Abstract: In order to meet the different water demands of ethylene oxide (EO) reabsorption system, EO purification system and ethylene glycol (EG) reaction system for the EO reabsorption tower, the amount of dilution water from de-aldehyde line is adjusted to meet the EO concentration requirements of the feed to EG reactor (R-520) on the premise of guaranteeing the absorption of EO, with the aim of meeting the optimum EO concentration of the feed to EO purification tower. ASPEN simulation analysis shows that, based on the patented technology data and the design data of the internals of EO purification tower, and combined with the actual operation data of the EO/EG plant, the EO concentration of the feed to EO purification tower is increased from 8.9％ to 10％ (case 1)/11.18％ (case 2) by reducing the amount of absorption water in the reabsorption tower from design value 381.4 t/h to 333.7 t/h (case 1)/295.7 t/h (case 2), achieving an additional EO production of 27 kt/a (case 1)/56 kt/a (case 2), calculated according to 8,000 hours, without increasing the feed load of EO purification tower.

Key words: EO/EG plant, EO purification, amount of absorption water, reabsorption system, simulation optimization