Biomass Fractionation by Hot Compressed Liquid Water

Abstract

Samples of six woody and four herbaceous biomass species were washed with compressed, liquid water for 0 to 15 minutes at 200{\textdegree}--230{\textdegree}C. Between 40 and 60{%} of the sample mass was solubilized. In all cases, 100{%} of the hemicellulose was solubilized, of which 90{%} (on average) was recoverable as monomeric sugar. Concurrently, between 4--22{%} of the cellulose and 35--60{%} of the lignin were also solubilized. The solvolysis process is so facile that the results are practically independent of temperature and time within the range studied. The observed variations occurred primarily as a function of species. High lignin solubilization apparently reduced the ability to recover hemicellulose sugar.