Biomethaan

Biomethaan, or biomethane, is a form of renewable methane produced from organic matter. It is chemically identical to natural gas and can be used interchangeably in gas networks and as a transportation fuel when upgraded to pipeline quality.

Most biomethane is produced by anaerobic digestion of organic waste streams, such as agricultural residues, manure, sewage sludge, food waste, and the organic fraction of municipal solid waste. Gas produced (biogas) contains methane, carbon dioxide, and trace gases. Upgrading removes CO2 and impurities to reach high methane content, typically around 95% or higher, producing biomethane that meets natural gas pipeline standards. Common upgrading methods include water washing, chemical scrubbing, pressure swing adsorption, and membrane separation.

Alternative production paths include gasification or pyrolysis of lignocellulosic biomass, followed by gas cleaning and methanation, or power-to-gas routes using renewable electricity. Feedstock sustainability, lifecycle greenhouse gas balances, and nutrient management are important considerations. While biomethane can reduce emissions by diverting waste from landfills and displacing fossil methane, the overall impact depends on feedstock, energy used in upgrading, and methane leakage.

Applications include heating and electricity generation, and as a renewable vehicle fuel in compressed natural gas (CNG) or liquefied natural gas (LNG) form, or via injection into natural gas grids. In many regions biomethane is certified as renewable natural gas (RNG) or biomethane with labeling on greenhouse gas savings.

Challenges include securing steady feedstock supply, contamination by siloxanes or sulfur compounds that damage equipment, capital costs for upgrading and grid connection, and regulatory and market barriers. Despite these, biomethane is viewed as a key option in decarbonizing gas supply and transport in several countries, with ongoing policy support and market development.