Salmon Fish Waste Biogas is not a pleasant thought. But, undeniably, the fishing and fish cultivation industries necessarily produce a lot of organic waste. In particular salmon fish waste and fish waste in general was until recently simply thrown into landfills.
Thankfully, that is not necessary any longer. Not since the development of fish waste biogas plants, where Scottish salmon producers have been pioneering themselves a sustainable future in aquaculture, by producing valuable renewable energy from their fish waste.
Growing importance of sustainable aquaculture
As global populations grow and the demand for protein-rich foods increases, aquaculture has positioned itself as a critical solution to this surging requirement.
According to a 2020 report from the Food and Agriculture Organization of the United Nations (FAO), fish farming now accounts for about half of all fish consumed worldwide. (See Statista Chart reproduced below.)
However, the intensification of aquaculture has presented challenges, notably the environmental impact of waste management. As an alternative, some innovative stakeholders are now focusing on converting this waste into a valuable resource — biogas.
Among the wide range of species cultivated, salmon is highly sought after, with salmon farms generating substantial quantities of waste. In response, researchers are developing innovative technologies to transform salmon waste into biogas, which holds promising benefits not only for the industry but also for the environment and energy sector.
Understanding the Biogas Process
Biogas is produced through anaerobic digestion, a series of biological processes where microorganisms break down biodegradable material in the absence of oxygen. The primary constituents of biogas are methane and carbon dioxide, and they can be used directly for heating, electricity production, and as a renewable substitute for natural gas.
In the context of salmon farming, the waste generated — discarded food from fish waste processing, a mix of faeces, uneaten feed, and mortalities — can be processed in anaerobic digesters to produce biogas.
This concept of extracting energy from waste (EfW) aligns with the broader goal of a circular economy, where waste from one process becomes a valuable input for another.
Benefits of Biogas from Salmon Fish Waste
Sustainability in Aquaculture
Converting waste into biogas can significantly reduce the environmental burden of aquaculture. It minimizes the amount of waste released into water bodies, mitigating potential impacts on water quality and aquatic ecosystems. Additionally, the use of biogas can help the industry reduce its reliance on fossil fuels, decreasing greenhouse gas emissions and enhancing overall sustainability.
Salmon fish waste biogas presents a considerable potential source of renewable energy. With aquaculture operations spread globally, such waste-to-energy systems could provide a localized energy source, promoting energy security and self-sufficiency. This aspect is particularly appealing to remote and off-grid farming operations where energy access might be a challenge.
The anaerobic digestion process yields not only biogas but also nutrient-rich biofertilizer. This byproduct, called digestate, can be used in agriculture, thus creating a resource loop that links aquaculture with terrestrial farming systems and supports soil health.
The Bigger Picture: Fish Waste Biogas
The concept of transforming fish waste into biogas is not exclusive to salmon farming. Across the globe, fisheries and other forms of aquaculture generate vast amounts of waste. All of this could potentially be used as feedstock for biogas production.
Waste from fish processing industries, typically considered a disposal problem, could be viewed as an untapped energy resource. This strategy would not only help these industries manage their waste efficiently but could also provide an additional revenue stream, making the seafood sector more economically resilient.
We are delighted to re-publish the following Press Release Case Study of a Scottish Salmon Company (SSC) Award in 2020 which was aided by a Salmon Fish Waste Biogas Project and installation of a Landia pasteurizer.
Press Release 6 October 2020:
Scottish Salmon Company (SSC) Award Aided by Salmon Fish Waste Biogas and Landia
Waste Salmon for Biogas Recognised with Top Aquaculture Award
The Scottish Salmon Company (SSC) has won the Community Initiative Award at the 2020 Aquaculture Awards for its work with the Outer Hebrides Local Energy Hub (OHLEH) project on the Isle of Lewis – the first local circular economy of its kind in Scotland.
The success of the project, which sees fish waste (transferred from SSC’s processing plant) co-digested with household food and garden waste in an anaerobic digester (AD), is due partly to the installation of a Landia pasteurizer, as Donnie Macmillan, Plant Manager at the Comhairle nan Eilean Siar (Western Isles Council) Creed Integrated Waste Management Facility (IWMF), explains:
“Firstly, thoroughly deserved recognition must go to our partners in the OHLEH project; the Scottish Salmon Company, Pure Energy Centre (PEC), Community Energy Scotland and the funding by the Scottish Government Local Energy Challenge Fund. Behind the scenes with our very conscientious team here at Creed, we also invested in top quality, long-lasting equipment, including the Landia Pasteurizer, which allows us to process a 7-cubic ton batch per shift of waste salmon for our AD/biogas process. This is waste that would otherwise have been landfilled, so the creation instead of clean, renewable energy is a clear win-win for everybody on the Isle of Lewis and an example to the whole of Scotland and beyond as to what can be achieved with common goals”.
In addition to the continued success of its equipment on the Isle of Lewis, Landia has just been chosen to supply two of its pasteurizers for a new state-of-the-art waste-to-energy biogas plant in Romania. Set to play a crucial role in eliminating biohazards by heating biomass to a minimum of 72°C for one-hour batch processes, the Landia BioChop units will also enable the final digestate to be utilized safely as a high-quality fertilizer.
Salmon Waste and Salmon Industry Developments Toward Sustainability of Salmon Production
Salmon Recycling: Waste Not, Want Not
Land-based salmon product is a concept that reduces the local environmental impact through an increased level of production control and an increased potential to integrate fish waste disposal into the developing circular economy wherever salmon farming is located. The aim of salmon producers will be to use clean, natural water which is taken from the sea, and control the production environment. That prevents infection with and spreading of lice, other parasites and disease.
