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天然气水合物——未来的新能源 总被引:19,自引:0,他引:19
现有资料表明,全球石油和天然气的后备资源还能维护40余年,因此科技专家将天然气水合物列为未来的新能源。在世界各海域目前已发现天然气水合物矿区82处,据地质学家估算,各海区天然气水合物中甲烷的碳总量是全球所有石油、天然气和煤的碳总量的2倍。广州海洋地质局对南海北部陆坡区开展了天然气水合物的调查,高分辨率地震调查资料显示,在南海北部陆坡区存在天然气水合物明显的地球物理标志。 相似文献
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新型蓄冷工质——异丁烷水合物生成特性的实验研究 总被引:3,自引:0,他引:3
为探讨新型蓄冷工质--异丁烷水合物快速牛成的影响因素,利用自行设计的小型搅拌式水合物制备系统,在定容法实验条件下,比较不同水量、搅拌速率、初始冷媒温度、水样条件下水合物的生成特性.实验结果表明:水量为200mL时,有着较大的气液空间比,利于水合物的生成;适当的搅拌速率增加扰动,有效改善气一水体系传质力,利于水合物生成,但搅拌速率过大易使水合物分解;初始冷媒温度越低,过冷度越大,水合物生成量越多;历史水具有"记忆效应",诱导时间最短;相对于历史水和蒸馏水,水合物在自来水中总生成量不多. 相似文献
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基于雾流强化技术,在喷雾反应器中进行了CO_2水合物生成特性的实验研究,探讨了反应釜内温度、压力和夹套内冷却液温度以及缓冲气罐的使用等对CO_2水合物生成特性的影响。研究发现,与在静态条件下生成CO_2水合物相比,雾流强化过程中的压降幅度更大,CO_2水合物生成速率更快。喷雾法将水以喷雾的形式送入气体,使水颗粒与气体的接触程度明显提高。实验结果表明,在相同工况下,增置缓冲气罐时,CO_2水合物生成结束时间是20 min左右,而未使用缓冲气罐的是40 min左右。缓冲气罐的稳流稳压作用使CO_2气体均匀、稳定地进入雾化系统,增强雾化效果,使水合物生成速率提高一倍。研究结果为CO_2水合物的生成特性分析和工程应用提供了重要参考依据。 相似文献
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利用RC1e量热反应仪,采用在线分析技术,对四氢呋喃水合物形成的历程行为进行了研究。结果显示:四氢呋喃同水构成的二组分体系形成历经成核诱导、成核和生长过程,过程中温度和热量的变化,可以确定成核点。利用自行设计制造的天然气水合物模拟生成装置考察了添加抑制剂对水合物形成过程的影响。通过对比添加热力学抑制剂和动力学抑制剂条件下水合物的生成情况,得出普遍情况下热力学抑制剂可以将水合物的生成时间延缓3~5 h,而动力学抑制剂则在降低80%用量的情况下将水合物的生成时间延缓10 h以上。最后结合实验结果,对两种抑制剂的抑制机理进行了分析和预测。 相似文献
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天然气水合物泥浆制冷系统的换热器对于天然气水合物的开采非常关键。本文以天然气水合物自然状态下的存在条件为依据,分析研究不同类型的换热器,对钻探取样方法获取保真的天然气水合物岩矿心的影响,对相同换热面积的同轴套管式换热器和螺旋板式换热器在同种工况下的传热效率进行对比分析,采用传热计算、数值模拟和室内实验相结合的方法,证明在相同的换热面积和同种工况下,螺旋板式换热器的换热效率可以提高70%,在满足水合物钻探取样要求条件下,可以有效地节省资源。 相似文献
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天然气水合物广泛分布在大陆、岛屿的斜坡地带以及海洋和一些内陆湖的深水环境,基于双相多孔媒质理论,分析和研究在孔隙中天然气水合物发生相变过程引起的多孔介质物性的变化而导致的声波传播的改变,可以找出其中的变化规律,对于研究岩芯中的天然气水合物具有重要的理论意义和实际价值。在模拟岩芯中天然气水合物发生相变过程中,纵波和横波速度随着孔隙度的增大而减小;衰减随着孔隙度的增大而增大,这些结果表明了实验结果与理论结果基本吻合,并为进一步的实验工作打下了良好的基础。 相似文献
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在输送天然气过程中,易出现天然气水合物堵塞管道的情况,给天然气输送带来安全隐患。本文从天然气水合物的结构出发,研究天然气水合物的形成机理,并给出管道输送过程中天然气水合物的防治方法,保障天然气管道输送的安全。 相似文献
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水合物技术应用可归纳为分解应用和生成应用,本文就这两大应用方向对水合物进行了分类综述。从水合物分解角度,阐述了天然气水合物资源勘探开发、管道水合物解堵、水合物抑制防控等技术应用的研究进展;从水合物分解的逆过程(生成)角度,阐述了水合物储气、二氧化碳捕获与封存、海水淡化、溶液提浓、污水处理、混合气体分离、蓄冷等应用技术。同时论文结合气体水合物发展历程,概括了气体水合物技术在诸多领域的应用,指出了水合物技术发展取得的诸多成果,也提出了新形势下水合物发展所面临的问题,希望能为今后水合物技术的发展带来一定指导。 相似文献
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Experiments have been made on cool storage by evaporation of HFC-134a (CH2FCF3) or HCFC-123 (CHCl2CF3) brought into direct contact with water in a crystallizer, which was incorporated into a vapour-compression refrigerator loop. The degree of supercooling before the inception of gas-hydrate formation with HFC-134a was found to be reduced by the addition of powdery alumina or zinc or the addition of a surfactant to the water, while the addition of Pseudomonas fluorescens, a strain of ice-nucleating bacteria, showed no effect. The use of HCFC-123 instead of HFC-134a resulted in the formation of slush ice only; no sign of gas-hydrate formation was recognized. The reason for this is considered to lie in the molecular size of HCFC-123. 相似文献
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研究了组成及温度对水/环己烷/TX-100 正戊醇体系反相微乳液区的影响,选择合适组成的反相微乳液做为合成介质,制备了BaMnCeAl10O19-δ六铝酸盐催化剂,研究了制备条件对催化剂样品的比表面积、结构及甲烷燃烧催化活性的影响.结果表明,该体系反相微乳液区面积的变化受到组成和温度的影响,当n=3:2、温度为25℃时,体系的反相微乳液区最大.油相和硝酸盐加入量的不同对催化剂的活性、粒径以及比表面积有较大的影响,油相用量增加、硝酸盐混合溶液用量的减少有利于所制备活性的提高以及比表面积的增加.在油相用量较大(硝酸盐混合溶液用量较小)的条件下,制备出的催化剂活性最高,其T10%、T50%和T90%分别达到456、582和698℃. 相似文献
