Comparative life cycle assessment on zeolitic imidazolate framework-8 (ZIF-8) production for CO2 capture

Metal-organic frameworks (MOFs) combine the advantages of both organic and inorganic materials. Among the synthesized MOFs, ZIF-8 is promising for CO2 capture, raising the need for its sustainable production. The life cycle assessment (LCA) of various ZIF-8 synthesis methods such as solvothermal (DMF), solvothermal (MeOH), microwave, sonochemical, mechanochemical, dry-gel conversion and aqueous system was investigated. The findings indicated that the seven production methods have the highest impact on marine ecotoxicity, followed by human toxicity non-carcinogenic, and terrestrial ecotoxicity among the 18 categories of evaluation studies. The main contributor towards environmental degradation was the solvent for washing, N, N-dimethylformamide (DMF) in most of the methods. It is also revealed that replacing the solvent of DMF with methanol remarkably reduced the influence on human health, ecosystem and resources in the solvothermal (MeOH) method as compared to the solvothermal (DMF) method. As a whole, the mechanochemical method has the least impact on the environment because it has fewer production steps and is easy to operate. Therefore, this work delineates comprehensive environmental influences of different ZIF-8 synthesis methods to lay the groundwork for its mass and sustainable production.