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煤炭地下气化是对传统采煤技术的变革,气化炉选址是煤炭地下气化能否成功的先决条件。基于煤炭地下气化的研究进展和存在的问题,分析煤炭地下气化原理和气化炉选址的地质影响因素,重点分析煤级、煤层、地下水、围岩、构造等地质条件。结果表明:褐煤最适合地下气化;地下气化煤厚度应大于2 m、煤层倾角小于70°、埋深300~2 000 m适宜。同时,煤炭地下气化过程可能会对地下水造成污染,地下水涌入气化盘区也会导致气化失败;煤炭地下气化容易引起围岩破裂,造成地下水贯入气化区以及地表沉降;煤炭地下气化炉选址应避开构造复杂区域;地下气化可能会影响附近含水层微生物的活性,破坏地下生态环境系统。 相似文献
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为厘清影响煤炭地下气化的地质因素,构建科学的地质指标评价体系,对影响煤炭地下气化的七大类地质条件、41个次级地质指标进行了系统分析和分级量化,建立了地质选区指标体系;根据对选区的重要程度,将各地质指标分为基本地质指标（A）和关键地质指标（B）两类,基于这两大类指标,提出了两种新的煤炭地下气化有利区定量评价方法,精细型（A+B）和通用型（B）;利用专家打分法和层次分析法确定了这两种评价方法中所涉及到的地质指标权重;依据资源、开采技术、区域构造和环境四大类条件,厘定了评价结果的定性分级方案;综合定量评价和定性分级,提出了有利区优选的一般步骤,最终形成了一套完整的煤炭地下气化有利区评价技术体系.该评价技术体系的有效应用,可为煤炭地下气化科学选址和产业化进程推进提供重要理论支撑. 相似文献
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地下煤层气化的燃烧范围,气化燃烧热力影响边界、形态、方向,气化区冒落带的发展高度及气化煤层裂隙发育程度,是开展煤炭地下气化工程迫切需要解决的问题。基于煤炭地下气化工程试验区地震地质情况,从地震响应入手,在分析煤炭地下气化后地震波场响应特征的基础上,提出了运用高密度三维地震采集技术结合全三维地震属性解释技术,高精度识别煤炭地下气化燃烧范围、气化热力影响边界的方法。实际勘探成果表明,本方法地震成像清晰,预测精度高,与钻探结果吻合较好。 相似文献
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煤炭地下气化为我国清洁、低碳、安全、高效现代能源建设开辟新的途径。为研究华亭烟煤地下气化污染物的富集、分布规律,以评估华亭烟煤地下气化的环境影响因素,采用地下气化模拟实验平台系统,通过不同富氧—水气化实验、不同尺度煤样的热解实验,研究煤层气化过程中焦油及气化残留物中重金属元素的富集规律。结果表明:随着烟煤的尺度（块体大小）增加,烟煤热解焦油呈增加趋势,而焦油产率呈先增加后减小的趋势;烟煤在N2、CO2气氛中热解时,热解焦油中主要成分为酚类、萘类以及烃类污染物;气化后残留重金属Ni、Cr、Zn、Cu、As这5种元素在氧化区最为富集、还原区次之、干馏干燥区最不富集,而Hg在氧化区富集程度最高、干馏干燥区次之、还原区最次,Pb在还原区富集程度最高、氧化区次之、干馏干燥区最次;重金属元素残留程度由高到低依次为Zn、As、Hg、Cr、Ni、Cu、Pb。针对华亭矿区,煤层气化后应重点检测重金属元素Zn、As、Hg。在后期实际煤层气化生产阶段,应结合华亭矿区煤层特征及地下水特征,在项目选址、气化工艺等方面进行污染物防控。在当前生态环境保护形势严峻的当下,研究成果对煤炭地下气化开采的污染物处置和减排具有一定的指导意义。 相似文献
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叙述了钻探（ 钻孔） 技术在地下污染层勘查、核废物储埋库选址、地下污染层解污、地下污染物封隔、污水曝气处理和垃圾场甲烷气利用等方面的应用,列举了环境工程实例 相似文献
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煤炭地下气化技术(UCG)是一种潜在的煤炭利用新方法,对于缓解我国能源危机,保障国家能源安全,实现碳达峰碳中和的“双碳”目标具有重大意义,其探索研究一直受到世界各国的重视。针对UCG资源条件的适宜性、工艺技术的可行性、环境影响的可控性3个方面,综述了煤炭地下气化技术的发展现状,阐明了适合UCG技术的煤炭资源储量情况、地质选区选址技术的不同标准、气化工艺的发展历程与适用条件、影响气化实施的工程与环境因素。分析认为,UCG的地质选区技术多为定性分析特定地质条件下的有利区,缺乏定量化的指标体系和方法,并且主要针对浅部和中部煤层,评价体系有待完善,特别是多煤层地区和深部煤层的开发;环境因素对于UCG产业化发展的影响越来越大,将是未来研究的主要方向之一。 相似文献
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Sasol has been operating the Sasol–Lurgi fixed bed coal gasification process for more than fifty years, and with ninety seven units in operation still remains the world's largest commercial application of this technology. The combined operational and engineering expertise vested in Sasol represents a formidable capability in the field of coal and gasification science. Coal is a crucial feedstock for South Africa's unique synfuels and petrochemicals industry, and is used by Sasol as a feedstock to produce synthesis gas (CO and H2) via the Sasol–Lurgi fixed bed dry bottom gasification process.South Africa, as well as many other countries in