Cleaner Fuels4 min read
Why Biogas Is an Eco-Friendly Fuel
Biogas is renewable, burns without smoke, turns waste into energy and leaves fertiliser behind — a genuinely closed loop, not just a cleaner fuel.
Cleaner Fuels
LPG, CNG, biogas, hydrogen and fuel cells — which are genuinely cleaner, by how much, and what the trade-offs are.
Cleanliness in fuels follows one ratio: hydrogen to carbon. The more hydrogen a fuel carries per carbon atom, the more of its energy comes from forming water rather than carbon dioxide. That ratio predicts the entire ranking, from hydrogen at the top through methane, propane, petrol and diesel down to coal — and it means you can place a fuel you have never studied simply by reading its formula.
The section covers the fuels that ranking rewards: LPG and CNG, natural gas, biogas, hydrogen and fuel cells. It also covers where each one's advantage stops. CNG is genuinely cleaner than petrol at the tailpipe, but methane leaking upstream is roughly 80 times more warming than carbon dioxide over twenty years. Hydrogen produces only water when burned, and about 95% of the commercial supply is currently made from natural gas.
Biogas is the one that survives scrutiny best, because its case does not rest on burning cleanly. It rests on capturing methane that would have reached the atmosphere anyway.
What goes wrong most often
- Treating 'cleaner' as 'clean' — none of these except green hydrogen is emission-free.
- Judging hydrogen by its calorific value per kilogram while ignoring its volume.
- Assuming an ODS or clean flame removes the need for ventilation indoors.
- Ignoring upstream methane leakage when comparing gas with coal.
- Confusing biogas with natural gas because both are mostly methane.
8 guides in Cleaner Fuels
Cleaner Fuels4 min read
Fuel Cells: How They Convert Chemical Energy Directly Into Electricity
A fuel cell converts the chemical energy of a fuel directly into electrical energy without combustion, escaping the Carnot limit that caps heat engines.
Cleaner Fuels4 min read
Why Hydrogen Is Not Used as a Fuel Despite Being the Cleanest
It has the highest calorific value and produces only water, yet must be manufactured, stored at 700 bar or −253 °C, and it embrittles metals.
Cleaner Fuels4 min read
Advantages of Using LPG and CNG as Fuels
High calorific value, clean smokeless burning, no ash and instant control — the practical reasons LPG and CNG replaced solid and liquid fuels.
Cleaner Fuels4 min read
Why Natural Gas Is Called a Clean Fuel
It burns almost completely, leaves no ash or soot, contains virtually no sulphur, and emits about half the carbon dioxide of coal.
Cleaner Fuels4 min read
Which Is the Cleanest Fuel? Hydrogen, CNG and What 'Clean' Means
Hydrogen is cleanest because it produces only water. Among fuels in general use, CNG is the least polluting. Here is the full ranking.
Cleaner Fuels4 min read
Is CNG More Polluting Than Petrol? No — Here Are the Numbers
CNG produces less carbon dioxide, carbon monoxide, particulate matter and sulphur than petrol. The statement that CNG is more polluting than petrol is false.
Cleaner Fuels4 min read
Why LPG Is a Better Domestic Fuel Than Wood
LPG gives roughly three times the heat per kilogram, with no smoke or ash — which makes the switch a health intervention, not just convenience.