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

Abstract

The features of steam reforming of a hydrocarbon mixture containing 71.8% СН4, 15.6% С2Н6, 10.2% С3Н8, and 2.4% С4Н10 in a membrane reactor with a 30 μm 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 H2 and CO2 increases and the yield of byproduct methane and carbon deposits decreases. With an increase in the rate of H2 recovery from the reaction mixture by permeate evacuation, the degree of conversion by the water gas shift reaction yielding H2 and CO2 increases. Under optimal conditions (773–823 K, 1800 h−1, permeate evacuation), high purity H2 is formed in an amount of about 0.8 mmol/(min gcat) and more than 80% of H2 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 gcat) and 90% of H2 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.