The New algae alchemists

23 May 2019 |

How an Estonian start-up is using microscopic algae to turn CO2 into valuable products

Liina Joller-Vahter (left), Timo Kikas (right). 

It almost sounds too good to be true. A means to soak up a greenhouse gas from the atmosphere and use it to help the world’s growing population feed itself. That is the promise of a process that could harness the carbon dioxide generated by heavy industry to cultivate microalgae that can then be used to produce feedstock for animals and even food for humans.

A spin off from the University of Tartu, Power Algae is one of several companies trying to mix microalgae alchemy into industrial processes. But the technology developed by Power Algae, branded ALGACAP, differs from its peers in that it is designed to cultivate microalgae right through the harsh winters of Northern Europe, when daylight is in short supply and temperatures are generally below freezing.

These “suboptimal climatic conditions” had threatened to undermine Europe’s competitive position in the fast growing microalgae market, according to a 2014 report by the Joint Research Centre on this sector. Noting Europe’s “outstanding tradition in high-quality agriculture production”, the JRC report recommended public support for research into the use of microalgae as a diversification strategy for food and feed inputs, as the continent tries to mitigate climate change.

“Sequestrating CO2 from flue gas is done in a couple of places using different technologies, but there is no conclusive, dominant design – an optimal solution has not been found,” says Liina Joller-Vahter, CEO of Power Algae and a lecturer at the University of Tartu. “The main challenge is to make it commercially viable.”

Extracting valuable compounds

Launched in 2013 by Joller-Vahter and a fellow doctoral student, Power Algae has developed a process to sequestrate carbon dioxide directly from flue gas and use it to accelerate the growth of microalgae in a prototype photobioreactor deployed in the Estonian University of Life Sciences. Several valuable compounds can be extracted from the microalgae that grow inside these biological filters, which can then be used to produce livestock feed, oils, cosmetics and other products.

The next step for Power Algae is a large-scale pilot in collaboration with an industrial company, which can integrate the new photobioreactor into its chimneys and then grow microalgae in greenhouses next to its production plants. The goal would be both to generate an additional source of revenue and offset the negative environmental impact of the existing industrial process.

Under the European Emission Trading Scheme (ETS), emitters of carbon dioxide have to buy permits, the cost of which varies with the so-called carbon price set by ETS. “The carbon price is definitely part of the economics,” says Joller-Vahter. “But if the biomass could be commercialised to its full potential, then it could be viable without the carbon price.”In future, Power Algae also plans to set up its own algae cultivation operation and offer a “flue gas cleaning service” to third parties.

As it plans the large-scale pilot, Power Algae is in discussions with three potential partners - an oil shale oil producer, a local heat energy producer and a cement company. Which one takes priority may depend on the chemistry: “The characteristics of the flue gas are crucial,” Joller-Vahter explains. “It depends on the percentage of CO2 and other ingredients.”  To raise the 1-2 million euros required to get the large scale pilot up and running, the start-up also plans to tap EU funds, potentially from the Horizon 2020 programme.

Natural algae versus GMO

If this pilot proves the economics will work, commercialisation will be the next step. Professor Timo Kikas of the Estonian University of Life Sciences is optimistic: Tests using a semi-industrial burning process, a heat laboratory and a prototype photobioreactor at the Estonian University of Life Sciences have demonstrated that Power Algae’s solution could be used to grow microalgae inside greenhouses at Estonia’s latitude. “In the past few years, the advances have been considerable: We are now talking about very different reactors from five years ago,” notes Kikas. “Many scientific approaches are looking at using genetic modification, but this has many downsides, not least the issue of social acceptance. But as natural algae can be very effective at carbon capture, we don’t really need to go that way.”

All about algae

The waters of the world, oceans, seas, rivers, creeks, lakes and even ice, host a large variety of organisms which are able to use light as the only energy source for their metabolic processes. Algae are a group of relatively simple, plant-like organisms, most of which are capable of performing photosynthesis: They capture light and use its energy to convert CO2 into sugars and oxygen. In this way, they make a large contribution to global oxygen production (between 50 to 87 per cent). There are 80,000 to 100,000 different algae species with widely varying characteristics; many of which have been investigated. Algae size ranges from micrometres of unicellular micro-algae to macro-algae seaweeds of tens of metres.

Source: Joint Research Centre. Microalgae-based products for the food and feed sector: an outlook for Europe, 2014

To make its process as efficient as possible, Power Algae is using connected sensors that continuously monitor temperature, light levels and other crucial parameters inside its photobioreactor. “In future, the whole process could be automatic,” notes Joller-Vahter. “If you have the sensors, you can create algorithms that automatically optimise the conditions for the species. You can also use triggers when the conditions go above and below certain thresholds to change the heating and the lighting.”

If it does prove commercially viable to grow microalgae in Northern Europe, the region will be competing with existing suppliers from Asia, which tend to use large artificial ponds in fields in the open air. “The challenge for them is that anything in nature can fall in and create contamination, whereas our photobioreactors are much more controlled,” explains Joller-Vahter. “Our method is more expensive, but you are getting a purer product quality, which is key in cosmetics and the food and feed sectors.” Power Algae employs LED lights at a specific wavelength for a set number of hours at a time, dependent on the species of algae being cultivated. The environmental conditions can be tweaked to govern the fat content, the protein content and the pigment content of the algae, depending on the target market.

“It is a growing market because consumers want more products from natural ingredients – there is demand for products from natural sources rather than from the oil industry,” explains Joller-Vahter. Although the production of microalgae in Europe is low (accounting for less than 2% of global production), the commercial value of some species cultivated in the region  (such as Haematococcus pluvialis, which is used in the health food market) can be as high as €125/ml, according to the European Biomass Industry Association.

For more Estonian research related information visit Research in Estonia portal.

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