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含极性抑制剂体系中水合物生成条件的研究 总被引:3,自引:0,他引:3
应用两步水合物热力学模型,结合基于局部组成概念的混合规则,将水合物生成条件预测成功地扩展应用于含极性抑制剂体系,计算结果较理想,大量检验结果表明,单流体混合规则不能很好地描述极性体系。同时可以看出,极性体系相对平衡计算的准确性对水合物生成条件预测有很大的影响。 相似文献
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工业中常见的含氢气体往往含有较多的轻烃,而不同轻烃组成的变化能够引起水合物结构类型的转变,这也是影响水合物热力学模型预测精度的重要原因之一。因此,本文首先针对轻烃混合气体,在Chen-Guo水合物模型中引入新的水合物结构参数( )并通过实验数据拟合得到其参数值,以判断和计算因气体组成变化而引起的sⅠ/sⅡ型水合物转变的热力学相平衡。在此基础上,将含氢气体中的氢气视为只能被水合物小孔(联结孔)吸附的惰性气体,提出一种考虑水合物结构转变的相平衡模型,以提高含氢气体的水合物相平衡预测精度。结果表明,该模型对不同轻烃气体的水合物相平衡条件预测平均相对误差由约5.6%降至2.1%,对不同含氢气体的水合物相平衡条件预测平均相对误差由约8%降至2.3%,模型预测精度明显提高,能够满足工程应用要求。 相似文献
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引 言由于水合物不仅与石油天然气生产、储藏和运输密切相关 ,而且与环境保护、气候变迁特别是人类未来赖以生存的能源有密切关系 ,对于水合物的研究成为目前国际上的一个热点 .另外 ,由于其特殊的物理化学性质 ,水合物还可以用来开发各种应用技术 ,例如蓄冷、有机水溶液提浓、海水脱盐淡化、重水提浓等[1] .水合物法分离气体混合物技术是在多年水合物相关实验研究[2 ,3] 的基础上提出的一种新技术 ,并在氢气分离提浓方面取得了初步成果 .水合物是小分子物质 (N2 、CO2 、CH4 、C2 H6、C3H8等 ,称为客体分子 )和水在一定温度和压… 相似文献
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气体水合物平衡生成条件的测定及预测 总被引:14,自引:0,他引:14
建立了一套气体水合物实验测定装置,采用该装置在温度262.6-285.2K范围内分别测定了甲烷,二氧化碳和一种合成天然气在纯水、电解质水溶液以甲醇水溶液中水合物的平衡生成压力,共计9个体系,78个数据点。 相似文献
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甲烷+氨水体系水合物生成条件实验测定及计算 总被引:1,自引:0,他引:1
甲烷在氨水体系中生成水合物的实验数据对于开发水合法回收合成氨驰放气工艺以及操作条件的确定具有重要意义。本文测定了氨摩尔分数为1.018、3.171、5.278氨水溶液中甲烷气体水合物的生成条件。结果表明:氨的加入对甲烷水合物的生成起着明显抑制作用,而且随着氨浓度的增加,生成压力越高。采用Chen-Guo模型对甲烷在氨水中生成水合物的数据进行了计算,得到了较为满意的计算结果,平均误差为2.71%,说明Chen-Guo模型能够较好地预测该类体系的水合物的生成条件。 相似文献
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传统的统计热力学模型假设天然气水合物为理想固体溶液,同时忽略了极性水分子之间的氢键缔合作用,在预测高压条件下的水合物生成条件时偏差较大。针对这一问题,提出了基于CSM模型与CPA状态方程计算高压天然气水合物生成条件的新方法。基于该方法计算的5种高压天然气水合物生成条件与实验数据的对比表明:当水合物生成压力低于20 MPa时,水合物生成压力计算值与实验值之间的平均相对偏差范围为0.59%—5.24%;当压力范围为20—69.84 MPa时,计算值的平均相对偏差范围为0.79%—6.76%,显著优于CSM模型结合SRK状态方程的计算结果。预测高压条件天然气水合物生成条件时,需要同时考虑水合物溶液的非理想性和水分子之间氢键缔合作用。 相似文献
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1 INTRODUCTION Gas hydrates are serious problems in the petroleum and petrochemical industries since it may cause the plugging of production facilities and trans- portation pipelines during gas and oil production. It is known to all that gas hydrates have three poten- tial hydrate formation structures: structure- structure- and structure-H (SH). The two for- mer structures have been studied extensively and their phase equilibrium conditions are well characterized. For a long time, molecu… 相似文献
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气体水合物作为清洁能源,具有良好的利用前景,而且由于气体水合物资源量大,能量密度高,可作为理想传统化石燃料的替代品,因此受到各国相关领域专家和政府的高度关注。基于此,主要探讨几种典型气体水合物的分解行为,包括甲烷水合物,二氧化碳水合物,氢气水合物,并总结分析不同种类气体水合物的分解原理及实现过程,以期实现天然气水合物的大规模安全开采。 相似文献
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EQQUATION OF STATE BASED HYDRATE MODEL FOR NATURAL GAS SYSTEMS CONTAINING BRINE AND POLAR INHIBITOR 下载免费PDF全文
A new thermodynamic model for gas hydrates was established by combining the modified Patel-Teja equation of state proposed for aqueous electrolyte systems and the simplified Holder -John multi -shell hydrate model. The new hydrate model is capable of predicting the hydrate formation/dissociation conditions of natural gas systems containing pure water/formation water (brine) and polar inhibitor without using activity coefficient model. Extensive test results indicate very encouraging results. 相似文献
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EQUATION OF STATE BASED HYDRATE MODEL FOR NATURAL GAS SYSTEMS CONTAINING BRINE AND POLAR INHIBITOR 下载免费PDF全文
1 INTRODUCTIONIn the past two decades,as large reserves of hydrocarbons were discovered in the formof natural gas hydrates stored in deep oceans and permafrost regions such reserves mayturn out to become a tremendous energy source in the future.Among the challengingproblems emerged from offshore oil/gas exploration and production,hydrate research re-ceived new impetus. 相似文献
