By ItsNotMagicItsScience

It takes millions of years to make natural gas. But there are other gases we can grow to make our supplies go further.

Everyone knows that you can’t make more fossil fuels. There is a limited supply of them and it’s up to us to find ways to manage them efficiently and make them last for the generations of people that will come after us. Of course, this leaves us with some big questions: how do we manage them and stretch them out?

First of all you have to know how fossil fuels are made to understand why we can’t simply make more of them. We call them fossil fuels because they’re a bit like the dinosaurs bones we sometimes visit in museums. Oil, coal and, of course, gas are the prehistoric remains of fallen trees, rotten vegetation, dead animals and all sorts of other organic materials.

Over time, layers of earth, sand and silt formed on top of this prehistoric organic stew. Layers which eventually solidified into rock. Even more layers of sand and silt formed on top of this rock base, which put enormous pressure on the organic material below it and caused the temperature in these trapped caverns to rise. Over millions of years, this heat and pressure turned the material into the oil, coal and gas we use for fuel today.

But just because you can’t put the same ingredients together and make it in a factory, doesn’t mean you can’t make it go much further. Advances in technology mean that we can produce gas and other fossil fuels more efficiently and with less waste. And as we become more energy aware, our homes, schools, businesses, cars and even the computers and other gadgets we use everyday are becoming more energy efficient as well, needing less gas or other fuel to power them.

So, how else can we make gas go further? Natural gas is mostly made up of the gas methane, along with smaller amounts of gases like ethane, butane and propane. And it’s very pure. This purity is what helps to make it the cleanest fossil fuel: it burns with very few emissions. But natural gas isn’t the only source of methane. When many organic compounds break down they produce substances that we can also use as fuels, like biogas, a mixture of methane with carbon dioxide and some other elements.

While methane in the form of natural gas has no smell (the gas that comes into our homes has a chemical added so that we can smell it in case of leaks), biogas can be quite smelly. This is because of the presence of gases like hydrogen sulphide, which gives it that funky whiff of rotten eggs. Of course, the smell seems more obvious when you remember where it comes from: most of our biogas comes from the fun stuff; household rubbish, sewage, manure and some plant and even the remains of farmcrops.

But that also means we have a lot of it, and we’re making more every day. And these waste products, if they’re left to break down and decay on their own, can be a significant environmental polluter because wasted methane, like carbon dioxide is a greenhouse gas that can trap heat unless we can use it in more practical ways.

Luckily, much of this waste can be treated in giant processing plants and made into forms of methane that we can use. This is an amazing process called anaerobic digestion. The waste is fed into giant airtight tanks and are then treated with bacteria that help to break it up into different compounds, and it’s a natural process that yields the biogas and a bacteria rich sludge that is great as fertilizer.

And because the technology involved is relatively simple, and it happens naturally inside the tanks when you introduce these bacterial agents, countries like China have started to install them in small or remote towns or villages as a way of meeting energy needs in areas where there is limited energy transport and storage infrastructure.

Of course, biogas on its own is not a replacement for natural gas, but when it’s processed further to make biomethane, it can then be combined with natural gas without upsetting the properties of that fuel that make it so efficient and clean burning.

By combining the gases and being careful about the ways we use the fuel, we can significantly reduce the amount of natural gas we use on a daily basis, and that will allow us to make sure there is enough natural gas for everyone for many years to come.