title: Hydrothermal carbonization of industrial mixed sludge from a pulp and paper mill.
abstract: Mixed sludge from a pulp and paper mill was hydrothermally carbonized at 180-260°C for 0.5-5h with the use of HCl or NaOH for determining the effect of acid and base additions during sludge carbonization. Based on the results carbonization was mainly governed by dehydration, depolymerization and decarboxylation of sludge components. Additive type had a statistically significant effect on hydrochar carbon content and carbon and energy yield, of which especially energy yield increased through the use of HCl. The theoretical energy efficiencies of carbonization increased with decreasing reaction temperature, retention time and the use of HCl and suggested that the energy requirement could be covered by the energy content of attained hydrochar. The BOD5/COD-ratios of analyzed liquid samples indicated that the dissolved organic components could be treated by conventional biological methods.
authors.affiliation: Swedish University of Agricultural Sciences, Department of Forest Biomaterials and Technology, Skogsmarksgränd, 90183 Umeå, Sweden. Electronic address: makela.m.aa@m.titech.ac.jp.
authors.forename: Mikko
authors.initials: M
authors.lastname: Mäkelä
authors.affiliation: University of Alicante, Department of Chemical Engineering, P.O. Box 99, 03080 Alicante, Spain.
authors.forename: Verónica
authors.initials: V
authors.lastname: Benavente
authors.affiliation: University of Alicante, Department of Chemical Engineering, P.O. Box 99, 03080 Alicante, Spain.
authors.forename: Andrés
authors.initials: A
authors.lastname: Fullana
mesh_terms: D057919:Biological Oxygen Demand Analysis; D018533:Biomass; D002244:Carbon / Q000737:chemistry*; D007220:Industrial Waste; D009930:Organic Chemicals / Q000737:chemistry; D010209:Paper; D011108:Polymers / Q000737:chemistry; D011312:Pressure; D025341:Principal Component Analysis; D012722:Sewage / Q000737:chemistry*; D013431:Sulfates; D013696:Temperature; D014865:Waste Disposal, Fluid / Q000379:methods*
chemical_list: D007220:Industrial Waste; D009930:Organic Chemicals; D011108:Polymers; D012722:Sewage; D013431:Sulfates; D002244:Carbon
keywords: Biosolids; Hydrothermal treatment; Sludge treatment; Waste biomass; Wet torrefaction