(553h) Novel SAPO-34 Hollow Fiber Membrane for H2 Separation Under Various Gas Atmospheres at High Temperature

In the current research, a novel SAPO-34 hollow fibre membrane for hydrogen separation was fabricated using seeded secondary growth method. As compared to the conventional tubular membranes, hollow fibre membranes have a great advantage of higher surface to volume ratio, higher gas permeation due to reduced wall thickness etc. To obtain high quality SAPO-34 hollow fibre membranes, zeolite seeding and growing conditions were optimized to achieve a thin and defect-free zeolite layer for high gas permeability and selectivity. In addition, it was found out that membranes calcined under flowing oxygen had significantly higher gas permeability than those calcined under stagnant air. In this research, the membranes were subjected to permeation test of binary gas mixtures such as H₂/CH₄, H₂/CO₂, and H₂/N₂ at both room temperature and elevated temperatures ranging from 25 to 500 ℃. Remarkable H₂ separation performance was achieved in separating a H₂/CH₄ mixture through the SAPO-34 hollow fiber membrane with a maximum H₂ selectivity of 45 at 100 ℃ and a H₂ permeation flux of 10.1*10^-8 mol. m^-2.s^-1.Pa^-1. In addition, H₂ permeation flux increased to 28.9*10^-8 mol. m^-2.s^-1.Pa^-1 with at a temperature of 500℃ while the selectivity dropped to around 25. Due to the good H₂ permeation performance at high temperature, SAPO-34 hollow fiber membrane can be integrated with catalysts to form catalytic membrane reactors for various H₂ production reaction such as water gas shift (WGS) and dehydrogenation of hydrocarbons like propane. This novel catalytic membrane reactor can simultaneously remove hydrogen product, and increase the productivity of the reaction beyond the equilibrium yield.