Hydrogen from coal: Production and utilisation technologies

Although coal may be viewed as a dirty fuel due to its high greenhouse emissions when combusted, a strong case can be made for coal to be a major world source of clean H₂ energy. Apart from the fact that resources of coal will outlast oil and natural gas by centuries, there is a shift towards developing environmentally benign coal technologies, which can lead to high energy conversion efficiencies and low air pollution emissions as compared to conventional coal fired power generation plant. There are currently several world research and industrial development projects in the areas of Integrated Gasification Combined Cycles (IGCC) and Integrated Gasification Fuel Cell (IGFC) systems. In such systems, there is a need to integrate complex unit operations including gasifiers, gas separation and cleaning units, water gas shift reactors, turbines, heat exchangers, steam generators and fuel cells. IGFC systems tested in the USA, Europe and Japan employing gasifiers (Texaco, Lurgi and Eagle) and fuel cells have resulted in energy conversions at efficiency of 47.5% (HHV) which is much higher than the 30–35% efficiency of conventional coal fired power generation. Solid oxide fuel cells (SOFC) and molten carbonate fuel cells (MCFC) are the front runners in energy production from coal gases. These fuel cells can operate at high temperatures and are robust to gas poisoning impurities. IGCC and IGFC technologies are expensive and currently economically uncompetitive as compared to established and mature power generation technology. However, further efficiency and technology improvements coupled with world pressures on limitation of greenhouse gases and other gaseous pollutants could make IGCC/IGFC technically and economically viable for hydrogen production and utilisation in clean and environmentally benign energy systems.     

Establishment of new structural indices for the coals with various susceptibilities to self-ignition

One of the main aims of the coal industry is to improve conditions and increase the safety of the work. The questions of environment also need to be considered. In the complex of science-technological problems the focus is placed on how to reveal spontaneous combustion of coals and siltages. The results of spontaneous combustion of coals and siltages are bereavement of the minerals, promise for failures and accidents, and pollution of the environment. The decision of problem of the prevention is very hard, because the spontaneous combustion of coals is an unforeseeable and poorly studied process. The methods of preventing spontaneous combustion of coals must be established. In the first place, these investigations must start with the study of the structure of these coals. The aim of the present work is to determine the differences in the structure of coals with various susceptibilities to spontaneous combustion .Main methods of studying coals include ultimate and proximate analyses, petrographic analysis, analysis of ashes, X-ray （apparatus ＂Kristalloflex Siemens＂ using filtered cuprum radiation）, extraction （Dionex ASE 200）, gas chromatography-mass spectroscopy （GC-MS） Finnigan MAT GCQ. Proximate, ultimate and petrographic analyses revealed the distinction in the structure of coals with various susceptibilities to self-ignition.     

Heavy metal and arsenic distributions in soils surrounding Palapye, Botswana： An evaluation of environmental impact of coal mining and combustion in a sub-arid region

Coal is an important natural resource in Botswana. The best coals so far found occur in the Morupule coalfield, west of Palapye, where nearly 8000 million tons have been identified （Carney et al., 1994）. In this study we investigate the environmental impact of the mining and consumption of the high-ash, medium-calorific value bituminous coal in the eastern part of Botswana, which may serve as a reference for other coal mines and coal-based power stations around the globe. More than two hundred surface soil samples and three profile soil samples were collected around Morupule Colliery, Morupule Power Station and Palapye.     

Study on the distribution of PAHs in fly ash from coal and residual char combustion in a pressurized fluidized bed

