What Is Biogas: All You Need To Know

Biogas is a renewable energy source produced from the decomposition of organic matter in a deoxidized or anaerobic environment. It’s so-called anaerobic digestion that occurs when microorganisms break down materials like food waste, manure, crop residues, and sewage sludge and results in a gas mixture primarily composed of methane (CH₄) and carbon dioxide (CO₂), along with trace amounts of hydrogen sulfide (H₂S), ammonia (NH₃), and other gases.

The most valuable component of biogas is methane, as it is a highly efficient fuel source. The higher the methane content, the more energy-dense the gas becomes, making it an excellent alternative to fossil fuels. In many ways, biogas functions just like conventional natural gas, but with the key advantage of being sustainable and carbon-neutral.

Biogas production happens naturally in environments such as swaps, wetlands, landfills, and the digestive systems of animals. However, controlled biogas production in plants allows for more efficient energy generation while managing waste. These plants collect organic waste and feed biomass in sealed tanks called anaerobic digesters, where the process happens in four stages:

• Hydrolysis breaks complex organic compounds into simpler molecules such as sugars, amino acids, and fatty acids.

• Acidigenesis converts simpler molecules into organic acids, alcohols, hydrogen, and carbon dioxide.

• Acetogenesis further decomposes organic acids into acetic acid, carbon dioxide, and hydrogen.

• Methanogenesis finalizes acetic acid and hydrogen conversion into methane and carbon dioxide, creating biogas.

Once produced, biogas can be collected, processed, and used for energy generation in various commercial, industrial, and private applications.

While methane and carbon dioxide are always the primary biogas components, their proportions in the final formula can vary depending on the sources of biogas and production conditions. Thus, some raw materials, like landfill waste, have lower methane content (40–60%), while others, like food waste or manure, are distinguished by higher methane content (55–75%) and lower amounts of CO₂ and other admixtures accordingly.

Several key factors impact the final biogas composition and energy density:

• Temperature: Higher temperatures increase methane production but require more controlled conditions. An optimal temperature for anaerobic digestion is 35–55°C (95–131°F).

• Retention time: The longer the biomass remains in the digester, the more completely it is broken down, increasing methane yield.

• pH levels: The ideal pH for methanogenesis is between 6.5 and 7.5. Acidic or highly alkaline conditions can slow down biogas production.

• Moisture content: Anaerobic digestion requires a moisture level above 80% to facilitate microbial activity and gas production.

By optimizing these factors, biogas plants can maximize methane output while minimizing contaminants.

By converting organic waste into valuable energy, biogas offers a range of environmental, economic, and social benefits.

Unlike fossil fuels, which are finite and contribute to environmental degradation, biogas is a renewable resource that can be continuously produced as long as organic waste exists.

Instead of letting food scraps, agricultural residues, sewage, and manure decompose in landfills, where they release harmful methane into the atmosphere, biogas plants capture and utilize that methane for energy, reducing waste, preventing pollution, and minimizing bad odors.

By trapping methane from decomposing waste and using it for energy, biogas systems reduce harmful emissions that contribute to climate change. Additionally, biogas combustion produces significantly fewer carbon emissions compared to fossil fuels. It burns cleanly, with minimal smoke.

Since biogas can be generated locally from available biomass, it offers energy independence and security, reducing reliance on imported fossil fuels. For rural areas, small-scale plants can reduce energy costs and save money on fuel expenses, thus supporting local economies.

Biogas is not only clean but also an extremely versatile energy source. So, how does biogas work? The uses of biogas span various sectors, reducing environmental impact without compromising energy efficiency.

Biogas is widely used to generate electricity, making it a valuable resource for powering homes, farms, factories, and even entire communities through:

• Large-scale biogas plants using gas turbines or internal gas combustion engines feeding electricity right into power grids.

• Small-scale digesters providing off-grid power solutions.

• Cogeneration systems producing both electricity and heat.

Traditional fuels like firewood and charcoal contribute to deforestation and indoor air pollution, while biogas burns with a blue, smokeless flame, improving air quality and reducing health risks.

Many homes install small biogas digesters to produce gas from kitchen scraps and animal manure. Factories and food processing plants use biogas for boilers, dryers, and ovens, reducing reliance on fossil fuels. Some cities even use biogas to supply heat to multiple buildings through centralized heating networks.

Biogas can be upgraded to biomethane, a purified form of methane with properties similar to natural gas, and used as fuel for transportation. Compressed biomethane gas is a clean fuel for buses, trucks, and even passenger cars. In contrast, liquefied biomethane is used in heavy-duty vehicles and shipping as a renewable alternative to diesel.

Industries and farms use biogas to power machinery and heat facilities, as well as reduce waste. Turning their own organic waste into energy, businesses lower operational costs and create environmentally friendly production cycles.

A valuable byproduct of biogas production is digestate. Unlike synthetic fertilizers, digestate is packed with essential nutrients like nitrogen, phosphorus, and potassium, improving soil health and promoting sustainable agriculture. Farmers benefit from lower fertilizer costs while maintaining high crop yields.

With advancements in technology, increasing investments in renewable energy, and growing environmental awareness, the future of biogas looks promising, with a strong potential to revolutionize how we generate, store, and use energy.

• With the rising role of hydrogen in clean energy tech, biogas could become a major contributor to the hydrogen economy, serving as a major feedstock for hydrogen production.

• Biogas is a great contributor to achieving global climate goals, particularly in reducing methane emissions and decarbonizing industries.

• By closing the loop on organic waste, biogas perfectly aligns with the circular economy model, where waste is continuously reused, recycled, and transformed into valuable resources.

Many businesses worldwide gravitate toward switching to alternative energy sources to reduce their carbon footprint while maintaining cost-effective operations. However, this requires efficient, high-performance technology that ensures seamless integration and maximum energy output. That is where I-Maximum comes in. Whether you consider biomethane derived from biogas or LPG, we offer state-of-the-art energy solutions built around biomethane mixers or venturi mixers, ensuring efficient combustion and maximum energy yield. We can design, engineer, and install a custom system from scratch or provide an advanced integration option that will bring your existing energy supply system to a new level. We’ll help you tap into a greener future without sacrificing energy efficiency and your business profitability.

With its ability to generate clean energy, reduce waste, combat climate change, and promote economic sustainability, biogas is a key player in the global shift toward a greener future. Investing in biogas not only benefits businesses and communities but also helps create a more resilient and eco-friendly energy system.