- Email: [email protected]
Mercury control research: effects of fly ash and flue gas parameters on mercury speciation
15 Environment
(pollution, health protection,
safety)
This study was focused at estimating the human health risk of the general and working population living in the region polluted by arsenic for more than 40 years, from combustion of coal with high arsenic content in the power plant. The exposure to arsenic from inhalation was under investigation. A study period of 40 years (1973-1993) was chosen. The study period was defined taking into account, besides the availability of data, the temporal patterns of the technology processes and the trends over time of environmental concentrations. The results from the arsenic risk assessment study were used for the evaluation of the health risk for different population groups in the polluted areas and for different professions of workers exposed to As in a power plant. The results are applicable for the evaluation of risk in real conditions, for health surveillance and for remedial changes and a potential suggestion on technology improvement. 02fOO665 High efficiency utilization of fossil fuel and environmental protection technology Sema, T., Makino, H. Kagaku Kogaku, 2000, 64, (4), 167-171. (In Japanese) A review, with six references, of the title subject, fossil fuel resources, pollution prevention in utilizing fossil fuels in power plants, and future trends of fossil fuel utilization. 02fOO666 Impact of erosion-transported overburden dump materials on water aualitv in Lake Cosouden evolved from a former open cast lignite mine south of leipzig, Germany Abel, A. er al. Environ. Geol. (Berlin), 2000, 39, (6), 683-688. Acidification is the most common water quality problem in lakes created from previous open cast lignite mines. Aeration of aquifers and dump materials from mining activities causes pyrite oxidation. Pyrite oxidation products are stored in pore water, minerals, and at the exchange complexes of aquifers and dump sediment. Rain fall runoff transports sediment on the dump slope into lakes. Elutriation of this sediment within lakes releases either acid-producing or acid-neutralizing agents. At a test site south of Leipzig, Germany, annual erosion rates were quantified by water erosion models (RUSLE, EROSION 2D, PEPP) and field measurements. They ranged from 300 to 900 tons/ ha. Hydrogen ion equivalence release or binding at the sediment elutriation was computed from laboratory analysis of pore water quality, ion exchange complex, and sediment mineral composition. Two of three investigated sediment contained 3 mmol (equivalence) acidity/ 100 g dry sediment and revealed saturation with respect to jarosite, jurbanite, and gypsum. In the third sediment, 6 mmol (equivalence) alkalenity/lOO g dry sediment was obtained. Annual net acidity influx was calculated to be ~0.5 million mol (equivalent) for the lake at the test side. 02/00667 Impact of sodium chloride on coal combustion emissions Liu, Y. er al. Xi’an Jiaotong Daxue Xuebao, 2000, 34, (5), 42-45, 58. (In Chinese) The effect of sodium chloride on the coal combustion emissions is investieated bv usine a thermoeravimetric analvser at different heating rates 00, 20’and 50 degrees-per min) from room temperature to 1000°C. The experimental data can be used to better understand the role of chlorides when coal and solid wastes are combusted together in boilers. The experimental results show that sodium chloride can reduce sulphur dioxide emission in coal combustion process and enhance desulphurization. 02/00666 Improved containment transport modelling for hypothetical accidents in fusion power plants Han, W.E., Karditsas, P.J. Fusion Engineering and Design, 2000, 51-52, 535-542. We report here improvements to a code, FUSCON, developed for the SEAFP-2 (Safety and Environmental Aspects of Fusion Power) study to model containment transport and release to the environment. The previous version of FUSCON did not include heat transfer to the wall, accounted for condensation for only a limited set of conditions, and hence placed restrictions on some of the containment parameters investigated. The improvements described involve modelling of postaccident convective transport in the containment system. This is a good basis for enhancement of the model to include mass transfer effects associated with condensation. Three-dimensional, computational-fluiddynamics, finite-element calculations have guided the derivation of a computationally economic model of convective containment transport. The efficiency of the model will ensure that FUSCON is still sufficiently fast-running to be used to study confinement system optimization and selection. 02/00669 degassing Bukhantsov, Russian) 70
Improvement A.I., Porubai,
of mining safety based on effective V.V.
Fuel and Energy Abstracts
Ugol’ Ukr.,
1999, 10, 42-50.
