English title: Evaluation of synergetic effects of integrated recirculating aquaculture systems with water electrolysis units Norsk tittel: Evaluering av synergetiske effekter av integrerte resirkulerende akvakultursystemer med vannelektrolyseenheter
Abstract
Recirculating aquaculture systems (RAS) are developing rapidly as a pathway towardsa more sustainable and efficient aquaculture industry. Such facilities allow for precisecontrol of parameters involved in fish farming, such as oxygenation units for providingoxygen and replenish oxygen saturation levels in the recirculated water. In order tolocally supply the oxygen demand to these facilities, water electrolysis technology maybe a complementary solution of which oxygen and heat are secondary products, typicallyunutilized in conventional production units, in addition to the main product which ishydrogen.
To study the synergetic effects of combining RAS facilities for Atlantic salmon andwater electrolysis systems, three pre-defined case studies of varying sizes have beenestablished with regards to the technical feasibility, impact on the production cost ofhydrogen, as well as sensitivity analyses of relevant economical variables. Simulation ofthe alkaline water electrolysis process is also carried out through Aspen Plus software,and the varying oxygen demand during the growth of Atlantic salmon is modeled foreach case study presented in this report.
The three case studies show considerable economical benefits through scale-up of thecombined facilities. A promising hydrogen production cost of 27.74 kr/kg H2 wasachieved for the largest facility (case 3), producing more than 50 tonnes of O2 per day,where revenues from oxygen sales and district heating are included. A more detailedtechno-economic analysis, optimization of the general concept, a study of including alternativeenergy sources such as wind and solar, as well as further work with the simulatedprocess in Aspen Plus may be recommended for future studies of the established casesin this paper.