Optimization and techno-economic assessment of high-solid fed-batch saccharification and ethanol fermentation by Scheffersomyces stipitis and Saccharomyces cerevisiae consortium

Published Date
December 2016, Vol.99:1062–1072, doi:10.1016/j.renene.2016.08.019

Author 

• Pornkamol Unrean ^,
• Sutamat Khajeeram

• National Center for Genetic Engineering and Biotechnology (BIOTEC), National Science and Technology Development Agency (NSTDA), 113 Thailand Science Park Phahonyothin Road, Klong Nueng, Klong Luang, Pathum Thani, 12120, Thailand

Received 19 January 2016. Revised 21 July 2016. Accepted 5 August 2016. Available online 10 August 2016.

Highlights

• Technological and economical potentials of lignocellulosic bioprocess using yeast consortium were assessed.
• •
  The optimized fed-batch with yeast consortium reached high ethanol titer of 60 g/L and yield exceeding 70% of theoretical.
• •
  The study proved an economically viable prototype of yeast consortium for highly efficient lignocellulosic bioprocess.

Abstract 

In the present work, technological and economical potentials of sugarcane bagasse-to-ethanol process using Scheffersomyces stipitis/S. cerevisiae consortium were investigated. A fed-batch enzyme saccharification followed by fermentation (SHF) using optimized yeast consortium achieved a maximum ethanol titer of 60 g/L with ethanol yield exceeding 70% of theoretical. Techno-economic analysis was assessed using a fully integrated process flowsheeting model, showing the optimized fed-batch yeast co-culture as the most cost-effective configuration with the ethanol yield of 250 kg-ethanol/ton-bagasse. The minimal ethanol selling price was 26.7 baht/L-ethanol, closed to the current ethanol selling price from cassava-based process. Process sensitivity analyses revealed the potentials for further cost reduction up to 44% by reducing enzyme dosage and increasing ethanol titer. Hence, this study provides an economically viable prototype for high-titer lignocellulosic ethanol production using S. stipitis/S. cerevisiae consortium which may offer better economic value than starch-based process.

Keywords

High-solid fed-batch process

High-titer ethanol fermentation

Yeast consortium technology

Techno-economic analysis

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• ∗ 
  Corresponding author.
  
  

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