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 g_cat) 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 g_cat) 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.