# US 11,028,035 B2 · Method and device for purifying acetone/water mixtures by means of double-effect distillation > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,028,035 B2 - Document ID: US11028035B2 - Status: Granted - Kind: B2 - Application number: 16/616,163 - Filed: 2018-04-26 - Published: 2020-05-07 - Granted: 2021-06-08 - Earliest claimed: 2017-05-31 - Assignees: Rhodia Acetow GmbH - Applicants: Rhodia Acetow GmbH - Inventors: Andreas Hummel; Thomas Krumrey - Web page: https://patentgrep.com/patent/US11028035B2 ## CPC - C07C 45/82: by distillation - B01D 3/007: {Energy recuperation; Heat pumps} - B01D 3/143: {by two or more of a fractionation, separation or rectification step} - B01D 3/146: {Multiple effect distillation} - C07C 49/08: Acetone - C07C: ACYCLIC OR CARBOCYCLIC COMPOUNDS - B01D: SEPARATION (separating solids from solids by wet methods B03B, B03D; by pneumatic jigs or tables B03B; by other dry methods B07; magnetic or electrostatic separation of solid materials from solid materials or fluids, separation by high-voltage electric fields B03C; centrifuges, vortex apparatus B04; presses per se for squeezing-out liquid from liquid-containing material B30B9/02; treatment of water C02F, e.g. softening by ion-exchange C02F1/42; {arrangements of air intake cleaners in gas turbine plants F02C7/05} ; arrangements or mounting of filters in air-conditioning, air-humidification or ventilation F24F13/28) ## Abstract The invention relates to a method for separating acetone from acetone/water mixtures, according to which a partial flow of the acetone/water mixture is concentrated in a column operating under positive pressure in order to obtain a product with an acetone concentration of at least 80 wt. %, and a partial flow of the acetone/water mixture is concentrated in a column operating under normal pressure. The top product from the column operated under positive pressure is used to heat the bottom product of the column operated under normal pressure, by means of a heat exchanger, and the top product is then introduced into the column operated under normal pressure, above the supply of the partial flow of the acetone/water mixture. This method allows the specific energy demand for acetone separation to be significantly reduced, thereby presenting considerable cost advantages. The invention also relates to a device for carrying out such a method. ## Claims ### Claim 1 A method for separating acetone from an acetone/water mixture, comprising: concentrating a partial first flow of the acetone/water mixture in at least one first column to produce a product having an acetone concentration of at least 80 wt %, wherein the at least one first column is operated under positive pressure; concentrating a partial second flow of the acetone/water mixture in at least one second column, wherein the at least one second column is operated under normal pressure, wherein a top product from the at least one first column is used to heat a bottom product of the at least one second column via a heat exchanger, and wherein the top product is subsequently introduced into the at least one second column above a supply of the partial second flow of the acetone/water mixture. ### Claim 2 (depends on 1) The method according to claim 1, wherein the at least one first column is operated at a positive pressure in the range of 4.5 to 8 bar absolute. ### Claim 3 (depends on 1) The method according to claim 1 further comprising a top product having an acetone concentration of at least 90 wt % is obtained in the at least one first column. ### Claim 4 (depends on 1) The method according to claim 1, wherein the bottom product obtained from the at least one first column is used to preheat the acetone/water mixture introduced into the at least one second column. ### Claim 5 (depends on 1) The method according to claim 1, wherein the at least one first column exhibits 30-60 theoretical plates. ### Claim 6 (depends on 1) The method according to claim 1, wherein the at least one second column exhibits 20-40 theoretical plates. ### Claim 7 (depends on 1) The method according to claim 1 further comprising: concentrating a partial third flow of the acetone/water mixture in at least one third column, wherein the at least one third column is operated under a vacuum, wherein a top product from the at least one second column is used to heat a bottom product of the at least one third column via a heat exchanger. ### Claim 8 (depends on 7) The method according to claim 7, wherein the bottom product from the at least one second column is introduced into the at least one third column below the supply of the partial third flow of the acetone/water mixture. ### Claim 9 (depends on 1) The method according to claim 1, wherein the acetone in the at least one second column is concentrated to a concentration of at least 98 wt %. ### Claim 10 (depends on 1) The method according to claim 1, wherein the at least one second column is operated at a reflux ratio of from 1 to 2. ### Claim 11 A device comprising: at least one first column for separating a partial first flow of an acetone/water mixture, wherein the at least one first column is operated under positive pressure, at least one second column for separating a partial second flow of an acetone/water mixture, wherein the at least one second column is operated under normal pressure, supply lines for the partial first flow and the partial second flow of an acetone/water mixture to the at least one first column and the at least one second column, at least one heat exchanger in fluid communication with a top of the at least one first column and a bottom of the at least one second column configured to enable a transfer of heat between a top product of the at least one first column and the bottom product of the at least one second column, and a supply line for the top product of the at least one first column via which the at least one heat exchanger is connected to an upper part of the at least one second column, wherein the supply line is connected to the at least one second column above the supply line for a partial second flow of an acetone/water mixture. ### Claim 12 (depends on 11) The device according to claim 11 further comprising a condensation device for the top product generated in the at least one second column. ### Claim 13 (depends on 11) The device according to claim 11 further comprising a heat exchanger in fluid communication with the bottom product of the at least one first column and the supply line for the partial first flow of an acetone/water mixture to said column. ### Claim 14 (depends on 11) The device according to claim 11, wherein the device further comprises: at least one third column for separating a partial third flow of an acetone/water mixture, wherein the at least one third column is operated under a vacuum, a supply line for the partial third flow of the acetone water mixture to the at least one third column, at least one heat exchanger in fluid communication with the top of the at least one second column and the bottom of the at least one third column configured to enable a transfer of heat between the top product of the at least one second column and the bottom product of the at least one third column.