Purified Glycerine from Biodiesel Production as Biomass or Waste-Based Green Raw Material for the Production of Biochemicals

Glycerine (glycerol) is a polyol consisting of three carbon atoms bonded to hydroxyl groups. It is a by-product of the transesterification of triglycerides, such as animal fats, vegetable oils, or used cooking oils during the biodiesel production process. Crude glycerine is subject to purification processes resulting in distilled glycerine containing at least 99.5% glycerol. Currently, produced high-quality distilled glycerine is used in the food, pharmaceutical, and cosmetic industries. Recently, technologies for converting glycerol to other chemicals through catalytic processes have been intensively developed, e.g., production of bio-based 1,2-propanediol. In the near future, glycerol will certainly become a promising renewable raw material in many modern biorefineries for the synthesis of biofuels, chemicals, and bioenergy production. This paper presents the possibility of using ion exchange resins to remove impurities with trace amounts of sulphur and nitrogen compounds from crude and distilled glycerine, produced during the biodiesel production process from used cooking oils. It was determined that using ion exchange resins at the preliminary purification stage (before distillation) was ineffective. Using cationite resins to purify distilled glycerine produced from waste materials enables the removal of impurities in the form of sulphur and nitrogen compounds.