Study On Hydrogen Recovery Using PDMS/PS Composite Membrane From Catalytic Cracking Dry Gas

Catalytic cracking dry gas contains large amounts of hydrogen, ethylene and other resources, such as the irrational use will result in a waste of resources. Through the study of membrane materials investigation, we selected a suitable experimental membrane materials and preparation methods, obtained a high permeation rate and permeation selectivity composite membrane recipe by orthogonal design, achieved the purpose of recovery of hydrogen from catalytic cracking dry gas.Membrane separation technology has obvious advantages in the terms of gas separation, with its less energy consumption, simple operation, few investment and no pollution, has become a leading subject of concern, and has entered the stage of industrial application.Separation performance of gas separation process mainly depends on the property of membrane. Firstly, the polysulfone is chose as the substrate layer material, prepared polysulfone flat membrane through phase inversion method, and PDMS is as the coating layer material in order to cover the shortage in the dense layer of PS. The PDMS/PS composite membranes were prepared by dip-coating method. The structure and properties of polysulfone membrane, silicone rubber and composite membranes was analyzed by, SEM and TG methods.Secondly, the effects of PS concentration, additive concentration, temperature of the casting solution, the composition of the coagulation bath, the residence time in the air, PDMS concentration, catalyst concentration, cross linking concentration, PDMS coating time, coating thickness on gas separation performance of composite membranes also were discussed. The suitable formula and operation conditions for preparing the composite membrane were found.