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Specific chimney emissions and biofuel characteristics of softwood pellets for residential heating in Sweden
75 Environment
(pollution, health protection,
safety)
03/00908 Safety implications of CLiFF liquid metal first walls Merrill, B. J. ct LII.Fusion E~,qirw~~~i~zg untl Dc\ign. 2002, 6% 64, 2X5 293. In this article some of the safety issues were explored associated with the Advanced Power Extraction (APEX) liquid metal first wall (FW) concept called the Convective Liquid Flow First Wall (CLIFF) design. In particular, the chemical reactivity of and the site boundary dose were examined from three liquid metals being proposed for the CLiFF FW during a worst-case confinement-boundary-bypass accident. The liquid metals considered were: lithium, tin, and gallium. The accident analyscd was a loss-of-vacuum accident (LOVA), during which air entered the CLiFF vacuum vessel (VV) from an adjoining room through a connecting diagnostic port or plasma-heating duct. The resulting lithium fire was analysed and the energy released from thi< fire was found to be manageable for the CLiFF blanket design presently under consideration. The estimated dose at the site boundary is less than the no-evacuation limit of 10 mSv for ground level release\ if plant isolation occurs within several hours.
03/00909 Scenario-model-parameter: a new method of cumulative risk uncertainty analysis Moschandreas, D. J. and Karuchit, S. .Fnv~ronn~~~~~t /rltc,,./rc/tiorlrr/. 2001. ‘8, (4). 247 261. The recently developed concepts of aggregate risk and cumulative risk rectify two limitations associated with the classical risk assessment paradigm established in the early 1980s. Aggregate exposure denote\ the amount of O/IC pollutant available at the biological exchange boundaries from multiple routca of exposure. Cumulative risk asw\+ ment is defined as an assessment of rijk from the accumulation 01‘‘I common toxic effect from all routes of exposure to /llu/tip/c chemical\ sharing a common mechanism of toxicity. Thu\. cumulative risk constitute\ an improvement over the cla\,icul rl\k paradigm, which treats exposures from multiple routes ;15 indepcndcnt events assoclatcd with each specific route. Risk assessors formulate complex model\ and identify many realistic scenarios of exposure that enable them to cstimatc risks from exposures to multiple pollutant\ and multiple routes. The increase in complexity of the risk assessment procc\j I\ likely to increase risk uncertainty. Despite evidence that scenario and tnodcl uncertainty contribute to the overall uncertainty of cumulatt\e risk estimates. present uncertainty analysi\ of risk estimate\ account\ only for parameter uncertainty and excludes model and sccnarlo uncertainties. This paper provide\ ;I \ynopsl\ of the risk asse\smcnt evolution and associated uncertainty analysis methods. This c\olution leads to the concept of the scenario~model parameter (SMP) cutnulativc risk uncertainty analysis method. The SMP uncertainty analysis associated with is ;I multiple step procedure that asaesseh uncertainty the use of judicio&ly .stj/rc/c>d $ccnario\ and models of cxpo\urc ,III~ risk. Ultimately. the SMP uncertainty analysis method compare\ rish uncertainty estimates determined using all three source\ of uncertainty \+ith conventional risk uncertatnty cctimates obtained using only tho parameter source. An example of applying the SMP uncertaint! analysis to cumulative ri\k estimates f‘t-om exposures to two pesticide\ and model \ourccs incrca\e\ indlcatcs that inclusion of scenario uncertainty of risk estimates relati\c to those estimated using onI> m:ignitudc may affect the parameter source. Change\ tn unccrtninty decision\ made by risk managers
03/00910 Sediment-dissolved organic matter equilibrium partitioning of pentachlorophenol. The role of humic matter Paaso, N. rt ~1.Environment Intrrnational, 2002. 28, (3). 173 -183. The dissolved humic matter (HM) has an essential influence on the release of the bound pentachlorophenol (PCP) from the solid sediment. It was studied how the increase of the dissolved HM concentration affects the equilibrium partitioning of PCP between the solid sediment matter and dissolved HM. The lake sedimentary and dissolved HM were isolated and their structural compositions were compared with elemental analyses, solid-sate 13C NMR spectroscopy and degradative analyses by pyrolysis-GC/MS. At the beginning of the equilibrium experiment, the PCP contaminant (200 p g 1-l) was added into the water-sediment slurry system having an initial dissolved HM concentration. After 35 days, the system has reached an equilibrium and 75.5% of PCP was bound to the total solid sediment, 1.5% to dissolved HM and 23.0% remained free in water. The dissolved HM content was increased by 150% and, at the second equilibrium state after 91 days, only 63.8% of PCP was bound to the total sediment, and even 6.5% to the dissolved HM and 29.7% was free. The structural analyses indicated that the contents of aliphatics, aromatics and carboxylic carbons are lower in sediment than in dissolved HM, the content of carbohydrates in turn is higher in sediment than in dissolved HM, as well as that of different protein descriptors. The closely related partition coefficients for the sediment and dissolved HM, however, implied that the structural dissimilarity of these sorbents does not play so strong roles in the binding affinity of PCP as it would be postulated.
