Coal-to-Liquids: Potential Impact on U.S. Coal Reserves

The production of liquid fuels from coal will very likely become an important part of the hydrocarbon energy mix of the future, provided that technical and environmental obstacles are overcome economically. The coal industry should be able to handle a coal-to-liquids (CTL) industry of modest size, using 60–70 million short tons or 54–64 million metric tonnes of coal per annum, without premature depletion of the country’s coal reserves. However, attempts to use CTL technology to replace all petroleum imports would deplete the nation’s coal reserves by the end of the century.     

Examining the influence of settlement morphology and separation zones policies on the availability of shallow coal resources in the United Kingdom

In 2013, demand for coal in the UK was 60 million tonnes. Of this, 12.7 million tonnes (21%) came from indigenous sources; the majority of which was from surface mining (8.6 million tonnes). Many planning applications for surface mining of coal and the coal extraction that follows, are often a source of conflict with the communities who live within shallow coalfield areas. Policies which enforce a gap, or ‘separation zone’, between communities and surface coal mining operations exist in Wales and Scotland, but do not exist in England. This paper examines the effect of applying separation zones on the availability of shallow coal resources within two study areas; one within the South Wales Coalfield, the other within the Midlands Coalfield (comprising the Yorkshire, Nottinghamshire and North Derbyshire Coalfield areas). Density profiles and a shape-index algorithm are used to compare and contrast settlement morphology (i.e. shape or footprint) and distribution to determine whether they have a bearing on the areal extent of any potential separation zone applied. The implications on the availability of shallow coal resources of applying different separation zone distances around settlements within these two areas are explored. Results reveal that although the settlement morphology is important in determining the area of the separation zone, and has greatest influence in the South Wales Coalfield, the area of coal resource sterilised by the application of separation zones is greatest in the Midlands Coalfield due to it having a higher proportion of urban development situated on the surface extent of the shallow coal resource.     

Estimation of Coal Reserves for UCG in the Upper Silesian Coal Basin,Poland

One of the prospective methods of coal utilization, especially in case of coal resources which are not mineable by means of conventional methods, is underground coal gasification (UCG). This technology allows recovery of coal energy “in situ” and thus avoid the health and safety risks related to people which are inseparable from traditional coal extraction techniques. In Poland most mining areas are characterized by numerous coal beds where extraction was ceased on account of technical and economic reasons or safety issues. This article presents estimates of Polish hard coal resources, broken down into individual mines, that can constitute the basis of raw materials for the gasification process. Five mines, representing more than 4 thousand tons, appear to be UCG candidates.     

Quantitative assessment of future development of cooper/silver resources in the Kootenai National Forest,Idaho/Montana: Part I—Estimation of the copper and silver endowments

Faced with an ever-increasing diversity of demand for the use of public lands, managers and planners are turning more often to a multiple-use approach to meet those demands. This approach requires the uses to be mutually compatible and to utilize the more valuable attributes or resource values of the land. Therefore, it is imperative that planners be provided with all available information on attribute and resource values in a timely fashion and in a format that facilitates a comparative evaluation.The Kootenai National Forest administration enlisted the U.S. Geological Survey and U.S. Bureau of Mines to perform a quantitative assessment of future copper/silver production potential within the forest from sediment-hosted copper deposits in the Revett Formation that are similar to those being mined at the Troy Mine near Spar Lake. The U.S. Geological Survey employed a quantitative assessment technique that compared the favorable host terrane in the Kootenai area with worldwide examples of known sediment-hosted copper deposits. The assessment produced probabilistic estimates of the number of undiscovered deposits that may be present in the area and of the copper and silver endowment that might be contained in them.Results of the assessment suggest that the copper/silver deposit potential is highest in the southwestern one-third of the forest. In this area there is an estimated 50 percent probability of at least 50 additional deposits occurring mostly within approximately 260,000 acres where the Revett Formation is thought to be present in the subsurface at depths of less than 1,500 meters. A Monte Carlo type simulation using data on the grade and tonnage characteristics of other known silver-rich, sediment-hosted copper deposits predicts a 50 percent probability that these undiscovered deposits will contain at least 19 million tonnes of copper and 100,000 tonnes of silver. Combined with endowments estimated for identified, but not thoroughly explored deposits, and deposits that might also occur in the remaining area of the forest, the endowment potential increases to 23 million tonnes of copper and 190,000 tonnes of silver.     

