Research and application of oil-free screw compressor in low-pressure exhaust gas recovery from coal to ethylene glycol production

This article mainly focuses on the research of the recovery of low-pressure exhaust gas containing DMC from coal to ethylene glycol using oil-free screw compressors. Key technical issues such as compressor process flow, screw compressor selection, injection medium selection, circulating injection volume, methanol replenishment volume, waste liquid discharge volume, and the relationship between shaft power and exhaust temperature have been proposed and solved. Through simulation software ASPEN, the optimal outlet operating temperature (compressor exhaust temperature 78 °C) was obtained under design conditions (inlet state 0.002MPaG/45 °C, exhaust pressure 0.25MPaG). Based on the comparison of data from actual operating devices, the reliability of the research has been demonstrated, which can be used to guide the application of screw compressors in the field of low-pressure exhaust gas recovery from coal to ethylene glycol containing DMC.