CN106349300A - Method for reaction of sucralose esterified single solvent - Google Patents

Abstract

The invention relates to a method for the reaction of sucralose esterified single solvent, characterized by: 1) DMF, sucrose and organotin acetate are subjected to negative pressure esterification in an esterification kettle while DMF is recovered to the bypass channels of earlier stage by negative pressure distillation and condensing, and the recovered DMF whose water content is larger than 0.9-1.0% ppm is to be delivered into the recovery system; 2) Negative pressure recovery of DMF continues until the water content is less than 0.6% ppm, then which is returned to the esterification kettle for the next batch of esterification reaction; 3) The esterification reaction material is added into the esterification kettle, and acetic anhydride is added dropwisely in; water is added after adding dropwisely, and sucrose 6 ester and organotin acetate are extracted and separated with cyclohexane; organic tin acetate present in the cyclohexane phase, which is produced through evaporating of the cyclohexane solvent. The advantages of the method for the reaction of sucralose esterified single solvent is shortening the production cycle, eliminating the original tin recovery process, reducing the consumption of raw materials and energy and maximizing the savings in all costs.

Description

The single solvent reaction method of sucralose esterification

Technical field

The present invention relates to food additive production field, specifically a kind of sucralose esterification list solvent reaction method.

Background technology

As shown in figure 1, during existing sucralose produces, as first step esterification by the use of dmf and hexamethylene as Solvent and the conventional dehydration reaction method adding catalyst organotin, are extracted with hexamethylene after the completion of reaction, extract anti- Answer the organotin acetass in liquid, hexamethylene is reclaimed in then air-distillation, remaining pulpous state organotin acetass methanol dissolves, so After be added drop-wise in sodium hydroxide solution and be neutralized, after neutralization, organotin produces in solid form, reuse after filtration washing, so Substantial amounts of washess can be produced and recovery dmf, hexamethylene, methanol will consume a certain amount of steam and solvent.

Content of the invention

The purpose of the present invention is exactly in order to solve complex process in prior art, solvent recovery consumes energy high, heavy-polluted lacking Fall into, provide a kind of sucralose esterification single solvent reaction method, shorten the production cycle, save former organotin recycling, reduce Raw material, the consumption of energy greatly improve the yield rate of product.

The technical solution adopted for the present invention to solve the technical problems is:

A kind of sucralose esterification list solvent reaction method, solvent dmf is added in reaction kettle of the esterification, adds sucrose, heating afterwards To 84～86 DEG C carry out early stage molten sugar it is characterised in that:

1), opening vacuum pump makes system produce negative pressure -0.098mpa～-0.01mpa, squeezes into organotin acetic acid toward in esterifying kettle Ester, controls 68～70 DEG C of temperature, carries out negative pressure esterification, the vacuum distillation of fresh water (FW) containing dmf that reaction generates in esterifying kettle And this fresh water (FW) is reclaimed to early stage bypass channel by condenser, in the fresh water (FW) that early stage bypass channel reclaims dmf water content be 0.9～ 1.0%ppm, squeezes into recovery system, separately adds raw material dmf and enters esterifying kettle；

2), after, in the fresh water (FW) that detection is reclaimed, dmf water content is less than 0.67%ppm, the fresh water (FW) containing dmf that negative pressure is reclaimed enters Later stage bypass channel, terminates to obtain organotin condensation substance to reaction, and the fresh water (FW) containing dmf that later stage bypass channel reclaims returns in esterifying kettle and covers With lower batch of esterification；

3), esterification material is squeezed in acylation kettle, kettle temperature is down to temperature control during -1.5 DEG C of beginning Deca acetic anhydrides, Deca System, at -2～2 DEG C, adds water and uses hexamethylene extract and separate to generate sucrose 6 ester and organotin acetass, organotin after being added dropwise to complete Acetass are present in hexamethylene phase, and then evaporation solvent hexamethylene obtains organotin acetass.

Technical scheme, makes organotin ester recycle, original reactor is changed by whole course of reaction by normal pressure For negative pressure equipment, increase vacuum pump set, reaction after making reaction mass boiling take the water of technological reaction generation out of under negative pressure generates institute Obtain product.

The invention has the beneficial effects as follows, shorten the production cycle, save the recycling of former organotin, reduce raw material and energy Consume, save every cost consumption to greatest extent.

Brief description

The present invention is further described with reference to the accompanying drawings and examples:

Fig. 1 is existing sucralose esterification reacting flow chart；

Fig. 2 is the sucralose esterification reacting flow chart of the present invention.

Specific embodiment

As shown in Fig. 2 accurately put the dmf 700l and dmf1200l of upper batch recovery jointly entering in esterifying kettle, and throw in Sucrose 300kg enters in esterifying kettle, heat temperature raising, and Steam pressure control closes steam in 1.8～2.0mpa when temperature rises to 70 DEG C Valve, allows it warm naturally to 84～86 DEG C and is stirred 1.5 hours being fully dissolved sugar.

Open vacuum pump band negative pressure of vacuum to control in the state of -0.085～-0.09mpa, squeeze into organic toward in esterifying kettle Stannum acetass 600kg, pan feeding opens steam intensification pressure in 0.04～0.05mpa after terminating, be controlled kettle temperature at 68～70 DEG C, Under conditions of negative pressure -0.098mpa～-0.01mpa, normally at 76～78 DEG C, continuation band negative pressure is cooled to kettle temperature and is down to kettle temperature When 68～70 DEG C (period will be observed to show on trial out and be evaporated situation), open steam valve steam pressure and be controlled kettle in 0.08～1.0mpa Temperature at 64～66 DEG C, under conditions of esterifying kettle negative pressure -0.098～-0.01mpa pass through condenser condensation recovery aqueous dmf enter before Phase divides in water storage tank, and in early stage esterifying kettle, reaction is very unstable, notes observing situation in kettle, prevents bumping slug.

