Ethanol production from acid-pretreated and detoxified tea processing waste and its modeling


Germec M., TURHAN İ.

FUEL, vol.231, pp.101-109, 2018 (SCI-Expanded, Scopus)

  • Publication Type: Article / Article
  • Volume: 231
  • Publication Date: 2018
  • Doi Number: 10.1016/j.fuel.2018.05.070
  • Journal Name: FUEL
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Page Numbers: pp.101-109
  • Keywords: Chemical composition, Inhibitors, Detoxification, Ethanol fermentation, Mathematical modeling, PICHIA-STIPITIS, SACCHAROMYCES-CEREVISIAE, BATCH FERMENTATION, BACTERIAL-GROWTH, CHEMICALS, EXTRACT, YEAST
  • Akdeniz University Affiliated: Yes

Abstract

Lignocellulosic materials are good feedstocks for ethanol production. Mathematical models give information about kinetic-metabolic nature of fermentation. The objectives of this study were to determine the chemical composition of non-detoxified tea processing waste hydrolysate (ND-TPWH) and detoxified tea processing waste hydrolysate (D-TPWH), to generate the ethanol from the D-TPWH, and to model the ethanol fermentation in DTPWH using models including modified Gompertz, re-modified Gompertz, modified logistic, re-modified logistic, modified Richards, re-modified Richards, Stannard, Baranyi, Weibull, and Morgan-Mercer-Flodin. Results indicated that 11.91% of D-glucuronic acid, 7.28% of acetic acid, 98.12% of hydroxymethylfurfural, and 76.88% of phenolics were adsorbed by detoxification process. Ethanol yields by Saccharomyces cerevisiae and Scheffersomyces stipitis (ATCC 58784 and ATCC 58785) were 35.9, 38.98, and 33.87%, respectively. Regarding modeling, depending on the model comparison results including root-mean-square-error, mean-absolute-error, and regression coefficient, the experimental data of ethanol production and sugar consumption were successfully forecasted using Baranyi and Weibull models for S. cerevisiae; using Morgan-Mercer-Flodin model for S. stipitis (ATCC 58784); and using Stannard model for S. stipitis (ATCC 58785), respectively. Consequently, this was the first report on the ethanol production from D-TPWH and its modeling. TPW can be a good feedstock for ethanol production by the xylose-fermenting yeasts. Suitable flexible models could be applied for more progress of ethanol production process in D-TPWH.