Hot water extraction and steam explosion as pretreatments for ethanol production from spruce bark

Research output: Contribution to journalArticle


  • Katariina Kemppainen
  • Jenni Inkinen
  • Jaana Uusitalo
  • Tiina Nakari-Setälä
  • Matti Siika-aho

Research units

  • VTT Technical Research Centre of Finland


Spruce bark is a source of interesting polyphenolic compounds and also a potential but little studied feedstock for sugar route biorefinery processes. Enzymatic hydrolysis and fermentation of spruce bark sugars to ethanol were studied after three different pretreatments: steam explosion (SE), hot water extraction (HWE) at 80 °C, and sequential hot water extraction and steam explosion (HWE + SE), and the recovery of different components was determined during the pretreatments. The best steam explosion conditions were 5. min at 190 °C without acid catalyst based on the efficiency of enzymatic hydrolysis of the material. However, when pectinase was included in the enzyme mixture, the hydrolysis rate and yield of HWE bark was as good as that of SE and HWE + SE barks. Ethanol was produced efficiently with the yeast Saccharomyces cerevisiae from the pretreated and hydrolysed materials suggesting the suitability of spruce bark to various lignocellulosic ethanol process concepts.


Original languageEnglish
Pages (from-to)131-139
Number of pages9
JournalBioresource Technology
Publication statusPublished - Aug 2012
MoE publication typeA1 Journal article-refereed

    Research areas

  • Bark, Enzymatic hydrolysis, Lignocellulosic ethanol, Pretreatment, SSF

ID: 15945123