Process simulation, analysis and optimization of a coal to ethylene glycol process

With the rapid development of polyester industry, the increasing demand of ethylene glycol (EG) is in conflict with the shortage of supply in China. Large project of EG production from coal has been receiving more and more attention. However, little work has been done to model and simulate the complete coal to ethylene glycol (CtEG) process, and there is a lack of research analyzing or optimizing its system performance. In this paper, the CtEG process was modeled and simulated to calculate and analyze its mass and energy balance. The models were validated by comparison with industrial data. The element balance and thermodynamic performance of the CtEG process were analyzed to identify the technical bottleneck and provide theoretical support for the actual production. Key parameters were investigated and optimized for increasing the yield of product as well as improving the system performance of the CtEG process. Results indicate that, the process produce 37.50 t/h EG from 118.98 t/h coal. The exergy efficiency of the CtEG process is 30.68%. The coal gasification and EG synthesis units have the greatest potential for decrease in exergy destruction. After optimization, the production and the exergy efficiency of the process is increased by 3.04% and 2.64%.