Integrated Energy Efficient CO2 Removal System via Alkali-based Sorbent with Isopropanol System

Abstract

Traditional carbon dioxide (CO2) capture technologies use amine-based sorbents that are very energy-intensive and result in secondary environmental pollution originating from amine degradation. In this work, a low temperature, energy-saving, and environmentally friendly CO2 capture method has been investigated using potassium bicarbonate-alcohol-H2O mixtures as sorbents. The addition of alcohol, particularly isopropanol, to the potassium bicarbonate solution can significantly increase CO2 desorption and capture capacity. The absorbent containing 40 wt% (~72 g) isopropanol, ~20 g potassium bicarbonate, and ~108 g H2O proved to be the most effective for capturing CO2. The IPA-H2O solution resulted in 2.09 mmol of CO2 desorption within 1000 s and a total of 19 mmol of CO2 desorbed by the end of the experiment, which was higher than the other alcohols investigated. This research demonstrates a catalytic CO2 capture route with the potential to be economical, environmentally safe, and energy-efficient.