January 2002
(In
Based on the advantages and disadvantages of basic coal seam degassing methods, a combined pneumatic-hydraulic technology was developed for methane removal from coal stratum via the apertures bored from the ground surface. This method involves the hydrodynamic treatment of the stratum with a limited volume of liquid supplemented with inert substances, which increase the mass transfer of the liquid, thereby ensuring the opening of natural fracture systems oriented toward the aperture and the further development of these systems during air pumping into the stratum under different regimes with the possibilitv of using additional intensifvina effects. In experiments conducted in mines, the use of this method decreased the emissions of CH., into the mine drifts by 57-66%. 02/00690 Indoor coal combustion emissions, GSTMl and GSTTl genotypes? and lung cancer risk: a case-control study in Xuan Wer, China Lan, Q. et al. Cancer Epidemiol., Biomarkers Prev., 2000, 9, (6). 605608. Lung cancer mortality rates in Xuan Wei County, China are among the highest in the country and has been associated with exposure to indoor smoky coal emissions that contain high levels of polycyclic aromatic hvdrocarbons. This risk mav be modified bv variation in metabolic genes, including GSTMl, which encodes an enzyme known to detoxify polycyclic aromatic hydrocarbons. To study the relation between GST genotypes and lung cancer risk in Xuan Wei County, we analysed GSTMl and GSTTl genotypes in a population. A total of 122 lung cancer patients and 122 controls, individually matched by age, sex, and home fuel type, were studied. Compared to subjects who used cl30 tons smokv coal durine their lifetime. heavier users f>130 tons) had a 2.4-fold (95% confid&ce interval, ‘1.3-4.4) increasid risk of lung cancer. The GSTMl-null genotype was associated with a 2.3-fold (95% confidence interval, 1.3-4.2) increased risk of lung cancer. There was some evidence that smoky coal use was more strongly associated with lung cancer risk among GSTMI-null versus GSTMl-positive individuals. In contrast, the GSTTl genotype was not significantly associated with lung cancer risk. Data suggest that the GSTMI-null genotype may enhance susceptibility to air pollution from indoor coal combustion emissions. 02/00691 Liquid fuel additive for improved combustion efficiencv and reduced noxious emissions Horio, T. ;I al. Faming Zhuanli Shenqing Gongkai Shuomingshu CN 1,210,135 (Cl. ClOL1/22), 10 Mar 1999, Appl. 97,114,244, 29 Aug 1997. 6. (In Chinese) The liquid fuel additive is composed of gasoline, diesel oil or kerosene 100 L, succinimide 0.02-0.06, amine oxide 3-6, synthetic ester 0.5-1.5, Paradyne 0.5-4, dialkyl diphenylamines 0.1-0.5, tolyl di-Ph phosphates 0.02-0.05, methylphenyldiamine 0.1-0.3, zinc dialkyldithiosulfate 0.050.1, and N,N’-bis(salicylidene)-1,2-diaminobenzene 0.3-0.8 g. 02/00692 Means to decrease nitrogen oxides emissions during firing of coke furnaces Pyrikov, A.N., Chernyshev, V.N. Sral’, 1999, 12, 81-85. (In Russian) The means for controlling NO, emissions from coke ovens are discussed. Flue gas recirculation, staged air firing, and catalytic reduction of nitrogen oxides are cited as effective. 02/00693 Mercury control research: effects of fly ash and flue gas parameters on mercury speciation Lee, C.W. et al. Annu. Waste-to-Energy Co@.. Proc. Spec. Conf., 6th, 1998, 221-238. In flue gas from combustion systems, mercury (Hg) is typically in the vapour phase at flue gas cleaning temperatures, and the control of Hg emissions is dependent on the specific Hg compounds that are present (soeciation) and the tvue of air oollution devices emoloved. In drv and se-mi-dry scrubbing sysiems, the’ control of Hg emiss’ions is dependent on the sorption of Hg by particulate matter (PM) which can be subsequently collected in a PM control device. In wet scrubbing systems, the principal mechanisms of control are the removal of sol. forms of Hg and the collection of particle-bound Hg. At combustion temperatures, Hg is btlieved to be predominantly in the form of elemental mercury (Hg ). As the flue #as is cooled, thermochemical equilibrium calculations indicate the Hg IS converted primarily to ionic mercury (Hg++) in the form of mercuric oxide (HgO) or mercuric chloride (HgClz). Hg” is insoluble in water, but HgO has a low solubility while HgClz is highly soluble. The oxidation of Hg” to an ionic form depends on the temperature, the time-temperature profile, the flue gas composition, the reaction kinetics, and the presence of solids that may catalyse reactions. Bench-scale experiments were conducted to study the effects of flue gas and fly ash parameters on the oxidation of Hg” in simulated flue gases containing hydrogen chloride (HCl). Gas-phase studies indicated that the in-flieht oostcombustion oxidation‘of Hg” in the presence of HCl is very slow’ and proceeds at measurable rates only at high temperatures (> 700°C) and high HCl concentrations (>200 ppm). The presence of sulphur dioxide
