Quality Improvement Of Acetone Product And Wastewater Treatment Of Phenol Production

Phenol and acetone are important chemical products. Phenol/aceton unit in the Dyestuff Plant of Jilin Petrochemical Company is a supporting sector for 30kt/a ethylene plant.The objective of this paper is to improve the quality of acetone and treat the waster water efficiently.The producing capacity of phonel/acetone was enlarged to 12kt/a by two-stage process modification for the purpose of lowering manufacturing cost and improving product quality. Due to the unchanged acetone rectifying system, the quality of acetone could not meet the demand for product specification, and the process needed to be modified.In the refinery process of acetone, two rectifying columns were renewed to increase the handling capacity and solve the problems of higher acetone content in wastewater.An independent vacuum system was applied to rectifying column for refined acetone. Condensate of jet steam was refluxed into the column for for refined acetone. The inherent condensate of jet steam was supplied as process water for the column for raw acetone, in which the tail gas was vented to the column for refined acetone. The operating pressure was decreased by 10kPa in the column for raw acetone and decreased by 20kPa in the column for refined acetone in order to obtain higher separation efficiency.Combined with wastewater recovery of washing tower for oxidation feeds and enlargement the diameter of alkaline tower for extract oil, the acetone content in the effluent from the bottom of the column for refined aecton was decreased from 0.28wt% to 0.01 wt%.Under the condition of unaltered discharged waster water, the organic material in exhaut gas was reduced from 1520mg/m3to 120mg/m3, and the COD was decreased from 8000～10000mg/L to 2500mg/L through the spot-source treatment method.