Chemical Looping Partial Oxidation Process For Syngas Production

The chemical looping partial oxidation process is developed for the efficient conversion of gaseous and solid fuels into syngas via partial oxidation. The chemical looping partial oxidation process converts the fuels into high purity syngas with flexible H2:CO ratio that is suitable for downstream fuel or chemical synthesis. In the chemical looping partial oxidation process, the fuels are partially oxidized in the reducer reactor by the oxygen carrier to generate high purity syngas. The reduced oxygen carrier is regenerated in a fluidized bed combustor via the oxidation reaction with air. Compared to the conventional syngas generation processes, the chemical looping partial oxidation process eliminates the need for additional steam or molecular oxygen from an air separation unit (ASU), resulting in an increased cold gas efficiency and decreased fuel consumption. The chemical looping partial oxidation process features the combination of an iron-titanium composite metal oxide (ITCMO) oxygen carrier and a co-current gas-solid moving bed reducer reactor. The ITCMO oxygen carrier is selected for the chemical looping partial oxidation process due to its desired thermodynamic and kinetic properties. Theoretical analysis aided by a modified Ellingham Diagram illustrates that syngas production is thermodynamically favored in the presence of ITCMO oxygen carrier. The co-current moving bed reducer design provides a desirable gas-solid contacting pattern that minimizes carbon deposition while maximizing the syngas yield. Experimental studies in a fixed bed reactor and a bench scale reactor successfully demonstrate the production of high purity syngas from methane and biomass with the combination of moving bed reducer and ITCMO oxygen carrier. Further scale-up of the chemical looping partial oxidation process is demonstrated in an integrated sub-pilot scale reactor system using non-mechanical gas sealing and solid circulation devices. A dynamic modeling scheme is developed for studying the transient behavior and the control of the chemical looping system. A hierarchical control system based on sliding mode control concept is developed for the chemical looping technologies to simplify process operation.