title: Opportunities and prospects of biorefinery-based valorisation of pulp and paper sludge.
abstract: The paper and pulp industry is one of the major industries that generate large amount of solid waste with high moisture content. Numerous opportunities exist for valorisation of waste paper sludge, although this review focuses on primary sludge with high cellulose content. The most mature options for paper sludge valorisation are fermentation, anaerobic digestion and pyrolysis. In this review, biochemical and thermal processes are considered individually and also as integrated biorefinery. The objective of integrated biorefinery is to reduce or avoid paper sludge disposal by landfilling, water reclamation and value addition. Assessment of selected processes for biorefinery varies from a detailed analysis of a single process to high level optimisation and integration of the processes, which allow the initial assessment and comparison of technologies. This data can be used to provide key stakeholders with a roadmap of technologies that can generate economic benefits, and reduce carbon wastage and pollution load.
authors.affiliation: Department of Process Engineering, University of Stellenbosch, Private Bag X1, Stellenbosch 7602, South Africa.
authors.forename: Lalitha Devi
authors.initials: LD
authors.lastname: Gottumukkala
authors.affiliation: Department of Process Engineering, University of Stellenbosch, Private Bag X1, Stellenbosch 7602, South Africa.
authors.forename: Kate
authors.initials: K
authors.lastname: Haigh
authors.affiliation: Department of Process Engineering, University of Stellenbosch, Private Bag X1, Stellenbosch 7602, South Africa.
authors.forename: François-Xavier
authors.initials: FX
authors.lastname: Collard
authors.affiliation: Department of Process Engineering, University of Stellenbosch, Private Bag X1, Stellenbosch 7602, South Africa.
authors.forename: Eugéne
authors.initials: E
authors.lastname: van Rensburg
authors.affiliation: Department of Process Engineering, University of Stellenbosch, Private Bag X1, Stellenbosch 7602, South Africa. Electronic address: jgorgens@sun.ac.za.
authors.forename: Johann
authors.initials: J
authors.lastname: Görgens
mesh_terms: D019149:Bioreactors; D002482:Cellulose; D005285:Fermentation; D007220:Industrial Waste; D010209:Paper; D012722:Sewage / Q000737:chemistry; D014865:Waste Disposal, Fluid / Q000379:methods*
chemical_list: D007220:Industrial Waste; D012722:Sewage; D002482:Cellulose
keywords: Bioenergy; Biorefinery; Paper sludge; Pyrolysis; Techno-economic modelling