Process simulation for xylitol production from brewer’s spent grain in a Colombian biorefinery. Part 1: Xylose production from arabinoxilans extracted by the alkaline pretreatment of BSG

Abstract

This work presents the simulation in Aspen Plusr of a process to obtain arabinoxylans (AX) from Brewer’s Spent Grain (BSG), which is the major byproduct of the brewing industry. The process is divided into two stages: alkaline pretreatment and enzymatic hydrolysis. These stages cover the extraction of proteins and AX from BSG using an alkaline pretreatment and enzymatic hydrolysis of the AX separated from the liquid stream to obtain xylose, i.e. the substrate required for the fermentation to xylitol. Simulation results show that xylose obtained corresponds to 8,5% of the dry weight of the raw material, obtaining a yield of 58%. Several streams of byproducts were obtained, such as proteins, polypeptides, amino acids, phenolic compounds and lignocellulosic residues that can be valorized in other processes. Simulation was performed in the context of a biorefinery in Colombia.

Keywords

• simulation
• brewer’s spent grain
• xylitol
• biorefinery