentrations of sulfur trioxide present in the flue gases can condense at the heat exchange surfaces of the steam generators. A number of diagrams show sulfuric acid dew point temperatures depending on brown coal sulfur content, the influence of combustion air supply on the dew point, and condensing speed and the rate of corrosion in relation to different heat exchange surface temperatures. The conclusion is made that a five-fold increase in corrosion can be caused by a 10 K higher flue gas dew point, a 5 K cooling of heating surfaces can also cause heavy corrosion at a certain dew point. Maximum corrosion results at 20 to 50 K differences between flue gas dew point and heat exchange surfaces. Optimum operation of steam generators with minimal internal corrosion requires the consideration of flue gas and heating surface temperatures as well as flue gas sulfur acid dew points. (10 refs.) (In German)

  3. Disposing of coal combustion residues in inactive surface mines: Effects on water quality

    International Nuclear Information System (INIS)

    Kim, A.G.; Ackman, T.E.

    1994-01-01

    The disposal of coal combustion residues (CCR) in surface and underground coal mines can provide a stable, low-maintenance alternative to landfills, benefiting the mining and electric power industries. The material may be able to improve water quality at acid generating abandoned or reclaimed coal mine sites. Most combustion residues are alkaline, and their addition to the subsurface environment could raise the pH, limiting the propagation of pyrite oxidizing bacteria and reducing the rate of acid generation. Many of these CCR are also pozzolanic, capable of forming cementitious grouts. Grouts injected into the buried spoil may decrease its permeability and porosity, diverting water away from the pyritic material. Both mechanisms, alkaline addition and water diversion, are capable of reducing the amount of acid produced at the disposal site. The US Bureau of Mines is cooperating in a test of subsurface injection of CCR into a reclaimed surface mine. Initially, a mixture of fly ash, lime, and acid mine drainage (AMD) sludge was injected. Lime was the source of calcium for the formation of the pozzolanic grout. Changes in water quality parameters (pH, acidity, anions, and trace metals) in water samples from wells and seeps indicate a small but significant improvement after CCR injection. Changes in the concentration of heavy metals in the water flowing across the site were apparently influenced by the presence of flyash

  4. Effect of primary air content on formation of nitrogen oxides during combustion of Ehkibastuz coal

    Energy Technology Data Exchange (ETDEWEB)

    Kotler, V.R.; Imankulov, Eh.R.

    1986-01-01

    Investigations are discussed carried out in a pilot plant at the Kaz. Power Engineering Scientific Research Institute into the effect of the amount of primary air in coal-dust flame on the final concentration of nitrogen oxides in flue gases. The tests were carried out in a 7500 mm high, 1600 mm dia vertical cylindrical combustion chamber having type P-57 burner, and air dispersed fuel plus additional air supplies located at the top. Amounts of coal dust fed by a drum feeder along the air pipe varied from 100-600 kg/h. The required air was supplied by 5000 m/sup 3//h Type TK-700/5 blowers at 0.04 MPa. Ehkibastuz coal samples contained: 1.3% moisture; 48.1% ash; 38.02% carbon; 2.56% hydrogen; 0.73% sulfur; 0.60% nitrogen; heat of combustion was 14.3 MJ/kg. Results obtained indicate that variations in the amount of primary air in swirl flow burners affect formation of fuel nitrogen; there is an optimum volume at which minimum quantities of nitrogen oxides are formed. Either an increase or decrease in the primary air results in a rise in nitrogen oxide concentration. 3 references.

  5. Gasification in pulverized coal flames. Final report (Part I). Pulverized coal combustion and gasification in a cyclone reactor: experiment and model

    Energy Technology Data Exchange (ETDEWEB)

    Barnhart, J. S.; Laurendeau, N. M.

