Assessing determinants of industrial waste reuse: The case of coal ash in the United States

Devising effective strategies to facilitate waste reuse depends on the solid understanding of reuse behaviors. However, previous studies of reuse behavior have been limited in scope, focusing mostly on household recycling behaviors or very limited types of industrial wastes. To gain a better understanding of the business reuse behaviors, this study examined the impact of various factors in technical, economic, regulatory, and behavioral categories in the case of coal ash generated in the United States. The results of fixed effect models for fly ash and bottom ash particularly showed the significance role of the behavioral factor. In both models, a proxy variable, which represents knowledge sharing among the power plants or the utility's decision-making, turned out to be statistically significant and had the largest coefficient estimates among a group of variables. This finding may imply that the characteristics of waste reuse behavior are determined more by business decision-making behaviors than by market or institutional factors. However, the role of the behavioral variable was stronger in the bottom ash models than in the fly ash models. While the reuse of bottom ash was determined primarily by the behavioral variable, fly ash reuse was determined by more diverse factors including economic and regulatory variables. This could be explained by material characteristics in relation to competing resources and the nature of reuse applications.     

Detailed in-furnace measurements with reburning of superfine pulverized coal in high CO2 concentration

This paper presents detailed measurements of gaseous species during the reburning process with high CO₂ concentration in a bench-scale furnace. Superfine pulverized coal, with the average particle size below or around 20 μm, is used as the reburning fuel. The data of flue gas concentration (NO_x, HCN, NH₃, CH₄, O₂, CO, CO₂ etc.) is obtained in order to reveal the intrinsic connection between NO_x emissions and other influential gaseous species at different positions of the furnace. The finding concludes that the advantage of superfine pulverized coal with regard to NO reduction is more efficient in homogeneous stage rather than heterogeneous stage. Meanwhile, the evolution of HCN and CH₄ agrees well with each stage of NO reduction, which indicates that these gaseous species are favorable for NO abatement. Eventually, oxygen consumption rate for superfine pulverized coal is relatively faster, conducive to strengthen both homogeneous and heterogeneous NO reduction under CO₂ reburning condition.     

Concentrations and modes of occurrence of trace elements in the Late Permian coals from the Puan Coalfield, southwestern Guizhou, China

The concentration, mode of occurrence, and origin of trace elements in the Late Permian coals from the Puan Coalfield, southwestern Guizhou, China, were examined using inductively coupled plasma-mass spectrometry (ICP-MS), X-ray fluorescence (XRF), cold-vapor atomic absorption spectrometry (CV-AAS), ion-selective electrode method (ISE), sequential chemical extraction procedure (SCEP), scanning electron microscopy equipped with energy-dispersive X-ray (SEM-EDX), and optical microscope. Results show that minerals in the No. 2 Coal from the Puan Coalfield were mainly made up of epigenetic pyrite of low-temperature hydrothermal fluid origin and kaolinite of detrital terrigenous origin. Elements including As (36.9 μg/g), Cd (10.2 μg/g), Cr (167.3 μg/g), Cu (365.4 μg/g), Hg (2.82 μg/g), Mo (92.6 μg/g), Ni (82.6 μg/g), Pb (184.6 μg/g), Se (6.23 μg/g), Zn (242.3 μg/g), and U (132.7 μg/g) are significantly enriched in the No. 2 Coal from the Puan Coalfield. However, concentrations of trace elements in the other four coals, the No. 1, No. 8, No. 11, and No. 18 Coals, were close to the usual ranges found for Guizhou of China, China, and USA. Results of SEM-EDX and SCEP showed that As, Cd, Hg, Mo, Ni, Pb, and Zn occur mainly in veined pyrite, while Cr, Cu, and U distribute mainly in kaolinite, indicating that the low-temperature hydrothermal fluid and detrital materials of terrigenous origin are the main contributors to the enrichment of these trace elements in the No. 2 Coal.     

“十五”期间沈阳市煤炭消费与大气污染相关性分析

通过对沈阳市“十五”期间经济发展所引起的煤炭消费量与大气污染之间的关系进行分析后可知,“十五”期间沈阳市煤炭消耗量与大气污染物排放量、大气环境质量均呈现为“负相关性”,经解析,“十五”期间由于沈阳市采取了煤炭管制、推行集中供热提高煤炭使用效率等手段,使得煤炭消费在增长的情况下大气污染物排放量降低、环境空气质量逐步改善,呈现为“负相关性”。     

基于傅里叶红外光谱法测定燃煤电厂烟气中SO3与H2SO4

基于傅里叶红外光谱法(FTIR)监测燃煤电厂烟气处理流程中的SO3与H2 SO4.结果表明,布袋除尘进口、出口和烟囱出口的SO3与H2SO4之和(SO3+H2SO4)分别为(29.33±2.30)mg/m3、(25.15±1.63)mg/m3和(12.13±1.26)mg/m3;布袋除尘与湿法脱硫对SO3+H2 SO4...     

Reduction and utilization of coal mine waste rock in China: A case study in Tiefa coalfield

In China, coal mine waste rock (CMWR) produced during coal mining and processing is still increasing significantly as a result of coal production which has huge environmental impact. CMWR reduction and utilization is a major issue for coal enterprises and government to reduce the surface footprint and the public environmental impact. Tiefa coalfield, an old coalfield with 60 years of coal exploitation, was selected as a case to study the methods to minimize the environmental impacts of CMWR piles in a short period. We argue that a systematic design on CMWR utilization is needed on the basis of a usage evaluation which takes consideration of CMWR source, compositions, and proximate analysis. Mine design is crucial and the base for reducing the CMWR generation at the headstream. Placing roadway into coal seam rather than rock, panel optimization, and parametric analysis for mining technique were conducted in Tiefa coalfield. A promising technology of CMWR backfill under the ground was employed with a resultant increase of coal recovery rate. The surface CMWR recycling depends on brick making, electricity generating, and rehabilitation of subsided land. The practice of the presented methods indicates that the CMWR piles on Tiefa coalfield may disappear in 3 years, which could significantly reduce the environmental impacts of CMWR dumps. The technologies conducted in Tiefa coalfield developed a model of CMWR reduction and utilization for Chinese coal mines.