CN1260409A

CN1260409A - Production technique for L-cysteine hydrochloride monohydrate

Info

Publication number: CN1260409A
Application number: CN 98121643
Authority: CN
Inventors: 牛南钢; 胡志鹏
Original assignee: HUANGSHI CITY SAPONIN PLANT
Current assignee: HUANGSHI CITY SAPONIN PLANT
Priority date: 1998-10-23
Filing date: 1998-10-23
Publication date: 2000-07-19

Abstract

The production process of L-cysteine hydrochloride monohydrate is characterized by firstly making L-cysteine hydrochloride solution undergo the processes of electrolysis, decolouring, filtering, concentrating, crystallizing and separation, then returning the separated mother liquor back into electrolytic cell to make electrolysis, and its quality and yield are obviously raised.

Description

L-cysteine hydrochloride-water thing production technique

The invention belongs to biological chemical field, be specifically related to a kind of can be used for bread fermentation, fresh-keeping, prevent V in the straight juice _COxidation and brown stain, have the L-cysteine hydrochloride monohydrate production technique of treatment bronchitis and resolve phlegm effect.

The L-cysteine hydrochloride monohydrate, its molecular formula is:

Molecular weight: 175.61, can be used as bread fermentation promotor, preservation agent; Quicken the formation of gluten, prevent to wear out; Be used for straight juice and can prevent V _COxidation and brown stain; Fine and aromatic acid is poisoned to propylene detoxification, has prevention radiation injury and treatment bronchitis and resolve phlegm effect.

This product of domestic production mainly adopts following two kinds of methods at present:

(1) adopt high pure metal tin etc. in acidic medium, the L-Gelucystine to be reduced into the L-halfcystine, then through concentrate, process for refining makes;

But because this technological operation is loaded down with trivial details, cost is high, yield is low, so generally be not used at present.

(2) adopting electrolytic reduction, is anode with graphite, makes negative electrode with stereotype, and hydrochloric acid is anolyte, and the hydrochloric acid soln of L-Gelucystine is a catholyte, through electrolysis, decolouring, filtration, concentrate, technology such as crystallization makes.

This technology is for first kind of technology, and easy and simple to handle, cost is low, and the yield height is adopted by most of producer at present.But do not reclaim then very big in this technology as mother liquor to the yield influence, and in the current technology concentrated, crystallization is returned in the recovery employing of mother liquor again, but the quality product of gained is not high like this, especially physical and chemical project such as specific rotation, transmitance does not reach the specification of quality of exported product, and total recovery is also had certain influence.

Purpose of the present invention is exactly by the improvement to mother liquor way of recycling in the above-mentioned technology, has proposed a kind of can stably improving the quality of products and the L-cysteine hydrochloride monohydrate production technique of total recovery.

Technical scheme of the present invention is: with L-cystine salt acid solution, place electrolysis in the electrolyzer, decolouring, filtration, concentrate, crystallization, separation, mother liquor after separating is returned electrolyzer again, adjust suitable electric current and carry out electrolysis, and then decolour, filter, concentrate, technology such as crystallization, resulting quality product meets the requirement under " L-cysteine hydrochloride monohydrate " item in 92 editions standards of Japanese aginomoto, and average yield has improved 5-8%, stably reaches more than 1.375.

Figure is referring to accompanying drawing for its technological process of production.

Following table is the contrast and experiment of the old and new's technology aspect product quality and total recovery.

Old technology:

Lot number	980601	980602	980603	980604	980605	980606
Lot number	980601	980602	980603	980604	980605	980606	Inventory	100KG	100KG	100KG	100KG	100KG	100KG
Transmitance	98.5％	98％	98％	98.5％	97％	98.5％	Inventory	100KG	100KG	100KG	100KG	100KG	100KG
Transmitance	98.5％	98％	98％	98.5％	97％	98.5％	Specific rotatory power [α]_D ²⁰	+5.5°	+5.6°	+5.7°	+5.5°	+5.5°	+5.6°
Total recovery	134.5％	134.0％	135.5％	134.0％	133.9％	133.5％	Specific rotatory power [α]_D ²⁰	+5.5°	+5.6°	+5.7°	+5.5°	+5.5°	+5.6°
Total recovery	134.5％	134.0％	135.5％	134.0％	133.9％	133.5％	Other indexs	All meet 92 editions standards of Japanese aginomoto

New technology:

Lot number	980609	980610	980611	980612	980613	980614
Lot number	980609	980610	980611	980612	980613	980614	Inventory	100KG	100KG	100KG	100KG	100KG	100KG
Transmitance	99％	99.5％	99.5％	99.5％	99％	99.5％	Inventory	100KG	100KG	100KG	100KG	100KG	100KG
Transmitance	99％	99.5％	99.5％	99.5％	99％	99.5％	Specific rotatory power [α]_D ²⁰	+5.9°	+5.8°	+6.0°	+6.2°	+6.3°	+6.2°
Total recovery	137.5％	138.0％	137.7％	138.2％	136.6％	140.7％	Specific rotatory power [α]_D ²⁰	+5.9°	+5.8°	+6.0°	+6.2°	+6.3°	+6.2°
Total recovery	137.5％	138.0％	137.7％	138.2％	136.6％	140.7％	Other indexs	All meet 92 editions standards of Japanese aginomoto

The electrolysis time of above-mentioned mother liquor is decided according to concentration, the specific rotation of mother liquor, and generally speaking, concentration is bigger, and specific rotation is high more, and the required electrolytic time is long more, but generally is good in 2-6 hour.

Be described in further detail embodiments of the invention below again.

Embodiment 1: get 100KG L-Gelucystine in basin, add refining dissolving with hydrochloric acid, the concentration that makes hydrochloric acid is 2-2.5N, and last volume is about 650L.It is squeezed into electrolyzer carry out electrolysis, Faradaic current is 300-375A, and the time is 12-16 hour, and current density is 0.08-0.09A/CM ², add the 3KG activated carbon decolorizing after the electrolysis.Through the plate-and-frame filter press press filtration, specific rotation be+2.5 ° a electrolytic solution, vacuum concentration, crystallization, the whizzer drying, vacuum-drying gets finished product 108KG; Mother liquor under whizzer gets rid of returns electrolyzer and carries out electrolysis, and Faradaic current is 300A, and electrolysis time is 2 hours, reclaim finished product 29.5KG, comprehensive yield is 1.375.

Embodiment 2: charging capacity and electrolysis for the first time, treating processes are with embodiment 1, and difference is that the mother liquor electrolysis time is 6 hours, gained recovery product 50KG.

Embodiment 3: charging capacity and electrolysis for the first time, treating processes are with embodiment 1, and difference is that the mother liquor electrolysis time is 4 hours, gained recovery product 48KG.

Claims

1.L-the cysteine hydrochloride monohydrate production technique is at first carried out electrolysis with L-cystine salt acid solution, control Faradaic current 300-375A, current density 0.08-0.09A/CM ²Electrolysis time 12-16 hour, electrolytic solution through decolouring, filter, concentrate, crystallization, separation, drying gets product; It is characterized in that: the mother liquor after it is separated return again electrolyzer carry out electrolysis, again through decolouring, filter, concentrate, crystallization, separation, promptly get and reclaim finished product.

2. L-cysteine hydrochloride monohydrate production technique according to claim 1 is characterized in that: the electrolysis time of described mother liquor is 2-6 hour.