Patent name: METHOD OF PRODUCING ACETONE PRODUCT WITH HIGH STABILITY TO OXIDATION
Patent Number: Patent No. 2167144
Priority: May 12, 1998
May 20, 2001
Acetone is produced by its separation from products of decomposition of cumene hydroperoxide by multistep fractionation. Acetone flow is separated as overhead product in the first column and phenol is obtained as bottom product. Acetone flow is directed to partial condenser in which weight ratio of vapor and condensed flows ranges from 1:0.02 to 1: 0.1. Condensed phase is directed to the reflux of the first column. Noncondensed products are directed to the second column of separation by fractionation to which supplied simultaneously above feed tray is aqueous solution of sodium hydroxide in terms of 100% NaOH from 0.0036 to 0.006 t per one ton of acetone depending on required value of permanganate test from 10 to 70 h. Drawn as everhead product in the second column is aldehyde fraction directed to neutralization stage and flow containing acetone and water is withdrawn as side-cut distilled in vapor phase and directed to partial condenser to separate into liquid and vapor phase with weight ratio of phases from 1:10 to 1:100, respectively. Vapor phase of partial condenser is directed to the third column where acetone product is drawn off as overhead product. Bottom product of the third column presenting acetone aqueous solution is returned to the second column. Liquid phase of partial condenser is treated with solution of alkali and returned, either, to the second column, or to stage of neutralization of products of decomposition of cumene hydroperoxide. The second version of method embodiment provides for one column for separation of commercial acetone from vapor phase of partial condenser after the first rectification column. In this case, acetone is drawn off as column overhead product and directed to partial condenser for production in it of liquid and vapor phases in ratio from 1:50 to 1:150, respectively. Vapor phase is condensed in cooler with obtaining of acetone product, and liquid phase is treated with aqueous alkali solution and subsequent return of produced raw acetone to the second column, or to point of feed or reflux. Technical effect of the invention is production of acetone product with high stability to oxidation.