Reclaim band water dmf700l about 1 hour under conditions of 64～68 DEG C of negative pressure -0.098mpa kettle temperature, the sampling survey time receives Dmf moisture content, in 0.9～1.0%ppm, then adds 800l raw material dmf toward in esterifying kettle, continues in negative pressure -0.098mpa kettle temperature 64～68 DEG C of condition reclaims aqueous dmf800l(in kettle and amounts to 1500l) about 1 hour, the sampling survey time receives dmf water content After 0.67%ppm, switching is reclaimed aqueous dmf valve and is entered the later stage and divides in water storage tank, continues to add 800l raw material toward in esterifying kettle Dmf, reclaims dmf under conditions of continuing negative pressure -0.098～-0.01mpa, and total recovery volume reaches stopping reacting by heating during 2100l Remove negative pressure, reclaim reaction and terminate to obtain organotin condensation substance.Sampling survey finally go out to carry the final water content of water dmf 0.25% with Under, whole recovered under reduced pressure takes 2.5～3 hours.

(2) open transfer kettle r1103 pan feeding valve to put into esterification material, carry out pre- cooling and process to 35 DEG C, pass through Dnockout pump b1104 pumps in acylation kettle r1104, and kettle temperature is down to -1.5 DEG C and is started Deca acetic acid by acetic anhydride head tank v1108 Acid anhydride, Deca need slowly at the uniform velocity Deca, Deca during temperature control at -2～2 DEG C, uniform Deca takes 1.5 hours, after -2 Under conditions of～2 DEG C continue reaction terminate within 2 hours, by heat exchanger e1105 to material heat cycles to after 30 DEG C blowing arrive extract Take in kettle r1105 stirring, added water 90l by water measuring tank v1110, add hexamethylene 900l from hexamethylene head tank v1109 After stirring 30 minutes, stratification extract and separate goes out sucrose 6 ester and enters v1113 and organotin acetass for heavy phase is light phase In v1112abc, organotin acetass are mainly dissolved in hexamethylene and are totally separated out with hexamethylene extracting and demixing by 3 times, so Afterwards organotin acetass are obtained by normal heating evaporation solvent hexamethylene.

Control steam and recirculated water in whole process it is ensured that reaction temperature, make course of reaction steadily, reaction more abundant, disappear Except anthropic factor, improve the yield rate of product.

The above, be only presently preferred embodiments of the present invention, and not the present invention is made with any pro forma restriction；Appoint What those of ordinary skill in the art, without departing under technical solution of the present invention ambit, can be utilized the side of the disclosure above Method and technology contents make many possible variations and modification to technical solution of the present invention, or the equivalent reality being revised as equivalent variations Apply example.Therefore, every content without departing from technical solution of the present invention, the technical spirit according to the present invention is done to above example Any simple modification, equivalent, equivalence changes and modification, all still fall within the range of technical solution of the present invention protection.

As shown in table 1, esterifying liquid analytical data after the esterification list solvent reaction that the present invention provides

Specifically, using the average normalizing content of solvent pairs old technique saccharose diester 13.56%, appearance content, in 29g/l, is put down The normalizing content of equal sucrose 6 ethyl esters 77%, external standard content 164.6g/l, the average normalizing content of miscellaneous monoesters 7.53%, appearance In 16.6g/l, 9.29%, appearance content is in 18.5g/l, sucrose 6 ethyl ester for new technology saccharose diester average normalizing content for content Average normalizing content 88.4%, appearance content 166.6g/l, no miscellaneous monoesters produces, and the old technique of end reaction yield is 78% 92%, new technology saccharose diester content reduces the reaction yield of new technology, and no miscellaneous monoesters (by-product) composition exists, and effectively becomes Sucrose 6 ethyl ester content is divided to increase, relative purity is higher, and whole reaction yield at least increases by 10 percentage points than old technique.

Claims (1)

1. the single solvent reaction method of sucralose esterification, solvent dmf is added in reaction kettle of the esterification, adds sucrose afterwards, be heated to 84～86 DEG C carry out early stage molten sugar it is characterised in that:

1), opening vacuum pump makes system produce negative pressure -0.098mpa～-0.01mpa, squeezes into organotin acetic acid toward in esterifying kettle Ester, controls 68～70 DEG C of temperature, carries out negative pressure esterification, the vacuum distillation of fresh water (FW) containing dmf that reaction generates in esterifying kettle And this fresh water (FW) is reclaimed to early stage bypass channel by condenser, in the fresh water (FW) that early stage bypass channel reclaims dmf water content be 0.9～ 1.0%ppm, squeezes into recovery system, separately adds raw material dmf and enters esterifying kettle；

2), after, in the fresh water (FW) that detection is reclaimed, dmf water content is less than 0.67%ppm, the fresh water (FW) containing dmf that negative pressure is reclaimed enters Later stage bypass channel, terminates to obtain organotin condensation substance to reaction, and the fresh water (FW) containing dmf that later stage bypass channel reclaims returns in esterifying kettle and covers With lower batch of esterification；

3), esterification material is squeezed in acylation kettle, kettle temperature is down to temperature control during -1.5 DEG C of beginning Deca acetic anhydrides, Deca System, at -2～2 DEG C, adds water and uses hexamethylene extract and separate to generate sucrose 6 ester and organotin acetass, organotin after being added dropwise to complete Acetass are present in hexamethylene phase, and then evaporation solvent hexamethylene obtains organotin acetass.