Sustainable biological production and innovative purification of the 1,3-propanediol from glycerol fermentation broth via resin adsorption

The study focuses on enhancing the production and purification of 1,3-Propanediol (1,3-PDO), a versatile compound used across various industries. Conventionally, 1,3-propanediol (1,3-PDO) has been derived from petroleum-based feedstocks through chemical processes, which pose significant cost and environmental concerns. This has prompted the exploration of sustainable biological production methods using microorganisms to ferment glycerol, the main by-product of palm oil transesterification in biodiesel production. However, downstream purification remains complex and inefficient. To address this, our study introduces a novel and economically viable purification strategy for 1,3-PDO derived from a semi-industrial fermentation broth. The purification process involves pre-treatment steps: centrifugation, flocculation with chitosan, decolorization with activated charcoal, and broth concentration via rotary evaporation. These steps resulted in a transparent broth with a minimal 6 % loss of 1,3-PDO. Various resin types, including Sulfonated Styrene Divinylbenzene (S-SDVB) and Styrene Divinylbenzene (SDVB) ion exchange resins in different ionic forms in addition to silica gel resin, were evaluated for their effectiveness in separating 1,3-PDO in terms of recovery and purity. A key aspect of our study is the detailed investigation of the equilibrium adsorption characteristics of SDVB and S-SDVB resins, each with different ion forms. This analysis provides insights into how resin modifications affect the separation process, aiming for higher yields and purities of 1,3-PDO. The findings revealed that the Langmuir adsorption isotherm fits experimental data. Column chromatography experiments showed SDVB resins' deficiencies in separating 1,3-PDO from other components, while silica gel resin achieved a recovery rate exceeding 96 % purity and approximately 80 % overall recovery. Notably, the Ca²⁺ form of S-SDVB resin achieved high recovery (95–100 %) and purity (91–93 %) in both synthetic and real fermentation broths, addressing biodiesel challenges and proposing a solution for large-scale microbial 1,3-PDO production.