Coupling pre-reforming and partial oxidation for LPG conversion to syngas

Coupling of the pre-reforming and partial oxidation was considered for the conversion of liquefied petroleum gas to syngas for the feeding applications of solid oxide fuel cells. Compared with conventional two step steam reforming, it allows the amount of water required for the process, and therefore the energy needed for water evaporation, to be lowered; substitution of high-potential heat by lower ones; and substitution of expensive tubular steam reforming reactors by adiabatic ones. The supposed process is more productive due to the high reaction rate of partial oxidation. The obtained syngas contains only ca. 10 vol.% H2O and ca. 50 vol.% of H2 + CO, which is attractive for the feeding application of solid oxide fuel cells. Compared with direct partial oxidation of liquefied petroleum gas, the suggested scheme is more energy efficient and overcomes problems with coke formation and catalyst overheating. The proof-of-concept experiments were carried out. The granular Ni-Cr2O3-Al2O3 catalyst was shown to be effective for propane pre-reforming at 350–400 °C, H2O:C molar ratio of 1.0, and flow rate of 12,000 h−1. The composite Rh/Ce0.75Zr0.25O2-δ–ƞ-Al2O3/FeCrAl catalyst was shown to be active and stable under conditions of partial oxidation of methane-rich syngas after pre-reforming and provided a syngas (H2 + CO) productivity of 28 m3·Lcat−1·h−1 (standard temperature and pressure).