摘要
钙法是利用Ca(OH)_(2)夺取富液中CO_(2)来解吸富液,并以CaCO_(3)形式固定CO_(2)的一种低能耗、低成本的化学再生方法。用Box-Behnken Design(BBD)响应面法对钙法解吸MDEA/PG富液过程进行优化,设定CO_(2)负荷、Ca(OH)_(2)投加量、反应时间和搅拌速率4个影响因子,CO_(2)解吸率为响应值,分析优化得出该方法的最佳解吸条件,并按此条件进行了多重再生–矿化循环动态试验,结合XRD和TEM图对碳酸化反应进行了探讨。结果表明,CO_(2)负荷、Ca(OH)_(2)投加量和搅拌速率对CO_(2)解吸率有显著影响。富液再生的最佳工艺条件是CO_(2)负荷0.8 mol/L、Ca(OH)_(2)投加量1:1、反应时间20 min、搅拌速率800 r/min,此条件下解吸率为83.68%。钙法解吸后MDEA/PG再生液具有良好的可重复使用性。Ca(OH)_(2)可有效矿化封存CO_(2)并能再生MDEA/PG。
Post-combustion CO_(2)capture(PCC)facilities are set up at the power plants to reduce substantial carbon dioxide emissions.However,the significant energy penalty and high capital cost remain the most critical challenge hindering the large-scale application of amine-based PCC technologies.Also,CO_(2)enriched by amine-based scrubbing requires storage processes.To overcome the shortage of CO_(2)desorption process,a chemical regeneration process was developed in which uses Ca(OH)_(2)to capture CO_(2)from rich solution and fix CO_(2)in the form of CaCO_(3).The BoxBehnken Design methodology was used to optimize desorption conditions,including CO_(2)loading,Ca(OH)_(2)dosage,reaction time and stirring rate.The performance stability of the MDEA/PG was verified in multiple regeneration-mineralization dynamic cycle experiments under the optimal conditions.We further confirm the coordinated mechanism of carbonation reaction between CO_(2)and Ca(OH)_(2)using X-ray diffraction(XRD)and transmission electron microscope(TEM).The desorption-mineralization experiment was performed in a flask with three necks respectively.Acid titration was used to measure the CO_(2)loading of the liquid sample.XRD and TEM were respectively used to determine the composition of solid products and observe the micromorphology of carbonated products after regeneration.The CO_(2)loading,Ca(OH)_(2)dosage and stirring rate were the three key factors influencing the uptake of desorption rate.The optimal desorption conditions were CO_(2)loading 0.8 mol/L,Ca(OH)_(2)dosage 1:1,reaction time 20 min,stirring rate 800 r/min,and under these conditions,their desorption rate was 83.68%.The results of multiple desorption-mineralization cycle dynamic experiments showed that the regenerated solution of MDEA/PG desorbed by calcium method has good reusability.The results of X-ray diffraction and transmission electron microscope after carbonation also confirmed that Ca(OH)_(2)can effectively mineralize CO_(2)and regenerate MDEA/PG.The chemical regeneration process can eff
作者
张卫风
李娟
王秋华
Weifeng ZHANG;Juan LI;Qiuhua WANG(School of Civil Engineering Architecture,East China Jiaotong University,Nanchang,Jiangxi 330013,China)
出处
《过程工程学报》
CAS
CSCD
北大核心
2021年第3期353-362,共10页
The Chinese Journal of Process Engineering
基金
国家重点研发计划项目(编号:2016YFC0209300)。
关键词
二氧化碳
氢氧化钙
矿化
解吸率
再生工艺
响应面分析
carbon dioxide
calcium hydroxide
mineralization
desorption rate
regeneration process
response surface analysis
