关键词: 二氧化碳捕集, 吸收, 再生, N,N-二乙基乙醇胺, 溶解度, 热能

Abstract:

The major drawback of using amine for carbon dioxide (CO₂) capture is the contradiction between lower regeneration heat duty and high CO₂ absorption rate. One way to overcome this problem is to develop an alternative absorbent with improved performance of sorption and desorption CO₂, which can make energy consumption decrease. A quick method was used for selecting potential solvent systems for CO₂ capture by experimental study in this paper. The analysis and comparison were made based on CO₂ loading during sorption and desorption, the absorption/stripping rate, cycling capacity, relative heat consumption and so on. It is demonstrated that aqueous N,N-diethylethanolamine(DEEA) solution is of better absorption/stripping performance for CO₂ capture, which can be presented in terms of equilibrium solubility, overall mass transfer coefficient(K_Ga_V) and regeneration heat consumption, and these parameters were experimentally measured with relevant setup. The results show that the equilibrium solubility of CO₂ in DEEA solution increases with rising of CO₂ partial pressure and decreases with the increase of solution concentration; the K_Ga_V increases with rising of liquid temperature and energy consumption; and the regeneration heat duty decreases with lean CO₂ loading and increases with rich CO₂ loading. Due to the high performance of DEEA, it could be a promising alternative solvent for CO₂ capture.

Key words: CO₂ capture, absorption, regeneration, N,N-diethylethanolamine, solubility, heat duty