我国气体水合物研究进展

介绍了制冷剂气体水合物作为理想空调蓄冷介质的基础研究结果,并对天然气水合物的研究和前景做了一些阐述。     

气体水合物蓄冷技术

通过对气体水合物蓄冷技术基本原理的描述，概括总结了迄今为止对氟里昂气体水合物蓄冷的研究现状和发展概况，揭示在实用空调蓄冷系统中气体水合物作为新的蓄冷技术的节能优势，指明了气体水合物蓄冷技术应用于空调系统中仍需解决或需引起注意的问题。     

季盐对气体水合物相平衡影响研究进展

季盐是一种高效的水合物生成添加剂,通常通过填充水合物笼达到改善水合物相平衡条件的效果。季盐对CH₄、CO₂等气体水合物相平衡条件的影响效果主要与季盐浓度有关。就甲烷水合物而言,同等相平衡压力条件下,TiPeAF和TiAAB对相平衡影响显著：添加了TiPeAF(0.315%)、TiAAB(0.438%)的体系,其相平衡温度分别比纯水体系高20 K和22 K;TBANO₃、TAAB、TAAC对相平衡影响甚微：其相平衡温度较添加TBAB、TBAC等季盐的体系低10 K。对于CO₂水合物,添加TiAAB的体系相平衡温度比纯水体系高29 K,添加TBAF体系的相平衡温度比纯水体系高26 K。此外,季盐与其他类型添加剂复配后对水合物的相平衡条件有更好的提升效果：相较于仅添加TBAB的体系,TBAB(0.05%)和NaCl(0.03%)的复配体系可以使水合物相平衡温度再升高10 K。     

新能源气体水合物及其发展应用前景

随着能源紧缺问题的加剧，科学家们把更多的目光投向了新能源的开发和利用。20世纪中期，科学家发现了天然气体水合物这一新的替代能源，并不断地对此物质进行研究和探索，希望人类能尽早地真正生产和利用气体水合物，缓解人类社会能源短缺的问题。文章介绍了气体水合物的组成结构、形成和分解机理、天然水合物在地球上的蕴藏分布和开采情况及其在工业上的应用前景，并对气体水合物的研究方向提出了看法。     

环戊烷纳米乳液水合物蓄冷特性试验研究

为促进静态条件下水合物蓄冷的快速进行,以吐温80、司盘80作表面活性剂,正丁醇作助表面活性剂,通过高速搅拌制备了环戊烷纳米乳液。研究了纳米颗粒粒径和纳米流体浓度对水合物蓄冷过程的影响,结果表明纳米乳液强化了水合物的形成过程,在静态条件下成功实现了环戊烷纳米乳液快速水合蓄冷。     

不同结构气体水合物稳定性的分子动力学研究

气体水合物是一种包络状晶体,在能源勘探、二氧化碳捕集和封存、海水淡化及空调蓄冷等领域均有潜在的应用价值.稳定性研究能够确定水合物稳定存在的热力学区间,方便水合物在各个领域内应用.然而,通过宏观实验研究很难精确的控制和分析水合物的稳定性及分解特性.本文采用分子动力学模拟,在微观角度研究了构型不同、客体分子不同的情况下,气体水合物稳定性的差异,从径向分布函数、均方位移、F3序参数三个方面进行了探讨.发现对于CO2气体水合物,Ⅰ型结构更加稳定;CO2和环戊烷二元水合物的稳定性优于CO2水合物,为水合物的宏观实验研究和工程应用积累了理论基础.     

利用水合物法分离捕集二氧化碳研究进展

我国是以煤炭为主要能源的国家,面临着严峻的碳减排挑战。相对于传统气体分离技术,水合物法CO₂分离捕集技术具有环境友好、工艺简单、能耗低等特点,被认为是具有应用前景的CO₂分离捕集技术,因而被广泛研究。综合调研了国内外水合物法分离捕集CO₂的研究,从热力学、动力学、微观分析、分离工艺及分离装备、成本比较等方面对相关研究进行了系统分析及综合评价,并详细讨论了水合物平衡条件和不同类型添加剂对水合物平衡条件的影响。为进一步开发水合物法CO₂分离捕集技术的研究提供指导。     

水合物强化生成过程中传热传质机理研究进展

强化水合物生成技术在水合物领域一直是研究的热点,改善传热与传质过程是强化水合物生成时最关键的两个部分.其中改善传热能快速将反应生成的热量带走;强化传质一方面能加速气体溶解达到过饱和状态,另一方面能增大气体的消耗量,因此传热和传质两方面的机理都需要进一步深入研究.本文综述了大量专家学者在强化水合物生成时运用各种方式的研究...     

