The conversion of fossil fuels, by gasification, reforming, or partial oxidation processes is important for the synthesis of hydrogen and syngas for subsequent use in refining, or chemicals and fuels production. In the implementation of these technologies gas-separation steps are needed, especially for the separation of hydrogen. One of the methods for gas separation is membrane technology. The use of membrane reactors (MR) is one of the most promising applications because the combination of reaction and separation can be used to overcome equilibrium limitations in some chemical transformations.It is known that palladium-based membranes are effective materials for hydrogen separation with high permeance and selectivity and high mechanical strength. In the present work a novel membrane preparation technique was used where an electric-field was employed to uniformly deposit Pd nanoparticle seeds on a substrate followed by deposition of ultrathin Pd or Pd-Cu layers on the activated surface by electroless plating (ELP). To increase the membranes' resistance to sulphur poisoning, for the first time phosphorus was incorporated in the structure and the peformance and sulfur resistance of the membranes were evaluated under exposure to a gas mixture of 100 ppm H2S in H2. The presence of phosphorus conferred some structural integrity to the membrane that helped it to regenerate more efficiently under hydrogen flow after it had been exposed to H2S, avoiding the formation of cracks and pinholes.The prepared membranes were used in a membrane reactor (MR) for ethanol steam reforming for hydrogen production, using catalysts such as Co-Na/ZnO.  The reactions were also carried out in in a packed bed reactor (PBR) to evaluate the benefits of employing membranes. Ethanol conversion and hydrogen product yields were significantly higher in the MRs compared to the PBR.

Ultrathin Pd and Pd alloy membranes with phosphorus additive and enhanced sulfur resistance applied in membrane reactors for ethanol steam reforming

247th National Meeting (2014)

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