The slime solution


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algae biofuel futureThe main company behind the scheme, Spanish FCC Aqualia, has already produced its first crop of algae that will be processed to get methane, thus creating an alternative approach to the increasingly controversial crop-based transport fuels.

The All-gas biofuel demonstration project will cultivate fast-growing micro-algae by using the nutrients in wastewater and then by further processes, generate biomethane which can be captured and used in transport fuel.

Another motivation behind the scheme is to ease the pressure that land-intensive biofuel crops, such as palm oil, put on output and prices of food crops.




The process

The technology bears much similarity to conventional wastewater treatment plants (WWTP), where pollutants are extracted from wastewater and converted into biomass. The difference with the new technology being that energy for the algae growth will come from sunlight and the algae will be harvested for transformation into biofuels. After anaerobic pre-treatment to maximize biogas production and gain CO2, the wastewater is then further purified by the growing algae. Harvested algae will be processed for the extraction of oils and other valuable by-products, while the remaining algal biomass is transformed into biomethane, CO2 and minerals, together with other residual biomass from wastewater or agriculture.

The project will be implemented in two stages at the Cadiz wastewater treatment plant in Spain. First a prototype facility will be put up to gather the main design parameters for the full-scale plant. Once the viability and sustainability of the concept has been verified in full-scale ponds, 10 hectares will be developed and operated during the following three years.

Biofuels process

The project

The All-Gas project is led by a consortium of seven European partners, with Aqualia, the third-largest private water company in the world, co-ordinating the whole scheme. The other partners are SMEs The Feyecon Group, MTD and Hygear, engineering company BDI – BioEnergy International, and research organisations The Fraunhofer Umsicht Institute and The University of Southampton.

All-gas (algas means algae in Spanish) will demonstrate the full value process chain in cultivating fast-growing micro-algae with simultaneous wastewater nutrient removal, harvesting and processing biomass for oil and other chemical extractions. Included, at the 10-hectare commercial scale, is the downstream algal biofuel production and use for transportation in up to 400 fleet vehicles.

Some €7.1 million of the project’s initial €12-million development funding came from the European Commission’s 7th Framework Program for energy-related projects, geared at Europe’s target that 20% of energy should be produced from renewable sources by 2020. As project officer, Dr. Kyriakis Maniatis highlights, “to help meet the EU’s ambitious renewable energy targets, we are supporting innovative approaches, and algae biofuels are one of the most exciting prospects – the All-Gas project was selected among 20 proposals we received for that topic”.

Algae cars biofuelAnd it surely is exciting. If the target productivity of 3,000 kg of dry algae is reached, enough biodiesel to run about 200 cars could be generated.

The bio-methane production from the anaerobic digestion of raw wastewater and biomass residues should yield an equivalent amount of bio-methane for another 200 cars.


Or, as project leader, Aqualia’s Frank Rogalla, colourfully put it, “We are turning an expensive environmental problem into a sustainable bioenergy source. The opportunity is such, that 60 million people – roughly the size of the UK’s population – would be able to power 1 million vehicles from just flushing their toilet!”.

Sounds good, but there is more. Aqualia lists a number of other benefits of the All-gas project: the removal of pollutants nitrogen and phosphorous from wastewater; recycling resources that cuts the need for polluting petrochemical based fertilizers; the energy harvested from wastewater and its residues which avoids the need for electrical energy necessary for the standard wastewater treatment process and reducing the related carbon emissions. Algae also have many advantages over biofuel crops such as oil palm, sugar cane and canola as they allow higher yields, faster growth, plus additional by-products such as fertilizer, colourants, proteins, enzymes and feedstocks can be obtained from the process. Sounds too good to be true. And,for now, it seems to be too.

Not just there yet

In its August announcement FCC Aqualia has already ruled out some of its earlier ideas as unsustainable. Algae biofuel is not a new idea and others have been trying for some time now. In 2009, Exxon Mobil Corp. said it would invest $600 million to develop algae-based biofuels within a decade. It has already invested more than $100 million but after four years economically viable results are still nowhere in sight. French genome engineering company Cellectis as well has problems proving the effectiveness of its technology to produce biofuel from algae to its partner Total. In June they announced they have six more months to do so.

The theoretical potential of algae-based biofuel is undoubtedly huge and believed by many to be an industry game changer. It could greatly reduce the greenhouse emissions and according to estimates by the US Department of Energy (DOE) it grows and can be harvested so quickly that it can produce some 30 times the amount of fuel per acre as any land crop; can be grown anywhere – on mountains, in deserts etc. – so no farming land needs to be used for its cultivation and since the growing algae remove carbon dioxide from the atmosphere, and the fuel produces a lower level of emissions than fossil fuels, algae fuel is theoretically very close to carbon-neutral.

So DOE recently commissioned a study from the National Research Council on the economic and environmental viability of algae fuel in its current state. The findings say we’re not just there yet. There are hurdles to overcome: the growing process needs to be made more economically viable and environmentally sustainable, NRC says. As Joel Cuello, a member of the NRC committee which conducted the recent study, says, these are largely related issues. “In my opinion, you can’t divorce the two. As a matter of fact, most efforts aiming at lowering the production costs is to make the process more sustainable in terms of energy, water, and nutrient use.”

One way is to find or engineer a sort of algae which excretes the oil, thus eliminating the need for harvesting. Another is to find an efficient way to use wastewater including municipal sewage. And this is exactly what the All-gas project is all about. So assuming everything goes as planned, construction of a 10-hectare plant in Spanish Chiclana, should be completed by 2016.




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