Comprehensive Evaluation of Gas Extraction System Reliability Based on Analytic Hierarchy Process

为了提高矿井瓦斯抽采效果,建立了瓦斯抽采系统安全可靠性评价体系,用层次分析法对指标权重进行了计算,并通过了指标一致性检验;应用层次分析综合评价法建立了其评价模型,对大水头矿瓦斯抽采系统进行了实例评价,根据综合评价结果,判断矿井瓦斯抽采系统是否满足安全生产的要求,提出其需要整改的薄弱环节,确保矿井安全生产。     

The Analysis of Seam Pressure Released Effect in Protection Layer Mining of Kilometer Deep Shaft

平顶山天安煤业股份有限公司十二矿己15-31010工作面垂深为1 015～1 130 m,为煤与瓦斯突出煤层,采用开采解放层己14煤层预抽瓦斯是解决己15煤层煤与瓦斯突出的关键技术,因此,针对深部保护层开采过程中下部煤层的卸压效果需进行深入分析。首先根据实际地质条件建立了三维数值模型,计算了己14煤开采过程中下部己15煤层的应力分布。计算结果显示,下部己15煤层在上部保护层开采过程中压力先升高后降低,在采面通过40 m后煤层压力降低至小于1 MPa;但在采空区外侧集中应力区,最大应力值高达42 MPa。现场监测数据显示,采空区下方煤层巷道瓦斯浓度显著增大,但外侧煤层巷道瓦斯浓度变化较小,在上方采面通过40 m后,巷道变形趋于稳定,煤层得到充分卸压。综合数值计算结果和现场监测数据可知,深部近距离保护层开采可以显著降低下部煤层压力,释放煤层瓦斯,但由于集中应力的影响,难以释放位于采空区边缘的下部煤层瓦斯。     

煤矿瓦斯变压吸附提纯甲烷的研究进展

因煤层赋存条件和抽采技术水平限制,导致煤矿抽采瓦斯中甲烷(CH₄)浓度偏低,而直接排空处理将造成清洁能源浪费和温室效应加剧,因此研究煤矿瓦斯中CH₄提纯利用途径将对煤炭行业节能减排具有重要意义.相比于其它气体分离提纯技术,变压吸附分离技术具有操作简单、能耗低及工业化成熟度高等诸多优势.本文将以变压吸附分离技术提纯CH₄为核心,重点论述了近些年吸附剂类型、吸附分离机制和分子动力学模拟等方面的研究进展,然后列举变压吸附提纯CH₄工艺优化及工业大规模应用实例,最后结合基础研究和工程应用总结展望了变压吸附技术在CH₄提纯领域的发展前景,并指出低浓度瓦斯(<10%CH₄)提纯及真空变压吸附技术是为进一步提升煤矿瓦斯利用率而亟需攻坚克难的主要研究方向.     

醋酸钯和四氯对苯醌催化氧化低浓度煤矿瓦斯制甲醇（英文）

利用自制的实验系统进行了醋酸溶液中低浓度瓦斯催化氧化制甲醇研究。实验结果表明,以Pd(OAc)_2为催化剂,反应体系中添加对苯醌或四氯对苯醌可改善甲烷活化环境,四氯对苯醌对瓦斯催化氧化过程的作用效果好于对苯醌。四氯对苯醌用量、反应压力和反应温度对瓦斯催化氧化具有重要影响。甲醇生成量随四氯对苯醌用量、反应压力和反应温度升高而增加。CH_3OH是通过反应过程中产生的H_2O_2与CH_4相互作用形成的。CH_3COOCH_3一部分是由Pd~(2+)直接氧化CH_4得到的;另一部分是由CH_3OH与反应溶剂CH_3COOH通过酯化反应形成的。     

醋酸钯和四氯对苯醌催化氧化低浓度煤矿瓦斯制甲醇

利用自制的实验系统进行了醋酸溶液中低浓度瓦斯催化氧化制甲醇研究。实验结果表明,以Pd(OAc)₂为催化剂,反应体系中添加对苯醌或四氯对苯醌可改善甲烷活化环境,四氯对苯醌对瓦斯催化氧化过程的作用效果好于对苯醌。四氯对苯醌用量、反应压力和反应温度对瓦斯催化氧化具有重要影响。甲醇生成量随四氯对苯醌用量、反应压力和反应温度升高而增加。CH₃OH是通过反应过程中产生的H₂O₂与CH₄相互作用形成的。CH₃COOCH₃一部分是由Pd²⁺直接氧化CH₄得到的;另一部分是由CH₃OH与反应溶剂CH₃COOH通过酯化反应形成的。     