黄河近年径流泥沙剧减的多因素贡献率分析（英文）

The Yellow River basin is well known for its high sediment yield. However, this sediment yield has clearly decreased since the 1980 s, especially after the year 2000. The annual average sediment yield was 1.2 billion tons before 2000, but has significantly decreased to 0.3 billion tons over the last 10 years. Changes in discharge and sediment yield for the Yellow River have attracted the attention of both the Central Government and local communities. This study aimed to identify the individual contributions of changes in precipitation and human activities(e.g. water conservancy projects, terracing, silt dams, socio-economic and needs, and soil and water conservation measures) to the decrease in discharge and sediment yield of the Yellow River. The study used both improved the hydrological method and the soil and water conservation method. The study focused on discharge analysis for the upper reaches and the investigation of sediments for the middle reaches of the river. The results showed that discharge and sediment yield have both presented significant decreasing trends over the past 50 years. Precipitation showed an insignificant decreasing trend over the same period. The annual average discharge decreased by 5.68 billion m3 above Lanzhou reach of the Yellow River from 2000 to 2012; human activities(e.g. socio-economic water use) contributed 43.4% of the total reduction, whereas natural factors(e.g. evaporation from lakes, wetlands and reservoirs) accounted for 56.6%. The decrease in annual discharge and sediment yield of the section between Hekouzhen station and Tongguan station were 12.4 billion m3 and 1.24 billion tons, respectively. Human activities contributed 76.5% and 72.2% of the total reduction in discharge and sediment yield, respectively, and were therefore the dominant factors in the changes in discharge and sediment yield of the Yellow River.     

新建煤矿区循环经济发展探讨——以河南省新郑煤矿为例

新建煤矿发展循环经济是避免"三农四矿"问题的有效途径.在研究煤炭产业循环经济发展模式的基础上,以正在建设中的新郑煤矿区为例,运用SWOT方法分析了其社会经济基础,提出了目标、指标体系、总体框架和发展模式,并从区域可持续发展的角度提出了新建煤矿区在初期可按"煤-电-建"的模式发展,中后期可按"煤化工"的模式发展,并在企业、园区和社会3个层面建立循环型工业体系、循环型农业体系、资源节约型社会体系和绿色社区体系四大循环体系,为其他新建煤矿区的发展提供借鉴和示范作用.     

1990-2010年中国耕地变化对粮食生产潜力的影响

1990年以来,在国家生态环境保护工程实施、经济快速增长等因素的影响下,中国耕地数量与空间格局发生了巨大变化,对粮食生产潜力造成了巨大影响。本文采用GAEZ模型,结合中国气象、地形、土壤等因素,定量分析了中国耕地粮食生产潜力空间特征以及1990-2010年中国耕地变化对粮食生产潜力的影响。主要结论如下：① 2010年全国耕地粮食生产潜力总量为10.55亿t,全国耕地平均粮食生产潜力为7614 kg/hm²。中国耕地粮食生产潜力存在显著的空间差异,总体表现为东部高而西北部较低的趋势,并且高值区主要分布在长江中下游地区和华南区。② 1990-2010年的20年间,中国耕地粮食生产潜力变化表现出明显的时空差异,总体呈现南减北增、总量减少的基本特征。新增耕地粮食生产潜力的重心逐步由东北向西北转移。耕地粮食生产潜力总量净减少297万t,占2010年全国实际粮食总产量的0.29%。③ 在1990-2000年与2000-2010年两个时期,耕地变化对耕地粮食生产潜力影响差异明显。前10年,耕地粮食生产潜力总量净增加1011万t,主要集中在东北平原区和北方干旱半干旱区;后10年,耕地粮食生产潜力总量净减少1308万t,主要集中在长江中下游地区和黄淮海平原区。从总体看,近20年来耕地粮食生产潜力总量增加主要是由林、草地和未利用土地开垦所导致,而耕地粮食生产潜力总量减少主要是由城市扩展和退耕还林还草所导致。     