    1979-05-01

    A unified experimental and analytical study of pulverized coal combustion and low-BTU gasification in an atmospheric cyclone reactor was performed. Experimental results include several series of coal combustion tests and a coal gasification test carried out via fuel-rich combustion without steam addition. Reactor stability was excellent over a range of equivalence ratios from .67 to 2.4 and air flowrates from 60 to 220 lb/hr. Typical carbon efficiencies were 95% for air-rich and stoichiometric tests and 80% for gasification tests. The best gasification results were achieved at an equivalence ratio of 2.0, where the carbon, cold gas and hot gas efficiencies were 83, 45 and 75%, respectively. The corresponding product gas heating value was 70 BTU/scf. A macroscopic model of coal combustion in the cyclone has been developed. Fuel-rich gasification can also be modeled through a gas-phase equilibrium treatment. Fluid mechanics are modeled by a particle force balance and a series combination of a perfectly stirred reactor and a plug flow reactor. Kinetic treatments of coal pyrolysis, char oxidation and carbon monoxide oxidation are included. Gas composition and temperature are checked against equilibrium values. The model predicts carbon efficiency, gas composition and temperature and reactor heat loss; gasification parameters, such as cold and hot gas efficiency and make gas heating value, are calculated for fuel-rich conditions. Good agreement exists between experiment and theory for conditions of this investigation.

  6. Mercury and halogens in coal--Their role in determining mercury emissions from coal combustion

    Science.gov (United States)

    Kolker, Allan; Quick, Jeffrey C.; Senior, Connie L.; Belkin, Harvey E.

    2012-01-01

    Mercury is a toxic pollutant. In its elemental form, gaseous mercury has a long residence time in the atmosphere, up to a year, allowing it to be transported long distances from emission sources. Mercury can be emitted from natural sources such as volcanoes, or from anthropogenic sources, such as coal-fired powerplants. In addition, all sources of mercury on the Earth's surface can re-emit it from land and sea back to the atmosphere, from which it is then redeposited. Mercury in the atmosphere is present in such low concentrations that it is not considered harmful. Once mercury enters the aquatic environment, however, it can undergo a series of biochemical transformations that convert a portion of the mercury originally present to methylmercury, a highly toxic organic form of mercury that accumulates in fish and birds. Many factors contribute to creation of methylmercury in aquatic ecosystems, including mercury availability, sediment and nutrient load, bacterial influence, and chemical conditions. In the United States, consumption of fish with high levels of methylmercury is the most common pathway for human exposure to mercury, leading the U.S. Environmental Protection Agency (EPA) to issue fish consumption advisories in every State. The EPA estimates that 50 percent of the mercury entering the atmosphere in the United States is emitted from coal-burning utility powerplants. An EPA rule, known as MATS (for Mercury and Air Toxics Standards), to reduce emissions of mercury and other toxic pollutants from powerplants, was signed in December 2011. The rule, which is currently under review, specifies limits for mercury and other toxic elements, such as arsenic, chromium, and nickel. MATS also places limits on emission of harmful acid gases, such as hydrochloric acid and hydrofluoric acid. These standards are the result of a 2010 detailed nationwide program by the EPA to sample stack emissions and thousands of shipments of coal to coal-burning powerplants. The United

  7. Evaluation of AFBC co-firing of coal and hospital wastes. Technical report, January 1989--August 1990

    Energy Technology Data Exchange (ETDEWEB)

    1991-02-01

    The purpose of this program is to expand the use of coal by utilizing CFB (circulating fluidized bed) technology to provide an environmentally safe method for disposing of waste materials. Hospitals are currently experiencing a waste management crisis. In many instances, they are no longer permitted to burn pathological and infectious wastes in incinerators. Older hospital incinerators are not capable of maintaining the stable temperatures and residence times necessary in order to completely destroy toxic substances before release into the atmosphere. In addition, the number of available landfills which can safely handle these substances is decreasing each year. The purpose of this project is to conduct necessary research investigating whether the combustion of the hospital wastes in a coal-fired circulating fluidized bed boiler will effectively destroy dioxins and other hazardous substances before release into the atmosphere. If this is proven feasible, in light of the quantity of hospital wastes generated each year, it would create a new market for coal -- possibly 50 million tons/year.