15 Environment (SO*) and water vapour in the simulated flue gas significantly inhibited the gas-phase oxidation of Hga. On the other hand, preliminary investigation indicated that the gas-phase reaction of Hg’with chlorine (Cl,) is fast. At 40°C and in the presence of 50 ppm Clz, 100% of the input Hg’ was oxidized to HgClz in less than 2 s, indicating that Clz is a much more active chlorinating agent than HCI. The effects of fly ash composition were investigated using a fixed-bed reactor containing different model fly ashes (simulated fly ash) consisting of mixtures of some major components found in coal and municipal waste combustor (MWC) fly ashes. Work to date has focused on the potential catalytic oxidation of Hg’ by two- and three-component model fly ashes composed of mixtures of: AlzOs, SiOz, FezOs, CuO, and CaO. Copper and iron oxides were the only two components that exhibited significant catalytic activity in the surface-mediated oxidation of Hg’. The reactivity of these two metals is hypothesized to be affected through the formation of a chlorinating agent (most probably Cl*) from gasphase HCI on the surface of metal oxides (the Deacon process reaction). Copper was much more effective in the oxidation of Hg’than iron, and its catalytic activity was less sensitive to the presence of oxidation inhibitors (SOz and water vapour). The presence of a small quantity of CuO (0.1% wt) in the model fly ash caused a 95% oxidation of Hg’ in the temperature range of 150 to 250°C. The same extent of Hg oxidation was obtained by adding 14% (wt) FezOx to the model fly ash. 02/00694 Molecular tracers for biomass burning emissions from species specific fuel sources Simoneit, B.R.T. et al. Meas. Toxic R&t. Air Pollut.. Proc. Spec. Conf,, 1998, I, 9-36. Biomass fuels from species specific vegetation of tropical, temperate and arctic climate regions were subjected to controlled burning, both under smoldering and flaming conditions. Coal samples were also burned for comparison purposes. Smoke particulate matter was sampled by high volume air filtration on precleaned quartz fibre filters. The filtered particles were extracted with dichloromethane and the crude extracts were methylated for separation by thin layer chromatography into hydrocarbon, carbonyl, carboxylic acid ester and polar fractions, then analysed by both conventional and high temperature gas chromatography (GC) and gas chromatography-mass spectrometry (GC-MS). The major organic components in smoke particles were straight chain aliphatic compounds from vegetation wax and terpenoids (biomarkers) from gum or resin. The major natural products altered by combustion included derivatives from phenolic (lignin) and monosaccharide (cellulose) biopolymers and oxygenated and aromatic products from diterpenoids and triterpenoids. Biomarkers present as minor components included triterpenols and phytosterols, both the natural and altered products, and unaltered high molecular weight wax esters. Polycyclic aromatic hydrocarbons (PAH) were also present, however, as minor constituents and oxy-PAH occurred at trace levels. Although the concentrations of organic compounds in smoke aerosols are highly variable and dependent on burn temperature, the biomarkers and their combustion alteration products are source specific. These molecular tracers may be utilized as indicators in the atmosphere for determining fuel type and source contributions from biomass burning. 02/00695 NO, chemistry and emissions - 1. heterogeneous reactions (NO + NO*) Svoboda, K. et al. NATO Sci. Ser., Ser. C, 2000, 547, 145-163. The review, with 49 references, focuses on the mechanism and reaction kinetics of fuel N conversion to NO in combustion of solid fuels (coal, peat, wood). The mechanism and kinetics of heterogeneous catalysed and gas-solid non-catalysed reactions of NO formation in solid fuel devolatilization and char combustion have been studied in terms of NO-precursor release (NH3 + HCN), precursor oxidation and decomposition. Destruction reactions (interactions and reduction reactions) of NO, mainly by char, CO and H, are very important for final emissions of NO in combustion. Application of heterogeneous mechanisms and kinetics of fuel-N-+NO formation and NO destruction is mainly in fluidized bed combustion, partly in pulverized coal combustion (where thermal NO formation may be significant). 02/00696 NO, chemistry and emissions - II. heterogeneous reactions (N20) Svoboda, K. et al. NATO Sci. Ser., Ser. C, 2000, 547, 165-182. A review, with 40 references, is given. NzO concentrations in the atmospheric increase at an estimated rate of 0.7-0.8 ppb/year. The combustion of solid fuels and waste at lower temperatures (750-900”) constitutes a significant source of NzO. During stages of a coal particle combustion (pyrolysis-devolatilization and char combustion) both volatile-N and char-N are mainly transformed to N + NO and partly to NzO. HCN was recognized as the main precursor for NzO in volatile combustion. Char-N conversion to NzO (through various mechanisms) is affected by in situ reduction of NzO by the C surface and CO. The temperature is a key parameter for NzO emissions in combustion. At
(pollution, health protection,
>lOOO”, NzO emissions are negligible. In practical combustion char and CaO are the most effective catalysts for the decomposition of NzO.
