title: A process for producing lignin and volatile compounds from hydrolysis liquor.
abstract: BACKGROUND
  Hot water hydrolysis process is commercially applied for treating wood chips prior to pulping or wood pellet production, while it produces hydrolysis liquor as a by-product. Since the hydrolysis liquor is dilute, the production of value-added materials from it would be challenging.
  
  
  RESULTS
  In this study, acidification was proposed as a viable method to extract (1) furfural and acetic acid from hot water hydrolysis liquor and (2) lignin compounds from the liquor. The thermal properties of the precipitates made from the acidification of hydrolysis liquor confirmed the volatile characteristics of precipitates. Membrane dialysis was effective in removing inorganic salts associated with lignin compounds. The purified lignin compounds had a glass transition temperature (Tg) of 180-190 °C, and were thermally stable.
  
  
  CONCLUSIONS
  The results confirmed that lignin compounds present in hot water hydrolysis liquor had different characteristics. The acidification of hydrolysis liquor primarily removed the volatile compounds from hydrolysis liquor. Based on these results, a process for producing purified lignin and precipitates of volatile compounds was proposed.
authors.affiliation: Johan Gadolin Process Chemistry Center, Laboratory of Inorganic Chemistry, Åbo Akademi University, Piispankatu 8, 20500 Turku, Finland.
authors.forename: Tooran
authors.initials: T
authors.lastname: Khazraie
authors.affiliation: Chemical Engineering Department, Lakehead University, 955 Oliver Road, Thunder Bay, ON P7B 5E1 Canada.
authors.forename: Yiqian
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: Chemical Engineering Department, Lakehead University, 955 Oliver Road, Thunder Bay, ON P7B 5E1 Canada.
authors.forename: Dmitry
authors.initials: D
authors.lastname: Tarasov
authors.affiliation: Chemical Engineering Department, Lakehead University, 955 Oliver Road, Thunder Bay, ON P7B 5E1 Canada.
authors.forename: Weijue
authors.initials: W
authors.lastname: Gao
authors.affiliation: Chemical Engineering Department, Lakehead University, 955 Oliver Road, Thunder Bay, ON P7B 5E1 Canada.|Bioeconomy Technology Centre, FPInnovations, 2001 Neebing Ave, Thunder Bay, ON P7E 6S3 Canada.
authors.forename: Jacquelyn
authors.initials: J
authors.lastname: Price
authors.affiliation: Johan Gadolin Process Chemistry Center, Laboratory of Inorganic Chemistry, Åbo Akademi University, Piispankatu 8, 20500 Turku, Finland.
authors.forename: Nikolai
authors.initials: N
authors.lastname: DeMartini
authors.affiliation: Johan Gadolin Process Chemistry Center, Laboratory of Inorganic Chemistry, Åbo Akademi University, Piispankatu 8, 20500 Turku, Finland.
authors.forename: Leena
authors.initials: L
authors.lastname: Hupa
authors.affiliation: Chemical Engineering Department, Lakehead University, 955 Oliver Road, Thunder Bay, ON P7B 5E1 Canada.
authors.forename: Pedram
authors.initials: P
authors.lastname: Fatehi
keywords: Acidification; Biorefining; Furfural; Hydrolysis; Lignin