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Transforming Waste into Renewable Energy

Air Liquide biomethane production unit in Walnut, Mississippi

Each day, human activity produces over 10 billion kilos of waste around the world. At a time when the energy transition is a key concern of governments, society and industry, Air Liquide is recycling organic material from farming or from household or industrial waste to convert it into biomethane, a clean and renewable alternative energy source. Air Liquide’s strength relies on its ability to operate across the entire biomethane value chain, especially in Europe and the United States, where the Group inaugurated its largest production facility in the country.

Walnut, Air Liquide’s largest facility in the United States

While in Europe biomethane comes mainly from farming biomass, the situation in the United States is different, where it is produced mainly by landfills. To gain a foothold in this immense market, Air Liquide decided to invest in a biomethane production unit in Walnut, Mississippi. The unit was opened in April 2018. Fully designed, implemented and operated by Air Liquide, it receives 350,000 metric tons of waste yearly, allowing it to inject biomethane into the network to heat around 4,500 homes. A 6.5 km pipeline was built by the Group to connect the production unit back to the energy grid, thus illustrating Air Liquide’s ability to control the entire value chain, from biomethane production to its distribution in natural gas networks.

From clean fuel to carbon-free hydrogen: the potential of biomethane

Aware of the potential of biomethane, Air Liquide has become a key player in the market.

Today, the Group develops technologies dedicated to converting biogas into biomethane

for three main uses: the production of clean fuel, domestic use as a substitute for natural gas, and carbon-free hydrogen production (without CO2 emissions). In 2018 the Group has doubled its production capacity. By the end of the same year, Air Liquide counted twelve units in operation.

Control over the entire value chain

Thanks to its know-how in gases, Air Liquide has developed expertise covering the entire biomethane value chain: from investment in methanisation projects and their operation, to purification using its membrane technology, liquefaction for its transport and storage, and lastly its distribution for various purposes such as bio-NGV stations for clean transport, domestic use as a substitute for natural gas and carbon-free hydrogen production. Depending on the country, the Group recycles various types of sources: primarily agricultural in Europe and from household or industrial waste in the United States. The recycling method also varies: whereas in the United States the phenomenon of methanisation takes place spontaneously in landfills, in Europe it is artificially provoked in digesters (also known as methanisers).

Did you know?

Biogas and biomethane are two different gases, the latter produced by the former. Made up of around 55% methane and 35% CO2, biogas comes from the methanisation of biomass, meaning the fermentation of waste (farm, household or industrial) without oxygen. For use as a fuel or injected into natural gas networks, biogas is purified to become biomethane. The CO2 and other compounds are eliminated, keeping just the methane.

Transforming Waste Key Figures


bio-NGV/NGV (Natural Gas for Vehicles) stations in Europe

x 2

Air Liquide doubled its biomethane production capacity in 2018

~100 M €

invested by Air Liquide in biomethane production in the last 4 years