环保型煤炭开采与利用技术--煤炭地下气化

介绍了煤炭地下气化技术的开发与应用，相比传统煤炭开采燃用技术，煤炭地下气化实现了煤炭清洁开采与利用，指出煤炭地下气化技术是环保型开采与利用技术，应用积极推广利用。     

碱性物质中和法在处理煤矿废水中的应用

在地下煤矿开采的地区，大都伴之有地下水排放。在面临全球性淡水缺乏的形势下，煤矿排放废水却作为污染源，日夜注入河床，致使环境保护部门为之大伤脑筋，而且各煤矿也为煤矿排放废水的治理，付出了很大的经济代价。因此如何解决煤矿排放废水达标排放的问题，使其能作为矿产资源和水资源得到再利用，解决即将到来的水荒危机就成为了本次论文讨论的重点。     

典型干煤粉气流床气化全过程污染管控分析

现代煤化工是以传统煤化工为基础,以煤炭的清洁利用和高效转化为定位的一种新型产业。“十三五”期间,我国现代煤化工整体仍处于示范发展阶段。典型干煤粉气流床气化技术是现代煤化工行业的重要技术,对该技术进行了介绍,通过对其全过程污染物排放特征分析,从源头减排角度,提出了优化原辅材料选用,优化工艺结构设计和设备选型的建议;从过程控制角度,提出了过程控制工艺运行关键参数,强化日常巡检和优化污染源排放方式的建议;从末端治理的角度,列出了主要污染物排放环节对应的可行治理技术。     

褐煤地下气化过程中铅和砷的迁移规律的研究

在煤炭地下气化模型试验的基础上,研究了褐煤原煤及其气化产物中的铅和砷的含量和分布,进行了铅和砷的质量平衡计算,并分析了其析出的反应机理.实验结果表明,铅在原煤中以残渣态23.07%、碳酸盐和铁锰氧化物结合态53.96%、硫化物结合态22.96%存在,而砷则以残渣态47.73%、有机结合态7.95%、硫化物结合态40.90%存在.在气化过程中63.65%的铅和56.23%的砷残存在地下煤灰中,1.15%的Pb和6.62%的As转化到煤气冷凝水中,35.20%的Pb和37.15%的As转化到煤气中.     

煤气化炉渣研究现状及利用技术展望

煤气化技术的应用是我国能源战略的重要一环,但同时也会产生大量的煤气化炉渣,亟需研究可批量消纳的资源化利用技术。煤炭灰分中各种矿物相在气化炉内会随温度发生变化,通过对该变化的研究和总结,描述了煤炭灰分中各种矿物相在气化炉内的物化反应过程,并指出煤炭灰分对煤气化炉渣的最终形态特点具有决定性的影响;对煤气化炉渣中残碳的组成及其变化特点的研究表明,残碳对煤气化炉渣的最终利用途径具有重要影响;此外,通过分析煤气化炉渣利用技术研究现状,指出建材化利用技术和掺烧循环流化床原料技术是目前的主流途径;最后,展望了煤气化炉渣利用技术的发展方向,并提出了煤气化炉渣用于混凝土和水泥原料以及井下回填的技术途径。     

Investigation of polycyclic aromatic hydrocarbons from coal gasification

The hazardous organic pollutants generated from coal gasification, such as polycyclic aromatic hydrocarbons(PAHs), are highly mutagenic and carcinogenic. More researchers have paid particular attention to them. Using air and steam as gasification medium, the experiments of three kinds of coals were carried out in a bench-scale atmospheric fluidized bed gasifier. The contents of the 16 PAHs specified by US EPA in raw coal, slag, bag house coke, cyclone coke and gas were measured by HPLC to study the contents of PAHs in raw coal and the effects of the inherent characters of coals on the formation and release of PAHs in coal gasification. The experimental results showed that the distributions of PAHs in the gasified products are similar to raw coals and the total-PAHs content in coal gasification is higher than in raw coal(except Coal C). The totaI-PAHs contents increase and then decrease with the rise of fixed carbon and sulfur of coal while there has an opposite variation when volatile matters content increase. The quantities of PAHs reduce with the increase of ash content or the drop of heating value during coal gasification.     

