Synergistic removal of HCl and Hg0 in pyrolytic waste plastic gas on Ca and Co loaded carbon aerogel at room temperature

Abstract

In this study, a green synthesis route was developed to prepare Ca and Co oxides supported carbon aerogel from renewable alginate. The sodium alginate was adopted as a template and carbon source, and a hydrogel with a three-dimensional and core-shell structure was chelated by introducing calcium and cobalt bimetals. The synthesized CaCo oxides supported carbon aerogel can completely remove Hg0 in the HCl-containing waste gasification gas at room temperature. The Hg0 adsorption capacity on the 4Ca-1Co/CA adsorbent is as high as 4.02 mg/g when the 5% breakthrough occurs. At a 20% breakthrough of HCl, the captured amount of HCl could reach 175.37 mg/g. We concluded that the introduction of calcium and cobalt on the adsorbent provides sufficient active sites for the removal of HCl in a large amount, at the same time, the excellent oxygen supply capacity of Co species in an oxygen-free atmosphere can form active chlorine sites, which is conductive to enhance the removal of Hg0. Additionally, the 4Ca-1Co/CA adsorbent has the characteristics of wide temperature window and wide application range of space velocity, which can meet the needs of various working conditions.