Application of a Gas-Liquid Mixing Pump in Biogas Purification and the Co-production of Nano Calcium Carbonate

CO₂ removal is one of the key technological requirements in biogas purification. A technique using a gas-liquid mixing pump to capture CO₂ and co-produce nano calcium carbonate was devised and tested in this work. The characteristic curves and CO₂ absorption efficiency of the pump were investigated. The CO₂ content of the end gas in all experiments was less than 2%, and the calcium carbonate samples showed that calcite was produced with a favorable particle size. A solution was proposed to deal with gas inlet blockage by preparing polyphenylene sulfide (PPS)-polytetrafluoroethylene (PTFE) coating. The coating had superhydrophobicity, self-cleaning ability, a unique microstructure, and good adhesion to the substrate. The gas inlet coated with PPS-PTFE could remain clean for at least 12 h, suggesting that the method used in this work was suitable. This work provides a novel approach for CO₂ absorption and biogas purification.