safety) systems thermal
Novel technologies of low-toxicity combustion at 02/00697 US coal power plants Kotler, V.R. Teploenergetika (Moscowl, 2000, 4, 72-75. (In Russian) A review, with six references. It was shown that a combination of threestage combustion and selective non-catalytic reduction of NO, decreased the nitrogen oxide emissions from pulverized-coal-fired boilers by two- to three-fold without the use of the expensive catalytic reactors. 02/00696 Nucleotide markers for environmental identification of sources of petroleum products and organic liquids Saluz, H.P., Braeuer, A. Ger. Offen. DE 19860,546 (Cl. GOlN33/26), 29 Jun 2000, Appl. 19,860,546, 23 Dee 1998. 5. (In German) An inexpensive and highly sensitive process is described for marking petroleum products or organic liquids, for identification of sources of environmental pollution and manufacturers responsible for pollution. Natural or synthetic organic liquids, e.g. petroleum products, coal tar fractions and solvents, are marked by mixing with specific lipophilic oligonucleotides, detectable by known optical methods. The lipophilic oligonucleotides can be isolated from the environment and identified by sequence analysis, 02/00699 Photochemical transformation of polycyclic aromatic hydrocarbons on solid particles Teinemaa, E., Kirso, U. Polycyclic Aromatomic compound, 1999, 14-15, 275-284. Photochemical transformation and adsorption of some polycyclic aromatic hydrocarbons, PAH, e.g. phenanthrene, anthracene and pyrene, on the different particulate matter: alumina, silica and oil shale fly ash were investigated. Fly ash from oil-shale thermal power plants is characterized by a small specific surface area and a low adsorption capacity in comparison to common adsorbents. The surface on which PAH were adsorbed have a strong effect on their decay. The phototransformation efficiency of the PAH studied was largest for silica, followed by alumina. PAH were more resistant to photochemical transformation on fly ash than on alumina and silica. Variation in decay rates between the different PAH on any given matrix was found to be significant. Phenanthrene was much less photochemically reactive than pyrene, and especially anthracene, on any particulate matter used in this study. Nonphotochemical degradation (autoxidation) of PAH on alumina, silica and fly ash was found to be negligible. Stability of carcinogenic pollutants adsorbed on fly ash may cause a significant public health concern. 02lOO700 Pollution to pollution Anon., Colourage, 2000, 47, (1) 41-42, 45. Environmental pollution is discussed, including and coal tar as a pollutant.
evolution
of coal gas
Potassium doped bimetallic alloy material for 02/00701 producing environment friendly clean energy Hussain, S.T., Atta, M.A. J. Nat. Sri. Math., 1998, 38, (1 & 2), 205-215. Carbon monoxide, a byproduct of the chemical process industries, is a deadly poisonous gas, if released into the atmosphere causes irreparable damages to the environment. A bimetallic catalyst system Ru:Mn doped with different concentration of potassium supported on a high surface area aluminium oxide support was prepared by coimpregnation method dispersed and reduced at 450°C under hydrogen flow using a closed reactor system at atmospheric pressure for the utilization of poisonous CO gas to produce environment friendly clean energy. Fischer-Tropsch catalyst when subjected to CO/hydrogenation gives unsaturated and saturated hydrocarbon products. The main purpose of this research work was two-fold. First, the powder catalyst when dispersed and reduced on a high surface area oxide support spreads on the surface of the system in different orientations and shapes. The particle size of the prepared catalyst ranges from 5.0 to 25.0 nm. The whole system forms a complicated mixture of numerous particles and hence becomes very complicated to study. The characterization of these randomly oriented particles having different sizes and shapes is a difficult job. This requires sensitive ultra high vacuum spectroscopic techniques like static secondary ion mass spectrometry, XPS, X-ray diffraction analysis and transmission electron microscopy. All these techniques used to characterize this complicated material before performing the synthesis reaction indicates the presence of two new materials on the surface, one Ru: MulRuO: MnO and the other Ru:Mn :K/RuO :MnO:KzO. Secondly, since Ru is a very good Fischer-Tropsch catalyst for the production aliphatic hydrocarbon products, our other aim was to find out whether if by surface restructuring through chemical treatment, we could alter the path if this CO/hydrogenation reaction to produce potentially important and Fuel and Energy Abstracts
January 2002
71
