In a basement in North Zealand, a small test set-up is producing the carbon-neutral fuel—methanol. Chemically pure, odourless and burning with a clear blue flame, methanol is almost invisible in daylight. The octane rating for methanol gas is 110. The main ingredients are liquid manure from Lemvig, Denmark, and a westerly wind.
When you have agricultural slurry—which is transformed into biogas—and surplus wind turbine electricity—which is stored as hydrogen—you can produce the synthetic fuel—methanol. This is the experiment being conducted by Professor Per Møller from DTU Mechanical Engineering in his test set-up at the company Elplatek in North Zealand.
Methanol can be poured into the petrol tank and thus help the transport sector transition towards the green conversion and a fossil-fuel independent society.
“The day the oil wells dry up is the day we will be dependent on synthetic fuels. And we must face the fact that we won’t get everyone to buy hydrogen and electric cars, even though they are part of the solution. If you are transporting heavy goods by air, sea or road, hydrogen or batteries simply aren’t the answer,” says Per Møller.
He explains that methanol, which can be made from methane and CO₂ (from biogas production) and hydrogen (from wind power) is an ideal energy source for the private transport sector:
“Methanol is a great car fuel. It has an octane rating of 110 and has been used for a long time in the USA. However, producing methanol from CO2 as we have isn’t as straightforward as it sounds. Nevertheless, we have succeeded,” says Per Møller.
Methanol is relatively simple to refine into so-called DME (dimethyl ether), which can replace diesel fuel—or into liquid fuel such as petrol. Per Møller predicts that biogas plants can develop into actual fuel factories, where the manure suppliers—the farmers—not only receive manure, as is currently the case—but also become self-sufficient in a carbon-neutral fuel. Furthermore, the straw from fields can also be effectively converted into biogas.
The professor is collaborating with Lemvig Biogas Plant in the project Megastore, where research is geared to converting wind energy into methane, which can be stored in the natural gas grid. (See the article “From wind to gas”). Per Møller speculates that this storing of wind energy combined with methanol production will make the farmers who deliver manure to the biogas plants fossil-energy independent.
“Every farm associated with Lemvig Biogas Plant can deliver 100,000 litres of fuel to meet consumer needs—and this is after each farm has received 30,000 litres for its own consumption, mind you. So in the long term, Danish agriculture can operate a closed energy cycle. In other words, farmers can run a completely energy-neutral operation by delivering liquid manure or straw to a biogas plant and get fertilizer and fuel in return.”
By fully expanding biogas plants in Denmark and upgrading the gas via hydrogen from wind energy alone, it should be able to keep approximately 1.5 million cars on the road on renewable energy, assesses Per Møller.