There will be measures taken to ensure that there is not any risk of salmon escaping from these farms. Wastewater treatment and sludge recycling will minimise the environmental footprint, and represent one of the contributions to a cyclical economy.
Salmon producers in Scotland and throughout the EU are devoted to recycling and reclaiming wastes by using a number of methods in salmon.
The intention is not only to remove all hazardous waste in a way that is safe for the environment but also to implement all opportunities for waste reduction, while also that can saving money. All new or slightly used, unwanted products will be, wherever possible, prevented from entering the waste stream and be made available for reuse by the local community.
Pledges of the sort outlined above are very necessary for an industry where profitability can be achieved while still carrying out waste practices. An example of the potential for a waste problem in the salmon industry can be seen in a case study of a salmon farming project by Sitka Tribal Enterprises. The project was to produce Japanese Coho salmon for the roe industry. Salmon used for roe harvests are traditionally discarded. Only the roe sacks from mature female Coho Salmon are used.
The rest of the fish is discarded as waste. In 1998, the US EPA funded Sitka Tribal Enterprises through a recycling grant. This grant was used to develop an aerated static pile composting facility processing fish waste (whole fish from the Coho Roe industry, as well as Black Cod and Red Snapper, heads and viscera) with wood chip co-disposal from the local timber industry. This is not perfect circularity but is far better than landfill fish waste.
Salmon Waste to Power Jet Airliners
Waste from salmon farms in Norway may soon be used to power jet airliners, including those carrying seafood to Asia. The large BioKraft Biofuel Plant is turning salmon waste into jet fuel. Millions of Kroner is being invested in the large BioKraft Biofuel Plant near the town of Skogn in central Norway to produce ‘green’ gasoline for planes. The project is being carried out in collaboration with the Norwegian research and innovation organisation SINTEF and is also thought to involve a German partner with considerable experience in producing aircraft fuel from organic materials.
WASTE SALMON CRUSHER FOR ISLE OF LEWIS BIOGAS
A multi-crusher supplied by Borger is being used at an award-winning waste-to-energy project in the Outer Hebrides of Scotland. The CREED integrated waste management facility on the Isle of Lewis processes salmon waste into biogas using anaerobic digestion.
The facility manages waste from the island's 22,000 inhabitants and has grown to include a combined heat and power plant (CHP), electric boiler and thermal store, alongside the biogas plant, a wind turbine and a hydrogen system. The IWMF won the Scottish Environment Business Vibes award for its innovative fish waste biogas practices in 2019.
Generating fish waste biogas from salmon waste with a chopper pump. A rotary lobe chopper pump is playing a key role in the continuing success of an award-winning waste-to-energy operation in the Outer Hebrides, Scotland.
At Stornoway's CREED integrated waste management facility (IWMF) on the Isle of Lewis, the Borger Multicrusher chops a 7-cubic-ton batch per shift of coarse waste salmon. This has enabled the facility to integrate fish with household food waste and garden waste for its anaerobic digestion (AD) and biogas process.
Based on the design of the Borger rotary lobe pump, the twin-shaft Multicrusher homogenises the waste salmon to facilitate the pumping and pasteurisation process ensuring that downstream equipment can operate smoothly.
Fish Waste Biogas – Why Everybody Is So Excited About Salmon
The commissioning of a landfill biogas plant comes after three months of on-site commissioning and years of planning.
“This project benefits our customers by not only expanding our availability of renewable natural gas but ensuring that waste is put to good use,”
said Doug Stout, Vice President of external relations and energy efficiency.
“with the successful opening of the salmon farm landfill biogas plant, we're excited to be moving forward with similar projects across the province.
Conclusion to “Fish Waste Biogas”
Harnessing biogas from salmon and other fish waste is an innovative approach that fosters sustainability in the aquaculture sector while also addressing energy security.
Though the technology is promising, further research and development, policy support, and industry collaboration are needed to scale up and realize the full potential of this renewable energy source.
By doing so, we will be one step closer to a circular economy where waste is no longer waste, but a resource paving the way for a more sustainable and secure future.
FAQ: Fish Waste Biogas
1. How can you convert fish waste into biogas?
Fish waste can be converted into biogas through a process called anaerobic digestion. In this process, microorganisms break down organic matter in the absence of oxygen, producing biogas as a byproduct. The fish waste is placed in a sealed container, and as it decomposes, methane-rich biogas is generated.
2. How much of a biogas source may fish waste be?
Fish waste can be a significant biogas source, especially in industries like aquaculture, fish processing, and seafood markets. The amount of biogas generated depends on the quantity of fish waste available for digestion. Large-scale fish farms or processing plants can produce substantial biogas, making it a valuable renewable energy resource.
3. What kind of fish waste will produce biogas?
Various types of fish waste can be used to produce biogas, including fish offal, scales, bones, and other discarded parts from fish processing. Additionally, fish residues from fish markets or expired fish can also be utilized as a biogas feedstock. The key is to have organic matter rich in carbon, which is essential for the anaerobic digestion process.
4. What kind of trash do fish produce?
Fish waste includes various organic materials, such as scales, fins, tails, guts, and bones, which are considered byproducts in fish processing. Additionally, uneaten fish feed and faecal matter from aquaculture operations also contribute to fish waste. Proper management of this waste is crucial to avoid environmental pollution and harness its potential for biogas production.
[Article updated and published on 11 October 2020. Updated and re-published in August 2023.]