Analysis of the contribution of multiple factors to the recent decrease in discharge and sediment yield in the Yellow River Basin,China

The Yellow River basin is well known for its high sediment yield. However, this sediment yield has clearly decreased since the 1980s, especially after the year 2000. The annual average sediment yield was 1.2 billion tons before 2000, but has significantly decreased to 0.3 billion tons over the last 10 years. Changes in discharge and sediment yield for the Yellow River have attracted the attention of both the Central Government and local communities. This study aimed to identify the individual contributions of changes in precipitation and human activities (e.g. water conservancy projects, terracing, silt dams, socio-economic and needs, and soil and water conservation measures) to the decrease in discharge and sediment yield of the Yellow River. The study used both improved the hydrological method and the soil and water conservation method. The study focused on discharge analysis for the upper reaches and the investigation of sediments for the middle reaches of the river. The results showed that discharge and sediment yield have both presented significant decreasing trends over the past 50 years. Precipitation showed an insignificant decreasing trend over the same period. The annual average discharge decreased by 5.68 billion m³ above Lanzhou reach of the Yellow River from 2000 to 2012; human activities (e.g. socio-economic water use) contributed 43.4% of the total reduction, whereas natural factors (e.g. evaporation from lakes, wetlands and reservoirs) accounted for 56.6%. The decrease in annual discharge and sediment yield of the section between Hekouzhen station and Tongguan station were 12.4 billion m³ and 1.24 billion tons, respectively. Human activities contributed 76.5% and 72.2% of the total reduction in discharge and sediment yield, respectively, and were therefore the dominant factors in the changes in discharge and sediment yield of the Yellow River.     

Subsurface Sequestration of CO<Subscript>2</Subscript> in the U.S: Is it Money Best Spent?

The continuously decreasing average coal rank (heating value), inadequate investment, and ever stricter air-emission controls have caused the average efficiency of electricity generation from coal in the U.S. to plummet to a mere 32% by the year 2008. The U.S. gas-fired powerplants are 30% more efficient than the coal-fired ones, with average efficiency of 43% in 2008. Replacing each 1,000 MW _e generated by an average coal-fired powerplant with an average gas-fired powerplant would avoid today 7 million tonnes of CO₂ emissions, 1.2 million tonnes of toxic ash, and significant issues with water contamination. The parallel upgrades to the more efficient supercritical steam turbines would decrease current emissions by up to 50% (from the current average plant efficiency of 32% to over 45%). The CO₂ captured in the new combined-cycle powerplants might be used to enhance oil recovery in local fields, where feasible. The CO₂ enhanced oil recovery (EOR) can never become the main sink for the gigantic CO₂ volume generated each year by electric powerplants. Currently, EOR could absorb only 1% of that volume.     