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《Advanced Powder Technology》2014,25(4):1227-1233
This paper reports an experimental study of the kinetics of methane hydrate formation in the presence of ionic surfactants with equal carbon chain length, such as sodium dodecyl sulfate (SDS), dodecylamine hydrochloride (DAH), dodecyltrimethylammonium chloride (DTAC) and N-dodecylpropane-1,3-diamine hydrochloride (DN2Cl). Methane hydrates were formed at 274 K with incipient gas pressure of 15 MPa in an unstirred isochoric/isothermal reactor containing aqueous solutions at different initial surfactant loadings. It was found that addition of DTAC had little effect on methane hydrate formation whereas SDS, DAH, and DN2Cl had pronounced promoting effects. This result coincides with the fact that the Krafft point of DTAC is below 273 K and those of SDS, DAH, and DN2Cl are near room temperature. At a given initial surfactant loading, the effectiveness of the surfactants for reducing the induction time of methane hydrate formation followed the order of SDS > DAH > DN2Cl. SDS also gave higher hydrate growth rates than DAH and DN2Cl. At 1000 and 2000 ppm, however, DN2Cl gave slightly higher final methane uptake than SDS. It was also found that during the nucleation or induction period, addition of SDS, DAH and DN2Cl instead of DTAC, considerably reduced methane mole fraction in the liquid phase. Possible promotion mechanisms of surfactants during the hydrate nucleation period were discussed. 相似文献
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One of the new approaches for capturing carbon dioxide from treated flue gases (post-combustion capture) is based on gas hydrate crystallization. The basis for the separation or capture of the CO(2) is the fact that the carbon dioxide content of gas hydrate crystals is different than that of the flue gas. When a gas mixture of CO(2) and H(2) forms gas hydrates the CO(2) prefers to partition in the hydrate phase. This provides the basis for the separation of CO(2) (pre-combustion capture) from a fuel gas (CO(2)/H(2)) mixture. The present study illustrates the concept and provides basic thermodynamic and kinetic data for conceptual process design. In addition, hybrid conceptual processes for pre and post-combustion capture based on hydrate formation coupled with membrane separation are presented. 相似文献
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There is substantial evidence that the oceans of the world will pose the most important challenges in the area of hydrate formation. This work indicates three areas of concern for hydrate formation in the ocean: (1) deposits of natural gas in ocean hydrates, which will serve as an energy resource and environmental concern in the next tnillenium, (2) a recent proposal for the ocean storage of carbon dioxide in the form of hydrates, and (3) the prevention of hydrate formation in ocean pipelines. To address such applications, fundamental knowledge on the site of hydrate formation was determined. Results are presented for quiescent, high-pressure experiments done in a sapphire tube to determine the site of hydrate formation in deionized water and in mixtures with amorphous silica and sodium dodecyl sulfate. Visual (microscope aided) results are presented for formation with a typical gas mixture and with carbon dioxide.Invited paper presented at the Twelfth Symposium on Thermophysical Properties, June 19–24, 1994, Boulder, Colorado, USA. 相似文献