新型吸收剂捕集燃气电厂烟气中二氧化碳的中试研究

Pilot Study on a New Absorbent Captures Carbon Dioxide in Flue Gas of Gas-Fired Power Plant

化学吸收法碳捕集技术是当前最具大规模工业化应用前景的烟气二氧化碳捕集技术,但存在能耗高的问题,开发低能耗碳捕集吸收剂可有效降低捕集过程对发电效率下降造成影响。结合燃气电厂烟气二氧化碳分压低的特点,通过实验室吸收解析试验和理化性质测试筛选出一种具备工业应用潜力的吸收剂(DTC01)。该吸收剂的解析速率较30%乙醇胺水溶液(monoethanolamine,MEA)高出近1倍。为了验证其在工业应用的表现和经济性,在华北地区某天然气电厂二氧化碳捕集中试装置上开展长周期运行实验。实验结果表明,在该中试装置上DTC01吸收剂长期运行时二氧化碳捕集率不低于90%,再生能耗为3.59MJ/kg,比MEA最低能耗值降低近20%,电耗降低近9%。受中试装置吸收塔填料层高度的限制,DTC01在中试装置上运行无法达到理论二氧化碳负荷的最高值,导致其再生能耗比实验室测试结果高,可进一步通过工艺优化提高其在工业应用的表现和经济效益。

Chemical absorption carbon capture technology is the most promising flue gas carbon dioxide capture technology for large-scale industrial application,but it has the problem of high energy consumption.The development of low-energy carbon capture absorbers can effectively reduce the impact of the capture process on the reduction of power generation efficiency.In this paper,combined with the characteristics of low partial pressure of carbon dioxide in gas-fired power plants,an absorbent with industrial application potential was screened out by laboratory absorption-desorption test and physicochemical property test.The desorption rate of this absorbent is nearly twice that of 30%aqueous ethanolamine(MEA).In order to verify its performance and economy on the industrial system,a long-term operation experiment was carried out on the carbon dioxide capture centralized test unit of a natural gas power plant in North China.The experimental results show that the carbon dioxide capture rate of the long-term operation of DTC01 absorbent on the pilot plant is not less than 90%,and the regeneration energy consumption is 3.59MJ/kg,which is nearly 20%lower than the minimum energy consumption value of MEA and the power consumption is reduced by nearly 9%.Due to the height of the packing layer of the absorption tower of the pilot plant,DTC01 cannot achieve the theoretical maximum carbon dioxide load in the pilot platform,resulting in higher regeneration energy consumption than laboratory test results,which can further improve its performance and economic benefits on industrial systems through process optimization.