Optimization of steam pretreatment of corn stover to enhance enzymatic digestibility

Eniko Varga, K. Réczey, Guido Zacchi

Research output: Contribution to journalArticle

122 Citations (Scopus)

Abstract

Among the available agricultural byproducts, corn stover, with its yearly production of 10 million t (dry basis), is the most abundant promising raw material for fuel ethanol production in Hungary. In the United States, more than 216 million t of corn stover is produced annually, of which a portion also could possibly be collected for conversion to ethanol. However, a network of lignin and hemicellulose protects cellulose, which is the major source of fermentable sugars in corn stover (approx 40% of the dry matter [DM]). Steam pretreatment removes the major part of the hemicellulose from the solid material and makes the cellulose more susceptible to enzymatic digestion. We studied 12 different combinations of reaction temperature, time, and pH during steam pretreatment. The best conditions (200°C, 5 min, 2% H2SO 4) increased the enzymatic conversion (from cellulose to glucose) of corn stover more then four times, compared to untreated material. However, steam pretreatment at 190°C for 5 min with 2% sulfuric acid resulted in the highest overall yield of sugars, 56.1 g from 100 g of untreated material (DM), corresponding to 73% of the theoretical. The liquor following steam explosion was fermented using Saccharomyces cerevisiae to investigate the inhibitory effect of the pretreatment. The achieved ethanol yield was slightly higher than that obtained with a reference sugar solution. This demonstrates that baker's yeast could adapt to the pretreated liquor and ferment the glucose to ethanol efficiently.

Original languageEnglish
Pages (from-to)509-523
Number of pages15
JournalApplied Biochemistry and Biotechnology - Part A Enzyme Engineering and Biotechnology
Volume114
Issue number1-3
DOIs
Publication statusPublished - Mar 2004

Fingerprint

Steam
Zea mays
Ethanol
Cellulose
Sugars
Yeast
Glucose
Saccharomyces cerevisiae
Ethanol fuels
Hungary
Explosions
Lignin
Sulfuric acid
Byproducts
Digestion
Raw materials
Temperature
hemicellulose

Keywords

  • Bioethanol
  • Corn stover
  • Hydrolysis
  • Pretreatment
  • Steam explosion

ASJC Scopus subject areas

  • Biochemistry, Genetics and Molecular Biology(all)
  • Biochemistry
  • Biotechnology
  • Bioengineering

Cite this

Optimization of steam pretreatment of corn stover to enhance enzymatic digestibility. / Varga, Eniko; Réczey, K.; Zacchi, Guido.

In: Applied Biochemistry and Biotechnology - Part A Enzyme Engineering and Biotechnology, Vol. 114, No. 1-3, 03.2004, p. 509-523.

Research output: Contribution to journalArticle

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