Emission from burning coals is one of the major sources of the airborne particles in China.We carried out a study on the rare earth elements(REEs)in the inhalable particulate matter(PM10)emitted from burning coals and...Emission from burning coals is one of the major sources of the airborne particles in China.We carried out a study on the rare earth elements(REEs)in the inhalable particulate matter(PM10)emitted from burning coals and soil-coal honeycomb briquettes with different volatile contents and ash yields in a combustion-dilution system.Gravimetric analysis indicates that the equivalent mass concentration of the PM10 emitted from burning the coals is higher than that emitted from burning the briquettes.The ICP-MS analysis indicates that the contents of total REEs in the coal-burning PM10 are lower than those in the briquetteburning PM10.In addition,the contents of the light rare earth elements(LREEs)are higher than those of the heavy rare earth elements(HREEs)in the PM10 emitted from burning the coals and briquettes,demonstrating that the REEs in both the coal-burning and briquetteburning PM10 are dominated by LREEs.The higher contents of total REEs and LREEs in the coal-burning PM10 are associated with the higher ash yields and lower volatile contents in the raw coals.A comparative analysis indicates that the La/Sm ratios in the PM10 emitted from burning the coals and briquettes,being lower than 2,are lower than those in the particles from gasoline-powered vehicle emission.展开更多
The mechanisms of sulfur capturing during coal briquette combustion was discussed. Various factors affecting sulfur removal efficiency have been studied. Characterization of the slag left after combustion has been ca...The mechanisms of sulfur capturing during coal briquette combustion was discussed. Various factors affecting sulfur removal efficiency have been studied. Characterization of the slag left after combustion has been carried out by using X ray diffraction (XRD), Messbauer spectroscopy (MS), scanning electron microscopy (SEM), energy dispersion X ray analysis (EDAX), and electron spectroscopy for chemical analysis (ESCA). No other sulfur containing species besides CaSO 4 was found. Small amount of CaFe 3(SiO 4) 2OH, some complexes of CaO SiO 2 Fe 2O 3 and vitreous iron oxides were identified on the surface of CaSO 4 grains. This might explain the mechanism of sulfur fixation during coal briquettes combustion.展开更多
SHANXI Province, China’s key energy and heavy chemical industry base, boasts rich coal resources. Apart from fulfilling domestic supply requirements, and exporting to European and Asian countries, under the guidance ...SHANXI Province, China’s key energy and heavy chemical industry base, boasts rich coal resources. Apart from fulfilling domestic supply requirements, and exporting to European and Asian countries, under the guidance of the provincial Party Committee and provincial government, Shanxi also attaches importance to highly processed coal products.Bestowed generously with nature’s bounty, Lucheng City, in southeastern Shanxi, has over展开更多
The extensive use of traditional cooking and heating stoves to meet domestic requirements creates a serious problem of indoor and outdoor air pollution.This study reports the impacts of two fuel feeding methods-front-...The extensive use of traditional cooking and heating stoves to meet domestic requirements creates a serious problem of indoor and outdoor air pollution.This study reports the impacts of two fuel feeding methods-front-loading and top-loading on the thermal and emissions performance of a modern coal-fired water-heating and cooking stove using a contextual test sequence that replicates typical patterns of domestic use.Known as a low-pressure boiler,when this stove was fueled with raw coal,the findings indicate that front-loading the fuel,which devolatilizes the new fuel gradually,produced consistently higher space heating efficiency and lower emission factors than top-loading the same stove,which devolatilizes new fuel all at once.Comparing the performance at both high and low power gave the similar results:front-loading with raw coal produced consistently better results than top-loading.The average water heating efficiency when front-loading was(58.6±2.3)%and(53.4±1.8)%for top-loading.Over the sixteen-hour test sequence,front-loading produced 22%lower emissions of PM2.5(3.9±0.6)mg/MJNET than top-loading(4.7±0.9)mg/MJNET.The same pattern was observed for carbon monoxide and the CO/CO2 ratio.CO was reduced from(5.0±0.4)g/MJNET to(4.1±0.5)g/MJNET.The combustion efficiency(CO/CO2 ratio)improved from(8.2±0.8)%to(6.6±0.6)%.Briquetted semi-coked coal briquettes are promoted as a raw coal substitute,and the tests were replicated using this fuel.Again,the same pattern of improved performance was observed.Front loading produced 3.5%higher heating efficiency,10%lower CO and a 0.9%lower CO/CO2 ratio.It is concluded that,compared with top loading,the manufacturers recommended front-loading refueling behavior delivered better thermal,emissions and combustion performance under all test conditions with those two fuels.展开更多
基金supported by the Projects of International Cooperation and Exchanges NSFC(No.41571130031)the National Basic Research Program of China(No.2013CB228503)the Yueqi Scholar Fund of China University of Mining and Technology(Beijing)。
文摘Emission from burning coals is one of the major sources of the airborne particles in China.We carried out a study on the rare earth elements(REEs)in the inhalable particulate matter(PM10)emitted from burning coals and soil-coal honeycomb briquettes with different volatile contents and ash yields in a combustion-dilution system.Gravimetric analysis indicates that the equivalent mass concentration of the PM10 emitted from burning the coals is higher than that emitted from burning the briquettes.The ICP-MS analysis indicates that the contents of total REEs in the coal-burning PM10 are lower than those in the briquetteburning PM10.In addition,the contents of the light rare earth elements(LREEs)are higher than those of the heavy rare earth elements(HREEs)in the PM10 emitted from burning the coals and briquettes,demonstrating that the REEs in both the coal-burning and briquetteburning PM10 are dominated by LREEs.The higher contents of total REEs and LREEs in the coal-burning PM10 are associated with the higher ash yields and lower volatile contents in the raw coals.A comparative analysis indicates that the La/Sm ratios in the PM10 emitted from burning the coals and briquettes,being lower than 2,are lower than those in the particles from gasoline-powered vehicle emission.
