Pure hydrogen production by steam reforming of methane mixtures with various propane contents in a membrane reactor with the industrial nickel catalyst and a Pd–Ru alloy foil

Abstract

Steam reforming of СН4 mixtures containing 5, 10, and 15% С3Н8 was studied in a membrane reactor with the industrial nickel catalyst and a membrane as a foil 30 μm thick of a Pd–Ru alloy. The reaction was studied at temperatures of 773 and 823 K and the mixture gas hourly space velocities equal to 1800 and 3600 h−1. Experiments were carried out under atmospheric pressure, and both sweep gas (N2) and vacuum conditions in the permeate side were used for Н2 recovery from the reaction mixture. The complete conversion of С3Н8 was observed under all conditions. It is shown for the first time that the main factor determining the influence of propane on the reaction parameters is the rate of Н2 recovery from the reaction mixture. A negative influence of С3Н8 on methane reforming was observed only in experiments using the sweep gas. This fact was proposed to be related to the insufficient СО conversion in the water-gas shift reaction. For vacuum conditions in the permeate side of the membrane reactor, the rate of Н2 recovery from the reaction mixture increases, which increases the CO conversion in the water-gas shift reaction. In this case, the negative effect of С3Н8 on methane reforming is minimum and is almost absent at 823 K. The conversion of methane is 93–97%, depending on the flow rate of the raw materials, and 75–80% Н2 are recovered from the reaction mixture.