Energy efficient and climate friendly cooling, freezing and heating onboard fishing vessels

The national and international fishing industry faces major challenges in reducing climate gas emissions. To cope with this, new fuels and engine technologies for propulsion of fishing vessels are under rapid development. But it is not only the fuel consumption related to propulsion that contributes to the emissions of climate gases. On board there are also energy consuming equipment to keep the catch refrigerated, ensuring product quality and shelf life. There are also systems for producing the hot water on board. The ambition of the project was to contribute to developing energy-efficient and climate friendly systems for cold and heat production onboard fishing vessels. A refrigeration plant contributes to global warming in two different ways: consumption of energy (electricity) to drive the plant and leakage of the refrigerants. Several refrigerants have a significant global warming impact. Norway is at the forefront of replacing these refrigerants with natural refrigerants, which have no negative environmental impact. Further development of these systems has been an important part of the project, as well as global transferring of knowledge and technology. The results have been disseminated internationally through participation in conferences, collaboration with other projects and open access to the publications. An additional way to reduce climate impact is to reduce the energy consumption for the production of cold and heat by integrating these systems. Concepts for such integrated solutions have already been developed for supermarkets. In this project, we have investigated the performance of a transcritical CO2 heat pump chiller (two-stage evaporator: gravity fed/ejector fed), both in the laboratory and with modelling. It is too early to use it on board fishing vessels, but the results show that this combination can result in compact and energy-efficient systems. Another concept that has been evaluated in the project is the utilization of cold from LNG-driven ships. We have seen that there is a potential for this, for example for chilling of the fish on the way back to land, but there could be challenges in how to design these systems. We have also investigated possibilities of improving processes and technology for handling the rest raw materials and hydrolysates. These processes require as much energy as steam/heat, so we analyzed alternative methods with freeze concentration. This is gentler on the products, but the technology must be developed to be more robust before it is included onboard. The project, which is led by SINTEF Ocean and includes SINTEF Energy and NTNU as research partners, was carried out in close cooperation with industrial partners and the international scientific community. We have had nine workshops in the project, where the first was with Norwegian industry in 2019 and the following three (2020 and 2021) were conducted as Teams meeting, including international participants. We had a project meeting in November 2021 where all industry partners were invited. In November 2021, we had a workshop on thermal energy storage, which was a collaboration between 4 SINTEF/NTNU projects. A similar workshop was held at the end of 2022. We had a workshop in Ålesund in September 2022, summarising most of the project's activities. Many industry partners participated there. Another workshop was organized during the International Congress of Refrigeration (Paris, August 2023) on the topic “Training on clean cooling and heating solutions”. We have had many other meetings in the project, especially within the industry cases. Seven reports have been published during the project, for example: "Alternative Fuels and Propulsion Systems for Fishing vessels", "Carbon Footprint of Fisheries - a review of standards methods and tools" and "Equipment and systems onboard fishing vessels". We have published 18 journal and conference papers, for example International Journal of Refrigeration, IIR conference on sustainability and the cold chain, IIR Gustav Lorentzen Conference on natural refrigerants, and IIR Conference on Ammonia and CO2 Refrigeration Technologies. We have had eight master's students that delivered from 2020 to 2023. They have presented their work to the project group, but also at conferences, for example the Norwegian refrigeration society’s annual meeting. Some of the Master students are now employed by CoolFish partners. We have also been on a research cruise, where we gathered data from a fishing vessel, which are shared via scientific publications. Most of the reports, presentations and newsletters are available on the project webpage: www.sintef.no/en/projects/coolfish

