What is Biomethane? Exploring Its Benefits and Uses

Derived from organic materials, biomethane is a clean, sustainable form of natural gas. Unlike conventional natural gas, which is extracted from deep underground fossil reserves, biomethane is created through a process that utilizes renewable resources and is part of a natural carbon cycle.

Primarily composed of methane (CH₄), a colorless and odorless gas with high energy potential, both biomethane and natural gas are chemically similar. Both can be injected into natural gas pipelines, used in gas-powered appliances and utilized as fuel for vehicles. This similarity makes biomethane a practical alternative energy source with minimal disruption to existing infrastructure.

At the same time, natural gas and biomethane significantly differ in their origins and environmental impacts.

Natural Gas

• Fossil fuel, extracted from deep underground through drilling and fracking.

• When extracted and burned, natural gas emits carbon dioxide, contributing to global warming.

• Requires additional processing to match biomethane purity.

• Finite energy source.

Biomethane

• Renewable material produced as part of a closed carbon cycle.

• Biomethane production helps reduce overall greenhouse gas emissions.

• High initial level of methane purity.

• Renewable nature.

The process of biomethane production primarily involves anaerobic digestion, a natural breakdown of organic matter in an oxygen-free environment. To better understand how to produce biomethane and how waste is transformed into clean, usable energy, let’s explore the production process step by step:

• Collection of organic waste, including crop waste manure, food waste, sewage sludge, organic industrial waste, etc.

• Pre-treatment of organic waste to ensure the waste is in the optimal state for the digestion stage.

• Anaerobic digestion to let bacteria break down the organic material and produce biogas, a mix of methane, carbon dioxide, and trace gases.

• Biogas upgrading or purification to remove impurities and non-methane components.

• Byproduct management to repurpose nutrient-rich digestate as fertilizer.

A complementary method for the production of biomethane is thermal gasification, which involves heating organic matter at very high temperatures to produce a gas that is then purified to yield biomethane.

What is the difference between biogas and biomethane? First, let's look at what is biogas. Biogas is a raw, unrefined gas mixture produced through the natural process of anaerobic digestion, serving as the base for biomethane. The latter is a renewable natural gas gained through a rigorous purification process to achieve clean, high-quality fuel.

Biomethane is produced by upgrading biogas using such techniques:

• Water scrubbing;

• Pressure swing adsorption;

• Membrane separation;

• Chemical scrubbing.

Composition

• Biogas: 50–70% methane, 30–50% carbon dioxide, and trace gases.

• Biomethane: Over 97% methane, with impurities removed.

Production stage

• Biogas: Direct product of anaerobic digestion.

• Biomethane: Refined and upgraded form of biogas.

Purity

• Biogas: Contains impurities like CO₂, H₂S, and water vapor.

• Biomethane: Free of impurities; high methane content.

Uses

• Biogas uses: Heating, and electricity generation in local setups requiring minimum processing.

• Biomethane uses: Natural gas grid injection, vehicle fuel, industrial use.

Infrastructure needs

• Biogas: Used near production sites, not suitable for existing natural gas pipelines.

• Biomethane: Compatible with existing natural gas infrastructure.

Environmental impact

• Biogas: Helps reduce organic waste and methane gas emissions.

• Biomethane: Minimizes greenhouse gas emissions.

While biogas and biomethane share a common origin, their differences lie in composition, processing, and applications. At the same time, both contribute to a cleaner, greener energy future.

With a methane content of over 97%, biomethane is comparable in quality and performance to conventional natural gas, thus allowing for wide-ranging applications. So, how does biomethane work? Let’s look into its versatile uses in more detail.

When injected into the natural gas grid, biomethane seamlessly blends with conventional gas for heating homes, offices, and commercial buildings. Likewise, it is an excellent fuel for electricity generation to power gas turbines, engine generators, and combined heat and power (CHP) systems for communities and industries alike.

Biomethane is increasingly used as a renewable fuel for vehicles, especially in the form of CNG or LNG. When compressed or liquefied, biomethane serves as a clean-burning fuel for public transport, trucks and freight vehicles, and passenger autos, thus decarbonizing the transportation sector.

Many industries rely on high-temperature processes fueled by natural gas. Biomethane can replace natural gas in industrial settings.

• Power boilers and kilns in sectors such as cement, steel, and ceramics;

• Support chemical manufacturing;

• Provide energy for food processing.

Using biomethane on farms creates a closed-loop system, where agricultural waste generates energy to arm equipment, greenhouses, and irrigation systems while producing nutrient-rich digestate as a byproduct for use as soil fertilizer.

Unlike solar or wind power, which depends on weather conditions, biomethane offers a consistent energy supply for backup power systems and emergency generators. Similar to a propane air mixer, biomethane-based installation is ideal for:

• Hospitals, data centers, and critical infrastructure requiring uninterrupted power;

• Remote or off-grid locations where other renewable energy sources are unavailable or insufficient.

Pros

• Renewable and sustainable energy source, making use of organic waste that would otherwise come to landfills.

• Reducing greenhouse gas emissions through production capturing methane.

• Carbon neutral producing CO₂ which is part of the natural carbon cycle, as it was originally absorbed by plants used in the feedstock.

• Versatile applications meeting various energy demands.

• Energy security enhancement thanks to biomethane production, minimizing reliance on imported fossil fuels.

Cons

• Higher initial investment costs to set up biomethane production facilities.

• Limited feedstock availability in some regions.

• Energy-intensive purification process, requiring advanced technologies and significant energy input.

• Temperature-sensitive production limiting biogas production facilities in cold climates.

• Unpleasant odor emissions during anaerobic digestion, restricting biomethane facilities in urban areas.

Biomethane plays a key role in transitioning to a greener, more sustainable energy landscape by providing a more eco-friendly alternative to fossil fuels and reducing dependence on non-renewable energy sources.

With advanced biomethane enrichment systems from I-Maximum, you can embrace the power of biomethane today. We design, engineer, and produce highly precise and efficient industrial gas installations fit for blending up various types of fuels, including biomethane, to produce mixtures with optimal heating value for industrial use. With your individual enterprise needs and goals, we offer customized solutions built around advanced tech, high ROI, sustainability, and scalability.

Don’t hesitate to contact us and get prepared for a more efficient and energy-wise future. 

The primary appeal of biomethane gas lies in its ability to support both energy needs and environmental goals. By converting waste products into a usable energy source, biomethane production contributes to a more circular economy, where resources are reused rather than discarded.