Optimal design and operation of a natural gas tri-reforming reactor for DME synthesis

Korea Gas Corporation (KOGAS) is developing a new di-methyl-ether (DME) plant. Syngas is provided by natural gas tri-reforming, in a reactor consisting of a homogenous part where oxidation leads to a temperature increase required for the reforming reactions and a catalytic part where the reforming reactions take place. A first principle model for the tri-reforming reactor is developed. A kinetic mechanism is proposed combining homogeneous gas-phase reactions and heterogeneous catalytic reactions. The proposed model is systematically calibrated and validated with global sensitivity analysis followed by global parameter estimation against concentration measurements of a lab-scale prototype reactor and comparisons of the sensitivity of the outlet as a function of inlet composition and design parameters with experimental results. The validated model is finally used for the optimization of design variables such as length ratio of homogeneous and heterogeneous section and operational variables such as the feed composition.