(pollution, health protection,
safety)
This study was focused at estimating the human health risk of the general and working population living in the region polluted by arsenic for more than 40 years, from combustion of coal with high arsenic content in the power plant. The exposure to arsenic from inhalation was under investigation. A study period of 40 years (1973-1993) was chosen. The study period was defined taking into account, besides the availability of data, the temporal patterns of the technology processes and the trends over time of environmental concentrations. The results from the arsenic risk assessment study were used for the evaluation of the health risk for different population groups in the polluted areas and for different professions of workers exposed to As in a power plant. The results are applicable for the evaluation of risk in real conditions, for health surveillance and for remedial changes and a potential suggestion on technology improvement. 02fOO665 High efficiency utilization of fossil fuel and environmental protection technology Sema, T., Makino, H. Kagaku Kogaku, 2000, 64, (4), 167-171. (In Japanese) A review, with six references, of the title subject, fossil fuel resources, pollution prevention in utilizing fossil fuels in power plants, and future trends of fossil fuel utilization. 02fOO666 Impact of erosion-transported overburden dump materials on water aualitv in Lake Cosouden evolved from a former open cast lignite mine south of leipzig, Germany Abel, A. er al. Environ. Geol. (Berlin), 2000, 39, (6), 683-688. Acidification is the most common water quality problem in lakes created from previous open cast lignite mines. Aeration of aquifers and dump materials from mining activities causes pyrite oxidation. Pyrite oxidation products are stored in pore water, minerals, and at the exchange complexes of aquifers and dump sediment. Rain fall runoff transports sediment on the dump slope into lakes. Elutriation of this sediment within lakes releases either acid-producing or acid-neutralizing agents. At a test site south of Leipzig, Germany, annual erosion rates were quantified by water erosion models (RUSLE, EROSION 2D, PEPP) and field measurements. They ranged from 300 to 900 tons/ ha. Hydrogen ion equivalence release or binding at the sediment elutriation was computed from laboratory analysis of pore water quality, ion exchange complex, and sediment mineral composition. Two of three investigated sediment contained 3 mmol (equivalence) acidity/ 100 g dry sediment and revealed saturation with respect to jarosite, jurbanite, and gypsum. In the third sediment, 6 mmol (equivalence) alkalenity/lOO g dry sediment was obtained. Annual net acidity influx was calculated to be ~0.5 million mol (equivalent) for the lake at the test side. 02/00667 Impact of sodium chloride on coal combustion emissions Liu, Y. er al. Xi’an Jiaotong Daxue Xuebao, 2000, 34, (5), 42-45, 58. (In Chinese) The effect of sodium chloride on the coal combustion emissions is investieated bv usine a thermoeravimetric analvser at different heating rates 00, 20’and 50 degrees-per min) from room temperature to 1000°C. The experimental data can be used to better understand the role of chlorides when coal and solid wastes are combusted together in boilers. The experimental results show that sodium chloride can reduce sulphur dioxide emission in coal combustion process and enhance desulphurization. 02/00666 Improved containment transport modelling for hypothetical accidents in fusion power plants Han, W.E., Karditsas, P.J. Fusion Engineering and Design, 2000, 51-52, 535-542. We report here improvements to a code, FUSCON, developed for the SEAFP-2 (Safety and Environmental Aspects of Fusion Power) study to model containment transport and release to the environment. The previous version of FUSCON did not include heat transfer to the wall, accounted for condensation for only a limited set of conditions, and hence placed restrictions on some of the containment parameters investigated. The improvements described involve modelling of postaccident convective transport in the containment system. This is a good basis for enhancement of the model to include mass transfer effects associated with condensation. Three-dimensional, computational-fluiddynamics, finite-element calculations have guided the derivation of a computationally economic model of convective containment transport. The efficiency of the model will ensure that FUSCON is still sufficiently fast-running to be used to study confinement system optimization and selection. 02/00669 degassing Bukhantsov, Russian) 70
Improvement A.I., Porubai,
of mining safety based on effective V.V.
Fuel and Energy Abstracts
Ugol’ Ukr.,
1999, 10, 42-50.
