Sewage set to power commercial-scale algae biofuels

An EU-backed €12M algae biofuel demonstration project which aims to produce commercial-scale energy from sewage is set to go ahead in Spain later this year.

The All-Gas scheme will cultivate fast-growing algae at wastewater treatment plants by recycling nutrient by-products in the sludge that water companies currently have to clean up and dispose of.

To date, much of the work to develop biofuels from algae has been undertaken at a small-scale laboratory level and not proved cost-effective when compared to market fuel prices. All-Gas aims to scale up the technology and demonstrate it on a commercial scale at a 10 hectare site in Chiclana, southern Spain, where an existing wastewater plant is based.

Led by global water operator aqualia, in conjunction with six other EU partners, the project is targeting dry algae production of 3,000kg per day with an expected oil content of 20%. It is expected this will be able to fuel up to 400 fleet vehicles from the combined biodiesel and biomethane outputs.

According to aqualia project leader Frank Rogalla, finding a useful market for the nutrient by-products is a key driver for water companies.

“Nutrients are something we have in abundance in wastewater which we are currently being paid to destroy, and we don’t feel comfortable doing that,” he said.

He added that the technology opportunity was significant. “We have rethought our flow processes for wastewater treatment – turning it into value creation instead of waste production.”

The technology should also deliver a number of other benefits including the removal of nitrogen and phosphorous from wastewater. This will minimise pollutant levels in compliance with EU discharge requirements and reduce waste generation costs.

The project will be implemented in two phases. A prototype facility will be built and operated over the first two years and once proven viable in full-scale algae ponds, 10 hectares will be developed and operated at a commercial scale over the next three years. Findings will be released in 2016.

Maxine Perella

Action inspires action. Stay ahead of the curve with sustainability and energy newsletters from edie