Identifying Promising Covalent-Organic Frameworks for Decarburization and Desulfurization from Biogas via Computational Screening

Efficient removal of hydrogen sulfide and carbon dioxide is essential for biogas purification, which is still a long-standing challenge economically and environmentally. Recently, covalent-organic frameworks (COFs) have become competitive candidates for acid gases capture. In this study, high-throughput computational screening of a database containing 382 computation-ready experimental COFs were employed to establish structure-performance relationships and to identify the top-performing materials for H2S and CO2 separation from biogas (H2S/CO2/CH4) under dry operating conditions. By using adsorbent performance score and the sorbent selection parameter as evaluation metrics, the calculated results show that the best material is significantly better than many benchmark materials reported so far. Further, we investigated the adsorption and separation performance of the modified materials in sulfur and carbon capture from ternary gas mixtures. The results indicated that the existence of favorable organic linkers and micro pores played a significant role in promoting the adsorption of H2S and CO2. This work is anticipated to provide a useful guidance for the design of new materials with high performance for decarburization and desulfurization from biogas.