METHOD FOR CLEANING 1,4-DIAMINOBUTANE, CLEANED BY THE PROVIDED METHOD OF 1,4-DIAMINOBUTANE AND POLYAMIDE OBTAINED FROM IT Russian patent published in 2017 - IPC C07C209/84 C07C211/09 C12P13/00 C08G69/04 

FIELD: chemistry.

SUBSTANCE: invention relates to an improved process for the purification of 1.4-diaminobutane (putrescine), obtained by fermentation. 1.4-diaminobutane may be used to prepare polyamides. The purification method comprises concentrating the fermentation solution containing at least 1.4-diaminobutane and its salt, to obtain a concentrate. To the concentrate of the fermentation solution, the base is added to give the basic composition, characterized by a pH above 12 and then it is recovered from 1.4-diaminobutane basic composition. At least a portion of the solvent in the fermentation solution is generally removed in the course of concentrating the fermentation solution. Preferably, the concentration of the fermentation solution is performed at a vapor temperature of from 45 to 100°C at a pressure of from 40 to 500 mm Hg. From a fermentation solution, before the step of concentrating the fermentation solution, the step of removing the bacterial cells may be performed. The amount of solvent in the concentrate is in the range of from 15 to 45 wt % based on the total weight of the concentrate. The base is at least one selected from the group consisting of sodium hydroxide, calcium hydroxide, magnesium hydroxide, potassium hydroxide, barium hydroxide and ammonium hydroxide, and the pH of the basic structure is characterized by higher value of 12.0 to 14.0. Extracting the 1.4-diaminobutane from the basic composition comprises separating 1.4-diaminobutane-containing composition from the basic composition by distillation, and recovery of 1.4-diaminobutane from 1.4-diaminobutane-containing composition by means of fractional distillation. These steps may be performed continuously using a distillation column for the fractional distillation step. In doing so, the extracting of 1.4-diaminobutane-containing from the whole part is held when the steam temperature from 40 to 120°C and a pressure of from 70 to 200 mm Hg. Usually 1.4-diaminobutane-containing complex is in a liquid form. The distillation column is operated at a steam temperature from 40 to 120°C and a pressure from 70 to 200 mm Hg, with recovery of 1.4-diaminobutane in the bottom zone of the distillation column.

EFFECT: method allows to increase the recovery rate of diaminobutane and to simplify the process by removing the salt using a nanofiltration membrane.

16 cl, 5 tbl, 2 dwg, 4 ex