基于富氧燃烧的CO_(2)压缩纯化技术研究进展

Research progress of CO_(2) compression and purification technology based on oxy-fuel combustion

作为一种燃烧中的碳捕集技术,富氧燃烧可实现烟气中CO_(2)高浓度富集,在进行CO_(2)的封存和利用前,需在CO_(2)压缩纯化系统中对富含CO_(2)的烟气进行净化、干燥和液化,便于运输和降低成本。现有研究表明,CO_(2)压缩纯化系统在高压低温的条件下可以分别实现SO_(2),NO_(x)及Hg的一体化脱除,干燥脱水,分离O,N等杂质气体,从而液化提纯CO_(2)气体。基于富氧燃烧碳捕集技术,分别介绍了CO_(2)压缩纯化系统中酸压缩污染物协同脱除技术,对酸压缩过程协同脱除SO_(2),NO_(x)及Hg的反应机理以及相互作用机制进行了探讨;简述了二氧化碳脱水干燥的几种方法,对分子筛脱水技术进行了探究;对比分析了高浓度CO_(2)液化提纯技术的主要方法以及CO_(2)液化提纯系统所需的低温冷能获取方式。综述了国内外富氧烟气CO_(2)压缩纯化技术的中试示范应用,并指出未来发展方向。我国酸压缩污染物协同脱除技术的示范应用滞后于CO_(2)液化提纯技术,需明确酸压缩污染物协同脱除的具体机制及运行参数的影响,在国内开展同步实现SO_(2),NO_(x)和Hg联合脱除的示范应用研究。目前的中试示范项目对于CO_(2)压缩纯化系统各单元设备运行特性研究不够深入,需进一步开发工艺并完善系统集成方案,进行百万吨级CO_(2)压缩纯化系统方案集成研究,促进CO_(2)压缩纯化技术大规模工业应用。

As a carbon capture technology in combustion process, oxy-fuel combustion can achieve a high concentration of CO_(2)in flue gas. Before sequestering and utilizing CO_(2), the CO_(2)-rich flue gas needs to be purified, dried and liquefied in a CO_(2)compression and purification system for ease of transportation and cost reduction. Current studies showed that the CO_(2)compression and purification system could achieve the combined removal of SO_(2), NO_(x)and Hg, dry dehydration, separation of O, Nand other inert gases, and thus liquefy and purify CO_(2)gas under high pressure and low temperature. Based on the oxy-fuel combustion carbon capture technology, the combined removal of pollutants by sour compression in CO_(2)compression and purification system was introduced, and the reaction mechanism and interaction mechanism of synergistic removal of SO_(2), NO_(x)and Hg in the sour compression process were discussed. Several methods of dehydration and drying of carbon dioxide were briefly recommended, and a molecular sieve dehydration technology was explored. The main methods of high concentration CO_(2)liquefaction purification technology and the way of obtaining low temperature cold energy required by the CO_(2)liquefaction purification system were compared and analyzed. The pilot scale and demonstration application of CO_(2)compression purification technology for oxy-fuel flue gas at home and abroad were reviewed and the future development direction was pointed out. The demonstration and application of the combined removal technology of acid compression pollutants lags behind the CO_(2)liquefaction and purification technology in China. It is indispensable to clarify the specific mechanism of combined removal of acid compression pollutants and the impact of operating parameters, and carry out the demonstration and application study of simultaneous removal of SO_(2), NO_(x)and Hg in China. The current pilot scale demonstration project is not sufficient enough to study the operation characteristics of each unit of the CO_(2)compression and purification system. Therefore, it is necessary to further develop the process and improve the system integration scheme, conduct the integration study of the one-million-ton CO_(2)compression and purification system scheme, and promote the large-scale industrial application of CO_(2)compression and purification technology.