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.     

基于全生命周期的褐煤制气与发电温室气体排放对比研究

我国褐煤资源较为丰富,主要分布于内蒙古东部、云南省和黑龙江省。褐煤主要的传统利用方式是直接燃烧发电,但其存在能效低、污染重等问题。除发电外,褐煤新型利用方式逐渐成熟,制取天然气以及提质后发电就是其中的代表。本文基于全生命周期评价法,计算了褐煤制取天然气与褐煤提质后发电在终端利用能效相同的情况下,产生1 GJ有效能量的温室气体排放量,分别为158.173/e kg/GJ、480.68/e kg/GJ(e为能源终端使用能效)。显然,从温室气体排放角度,褐煤制取天然气优于提质褐煤发电技术。     

内蒙古乌兰诺尔井田6号煤层煤质特征研究

乌兰诺尔井田位于内蒙古自治区东北部,含煤地层主要为白垩系下统巴彦花组,6号煤是区内唯一可采煤层,其显微组分镜质组含量为85.2%～91.0%,惰质组含量为2.0%～13.4%,壳质组在2%以下。测试分析表明6号煤属中灰、低—中高硫、高热值褐煤,其挥发分高,化学反应性好,燃烧时速度快,反应充分,是很好的动力燃料,适用于火力发电。     

压汞实验对低阶煤表征的适用性分析及校正方法

压汞实验在中-高阶煤的孔隙测试中得到了广泛的应用。然而对于低阶煤，由于其煤体疏松、易碎，压汞的增压过程会造成孔隙结构破坏，导致实验结果不准。为了准确评估压汞实验对低阶煤孔隙结构的损伤，选取褐煤和长焰煤为研究对象，同时利用压汞与核磁共振测试煤的孔径分布。结果表明，压实与凝胶化程度低的褐煤和长焰煤，压汞测试过程破坏了其大中孔的原生结构，从而导致中孔比例升高；同时受基质压缩效应影响导致微孔体积偏高。随着煤化作用增强，长焰煤较褐煤所受的影响逐渐减小。进一步通过氮气吸附实验对压汞高压段的测试结果进行校正，以消除基质压缩效应引起的煤体弹性变形所带来的误差，其中，褐煤压汞校正前测试误差为87%，而校正后仅为18%。实验研究表明，联合利用核磁共振测试、氮气吸附实验可显著提高压汞法用于低阶煤孔隙测试结果的准确性。      

Health impacts of coal and coal use: possible solutions

Coal will be a dominant energy source in both developed and developing countries for at least the first half of the 21st century. Environmental problems associated with coal, before mining, during mining, in storage, during combustion, and postcombustion waste products are well known and are being addressed by ongoing research. The connection between potential environmental problems with human health is a fairly new field and requires the cooperation of both the geoscience and medical disciplines. Three research programs that illustrate this collaboration are described and used to present a range of human health problems that are potentially caused by coal. Domestic combustion of coal in China has, in some cases, severely affected human health. Both on a local and regional scale, human health has been adversely affected by coals containing arsenic, fluorine, selenium, and possibly, mercury. Balkan endemic nephropathy (BEN), an irreversible kidney disease of unknown origin, has been related to the proximity of Pliocene lignite deposits. The working hypothesis is that groundwater is leaching toxic organic compounds as it passes through the lignites and that these organics are then ingested by the local population contributing to this health problem. Human disease associated with coal mining mainly results from inhalation of particulate matter during the mining process. The disease is Coal Worker's Pneumoconiosis characterized by coal dust-induced lesions in the gas exchange regions of the lung; the coal worker's “black lung disease”.     

国内外煤炭能源“绿色化”综述

大力开发应用煤炭能源“绿色化”技术,尽可能地减少环境的污染,已成为人们加速开发能源利用新技术的共识。当前国内外开展煤炭能源“绿色化”的技术主要有洁净煤技术、整体燃汽联合循环发电,磁流体发电循环系统,燃料电池、以煤代油等技术。通过“绿色化”技术的开发利用,不但治理了环境,还从煤中提取了城市煤气、甲醇、二甲醚、重油、轻油、酚、硫……等产品,既充分开发利用资源,又可缓解能源的不足,增加了巨大的经济效益和社会可持续发展的效益。     

Analysis of 100% renewable energy for Iran in 2030: integrating solar PV,wind energy and storage

