Numerous chemical reactors are known in the art, including batch chemical reactors, flow chemical reactors and a variety of other chemical reactor configurations. These chemical reactors have a number of advantages to scale up production of products from a set of reactants. Such advantages include improved thermal and mass transfer, easier scale-up, and safer operation. Many industrially relevant reactions involve gaseous reactants, either dissolved in the reaction solvent or bubbled through the solvent. In many cases, given the low solubility of gases in most liquids, the gas is usually bubbled through the reaction solvent, and the reaction happens at the gas-liquid interface. Often a heterogeneous catalyst is used to accelerate the reaction. In this case, the reaction occurs at the triple-phase boundary between the gaseous reactant, liquid solvent/reactants, and solid catalyst. Controlling this triple-phase boundary is desired for controlling the reaction rate and selectivity for reactions involving gaseous reactants and solid-state catalysts.
Several approaches are known in the scientific literature for controlling the liquid-gas interface in flow reactors. In one approach, gas and liquid streams are flowed together at carefully controlled pressures, allowing for the formation of annular or plug flow gas-liquid mixtures. Falling film reactors, where a gaseous reactant flows past a thin film of liquid that is being dragged by gravity, have also been implemented. Additionally, designs incorporating coaxial tubes consisting of gas permeable membranes or meshes have been used to control the mixing and interface between gaseous and liquid reactants.