title: Acidification of prehydrolysis liquor and spent liquor of neutral sulfite semichemical pulping process.
abstract: Acidification has been commercialized for producing kraft lignin from black liquor of kraft pulping process. This work intended to evaluate the effectiveness of acidification in extracting lignocelluloses from the spent liquor of neutral sulfite semichemical pulping (NSSC) process and from prehydrolysis liquor (PHL) of kraft-based dissolving pulp production process. The results showed that the NSSC and PHL spent liquors had some lignin-carbohydrate complexes (LCC), and that the square weighted counts of particles with a chord length of 50-150μm in the spent liquors were significantly increased as pH dropped to 1.5. Interestingly, the acidification reduced the lignosulfonate/lignin content of NSSC and PHL by 13% or 20%, while dropped their oligosugars content by 75% and 38%, respectively. On a dry basis, the precipitates had more carbon, hydrogen and a high heating value of 18-22MJ/kg, but less oxygen, than spent liquors. The precipitates of PHL could be used as fuel.
authors.affiliation: Key Laboratory of Pulp and Paper Science and Technology of Ministry of Education, Qilu University of Technology, Jinan 250353, China; Chemical Engineeriang Department, Lakehead University, 955 Oliver Road, Thunder Bay, Ontario P7E 5E1, Canada. Electronic address: pfatehi@lakeheadu.ca.
authors.forename: Pedram
authors.initials: P
authors.lastname: Fatehi
authors.affiliation: Chemical Engineeriang Department, Lakehead University, 955 Oliver Road, Thunder Bay, Ontario P7E 5E1, Canada.
authors.forename: Weijiue
authors.initials: W
authors.lastname: Gao
authors.affiliation: Chemical Engineeriang Department, Lakehead University, 955 Oliver Road, Thunder Bay, Ontario P7E 5E1, Canada; Tianjin Key Laboratory of Pulping and Papermaking, Tianjin University of Science and Technology, Tianjin 300457, China.
authors.forename: Yonghui
authors.initials: Y
authors.lastname: Sun
authors.affiliation: Chemical Engineeriang Department, Lakehead University, 955 Oliver Road, Thunder Bay, Ontario P7E 5E1, Canada.
authors.forename: Mehdi
authors.initials: M
authors.lastname: Dashtban
mesh_terms: D019342:Acetic Acid / Q000737:chemistry; D057919:Biological Oxygen Demand Analysis; D001709:Biotechnology; D002241:Carbohydrates / Q000737:chemistry*; D002244:Carbon / Q000737:chemistry; D005662:Furaldehyde / Q000737:chemistry; D006358:Hot Temperature; D006859:Hydrogen / Q000737:chemistry; D006863:Hydrogen-Ion Concentration; D008031:Lignin / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy; D008970:Molecular Weight; D010100:Oxygen / Q000737:chemistry; D010316:Particle Size; D013447:Sulfites / Q000737:chemistry*
chemical_list: D002241:Carbohydrates; D013447:Sulfites; C036909:lignocellulose; D002244:Carbon; D006859:Hydrogen; C076151:Kraft lignin; D008031:Lignin; D005662:Furaldehyde; D019342:Acetic Acid; D010100:Oxygen
keywords: Acidification; Hemicellulose; Lignin; Lignin carbohydrate complex; Particle size; Spent liquor