Using household waste to produce bioethanol can reduce landfill dramatically while producing heat and electricity, Mika Aho, managing director of leading Finnish bioethanol company St1 Biofuels, told EurActiv in an interview.
St1 produces bioethanol from various types of waste and industrial byproducts. Because such feedstock already exists, no incremental CO2 is emitted during production via this method. Moreover, some emissions are prevented, because the waste does not end up as landfill and thus does not generate methane, a "far more dangerous greenhouse gas than CO2," Aho said.
"We have not come across any other methodology that would produce CO2 emissions as low as ours," he stated.
The company uses raw materials like dough and cleaning water from a bakery, as well as residue from a potato flake factory and yeast from a brewery. The next step St1 plans to take is to begin to use separately collected industry and household biowaste in a new plant to be built this year.
"As the feedstock is more heterogeneous, the pre-treatment must be different to make it fermentable. Basically, [...] we use existing technologies but combine them in a unique way," Aho explained.
The first plant to use the unique method will produce about one million litres of ethanol annually, using approximately 20,000 tonnes of waste, Aho estimated. Moreover, the residue left over from the process can be burnt to produce heat and electricity, he said.
The heat can be partially used at source to power the plant itself and the excess can be fed into the district heating network, Aho explained. Alternatively, it could be used by neighbouring industries, he added.
"It is only a short step to using solid municipal waste too. There are technologies where solid household waste can be separated to different segments," Aho said, adding that the amount of waste produced by communties could be reduced to 10-25% according to St1's estimations.
"By integrating different technologies, there are possibilities to - if not close down landfills completely - then reduce the need for them dramatically," Aho stated. Starting from the bottom of the waste hierarchy by effectively separating waste in households and while recycling would guarantee that communities can reduce their waste management problems, he concluded.
The EU promotes biofuels as a sustainable form of energy in its new Renewable Energy Directive (see EurActiv LinksDossier) agreed in December. It obliges the bloc to make sure that 10% of transport fuel is green.
Aho believes the EU targets are helping to create markets for biofuel. Despite this, "as we believe that our technology is economically viable and competitive in a traditional type of market, we think that there would also be market for without these directives," he said.