184
Fuel and Energy Abstracts
May 2003
The relatively great sorption coefficient of the minor colloid-like particle fraction in water implied its special but quantitatively quite immaterial roles in the partitioning cycle of PCP.
03/00911 Specific chimney emissions and biofuel characteristics of softwood pellets for residential heating in Sweden Olsson, M. ct 01.H~o~7c/s.\ rr17tl Bioozcr,q~~. 2003, 24, (1 ). 5 I 57 Softwood oellets arc mainlv oroduccd from sawdust and to some extent from wooi shavings. The &&sture content is typically less than half of‘ that in firewood. The present annual residential use in Sweden for pellet burners in boilers and for pellet stoves amounts to more than 100000 tonnes and i\ increasing rapidly. The total annual production capacity at the more than 20 units exceeds one million tonnes. and permits continued rapid replacement of firewood and petroleum oil for residential heating. With the purpose of characterizing emissions to air, chimney smoke was sampled, and specific compounds wcrc asscsscd by gas chromatograph!: and mass spcctrometry. Benzcnc was the predominant aromatic compound in emissions from pellet burner\. The smoke trom stoves contained mcthoxyphenols with antioxidant properties and lower proportions of aromatic hydrocarbons. Observed diffcrcnces in emissions from specific burning appliances are of interest with regard to both health hazards and regulation of emissions. Consideration of ecological aspects and pollution hazards indicates that wood ncllets should be used orimarilv i for residential heatinp. wherea\ controlled large-scale comb;stion is preferable for most othgr types of hioma5s. . waste. , L
03/00912 Sr and Pb isotopes as environmental indicators in environmental studies Charalampides, G. and Manoliadic, 0. E~?\*ir.orlnlrrr/ f,ltc,/./rrrtro/r~cl. 2002.2x. (3), 147 1st An environmental indicator is a numerical or a descriptive categorization of environmental data with the primary purpose of assessing the affected environment. In these studies, two characteristic isotopes, namely Sr and Ph, were assessed of their ability to describe the affected environment in environmental studies by detecting trends of pollution over short as well as long time periods and by identifying sources of contamination. The ability of environmental indicators to serve a\ clement\ in summarizing the situation of the affected environment is discussed. An illustrative example is prcscnted where lead isotopes are used to understand the source of pollution in Kozani, a small rural area in Greece. Conclusions are derived in terms of the source of the pollution in the specific arca.
03/00913 Study on measuring method of mercury in flue gas and its application for coal-fired test plant Kikkawa, H. and Nakamoto, T. Procwrlings of t/1(, tutcrurrtiorltrl TcchtlicuI C’orlfc~rcww OH Cod Utilizotror~ & Furl LYjb\tcms, 2002. I. (27). I 13 124. (In Japanese) The chemical species of mercury i:, considered to influence the behaviour of mercury in a coal-fired power plant. In order to evaluate the behaviour of mercury in pollution control devices such as selective catalytic reduction (SCR) for NOx control. electrostatic precipitators (ESPs) and wet limestone-gypsum flue gas desulfurization (FGD) system, it is thcreforc necessary to measure mercury concentration of each species in flue gas separate In a laboratory, carrier gas containing vupour of elemental mercury or mercury chlorides was employed to establish appropriate gas sampling and analysis methods for detecting mercury species. As the result of our studies, combination of butter solution and H2SOJ-KMn04 solution or mercury collector tubes is recommended. Based on thcsc fundamental studies on sampling and analysis methods of mercury, mercury behaviour in a coal-fired plant was investigated at a pilot-scale test facility. Four types of coals were evaluated in the pilot-scale test facility, equipped with pollution control devices such as ESPs, SCR for NOx control, and wet FGD system (spray scrubber). Flue gas temperatures at the inlet of ESPs were controlled constant between 90-150°C by gas-gas heaters and a gas cooler. Coal combustion rates were 130-150 kg/h depending on coal types. The main target of this study was to detect mass balances oi mcrcurq. The amount of mercury emitted from the furnace, which was calculated from the gas flow rate and the mercury concentration therein. was almost equal to the value that detected from coal feed rate and coal analysis, hence it is understood that proposed measuring method i\ accurate. As the gas cooled after combustion, the percentage of elemental mercury decreased up to the inlet or outlet of ESPs and increased again after ESPs or FGD system because oxidized and particulate mercury in the flue gas was removed more effectively in ESPs and FGD system than elemental mercury. It has been also confirmed that the percentage of elemental mercury at a certain gas temperature decreased with Cl concentration in coal.
