中国西北地区超基性岩封存CO_(2)潜力研究

Assessment of Carbon Dioxide Sequestration Potential of Ultramafic Rocks in Northwest China

超基性岩可通过碳酸盐化生成稳定的碳酸盐矿物,它是一种以地球化学手段有效且永久封存CO_(2)的矿物。在自然界中矿物封存CO_(2)可通过风化作用自发发生,人工干预能进一步提升碳酸盐化反应效率,促进工业化进程。笔者基于最新1∶100万西北地质图及数据库,试图对西北地区分布的超基性岩的封存潜力进行理论评估。结果表明,西北地区超基性岩封存CO_(2)量可达963.23亿t,其中新疆超基性岩CO_(2)封存量最大,可达613.52亿t,占西北地区总封存量的63.69%。西北地区超基性岩封存CO_(2)量大致相当于全国2021年CO_(2)排放量的10倍,在完全释放其固碳潜力的情况下,初步静态估算可封存全国CO_(2)排放量约10年。因此,西北地区超基性岩封存CO_(2)潜力巨大。未来,应针对单个超基性岩体收集已有大比例尺精细基础地质调查数据,并补充性开展调查及研究工作,进一步圈定CO_(2)地质封存的有利靶区,促进超基性岩封存CO_(2)的地质解决方案成为未来碳中和目标在西北地区落地实现的最优方案之一。

Carbonatization of ultramafic rocks is potentially important pathway for carbon mineralization occurred in nature,which is an effective and permanent geochemical trapping system for storing the CO_(2).The above process can be carried out spontaneously through weathering,and at the same time,manual intervention can further improve the efficiency of carbonatization reaction and promote the process of industrialization.Based on the 1∶1000000 geological map and database of northwest China,the storage potential of ultrabasic rocks is evaluated theoretically in this paper.After the statistics and calculations on the data of the ultramafic rocks of the northwest China,the results show that the CO_(2) sequestration capacity of ultramafic rocks.Totally 96.323 billion tons of carbon sequestration was estimated for northwest China,and the ultramafic rocks in Xinjiang have the greatest amount of CO_(2) sequestration,which can reach 61.352 billion tons,accounting for 63.69%of the total storage capacity in northwest China.The amount of CO_(2) sequestered by ultramafic rocks in north-west China is roughly 10 times as against the total CO_(2) countrywide emissions in 2021.Under the condition that the carbon sequestration potential is fully released,based on the national emissions in 2021,a preliminary static estimate suggest that CO_(2) can be sequestered for about 10 years.Therefore,ultramafic rocks in northwest China have great potential for CO_(2) sequestration.In the future,the fine basic geological survey data of the single typical ultramafic rock should be collected,and supplementary survey and research should be carried out to further delineate favorable targets for CO_(2) sequestration.In this region,the geological solution to promote the sequestra-tion of CO_(2) in ultramafic rocks has become one of best solutions to achieve the carbon neutrality goals in the future.