The development of computationally efficient, accurate, and stable dynamic reduced order models of Shell Entrained-flow gasifiers would help to better understand the influence of design variables, feed-stocks, and processing conditions on the operating performance of the reactors. This work presents a novel dynamic model of a commercial-scale Shell entrained-flow gasifier for on-line process simulation and soft-measurement of relevant process variables. A dynamic mathematical model of the reactor is developed to obtain real-time performance data of some unmeasurable variables and assess dynamic performance of the reactor under different operating conditions. The model consists of several sub models for devolatilization and combustion, gasification, slagging, and heat transfer. To validate the model, the simulation results are compared with the literature data. Sensitivity analysis is further performed for process optimization. Furthermore, dynamic characteristics is analyzed and optimal operational strategies for industrial Shell entrained-flow gasifier is obtained by optimizing the ratio of oxygen with carbon and the ratio of coal with carrier CO2. (C) 2018 Elsevier Ltd. All rights reserved.