A Simple Biorefinery Concept to Produce 2G-Lactic Acid from Sugar Beet Pulp (SBP): A High-Value Target Approach to Valorize a Waste Stream

Molecules. 2020 Apr 30;25(9):2113. doi: 10.3390/molecules25092113.

Abstract

Lactic acid is a high-value molecule with a vast number of applications. Its production in the biorefineries model is a possibility for this sector to aggregate value to its production chain. Thus, this investigation presents a biorefinery model based on the traditional sugar beet industry proposing an approach to produce lactic acid from a waste stream. Sugar beet is used to produce sugar and ethanol, and the remaining pulp is sent to animal feed. Using Bacillus coagulans in a continuous fermentation, 2781.01 g of lactic acid was produced from 3916.91 g of sugars from hydrolyzed sugar beet pulp, with a maximum productivity of 18.06 g L-1h-1. Without interfering in the sugar production, ethanol, or lactic acid, it is also possible to produce pectin and phenolic compounds in the biorefinery. The lactic acid produced was purified by a bipolar membrane electrodialysis and the recovery reached 788.80 g/L with 98% w/w purity.

Keywords: biorefinery; bipolar membrane electrodialysis; lactic acid; second-generation; sugar beet pulp.

MeSH terms

  • Beta vulgaris / chemistry*
  • Bioreactors
  • Ethanol
  • Fermentation*
  • Hydrolysis
  • Lactic Acid / biosynthesis*
  • Lactic Acid / chemistry
  • Sucrose
  • Yeasts / metabolism

Substances

  • Lactic Acid
  • Ethanol
  • Sucrose