January 2002
(In
Based on the advantages and disadvantages of basic coal seam degassing methods, a combined pneumatic-hydraulic technology was developed for methane removal from coal stratum via the apertures bored from the ground surface. This method involves the hydrodynamic treatment of the stratum with a limited volume of liquid supplemented with inert substances, which increase the mass transfer of the liquid, thereby ensuring the opening of natural fracture systems oriented toward the aperture and the further development of these systems during air pumping into the stratum under different regimes with the possibilitv of using additional intensifvina effects. In experiments conducted in mines, the use of this method decreased the emissions of CH., into the mine drifts by 57-66%. 02/00690 Indoor coal combustion emissions, GSTMl and GSTTl genotypes? and lung cancer risk: a case-control study in Xuan Wer, China Lan, Q. et al. Cancer Epidemiol., Biomarkers Prev., 2000, 9, (6). 605608. Lung cancer mortality rates in Xuan Wei County, China are among the highest in the country and has been associated with exposure to indoor smoky coal emissions that contain high levels of polycyclic aromatic hvdrocarbons. This risk mav be modified bv variation in metabolic genes, including GSTMl, which encodes an enzyme known to detoxify polycyclic aromatic hydrocarbons. To study the relation between GST genotypes and lung cancer risk in Xuan Wei County, we analysed GSTMl and GSTTl genotypes in a population. A total of 122 lung cancer patients and 122 controls, individually matched by age, sex, and home fuel type, were studied. Compared to subjects who used cl30 tons smokv coal durine their lifetime. heavier users f>130 tons) had a 2.4-fold (95% confid&ce interval, ‘1.3-4.4) increasid risk of lung cancer. The GSTMl-null genotype was associated with a 2.3-fold (95% confidence interval, 1.3-4.2) increased risk of lung cancer. There was some evidence that smoky coal use was more strongly associated with lung cancer risk among GSTMI-null versus GSTMl-positive individuals. In contrast, the GSTTl genotype was not significantly associated with lung cancer risk. Data suggest that the GSTMI-null genotype may enhance susceptibility to air pollution from indoor coal combustion emissions. 02/00691 Liquid fuel additive for improved combustion efficiencv and reduced noxious emissions Horio, T. ;I al. Faming Zhuanli Shenqing Gongkai Shuomingshu CN 1,210,135 (Cl. ClOL1/22), 10 Mar 1999, Appl. 97,114,244, 29 Aug 1997. 6. (In Chinese) The liquid fuel additive is composed of gasoline, diesel oil or kerosene 100 L, succinimide 0.02-0.06, amine oxide 3-6, synthetic ester 0.5-1.5, Paradyne 0.5-4, dialkyl diphenylamines 0.1-0.5, tolyl di-Ph phosphates 0.02-0.05, methylphenyldiamine 0.1-0.3, zinc dialkyldithiosulfate 0.050.1, and N,N’-bis(salicylidene)-1,2-diaminobenzene 0.3-0.8 g. 02/00692 Means to decrease nitrogen oxides emissions during firing of coke furnaces Pyrikov, A.N., Chernyshev, V.N. Sral’, 1999, 12, 81-85. (In Russian) The means for controlling NO, emissions from coke ovens are discussed. Flue gas recirculation, staged air firing, and catalytic reduction of nitrogen oxides are cited as effective. 02/00693 Mercury control research: effects of fly ash and flue gas parameters on mercury speciation Lee, C.W. et al. Annu. Waste-to-Energy Co@.. Proc. Spec. Conf., 6th, 1998, 221-238. In flue gas from combustion systems, mercury (Hg) is typically in the vapour phase at flue gas cleaning temperatures, and the control of Hg emissions is dependent on the specific Hg compounds that are present (soeciation) and the tvue of air oollution devices emoloved. In drv and se-mi-dry scrubbing sysiems, the’ control of Hg emiss’ions is dependent on the sorption of Hg by particulate matter (PM) which can be subsequently collected in a PM control device. In wet scrubbing systems, the principal mechanisms of control are the removal of sol. forms of Hg and the collection of particle-bound Hg. At combustion temperatures, Hg is btlieved to be predominantly in the form of elemental mercury (Hg ). As the flue #as is cooled, thermochemical equilibrium calculations indicate the Hg IS converted primarily to ionic mercury (Hg++) in the form of mercuric oxide (HgO) or mercuric chloride (HgClz). Hg” is insoluble in water, but HgO has a low solubility while HgClz is highly soluble. The oxidation of Hg” to an ionic form depends on the temperature, the time-temperature profile, the flue gas composition, the reaction kinetics, and the presence of solids that may catalyse reactions. Bench-scale experiments were conducted to study the effects of flue gas and fly ash parameters on the oxidation of Hg” in simulated flue gases containing hydrogen chloride (HCl). Gas-phase studies indicated that the in-flieht oostcombustion oxidation‘of Hg” in the presence of HCl is very slow’ and proceeds at measurable rates only at high temperatures (> 700°C) and high HCl concentrations (>200 ppm). The presence of sulphur dioxide
