机械扰动强化气体水合物快速生成研究进展

气体水合物技术在天然气固态储运、CO₂捕获与封存等领域具有广阔的应用前景。高效快速制备水合物是水合物应用技术产业化的关键技术之一。从成核机理、相平衡、传热和传质等角度简述了气体水合物快速生成机理,回顾了常见的搅拌、喷淋和鼓泡等机械扰动强化气体水合物快速生成方法的基本原理和特性。依据强化传质传热领域内的新进展,进一步阐述了新型机械扰动强化气体水合物快速生成方法的基本原理和特性,重点综述了流化床、超声波、超重力、撞击流等技术的研究进展。从耗气率、水合物生成速率、总能耗、气体转化率等角度分析评价了各种机械扰动强化气体水合物快速生成方法的优缺点。总体来说,目前各种机械扰动强化气体水合物生成技术仍处于实验室阶段,传统的搅拌、喷淋和鼓泡强化技术生成速率较低;新型的流化床、超声波、超重力和撞击流等技术也存在各种不同的缺点,有待进一步优化改进。同时指出探究微观成核机理、开发新型易固液分离的气体水合物生成系统以及构建水合物反应器评价体系等是未来气体水合物快速生成相关研究中需要进一步解决的问题。     

气体水合物生成过程强化方法研究现状

气体水合物因其特殊的物理化学特性,已被气体分离、二氧化碳捕集与封存、海水淡化、气体储运等诸多领域学者广泛研究。但气体水合物生成条件较为苛刻、生成速率及储气能力较商业化应用还有较大差距。本工作从气体水合物生成条件、生成速率、储气能力等角度,分别综述了机械强化、外场作用、添加剂等强化方法对气体水合物生成过程的强化原理、技术特征及其研究现状;综合比较分析了各种强化方法的优势及存在的问题;展望了各强化方法的未来发展方向及其适用领域;特别是针对气体水合物法海水淡化的技术特征和关键问题,提出以外电场强化气体水合物法海水淡化过程的新思路。     

气体水合物快速生成强化技术与方法研究进展

水合物技术可应用于天然气储运、污水处理、海水淡化、混合气体分离、水溶液浓缩以及水合物蓄冷等领域,而该技术成功应用的关键在于如何强化水合物快速生成.本文介绍了水合物的生成机理,综述了气体水合物快速生成强化技术与方法研究进展,分析了各自的优缺点,并对气体水合物快速生成技术进行了展望.     

水合物储运天然气的新进展与新构想

天然气作为一种清洁、高效的能源,近年来在缓解我国能源紧张方面扮演着重要角色。随着天然气在我国能源消费结构中所占比例的不断增加,必然需要发展经济的天然气储运方法。以天然气水合物方式储运天然气与传统的储运天然气方式相比,有着经济、安全等优势,是发展新型天然气储运技术的研究重点。本文概括了目前天然气主要的储运方式,并对其进行了经济性和优缺点的比较,重点介绍了水合物储运天然气的研究现状,最后提出了一种新型的采用压缩式制冷循环的天然气水合物制备系统,该系统具有结构简单、储运效率高等优点。     

天然气水合物储运技术综述

在能源危机日益严峻的21世纪,天然气水合物被公认为是具有良好前景的重要后续能源。其储运技术在近年来也得到了大力的发展。本文介绍了天然气水合物的特性、目前天然气主要的储运方式以及国内外水合物储运技术的应用前景。     

多孔材料中甲烷水合物生成的传热数值模拟研究

水合物储运(NGH)是近几年发展起来的天然气储运技术,已具备实现工业化的潜力。但水合物的生长是传质传热控制的反应,因此在放大实验中存在诸多不确定因素。针对该问题,对水合物反应器中多孔材料内甲烷水合物生成传热过程建立了基于化学反应动力学和多孔材料内传质传热的甲烷水合物生成传热数学模型,可用于计算反应器内水合物生成分布和热量分布,指导水合反应器的设计和优化。通过模拟与实验数据对比验证了该模型的可靠性,并对使用了不同热导率填料的水合反应过程进行数值模拟。结果显示,模拟值与实验值的绝对平均相对误差小于6%,生成传热模型准确性高;在水合反应过程中,热量传递是影响水合物生成速率的关键因素之一。导热不良时,易在水合物生成中心部分形成局部过热,对水合物生长造成热抑制。在进行水合物生成放大实验时,应特别注意反应器内部的热量控制。     