The devastating effects of fossil fuels on the environment, limited natural sources and increasing demand for energy across the world make renewable energy sources more important than in the past. The 2015 United Nations Climate Change Conference resulted in a global agreement on net zero CO₂ emissions shortly after the middle of the twenty-first century, which will lead to a collapse of fossil fuel demand. The focus of the study is to define a cost optimal 100% renewable energy system in Iran by 2030 using an hourly resolution model. The optimal sets of renewable energy technologies, least-cost energy supply, mix of capacities and operation modes were calculated and the role of storage technologies was examined. Two scenarios have been evaluated in this study: a country-wide scenario and an integrated scenario. In the country-wide scenario, renewable energy generation and energy storage technologies cover the country’s power sector electricity demand. In the integrated scenario, the renewable energy generated was able to fulfil both the electricity demand of the power sector and the substantial electricity demand for water desalination and synthesis of industrial gas. By adding sector integration, the total levelized cost of electricity decreased from 45.3 to 40.3 €/MWh. The levelized cost of electricity of 40.3 €/MWh in the integrated scenario is quite cost-effective and beneficial in comparison with other low-carbon but high-cost alternatives such as carbon capture and storage and nuclear energy. A 100% renewable energy system for Iran is found to be a real policy option.     

Coals of Canada: Distribution and compositional characteristics

Canada's coal resources occur in 16 sedimentary basins or groups of basins and range in age from Devonian to Tertiary. The Western Canada Sedimentary Basin (WCSB), which contains the vast majority (about 90%) of the nation's coal resources of immediate interest, underlies a large area in the provinces of British Columbia, Alberta, Saskatchewan and Manitoba, extending northward to about the 62nd Parallel in Yukon and Northwest Territories. Coal deposits in the WCSB range in age from Early Carboniferous (Mississippian) to Paleocene. Rank ranges from lignite to semianthracite. About 36% of the total estimated 71,000 megatonnes of resources of immediate interest in the WCSB is bituminous coal, including a high proportion in the medium to low volatile range. Their low sulphur contents and acceptable ash levels make these medium and low volatile bituminous coals attractive 3s coking feedstocks and large quantities are mined for that purpose. The lower rank western Canadian coals are used mainly for electricity generation.Significant resources of bituminous coal occur in the coalfields of Atlantic Canada where they have been mined since 1720. Most of these coals are classed as high volatile A bituminous and most are used for power generation. Large resources of coal (lignite to anthracite) also occur in more remote regions of Canada, such as the Bowser Basin in northwestern British Columbia, and Sverdrup Basin/ Franklinian Geosyncline in the Arctic Islands. Information on distribution and compositional attributes of these frontier region coals is commonly scarce.     

Value of Information Introduced by a Resource Model Updating Framework

A primary concern of the mining industry is to meet production targets, which are required and defined by customers. Deviations from these targets, in terms of quality and quantity, highly affect the economical aspect. Recently, an efficient resource model updating framework concept has been proposed aiming for the improvement of raw material quality control and process efficiency in any type of mining operation. The concept integrates online sensor measurements, obtained during production, into the resource model. In this way, due to the spatial variability, quality attributes of the blocks that will be produced in the next days or weeks are being updated based on real-time measurements. The concept has been applied in a lignite field with the aim of identifying local impurities in a lignite seam and to improve the prediction of coal quality attributes in neighbouring blocks. This paper investigates the added value of using the resource model updating framework by using the value of information analysis. The expected benefit of additional information (integration of the online sensor measurements into the resource model) is compared to a case where there is no additional information integrated into the process. These benefits are evaluated based on the economic impact determined by applying the resource model updating framework in mine planning.

     

Whey as a substrate for generation of bioelectricity in microbial fuel cell using E.coli

While oil prices raise and the supply remains unsteady, it may be beneficial to use the high content of energy available in food processing wastes, such as cheese whey waste, by converting it to bioenergy. As well, there have been many new waste biotreatment technologies developed recently, which may well be used directly to food processing wastes. Microbial fuel cell represents a new technology for simultaneous use of waste materials and bioelectricity generation. In this study, bioelectricity generation with whey degradation was investigated in a two-chamber microbial fuel cell with mediators. E.coli was able to use the carbohydrate found in whey to generate bioelectricity. The open-circuit voltage in absence of mediator was 751.5mV at room temperature. The voltage was stable for more than 24 h. Riboflavin and humic acid were used as conceivable mediators. The results showed that humic acid was a few times more effective than Riboflavin. Additionally, four chemicals employed as catholyte. Based on polarization curve, FeCl₃ (III) was the best. Maximum power generation and current were 324.8 μW and 1194.6μA, respectively.     