15 Environment (SO*) and water vapour in the simulated flue gas significantly inhibited the gas-phase oxidation of Hga. On the other hand, preliminary investigation indicated that the gas-phase reaction of Hg’with chlorine (Cl,) is fast. At 40°C and in the presence of 50 ppm Clz, 100% of the input Hg’ was oxidized to HgClz in less than 2 s, indicating that Clz is a much more active chlorinating agent than HCI. The effects of fly ash composition were investigated using a fixed-bed reactor containing different model fly ashes (simulated fly ash) consisting of mixtures of some major components found in coal and municipal waste combustor (MWC) fly ashes. Work to date has focused on the potential catalytic oxidation of Hg’ by two- and three-component model fly ashes composed of mixtures of: AlzOs, SiOz, FezOs, CuO, and CaO. Copper and iron oxides were the only two components that exhibited significant catalytic activity in the surface-mediated oxidation of Hg’. The reactivity of these two metals is hypothesized to be affected through the formation of a chlorinating agent (most probably Cl*) from gasphase HCI on the surface of metal oxides (the Deacon process reaction). Copper was much more effective in the oxidation of Hg’than iron, and its catalytic activity was less sensitive to the presence of oxidation inhibitors (SOz and water vapour). The presence of a small quantity of CuO (0.1% wt) in the model fly ash caused a 95% oxidation of Hg’ in the temperature range of 150 to 250°C. The same extent of Hg oxidation was obtained by adding 14% (wt) FezOx to the model fly ash. 02/00694 Molecular tracers for biomass burning emissions from species specific fuel sources Simoneit, B.R.T. et al. Meas. Toxic R&t. Air Pollut.. Proc. Spec. Conf,, 1998, I, 9-36. Biomass fuels from species specific vegetation of tropical, temperate and arctic climate regions were subjected to controlled burning, both under smoldering and flaming conditions. Coal samples were also burned for comparison purposes. Smoke particulate matter was sampled by high volume air filtration on precleaned quartz fibre filters. The filtered particles were extracted with dichloromethane and the crude extracts were methylated for separation by thin layer chromatography into hydrocarbon, carbonyl, carboxylic acid ester and polar fractions, then analysed by both conventional and high temperature gas chromatography (GC) and gas chromatography-mass spectrometry (GC-MS). The major organic components in smoke particles were straight chain aliphatic compounds from vegetation wax and terpenoids (biomarkers) from gum or resin. The major natural products altered by combustion included derivatives from phenolic (lignin) and monosaccharide (cellulose) biopolymers and oxygenated and aromatic products from diterpenoids and triterpenoids. Biomarkers present as minor components included triterpenols and phytosterols, both the natural and altered products, and unaltered high molecular weight wax esters. Polycyclic aromatic hydrocarbons (PAH) were also present, however, as minor constituents and oxy-PAH occurred at trace levels. Although the concentrations of organic compounds in smoke aerosols are highly variable and dependent on burn temperature, the biomarkers and their combustion alteration products are source specific. These molecular tracers may be utilized as indicators in the atmosphere for determining fuel type and source contributions from biomass burning. 02/00695 NO, chemistry and emissions - 1. heterogeneous reactions (NO + NO*) Svoboda, K. et al. NATO Sci. Ser., Ser. C, 2000, 547, 145-163. The review, with 49 references, focuses on the mechanism and reaction kinetics of fuel N conversion to NO in combustion of solid fuels (coal, peat, wood). The mechanism and kinetics of heterogeneous catalysed and gas-solid non-catalysed reactions of NO formation in solid fuel devolatilization and char combustion have been studied in terms of NO-precursor release (NH3 + HCN), precursor oxidation and decomposition. Destruction reactions (interactions and reduction reactions) of NO, mainly by char, CO and H, are very important for final emissions of NO in combustion. Application of heterogeneous mechanisms and kinetics of fuel-N-+NO formation and NO destruction is mainly in fluidized bed combustion, partly in pulverized coal combustion (where thermal NO formation may be significant). 02/00696 NO, chemistry and emissions - II. heterogeneous reactions (N20) Svoboda, K. et al. NATO Sci. Ser., Ser. C, 2000, 547, 165-182. A review, with 40 references, is given. NzO concentrations in the atmospheric increase at an estimated rate of 0.7-0.8 ppb/year. The combustion of solid fuels and waste at lower temperatures (750-900”) constitutes a significant source of NzO. During stages of a coal particle combustion (pyrolysis-devolatilization and char combustion) both volatile-N and char-N are mainly transformed to N + NO and partly to NzO. HCN was recognized as the main precursor for NzO in volatile combustion. Char-N conversion to NzO (through various mechanisms) is affected by in situ reduction of NzO by the C surface and CO. The temperature is a key parameter for NzO emissions in combustion. At
(pollution, health protection,
>lOOO”, NzO emissions are negligible. In practical combustion char and CaO are the most effective catalysts for the decomposition of NzO.