On the mitigating environmental aspects of a vertical well in underground coal gasification method

Mitigation and Adaptation Strategies for Global Change - Underground coal gasification (UCG) is an energy production pathway in underground coal deposits with the potential advantage of decreasing...     

民用清洁煤技术的定量评价与筛选

选用合适的民用清洁煤技术是提高居民生活用煤能源利用效率、减少环境污染的重要途径之一,本文利用笔者提出的清洁煤技术定量评价方法对民用清洁煤技术进行了定量评价与筛选,评价结果表明,在标准状态下各种民用适用清洁煤技术的单位综合成本分别为选煤48元/GJ,民用型煤45.73元/GJ,炼焦制气28.53元/GJ,加压气化联产甲醇54.73元/GJ,加压气化联产油蜡50.71元/GJ,两段炉气化88.66元/GJ,直立炉气化38.84元/GJ,其中炼焦制气是单位综合成本最小的民用清洁煤技术．敏感度分析表明,煤气化将是民用清洁煤技术的主要发展方向     

鲁奇煤气化工艺低温煤焦油的组成研究

利用液-液提取分离和制备液相色谱分离相结合的预分离程序、GC-MS结合保留指数的定性方法,分析研究了鲁奇煤气化工艺低温煤焦油的化学组成,推测鉴定出12大类共400余种化合物,并对其中脂肪烃、PAH、NPAH和酚类化合物进行了定量分析,讨论了鲁奇低温煤焦油的组成特点.     

富含硅铝的工业灰渣合成沸石的研究进展

沸石是一系列多孔硅铝酸盐材料的统称,因其具有较高的阳离子交换能力,作为吸附材料广泛应用于污水的净化和催化合成化学品等多个领域。燃煤灰渣、煤气化灰渣、铸造灰渣等工业灰渣含有大量的Si、Al元素,可以作为合成沸石的主要原料,达到资源化利用这些固体废物的目的。分析了燃煤灰渣、煤气化灰渣和铸造灰渣的形成和来源,对比三者的化学成分发现,燃煤灰渣的化学成分含量表现为SiO₂>Al₂O₃>Fe₂O₃>CaO,煤气化灰渣的烧失量比较高,可达36.1%,铸造灰渣的硅铝比显著高于煤气化灰渣和燃煤灰渣。目前,3种灰渣中,燃煤灰渣的研究和利用比较多,而铸造灰渣和煤气化灰渣相对较少;铸造灰渣的Al₂O₃和SiO₂的总含量比较高,烧失量和金属氧化物含量较低,是一种合成沸石的优质原料,可合成高品质沸石;煤气化灰渣的残碳含量比较高,在考虑煤气化灰渣Si、Al回收和利用的同时,还应充分考虑其残碳的资源化利用。

     

Fe3+、PO43-在煤气化废水处理中的应用

针对煤气化废水的特点,通过投加Fe3 、PO43-的方法来强化多阶段水解-好氧工艺处理煤气化废水的能力,不加Fe3 、PO43-时,CODcr总去除率为78 88%,出水CODcr仍高达931mg/l,当投加Fe3 、PO43-后,出水CODcr降到245mg/l,去除率达到93 93%。     

Sequentially coupled flow-geomechanical modeling of underground coal gasification for a three-dimensional problem

