Enhancing energy efficiency in CO2-rich amine solution regeneration using a Cu-modified attapulgite catalysts

In recent years, significant attention has been drawn to the advancement of high-performance solid acid catalysts, which enhance the CO 2 desorption efficiency and concurrently lower energy requirements. Although solid acid catalysts show promise in reducing regeneration energy for amine-based CO 2 capture, achieving an optimal balance between activity, cost, and stability remains a major challenge. Herein a series of solid acid catalysts were prepared by modifying attapulgite (ATP) with various CuO x loading, and the effect of Cu modification on CO 2 desorption performance was compared systematically. The results showed that CO 2 desorption performance of the as-prepared catalysts was in an order of 2/1-CuO x /ATP >1/1-CuO x /ATP >3/1-CuO x /ATP > CuO > ATP. The CO 2 desorption capacity and rate were increased by 194 % and 205 %, respectively, the relative heat duty could be reduced by about 64.5 % by using 2/1-CuO x /ATP to regenerate the rich MEA solution. ATR-FTIR technique was employed to confirm the catalytic effect and a possible catalytic CO 2 desorption mechanism was suggested. Additionally, the catalyst maintained 81 % of its initial CO 2 desorption capacity after seven consecutive absorption-desorption cycles, demonstrating excellent recoverability. This study provides a practical strategy for utilizing efficient, affordable and environmentally benign solid acid catalysts for CO 2 desorption, thereby advancing energy-efficient CO 2 capture technology.