文摘The mechanisms of sulfur capturing during coal briquette combustion was discussed. Various factors affecting sulfur removal efficiency have been studied. Characterization of the slag left after combustion has been carried out by using X ray diffraction (XRD), Messbauer spectroscopy (MS), scanning electron microscopy (SEM), energy dispersion X ray analysis (EDAX), and electron spectroscopy for chemical analysis (ESCA). No other sulfur containing species besides CaSO 4 was found. Small amount of CaFe 3(SiO 4) 2OH, some complexes of CaO SiO 2 Fe 2O 3 and vitreous iron oxides were identified on the surface of CaSO 4 grains. This might explain the mechanism of sulfur fixation during coal briquettes combustion.
文摘SHANXI Province, China’s key energy and heavy chemical industry base, boasts rich coal resources. Apart from fulfilling domestic supply requirements, and exporting to European and Asian countries, under the guidance of the provincial Party Committee and provincial government, Shanxi also attaches importance to highly processed coal products.Bestowed generously with nature’s bounty, Lucheng City, in southeastern Shanxi, has over
基金This research was supported by the National Natural Science Foundation of China(Grant No.51806242)the Chinese Universities Scientific Fund(No.2019TC010)+3 种基金the Chinese Universities Scientific Fund-Special Project for"Double First-Class"Initiative of College of Engineering,China Agricultural University,"the Characteristics of Thermal and Mass Flow for Clean Space-heating of Rural Households using Biofuels"the Agricultural Product Quality Inspection Bureau,Ministry of Agriculture and Rural Affairs,China,Agricultural Industry Standard Development Project-"Determination method of major atmospheric pollutants from rural household stoves"(No.181721301092371112)the bilateral China-South Africa MoST-NRF joint project“Development of Scientifically Robust and Culturally Appropriate Metrics and Protocols for Evaluating Clean(Combustion)Cooking Stoves”,sponsored by Ministry of Science and Technology,ChinaInvestigation on South-South Cooperation in Climate Change through Clean Stove Alliance,sponsored by Ministry of Ecology and Environment and Administrative Center for China's Agenda 21(No.0201835).
文摘The extensive use of traditional cooking and heating stoves to meet domestic requirements creates a serious problem of indoor and outdoor air pollution.This study reports the impacts of two fuel feeding methods-front-loading and top-loading on the thermal and emissions performance of a modern coal-fired water-heating and cooking stove using a contextual test sequence that replicates typical patterns of domestic use.Known as a low-pressure boiler,when this stove was fueled with raw coal,the findings indicate that front-loading the fuel,which devolatilizes the new fuel gradually,produced consistently higher space heating efficiency and lower emission factors than top-loading the same stove,which devolatilizes new fuel all at once.Comparing the performance at both high and low power gave the similar results:front-loading with raw coal produced consistently better results than top-loading.The average water heating efficiency when front-loading was(58.6±2.3)%and(53.4±1.8)%for top-loading.Over the sixteen-hour test sequence,front-loading produced 22%lower emissions of PM2.5(3.9±0.6)mg/MJNET than top-loading(4.7±0.9)mg/MJNET.The same pattern was observed for carbon monoxide and the CO/CO2 ratio.CO was reduced from(5.0±0.4)g/MJNET to(4.1±0.5)g/MJNET.The combustion efficiency(CO/CO2 ratio)improved from(8.2±0.8)%to(6.6±0.6)%.Briquetted semi-coked coal briquettes are promoted as a raw coal substitute,and the tests were replicated using this fuel.Again,the same pattern of improved performance was observed.Front loading produced 3.5%higher heating efficiency,10%lower CO and a 0.9%lower CO/CO2 ratio.It is concluded that,compared with top loading,the manufacturers recommended front-loading refueling behavior delivered better thermal,emissions and combustion performance under all test conditions with those two fuels.