Underground coal gasification (UCG) has been identified as an environmentally friendly technique for gasification of deep un-mineable coal seams in situ. This technology has the potential to be a clean and promising energy provider from coal seams with minimal greenhouse gas emission. The UCG eliminates the presence of coal miners underground hence, it is believed to be a much safer technique compared to the deep coal mining method. The UCG includes drilling injection and production wells into the coal seam, igniting coal, and injecting oxygen-based mix to facilitate coal gasification. Produced syngas is extracted from the production well. Evolution of a cavity created from the gasification process along with high temperature as well as change in pore fluid pressure causes mechanical changes to the coal and surrounding formations. Therefore, simulation of the gasification process alone is not sufficient to represent this complex thermal-hydro-chemical–mechanical process. Instead, a coupled flow and geomechanical modeling can help better represent the process by allowing simultaneous observation of the syngas production, advancement of the gasification chamber, and the cavity growth. Adaptation of such a coupled simulation would aid in optimization of the UCG process while helping controlling and mitigating the environmental risks caused by geomechanical failure and syngas loss to the groundwater. This paper presents results of a sequentially coupled flow-geomechanical simulation of a three-dimensional (3D) UCG example using the numerical methodology devised in this study. The 3D model includes caprock on top, coal seam in the middle, and another layer of rock underneath. Gasification modeling was conducted in the Computer Modelling Group Ltd. (CMG)’s Steam, Thermal, and Advanced processes Reservoir Simulator (STARS). Temperature and fluid pressure of each grid block as well as the cavity geometry, at the timestep level, were passed from the STARS to the geomechanical simulator i.e. the Fast Lagrangian Analysis of Continua in 3 Dimensions (FLAC3D) computer program (from the Itasca Consulting Group Inc.). Key features of the UCG process which were investigated herein include syngas flow rate, cavity growth, temperature and pressure profiles, porosity and permeability changes, and stress and deformation in coal and rock layers. It was observed that the coal matrix deformed towards the cavity, displacement and additional stress happened, and some blocks in the coal and rock layers mechanically failed.     

Analysis of organic compounds in coal gasification wastewater

A procedure for analysis of organic pollutants in coal gasification wastewater was developed, including a series extraction steps at different pH, followed by LC separation or resin adsorption, then analyzed by GC or GC/MS. More than 200 organic pollutants in 22 categories were determined. CH2CL2 extraction at NaHCO3 presence was used to separate carboxylic acids with phenolic compounds in aqueous. Derivatization with acetic anhydride was used for analyses of mono-, di-, poly-hydroxyl phenolic compounds. 21 mono-hydroxyl phenols and 13 di-hydroxyl phenols were determined from the coai gasification wastewater samples. Derivatization with BF3-CH3OH was used for analysis of carboxylic acid. 17 mono-carboxyl, 4 di-carboxyl acids and 6 aromatic acids were determined from coal gasification wastewater samples.     

高硫煤热解部分气化过程中硫的变迁行为

针对3种不同煤阶的高硫煤,分别在固定床反应器中考察其固定升温速率下原煤热解和半焦在不同温度下的水蒸气部分气化过程中的硫变迁行为.研究过程分为热解和部分气化2个子过程.结果表明,热解过程中大同、义马和西山煤总脱硫率分别为41%、42.5%和23.1%,其过程中FeS₂完全转化为FeS,不稳定的有机硫部分析出,硫从固相中的脱除大于碳的转化,硫在气相中得到富集;在部分气化过程中,对于大同和西山煤,半焦中硫含量可有效降低,脱硫率分别提高26.47%和19.37%,其中无机硫化物(FeS)易于气化析出,其析出程度随温度升高而增大.但对义马煤焦部分气化结果证实:在700℃气化时,总脱硫率可提高24.60%,在高于700℃气化时,有利于碱土金属与H₂S反应进行,同时由于碳骨架的气化速度加快,降低了其有机质对灰分固硫行为的传质阻力,所以灰分中碱土金属的固硫作用增强,使得半焦中硫含量增加,脱硫率与碳转化率的差值下降,不利于硫的脱除.     

