Researchers at the Indian Institute of Technology (IIT) Guwahati have devised a cutting-edge biological approach for converting methane and carbon dioxide (CO2) into cleaner biofuels via methanotrophic bacteria.

The novel technique, which addresses two urgent global challenges: the negative environmental impact of greenhouse gases and the depletion of fossil fuel supplies, is a big step toward sustainable energy solutions and climate change mitigation.

Methane, a greenhouse gas that is 27-30 times more strong than CO2, contributes significantly to global warming. While converting methane and CO2 into liquid fuels can help cut emissions and provide renewable energy, current chemical processes are energy-intensive, expensive, and emit toxic byproducts, limiting their scalability.

The team from IIT Guwahati created a wholly biological process that uses Methylosinus trichosporium, a species of methanotrophic bacterium, to convert methane and CO2 into bio-methanol under mild working conditions. Unlike previous chemical processes, this procedure does not require expensive catalysts, produces no harmful byproducts, and uses less energy.

“This research is a breakthrough because it demonstrates that bio-methanol, derived from bacteria feeding on methane and carbon dioxide, can be a viable alternative to fossil fuels,” said Prof. Debasish Das, Department of Biosciences and Bioengineering, IIT Guwahati.

“Unlike conventional biofuels, which rely on crops and compete with food production, our technique use greenhouse gasses, avoiding the ‘food vs. fuel’ dilemma. It is an environmentally and economically viable solution that uses low-cost resources while helping to reduce emissions,” Das said.

The novel two-stage process involves trapping methane to produce bacteria-based biomass, which is then used to convert carbon dioxide into methanol. The researchers refined the process using advanced engineering techniques to improve gas solubility, resulting in much higher methanol yields. The bio-methanol produced was mixed with diesel (5-20% ratio) and tested in a four-stroke diesel engine. The findings, published in the journal Fuel, include a reduction of up to 87% in carbon monoxide, hydrocarbons, hydrogen sulphide, and smoke emissions.

Diesel-methanol mixes surpassed pure diesel in terms of fuel consumption, energy economy, and engine performance, while preserving comparable mechanical efficiency. The researchers stated the approach has enormous potential to decarbonise essential industries such as oil and gas, refineries, and chemical manufacture, opening the way for a more sustainable future.