Reduction of environmental pollution through optimization of energy use in cement industries

Industrial development has lead to higher energy consumption, emission of greenhouse gases, as well as air pollutants. Cement factories play an important role in over all greenhouse emissions. This study aims to investigate the role of Iranian cement industries and their contribution of greenhouse gases contribution. The measured emission factors for oil and fuel gas shows that carbon dioxide contribution from fuel oil based cement industries is almost 2.7 times higher than gas based cement factories. The strength, weakness, opportunity and threat technique analysis showed that the best strategy to combat greenhouse gases from Iranian cement factory is to implement energy efficiency measures. Further, strategic position and action evaluation matrix analysis indicates that Iranian cement industries fall within invasive category. Therefore, exploitation of opportunities must carefully be used. One of these opportunities is the utilization of financial assistance provided by clean development mechanism. The results show that replacement of ball mills with vertical roller mill can reduce the electricity consumption from 44.6 to 28 kWh/ton. As a result of such substitution about 720 million kWh/y of electricity would be saved (almost a power plant of 125 MW capacities). Though implementation of new mills may not be economic for the cement industries’ owner, but the overall gain for the government of Iran will be about US$ 304 million. If the duration of such efficiency measure is considered as about 12 y, then the overall CO₂ reduction/phase-out would be around 4.3 million tons.     

长壁孤岛工作面冲击失稳能量场演化规律

煤矿冲击地压一直是困扰中国煤矿安全的主要问题,而煤矿开采过程中跳采形成的孤岛工作面由于容易产生应力集中,来压强度提高,极容易发生冲击地压。基于唐山矿T2193下孤岛工作面的地质条件,从数值分析的角度研究了煤岩体材料的非均匀性,揭示了孤岛工作面顶板周期来压时煤岩体能量释放的动态特征,分析了工作面前方能量释放激增机制。数值模拟结果显示,长壁工作面回采过程中直接顶的不断垮落造成了老顶悬空距离的不断增大,工作面周期来压时,积聚于老顶岩层内的弹性应变能将瞬间释放,容易引发工作面及巷道的冲击失稳。孤岛工作面由于其特有的矿压显现特征,老顶周期破断时所释放的弹性应变能将更加剧烈,冲击地压势必愈加强烈。孤岛工作面顶底板和煤层的能量释放激增可以作为判断煤岩体冲击失稳的前兆信息。孤岛工作面前方发生冲击破坏的主要原因是由于工作面回采过程中围岩所积聚的大量弹性能在顶板断裂时所伴随的巨大能量释放而造成的。     

In-use energy and CO<Subscript>2</Subscript> emissions impact of a plug-in hybrid and battery electric vehicle based on real-world driving

Facilitated by fuel economy, climate legislation and government policy, sales of light-duty plug-in hybrid and battery electric vehicles are rapidly increasing during the last decade. But their energy and emissions impact have not been fully investigated, particularly accounting for energy and emissions during electricity generation. In this study, we conducted in-use energy consumption and emissions measurements of a plug-in and a battery electric vehicle under real-world city and highway driving conditions. We further compare them with energy consumption and emissions from counterpart conventional vehicles under the same driving conditions, to exclude benefits due to different vehicle specifications. Our results show that both the plug-in hybrid and battery electric vehicles can achieve about 50% energy benefits compared with their counterpart conventional vehicles, mainly through capturing regenerative energy. But when vehicles are tested in high-speed or high-acceleration driving conditions, the distance-normalized life-cycle CO₂ emissions of plug-in hybrid and battery electric vehicles are higher to their counterpart gasoline powered vehicles. The CO₂ emissions comparison results can vary based on the location and time of electricity generation. Therefore, our results confirm that benefits of promoting electric vehicles should consider temporal and spatial aspects of electricity generation.     