中变质煤小分子相对煤的吸附及渗流特性影响

为研究煤中小分子对煤的瓦斯吸附及流动特性的影响,采用四氢呋喃溶剂萃取煤中可溶有机小分子,得到萃取后煤样(残煤)。对原煤和残煤分别进行甲烷等温吸附、解吸实验和径向渗流实验;同时,采用氮气吸附法测试了它们的孔隙结构参数。结果表明,残煤的饱和吸附量a值低于原煤,吸附常数b值增大,萃取小分子降低了煤对甲烷的吸附能力,提高了低压段(<4 MPa)煤对甲烷的解吸速率;原煤的孔体积和平均孔径高于残煤,比表面积和微孔孔体积却减少;萃取后,煤粒表面传质阻力和扩散阻力均减小,残煤甲烷解吸速率和解吸量均高于原煤;同一渗流条件下,残煤的渗透率明显高于原煤。分析认为,煤中部分小分子被溶解后,煤孔隙结构的改变,降低了煤对瓦斯的吸附能力,减小了甲烷在煤粒中的内外扩散阻力,扩大了瓦斯在煤中的流动通道,改变了煤层储运特性,为煤储层的化学增透提供依据。     

低浓度甲烷流向变换催化燃烧的研究

甲烷在煤矿工业中被称作为瓦斯,在富含甲烷的矿井中甲烷的体积分数为0．1％～1．0％,在煤矿开采过程中甲烷的体积分数达到5％～15％就会造成瓦斯爆炸。如果能够将煤矿中的甲烷抽取出来利用,不但可以减少矿难事故的发生,而且能够提供更多可利用的清洁能源。因此,如何将此低品位的资源转化为可利用的能源,具有重要的研究价值。另外,甲烷的温室效应是CO2的21倍。因此,将伴随某些工业生产以及石油开采过程产生的低浓度甲烷直接排放到大气中,势必会造成严重后果。     

矿用密闭堵漏材料的研究现状

矿井漏风是煤矿通风工作的一大隐患,易引发瓦斯事故及发生火灾,严重威胁矿井安全生产。总结了目前我国矿井普遍采用的密闭堵漏灌浆材料,特别是有机高分子灌浆材料,分析了各材料的特点及其局限性,并对密闭材料未来的发展趋势做了简单预测。     

十二烷基硫酸钠对甲烷水合物生成过程影响研究

根据甲烷水合物含气率高、分解速度慢等特性,提出利用高压注水技术和表面活性剂促进作用促使矿井瓦斯水合化以预防煤与瓦斯突出的思路。进行了3·6~12℃、7·82~12·26MPa条件下两种浓度体系(10mmol/L和0·3mmol/L)中十二烷基硫酸钠(SDS)对甲烷水合物作用效果的实验研究,结合水合物诱导时间、生成速度及含气率等计算对实验数据进行了分析,并运用表面张力法测得8℃时SDS溶液的临界胶束浓度(CMC)为2·5mmol/L。结果表明,高浓度体系对水合物生成速度、含气率的影响较之低浓度体系的更强,但是低浓度体系中水合物生成的诱导时间却较短,表面活性剂溶液浓度超过其CMC后对水合物的生成影响显著。     

加拿大合成原油瓦斯油裂解反应规律与产物生成机理

利用小型固定流化床实验装置研究了加拿大合成原油重瓦斯油(HGO)和轻瓦斯油(LGO)的催化裂解性能和热裂解性能。HGO和LGO催化裂解总低碳烯烃(乙烯+丙烯+丁烯)产率在660℃附近达到最大值,分别为33.8%和35.6%。HGO和LGO热裂解反应程度很大,700℃的转化率分别为66.7%和76.3%。HGO热裂解总低碳烯烃的产率在680℃达到最大值27.9%。通过对比分析催化裂解与热裂解气体产物产率的比值发现,催化剂的加入促进了乙烯和液化气的生成,同时抑制了甲烷和乙烷的生成。研究结果揭示了小分子烃类的生成机理,甲烷和乙烷主要是自由基反应的产物,乙烯和液化气是自由基反应和正碳离子反应的共同产物。     

