title: Green chemicals from pulp production black liquor by partial wet oxidation.
abstract: To reduce greenhouse gas emissions, more sustainable sources of energy, fuel and chemicals are needed. Biomass side streams such as black liquor, which is a by-product of pulp production, has the potential to be used for this purpose. The aim of the study was the production of carboxylic acids, such as lactic acid, formic acid and acetic acid, from kraft and non-wood black liquor. The processes studied were partial wet oxidation (PWO) and catalytic partial wet oxidation (CPWO). The results show that the yield of carboxylic acid is higher when treated by PWO than the results from CPWO at temperatures of 170 °C and 230 °C. The results shows that the PWO process can increase the yield of carboxylic acids and hydroxy acids in black liquor, reduce lignin content and decrease pH, which makes further separation of the acids more favourable. The hydroxy acids are valuable raw materials for biopolymers, and acetic acid and formic acid are commonly used chemicals conventionally produced from fossil feedstock.
authors.affiliation: Department of Biotechnology and Chemical Technology, Aalto University, Finland raja.hassan@aalto.fi.
authors.forename: Hassan Raja
authors.initials: HR
authors.lastname: Muddassar
authors.affiliation: Department of Biotechnology and Chemical Technology, Aalto University, Finland.
authors.forename: Kristian
authors.initials: K
authors.lastname: Melin
authors.affiliation: Department of Biotechnology and Chemical Technology, Aalto University, Finland.
authors.forename: Daniela
authors.initials: D
authors.lastname: de Villalba Kokkonen
authors.affiliation: Department of Biotechnology and Chemical Technology, Aalto University, Finland.
authors.forename: Gerard Viader
authors.initials: GV
authors.lastname: Riera
authors.affiliation: Department of Biotechnology and Chemical Technology, Aalto University, Finland.
authors.forename: Sarwar
authors.initials: S
authors.lastname: Golam
authors.affiliation: Department of Biotechnology and Chemical Technology, Aalto University, Finland.
authors.forename: Jukka
authors.initials: J
authors.lastname: Koskinen
mesh_terms: D018533:Biomass; D002264:Carboxylic Acids / Q000737:chemistry*; D055772:Green Chemistry Technology; D006863:Hydrogen-Ion Concentration; D007220:Industrial Waste / Q000032:analysis*; D008031:Lignin / Q000737:chemistry; D010084:Oxidation-Reduction; D010209:Paper; D013696:Temperature; D018505:Waste Management / Q000379:methods*; D062065:Wastewater / Q000032:analysis
chemical_list: D002264:Carboxylic Acids; D007220:Industrial Waste; D008031:Lignin; D062065:Wastewater
keywords: Wet oxidation; black liquor; catalytic wet oxidation; partial wet oxidation; pulp and paper waste treatment; soda non-wood cooking liquor; spent liquor