the world, will for many years to come rely on its abundant coal resources for energy and specifically for the production of petrochemical products. Synthesis gas production through gasification is growing at a rate of approximately 10% per annum [Office of Fossil Energy, National Energy Technology Laboratory and the Gasification Technologies Council, 2000. Gasification: Worldwide use and acceptance. Contract DE-AMO1-98FE65271], indicating that gasification is definitely not a dying technology. The Sasol plants located in Secunda and Sasolburg (South Africa) gasify > 30 million tons per annum of bituminous coal to synthesis gas, which is converted to fuels and chemicals via the Fischer–Tropsch process. The production of chemicals is currently the dominant application for synthesis gas, followed by power generation, Fischer–Tropsch synthesis and gaseous fuels.Sasol–Lurgi gasifiers are extremely robust devices, and coal from sources with widely varying properties (e.g. ash content < 10% to as high as 35% or “brown coal” with moisture content of approximately 30%) can be gasified provided that certain operational changes are implemented. Other properties, like high caking propensity for example, require blending to acceptable levels and /or mechanical modifications. Interpretation of coal characterization data gives an indication of expected gasifier performance and the suitability of a specific coal source for Sasol–Lurgi Fixed Bed Gasification process. It is therefore critically important to gain an accurate and fundamental understanding of the properties and expected behavior of the targeted coal feedstock in order to (1) prepare a suitable conceptual flow scheme and (2) to maximize the eventual probability of success in any proposed gasification venture and (3) to optimize the operation and profitability of existing plants and (4) effectively address the environmental aspects.It is the view of the authors that fixed bed gasification technology has a bright future in the areas mentioned above and that Sasol has a unique role in the future application and commercialization of gasification technology globally. The unique skills of Sasol could however be complementary to those of other parties who share our view on the future of gasification and related technologies. 相似文献
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通过对江苏省煤炭资源特征及利用现状分析,在安全、高效、环保优先的前提下,建议选择新兴煤炭地下气化高新技术,开启江苏省煤炭资源开发利用的新模式,详细分析了采用煤炭地下气化高新技术开发利用江苏省煤炭资源的五大优点,为江苏省煤炭资源开发利用探求一条新路子。 相似文献
