Layered double hydroxides for CO2 adsorption at moderate temperatures: Synthesis and amelioration strategies

Curving the CO2 atmospheric levels is one of the challenges of this century, given its direct impact on climate change. Of the several strategies of CO2 capture and storage, sorption-enhanced water-gas shift (SEWGS) process, a combination of CO2 adsorption and the water-gas shift reaction, has been appointed as one of the most promising techniques due to is low energy consumption and high efficiency. SEWGS operating settings at both moderate temperature (200-450 degrees C) and high pressure (more than 10 bar) bring the need to find an adsorbent capable of working at these conditions. Calcined layered double hydroxides (LDH) have been proven to give the best results in this range of pressure/temperatures even though its performance can be greatly improved. Herein, a state-of-art of the research accomplished up until now is presented. Several strategies can be followed to improve the adsorbents performance: the synthesis method, LDH composition, modifications employed to promote their adsorption capacity or how the adsorption conditions can affect their efficiency.

Automated summary

This article summarizes the challenge of curving the CO2 atmospheric levels and introduces sorption-enhanced water-gas shift (SEWGS) process as one of the most promising techniques for CO2 capture and storage. SEWGS operating settings at moderate temperature and high pressure require finding an adsorbent capable of working under these conditions. Calcined layered double hydroxides (LDH) have been proven to be the best choice in this range of pressure/temperatures, although their performance can be further improved. The article presents a state-of-art of the research accomplished so far.