| 摘要 |
#CMT# #/CMT# Process for treating an aqueous effluent (F1) comprising an aromatic amine and light organic impurities corresponding to a total organic carbon (TOC) content less than 1%, comprises subjecting the flow (F1) to distillation operation designed to obtain a liquid flow (F3) of an aqueous solution of aromatic amine at distillation base, a gas flow (F2) comprising the light organic impurities on distillation head, a liquid flow (F4) of purified water in an area higher than the flow feed (F1). #CMT#USE : #/CMT# The process is useful for treating the aqueous effluent. #CMT#ADVANTAGE : #/CMT# The process does not affect the water flow after the catalytic hydrogenation and is cost effective. #CMT#ORGANIC CHEMISTRY : #/CMT# Preferred Process: The process comprises: heating (F1) at the distillation base in a heat exchanger by withdrawing of the flow (F5) which releases in distillation base and traverses upwards, a heat exchanger which is in exchanger outlet, introduced laterally in the bottom of the distillation column; introducing the aqueous flow (F1) either in liquid form or as steam or as vapor and liquid in the distillation column to one or two levels above the boiler; recovering a flow of aromatic amine (F3) which is an aqueous solution of aromatic amine (0.005-0.2%) in column base; recovering a gaseous phase (F2) comprising of ammonia, light organic impurities and water which is condensed by passing it through a heat exchanger cooled at 100[deg] C-55[deg] C in column head; recovering in condenser outlet a condensed liquid which is a biphasic liquid phase separated in two phases comprising an organic phase (F7) gathering light organic impurities which are sent to the destruction and an aqueous phase (F6) which is optionally recycled on the distillation column; feeding takes place in the column head and usually laterally; drawing of a liquid flow (F4) comprising of water that optionally is recycled in an area higher than the aqueous flow (F1) feed; separating three flows comprising drawing the majority of the liquid flow (F4), the feed flow (F1) (at least 80%) which is purified water disposable without treating in the natural medium laterally, drawing a flow having feed flow (F1) (less than 5%) which is highly concentrated in light organic impurities on top, drawing a flow (F3) mainly comprising the aromatic amine having feed flow (F1) (less than 15%) in the base; concentrating the majority of the organic pollution and ammonia in the flow (less than 5%). Preferred Components: The aromatic amine is of formula (I). The aromatic amine is aniline, toluidine, p-isopropylaniline, chloroaniline, toluylenediamine, p-aminophenol, o-aminophenol, 2,4-difluoroaniline, 3,4-dichloroaniline and 2,4-dichloroaniline. (F1) comprises a mixture of 2,4-toluene diamine and of 2,6-toluene diamine, having resultant impurities of hydrogenation or the cycle benzenic perhydrogenation. (F1) is obtained by catalytic hydrogenation of 2,4-dinitrobenzene and 2,6-dinitrotoluene mixture obtained after the nitration of the toluene leading to an aqueous solution of toluenediamine (TDA) which is subjected to a first distillation to obtain water, ammonia and light organic impurities at distillation head, traces of TDA and a mixture mainly comprising the TDA at the distillation base. (F1) is the collected aqueous flow on the distillation head. The aqueous effluent comprises less than 0.5%, preferably 0.07-0.15 wt.% of TOC. R : 1-12C alkyl, 1-12C alkoxy, 1-12C atoms, OH, halo or trihalogenomethyl, preferably 1-4C alkyl, Cl, F or trifluoromethyl; x : 1-3, preferably 1-2; and y : 0-4, preferably 0-2. #CMT#[Image]#/CMT# #CMT#EXAMPLE : #/CMT# The aqueous effluent flow was supplied in bottom of the column having 8 levels under atmospheric pressure and with a flow rate of 75. The flow of aromatic amine (1000 kg/hour) was recycled at 102[deg] C. Then drawing the liquid flow was carried out in the boiler, with the flow of 8080 kg/hour at 101[deg] C. The gas flow (9920 kg/hour) was cooled at 97-55[deg] C, refluxed and then the remaining of the flow (120 kg/hour) was sent to a destruction, in column head. The flow was concentrated in organic compounds to eliminate over 93% of initial pollutants, to give liquid flow of aromatic amine, gas and purified water. |