  8. Behavior of radioactive metal surrogates under various waste combustion conditions

    International Nuclear Information System (INIS)

    Yang, Hee Chul; Lee, Jae Hee; Kim, Jung Guk; Yoo, Jae Hyung; Kim, Joon Hyung

    2002-01-01

    A laboratory investigation of the behavior of radioactive metals under the various waste combustion atmospheres was conducted to predict the parameters that influence their partitioning behavior during waste incineration. Neodymium, samarium, cerium, gadolinium, cesium and cobalt were used as non-radioactive surrogate metals that are representative of uranium, plutonium, americium, curium, radioactive cesium, and radioactive cobalt, respectively. Except for cesium, all of the investigated surrogate metal compounds converted into each of their stable oxides at medium temperatures from 400 to 900 .deg. C, under oxygen-deficient and oxygen-sufficient atmospheres (0.001-atm and 0.21-atm O 2 ). At high temperatures above 1,400 .deg. C, cerium, neodymium and samarium in the form of their oxides started to vaporize but the vaporization rates were very slow up to 1500 .deg. C. Inorganic chlorine (NaCl) as well as organic chlorine (PVC) did not impact the volatility of investigated Nd 2 O 3 , CoO and Cs 2 O. The results of laboratory investigations suggested that the combustion chamber operating parameters affecting the entrainment of particulate and filtration equipment operating parameters affecting particle collection efficiency be the governing parameters of alpha radionuclides partitioning during waste incineration

  9. The properties of the nano-minerals and hazardous elements: Potential environmental impacts of Brazilian coal waste fire.

    Science.gov (United States)

    Civeira, Matheus S; Pinheiro, Rafael N; Gredilla, Ainara; de Vallejuelo, Silvia Fdez Ortiz; Oliveira, Marcos L S; Ramos, Claudete G; Taffarel, Silvio R; Kautzmann, Rubens M; Madariaga, Juan Manuel; Silva, Luis F O

    2016-02-15

    Brazilian coal area (South Brazil) impacted the environment by means of a large number of coal waste piles emplaced over the old mine sites and the adjacent areas of the Criciúma, Urussanga, and Siderópolis cities. The area studied here was abandoned and after almost 30 years (smokeless visual) some companies use the actual minerals derived from burning coal cleaning rejects (BCCRs) complied in the mentioned area for industry tiles or refractory bricks. Mineralogical and geochemical similarities between the BCCRs and non-anthropogenic geological environments are outlined here. Although no visible flames were observed, this study revealed that auto-combustion existed in the studied area for many years. The presence of amorphous phases, mullite, hematite and other Fe-minerals formed by high temperature was found. There is also pyrite, Fe-sulphates (eg. jarosite) and unburnt coal present, which are useful for comparison purposes. Bad disposal of coal-dump wastes represents significant environmental concerns due to their potential influence on atmosphere, river sediments, soils and as well as on the surface and groundwater in the surroundings of these areas. The present study using advanced analytical techniques were performed to provide an improved understanding of the complex processes related with sulphide-rich coal waste oxidation, spontaneous combustion and mineral formation. It is reporting huge numbers of rare minerals with alunite, montmorillonite, szomolnokite, halotrichite, coquimbite and copiapite at the BCCRs. The data showed the presence of abundant amorphous Si-Al-Fe-Ti as (oxy-)hydroxides and Fe-hydro/oxides with goethite and hematite with various degrees of crystallinity, containing hazardous elements, such as Cu, Cr, Hf, Hg, Mo, Ni, Se, Pb, Th, U, Zr, and others. By Principal Component Analysis (PCA), the mineralogical composition was related with the range of elemental concentration of each sample. Most of the nano-minerals and ultra-fine particles

  10. Application of hydrothermally crystallized coal ashes for waste water treatment, 2

    Energy Technology Data Exchange (ETDEWEB)

    Kato, Yasuhiko; Kakimoto, Kohji; Ogawa, Hiroaki; Tomari, Masao; Sakamoto, Eiji; Asahara, Teruzo

    1986-11-01

    To provide an application of combustion coal ash, hydrothermal reaction of fly ash (FA) and clinker ash (CA) is performed and an investigation is carried out to determine the capability of the P type zeolite produced from these ashes to adsorb heavy metal ions. Hydrothermal reaction of FA and CA at 95 - 100 deg C is conducted with various concentrations of sodium hydroxide for various reaction times. Both types of ash are found to easily undergo crystallization to form P type zeolite (PZ) and hydroxy sodalite (HS) when treated with a sodium hydroxide solution (sodium hydroxide/coal ash = 10 v/w) for 18 hours. The FA-PZ and CA-PZ produced by the hydrothermal treatment have degrees of crystallinity in the range of 40 - 60 percent. It is seen that the degree of crystallinity gradually increases with increasing treatment time. The crystallinity of hydrothermally treated coal ash is also shown to have good correlation with the base substitution capacity and the maximum adsorption of ammonium ion. Furthermore, they are shown to effectively adsorb metal ions, in particular those of lead, cadmium and strontium. It is suggested that they may serve as an enrichment agent for low-level radioactive nuclides produced in nuclear power plants. They also seem to have the possibility of serving as a metal elution preventive for industrial wastes of some special types. (Nogami, K.).

