Industrial Preparation And Application Of PDMS/PVDF Composite Membranes In The Gasoline Vapor Recovery From Gas Station

While destroys our environment,the volatilization of gasoline vapor also consumes a lot of energy.Therefore,the recovery of gasoline vapor has important practical meaning,and the recovery techniques of gasoline vapor has a broad prospect.As a new generation technology of gasoline vapor,membrane separation technologies is getting more and more attention,contrast to old process,it has a large number of merites,for instance efficient,low-energy,pollution-free and lowcost.In this paper,PVDF porous support was produced by phase conversion method,analyzed the properties of membrane by characterization,and the industrial production conditions of PVDF membrane were optimizedPDMS/PVDF composite film was prepared by coating PDMS solution on PVDF substrate,the impacts of viscosity of prepolymer,the dosage of cross-linking agent and the viscosity of PDMS casting liquid on the properties of membrane were investigated,and the optimum conditions of PDMS/PVDF composite membrane in industrial production were determined.An on-line experimental equipment and analysis method for gas separation performance of composite membrane was established.The separation test of C3H8/N2 mixture was carried out,the impacts of production criteria(the use level of cross-linking agent,the temperature of cross-linking reaction,The length of cross-linking reaction,the thickness of separation layer)and evaluation conditions(the temperature,the pressure,the velocity of feed,the length of experiment)were researched.Through the curve found that when the dosage of cross-linking agent increased,the total flux tended to be flat after decreased,and the separation factor tended to be flat after increased.With increasing the temperature of cross-linking reaction and length of cross-linking reaction,the total flux minished,and the separation factor enlargemented.When the thickness of separation layer augmented,the total flux minished memorably,and the separation factor didn't transform memorably When the temperature increased,the total flux and separation factor both showed a decline trend.When added to the pressure,the total flux and separation factor both showed an upward trend.When add to the velocity of feed,the total flux and the separation factor both showed an upward trend.At the temperature of 25?,the pressure of 0.5MPa and 20mol%C3H8 in the feed gas,the total flux achieved 189.62L/m2h and separation factor reached 25.73.VOCs/air separation experiments was carried out to confirm the general effectiveness of the membrane for various hydrocarbons and their derivatives.A program which recovery of gasoline vapor in gas station was implemented.The equipment has good stability in the long-term operation of gas station,the recovery rate of gasoline vapor reached 98.66%.Environmental effectiveness was outstanding,brought considerable economic effectiveness simultaneously...