Energetic and Economic Evaluation of Zero-Waste Fish Co-Stream Processing.

Kęstutis Venslauskas,Vidmantas Župerka,Revilija Mozūraitytė,Rasa Šližytė,Petteri Kangas,Marja Nappa,Kęstutis Navickas

doi:10.3390/ijerph18052358

Abstract

This study evaluates the possibility of recovery of high-quality valuable fish oil and proteins from fish co-streams by traditional means or a combination of several technologies. A techno-economically feasible and sustainable zero-waste process is needed for full utilisation of this co-stream’s potential. This study aims to determine the energy efficiency and economic feasibility of four different zero-waste bio-refineries based on salmon filleting co-streams. The study covers four concepts: (I) biogas and fertiliser production from salmon co-streams, (II) fish silage production, (III) thermal processing of salmon co-streams for producing oil, protein concentrate, and meal, and (IV) novel two-stage thermal and enzymatic process for producing high-quality oil and protein hydrolysate, while the solid residue is converted to biogas and fertilisers. Monte Carlo simulation is used to evaluate uncertainties in economic evaluation. The results show that the two-stage processing of fish co-streams leads to recovery of both high-quality marine oil and proteins, showing the largest profitability and return on investment during the economic analysis. It is a more tempting option than the currently used thermal treatment or traditional silage processes. The possibility of producing food-grade fish protein hydrolysate is the biggest benefit here. Concepts studied are examples of zero-waste processing of bioproducts and illustrate the possibilities and benefits of fully utilising the different fractions of fish as fillets, oil, protein, fertilisers, and energy production.

Highlights

The world is concerned about the use of natural resources and the deployment of sustainable practices and goals
Fish processing into different products on an industrial level generates a significant quantity of co-streams, which are often considered as low-value products or even can be wasted without any attempt to recover
An energetic and economic evaluation of four technological concepts for the processing of salmon processing co-streams is presented in this study: (I) biogas and fertiliser production from salmon co-streams, (II) fish silage production, (III) thermal processing of salmon co-stream for producing oil, protein concentrate, and meal, and (IV) novel two-stage thermal and enzymatic process for producing high-quality oil and protein hydrolysate, while the solid residue is converted to biogas and fertilisers

Summary

Introduction

The world is concerned about the use of natural resources and the deployment of sustainable practices and goals. Greater attention should be given to the implementation of sustainable agriculture, fisheries, and aquaculture, solving several challenges including water scarcity and food waste problems [1]. Fish processing into different products on an industrial level generates a significant quantity of co-streams, which are often considered as low-value products or even can be wasted without any attempt to recover. Such a point of view is unattractive in terms of circular economy [2]. Aquaculture is the fastest growing producer of animal protein in the world.

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Discussion

Conclusion