Assessment of Alaska’s North Slope Oil Field Capacity to Sequester CO2

The capacity of 21 major fields containing more than 95% of the North Slope of Alaska’s oil were investigated for CO₂ storage by injecting CO₂ as an enhanced oil recovery (EOR) agent. These fields meet the criteria for the application of miscible and immiscible CO₂-EOR methods and contain about 40 billion barrels of oil after primary and secondary recovery. Volumetric calculations from this study indicate that these fields have a static storage capacity of 3 billion metric tons of CO₂, assuming 100% oil recovery, re-pressurizing the fields to pre-fracturing pressure and applying a 50% capacity reduction to compensate for heterogeneity and for water invasion from the underlying aquifer. A ranking produced from this study, mainly controlled by field size and fracture gradient, identifies Prudhoe, Kuparuk, and West Sak as possessing the largest storage capacities under a 20% safety factor on pressures applied during storage to avoid over-pressurization, fracturing, and gas leakage. Simulation studies were conducted using CO₂ Prophet to determine the amount of oil technically recoverable and CO₂ gas storage possible during this process. Fields were categorized as miscible, partially miscible, and immiscible based on the miscibility of CO₂ with their oil. Seven sample fields were selected across these categories for simulation studies comparing pure CO₂ and water-alternating-gas injection. Results showed that the top two fields in each category for recovery and CO₂ storage were Alpine and Point McIntyre (miscible), Prudhoe and Kuparuk (partially miscible), and West Sak and Lisburne (immiscible). The study concludes that 5 billion metric tons of CO₂ can be stored while recovering 14.2 billion barrels of the remaining oil.     

中国能源供需EMD分析及动力学预测

根据我国能源总供给和总需求的统计数据,运用EMD方法对我国能源供需情况进行多尺度分析,构建带有周期波动的中国能源供需动力学模型,揭示其动力特征,进行数值模拟并提出虚拟能源理论。研究结果表明:到2020年我国能源生产量为35.6亿t标准煤,能源消费量为42.93亿t标准煤,供需缺口达7.33亿t标准煤,可见我国能源消费速度远远大于能源生产速度。我国未来的能源安全问题十分严峻。     

Potential for Coal-to-Liquids Conversion in the U.S.-Resource Base

By applying the multi-Hubbert curve analysis to coal production in the United States, we demonstrate that anthracite production can be modeled with a single Hubbert curve that extends to the practical end of commercial production of this highest-rank coal. The production of bituminous coal from existing mines is about 80% complete and can be carried out at the current rate for the next 20 years. The production of subbituminous coal from existing mines can be carried out at the current rate for 40–45 years. Significant new investment to extend the existing mines and build new ones would have to commence in 2009 to sustain the current rate of coal production, 1 billion tons per year, in 2029. In view of the existing data, we conclude that there is no spare coal production capacity of the size required for massive coal conversion to liquid transportation fuels. Our analysis is independent of other factors that will prevent large-scale coal liquefaction projects: the inefficiency of the process and either emissions of greenhouse gases or energy cost of sequestration.

Geologic Coal Assessment: The Interface with Economics

Geologic resource assessments describe the location, general characteristics, and estimated volumes of resources, whether in situ or technically recoverable. Such compilations are only an initial step in economic resource evaluation. This paper identifies, by examples from the Illinois and Appalachian basins, the salient features of a geologic assessment that assure its usefulness to downstream economic analysis. Assessments should be in sufficient detail to allocate resources to production units (mines or wells). Coal assessments should include the spatial distribution of coal bed characteristics and the ability to allocate parts of the resource to specific mining technologies. For coal bed gas assessment, the production well recoveries and well deliverability characteristics must be preserved and the risk structure should be specified so dryholes and noncommercial well costs are recovered by commercially successful wells.     

中国碳排放的空间格局及分布动态演进——基于县域碳排放数据的实证研究

基于中国1997—2017年2725个县域单元的碳排放数据,采用标准差椭圆、Theil指数三阶段嵌套分解和Kernel密度估计等方法,全面考察中国碳排放的空间格局及分布动态演进。研究发现：① 中国碳排放由1997年的30.97亿t增长到2012年的93.08亿t,年均增长达到7.86%,而后围绕93亿t上下波动,未出现下降的拐点。② 在空间分布上,中国碳排放呈现东高西低的分布格局,表现出东北-西南方向向心集聚、西北-东南方向空间发散的趋势。③ 在空间差异上,Theil指数三阶段嵌套分解结果表明,中国碳排放的总体差异呈下降趋势,地级行政单元内部差异的贡献率由1997年的43%增加到2017年49%,成为中国碳排放总体区域差异的主要来源。④ 在分布动态演进上,中国县域单元的碳排放存在空间收敛模式,具有显著的空间正相关性,地区间的相互作用影响中国碳排放的未来空间分布。     

