Production of High-Purity Hydrogen by Steam Reforming of Associated Petroleum Gas in Membrane Reactor with Industrial Nickel Catalyst

The features of steam reforming of a hydrocarbon mixture containing 71.8% CH4, 15.6% C2H6, 10.2% C3H8, and 2.4% C4H10 in a membrane reactor with a 30 mu m thick Pd-Ru alloy foil and the NIAP-03-01 industrial nickel catalyst have been investigated. The reaction was studied in the temperature range of 723-823 K at a steam/feed ratio of 5 and space velocities of 1800 and 3600 h(-1). Comparison with the "nonmembrane" reaction showed that in the membrane reactor, the feedstock conversion to form H-2 and CO2 increases and the yield of byproduct methane and carbon deposits decreases. With an increase in the rate of H-2 recovery from the reaction mixture by permeate evacuation, the degree of conversion by the water gas shift reaction yielding H-2 and CO2 increases. Under optimal conditions (773-823 K, 1800 h(-1), permeate evacuation), high purity H-2 is formed in an amount of about 0.8 mmol/(min g(cat)) and more than 80% of H-2 is recovered from the reaction mixture. As the feed space velocity increases to 3600 h(-1), the yield of hydrogen increases to 1.3 mmol/(min g(cat)) and 90% of H-2 is recovered through the membrane. However, a high conversion of the feedstock into carbon deposits is observed in this case. In general, the results obtained show that it is possible to obtain high-purity hydrogen from associated petroleum gases by optimizing the conditions of steam reforming in a membrane reactor without preliminary isolation of C2+ alkanes from the feedstock.