汽爆技术促进中药资源高值化利用

汽爆技术在中药资源高值化利用中发挥的作用正在逐渐体现:汽爆处理打破中药植物细胞壁的屏障结构,有利于有效成分的分离提取;汽爆过程物料自体水解发生去糖苷化作用使天然植物中的苷元与糖基分离,提高苷类物质提取和分离效率;汽爆应用于中药炮制和中药脱毒有高效、快速和避免有效成分流失等优点;汽爆处理有利于中药非药用组分如纤维素、半纤维素等的有效分离和利用,联产乙醇、丁醇等能源和化工产品。本文对汽爆技术在中药资源高值化利用中的研究进展进行了综述。     

Analysis of the effect mechanism of water and CH4 concentration on gas explosion in confined space

In order to study the effect of water and CH₄ concentration on gas explosion, a 20L spherical explosive device was used to carry out a water-containing gas explosion experiment, and the explosion simulation was carried out with CHEMKIN-PRO, the mechanism of water on gas explosion was analyzed from the perspective of free radicals and energy. The results showed that the upper limit of gas explosion, maximum explosion pressure and temperature decreased significantly with the increase of water content. The higher the concentration of CH₄, the more obvious the inhibitory effect of water on gas explosion pressure, and the optimal explosion concentration of CH₄ decreased with the increase of water content. As the water content and CH₄ concentration increase, the residual CH₄ content increases after the explosion, the O₂ content decreases, and the CO content produced increases. When the CH₄ concentration is lower than the optimal concentration, water promotes the formation of CO₂ to a certain extent; when the CH₄ concentration is higher than the optimal explosive concentration, the CO₂ content decreases with the increase of water content. Overall, water inhibits methane explosion, the addition of water on the one hand reduces the concentration of active free radicals H, O, OH, on the other hand, it interferes with the generation of gas explosion energy and consumes the kinetic energy of the gas explosion flame shock wave through heat absorption, thus inhibiting the intensity of gas explosion.     

H2,CO,CH4多元爆炸性混合气体支链爆炸阻尼效应

对多元爆炸性混合气体爆炸的阻尼效应,进行了比较系统的研究,实验表明：“惰性气体”N2,CO2与水蒸汽对多元混合气体支链爆炸具有一定的抑制作用;甲烷与石油液化气对含H2易爆混合气体支链爆炸具有明显的阻尼效应．这对指导支链燃烧与支链爆炸的实践,关于工业尾气与废气的安全回收,有关爆炸性混合气体的置换技术的改进,以及工业与矿井混合气体爆炸事故的预防,具有重要的现实意义与理论价值．     

Explosive limits and its container factors of polybasic explosive mixture gas containing H<Subscript>2</Subscript>, CH<Subscript>4</Subscript> and CO

Explosive characteristics of polybasic explosive mixture gas are systematically researched. Over 28000 experimental data have been obtained from 1278 effective experiments. The paper probes into the concentration explosive limits and the container factors of polybasic explosive mixture gas which contains H2, CH4 and CO. It has worked out the sufficient and necessary condition for branch-chain explosion and the unified expression of the probability of the heterogeneous chain termination. Experiments indicate that the concentration explosive limits of polybasic explosive mixture gas (H2, CH4, CO) relate to many factors. They enlarge with the augmentability of the container (linear size, geometric shape, and flame spread direction). This will be of great significance to guiding the revision of related industrial safety targets, reclaiming and reusing related industrial tail gas and waste gas, taking precautions against the explosion hazard of mixture gas in correlated industry and mines, and applying the br     

(H_2+CO+CH_4+Air)多元爆炸性混合气体爆炸形态与波形的区划

对H2,CO,CH4多元体系支链爆炸的爆炸特性与形态进行了系统的研究.探索了浓度爆炸极限、爆炸形态与波形及其影响因素;测定了爆炸危险度、火焰蔓延极限、最小点火能等爆炸特性参数;根据爆炸形态与波形的不同,提出了爆炸形态与波形的新区划理念,在爆炸极限内,可进一步区划为上下限冷焰区、上下限爆燃区、爆轰区、下爆燃向爆轰转化区等6个爆炸形态区,并探讨了不同爆炸形态压力波的发展机制,对进一步研究相关的多元支链爆炸体系,促进多元支链爆炸理论的发展,具有一定的理论价值.实验测得的爆炸危险度、火焰蔓延极限、最小点火能等特性参数,与引进‘关键组分'的概念,对预防混合气体支链爆炸事故的发生,指导防爆电气设备与阻火器设计,修订相关工业的安全指标,指导支链燃烧与支链爆炸的实践,具有积极的现实意义.     

