Sun, seawater and sewage: microalgae can thrive on feedstock that is freely available and the resulting biomass can be used to make high-value products such as biostimulants and biopesticides. But can this be done viably on a large scale? Let us demonstrate, say EU-funded researchers building an integrated biorefinery.
© Valery Bocman - fotolia.com
The SABANA project focuses on a biorefinery approach by which microalgae fed on suitable effluents and seawater serve to produce a variety of useful substances for agriculture and aquaculture. Particular attention is dedicated to the environmental and economic sustainability of the processes that the partners are developing or upgrading in view of the construction of a commercial-scale demonstrator facility.
Partners from five countries are involved in this four-year endeavour launched in December 2016, which is led from Spain by the University of Almería. The biorefinery approach they are championing is a way to recover nutrients that might otherwise go down the drain notably phosphorus, which the EU cannot afford to squander. The SABANA team intends to achieve a zero-waste process that requires very little energy and does not add to the pressure on limited freshwater supplies.
More specifically, three types of waste are to feed the partners microalgae: sewage, pig manure and the liquid separated out from sludge by means of centrifugation. The biomass grown on these nutrient-rich effluents will then be processed to derive a variety of bio-based products, which include pesticides, biostimulants and feed additives. Residues of the projects harvests are to be converted into biofertiliser, as well as feed for use in aquaculture.