中国二氧化碳捕捉与封存(CCS)技术早期实施方案构建研究

A Study into Devising CCS Implementation Schemes for Early Stage of Deployment in China

一个完整的二氧化碳捕捉与封存(CCS)系统包含了捕捉、运输和封存三个环节,且每个环节又有多种技术选择,在CCS大规模推广的初期,如何根据本国国情,选择最合适的备选技术进行组合,构建最佳的实施方案,已成为CCS研究中一个亟待解决的问题。为此引入CCS链的概念,从排放源、捕捉技术、运输技术和封存技术4个方面分析比较CCS各备选技术的优势和不足。对于老电厂的CCS改造,超临界是最佳的实施对象;而对于新建电厂,IGCC是最佳的实施对象。燃烧后捕捉将是匹配煤粉(PC)电厂的捕捉技术,而燃烧前捕捉则应匹配新建IGCC电厂。管道运输将是我国早期实施CCS的运输方式。注二氧化碳驱油提高采收率(CO2-EOR)和深部盐水层封存将是我国早期实施CCS的首选封存技术。最终构建了4条CCS链作为我国早期的CCS实施方案,即超临界PC电厂+燃烧后捕捉+管道运输+EOR封存;超临界PC电厂+燃烧后捕捉+管道运输+深部盐水层封存;IGCC电厂+燃烧前捕捉+管道运输+EOR封存;IGCC电厂+燃烧前捕捉+管道运输+深部盐水层封存。

A complete carbon dioxide capture and storage(CCS) system consists of three components-caputure,transportation and sequestration,each of which can be achieved by means of multiple technical options.It is a challenge requiring immediate resolution in CCS research to find the best way of forming a portfolio with the most suitable technical options in accordance with the prevailing conditions of the country to produce the best implementation plan for the initial stage of massive deployment of CCS technology.To meet this objective,the article has introduced a concept of CCS chain and compares the advantages and disadvantages of various CCS options in four areas-emission source,caputure technique,transportation technique and sequestration technique.For the application of a CCS system for old power plants,supercritical generating sets are the best objects for applying CCS,while for new power plants,IGCC is the best object.Post-combustion capture is the most suitable carbon capturing technology for pulverized coal(PC)-fired power plants,while prior-combustion capture should be used for new IGCC power plants.Pipeline transport will be the main mode of transportation in the early stage of CCS deployment in China.Carbon dioxide oil flooding for enhanced oil recovery(CO2-EOR) and sequestration in deep salt water formations will be the primary carbon storage methods used by China in the early stage of CCS deployment.Four CCS chains are established in this article as China’s CCS schemes in the early stage of deployment,namely,supercritical PC power plant + post-combustion capture + pipeline transportation + EOR storage;supercritical PC power plant + post-combustion capture + pipeline transportation + deep salt water formation storage;IGCC power plant + prior-combustion capture + pipeline transportation + EOR storage;and IGCC power plant + prior-combustion capture + pipeline transportation + deep salt water formation storage.