Optimization and techno-economic evaluation of an integrated process route for the synthesis of vinyl chloride monomer

Abstract

Vinyl chloride gas is a clear and non-irritating compound, often condensed into a liquid state for storage and transportation purposes. Its primary utilization revolves around the manufacturing of polyvinyl chloride (PVC), a material that constitutes around 12% of global plastic consumption. This study examines integrated production process routes for VC through simulation, optimization, and techno-economic analyses, combining the process routes of ethylene dichloride and vinylation in a single process route. The steady-state simulation is performed and analyzed statistically using fit regression while subjecting the simulation results to the linear model, quadratic model, and cubic model. Assessing the fitness of the model, the cubic model was found to give the best prediction and fitness of the simulation results owing to its R² value of 98.13%, compared to 98.02% and 75.19% of quadratic and linear models. Performing energy optimization (i.e., minimization) via the pinch analysis reveals that the process route performs excellently well in minimizing energy consumption with total energy savings of 6.916 × 106 W, resulting in 56.34% savings of the actual value of $112.58 million per year. A hypothetical vinyl chloride processing plant's net present value was also assessed, and a sensitivity analysis was conducted to demonstrate the impact of interest rate fluctuations. This demonstrates that an increase in interest rates led to a decrease in net present value. Using a total capital investment and annual production cost summed up to $2.331 millions and annual revenue of $ 0.651 million, resulting in a payback period and internal rate of return values of 3.58 years and 27.94%, respectively, compared with the 6 years and 27% reported in the literature. Therefore, this study's integrated approach and the techno-economic evaluation of the vinyl chloride production process route indicate a promising choice for a sustainable large-scale VCM production plant set-up.