CN109836347A - A kind of l-Isoleucine crystallization preparation process - Google Patents

Abstract

The invention discloses a kind of l-Isoleucine to crystallize preparation process, steps are as follows: l-Isoleucine being added in purified water under room temperature, is stirred evenly, nitrous acid is added, l-Isoleucine and the molar ratio of nitrous acid are 1: 1-1.1, and the weight ratio of l-Isoleucine and water is 1: 0.4；Reaction temperature at 40 DEG C~70 DEG C, gradually clarify by solution, and adjusting pH value of solution with nitrous acid is 1~2；10 DEG C~25 DEG C are cooled to after solution clarification, the crystallization of precipitation is separated by solid-liquid separation；Liquid after 60 DEG C~85 DEG C dry l-Isoleucine nitrite finished products, separation of solid and liquid is that mother liquor continues cycling through use after crystal rinses.A kind of l-Isoleucine of the present invention crystallizes preparation process, is reacted under normal pressure using the l-Isoleucine of food-grade with the nitrous acid of chemical reagent-grade, and reaction condition is mild, and rational technology is easy, and good product quality purity is 99% or more.And the mother liquor after crystallizing in production can continue cycling through use, and high income reaches 98% or more, is suitble to industrialized production.

Description

A kind of l-Isoleucine crystallization preparation process

Technical field

The invention belongs to a kind of good product quality, high income, l-Isoleucine at low cost to crystallize preparation process.

Background technique

Isoleucine, scientific name 2- amino -3 methylvaleric acid, alias isoleucine are wherein the one of 20 kinds of primary amino acids Kind, almost it is present in the structure of all proteins.Isoleucine has 2 asymmetric carbon atoms, thus its there are 4 kinds of alloisomerisms The diastereomer of body and 2 l-Isoleucine, but one seed type of l-Isoleucine is only existed in nature.Due to the different bright ammonia of L- Acid cannot synthesize in human body, so it is essential amino acid, be referred to as branched-amino with L-Leu, Valine Acid plays a significant role in human life metabolism because of its special structure and function.

In the world, mainly there are Japanese aginomoto, consonance fermentation, the pharmacy of field side and Germany in l-Isoleucine manufacturer 4 company such as Degussa is all made of Fermentation production l-Isoleucine.Wherein, Japan is in l-Isoleucine yield, product It occupies first place in the world in matter and science and technology, l-Isoleucine acid production rate is 35-50g/L, and recovery rate is 70%.At home, raw Producing producer mainly has Hubei Yi Yao group company, Yichang Three Gorges pharmaceutcal corporation, Ltd, Wuxi Jing Hai amino acid company, Nanning peace power Safe medicine company Co., Ltd etc..It is domestic simultaneously l-Isoleucine is extracted to ion exchange adsorption also to have many reports and specially Benefit utilizes ion for example, coming rosy clouds and Qinghua LIU and reporting on Shenyang Pharmaceutical University's journal, Wuxi Light Industry Univ.'s journal respectively The technique of exchange process extraction l-Isoleucine；Chinese patent CN200510123082.X discloses ion-exchange from fermentation liquid Extract the process for cleanly preparing of l-Isoleucine.But the recovery rate of the l-Isoleucine in these reports only has 50~60%, And quality is relatively low.

Summary of the invention

The present invention is to solve the problems, such as l-Isoleucine large-scale production and providing one kind industrialized production and can receive Rate is high, and product purity is high, and a kind of l-Isoleucine at low cost crystallizes preparation process.

The technical solution used in the present invention is: a kind of l-Isoleucine crystallizes preparation process: 1. under room temperature that L- is different bright Propylhomoserin is added in purified water, is stirred evenly, and adds nitrous acid, and the molar ratio of l-Isoleucine and nitrous acid is 1: 1~ 1.1, the weight ratio of l-Isoleucine and purified water is 1: 0.4；Reaction temperature at 40 DEG C~70 DEG C, gradually clarify by solution, with Asia It is 1~2 that nitric acid, which adjusts pH value of solution,；10 DEG C~25 DEG C are cooled to after solution clarification, the crystallization of precipitation is separated by solid-liquid separation；Crystallization Liquid after 60 DEG C~85 DEG C dry l-Isoleucine nitrite finished products, separation of solid and liquid is that mother liquor continues to follow after object rinses Ring uses；2. stirring evenly in the mother liquor for 1. generating l-Isoleucine addition step under room temperature, adding nitrous acid, L- is different The molar ratio of leucine and nitrous acid is 1: 1, and the weight ratio of l-Isoleucine and mother liquor is 1: 0.4；Reaction temperature 40 DEG C~ 70 DEG C, solution is gradually clarified, and adjusting pH value of solution with nitrous acid is 1~2, is cooled to 10 DEG C~25 DEG C after solution clarification, will be precipitated Crystallization be separated by solid-liquid separation；Crystal rinse after in 60 DEG C~85 DEG C dry l-Isoleucine nitrite finished products, separation Liquid afterwards is that mother liquor continues to be repeatedly circulated.

