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.
Mika Aho is the managing director of St1 Biofuels, the only Finnish producer of bioethanol fuel for transport.
St1 Biofuels produces ethanol with an award-winning method. How does this process work?
Basically, we use different types of waste and sidestream from the food industry as feedstock. As this feedstock already exists – it comes from a factory – there is no need to produce it separately. In practice this means that no incremental energy or emissions are needed in the production of the feedstock itself. There we have great savings compared to the traditional methods.
Also, when we take the feedstock, which is a sidestream from the industry, for our use, the alternative use in the worst case could be for example that it would be delivered to landfills or composts. Some CO2 emissions are typically generated in composts. If it ends up in a landfill, it can generate methane, which is a far more dangerous greenhouse gas than CO2, for example.
You claim to produce the world’s cleanest ethanol. What makes your method greener than others?
It’s fair to qualify [this, in] that we are basing the statement of clean ethanol on a study prepared by WSP, which is an international consulting company. The study was conducted in 2006 and states that the ethanol produced with a lifecycle approach is very clean. We have not come across any other methodology that would produce as low CO2 emissions as ours.
Could you give some examples of the sort of raw material you can use?
Today, we have three existing plants in Finland. In those plants, we use for example dough from a bakery and cleaning water from a bakery which still contain some starch.
We will also use residues from a potato flake factory and yeast from a brewery, for example. Basically, when something goes wrong with the product in the brewery, if it contains too much sugar for example, we can use it as feedstock and so it doesn’t have to be disposed of.
So there are examples of different residues. We’re also in some cases using residues from sweets factories.
Where is your ethanol used?
The ethanol content of the product is brought to 85% in our Ethanolix® unit. At that stage, it will be delivered to a centralised dehydration unit. What it basically means is that we have a unit in the port of Hamina where the remaining 15% of water is removed from the mixture.
Through that process we get an end product, which is 99.8% ethanol, so called fuel grade, which can then be blended into gasoline, used as transportation fuel.
You are currently planning the first plant using a new technology, Bionolix™, to be up and running by the end of the year in Finland. How does this differ from existing methods of producing ethanol?
The core technology is the same. So there is an enzymatic treatment of the feedstock and fermentation, and then evaporation and distillation to bring it up to 85% ethanol. That is very traditional.
Now, what is different is that the feedstock we use is separately collected biowaste. It can come from households or industry or from the commercial sector. As the feedstock is more heterogeneous, the pre-treatment must be different to make it fermentable.
Basically, in a Bionolix plant we are using the existing technologies but combining them in a unique way.
The residue we get from the process is a solid fuel that can be burnt to produce heat and electricity.
What is the capacity of this plant?
The ethanol we plan to produce at the first plant is about one million litres per year, electricity 8,000 MWh and heat 17,600 MWh. We will need approximately 20,000 tonnes of feedstock every year to produce that amount of ethanol.
Is the heat and electricity going to be used locally or transported?
First of all, to be able to build this plant, we need to have electricity. We therefore have the electricity grid in front of us. So the electricity we produce can be transferred to the national grid.
For the heat, it can be used partially for our process needs. The excess heat can be fed into the district heating network, if it happens to be close enough. Alternatively, if there is a need for the heat from some other industry in the neighbourhood, it can be used there. So there are different options for the heat that we generate.
Is this technology commercially viable?
Yes, we think so. At least our calculations indicate that. We have based these on the assumption that we would receive the normal market prices, whether that is of ethanol, electricity or heat.
Urban areas are a major source of emissions, and accelerating urbanisation creates increasing waste management problems. Could this be a method through which individual cities could both recycle their waste and satisfy their energy demand?
If we start from the beginning of what we call a waste hierarchy, the separation of waste in the households and in the source of origin is very important. Then recycling all those materials is key to reducing the amount of waste.
Now, what you have left after all that, be it solid municipal waste or biowaste: in our Bionolix plant we can treat the biowaste, reducing the amount significantly. Actually, we can use all of it either to produce ethanol or to create this solid fuel for heat and electricity purposes.
Then there is only a short step to using also solid municipal waste. There are technologies where basically solid household waste can be separated into different segment. There is still some 20 to 30% of biowaste included in solid household waste.
There are existing technologies, which can separate for example SRF, solid recycled fuel, from the waste. It’s basically fibres and cellulosic materials and plastics. They can be incinerated to produce heat and electricity.
We don’t have these technologies in our house, but we can pretty easily integrate them into the Bionolix process. By doing so, the amount of waste can be reduced dramatically.
We estimate that we can reduce that to 10-25% of the original amount of solid community waste. However, this is still an estimation at this stage because we don’t yet have the plant up and running.
By integrating different technologies, there are possibilities to, if not close down landfills completely, to reduce the need for them dramatically.
So you see a big market for this type of biofuel production?
In Finland, we have estimated that there would be capacity for approximately 10-15 Bionolix sites.
We have not done the mathematics for the rest of the world, but all of the western world and much of the developing world are creating significant amounts of waste and obviously the market is huge in that sense.
The EU promotes biofuels in its new renewable energies directive agreed in December. How do you see this new legislation impacting on your industry?
I think it’s very good that these topics are addressed. The demand for biofuel that needs to be in place from the energy context is basically creating a market for our production method. In that sense it is very important that these objectives are put in place, accepted and adopted in the legislation.
Having said all that, as we believe that our technology is economically viable and competitive in a traditional type of market, we think that there would also be a market for without these directives.
The directives are good in the sense that they put pressure, creating market to develop solutions to the challenge that we have. Not only us, but the whole world.
In EU negotiations on the Renewables Directive, concerns were raised over the impact of indirect land use on biofuel production, raising food prices and exacerbating biodiversity loss. Do you think these concerns are legitimate?
I think the concerns are very much legitimate. It’s a very complex area, which is obvious from all the debate around the topic.
At St1, we have not formulated a clear opinion on what the correct approach to this is as we concentrate on sidestream and waste feedstock. But I think that we have a clear philosophy that we want to stay out of the food chain. We believe that there are enough experts in the area who can set up objective criteria to what is considered to be within and out of the food chain.
But in St1’s operations, we really haven’t come across this problem because we already are out of the food chain.
Does that mean that you consider your ethanol as a third-generation biofuel?
That’s a good question. This is at least a second generation. We want to believe that it is even third generation. But I really haven’t seen exact criteria for that.