天然气水合物能源利用及天然气水合物汽车

简要介绍了天然气水合物的结构及性能，地层及天然气水合物能源利用的广阔前景和存在的问题，分析和综述了水合物储存天然气的有关技术及天然气水合物汽车的研究现状。     

Latest progress in numerical simulations on multiphase flow and thermodynamics in production of natural gas from gas hydrate reservoir

Natural gas hydrates are promising potential alternative energy resources. Some studies on the multiphase flow and thermodynamics have been conducted to investigate the feasibility of gas production from hydrate dissociation. The methods for natural gas production are analyzed and several models describing the dissociation process are listed and compared. Two prevailing models, one for depressurization and the other for thermal stimulation, are discussed in detail. A comprehensive numerical method considering the multiphase flow and thermodynamics of gas production from various hydratebearing reservoirs is required to better understand the dissociation process of natural gas hydrate, which would be of great benefit to its future exploration and exploitation.     

Effect of surfactants and liquid hydrocarbons on gas hydrate formation rate and storage capacity

Hydrate formation rate plays an important role in making hydrates for the storage and transport of natural gas. Micellar surfactant solutions were found to increase gas hydrate formation rate and storage capacity. With the presence of surfactant, hydrate could form quickly in a quiescent system and the energy costs of hydrate formation reduced. Surfactants (an anionic surfactant, a non‐ionic surfactant and their mixtures) and liquid hydrocarbons (cyclopentane and methylcyclohexane) were used to improve hydrate formation. The experiments of hydrate formation were carried out in the pressure range 3.69–6.82 MPa and the temperature range 274.05–277.55 K. The experimental pressures were kept constant during hydrate formation in each experimental run. The effect of anionic surfactant (sodium dodecyl sulphate (SDS)) on natural gas storage in hydrates is more pronounced compared to a non‐ionic surfactant (dodecyl polysaccharide glycoside (DPG)). The induction time of hydrate formation was reduced with the presence of cyclopentane (CP). Cyclopentane and methylcyclohexane (MCH) could increase hydrate formation rate, but reduced hydrate storage capacity The higher methylcyclohexane concentration, the lower the hydrate storage capacity. Copyright © 2003 John Wiley & Sons, Ltd.     

储气用天然气水合物强化制备的研究进展

天然气是一种清洁、高效的能源,未来的需求量呈增长趋势。以水合物方式储运天然气与传统的储运天然气方式相比,具有经济、安全等优势。采用水合物进行天然气的固态运输具有良好的开发前景。介绍了天然气水合物强化制备的几种方式,有搅拌法、喷雾法、喷射法、鼓泡法,还有加入添加剂以及外场等方式,通过阐述各种方式的工作原理说明这些强化方式可以加快反应速率和增加天然气水合物的储气密度。     

Development of a hybrid compressed gas engine/PEFC power system using the dissociation expansion characteristics of gas hydrate

The pressure of dissociation and expansion of a gas hydrate can fully power a compression gas engine with a temperature change from 0 °C to 10 °C. The use of green energy (high temperature) and simple refrigeration (low temperature) can easily provide this temperature difference. The dissociation characteristics of a hydrate can be used to develop a clean and efficient hydrate actuator (HA). In this paper, we examine the operation of a hybrid power system consisting of an HA engine and a proton-exchange membrane fuel cell (PEFC), using an example application of an individual house in Sapporo, Japan. A power-generation system that uses the exhaust heat of a PEFC and the cold energy of a heat pump to dissociate and recombine a hydrate is proposed. The results of this analysis indicate that the average electricity production efficiency on a representative day may reach 60.5%. This technique of using the dissociation expansion characteristics of a gas hydrate for power-generation deserves further attention in the search for clean energy.     