Enhanced anaerobic biodegradability of real coal gasification wastewater with methanol addition

Coal gasification effluent is a typical refractory industrial wastewater with a very poor anaerobic biodegradability due to its toxicity.Methanol was introduced to improve anaerobic biodegradability of real coal gasification wastewater,and the effect of methanol addition on the performance was investigated in a mesophilic upflow anaerobic sludge bed reactor with a hydraulic retention time of 24 hr.Experimental results indicated that anaerobic treatment of coal gasification wastewater was feasible with the addition of methanol.The corresponding maximum COD and phenol removal rates were 71% and 75%,respectively,with methanol concentration of 500 mg COD/L for a total organic loading rate of 3.5 kg COD/(m3 ·day) and a phenol loading rate of 0.6 kg/(m3 ·day).The phenol removal rate was not improved with a higher methanol concentration of 1000 mg COD/L.Substrate utilization rate (SUR) tests indicated that the SURs of phenol were 106,132,and 83 mg phenol/(g VSS·day) at methanol concentrations of 250,500,and 1000 mg COD/L,respectively,and only 45 mg phenol/(g VSS·day) in the control reactor.The presence of methanol could reduce the toxicity of coal gasification wastewater and increase the biodegradation of phenolic compounds.     

Study on an environmental-friendly and high-efficient fuel cell energy conversion system

The kinds and the distribution of the coal in China are investigated.The results indicated that the 80% coal in China is used by the method of the coal gasification.The possibility of utilization and development of the fuel cell power plant in China is analyzed.A combined cycle generation system is designed.Its net electrical efficiency is about 55%(LHV),which is higher than that of the fire power plant.So it is environmental-friendly and high-efficient generation mode.     

氯元素对烟气中汞的形态和分布的影响

采用化学热力平衡分析方法研究了在煤燃烧在气化过程中产生的瀵气里痕量元素汞的形态及分布，在一个大气压下，400K－2000K温度范围里，研究了汞－煤系统和汞－煤－氯系统中汞在还原性气氛和氧化性气氛的烟气中的化学形态和分布，着重探讨了煤中的氯元素对汞在烟气中的形态和分布的影响，化学热力平衡分析结果表明，在煤燃烧和气化的最高温度区域里，单质汞是示是主要形式，少量的氯元素可以大大地增强汞元素的蒸发;在气化的还原性气氛烟气中，汞的主要形式是单质汞，在氧化性气氛的燃煤烟气中随着在烟气中温度的降低，单质汞将发生化学反应而生成氯化汞；烟气中氯元素的含量越大，氯化汞作为稳定相的温度范围越宽。     

碱性物质中和法在处理煤矿废水中的应用

凡是有地下煤矿开采的地区,都伴之有地下水排放.在面临全球性淡水缺乏的形势下,煤矿排放废水却作为污染源,日夜注入河床,致使环境保护部门为之大伤脑筋,而且各煤矿也为煤矿排放废水的治理,付出了很大的经济代价.因此如何解决煤矿排放废水达标排放的问题,使其能作为矿产资源和水资源得到再利用,解决即将到来的水荒危机就成为了本文讨论的重点.     

镁砂窑的黑烟治理

本文介绍了乡镇镁砂工业的主干装备———镁砂窑轻烧镁砂由燃煤改燃煤气的新工艺、煤的气化原理及反应顺序、镁砂窑改变燃料的比较计算、简易煤气发生炉的构造和煤气燃烧用的空气量计算等，并对镁砂窑采用煤气燃烧工艺后所产生的综合效果，作了简单的评价     

煤矿开采区地下水环境影响评价方法与治理研究

针对煤矿开采对地下水污染的问题,首先分析了煤矿开采对地下水污染的影响因素,然后通过对研究区域地下水污染物组分的分析,考虑各种评价方法的优缺点,采用模糊综合评判法,对煤炭开采对地下水的污染做出了比较合乎实际的评价。最后,对防治煤矿开采对地下水污染工作提出一些建议。