MATHEMATICAL MODELING OF XYLITOL FERMENTATION PROCESS IN REPEATED BATCH OPERATION

• Main Author: Khotibul Ilman, Fathoni
• Format: Final Project
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/67294
• Institution: Institut Teknologi Bandung

OPEFB waste is an abundant biomass in Indonesia that can be utilized through hydrolysis and catalytic hydrogenation to produce xylitol, a sugar with a large and growing market. Meanwhile, the alternative bioprocess pathway through fermentation offers attractive advantages over the chemical pathway because it has a smaller energy input, does not need an ultrapure D-xylose feed, and works in ambient operating conditions. The aim of this research is to model, simulate, and determine the optimum conditions of the xylitol fermentation system with repeated batch operation mode. The modeling was carried out on a submerged fermentation system using a synthetic medium, a glucose-xylose co-substrate system, and Debaryomyces hansenii biocatalyst. The research was conducted in 3 main stages, namely 1) database selection, 2) selection and development of mathematical models, and 3) simulation. The research was conducted with the help of Microsoft Excel and MATLAB software. The duration per cycle is set at 48 hours, while the number of cycles is set at 6 cycles. The basis data that was used in this study was sourced from the research of Mateo et al. (2021). After performing validation based on data, the suitable kinetic model for this fermentation modeling is the Monod Luedeking-Piret (MLP) kinetic model with kinetic parameters ????????????????????????????????,???????? of 0.362 h-1, ????????????????/???????? of 0.255 gX/gG, ????????????????,???????? of 4.626 g/L, ????????????????????????????????,???????? of 0.011 h-1, ????????????????/???????? of 0.053 gX/gS, ????????????????,???????? of 0.782 g/L, ???????? of 1.139 gP/gX, ???????? of 0.001 gP/gX/h, and ???????????????? of 0.003 h-1. Optimum conditions were obtained with the initial values of glucose 30 g/L, xylose 150 g/L, cells 0.05 g/L, and retention volume ratio of 50% for constant starting concentration scenario. This scenario offers higher volumetric and specific productivity than the most optimum variation for constant volume scenario. This variation gives a productivity increase on the subsequent batch cycles, with a volumetric productivity in g/L/h for cycle 1 until 6 of 0.069, 0.223, 0,294, 0.320, 0.328, and 0.330; as well as a specific productivity in g/g/h for cycle 1 until 6 of 0.001, 0.002, 0.002, 0.001, 0.001, and 0.001, respectively.