Study on a Coupling Reactor for Catalytic Partial Oxidation of Natural Gas to Syngas

In the current paper, engineering issues for catalytic partial oxidation of natural gas to syngas have been investigated in a pilot plant. In contrast to the microreactor for catalyst evaluation, for a large scale fixed bed reactor operated under high temperature and pressure, attentions should be paid to: introduction method of feeding gases, preheat temperature of feeds, and the coupling of exothermic oxidation reactions with endothermic reforming reactions. As indicated by thermodynamic calculations at a pressure of 2.0 MPa, the reaction temperature should reach at least 1273 K in order to obtain a yield of CO higher than 80 percent. To reach such a high reaction temperature under adiabatic conditions, the feeding gases need to be preheated to a temperature within the range of 773-923 K. With safety considerations of explosion potential, a newly designed nozzle that can premix reactant gases well and thus is suitable for natural gas catalytic partial oxidation process, has been adopted in this pilot unit. A thermally coupled fixed bed reactor is then proposed and proved to be feasible based on thermodynamic calculations and experimental validations.