The preparation method is that: 1. l-Isoleucine is added in purified water under room temperature, stirs evenly, adds Asia Nitric acid；L-Isoleucine and the molar ratio of nitrous acid are 1: 1, and the weight ratio of l-Isoleucine and purified water is 1: 0.4；Reaction temperature Degree at 55 DEG C ± 5 DEG C, gradually clarify by solution, and adjusting pH value of solution with nitrous acid is 1~2, is cooled to 20 DEG C ± 2 after solution clarification DEG C, the crystallization of precipitation is separated by solid-liquid separation；Crystal rinse after in 80 DEG C of dry l-Isoleucine nitrite finished products；Gu Liquid after liquid separation is that mother liquor continues cycling through use；2. l-Isoleucine is added in mother liquor under room temperature, stir evenly, then plus Enter nitrous acid, the molar ratio of l-Isoleucine and nitrous acid is 1: 1, and the weight ratio of l-Isoleucine and mother liquor is 1: 0.4；Reaction Temperature at 55 DEG C ± 5 DEG C, gradually clarify by solution, and adjusting pH value of solution with nitrous acid is 2, is cooled to 20 DEG C ± 2 DEG C after solution clarification, The crystallization of precipitation is separated by solid-liquid separation；Crystal rinse after in 80 DEG C of dry l-Isoleucine nitrite finished products, separation Liquid afterwards is that mother liquor continues to be repeatedly circulated.

The advantages and positive effects of the present invention are: the present invention is anti-under normal pressure using l-Isoleucine and nitrous acid It answers, reaction condition is mild.The raw material that the present invention uses are the l-Isoleucine of food-grade and the nitrous acid of chemical reagent-grade, institute With the good product quality produced, just reaches 99% or more without recrystallizing purity, not only ensure that quality, but also save work Sequence improves production efficiency.The present invention utilizes the Recycling Mother Solution generated when first production to use, and improves yield, receives product Rate reaches 98% or more, reduces costs.Preparation method of the invention rationally, simply, is suitble to industrialized production.

Specific embodiment

Embodiment 1

Double centner l-Isoleucine is added in 40 kilograms of purified waters at room temperature, is stirred evenly, then be added while stirring 81 kilogram 68% of nitrous acid is gradually heated to 55 DEG C ± 5 DEG C after adding nitrous acid.It is gradually clarified as temperature increases solution, PH is detected before reaction terminates, is 2 with the pH of nitrous acid-conditioning solution.Solution is cooled to 20 DEG C of generation knots immediately after clarifying completely Crystalline substance separates crystal and mother liquor with centrifugal method, and crystal drying rinses knot with the dehydrated alcohol of crystal weight 10~20% Brilliant object, drying, up to l-Isoleucine nitrite finished product, yield 30% after 80 DEG C of dryings.Post mother liquor is centrifugated to continue instead It is multiple to be recycled.

Embodiment 2

Double centner l-Isoleucine is added in about 40 kilograms of mother liquors that embodiment 1 generates, is stirred evenly at room temperature, The nitrous acid for adding 81 kilogram 68% is gradually heated to 45 DEG C ± 5 DEG C after adding nitrous acid.As temperature increases, solution by Step clarification, detects pH before reaction terminates, and is 2 with the pH of nitrous acid-conditioning solution.Solution is cooled to 15 after clarifying completely immediately DEG C crystallization is generated, separates crystal and mother liquor, crystal drying, with the anhydrous second of crystal weight 10~20% with centrifugal method Alcohol rinses crystal, drying, up to l-Isoleucine nitrite finished product, yield nearly 100% after 80 DEG C of dryings.Mother liquor continues anti- It is multiple to be recycled.

Claims (1)

1. a kind of l-Isoleucine crystallizes preparation process, it is characterised in that: l-Isoleucine is 1. added to purified water under room temperature In, it stirs evenly, adds nitrous acid, the molar ratio of l-Isoleucine and nitrous acid is 1: 1~1.1, l-Isoleucine and water Weight ratio be 1: 0.4；Reaction temperature at 40 DEG C~70 DEG C, gradually clarify by solution, is 1~2 with nitrous acid adjustment pH value of solution；It is molten 10 DEG C~25 DEG C are cooled to after liquid clarification, the crystallization of precipitation is separated by solid-liquid separation；Crystal is dry in 60 DEG C~85 DEG C after rinsing Dry to obtain l-Isoleucine nitrite finished product, the liquid after separation of solid and liquid is that mother liquor continues cycling through use；2. under room temperature that L- is different Leucine is added in 1. mother liquor that step generates, stirs evenly, adds nitrous acid, the molar ratio of l-Isoleucine and nitrous acid It is 1: 1~1.1, the weight ratio of l-Isoleucine and mother liquor is 1: 0.4；Reaction temperature at 40 DEG C~70 DEG C, gradually clarify by solution, It is 1~2 with nitrous acid adjustment pH value of solution, is cooled to 10 DEG C~25 DEG C after solution clarification, the crystallization of precipitation is separated by solid-liquid separation； Crystal is dry that l-Isoleucine nitrite finished product, the liquid after separation are that mother liquor continues instead in 60 DEG C~85 DEG C after rinsing It is multiple to be recycled.