Scientists at work. Photo credit: Exxon Mobil.

By Anders Lorenzen

Exxon Mobil, one of the largest fossil fuel companies, and one which is under threat from the surge of renewables technology and the electrification of transport has been working hard to find alternatives which would keep their business model alive. The oil and gas company famously came under attack for in the 1970`s hiding and not publishing research conducted by their own scientists, showing that the link between burning fossil fuels and temperature increases. The company is now bullish about developing a biofuel alternative to oil by using algae.

Is the age of algae near?

The company believes that within a few years it would be able to produce around 10,000 barrels of algae biofuel a day. That is of course just a drop in the ocean of the oil it produces daily. But it would nevertheless signal huge progress in mass producing biofuel, that does not compete for space with food growing land. That is because algae can be cultivated on land unsuitable for other purposes, and with water that can’t be used for food production. In addition to using non-arable land and not requiring the use of freshwater, algae could also potentially yield greater volumes of biofuels per acre than other sources. Exxon also highlights, that algae can work as a climate mitigation force, as it consumes CO2. Therefore it would have a much lower emissions footprint than conventional oil. They point to research from MIT which states that if all proves well algal biofuels could have a 50% lower emission than fuel from petroleum.

Key breakthrough

Exxon Mobil and its partner Synthetics Genomics (SGI) announced last year that they had solved one of the key obstacles to the production of algal biofuel. They tweaked a particular gene in a certain species of algae. This resulted in it being able to produce double the amount of fat produced in the wild but at the same speed. That fat can then be made into fuel.

“This key milestone confirms our belief that algae can be incredibly productive as a renewable energy source with a corresponding positive contribution to our environment”, so says Vijay Swarup who is the vice president for research and development at ExxonMobil Research and Engineering Company. He said that it had the potential to lower carbon emissions: “Our work with SGI continues to be an important part of our broader research into lower-emission technologies to reduce the risk of climate change.”

Exxon and SGI are not the only ones who have eyed algae’s big potential. But in the past researchers have been hindered in developing a strain that is high in oil content and also grows quickly. These are the two critical characteristics for scalable and cost-efficient oil production. In the past, the slower growth has negatively affected previous attempts to increase algae oil production volume, and thus many projects have closed down.

However, the ExxonMobil & SGI collaboration has increased the lipid content of algae while decreasing the starch and protein components without inhibiting the algae’s growth.

One of the key objectives for Exxon is that as the world addresses climate change the oil age does not need to end. Energy generation will just not be concentrated on fossil fuels and therefore their existing oil infrastructure can remain in place. Exxon’s algae biofuel could potentially also be refined in their existing oil refineries – producing fuels no different from convenient, energy-dense diesel. Additionally, oil produced from algae also holds promise as a potential feedstock for chemical manufacturing.

Some challenges remain

However, while significant progress has been made challenges remain before the fuel you put into your car is made from algae. These problems will have to be tested in labs before commercial scale is possible. According to the researchers, the main challenge is that algae naturally harvest significantly more light than they can effectively convert to biofuels. With only a fixed amount of light hitting the surface of a pond, the goal is for the algae to use this light as efficiently as possible. Another problem is that the amount of wasted sunlight varies greatly depending on the algae species and growth conditions, but can be as high as 80 percent or more. The researchers are conducting fundamental research to decrease the amount of wasted sunlight and to increase biomass productivity, by improving the photosynthetic efficiency of individual algae cells. In order to achieve this, the SGI team is working to engineer algae cells which will absorb only the amount of light that they can effectively use.

The oil age is not about to end

Swarup adds: “We know certain types of algae produce bio-oils. The challenge is to find and develop algae that can produce bio-oils at scale on a cost-efficient basis.” In order to satisfy even just a small amount of the demand of the US road transportation would require a significant amount of algae.

Exxon believes that algae will just meet the demand that is required as the population grows. And they believe that energy demand will continue to rise and so will emissions; so this should not be seen as them saying goodbye to conventional crude oil. However, the company says they’re committed to researching and exploring low-carbon solutions. And therefore a lot of research is continuing into other technologies such as carbon capture and storage (CCS).