多孔材料中甲烷水合物生成的传热数值模拟研究

水合物储运(NGH)是近几年发展起来的天然气储运技术,已具备实现工业化的潜力。但水合物的生长是传质传热控制的反应,因此在放大实验中存在诸多不确定因素。针对该问题,对水合物反应器中多孔材料内甲烷水合物生成传热过程建立了基于化学反应动力学和多孔材料内传质传热的甲烷水合物生成传热数学模型,可用于计算反应器内水合物生成分布和热量分布,指导水合反应器的设计和优化。通过模拟与实验数据对比验证了该模型的可靠性,并对使用了不同热导率填料的水合反应过程进行数值模拟。结果显示,模拟值与实验值的绝对平均相对误差小于6%,生成传热模型准确性高;在水合反应过程中,热量传递是影响水合物生成速率的关键因素之一。导热不良时,易在水合物生成中心部分形成局部过热,对水合物生长造成热抑制。在进行水合物生成放大实验时,应特别注意反应器内部的热量控制。     

天然气水合物储运技术

天然气水合物(NGH)的研究是当今世界能源开发的热点。本文了介绍了天然气水合物储运方法的研究背景,总结了然气水合物储运方法的特点。分析总结了天然气水合物储运方法,关键技术及待解决的技术难点,并对天然气水合物储运技术的展望。     

分析水合物储运天然气技术的研究进展

我国有着极为丰富的天然气水合物储藏资源。在针对这部分天然气资源进行开发与利用的过程当中,如何实现安全且有效的储运是现阶段相关人员普遍关注的问题之一。本文以水合物储运天然气技术为研究对象,从天然气水合物的储存技术分析以及天然气水合物的运输技术分析这两个方面入手,围绕水合物储运天然气技术的研究进展这一中心问题展开了较为详细的分析与阐述,并据此论证了水合物储运天然气技术所表现出的安全性、经济性以及高效性优势。以上问题希望能够引起各方工作人员的特别关注与重视。     

撞击流反应器内快速生成甲烷水合物

为了快速制备甲烷水合物以利于天然气水合物法储运,在自行搭建的液相连续撞击流反应器内考察了纯水和纯水+十二烷基硫酸钠(SDS)2种体系中撞击强度、反应器内温度、初始压力对甲烷水合物快速生成的影响.实验结果表明:2种体系内撞击强度的增加可明显加快甲烷水合物的生成,在撞击强度为0.38、反应的前30 min,水合速率达到最大...     

Effect of additives on formation of natural gas hydrate

The formation of natural gas hydrate (NGH) is studied in this work. Kinetics data of hydrate formation with no agitation were collected at various concentrations of the aqueous solutions with different additives such as alkylpolyglucside, sodium dodecyl benzene sulfonate and potassium oxalate monohydrate. Various kinds of additive increased the formation rates of NGH and its storage capacity and reduced the induction time of NGH formation. Moreover, the storage capacity, the induction time and the hydrate formation rate were influenced by the concentration of the aqueous solution.     

Modelling of hydrate formation kinetics: State-of-the-art and future directions

Clathrate hydrates have drawn considerable attention in the last few years due to a variety of possible applications, including transportation and storage of natural gas and carbon dioxide sequestration in the ocean. These applications require the development of effective hydrate formation reactors, which, in turn, asks for a comprehensive understanding of hydrate formation kinetics. Contrary to hydrate thermodynamics, hydrate kinetics are still poorly understood. In the present contribution, a critical review of the literature on hydrate kinetics is provided, with special emphasis upon modelling efforts, essential to the design of any reactor. The main features of the models available in the literature for hydrate nucleation and growth are discussed, together with their limitations. In addition, suggestions for further developments are presented.     

