Process intensification of the rWGS reaction by a perovskite-based catalyst
Christoph Markowitsch, Marion Andritz, Lorenz Lindenthal, Thomas Cotter, Hedda Drexler, Christoph Rameshan, Markus Lehner
Abstract
• Comparison of nickel, perovskite and Al 2 O 3 catalysts for rWGS reaction. • Quartz-glass reactor setup for temperatures up to 950 °C and pressures up to 8 bara. • Impact of operating conditions on CO and CH 4 formation for four catalysts. • Identification of optimum operation conditions to minimize CH 4 and maximize CO in product gas. The reverse water gas shift (rWGS) reaction represents a key technology for the utilization of CO 2 . This study presents experimental results which compare the performance of a commercially available nickel catalyst, two novel perovskite catalysts and Al 2 O 3 . In addition to the variations of the input gas composition, the operating conditions have been adjusted between 550 and 950 °C and 1 to 8 bara. The results reveal, on the one hand, that the nickel catalyst achieves thermodynamic equilibrium, resulting in high selectivity toward CO formation at elevated temperatures (950 °C) and pressures up to 6 bara. Higher catalyst loads suppress methane formation at certain operating points. On the other hand, the perovskite catalyst prevents methane formation even at low temperature (550 °C) and higher pressures up to 8 bara favor the CO formation. In consequence, methane formation is limited to less than 2 vol-% at 650 °C and 8 bara and the CO content in the product gas is significantly higher compared with the nickel catalyst. Al 2 O 3 also shows catalytic activity and approaches to thermodynamic equilibrium at high temperature (950 °C) and 6 bara. The investigated novel perovskite catalysts have the potential to intensify the rWGS reaction towards a simpler reactor design and a highly efficient operation, also on a large-scale basis.