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

    Energy Technology Data Exchange (ETDEWEB)

    ROBERT H. HURT

    1998-09-08

    temperatures approaching 3000 o C. For the measurement of temperature histories an optical diagnostic is being developed that offers sufficient spatial resolution to distinguish the sample temperature from the substrate temperature. The optical diagnostic is based on a CID camera, a high-power lens, and movable mirrors to projecting multiple, filtered images onto a single chip. Oxidation kinetics are measured on the heat treated samples by a nonisothermal TGA technique. Task 2 Thermal deactivation kinetics. The goal of this task is to quantify thermal char deactivation as a function of temperature history and parent coal, with an emphasis on inert environments at temperatures and times found in combustion systems. The results are to be cast in the form of deactivation kinetics useful for incorporation in combustion models. Task 3 Crystal structure characterization. Crystal structure characterization provides important insight into the mechanisms of thermal char deactivation, and the degree of crystalline transformations has shown a strong correlation with reactivity changes in recent combustion studies [Davis et al., 1992, Beeley et al., 1996]. This task seeks to improve our understanding of char carbon crystalline transformations under combustion conditions by analyzing a large set of HRTEM fringe images for a series of flame-generated chars whose reactivities have been previously reported [Hurt et al., 1995, Beeley et al., 1996]. As a first step, a new technique is being developed for the quantitative analysis of fringe images, extending previous work to allow measurement of a complete set of crystal structure parameters including mean layer size, mean stacking height, interlayer spacing, layer curvature, amorphous fraction, and degree of anisotropy. The resulting database will revealing, at a very fundamental level, the basic differences in char crystal structure due to parent coal rank and to temperature history in the range of interest to combustion systems.

  12. Modelling NO[sub x] formation in coal particle combustion at high temperature: an investigation of the devolatilisation kinetic factors

    Energy Technology Data Exchange (ETDEWEB)

    Jones, J.M.; Patterson, P.M.; Pourkashanian, M.; Williams, A.; Arenillas, A.; Rubiera, F.; Pis, J.J. (University of Leeds, Leeds (United Kingdom). Dept. of Fuel and Energy)

    1999-08-01

    Coal combustion computational fluid dynamic (CFD) models are a powerful predictive tool in combustion research. In existing coal combustion CFD models, the process is described by three kinetic rates: coal devolatilizaton, volatile combustion and char combustion. A general, representative devolatilisation rate for coal is a matter of some contention, and measured rates depend upon the type of experimental system employed in their determination. Thus the reported rates vary considerably, causing difficulties in the choice of rate expression for CFD modelling applications. In this investigation, a laminar flow CFD model of a drop-tube furnace was used to assess the influence of global devolatilisation rates on overall combustion behaviour, and in particular, NOx emissions. The rates chosen include some of the common expressions employed by researchers in the field. Analysis, and comparison of the modelling results with those of the experimental indicated that a single-step devolatilisation rate can give satisfactory profiles. This rate can be calculated from the tar release rate using a network model such as FG-DVC (functional group, depolymerisation, vaporisation and cross-linking) together with the nitrogen partitioning between gas and char during pyrolysis. The use of these single-step models result in good predictions of NOx, and the inclusion of soot/NOx interactions can improve the mode significantly to give an excellent agreement with experimental results. 2 refs., 4 figs., 3 tabs.

  13. Environmental assessment of coal waste mounds in Japan using remote sensing techniques

    Energy Technology Data Exchange (ETDEWEB)

    Lewis, A J; Gotoh, K; Aoyama, K; Aoki, S [Louisiana State University, Baton Rouge, LA (United States). Department of Geography and Anthropology

    1993-01-01

    Focuses on the application of remote sensing techniques to the study of coal waste mounds. The situation at the coal waste mounds in Fukuoka, Japan is cited. Guidelines on film parameters, photographic keys and tasks required to inventory, monitor and manage coal waste mounds in Japan are addressed. Application of photogrammetry, remote sensing, aerial photography and satellite imagery techniques in monitoring spoil banks is reviewed. Applicability of the techniques is discussed. 24 refs.

