Pre-extraction of hemicelluloses and subsequent kraft pulping part II: Acid- And autohydrolysis

Aspen wood chip samples were subjected to hot water treatments (autohydrolysis) with and without sulfuric acid to extract hemicelluloses. A liquor-to-wood ratio of 4:1 was used at temperatures from 130° to 210°C and H₂SO₄ concentrations in the range from 0% to 1% (w/v), with treatment times up to 4.5 h. Researchers analyzed wood residues and their corresponding hydrolysates, and determined the most suitable conditions for the extraction. Additional information on the suitability of wood residues for pulping purposes is also considered.