CoolFish har hatt en innvirkning på den nasjonale kunnskapsbasen, spesielt innen fiskerisektoren og utstyrsleverandører for denne bransjen. Kunnskap og forståelse har også økt blant deltakerne, som inkluderte bransjedeltakere, studenter og det vitenskapelige samfunnet. Resultatene fra prosjektet, som artikler, måledata, presentasjoner og annen formidling, har også nådd et bredere publikum, siden de er åpent tilgjengelige for nedlasting fra websiden til prosjektet. CoolFish har også hatt innvirkning på den internasjonale kunnskapsbasen. Presentasjon på internasjonale konferanser og diskusjoner med aktører fra andre land har ført til samarbeid med andre land, for eksempel med India i prosjektet INDEE+. Resultatene fra prosjektet har vist at mange fiskefartøy over hele verden fremdeles bruker R22 (HCFC) i sine kjølesystemer. Dette må endres til fordel for naturlige kjølemidler, som har vist seg å være en suksesshistorie for eierne av fartøyene i Norge. Vi vil fortsette å formidle dette til vi ser en betydelig endring, for eksempel i tilbakemeldingene til Europakommisjonen. De åtte masterstudentene som har deltatt i prosjektet, vil bringe både sitt arbeid og annen innsikt fra prosjektet til sine nåværende eller fremtidige samarbeidspartnere. CoolFish har samarbeidet med andre prosjekter og har også fremmet ideer for nye prosjekter, hvorav noen allerede er søkt om, for eksempel lagring av lavtemperatur termisk energi med CO2 og utvikling av veldig små RSW-systemer for fiskefartøy. Prosjektet har bidratt til verdiskaping og økt konkurranseevne for den norske industrien, der denne teknologien resulterer i fiskeprodukter av høy kvalitet, produsert med lavt energiforbruk og lavt klima- og miljøpåvirkning. Gjennom CoolFish har det blitt utviklet en ny metode som brukes i i forbindelse med utvinning av proteiner fra restråstoff. Restråstoffet er alt på fisken utenom filet og denne andelen kan utgjøre rundt halvparten av fisken. Metoden baserer seg på å produsere iskrystaller som kan skilles fra den proteinrike vannløsiningen (hydrolysat). Ved separasjon av iskrystaller oppnår man en økning av proteinkonsentrasjonen ved meget lave temperaturer som er positivt for kvalitet og holdbarhet til produktet, slik at denne kan brukes til høyverdiingredienser i for eksempel sensitive bioingredienser eller mat. Utvikling av en to-trinns fordamperløsning i CO2 kjøleanlegg med en ejektor er også et resultat av CoolFish-samarbeidet. Denne spesielle prosessen muliggjør å vedlikeholde temperaturen i RSW tanker og samtidig akkumulere kulde ved å produsere is paralelt . Denne applikasjoner kan brukes på fiskebåter men også i landbaserte anlegg.

In CoolFish the main objective is to increase energy efficiency of the utility systems (cooling, freezing and heating) onboard fishing vessels. The up-coming change towards new propulsion systems requires and enables development of new efficient utility systems concepts. One example is the possibility to use surplus cold from the fuel system on LNG-driven vessels to cover a significant portion of cooling and freezing demand for fish preservation. Another example relates to vessels with hybrid or electrical propulsion, which do not have the same quantity of surplus heat available as vessels with conventional diesel engines. This can be solved by utilizing waste heat from the refrigeration system, in combination with a heat pump. The heating demand onboard includes room and tap water heating, but also specific processes like onboard enzymatic hydrolysis used for utilization of marine raw material, which is under development. Previous research by SINTEF and NTNU on systems using natural refrigeration has built up a solid foundation for further development of the systems and adaptation to new implementations. MMC First Process is an active participant in CoolFish, with innovative solutions and modern technology, especially with natural refrigerants. Ulmatec Pyro develops heating and energy management systems and have close collaboration with MMC. Liegruppen and Sørheim Holding are planning LNG-driven ships, together with Salt design. In Norway, most fishing vessels use natural refrigerants (ammonia and CO2), but globally most fishing vessels use R22 as refrigerant. This refrigerant has both ozone depleting and global warming potential. Another objective of CoolFish is therefore to spread the knowledge about harmful refrigerants, together with the potential of natural refrigerant systems. A technology hub for research and development of natural refrigeration systems will be initiated during CoolFish and the goal is to continue it beyond the end of the project period.