Energy, economic, environment assessment and process safety of methylchloride plant using Aspen HYSYS simulation model

Abstract

Methyl chloride is the starting material for various chemicals of industrial importance. Because of its toxic, flammable, and explosive nature, safety is also equally important. Based on its industrial importance and safety issues, this research focused on improving efficiency and process safety. In this research, a model simulating the methyl chloride production process through hydrochlorination of methanol is investigated. Using the simulation model results an attempt has been made to improve the methyl chloride production process plant's efficiency in the aspects of energy, economy, safety, and sustainability using process integration. Energy analysis improved the total utilities saving potential up to 36% by adding two new heat exchangers to the existing design. The payback period is reported as 0.63 years. Product cost is reduced by 2.78 USD per ton, Greenhouse gas emissions reduced by 26%, and carbon tax by 26.34%. The location of the pressure safety valves, orifice sizes are calculated for the entire process plant and the storage tank. A quantitative risk assessment was performed by hazard modeling studies using the ALOHA modeling tool for methyl chloride leak from the storage tank. The safety margin calculated is 1900 m. The results of this research can be implemented in process engineering design. The process design methodology using process integration and hazard modeling tools by integrating the energy, economic, and safety approaches at the initial design stages itself is useful to design efficient new plants and to increase the profitability and the safety of the existing methyl chloride production plants.