CN108299522A - A kind of extracting process of trichloro-cane-6-ethyl ester - Google Patents

Abstract

The present invention relates to a kind of extracting process of 6 ethyl ester of Sucralose, include the following steps：A. the dense dry liquid that chlorination reaction is obtained and dimethyl carbonate by volume 1:1.5 are added in extraction kettle, and fully cycle is sent into layering slot and stands 1.5 hours；B. an organic phase of layering is sent into decoloration kettle decoloration, destainer, which is sent into, is concentrated under reduced pressure kettle, recycles extractant dimethyl carbonate DMC, is then crystallized to concentrate, press filtration, obtains 6 ethyl ester of Sucralose；C. by water phase and the dimethyl carbonate after layering by volume 1:1.5, which are added to extraction kettle, carries out reextraction, is then fed into layering slot standing and is layered for 1.5 hours；D. the secondary water phase of layering is sent into tower reactor and carries out air-distillation, recycle molten dimethyl carbonate in water.The present invention selects extractant DMC extraction efficiencies high, reduces volatilization consumption, while the price of DMC is about the half of ethyl acetate price, has greatly saved the energy, reduces cost, increases benefit.

Description

A kind of extracting process of trichloro-cane-6-ethyl ester

Technical field

The invention belongs to food additives production fields, are related to a kind of Sucralose production technology, and in particular to a kind of trichlorine The extracting process of sucrose-6-ethyl ester.

Background technology

Sucralose is a kind of white powder product, is highly soluble in water (solubility 28.2g, 20 °C), sugariness is sucrose 600 times, and sweet taste is pure.Sucralose category non-nutritive intense sweetener, is hardly absorbed, calorie value is in human body Zero.Sucralose property is stablized, and Sucralose replacement sucrose is widely used in many product such as beverage, chewing gum, chocolate at present It is one of comparatively ideal intense sweetener in the market in kind.

Sucralose industrially is produced frequently with monoesters method, it, need to be to anti-after chlorination reaction in Sucralose production The intermediate trichloro-cane-6-ethyl ester that should be generated carries out purification by liquid extraction, to generate purity higher three in follow-up alcoholysis reaction Chlorine sucrose.The extractant selected at present is mostly ethyl acetate, but because of its low boiling point and the characteristics such as volatile, consumption of organic solvent Greatly, production cost has been correspondingly improved, while also polluted environment.It is called for active response national energy conservation and emission reduction, reduces production Cost solves the consumption of extractant widely, to the maximum extent, reduces discharge, energy saving, reduces cost, increases benefit, Trichloro-cane-6-ethyl ester extracting and purifying technology is improved very urgent with innovation.

Invention content

The purpose of the present invention is to solve defects in the prior art, provide a kind of extraction of trichloro-cane-6-ethyl ester Take method.

To achieve the goals above, the technology used in the present invention side is as follows：

A kind of extracting process of trichloro-cane-6-ethyl ester, including existing extraction step：Dense dry liquid extraction, dense dry liquid layering, one Secondary water phase extraction, a water phase layering, secondary water phase recycling catalyst, an ester mutually decolourizes, an ester mutually concentrates, an ester phase Crystallization, an ester phase press filtration；It is characterized in that：

A. the dense dry liquid and dimethyl carbonate chlorination reaction obtained（DMC）Extractant is about 1 according to volume ratio:1.5 ratio It is added in extraction kettle, abundant circulation stirring is sent into layering slot and stands 1.5 hours after 1 hour；

B. the organic phase in ester phase slot layering got is sent into decoloration kettle and carries out activated carbon decolorizing, and control temperature is at 55 DEG C ~60 DEG C, stirring filters out activated carbon after 1 hour, will filter out the destainer after activated carbon and is sent into kettle is concentrated under reduced pressure, control concentration temperature ≤ 45 DEG C of degree recycles extractant dimethyl carbonate DMC, concentrate is then sent into crystallization kettle, filter press successively, concentrate is through knot Trichloro-cane-6-ethyl ester crude product is obtained after brilliant press filtration；

C. by a water phase in got after layering water phase slot with an ester mutually be concentrated to give come dimethyl carbonate DMC by Volume ratio is about 1:1.5 ratio is added to the abundant circulation stirring of extraction kettle and carries out reextraction, and stirring is sent into layering after 1 hour Slot stands 1.5 hours and is layered；

D. secondary water phase layering got is sent into tower reactor and carries out air-distillation, recycles molten dimethyl carbonate DMC in water, returns Waste water after receipts is sent outside to sewage plant.

