Desalting purifying method in L-carnitine production

Abstract

The invention discloses a desalting purifying method in L-carnitine production, comprising the following steps of: adding an aqueous L-carnitine solution which is synthesized by a chemical method and contains sodium chloride, potassium chloride and ammonium chloride or salt-mixture thereof into a stock solution trough as a stock solution; carrying out cross-flow filtration by intercepting a nanofiltration membrane with the molecular weight of 90-400 under the conditions that inlet pressure is 0.5-5 MPa and outlet pressure is 0.3-4.8 MPa; collecting osmosed liquid and concentrated liquid; returning the concentrated liquid to the stock solution trough, and adding water to the stock solution trough, wherein the added water volume is equal to the volume of the osmosed liquid; circularly carrying out the cross-flow filtration under the same condition; when the conductivity of the solution inside the stock solution trough is less than 1000 microseconds / centimeter, stopping the cross-flow filtration; and concentrating and crystallizing the solution with the conductivity of less than 1000 microseconds / centimeter to obtain the L-carnitine. The invention has moderate condition, short process flow, simple step without environmental pollution; and in addition, purified water obtained through the reverse osmosis treatment of the osmosed liquid finally generated in the production process can also be circularly utilized.

Description

technical field [0001] The invention belongs to the field of chemistry and chemical engineering, and relates to a desalination and purification method in the production of L-carnitine. Background technique [0002] The physiological function of L-carnitine is mainly to promote the β-oxidation of fatty acids, and the fatty acylcarnitine it forms transports long-chain fatty acids from the outside of the mitochondrial membrane to the inside of the membrane. Fat is metabolized and converted into energy in the mitochondria. It can also transport the short-chain acyl group in the mitochondria to the outside of the membrane, and play a role in regulating the ratio of acyl CoA / CoA in the mitochondria, which is beneficial to energy metabolism. In addition, it also participates in the transportation and excretion of other acyl groups to avoid the metabolic toxicity caused by the accumulation of acyl groups in the body, or it is beneficial to the normal metabolism of some branched-cha...

AI Technical Summary

Problems solved by technology

[0003] At present, the mature L-carnitine synthesis methods mainly include microbial fermentation and chemical synthesis, wherein the chemical synthesis is divided into split method and asymmetric synthesis method, and the desalination and purification methods of L-carnitine in these methods are mainly Based on the ion resin adsorption method, such as US6566552, EP-B-295109, WO2007139238, but in the ion resin adsorption method, a large amount of ammonia water is needed for eluting L-carnitine, and a large amount of hydrochloric acid is used for the regeneration of the resin, containing Nitrogen wastewater is difficult to treat, which will cause great pressure on environmental protection and is not environmentally friendly

In CN101274899, electrodialysis is used for desalination and purification, but electrodialysis is prone to produce concentration difference polarization, and further has an extremely adverse effect on the electrodialysis process. The polarization of concentration makes the aqueous solution ionized to generate hydrogen and chlorine, causing potential safety hazards. It will cause changes in the pH value of the solution, which will corrode the ionic membrane and affect its service life

At the same time, electrodialysis consumes a lot of electric energy due to electrolysis