Evaluation on the natural gas hydrate formation process

Gas hydrates have endowed with great potential in gas storage, and rapid formation of gas hydrates is critical to use this novel technology. This work evaluated the natural gas hydrate formation process, which was compared from six parameters, including conversion of water to hydrate, storage capacity, the rate of hydrate formation, space velocity (SV) of hydrate reaction, energy consumption and hydrate removal. The literature was selected by analyzing and comparing these six parameters mentioned above, meanwhile placing emphasis on the three parameters of storage capacity, the rate of hydrate formation and space velocity of hydrate reaction. Through analysis and comparison, four conclusions could be obtained as follows. Firstly, the overall performance of the stirring process and the spraying process were better than other processes after analyzing the six parameters. Secondly, the additive types, the reactor structure and the reactor size had influence on the natural gas hydrate formation process. Thirdly, the energy consumption via reciprocating impact in the hydrate formation process was higher than that via stirring, spraying and static higee. Finally, it was one key for hydrate removal to realize the hydrate industrial production.     

车载天然气水合物储运装置

天然气水合物(NGH)储运技术是一种安全高效且费用较低的储运方法。储运水合物车载装置的出现,为天然气运输又增添了一种选择方式。根据水合物特点,分析了车载装置储运天然气水合物的可行性,介绍了装置的基本结构。NGH储运技术作为一种新式的天然气传输方式,在未来的社会中一定大有可为。     

不同饱和度的天然气水合物降压分解实验

天然气水合物作为一种新能源已得到世界各国的关注,降压是水合物藏的一种有效开采方式。采用自制的天然气水合物开采模拟实验装置,在多孔介质中生成不同饱和度的天然气水合物,之后进行缓慢降压开采实验。结果表明：降压开采可分为自由气产出、水合物降压分解产气和最后降压产出已分解气三个阶段。在降压分解阶段,当水合物饱和度从16%增加到48%时,平均产气速率先增加后减小,说明水合物饱和度对降压分解产气速率的影响是非线性的。降压分解时,水合物饱和度越大,温度下降幅度越大。实验研究范围内,中等饱和度（32%）的水合物藏降压分解产气速率比较大,降压开采效果较好。     

Investigation on the effect of oxalic acid,succinic acid and aspartic acid on the gas hydrate formation kinetics

Gas hydrate reserves are potential source of clean energy having low molecular weight hydrocarbons trapped in water cages. In this work, we report how organic compounds of different chain lengths and hydrophilicities when used in small concentration may modify hydrate growth and either act as hydrate inhibitors or promoters. Hydrate promoters foster the hydrate growth kinetics and are used in novel applications such as methane storage as solidified natural gas, desalination of sea water and gas separation. On the other hand, gas hydrate inhibitors are used in oil and gas pipelines to alter the rate at which gas hydrate nucleates and grows. Inhibitors such as methanol and ethanol which form strong hydrogen bond with water have been traditionally used as hydrate inhibitors. However, due to relatively high volatility a significant portion of these inhibitors ends up in gas stream and brings further complexity to the safe transportation of natural gas. In this study, organic additives such as oxalic acid, succinic acid and L-aspartic acid (all three) having—COOH group(s) with aspartic acid having an additional—NH₂ group, are investigated for gas hydrate promotion/inhibition behavior. These compounds are polar in nature and thus have significant solubility in liquid water; the presence of weak acidic and water loving (carboxylic/amine groups) moieties makes these organic acids an excellent candidate for further study. This study would pave ways to identify a novel(read better) promoter/inhibitor for gas hydrate formation. Suitable thermodynamic conditions were generated in a stirred tank reactor coupled with cooling system; comparison of gas hydrate formation kinetics with and without additives were carried out to identify the effect of these acids on the formation and growth of hydrates. The possible mechanisms by which these additives inhibit or promote the hydrate growth are also discussed.