The 2016 senior class at the University of Houston is designing a propylene glycol plant by non-catalytic hydration of propylene oxide at high temperature and pressure. This design has a capacity of 90,000 metric tons/year and achieves a specified production quantity, product selectivity, and product quality for mono-, di-, tripropylene glycol.
Alternative process flow diagram, heat and material balances, equipment sizing, and economic evaluation are presented. Computational tools including VBA and MATLAB routines are used for the flash calculations, reactor and column design equations. Moreover, commercial software packages including Aspen Plus and CHEMCAD are used for parametric and topological optimization.
Both isothermal and adiabatic operation is considered for a various reactor configurations. Multi-effect evaporators are employed to concentrate the glycol mixture and recycle the excess water. The glycols products are then separated to meet specifications via vacuum distillation. Ultimately, equipment performance, raw material and utility usage, optimum heat integration and HSE considerations are integrated to provide a technically feasible, profitable, and socially responsible design.