渭北矿区土壤侵蚀评估及驱动因素分析

陕西省渭北矿区地处黄土高原,受到自然环境和煤炭开采等人类活动的双重影响,该地区土壤侵蚀更为严重,生态环境更加脆弱。以渭北矿区为研究对象,基于RUSLE模型对渭北矿区土壤侵蚀进行了评估,并综合植被覆盖度、多年平均降水量、坡度、土地利用类型和煤炭年产量等影响因子,应用地理探测器方法对渭北矿区土壤侵蚀进行定量归因。研究结果对矿区水土流失防治具有一定参考价值。结果表明：（1）渭北矿区土壤侵蚀以微度和轻度侵蚀为主,土壤侵蚀严重的区域主要位于研究区西南部、中部和东南部。（2）植被覆盖度和多年平均降水量是造成研究区土壤侵蚀的主导因子,坡度介于20°~25°的地区、植被覆盖度小于0.3的区域和裸地是发生土壤侵蚀的高风险区。（3）渭北矿区各因子协同作用对土壤侵蚀的解释力均大于单因子解释力,因此多个因子共同作用会对土壤侵蚀造成显著影响。     

基于D-InSAR的煤矿区开采沉陷遥感监测技术分析

该文在综合分析国内外开采沉陷监测技术现状、合成孔径雷达干涉测量(InSAR)和差分干涉测量(D-In SAR)技术发展及其在地表沉陷监测中应用成果的基础上,分析了D-InSAR技术在煤矿开采沉陷变形监测中的特点与技术优势。指出:应用D-InSAR进行煤矿区开采沉陷监测的具体目标是矿区地表沉降演变过程分析、采区地表沉陷动态监测与分析和矿区DEM数据更新;亟须研究解决的关键技术问题有:源数据获取与选择、数据处理方法、地面配合措施、精度与可靠性评价、多源信息集成分析等。D-InSAR为煤矿区地表时空演变过程研究和开采沉陷实时动态监测提供了新的技术方法;作为"数字矿山"的重要内容,D-InSAR可以有效地指导矿区生产、整体规划与长远发展,并为矿区可持续发展服务。     

内蒙古呼伦贝尔草原湖泊变化研究

内蒙古呼伦贝尔地区湖泊数量多,面积大,占内蒙古湖泊总面积的58％.近年来该地区湖泊趋于萎缩,但是已有研究主要关注大型湖泊,缺乏对该地区湖泊整体,尤其是小型湖泊(<1 km2)的研究.通过利用Landsat系列(TM、ETM+、OLI)卫星数据,参照该地区湖泊图集、湖泊名录以及Google Earth高清影像,分析了19...     

矿区废弃土地复垦潜力评价方法与应用实例

文章根据实地调查研究,筛选出了影响矿区废弃土地复垦潜力的自然和社会经济条件方面的4类14个亚类因子,并划分为6个等级。运用层次分析法,参考专家评分,来确定矿区废弃土地复垦综合潜力值的大小及每一级别的值域范围。以河南省平顶山市焦店乡为例,阐明了进行矿区废弃地复垦潜力评价的具体过程与方法,可为全国矿区废弃地复垦潜力评价及矿区废弃地有效合理利用提供有益参考。     

我国西南地区的水供应和粮食生产潜力

我国西南地区天然水源非常丰沛,总的可利用量达９４００亿ｍ＾３／ａ,但工程调节能力较低,实际用水量仅为资源蕴藏的１０％。农业灌溉是其主要耗水方式。西南五省（市、区）耕地约１６７００万亩（约１１１３万ｈｍ＾２）,有效灌溉面积占其中的４２％,人均有效灌面积仅０．４亩（约０．０４４８ｈｍ＾２）。今后粮食生产的潜力在于进一步发展水利工程,提高有效灌溉面积。在未来的１０年可增加灌面近１５００余万亩,约可增加粮