MDEA+MEA/DEA混合胺液脱碳性能实验研究

An experimental study of absorption and desorption of blended amine solutions MDEA+MEA/DEA for natural gas decarburization

混合胺液脱碳法具有吸收能力强、反应速度快、适用范围广、再生能耗低等许多优点,得到了越来越多的关注。为此,采用带有磁耦合搅拌的高压反应釜,进行了不同浓度配比MDEA+MEA、MDEA+DEA混合胺液对CO2的吸收与解吸实验研究。结果表明:①向2.0mol/L的MDEA中加入1.0mol/L的MEA,混合胺液对CO2的吸收解吸综合性能才有显著改善;②MDEA/DEA配比为2.0/1.0时CO2吸收反应很快达到平衡,但该配比在酸气负荷较高的情况下CO2吸收速率较低;③MDEA/DEA配比为2.6/0.4的混合胺液较MDEA单一胺液对CO2的吸收性能并无明显改善;④2.3/0.7配比的MDEA+DEA混合胺液对CO2的吸收负荷与CO2吸收速率均保持较高水平;⑤向MDEA中添加DEA对其CO2解吸性能的改善作用并不明显,只有2.0mol/L的MDEA+1.0mol/L的DEA混合胺液CO2解吸性能稍好,但不如相同配比的MDEA+MEA混合胺液。该成果为天然气脱碳胺液的配方优选和脱碳工业装置的设计提供了基础数据。

Recently, more and more attention has been paid to the decarburization by the mixed amine solutions because of this method＇s big adsorptive capacity, high reaction rate, wide application scope, low energy consumption for regeneration, and so on. In view of this, an experimental investigation was made into the CO2 adsorption and desorption performances of the blended amine soIutions （MDEA ＋ DEA） at different concentration ratios in a high-pressure reactor with magnetic coupling stirring. The following findings were achieved. First, only if the concentration ratio between MDEA and MEA is 2.0/1.0, the CO2 adsorption and desorption performance of the blended amine solutions will be significantly improved. Second, when the ratio between MDEA and DEA is 2.0/1.0, the CO2 reaction will soon reach the equilibrium but the CO2 adsorption rate will be rather low especially under a high content of sour gas; when such a ratio is up to 2.6/0.4, the CO2 adsorption performance will not be obviously improved compared with the single amine solution of MDEA; and when such a ratio reaches 2.3/0.7, the CO2 adsorption and rate will be both kept at a high level. Third, when the ratio between MDEA and DEA is 2.0/1.0, the blended amine solution will have a moderate CO2 desorption capacity but not as good as the blended MDEA and MEA solution at the same ratio. This study provides basic data for the optimal formula of decar- burization and the design of a decarburization industrial plant.