Cleaning Air and Water with Euglena

Businesses that use euglena not only as a raw material for fuel and food but also to absorb carbon dioxide and improve water quality, are attracting attention.

Carbon dioxide treatment

Carbon dioxide treatment methods

Under the Paris Agreement, which has been ratified by about 190 countries and regions, the goal is to reduce greenhouse gas emissions to virtually zero worldwide by 2075, or 2050 if possible. On the other hand, the world's energy consumption continues to increase year by year, and it is important to solve this problem as soon as possible.

There are many ways to treat carbon dioxide. One method is to treat the exhaust from thermal power plants, steel mills, cement plants, etc., to increase the concentration of carbon dioxide, and then pump it into underground aquifers or highly absorbent lime layers. In this method, the carbon dioxide reacts with minerals in the ground when it rises to the surface to form carbonates, which are not released back to the ground. Instead of pumping carbon dioxide into the ground, technology has also been developed to extract methane.

Another method is dissolving carbon dioxide in seawater or storing it in liquid form in the deep sea, where it is at low temperature and high pressure, and these methods are called ocean storage.

Another method is to react with a calcium hydroxide solution to produce calcium carbonate. However, this method is not practical because of the cost and the fact that it requires a lot of energy to process.

Since euglena requires carbon dioxide for cultivation, a euglena cultivation plant is also a carbon dioxide reuse plant. Therefore, it is thought that euglena cultivation plants could be used to process the carbon dioxide emitted.

However, since there is a limit to the amount that can be treated in a euglena cultivation plant, the most realistic methods are underground storage and ocean storage, which can treat large amounts, and using euglena in combination with other treatment methods.

Unique Advantages of Euglena

It is possible to treat carbon dioxide using other methods of biomass processing, such as using crops. However, this method does not directly use the exhaust air from plants. This is because plants do not take in as much carbon dioxide as they would if air with a high carbon dioxide concentration were pumped into them. In contrast, algae such as euglena can be cultivated more efficiently by regulating the amount of carbon dioxide emitted into the culture pool, and will grow faster as carbon dioxide is pumped in.

However, if too much carbon dioxide is pumped into the water, the water in the culture pool will become acidic. This is not an environment in which algae can grow. However, euglena is highly resistant to acidity, which other algae are not, and can grow even in water with a high concentration of 15-16%. This means that it can be used if it is treated for soot, denitrification, and desulfurization, even though the concentration is higher than that of thermal power plant exhaust.

Current Status of Utilization

In 2009, Euglena, a company engaged in euglena business, and The Okinawa Electric Power Company jointly conducted a demonstration at the Kin Thermal Power Plant, in which exhaust gas from the coal-fired thermal power plant was fed into the euglena cultivation pool. As a result, it was found that it was possible to cultivate euglena without killing it due to nitrogen oxides, sulfur oxides, and other components.

In 2019, Euglena and ITOCHU Corporation announced and signed a memorandum to establish a culture facility adjacent to a thermal power plant in Indonesia to demonstrate the cultivation of euglena using carbon dioxide and exhaust heat emitted from the thermal power plant.

We think that as governments take stronger action to protect the environment, businesses such as carbon emissions trading will be developed.

Improving Water Quality with Euglena

It is thought that euglena may also help improve water quality.

Sewage contains nutrients such as nitrogen and phosphorus, and when it flows into the ocean, it causes eutrophication, which leads to a massive outbreak of plankton and red tides. It is thought that euglena, along with other zooplankton, can be used to solve these problems.

It is also thought that euglena may be useful in purifying oil-laden groundwater and oil-field associated water that is pumped up during oil extraction.