Track: Modeling and Simulation

Abstract

This work investigates the influence of tire subsidy on the minimum selling price of methanol and electricity produced from a polygeneration process utilizing waste tires as feedstock. Waste-to-energy and chemical processes are often not cost-competitive to fossil-based processes due to high carbon taxes, poor or lack of subsidies, and low thermal efficiency. However, since waste tires are an environmental hazard, waste tire conversion processes must be provided with competitive subsidies or levies to make them competitive with fossil-based fuels. This study developed two process models to evaluate the potential to produce electricity and methanol from waste tires. Aspen Plus and Aspen Hysys were used to simulate the processes' detailed heat and material balance. The process modeling results, including the composition, flow rate, temperature, pressure, and enthalpy of different streams, were used to determine the sizes and cost of the process units and related equipment. A high-level economic model was prepared to evaluate the economic viability of the two processes. The actual selling price of methanol and electricity was estimated by setting the NPV equal to $0. A minimum government subsidy of 0.115 $/kg is required to make the process economical and cost-competitive to fossil-fuelled plants. With the subsidy, the minimum selling price for electricity would be $ 0.098/kWh and that of methanol at $420/ton.