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Internationally there is considerable interest in utilizing hydrogen as an energy carrier. The use of hydrogen offers considerable potential benefits such as reducing greenhouse emissions, reducing urban pollution, increased energy security and increased efficiencies from the use of advanced energy conversion technologies.One of the most important questions when considering the development of a hydrogen economy is “where will the hydrogen come from?” Possible answers include electrolysis of water, steam reforming of methane and the gasification of coal. Given the high costs associated with electrolysis of water, and the increase in the cost of methane predicted over time, the gasification of coal is viewed by many as being the cheapest method of hydrogen production in the foreseeable future. These considerations are particularly relevant to New Zealand where gas supplies are dwindling but where there is sufficient coal to last for many centuries at present utilization rates. This, along with the current high international interest in hydrogen energy, has been recognized by the New Zealand Government in the form of a six-year [2002–2008] research project “Hydrogen Energy for the Future of New Zealand”.One important coal property that, in particular, determines the suitability of a particular coal for use in a fluidised bed gasifier is its reactivity towards the gasification reaction. It was found that a high percentage of New Zealand's coal resource is particularly well-suited towards fluidised bed gasification, reacting at anywhere between 0.9 to 1.75 times the rate of Australian brown coals. It was found the New Zealand lignites contained significant levels of organically bound calcium, which was shown to be responsible for not only the high reactivity of the New Zealand lignites, but also a product gas composition with higher than expected hydrogen concentrations. These findings are discussed along with their implications for the gasifier and gas clean-up design. 相似文献
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地下水资源在世界各国水资源中占有举足轻重的地位,对人类生存发展、维系生态系统健康发挥着重要作用。现阶段地下水污染日益严重,地下水环境背景值研究和污染风险评价对地下水污染防治工作具有重要意义。由于地下水污染影响因素复杂,地下水化学组分空间分布的非均质性、地下水样品采集的小样本问题与大尺度区域的高计算代价,都对传统的污染风险评价方法构成了极大挑战。机器学习作为人工智能的核心,已成为水文地质领域研究的前沿热点,通过智能高效的数据处理和挖掘,在地下水化学组分的分布、变化以及赋存机制等方向已得到探索和尝试。本文全面介绍了近年来在地下水污染研究方面应用的机器学习方法,涵盖了以聚类为主的非监督学习算法,以回归为主的监督学习算法,以提升算法效率为目标的混合算法,以及以神经网络为核心的深度结构算法,展示了不同类型算法在地下水污染研究方面的成果,详细归纳了各种算法的机理,对算法的技术优劣及适用方向进行了探讨;最后对机器学习在地下水污染方面的应用发展趋势进行了展望,建议探索高效集成学习模型,以弥补单一算法的不足,同时发展面向小样本的深度学习建模技术,提高地下水污染评价精度,拓展和丰富新方法新技术在地下水污染研究方面的应用。 相似文献
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地下水氮元素污染是一个全球性的环境问题,其来源和迁移转化特征是国内外研究的热点。文章以新疆塔城盆地80组地下水样品水化学组分测试结果为依据,研究塔城盆地地下水“三氮”污染特征。结果表明:塔城盆地地下水质量总体较好;对比2017年发布的地下水质量标准,深层承压水“三氮”均未超标;浅层地下水“三氮”污染较轻,“三氮”超标点零星分布于地下水的中下游冲洪积平原区,其中,NO3-N超标率最高,超标率为8.8 %;NO2-N和NH4-N次之,超标率均为1.3 %。沿着地下水流向,从山区到盆地中央的平原区,地下水污染逐渐变重。“三氮”重污染点主要分布在塔城市、额敏县及其周边地区。区内地下水污染点的分布与工矿企业污染源、污水处理厂、垃圾填埋场等大型污染源的分布具有一定的相关性。城市化进程中,生活污水的不合理排放是塔城盆地“三氮”污染的主要来源,而通过排污河流下渗是研究区地下水“三氮”污染的重要途径;氧化还原条件、pH值、包气带岩性结构、补径排条件等是“三氮”迁移转化及其空间分布的主要影响因素。 相似文献