Cleaner production of metal-organic framework MIL-101(Cr) for toluene adsorption

Abstract

Metal-Organic Frameworks (MOFs) are a kind of materials with different environmental applications. However, in a sustainable approach, the production must be analyzed from economic, technical, and environmental standpoints. The aim of this study is focused on obtaining a cleaner production of MIL-101(Cr). A multi-criteria decision-making method was applied to consider environmental (Life Cycle Assessment methodology), technical (toluene adsorption experiments), and economic (Monte Carlo simulation) criteria. Optimization of the synthesis process resulted in a MIL-101(Cr) with good textural properties, which behaves as a strong adsorbent suitable for toluene capture (43.44 mmol/g adsorption capacity) at low concentrations (∼2 ppm). The environmental analysis results showed significant impacts in Climate Change > Fossil Depletion > Particulate Matter categories due to toxic solvents and metallic salt. Monte Carlo simulation revealed that toxic solvent also provides an extra cost in MIL-101(Cr) synthesis (30–35 %). Moreover, the results revealed that the cleaner MIL-101(Cr) synthesis presented 64 % minor environmental impact and is 34 % more economical than a conventional MOF synthesis. This research is a step toward a more comprehensive method for synthesizing MOFs for adsorption applications by combining technical, economic, and environmental perspectives.