Separation, purification, and crystallization of 1,5-pentanediamine hydrochloride from fermentation broth by cation resin

Abstract

1,5-Pentanediamine hydrochloride (PDAH) was an important raw material for the preparation of bio-based pentamethylene diisocyanate (PDI). PDI has shown excellent properties in the application of adhesives and thermosetting polyurethane. In this study, PDAH was recovered from 1,5-pentanediamine (PDA) fermentation broth using a cation exchange resin and purified by crystallization. D152 was selected as the most suitable resin for purifying PDAH. The effects of solution pH, initial temperature, concentration of PDA, and adsorption time were studied by the static adsorption method. The equilibrium adsorption data were well fitted to Langmiur, Freundlich, and Temkin-Pyzhev adsorption isotherms. The adsorption free energy, enthalpy, and entropy were calculated. The experimental data were well described by the pseudo first-order kinetics model. The dynamic experiment in the fixed bed column showed that under optimal conditions, the adsorption capacity reached 96.45 mg g−1, and the recovery proportion of the effective section reached 80.16%. In addition, the crystallization of the PDAH solution obtained by elution proved that the crystal product quality of resin eluting solution was highest. Thus, our research will contribute to the industrial scale-up of the separation of PDAH.

Thermodynamics, Solubility, and Crystallization of 1,5-Pentylenediamine Hydrochloride in Mixed Solvent Systems

“…These peaks belong to the same crystal form. It can be seen that the cooling crystallization has more impurities . Based on differences in the solubility of impurities and products, the purity of the crystal can be further improved by antisolvent crystallization.…”

“…Cooling crystallization was conducted by adding the 750 g·L –1 PDAH solution (10 mL) to a 200 mL jacketed beaker, heated to 50 °C, and then cooled from 20 to −10 °C. The crystals were allowed to grow for 1 h, after which suction filtration, washing, and drying were performed to obtain PDAH …”

“…8 Preparing good quality 1,5pentylenediamine hydrochloride (PDAH), a solid salt of PDA, can effectively reduce the occurrence of side reactions during phosgenation and ultimately improve the yield and purity of PDI. 9 Crystallization separation is a key step in the production process for removing impurities and controlling the product quality. Common crystallization methods include reaction, antisolvent, 10 cooling, 11 evaporation, and melt crystallization.…”

“…However, side reactions inevitably occur during phosgenation . Preparing good quality 1,5-pentylenediamine hydrochloride (PDAH), a solid salt of PDA, can effectively reduce the occurrence of side reactions during phosgenation and ultimately improve the yield and purity of PDI …”

“…In addition, the relationship between solubility and temperature can be analyzed thermodynamically, providing key information on the molecular mechanisms and solvent–solute molecular interactions involved in dissolution . Our group previously investigated a pathway for obtaining a high-purity PDAH solution from biotransformation fluids, and here, we continue to investigate the crystallization of high-quality PDAH. The PDAH dissolution data were analyzed by correlation fitting with the modified Apelblat, λ h , polynomial empirical, and the modified van’t Hoff–Jouyban–Acree equation.…”