safety) systems thermal
Novel technologies of low-toxicity combustion at 02/00697 US coal power plants Kotler, V.R. Teploenergetika (Moscowl, 2000, 4, 72-75. (In Russian) A review, with six references. It was shown that a combination of threestage combustion and selective non-catalytic reduction of NO, decreased the nitrogen oxide emissions from pulverized-coal-fired boilers by two- to three-fold without the use of the expensive catalytic reactors. 02/00696 Nucleotide markers for environmental identification of sources of petroleum products and organic liquids Saluz, H.P., Braeuer, A. Ger. Offen. DE 19860,546 (Cl. GOlN33/26), 29 Jun 2000, Appl. 19,860,546, 23 Dee 1998. 5. (In German) An inexpensive and highly sensitive process is described for marking petroleum products or organic liquids, for identification of sources of environmental pollution and manufacturers responsible for pollution. Natural or synthetic organic liquids, e.g. petroleum products, coal tar fractions and solvents, are marked by mixing with specific lipophilic oligonucleotides, detectable by known optical methods. The lipophilic oligonucleotides can be isolated from the environment and identified by sequence analysis, 02/00699 Photochemical transformation of polycyclic aromatic hydrocarbons on solid particles Teinemaa, E., Kirso, U. Polycyclic Aromatomic compound, 1999, 14-15, 275-284. Photochemical transformation and adsorption of some polycyclic aromatic hydrocarbons, PAH, e.g. phenanthrene, anthracene and pyrene, on the different particulate matter: alumina, silica and oil shale fly ash were investigated. Fly ash from oil-shale thermal power plants is characterized by a small specific surface area and a low adsorption capacity in comparison to common adsorbents. The surface on which PAH were adsorbed have a strong effect on their decay. The phototransformation efficiency of the PAH studied was largest for silica, followed by alumina. PAH were more resistant to photochemical transformation on fly ash than on alumina and silica. Variation in decay rates between the different PAH on any given matrix was found to be significant. Phenanthrene was much less photochemically reactive than pyrene, and especially anthracene, on any particulate matter used in this study. Nonphotochemical degradation (autoxidation) of PAH on alumina, silica and fly ash was found to be negligible. Stability of carcinogenic pollutants adsorbed on fly ash may cause a significant public health concern. 02lOO700 Pollution to pollution Anon., Colourage, 2000, 47, (1) 41-42, 45. Environmental pollution is discussed, including and coal tar as a pollutant.
evolution
of coal gas
Potassium doped bimetallic alloy material for 02/00701 producing environment friendly clean energy Hussain, S.T., Atta, M.A. J. Nat. Sri. Math., 1998, 38, (1 & 2), 205-215. Carbon monoxide, a byproduct of the chemical process industries, is a deadly poisonous gas, if released into the atmosphere causes irreparable damages to the environment. A bimetallic catalyst system Ru:Mn doped with different concentration of potassium supported on a high surface area aluminium oxide support was prepared by coimpregnation method dispersed and reduced at 450°C under hydrogen flow using a closed reactor system at atmospheric pressure for the utilization of poisonous CO gas to produce environment friendly clean energy. Fischer-Tropsch catalyst when subjected to CO/hydrogenation gives unsaturated and saturated hydrocarbon products. The main purpose of this research work was two-fold. First, the powder catalyst when dispersed and reduced on a high surface area oxide support spreads on the surface of the system in different orientations and shapes. The particle size of the prepared catalyst ranges from 5.0 to 25.0 nm. The whole system forms a complicated mixture of numerous particles and hence becomes very complicated to study. The characterization of these randomly oriented particles having different sizes and shapes is a difficult job. This requires sensitive ultra high vacuum spectroscopic techniques like static secondary ion mass spectrometry, XPS, X-ray diffraction analysis and transmission electron microscopy. All these techniques used to characterize this complicated material before performing the synthesis reaction indicates the presence of two new materials on the surface, one Ru: MulRuO: MnO and the other Ru:Mn :K/RuO :MnO:KzO. Secondly, since Ru is a very good Fischer-Tropsch catalyst for the production aliphatic hydrocarbon products, our other aim was to find out whether if by surface restructuring through chemical treatment, we could alter the path if this CO/hydrogenation reaction to produce potentially important and Fuel and Energy Abstracts
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