不同压力下冻土区水合物法封存CO_(2)的实验研究  

Experimental study of CO_(2) storage using hydrate method under various pressures in permafrost region

作　　者：高强 赵建忠[2] 侯斌[2] 张驰 GAO Qiang;ZHAO Jianzhong;HOU Bin;ZHANG Chi(College of safety and Emergency Management Engineering,Taiyuan University of Science and Technology,Taiyuan,Shanxi,China;Key Laboratory of In-situ Property-improving Mining of Ministry of Education,Taiyuan University of Technology,Taiyuan,Shanxi,China)

机构地区：[1]太原科技大学安全与应急管理工程学院 [2]太原理工大学原位改性采矿教育部重点实验室

出　　处：《石油与天然气化工》2024年第3期49-55,63,共8页Chemical engineering of oil & gas

基　　金：太原科技大学科研启动基金(20232107);博士后面上71批基金(2022M712337);山西省科技创新人才团队专项资助(202304051001012)。

摘　　要：目的水合物法封存CO_(2)稳定性良好、储气密度高,是一种极具潜力的碳封存方式,利用冻土区的地层条件更具独特优势,将CO_(2)气体注入冻土区地层中,在一定的温度和压力条件下,形成固态CO_(2)水合物实现封存。方法依据国内冻土地区地层深度对应的温度和压力条件,选取不同地层深度(150 m和200 m)对应温度(1.27℃和2.72℃)和有效孔隙含水率(40%),研究不同注气压力(3.5 MPa、4.5 MPa和5.5 MPa)下的封存特征。分析封存过程的温度和压力变化、封存速率、最终水转化率和最终封存率等动力学规律。结果封存压力越高,水合物法封存所需的诱导时间越短,压力降幅越大。较高的封存压力导致初期封存速率较慢,缓慢封存期的持续时间减少,且封存压力越高,封存率、最终水转化率和水合物相饱和度越高。封存温度越高,压力对封存率的影响效果越明显。结论在地层深度150 m(对应地层平均温度1.27℃)、5.5 MPa及有效孔隙含水率(40%)的条件下,CO_(2)封存效果最佳。Objective CO_(2) storage via the hydrate method is one of the potential carbon storage methods because of its stability and high gas storage capacity.The use of formation conditions in permafrost region has more unique advantages.CO_(2) is injected into the permafrost region,and solid-state CO_(2) hydrate is formed under specific temperature and pressure conditions to achieve long-term stable storage.Methods According to the temperature and pressure conditions of the formation in the permafrost region of China,the temperature(1.27℃ and 2.72℃)and effective pore water content(40%)corresponding to different formation depths(150 m and 200 m)and different initial injection pressures(3.5 MPa,4.5 MPa and 5.5 MPa)were selected.The characteristics of kinetic parameters such as temperature and pressure changes,storage rate,final water conversion rate and final storage ratio in the CO_(2) storage process via the hydrate method were analyzed.Results The results of the CO_(2) hydrate storage process under different initial injection pressures show that the higher the initial injection pressure,the shorter the induction time required for hydrate storage and the larger the pressure drop.Higher injection pressure results in a slower storage rate at the initial stage and a reduced duration of the slow storage period.The higher the injection pressure,the higher the hydrate storage ratio,the final water conversion rate,and the hydrate phase saturation at the end of the reaction.The higher the storage temperature,the more obvious the effect of pressure on the gas storage ratio.Conclusions The best CO_(2) storage effect was achieved under 40% water content at the depth of 150 m(the average temperature of the formation is 1.27℃)and 5.5 MPa.

关 键 词：冻土区 水合物 CO_(2) 封存 注气压力 

分 类 号：TQ116.3[化学工程—无机化工] X701[环境科学与工程—环境工程]