Ar提高CO2置换CH4水合物置换率研究

Promotion of Replacement Rate of CH Hydrates with CO by Adding Small Ar Gas

为验证Ar促进CO2置换CH4水合物实验方案的可行性,在自行设计的实验台上开展了可行性实验。通过设置不同的Ar/CO2的混合比例对照实验,研究在相同置换温度、压力条件下,充入不同Ar含量对置换过程中不同时刻CH4置换量、Ar和CO2的残余量及置换率的影响规律。置换实验的压力为3.5 MPa,温度为278.15 K,置换气体分别为纯CO2、Ar和CO2的混合气(混合比为1∶3、1∶4、1∶9)。实验研究表明:纯CO2置换CH4的置换率仅为4.6%,混合比为1∶3、1∶4、1∶9的混合气置换率分别为21%、63%和66%,所以Ar作为小分子气体添加剂促进了CO2置换CH4水合物,提高了CH4的置换率;随着充入Ar比率的增大,不同时刻CH4的置换量及置换率均有所提高,Ar和CO2的残余量有所减少;在置换反应的初始阶段CH4的置换率增长较快,在置换反应中后期,CH4的置换率变化平缓。

In order to verify the feasibility of adding Ar to promote the replacement rate of CH4 hydrate with CO2,a feasibility experiment was carried out on a self-designed test bench.With different mixing ratios of Ar/CO2,the influence of different Ar content on the replacement rate,CH4 replacement,residual amount of Ar and CO2 at different times during the replacement process was studied under the same replacement temperature and pressure.The displacement test pressure is 3.5 MPa and the temperature is 278.15 K.The replacement gas was pure CO2,and the mixtures of CO2 and Ar(mixing ratio is 1∶3,1∶4,1∶9).Experimental research showed:the replacement rate of pure CO2 for CH4 was only 4.6%,while those for The CO2-Ar mixing ratios of 1∶3,1∶4 and 1∶9 were 21%,63%and 66%,respectively.Ar as a small molecular gas additive promoted CO2 replacement of CH4 hydrate and improved the replacement rate of CH4.With the increase of Ar content,the replacement rate of CH4 was increased,Ar and CO2 residues were decreased at different time.In the initial stage of the replacement reaction,the replacement rate of CH4 was increased rapidly.In the middle and late stages of the replacement reaction,the change of the replacement rate of CH4 was slow.