  14. Some aspects of emission and volatization of trace elements on coal combustion

    International Nuclear Information System (INIS)

    Sanchez, J.C.D.; Formoso, M.L.L.; Bristoti, A.

    1987-01-01

    The present research work was carried out an industrial plant which uses a mixture of coals from Leao and Recreio mines for steam generation in a bioler with a capacity of 160t/h of steam. Coal samples from Leao, Recreio and the correspondent mixture were taken, as well as samples from the products of combustion. The present study fundamentally aims at assessing the emission of trace elements and major components of mineral matter, present in coal, in order to bring subsidies for a more efficient control over atmospheric, terrestrial and water pollution. Emissions of trace elements: As, B, Be, Cd, Cl, Co, Cr, Cu, F, Ga, Hg, Mn, Mo, Ni, Pb, S, Sn, V, Zn, Zr, and major elements: Si, Al, Ca, Mg, Ti, Fe, K and P, were calculated. Moreover, the average emission of particulate matter to the atmosphere was evaluated. In the present work, analytical procedures as X-ray spectroscopy and absorption spectroscopy and techniques used for the determination of F and Cl in Brazilian coals are cited. (author) [pt

  15. New process of co-coking of waste plastics and blend coal

    Energy Technology Data Exchange (ETDEWEB)

    Liao, H.; Yu, G.; Zhao, P. (and others) [Shougang Technical Research Institute, Beijing (China)

    2006-07-01

    To recycle and reuse waste plastics, as well as to get a new resource of coking, co-coking process of waste plastics and blend coal has been developed by Nippon Steel. However, the ratio of waste plastics in blend coal should be limited in the range of 1% to maintain the coke strength. This paper suggested a new process of co-coking of waste plastics and blend coal. The new process can add the waste plastics ratio up to 2-4%; when the waste plastics ratio is 2%, the coke strength after reaction with CO{sub 2} (CSR) increased 8%. 8 refs., 2 figs., 3 tabs.

  16. Characterization of Oxy-combustion Impacts in Existing Coal-fired Boilers

    Energy Technology Data Exchange (ETDEWEB)

    Adams, Bradley R. [Univ. of Utah, Salt Lake City, UT (United States); Fry, Andrew R. [Univ. of Utah, Salt Lake City, UT (United States); Senior, Constance L. [Univ. of Utah, Salt Lake City, UT (United States); Shim, Hong Shig [Univ. of Utah, Salt Lake City, UT (United States); Otten, Brydger Van [Univ. of Utah, Salt Lake City, UT (United States); Wendt, Jost [Univ. of Utah, Salt Lake City, UT (United States); Shaddix, Christopher [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Tree, Dale [Brigham Young Univ., Provo, UT (United States)

    2010-06-01

    This report summarizes Year 2 results of a research program designed to use multi-scale experimental studies and fundamental theoretical models to characterize and predict the impacts of retrofit of existing coal-fired utility boilers for oxy-combustion. Year 2 focused extensively on obtaining experimental data from the bench-scale, lab-scale and pilot-scale reactors. These data will be used to refine and validate submodels to be implemented in CFD simulations of full-scale boiler retrofits. Program tasks are on schedule for Year 3 completion. Both Year 2 milestones were completed on schedule and within budget.

  17. Transformations of inorganic coal constituents in combustion systems. Volume 3, Appendices: Final report

    Energy Technology Data Exchange (ETDEWEB)

    Helble, J.J. [ed.; Srinivasachar, S.; Wilemski, G.; Boni, A.A. [PSI Technology Co., Andover, MA (United States); Kang, Shim-Gyoo; Sarofim, A.F.; Graham, K.A.; Beer, J.M. [Massachusetts Inst. of Tech., Cambridge, MA (United States); Peterson, T.W.; Wendt, O.L.; Gallagher, N.B.; Bool, L. [Arizona Univ., Tucson, AZ (United States); Huggins, F.E.; Huffman, G.P.; Shah, N.; Shah, A. [Kentucky Univ., Lexington, KY (United States)

    1992-11-01

    This report contains the computer codes developed for the coal combustion project. In Subsect