Experimental study on a small scale of gas hydrate cold storage apparatus

To have an overall investigation of cold storage characteristics to help to promote the application, a novel small scale of gas hydrate cold storage apparatus was designed. The amount of cold energy, growth rate, Hydrate Packed Factor (HPF) and overall heat transfer coefficient during the cold storage process were calculated and analyzed under different heat exchangers, sodium dodecyl benzene sulfonate (SDS) concentrations, hydration enhancement ways, inlet coolant temperatures and flow rates, etc. Results show that the cold storage performance could be improved greatly by adding a heat exchanger with vertical metal fins; SDS with concentration of 0.04 wt.% could help to improve the cold storage performance effectively. In addition, decreasing of the coolant temperature or increasing of the coolant flow rate could also make the amount of cold storage increased; it was found that mechanical blending for 5 min was the better hydration enhancement way than others, which presents the perspective for practical application.     

海底天然气水合物资源的研究及开发现状

海底天然气水合物是水分子和甲烷等气体组成的固态结晶，储量大、分布广的特点使其成为一种极具吸引力的潜在新能源。在关注这一潜力巨大的新能源的同时，它在地质、环境方面的重大意义和影响也是不容忽视的。文中从分子结构、物化性质、储存及开采等不同角度介绍了天然气水合物的形成和开发现状，并进一步阐述了天然气水合物开发的前景和所面临的问题。     

Experimental study of sand control in a natural gas hydrate reservoir in the South China sea

Gas hydrate is considered to be one of the most promising energy sources of the 21st century, however, with the deepening of research on hydrate resources and the acceleration of trial exploitation processes, it has become apparent that sand production is one of the key factors restricting hydrate exploitation. Here we focus on the key issues of sand production in natural gas hydrate reservoirs in the Liwan Sea area in the northern part of the South China Sea. Innovative systematic studies of the mode of hydrate sand production using a multi-channel hydration acoustic wave monitoring system were conducted. The results show that a hydrate formation composed of very fine silt is prone to excessive sand production requirement. When the production pressure difference is only 1 MPa, the sand output already accounts for 19% of total liquid production, making sand production an important issue under these conditions. Finally, using filter screens with different pore sizes, hydrate reservoir sand control simulations were carried out. The results were analysed to determine properties such as: sand yield, permeability, sand content, and productivity. The design criterion for the filter screen of the fine sand particles in hydrate formations was finally obtained as D₅₀ = 11d₅₀ (where D₅₀ is median grain size of the gravel, and d₅₀ is the median grain size of the formation).     

海洋渗漏型天然气水合物气力提升特性模型分析

运用多相流体动力学理论，建立了气力提升开采海洋渗漏型天然气水舍物系统工艺参数的数学分析模型。结合实际水舍物藏开采条件，分析了气力提升系统主要工艺参数之间的关系及对提升动态特性的影响规律。在此基础上，对气力提升方法的能量效率进行了计算评估。计算结果表明，该种开采方法的能量效率远高于传统的注热开采方法。     

Hydrogen and chemical energy storage in gas hydrate at mild conditions

Hydrogen storage in clathrate hydrates is a promising approach for industry-scale utilizations. However, extreme operation conditions such as high pressure (about GPa) limit the development. In this work hydrogen hydrate phase equilibrium in addition of methane, tert-butyl alcohol (tBA), trichloromethane (CHCl₃) and 1,1-dichloro-1-fluoroethane (HCFC-141 b) are reported at 6 MPa–20 MPa and 274 K–286 K, which including 21 points in total. Mechanism studies using Raman spectroscopy show that tBA and H₂O form metastable hydrate cages via hydrogen bonds, then form stable sII hydrates with the help of CH₄. Hydrate-based hydrogen storage capacity in 5.6 mol%HCFC-141 b-water mixture could reach 46 V/V (0.36 wt%) at 273 K and 10 MPa. Combing with chemical energy of HCFC-141 b, this work achieved high capacity of hydrogen and chemical energy storage in gas hydrate at mild conditions. This study will provide guidance on hydrate-chemical hybrid hydrogen storage technology, and leads to the next generation of hybrid hydrate-based hydrogen technology in the future.