A molecular-level kinetic model was developed for a plasma-arc municipal solid waste (MSW) gasification unit. The kinetic model included both MSW and foundry coke. The components included in the MSW kinetic model were biomass and four common plastics, detailed in earlier reports. The relative amounts of these components can be optimized for experimental ultimate analyses using an in-house tool, the MSW Bulk Composition Solver. The reaction chemistries included detailed pyrolysis and gasification chemistry, totaling 1628 reactions and 433 molecular species. The kinetic model used Arrhenius rate laws and contained a material balance for each species in the model. The model of coke gasification included 10 reactions of surface atoms with oxygen and carbon dioxide. The reaction rates were modeled using both surface diffusion and intrinsic kinetics. The plasma-arc gasifier was simulated using three zones for MSW, combustion, gasification, and freeboard, and a separate zone for coke gasification. Each bed was simulated using idealized chemical reactors with independent conditions. The simulation of the gasifier was organized in a user-friendly application, organizing measurable inputs and outputs. This application allowed for trending studies, investigating the effects of the equivalence ratio, MSW composition, and relative sizes of combustion and gasification zones. The results provided insight into the effects of these variables on tar production, tar composition, and quality of produced syngas.