There’s an increasing need for renewable energy around the world. At the same time, there’s a dire need to reduce food waste and all the negative consequences that it provokes.
Fortunately, biogas production is an innovative solution that addresses both concerns. By turning food waste to biogas, businesses can effectively manage waste and meet energy needs in commercial settings, making it a valuable strategy that’s gaining increasing attention.
Keep reading to better understand how to create biogas from food waste, its benefits, and future prospects of biogas production from food waste.
Key Takeaways
- Turning food waste into biogas has a variety of long-term benefits, including landfill diversion, decreased methane emissions, and lower energy costs.
- Biogas production relies on bacteria to break down the organic material in food waste. While this occurs naturally in some environments, large-scale food waste must be treated in a controlled setting known as anaerobic digestion.
- Food waste to biogas conversion typically takes around 10 to 30 days. That said, there are various factors that affect this timeline, such as the type of food waste, the design of the digester, and the operating conditions.
- Biogas production has become an increasingly popular waste management strategy, with high potential in commercial settings. As this industry continues to evolve, we expect to see advances in technology, substantial market growth, and greater integration with other renewable energy systems.
What is Biogas?
The big question is: what is biogas?
Biogas is a renewable energy source produced from organic waste, which typically includes food waste, agricultural waste, manure, sewage, and other biodegradable materials. Biogas consists of methane, carbon dioxide, and trace amounts of other gases and has multiple applications in the energy sector, including fuel, electricity, and heat systems.
Can Biogas Be Generated from Food Waste?
Yes, biogas can be generated from food waste. In fact, biogas generation from food waste has a variety of long-term benefits, including landfill diversion, decreased methane emissions, lower energy costs, and more.
While there are various types of organic waste that can be used for biogas production, food waste is a great option due to its rich organic content and high moisture content.
Even more, the energy potential of biogas production from food waste is huge. The EESI gives us an insight into how this would look, saying that with 100 tons of food waste per day, anaerobic digestion can generate enough energy to power 800 to 1,400 homes each year.
How Does Food Waste to Biogas Work?
With biogas production quickly gaining widespread attention, it’s important to understand how to make biogas from food waste.
In short, this process relies on bacteria to break down the organic material in food waste, resulting in biogas production. While this occurs naturally in some environments, large-scale food waste must be treated in a controlled setting known as anaerobic digestion.
There are various steps that must be taken for this process to be successful, including waste collection, a comprehensive sorting process to eliminate non-organic materials, and various preprocessing techniques, such as adjusting moisture levels to create ideal conditions to turn food waste into biogas.
Anaerobic Digestion
As mentioned, the anaerobic digestion of food waste is a process where microorganisms break down biodegradable matter, such as food waste and other organic waste, in the absence of oxygen. This process involves various stages, including hydrolysis, acidogenesis, acetogenesis, and methanogenesis, each contributing to the breakdown of complex organic materials into simpler compounds.
This process has two valuable byproducts: biogas, a renewable energy source, and digestate, a nutrient-rich byproduct that can be used as fertilizer. Due to its various benefits, such as landfill diversion, nutrient recovery, and renewable energy generation, anaerobic digestion has become a valuable waste management approach.
Methods of Getting Biogas from Food Waste
There are different approaches that businesses can explore when producing biogas from food waste. Whether you’re handling bakery waste, household waste, or other types of organic materials, different technologies are tailored to handle specific types of food waste effectively.
Wet Anaerobic Digestion
Wet anaerobic digestion is a popular approach that’s designed to process waste with a high moisture content, typically containing 5 to 15% solid content. This system enables the material to be pumped and mixed easily, which is ideal for processing liquid-rich food waste like kitchen scraps and food processing residues. The exact ratio of water to waste can vary depending on the specific system and type of organic material being processed.
Dry Anaerobic Digestion
Dry anaerobic digestion, on the other hand, is a great solution for treating waste with high total solid contents, typically containing 15 to 40% solids. The solid waste is usually stacked or arranged in layers, and though not always used, some systems spray leachate over the top to promote the breakdown of waste.
While each process has its own benefits and setbacks, a recent review on dry anaerobic digestion states that when compared to wet AD, dry AD can offer several benefits, including higher volumetric methane yield, smaller reactor volumes, decreased energy requirement for heating, less digested residues, and low moisture in digestate that’s easier to deal with.
Continuous vs. Batch Processing
As explained by the EPA, continuous flow digesters have feedstocks that are constantly fed into the digester while continuously removing digested material.
In batch digesters, the feedstocks are loaded into the digester at once. After loading, there is a set period for digestion, in which it is then manually emptied and reloaded.
So which system is better?
A comparative evaluation of these two processes claim that batch digesters are better suited for the digestion of municipal solid waste for biogas production. Although batch digesters produce about four times less methane per unit volume compared to continuous digesters, they are significantly more cost-effective, making them an attractive option for recycling food scraps.
How Long Does It Take to Produce Biogas from Food Waste?
