Biorefineries at poultry farms: a perspective for sustainable development

Abstract

Poultry litter (PL) is one of the drier and bulkier manures produced in intensive agriculture. Land spreading is considered the most common treatment option for PL; however, this causes large atmospheric greenhouse emissions and consequently a high negative environmental impact. PL has several factors that limit its sustainable use as an energy source, and thus there is still a need for more studies about sustainable waste management. The paper aims at: (i) proposing sustainable pathways in order to maximise the PL valorisation process, based on previous experiences described in the literature; and (ii) showing the advantages of reforming poultry farms into biorefineries in Cuba. Combinations of techniques are used to increase PL valorisation, but only by modulating the theoretical data has an improvement occurred. In this work, pathways for thermo- and bioconversion processes are proposed which involve four major technologies for converting PL into useful energy and fertiliser, being pyrolysis/gasification, hydrothermal carbonisation and anaerobic digestion as key conversion technologies. Including technologies for nutrient recovery in the proposed pathways would allow better agricultural applications. The treatment of PL in biorefineries in Cuba would have a positive impact on the economy through income generation and savings resulting from reductions in imports (i.e. fossil fuels and agrochemicals), employment creation, improved living conditions and development in rural communities. Future studies should be aimed at evaluating the various proposed pathways in order to maximise the PL valorisation process, in addition to a marketing study of the products generated through the biorefineries at poultry farms. © 2020 Society of Chemical Industry (SCI)