The invention has the advantages that the boiling point of extractant dimethyl carbonate DMC is higher than ethyl acetate, reduces volatilization and disappear Consumption；Extraction efficiency is high, and need to extract originally under equal conditions three times present need to be extracted twice, and shorten the production cycle, subtract The usage quantity for having lacked equipment improves the utilization rate of equipment, has saved labour；The price of dimethyl carbonate DMC is about second The half of acetoacetic ester price, reduces production cost.

Description of the drawings

Fig. 1 is a kind of extraction process flow schematic diagram of trichloro-cane-6-ethyl ester provided by the invention；

Fig. 2 is the extraction process flow schematic diagram that ethyl acetate is used in prior art.

Specific implementation mode

Embodiment 1：

As shown in Figure 1, a kind of extracting process of trichloro-cane-6-ethyl ester, including existing extraction step：Dense dry liquid extracts, is dense dry Liquid layering, a water phase extraction, a water phase layering, secondary water phase recycles catalyst, an ester mutually decolourizes, an ester is mutually dense It contracts, an ester mutually crystallizes, an ester phase press filtration；Specific implementation step is as follows：

1) dense dry liquid 4000L is pumped into extraction kettle, dimethyl carbonate DMC extractants 6000L, abundant circulation stirring 1 hour is added Layering slot standing is sent into afterwards to be layered within 1.5 hours；

2) the lower layer organic phase 6100L being layered in step 1 is sent into an ester phase slot, then mutually send ester of 6100L Enter the kettle that decolourizes, decoloration kettle temperature degree control is added 20Kg activated carbons and decolourizes at 55 DEG C~60 DEG C, and stirring filters out after 1 hour Activated carbon, will filter out the destainer after activated carbon and is sent into kettle is concentrated under reduced pressure, and control concentration kettle thickening temperature≤45 DEG C, vacuum is kept It can stop concentrating, concentrate is put into when concentrating out dimethyl carbonate DMC volume about 4500L in -0.095~-0.09MPa Crystallization kettle is pressed obtained crystal feeding plate and frame type filter-press with -5 DEG C~0 DEG C of shallow cool brine freezing and crystallizing 6 hours Filter obtains trichloro-cane-6-ethyl ester crude product 587Kg；

3) it will be layered the water phase 3900L of upper layer one time that slot is layered in step 1 and is sent into extraction kettle, dimethyl carbonate DMC is added 5900L carries out reextraction to extraction kettle, squeezes into layering slot after 1 hour through abundant circulation stirring and stands 1.5 hours and is layered, Be layered lower layer organic phase 6000L enter secondary ester phase slot, be layered upper strata aqueous phase 3800L enter secondary water phase slot, secondary water Trichloro-cane-6-ethyl ester content 2.1g/L in phase（It is required that≤3g/L）；

4) secondary water phase is pressed into flow 1.8m³/ h is continuously introduced into tower reactor（Waste water takes off DMC）Progress air-distillation, bottom temperature≤ 105 DEG C, liquid level is maintained at 60%~80%, and waste water is sent outside to sewage plant after recycling dimethyl carbonate DMC.

Claims (1)

1. a kind of extracting process of trichloro-cane-6-ethyl ester, including existing extraction step：Dense dry liquid extracts, dense dry liquid is layered, Water phase extraction, a water phase layering, secondary water phase recycling catalyst, an ester mutually decolourizes, an ester mutually concentrates, an ester Mutually crystallization, an ester phase press filtration；Characterized by the following steps：

A. dense dry liquid chlorination reaction obtained is about 1 according to volume ratio with extractant dimethyl carbonate DMC:1.5 ratio adds Enter into extraction kettle, abundant circulation stirring is sent into layering slot and stands 1.5 hours after 1 hour；

B. the organic phase in ester phase slot layering got is sent into decoloration kettle and carries out activated carbon decolorizing, and control temperature is at 55 DEG C ~60 DEG C, stirring filters out activated carbon after 1 hour, will filter out the destainer after activated carbon and is sent into kettle is concentrated under reduced pressure, control concentration temperature ≤ 45 DEG C of degree recycles extractant dimethyl carbonate DMC, is then crystallized to concentrate, press filtration, obtains Sucralose -6- second Ester crude product；

C. by a water phase in got after layering water phase slot with an ester mutually be concentrated to give come dimethyl carbonate DMC by Volume ratio is about 1:1.5 ratio is added to the abundant circulation stirring of extraction kettle and carries out reextraction, and stirring is sent into layering after 1 hour Slot stands 1.5 hours and is layered；

D. secondary water phase layering got is sent into tower reactor and carries out air-distillation, recycles molten dimethyl carbonate DMC in water, returns Waste water after receipts is sent outside to sewage plant.