Reversing The Burning Reaction
Due to environmental problems, renewable energy is on the demand. However, one of the major challenges with many sources of renewable energy is that storing the energy produces is yet a problem to be solved. A research team in Finland have developed an interesting procedure that could help overcome this problem.
Photo: Public Herald
The sun provides so much energy that, if collected efficiently, it could easily meet the energy demand of today and tomorrow (read this). However, the problem is that our energy consumption never stops, although the sun does not always shine and the wind does not always blow. For this reason, scientists have tried to come up with solutions on how renewable energy could be stored for later use.
Mirror, mirror on the wall
Which is the best solution of them all? Many feasible solutions have already been proposed and are being tested. For instance, in Norway the energy produced on a sunny day is used to pump water up a hill to be stored behind dams (think potential energy). When the sun stops shining this can then be released to produce hydroelectric power. Many researchers and companies are also trying to look for materials that could help store energy. Here, material science plays a key role.
Thinking in reverse
A research team in Finland has decided to take a slightly different approach, by combining their knowledge in chemistry and biology. In their solution to store energy, they use microbes that can reverse the burning reaction of hydrocarbons, such as methane.
The first step is to produce hydrogen (H2) and oxygen (O2) gas from water (H2O). This process is called electrolysis, and as the name suggests, it requires electricity. So as you probably guessed, this could be produced by solar and wind energy when they are available.
Burn the burn
Hydrogen gas in itself could be used as an energy storage, but storing hydrogen has its challenges as gases tend to fly all over the place, and hydrogen gas not only flies, but it can also explode. For decades, researchers have looked into methods of storing hydrogen and tough there are some potential ways to do so, more development is still needed. The Finnish research team decided to look beyond hydrogen, by finding ways to convert it into methane.
Digging their shovels into the swamps of Finland, the research team managed to find microbes that convert carbon dioxide (CO2) and hydrogen into methane (CH4). Though methane is also a gas, it is not explosive as hydrogen gas is. Furthermore, the infrastructure for transporting methane already exists, as it currently makes up a large proportion of the world’s energy consumption. So even though the process of converting hydrogen to methane comes with a 20% energy-loss, the research team believe that the gained benefits are worth losing some of the energy along the way.
So far an 18-liter reactor has been used for testing the procedure. The next step is to use a 100-liter reactor and then expand to a 1000-liter reactor. At these volumes, the reactor could already be used to store the energy from small solar and wind power plants.
News on this new innovation was first reported by the University of Helsinki press
Sakari Tolppanen is an editor of MyScience. He has a passion for education and sustainable development.