title: Pulsed corona discharge oxidation of aqueous lignin: decomposition and aldehydes formation.
abstract: Lignin is the mass waste product of pulp and paper industry mostly incinerated for energy recovery. Lignin is, however, a substantial source of raw material for derivatives currently produced in costly wet oxidation processes. The pulsed corona discharge (PCD) for the first time was applied to lignin oxidation aiming a cost-effective environmentally friendly lignin removal and transformation to aldehydes. The experimental research into treatment of coniferous kraft lignin aqueous solutions was undertaken to establish the dependence of lignin oxidation and aldehyde formation on the discharge parameters, initial concentration of lignin and gas phase composition. The rate and the energy efficiency of lignin oxidation increased with increasing oxygen concentration reaching up to 82 g kW-1 h-1 in 89% vol. oxygen. Oxidation energy efficiency in PCD treatment exceeds the one for conventional ozonation by the factor of two under the experimental conditions. Oxidation at low oxygen concentrations showed a tendency of the increasing aldehydes and glyoxylic acid formation yield.
authors.affiliation: Department of Chemical Technology, Lappeenranta University of Technology, Skinnarilankatu 34, 53850 Lappeenranta, Finland. iris.panorel@lut.fi
authors.forename: Iris
authors.initials: I
authors.lastname: Panorel
authors.affiliation: Department of Chemical Technology, Lappeenranta University of Technology, Skinnarilankatu 34, 53850 Lappeenranta, Finland.
authors.forename: Laura
authors.initials: L
authors.lastname: Kaijanen
authors.affiliation: lnstitute of High Technology Physics, Tomsk Polytechnic University, 2A Lenin Ave., Tomsk 634028, Russia.
authors.forename: Iakov
authors.initials: I
authors.lastname: Kornev
authors.affiliation: Department of Chemical Technology, Lappeenranta University of Technology, Skinnarilankatu 34, 53850 Lappeenranta, Finland.
authors.forename: Sergei
authors.initials: S
authors.lastname: Preis
authors.affiliation: Department of Chemical Technology, Lappeenranta University of Technology, Skinnarilankatu 34, 53850 Lappeenranta, Finland.
authors.forename: Marjatta
authors.initials: M
authors.lastname: Louhi-Kultanen
authors.affiliation: Department of Chemical Technology, Lappeenranta University of Technology, Skinnarilankatu 34, 53850 Lappeenranta, Finland.
authors.forename: Heli
authors.initials: H
authors.lastname: Sirén
mesh_terms: D000447:Aldehydes / Q000138:chemical synthesis* / Q000528:radiation effects*; D004307:Dose-Response Relationship, Radiation; D004574:Electromagnetic Fields; D008031:Lignin / Q000737:chemistry* / Q000528:radiation effects*; D010084:Oxidation-Reduction / Q000528:radiation effects; D010100:Oxygen / Q000737:chemistry*; D011829:Radiation Dosage; D014867:Water / Q000737:chemistry*
chemical_list: D000447:Aldehydes; D014867:Water; C076151:Kraft lignin; D008031:Lignin; D010100:Oxygen