Yeast-based biodiesel production using sulfonated carbon-based solid acid catalyst by an integrated biorefinery of durian peel waste

An integrated biorefinery concept for yeast-based biodiesel production using durian peel (DP) as a feedstock was developed. After dilute acid hydrolysis, DP hydrolysate (DPH) and DP solid fraction (DPSF) hydrolysis residues were generated. Yeast lipid was produced from undetoxified DPH by Rhodotorula mucilaginosa KKUSY14. DPSF was subjected to a one-step sulfonation process to prepare a solid catalyst (DPSF-SO3H) and was characterized using FTIR, XRD, and FE-SEM analysis. DPSF-SO3H catalyst exhibited good catalytic activity for yeast-based biodiesel (FAME) production from wet cell of KKUSY14 grown in DPH by direct transesterification. FAME yields of 81.57% and 78.73% were reached, respectively, for microwave and conventional heating. The fuel properties of FAME were in accordance with the ASTM and EN standards. Based on the higher heating value of FAME produced, an energy output of about 32.44-34.90 MJ/kg was estimated. The proposed bio-refinery concept led to the production of 101.2 kg yeast biomass, 16.0 kg yeast lipid, 717 kg DPSF-SO3H catalyst, 79.7-82.6 kg FAME, and 70.4 kg yeast residues from 1000 kg of DP waste. This model clearly provides economic benefits by creating value-added products and eliminating any waste streams. (C) 2021 Elsevier Ltd. All rights reserved.

Automated summary

An integrated biorefinery concept was developed for yeast-based biodiesel production using durian peel as a feedstock. By utilizing different processes, efficient and cost-effective production of yeast lipid and biodiesel from the waste material was achieved, meeting fuel standards.