Continuous manufacturing of metal organic materials (MOMs):

Metal organic materials (MOMs) are porous materials that have been under research interest for approximately 25 years. These materials have attracted interest since their discovery due to their physical and chemical properties, including structure flexibility, porosity, thermal stability, and adsorption capability. These characteristics are essential in several manufacturing fields, including catalysis, gas adsorption, gas separation, chemical sensors, and drug delivery. The typical pathway for the synthesis of MOMs is a small-scale batch methods that involve pre-treatment of the raw materials, followed by solvothermal synthesis, then pre-treatment of the obtained crystals. These conventional synthesis routes limit the scale-up of MOMs due to challenges such as solvent toxicity, cost of production, and synthesis time. Therefore, it is important to find new non-conventional synthesis routes such as the continuous synthesis approach. Continuous manufacturing is a technique that involves synthesizing the material in a continuous mode without interruption of the process and can be supported by several auxiliary tools, such as real-time monitoring and process control. The synthesis can be done in a single step without stopping the process, as well as reducing the manufacturing time and materials involved. This broad definition includes any type of production process or industry. Integrating continuous manufacturing techniques into the synthesis of MOMs is to develop an engineering approach to shift MOM synthesis from batch synthesis with a significant consumption amount of time, energy, and solvents into a single-step approach with minimum time and a nearly zero-solvent approach. This is in order to meet market demands for MOMs and implement them in industrial applications such as gas storage and separation. This study has investigated two of continuous approaches, such as spray drying (SD), which is a solvent-based technique that has been used to dry and synthesize materials and twin screw extrusion (TSE) as an alternative, successful solvent-free technique.