title: Technical evaluation of a tank-connected food waste disposer system for biogas production and nutrient recovery.
abstract: In this study, a tank-connected food waste disposer system with the objective to optimise biogas production and nutrient recovery from food waste in Malmö was evaluated. The project investigated the source-separation ratio of food waste through waste composition analyses, determined the potential biogas production in ground food waste, analysed the organic matter content and the limiting components in ground food waste and analysed outlet samples to calculate food waste losses from the separation tank. It can be concluded that the tank-connected food waste disposer system in Malmö can be used for energy recovery and optimisation of biogas production. The organic content of the collected waste is very high and contains a lot of energy rich fat and protein, and the methane potential is high. The results showed that approximately 38% of the food waste dry matter is collected in the tank. The remaining food waste is either found in residual waste (34% of the dry matter) or passes the tank and goes through the outlet to the sewer (28%). The relatively high dry matter content in the collected fraction (3-5% DM) indicates that the separation tank can thicken the waste substantially. The potential for nutrient recovery is rather limited considering the tank content. Only small fractions of the phosphorus (15%) and nitrogen (21%) are recyclable by the collected waste in the tank. The quality of the outlet indicates a satisfactory separation of particulate organic matter and fat. The organic content and nutrients, which are in dissolved form, cannot be retained in the tank and are rather led to the sewage via the outlet.
authors.affiliation: Department of Chemical Engineering, Lund University, P.O. Box 124, SE-221 00 Lund, Sweden. Electronic address: asa.davidsson@chemeng.lth.se.
authors.forename: Å
authors.initials: Å
authors.lastname: Davidsson
authors.affiliation: Centro de Gestão Tecnológica - CT2, Rua Moniz de Aragão, No. 360 - Bloco 2, Ilha do Fundão - Cidade Universitária, Rio de Janeiro, RJ 21.941-972, Brazil.
authors.forename: A
authors.initials: A
authors.lastname: Bernstad Saraiva
authors.affiliation: Department of Chemical Engineering, Lund University, P.O. Box 124, SE-221 00 Lund, Sweden.
authors.forename: N
authors.initials: N
authors.lastname: Magnusson
authors.affiliation: VA SYD, Box 191, SE-201 21 Malmö, Sweden; Urban Studies, Malmö University, 205 06 Malmö, Sweden.
authors.forename: M
authors.initials: M
authors.lastname: Bissmont
mesh_terms: D056804:Biofuels; D005502:Food; D008697:Methane; D009584:Nitrogen; D010758:Phosphorus; D012722:Sewage
chemical_list: D056804:Biofuels; D012722:Sewage; D010758:Phosphorus; D009584:Nitrogen; D008697:Methane
keywords: Biogas; Disposer; Food waste; Sorting; Tank system