(pollution, health protection,
safety)
03/00908 Safety implications of CLiFF liquid metal first walls Merrill, B. J. ct LII.Fusion E~,qirw~~~i~zg untl Dc\ign. 2002, 6% 64, 2X5 293. In this article some of the safety issues were explored associated with the Advanced Power Extraction (APEX) liquid metal first wall (FW) concept called the Convective Liquid Flow First Wall (CLIFF) design. In particular, the chemical reactivity of and the site boundary dose were examined from three liquid metals being proposed for the CLiFF FW during a worst-case confinement-boundary-bypass accident. The liquid metals considered were: lithium, tin, and gallium. The accident analyscd was a loss-of-vacuum accident (LOVA), during which air entered the CLiFF vacuum vessel (VV) from an adjoining room through a connecting diagnostic port or plasma-heating duct. The resulting lithium fire was analysed and the energy released from thi< fire was found to be manageable for the CLiFF blanket design presently under consideration. The estimated dose at the site boundary is less than the no-evacuation limit of 10 mSv for ground level release\ if plant isolation occurs within several hours.
03/00909 Scenario-model-parameter: a new method of cumulative risk uncertainty analysis Moschandreas, D. J. and Karuchit, S. .Fnv~ronn~~~~~t /rltc,,./rc/tiorlrr/. 2001. ‘8, (4). 247 261. The recently developed concepts of aggregate risk and cumulative risk rectify two limitations associated with the classical risk assessment paradigm established in the early 1980s. Aggregate exposure denote\ the amount of O/IC pollutant available at the biological exchange boundaries from multiple routca of exposure. Cumulative risk asw\+ ment is defined as an assessment of rijk from the accumulation 01‘‘I common toxic effect from all routes of exposure to /llu/tip/c chemical\ sharing a common mechanism of toxicity. Thu\. cumulative risk constitute\ an improvement over the cla\,icul rl\k paradigm, which treats exposures from multiple routes ;15 indepcndcnt events assoclatcd with each specific route. Risk assessors formulate complex model\ and identify many realistic scenarios of exposure that enable them to cstimatc risks from exposures to multiple pollutant\ and multiple routes. The increase in complexity of the risk assessment procc\j I\ likely to increase risk uncertainty. Despite evidence that scenario and tnodcl uncertainty contribute to the overall uncertainty of cumulatt\e risk estimates. present uncertainty analysi\ of risk estimate\ account\ only for parameter uncertainty and excludes model and sccnarlo uncertainties. This paper provide\ ;I \ynopsl\ of the risk asse\smcnt evolution and associated uncertainty analysis methods. This c\olution leads to the concept of the scenario~model parameter (SMP) cutnulativc risk uncertainty analysis method. The SMP uncertainty analysis associated with is ;I multiple step procedure that asaesseh uncertainty the use of judicio&ly .stj/rc/c>d $ccnario\ and models of cxpo\urc ,III~ risk. Ultimately. the SMP uncertainty analysis method compare\ rish uncertainty estimates determined using all three source\ of uncertainty \+ith conventional risk uncertatnty cctimates obtained using only tho parameter source. An example of applying the SMP uncertaint! analysis to cumulative ri\k estimates f‘t-om exposures to two pesticide\ and model \ourccs incrca\e\ indlcatcs that inclusion of scenario uncertainty of risk estimates relati\c to those estimated using onI> m:ignitudc may affect the parameter source. Change\ tn unccrtninty decision\ made by risk managers
03/00910 Sediment-dissolved organic matter equilibrium partitioning of pentachlorophenol. The role of humic matter Paaso, N. rt ~1.Environment Intrrnational, 2002. 28, (3). 173 -183. The dissolved humic matter (HM) has an essential influence on the release of the bound pentachlorophenol (PCP) from the solid sediment. It was studied how the increase of the dissolved HM concentration affects the equilibrium partitioning of PCP between the solid sediment matter and dissolved HM. The lake sedimentary and dissolved HM were isolated and their structural compositions were compared with elemental analyses, solid-sate 13C NMR spectroscopy and degradative analyses by pyrolysis-GC/MS. At the beginning of the equilibrium experiment, the PCP contaminant (200 p g 1-l) was added into the water-sediment slurry system having an initial dissolved HM concentration. After 35 days, the system has reached an equilibrium and 75.5% of PCP was bound to the total solid sediment, 1.5% to dissolved HM and 23.0% remained free in water. The dissolved HM content was increased by 150% and, at the second equilibrium state after 91 days, only 63.8% of PCP was bound to the total sediment, and even 6.5% to the dissolved HM and 29.7% was free. The structural analyses indicated that the contents of aliphatics, aromatics and carboxylic carbons are lower in sediment than in dissolved HM, the content of carbohydrates in turn is higher in sediment than in dissolved HM, as well as that of different protein descriptors. The closely related partition coefficients for the sediment and dissolved HM, however, implied that the structural dissimilarity of these sorbents does not play so strong roles in the binding affinity of PCP as it would be postulated.