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由于氢键的作用,氟化氢分子会形成多聚体,造成其热力学性质大大的偏离理想气体的性质.作者提出一个适合于含有强缔合物质氟化氢体系的热力学模型.此模型即考虑了由于氢键作用而形成多聚物的化学平衡,同时又考虑到了单体及多聚体之间的物理作用.改进了SRK方程,用以描述含氟化氢体系的相态行为. 相似文献
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A recent study by Eggeman and Chaffin (2005), which showed large discrepancies in CO2 freeze-out conditions as predicted by several commercial simulators, prompted a reexamination of using the TBS equation of state for phase equilibrium calculations involving solids. Salim and Trebble (1994) had previously presented a methodology for extending the Trebble-Bishnoi-Salim (TBS) equation of state (Salim, 1990) to calculations involving a solid phase. In this study, the CO2 freeze-out conditions in CO2/CH4 and CO2/C2H6 mixtures are calculated from the TBS equation of state, and it is shown that they provide a better data fit than the traditional Poynting correction method. Furthermore, since the use of an equation of state in SLE/SVE calculations does not require the explicit assumption of a pure solid phase, the model was assessed for its ability to correlate CO2 gas hydrate equilibrium conditions. Gas hydrates were simply treated as an impure solid phase, and it was seen that the predictions of gas hydrate equilibrium were in very good agreement with the experimental data. Computationally, the use of the TBS equation of state has the advantage, over the model of Yokozeki (2005), that it does not require a modifying factor (cb) in the repulsive term to handle the presence of hydrates; they are instead handled using a unique binary interaction parameter for the hydrate phase. 相似文献
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INFLUENCE OF CHEMICAL ADDITIVES ON GAS HYDRATE FORMATION 总被引:2,自引:0,他引:2
TANG Cuiping FAN Shuanshi 《化工学报》2003,54(Z1):37-40
One surfactant as sodium dodecyl sulfate (SDS) and one synthesized sample as gas hydrate inhibitor are introduced in this paper. Through experiments we prove sodium dodecyl sulfate can accelerate the formation rate of gas hydrate and the synthesized sample can inhibit the formation and growth. 相似文献
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提出了在参考压力下将过量自由焓(g~E)模型引入状态方程的修正Huron-Vidal混合规则,由g~E模型确定状态方程中混合物的参数,以SRK方程和Wilson模型为例,取大气压为参考压力,计算了16个体系50组汽液平衡,结果表明本文建议的混合规则可直接使用现有文献报道的常压g~E模型参数由立方型状态方程预测常压汽液平衡,并对直接外推预测高压汽液平衡作了尝试. 相似文献
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This article compares the effects of using various types of equations of state (Peng-Robinson, PR; Soave-Redlich-Kwong, SRK; Esmaeilzadeh-Roshanfekr, ER; Patel-Teja, PT; and Valderrama-Patel-Teja, VPT) on the calculated driving force and rate of gas consumption based on the Kashchiev model in simple and double-gas hydrate formation for methane, ethane, and their mixtures with 1130 experimental published data points with or without the presence of kinetic inhibitors at various pressures and temperatures. For the prediction of gas consumption rate in double-gas hydrate formation, the rate equation based on the Kashchiev model for simple gas hydrate formation was developed using the calculation of gas mole fraction in hydrate phase and then prediction of gas hydrate formation rate for each component in gaseous mixture. The total average absolute deviation was found to be 8.72%, 10.34%, 8.84%, 11.04%, and 14.16% for the PR, ER, SRK, VPT, and PT equations of state for calculating gas consumption in simple and double hydrate formation, respectively. 相似文献