河北省褐煤资源赋存分布特征与勘查开发利用前景分析

河北省辖区内赋存、分布的褐煤资源形成于早白垩世和第三纪，但由于煤层顶底板岩石固结程度差，建井开采时井巷变形严重，维护困难，致使大量褐煤资源未得以开发利用。根据已有资料分析，褐煤含煤区地质构造条件简单、水文地质条件简单、主要呵采煤层顶板以泥岩或炭质泥岩为主，岩石致密，透气性差。褐煤本身透气性好，燃点低，没有粘结性，挥发分高．受热容易膨胀破裂，诸多因素都表明适合采用煤炭地下气化的开采方式进行开发利用，因此有必要加强我省褐煤资源的地质勘查工作和煤炭地下气化工艺的研究，为今后褐煤开发利用奠定基础。     

The US Geological Survey's national coal resource assessment: the results

The US Geological Survey and the State geological surveys of many coal-bearing States recently completed a new assessment of the top producing coal beds and coal zones in five major producing coal regions—the Appalachian Basin, Gulf Coast, Illinois Basin, Colorado Plateau, and Northern Rocky Mountains and Great Plains. The assessments, which focused on both coal quality and quantity, utilized geographic information system technology and large databases. Over 1,600,000 million short tons of coal remain in over 60 coal beds and coal zones that were assessed. Given current economic, environmental, and technological restrictions, the majority of US coal production will occur in that portion of the assessed coal resource that is lowest in sulfur content. These resources are concentrated in parts of the central Appalachian Basin, Colorado Plateau, and the Northern Rocky Mountains.     

Coal deposits of the United States

The coal fields of the Unites States can be divided into six major provinces. The Appalachian and Interior Provinces contain dominantly bituminous coal in strata of Pennsylvanian age. The coal seams are relatively thin and are mined both by surface and underground methods. Sulfyur content is low to moderate in the Appalachian Province, generally high in the Interior province. The Gulf Coastal Plain Province, in Texas and neighboring states, contains lignite of Eocene age. The seams are 3–25 ft (0.9–7.5 m) thick and are minded in large open pits. The Northern Great Plains Province has lignite and subbituminous coal of Cretaceous, Paleocene and Eocene age. The coal, largely very low in sulfur, occurs in beds up to 100 ft (30 m) thick and is strip-mined. The Rocky Mountain Province contains a great variety of coal deposits in numerous separate intermontane basins. Most of it is low-sulfur subbituminous to bituminous coal iof Creatceous and early Tertiary age. The seams range from a few feet to over 100 ft (30 m) thick. Strip-mining dominates but underground mines are important in Utah and Colorado. The Pacific Coast Province, which includes Alaska, contains enormous cola resources but has seen little mining. The coal is highly diverse in physical character and geologic setting.     

用水合理性评价指标探讨

用水合理性不能简单根据灌溉定额、万元工业产值用水量的高低来判断.在比较各地灌溉定额、工业用水定额的高低时,应考虑各地种植制度、产业结构的特殊性.用水合理性评价应该考虑用水的可持续性、社会公平和经济效率三个方面,并建立和采用较全面的评价指标体系.尤其值得注意的是:因为其它资源及其开发的空间分布的限制,水资源利用效率的空间分布偏离了越是资源紧缺的地区资源利用效率越高的一般规律,耗水大的行业如煤炭采选业、火电工业也可能布局在水资源较缺乏的地区.     

沁水盆地南部柿庄南区块煤层气地质特征

以国家科技重大专项《山西沁水盆地南部煤层气直井开发示范工程》成果为依据,以以往的地质勘查及研究成果为参考,对沁水盆地南部柿庄南区块煤层气地质特征进行分析。分析认为南部柿庄南区块构造简单,煤变质程度高、煤层厚度大、埋深适中而且分布稳定,有利于煤层气生成,煤层吸附能力较强,储层渗透率较好,煤层气保存条件好,是沁南煤层气勘探开发最有利区块之一。开发利用该区块煤层气资源,可有效改善地区能源结构、加快区域经济发展,降低后期煤炭开发风险,具有非常可观的社会及经济效益。     

光伏屋顶项目发电系统设计与分析

基于建筑屋顶面积大、无遮阳等具有可利用光伏屋顶发电的有利条件,本文以山西某市职中校区内的建筑物为例,从气象条件、系统运行方式、光伏电池方阵设计及并网电气设计等方面提出了综合优化设计方案。     

Economics of the coal industry east of the Mississippi, 1973–1982

Government regulations on health, safety and environment have been poppular blamed for the declining productivity in U.S. coal mines since 1970. The stagnation in the coal industry east of the Mississippi is alleged to have been caused by this declining productivity and by the growth of cheaper and cleaner coal production west of the Mississippi. Economic evidence suggests, however, that productivity declines were more due to a relative lowering of labor costs in comparison with coal prices and due to work stoppages. The development of western coals fields was spurred by growth in local demand and had only a relatively small impact on coal production east of the Mississippi. Problems of the eastern coal industry are rooted mainly in slow economic growth in eastern U.S. which must be addressed in the long-term interests of the eastern coal industry.