【作者】 沈洪士；

【导师】 张永春；

【作者基本信息】 大连理工大学 ， 工业催化， 2010， 硕士

【摘要】 CO2作为主要的温室气体,大约占所有温室气体的60%。近年来,随着工业的快速发展,越来越多的化石燃料燃烧以及绿色植被的减少,导致大气中的CO2含量逐年增加。有机胺吸收CO2工艺出现于20世纪30年代,实现工业化后成为工业净化CO2的主要方法之一。本研究通过用Aspen Plus流程模拟软件设计并搭建了胺回收CO2的小型中试装置,考察了不同胺溶液吸收CO2的性能。本实验装置包括吸收塔和再生塔两个部分,并使用填料塔考察吸收剂的吸收效果。实验过程中考察了常压下混合胺吸收剂(20%乙醇胺(MEA)+2%N-甲基二乙醇胺(MDEA)与20%羟乙基乙二胺(AEE)+2%N-甲基二乙醇胺(MDEA))对CO2的吸收与再生效果。并对二者的吸收效果进行对比。同时测得了AEE+MDEA混合胺体系吸收剂脱除空气中体积分数约10%的CO2的体积总传质系数KGav的近似值,并考察了进口气体中CO2摩尔流量、气体流量、液体流量等因素对KGav的影响。实验结果表明,AEE+MDEA吸收效果明显好于MEA+MDEA,并且二者解吸效果相同；体积总传质系数KGav随CO2摩尔流量、气体流量、液体流量增大而增大。由于胺溶液吸收CO2的再生温度均高于100℃,导致胺与水溶液吸收CO2在再生过程中使水大部分蒸发消耗大量能量。因此本研究考察了用沸点比较高的N-甲基毗咯烷酮做溶剂的胺吸收CO2的效果。实验结果表明在相同的胺浓度下水做溶剂吸收CO2的效果高于N-甲基吡咯烷酮。但是用N-甲基吡咯烷酮做溶剂再生能耗明显下降。在工业生产中由于存在胺降解导致吸收剂消耗的问题,本论文采用酸碱中和滴定法测定胺溶液中胺的浓度考察了120℃下MEA吸收剂在氧气,空气以及氧气和CO2同时存在的条件下的降解情况。实验表明通入纯O2、CO2、CO2／O2混合气体、CO2／空气混合气体时不光是O2能引起胺降解,CO2也能引起胺降解。更多还原

【Abstract】 CO2 as the main greenhouse gas, accounting for 60% of all greenhouse gases. In recent years, with the industry’s rapid development, more and more fossil fuel burning and reduction of vegetation, resulting in CO2 increase every year. Amine method for CO2 absorption appeared in the 1930s’,and it has became a major industrial CO2 purification methods after its industrialization.In this study, we used Aspen Plus process simulation software to design and build a small pilot-plant to investigate the performance of CO2 absorption in different amine solutions. The pilot-plant includes two parts(absorber tower and regeneration tower),and we used pecked tower in the two parts.A study of carbon dioxide absorption and regeneration in aqueous amine solutions, consisting of 20%2-(aminoethylamino) ethanol (AEE)+2%N-methyldiethanolamine (MDEA) and 20% monoethylamino(MEA)+2% N-methyldiethanolamine (MDEA) has been carried out in a packed tower. The results showed that the CO2 absorption in 20%AEE+2%MDEA better than 20%MEA+2%MDEA and The CO2 regeneration near the same in both blended amine. Also, The volumetric overall mass transfer coefficient (KGav) of dilute CO2 absorption into AEE/MDEA was measured. The KGav value was evaluated over the ranges of CO2 mole flow rate in inlet gas, overall gas flow rate and liquid flow rate. As a resulte,the KGav could be remarkably improved by increasing CO2 mole flow rate in inlet gas, overall gas flow rate and liquid flow rate.As the aqueous regeneration temperature above 100℃, the evaporation of water in water and amine aqueous at regeneration process, leading to most of the energy consumption. Therefore, this study used a relatively high boiling point solvent (N-methyl-pyrrolidone) to research the amine absorption of CO2. Experimental results show that at the same amine concentration, the absorption of CO2 into the water do better than into the N-methyl-pyrrolido ne. But the regeneration energy consumption decreased with the N-methyl-pyrrolidone as solvent.In industrial production because of the degradation of amine, leading to the absorbent consumption. In this study the concentration of amine was determined by acid-base titration. we researched MEA’s degradation under the conditions of O2, air, CO2/O2 at the 120℃. Experiments show that not only the access of pure O2, CO2/O2 mixed gas, CO2/air mixture can leading to the degradation of ME A, but also the CO2 can leading to the degradation of MEA.更多还原