184
Fuel and Energy Abstracts
May 2003
The relatively great sorption coefficient of the minor colloid-like particle fraction in water implied its special but quantitatively quite immaterial roles in the partitioning cycle of PCP.
03/00911 Specific chimney emissions and biofuel characteristics of softwood pellets for residential heating in Sweden Olsson, M. ct 01.H~o~7c/s.\ rr17tl Bioozcr,q~~. 2003, 24, (1 ). 5 I 57 Softwood oellets arc mainlv oroduccd from sawdust and to some extent from wooi shavings. The &&sture content is typically less than half of‘ that in firewood. The present annual residential use in Sweden for pellet burners in boilers and for pellet stoves amounts to more than 100000 tonnes and i\ increasing rapidly. The total annual production capacity at the more than 20 units exceeds one million tonnes. and permits continued rapid replacement of firewood and petroleum oil for residential heating. With the purpose of characterizing emissions to air, chimney smoke was sampled, and specific compounds wcrc asscsscd by gas chromatograph!: and mass spcctrometry. Benzcnc was the predominant aromatic compound in emissions from pellet burner\. The smoke trom stoves contained mcthoxyphenols with antioxidant properties and lower proportions of aromatic hydrocarbons. Observed diffcrcnces in emissions from specific burning appliances are of interest with regard to both health hazards and regulation of emissions. Consideration of ecological aspects and pollution hazards indicates that wood ncllets should be used orimarilv i for residential heatinp. wherea\ controlled large-scale comb;stion is preferable for most othgr types of hioma5s. . waste. , L
03/00912 Sr and Pb isotopes as environmental indicators in environmental studies Charalampides, G. and Manoliadic, 0. E~?\*ir.orlnlrrr/ f,ltc,/./rrrtro/r~cl. 2002.2x. (3), 147 1st An environmental indicator is a numerical or a descriptive categorization of environmental data with the primary purpose of assessing the affected environment. In these studies, two characteristic isotopes, namely Sr and Ph, were assessed of their ability to describe the affected environment in environmental studies by detecting trends of pollution over short as well as long time periods and by identifying sources of contamination. The ability of environmental indicators to serve a\ clement\ in summarizing the situation of the affected environment is discussed. An illustrative example is prcscnted where lead isotopes are used to understand the source of pollution in Kozani, a small rural area in Greece. Conclusions are derived in terms of the source of the pollution in the specific arca.
03/00913 Study on measuring method of mercury in flue gas and its application for coal-fired test plant Kikkawa, H. and Nakamoto, T. Procwrlings of t/1(, tutcrurrtiorltrl TcchtlicuI C’orlfc~rcww OH Cod Utilizotror~ & Furl LYjb\tcms, 2002. I. (27). I 13 124. (In Japanese) The chemical species of mercury i:, considered to influence the behaviour of mercury in a coal-fired power plant. In order to evaluate the behaviour of mercury in pollution control devices such as selective catalytic reduction (SCR) for NOx control. electrostatic precipitators (ESPs) and wet limestone-gypsum flue gas desulfurization (FGD) system, it is thcreforc necessary to measure mercury concentration of each species in flue gas separate In a laboratory, carrier gas containing vupour of elemental mercury or mercury chlorides was employed to establish appropriate gas sampling and analysis methods for detecting mercury species. As the result of our studies, combination of butter solution and H2SOJ-KMn04 solution or mercury collector tubes is recommended. Based on thcsc fundamental studies on sampling and analysis methods of mercury, mercury behaviour in a coal-fired plant was investigated at a pilot-scale test facility. Four types of coals were evaluated in the pilot-scale test facility, equipped with pollution control devices such as ESPs, SCR for NOx control, and wet FGD system (spray scrubber). Flue gas temperatures at the inlet of ESPs were controlled constant between 90-150°C by gas-gas heaters and a gas cooler. Coal combustion rates were 130-150 kg/h depending on coal types. The main target of this study was to detect mass balances oi mcrcurq. The amount of mercury emitted from the furnace, which was calculated from the gas flow rate and the mercury concentration therein. was almost equal to the value that detected from coal feed rate and coal analysis, hence it is understood that proposed measuring method i\ accurate. As the gas cooled after combustion, the percentage of elemental mercury decreased up to the inlet or outlet of ESPs and increased again after ESPs or FGD system because oxidized and particulate mercury in the flue gas was removed more effectively in ESPs and FGD system than elemental mercury. It has been also confirmed that the percentage of elemental mercury at a certain gas temperature decreased with Cl concentration in coal.