The production of biogas from food waste typically takes around 10 to 30 days. That said, there are various factors that affect this timeline, such as the type of food waste, the design of the digester, and the operating conditions. In general, food waste with a higher moisture content produces biogas more quickly, while solid food waste may take longer.
How Much Biogas Can Be Produced from Food Waste?
Biogas yield refers to the amount of biogas that can be produced from a specific amount of food waste. The yield depends on the type of food waste and various other factors, including:
- Moisture content: Moisture content enhances the growth of methanogenic bacteria, therefore facilitating their movement and transportation of nutrients. Essentially, this makes the process more efficient, having a positive effect on the overall biogas yield. In general, high-moisture foods like fruits and vegetables produce more biogas than dry foods.
- Nutrient composition: The nutrient composition of waste significantly affects biogas yield from food waste because it determines the availability of key elements like fat, protein, and carbohydrate content.
How much biogas can be produced from 1 kg of food waste?
1 kilogram of dry matter in food waste can produce between 76 and 421 liters of biogas. This wide range is influenced by several factors, including the type of waste, its carbohydrate and fiber content, and additional environmental factors.
What Food Produces the Most Biogas?
A review of biogas production from food waste states that for a better biogas production rate, high carbohydrate and low fat and protein contents are required. The study shows that dates, rice waste, beans, and mixed food waste had the greatest potential for high biogas production.
The sample with the highest fat content, which was fish waste, had the lowest potential for biogas production. Samples with the highest protein content, particularly meat waste, also had a low potential for biogas production.
Benefits of Converting Food Waste to Biogas
There are various benefits of food waste to biogas conversion, including:
- Renewable energy source: In addition to being eco-friendly, using biogas as an energy source can lower energy costs significantly, making it a valuable waste management approach.
- Support for the circular economy: By converting food waste to energy, businesses can reuse organic materials and integrate them into new production cycles, therefore contributing to a circular economy.
- Improved waste management: Biogas production can lead to more efficient management of food waste. In addition to reducing landfill use, this approach minimizes pollution and addresses the issue of food waste producing methane.
- Environmental and sustainability impacts: Biogas production captures methane that would otherwise be released into the atmosphere from landfills, therefore reducing greenhouse gas emissions and helping fight global warming.
- Helps local economies: Building 13,500 biogas systems in the United States could add over 335,000 temporary construction jobs and 23,000 permanent jobs, thereby helping support local economies.
Challenges in Using Food Waste for Biogas Production
While biogas production has an array of benefits, there are also various obstacles that businesses must know how to manage, including:
- Variability in waste composition: Businesses that treat different types of organic materials must know how to handle foods with different nutrient levels and moisture content, as each of these characteristics affects the efficiency of biogas production and leads to inconsistent yields. To overcome this challenge, there are various strategies that businesses can explore, such as implementing more rigorous sorting and preprocessing methods to homogenize the waste before it enters the digester.
- Contamination: Contaminants like plastics, metals, and other non-organic materials can disrupt the anaerobic digestion process by damaging equipment, lowering biogas yields, and increasing maintenance costs. To prevent contamination, businesses can implement strict sorting and pre-treatment processes.
- Collection logistics: There are various logistical challenges involved in collecting and transporting large volumes of food waste from commercial sources to biogas facilities. Issues such as delays in collection and inefficient transportation can lead to spoilage, increased operational costs, and environmental concerns, meaning that having a comprehensive collection system should be a top priority.
Prospects of Biogas Production from Food Waste
Biogas production has become an increasingly popular waste management strategy, with high potential in commercial settings. As this industry continues to evolve, we expect to see advances in technology, substantial market growth, and greater integration with other renewable energy systems.
Technological Advancements
Thanks to recent advances in technologies, businesses and governments can enhance waste management processes and achieve sustainability goals. Emerging technologies, such as improved anaerobic digestion processes and better biogas purification methods, have the potential to enhance the efficiency and scalability of biogas production from food waste, making it more viable for large-scale commercial use.
Market Growth Potential
There’s an increasing market demand for renewable energy, which has had a huge impact on the growth of sustainable technologies. To support this notion, government policies, environmental regulations, and financial incentives are driving the expansion of the biogas industry, with projections showing significant growth in the coming years.
Integration with Renewable Energy Systems
Biogas production can complement other renewable energy sources like solar and wind, providing a more reliable and continuous energy supply. This helps prevent energy supply gaps and enhance grid stability, offering huge advantages to energy providers, businesses, and consumers alike.
The Bottom Line
Transforming food waste into biogas helps divert food from landfills, create a renewable energy source, and support environmental goals, making it a valuable approach in sustainability efforts.
At Shapiro, we understand the importance of reducing large-scale waste, which is why we work closely with our clients to create tailored waste management strategies that work for them.
If you’re interested in learning more about our food waste recycling solutions, contact us today.
Baily Ramsey, an accomplished marketing specialist, brings a unique blend of anthropological insight and marketing finesse to the digital landscape. Specializing in educational content creation, she creates content for various industries, with a particular interest in environmental initiatives.
