Oxalic acid as a hydrogen donor and its promotion on the catalytic viscosity reduction of heavy crude oil over Cu/FeOx catalyst

Abstract

In this paper, Cu/FeOx composite catalysts were successfully synthesized by a hydrothermal method followed by a hydrogen gas reduction and were used as the catalysts for the cracking of heavy crude oil and the simultaneous low-temperature water–gas swift (LTWGS) reaction. Oxalic acid was used to generate the reactants (i.e., CO and H2O) of LTWGS reaction in-situ through its decomposition under the reaction temperature (200 ℃) of the heavy crude oil cracking. Cu0 in Cu/FeOx acted as a catalyst of the LTWGS reaction (CO + H2O ↔ CO2 + H2) and α-Fe2O3 in Cu/FeOx acted as a catalyst for the cracking of heavy crude oil. In-situ H2 coming from the LTWGS reaction promoted the catalytic viscosity reduction rate of heavy crude oil via inhibiting the radicals from recombining. This work gives a new, economical and efficient approach to supplying H2 for heavy crude oil upgrading through the in-situ LTWGS reaction of the decomposition products of oxalic acid.