This study presents a reduced order model (ROM) that describes the behavior of a commercial-scale short-residence gasifier which uses a multielement injector feed system. The state-of-the-art injection technology disperses the feed across the cross-section of the gasifier to enhance the mixing efficiency, thereby allowing a reduction in the reactor size and capital cost. A reactor network is integrated into the ROM to capture the laminar and mixing zones formed by each nozzle and subsequently the merging point of the multiphase flow coming from all of the nozzles. The results of the ROM are in reasonable agreement with the limited data reported for a short-residence time commercial-scale gasifier, that is, residence time, carbon conversion, and cold gas efficiency. Moreover, the performance of the gasifier is examined under changes in the operating pressure, number of injectors, flow nonuniformity, and plugging in the fuels injection tubes. The ROM provides valuable insights on the operation of the commercial-scale gasifier and potential safety concerns that can be used to design suitable and safe operation policies for the system. Furthermore, sensitivity analyses on the model, design, and operational parameters are performed to assess the suitability of the model assumptions and identify the most important factors influencing carbon conversion, particle residence time, and temperature profiles.