Direct coal combustion not only has a low utilizing efficiency, but also produces a large amount of pollutants such as particulate, CO2, SO2, NOx, polycyclic aromatic hydrocarbons （PAHs）, PCDD/PCDFs, and so on. Coal gasification is a clean coal technology that presents good prospects for coal use, mainly for producing electricity with a high coal conversion efficiency and low environmental impact. However, there is a problem about the minimization of PAHs in coal gasification or direct coal combustion. PAHs are harmful to the environment and human health due to their high degree of mutagenicity and carcinogenicity when they enter human bodies through breathing, eating, and drinking. It is said that about 75%-90% cancers of human beings are mainly caused by PAHs. So the US EPA has prioritized 16 PAH compounds as hazardous air pollutants; these compounds are naphthalene （NAP）, acenaphthylene （AcPy）, acenaphthene （AcP）, fluorene （Flu）, phenanthrene （PhA）, anthracene （ANT）, fluoranthene （FluA）, pyrene （Pyr）, benzo （a） anthracene （BaA）, chrysene （Chr）, benzo （b） fluoranthene （BbF）, benzo （k） fluoranthene （BkF）, benzo （a） pyrene （BaP）, indeno（1,2,3,-cd） pyrene [In（1,2,3-cd） P], dibenzo （a,h） anthracene （DbA）, and benzo （ghi） perylene （BghiP）. The residual char is one of the main products during coal gasification, and then it is brought into the combustion chamber to combust. To investigate the distribution of PAHs in fly ash, the combustion of coal and residual char was tested in a pressurized spouted fluidized bed. After Soxhlet extraction and K-D concentration, the contents of 16 PAHs recommended by US EPA in coal, residual char, and fly ash, were analyzed by a HPLC coupled with fluorescence and diode-array detection.     

地震学在减轻矿山地质灾害中的应用进展

综述了煤矿安全对于地球物理应用的需求,以及近年来地震学在煤矿减轻地质灾害的应用进展,特别是微震监测分析在若干典型煤矿应用得到的初步成果。这些成果不但对于煤矿安全具有重要意义,而且对于认识构造地震成因和验证预测方法,也具有中尺度试验意义。     

Coexistence and inherence of diverse energy resources in the Ordos Basin, China

1 Introduction In recent years rapid economic developmentbadly needs energy resources. Exploration andexploitation of more kinds of energy resources shouldbe intensified to meet this need. According to presentliterature, oil/gas fields, coal fields as we…     

蔚县矿区奥陶系下统灰岩岩溶发育规律及煤层开采对策研究

在充分收集蔚县矿区勘探资料、生产矿井资料的基础上,进行了归纳整理与分析研究,总结出矿区奥陶系下统灰岩岩溶发育规律(岩溶发育程度在平面上划分为三个区,垂向上大致可分为三个带)及岩溶水的赋存条件,并提出了受奥陶系下统岩溶水威胁的1、5号煤层的以防为主,带压开采、不直接疏排岩溶水的技术和方法和开采对策。     

煤田地质勘查组织需“确认的过程”辩识

对目前在煤田地勘单位贯彻ISO 9001:2000标准7.5.2条款中对需确认的过程的不同观点进行了分析,从“过程确认”的概念入手,并结合煤田地质勘查组织生产和服务提供过程及其特点,提出了煤田地质勘查单位需确认的过程的识别和控制方法。     

介绍一种简易快捷的煤层瓦斯含量的计算方法

大量煤层瓦斯解吸资料表明，解吸瓦斯量（Q）与煤样气体解吸时间的开方（θ），呈Q=ab/θ（b＜0）曲线的相关关系一依据这种关系，由现场瓦斯煤样的解吸资料，建立起θ与Q的回归方程，再按《煤层气测定方法（解吸）MT／T77—1994》中的有关规定计算出损失瓦斯及在化验室测试的常温下煤层瓦斯的自然组分、可燃物质量等数据，进而便可求得煤层瓦斯含量值。该方法在江西省丰城矿区石上井田勘探工作中取得了较好的效果。     

贵州西部氟中毒地区氟来源地质背景研究

贵州省西部广泛分布上二叠统煤系地层,燃煤型氟中毒严重影响当地居民的身体健康。引起氟中毒的氟是多来源的,影响氟中毒的因素是多方面的。高氟含量的岩石粘土岩、煤、页岩等是氟的初始来源体;高氟含量土壤是氟第二个层次的来源;高氟含量土壤中种植的农作物是第三个层次的来源;燃煤烟尘直接排放室内空气中和用燃煤烘烤食物等,使空气、食物和水中氟含量增高,是一重要的人为氟来源。人通过呼吸高氟含量的空气和食(饮)用高氟含量的食物(水)将氟沉淀在体内,造成氟中毒。