膜法脱除天然气中二氧化碳的工艺技术发展现状

Technology development status of carbon dioxide removal from natural gas by membrane process

综述了目前膜法脱除天然气中二氧化碳的工艺技术发展现状。首先对比了天然气脱除二氧化碳多种工艺技术特点及应用场合情况,膜分离法相比于其他分离方法,具有投资较少、占地小、耗能少等优势。介绍了膜法分离原理、膜材料、膜组件发展现状和膜法脱除天然气中二氧化碳工艺技术单元情况。而工艺技术单元又分为预处理单元和膜分离单元:预处理单元根据采出原料气成分选择不同脱除方法进行组合;原料气经预处理单元后进入膜分离单元,根据实际工况,综合考虑烃类回收率、占地、能耗、投资等因素合理地设计膜法脱碳分离工艺。然后又对国内外膜法脱除天然气中二氧化碳应用案例进行介绍,目前国外膜法脱除天然气中二氧化碳应用案例较多,而国内应用案例较少,因此需加大国内膜法脱除天然气中二氧化碳的工业应用。最后对天然气膜法脱除二氧化碳技术发展方向进行了展望,指出研发具有自主知识产权并且在实际复杂工况条件下能保持高性能、长周期稳定性的膜材料是未来膜分离技术发展的重点,同时将两种或两种以上的单一脱除二氧化碳技术相结合的耦合集成组合工艺,如膜法分离+化学吸收法、膜法分离+变温吸附法等,这种耦合集成组合工艺为未来脱碳工艺技术发展提供了新方向。

The current development status of membrane technology for CO_(2) removal from natural gas was reviewed.Firstly,the technical characteristics and application situations of various processes for removing CO_(2) from natural gas were compared.Compared with other separation methods,the membrane separation method has the advantages of less investment,small footprint,and low energy consumption.The principle of membrane separation,membrane materials,development status of membrane modules,and technical units of membrane technology to remove CO_(2) from natural gas were introduced.The process technology unit was further divided into pretreatment unit and membrane separation unit:the pretreatment unit was selected to different removal methods to combine according to the components of the produced raw material gas;the raw material gas was entered the membrane separation unit after passing through the pretreatment unit.According to the actual working conditions,considering the hydrocarbon recovery rate,land occupation,energy consumption,investment and other factors,the membrane decarbonization separation process was reasonably designed.Then,the domestic and foreign application cases for the removal of CO_(2) from natural gas by membrane methods were introduced.At present,there were many application cases of foreign membrane methods to remove CO_(2) from natural gas,while there were few domestic application cases.Therefore,it was necessary to increase the domestic membrane method to remove CO_(2) from natural gas industrial applications.Finally,the development direction of CO_(2) removal technology by natural gas membrane method was prospected.The research and development of membrane materials with independent intellectual property rights and maintaining high performance and long‐term stability under actual complex working conditions is the focus of future membrane separation technology development.A coupled integrated combined process was that combining two or more single CO_(2) removal technologies,such as membrane separation+chemical absorption,membrane separation+temperature swing adsorption,etc.This coupled integrated combined process would provide new directions for the future decarbonization process technological developments.