Performance and influencing factors of organic amine electrochemical regeneration system

Abstract

In the context of carbon neutrality, the carbon capture, utilization and storage (CCUS) is a key technology to achieve energy conservation and emission reduction. In view of the high energy consumption and degradation of organic amine solutions in the carbon capture process, an electrochemically mediated amine regeneration (EMAR) is a promising carbon capture technology, which uses the complexation between Cu(II) and absorbent to achieve the release of CO2. The CO2 absorption and desorption performance of nine absorbents was measured using the absorption and desorption experimental device. It was found that the primary and secondary amine solutions have better absorption performance than tertiary amines, but the regeneration efficiency is not high under the traditional thermal desorption method, and there is great potential for improvement. The Cu(II) was added directly to the CO2-saturated amine solution, and the solution was found to exhibit excellent desorption properties. Under the same conditions, the cathodic and anode electrochemical parameters of different alcohol amine solutions were tested, and the electrochemical parameters such as polarization potential, current density and solution internal resistance, as well as absorption and desorption performance and raw material cost were comprehensively considered, and the DETA was selected as the research object to continue the exploration of subsequent experimental conditions. The electrochemical reaction device was used to study the 30% DETA aqueous solution saturated with CO2, and the influence of four influencing factors, i.e. electrolyte type, electrolyte concentration, Cu(II) concentration and temperature on the electrochemical reaction process, was explored. It was found that NaBr has a lower corrosion potential among the four selected electrolytes, and the advantage of potential at high concentrations is more obvious, which is more conducive to the reaction. The high electrolyte concentration can reduce the corrosion potential to 0.2 V relative to the absence of electrolyte, and both it and temperature can effectively reduce the charge transfer resistance and increase the reaction rate. In addition, the low Cu(II) load is conducive to the formation of Cu(II) and the desorption of CO2, and the increase of the concentration of Cu(II) in solution will inhibit the oxidation of anode copper to copper ions, which is conducive to the formation of elemental copper and the regeneration of DETA. The study results provide reference data for the engineering application of this technology.

Keywords

• co2 capture
• emar
• deta
• electrochemical
• eis