Controlling the Combustion,Exploding, and Detonation of Gases by Means of Chemical Kinetics

Russian Journal of Physical Chemistry A - Ways are considered of preventing fires and explosions of methane–air mixtures in coal mines and elsewhere, the ignition and explosion of...     

Photochlorination of tetramethylsilane and hexamethyldisilane in the gas phase

Preliminary studies of the reaction of chlorine with tetramethylsilane and hexamethyldisilane in the gas phase show that the photochlorination of tetramethylsilane is complex, giving different products from the corresponding reaction in solution and having an explosion boundary. At pressures below the explosion boundary the main products are ethylene, hydrogen chloride, dimethylchlorosilane, and more highly chlorinated methylsilanes. Above the explosion boundary main products after explosion are methane, acetylene, ethylene, hydrogen chloride, and silicon tetrachloride. Hexamethyldisilane reacts rapidly with chlorine in the dark, as it does in solution, forming mainly trimethylchlorosilane along with similar products to those found with tetramethylsilane. Subsequent photochlorination of trimethylchlorosilane follows a similar course to that of tetramethylsilane in the gas phase. Tentative mechanisms involving “hot” molecules are suggested.     

超临界水中煤与聚苯乙烯的共液化研究

在间歇式高压反应装置中,研究了兖州烟煤与塑料聚苯乙烯(PS)在超临界水中的共液化,考察了水/物料比(质量比10～30)、反应温度(360℃～430℃)和塑料添加量(10%～40%)对煤液化转化率及产物收率的影响.结果表明,随着水/物料比的增加,煤液化转化率先升高,之后变化不大;油气产率则呈上升的趋势.反应温度高于420...     

Experimental investigation on wetting mechanism for coal dust with different metamorphic degree based on infrared spectrum and 13C-NMR

Respirable coal dust accounts for heart and respiratory diseases of coal miners such as asthma, pneumoconiosis, and black lung disease. What is more, coal dust explosion seriously affects coal mine safety production and coal miners' life safety. Generally, dust suppressants are commonly applied in coal mines. However, current dust suppressants are not working effectively. To develop a better dust suppressant, we attempt to explore the factors affecting the wettability of coal dust under different metamorphic levels from the essence of coal dust wetting mechanism in this paper. Specifically, we use Fourier transform infrared (FTIR) spectroscopy and nuclear magnetic resonance (NMR) to reveal the microstructure of coal from two aspects of functional group and carbon skeleton structure and obtain the micro information of the surface functional group types, quantity, and carbon structure of coal with different degrees of metamorphism, as well as the change rule of functional group of coal sample with coal rank and the law of carbon increase and deoxidization of coal metamorphism. After that, we acquired the structural parameters of coal by the NMR experiments and fitted the quantitative mathematical relationship between the microstructure parameters and wettability of coal through SPSS and ORIGIN software. Finally, this paper constructs an evaluation model for the influencing factors of coal dust wettability, explains the influence degree of different coal dust structure on coal dust wettability, improves the coal dust wettability mechanism, and provides more quantitative research ideas and methods for the control of coal dust.     

固体热载体热解淮南煤实验研究

自制处理量为1 kg煤的间歇式固体热载体热解装置,以淮南烟煤为原料,石英砂作热载体,对该煤进行热解特性评价实验。考察了热载体初始温度700 ℃～900 ℃、反应 4 min～16 min、煤粒径及热载体与煤的质量比5～9对热解产物产率和性质的影响。结果表明,提高热载体初始温度,气、液产率增加;延长反应时间和提高热载体比例,气体产率有所增加;热载体初始温度对热解气组成影响显著。提高热载体与煤的质量比和热载体初始温度,可以抑制半焦对热解反应器内壁的黏附。