Algae oil is a biofuel derived from algae, offering a renewable and potentially sustainable alternative to fossil fuels. This biofuel can be used in various applications, from transportation to power generation, and has the potential to significantly reduce greenhouse gas emissions.
Algae oil is also known als algal oil and seaweed oil, although the term seaweed oil has gradually become more associated with nutritional supplements (for human consumption) derived from algae than the algal oil used for biofuel.
What is algae oil?
Algae oil is extracted from certain species of algae capable of producing high levels of lipids (fats) which can be converted into biodiesel.
Algae are photosynthetic organisms that can grow in various environments, including freshwater, saltwater, and brackish waters. Certain algae can be grown in wastewater, turning this type of water into something productive for the biofuel sector.
There are two main types of algae:
- Microalgae, which are microscopic. The ones selected for biodiesel production have a high oil content.
- Macroalgae, or seaweed, which generally have less oil but can be used in other biofuel processes like bioethanol production.
Applications
Algae oil has several applications. In transportation, it can be processed into biodiesel for use in diesel engines with little or no modification. Research is ongoing into using algae-derived biofuels for aviation, offering a potential sustainable alternative to conventional jet fuel. In power generation, algae oil can be used to generate electricity, either directly or by co-firing with other fuels.
The residual biomass after oil extraction can be processed into animal feed, providing additional revenue streams.
Production
Commercial algae cultivation for biodiesel production will normally take place in open ponds or photobioreactors.
- Open ponds are large outdoor ponds that mimic natural algae habitats, offering low-cost production but with potential contamination issues.
- Photobioreactors are closed systems that provide a controlled environment for algae growth, increasing efficiency and yield but at a higher cost.
Harvesting and processing
Harvesting and processing involves techniques such as centrifugation, flocculation, or filtration to separate algae biomass from the growth medium.
Oil extraction from the algae is done using mechanical methods, chemical solvents, or supercritical fluid extraction.
Finally, the lipids are converted into biodiesel through a process called transesterification, which involves reacting the lipids with an alcohol (usually methanol) in the presence of a catalyst.
Advantages of algae oil
Algae oil offers several advantages.
It is renewable and sustainable. The environmental benefits include potential carbon neutrality, as algae absorb carbon dioxide during photosynthesis, offsetting the CO2 emissions produced when the biofuel is burned. It is also efficient due to the fast growth of algae, with some species doubling their biomass in just a few hours.
Algae can be cultivated on non-arable land and in brackish or wastewater, reducing competition with agricultural land and water resources. Algae grown in wastewater can help clean the water by absorbing nutrients and heavy metals.
Furthermore, algae have a high oil content, with some species containing up to 60% oil by dry weight, leading to higher biodiesel yields per acre compared to traditional biofuel crops.
Challenges and considerations
Despite its potential, algae oil faces significant challenges. High production costs are a major barrier, with substantial initial investments required for cultivation and processing infrastructure. The energy required for harvesting and processing can also be high, impacting the overall energy balance and economic viability. Technological barriers include scaling up production from pilot to commercial scale and identifying algae strains that are high-yielding and resilient to environmental conditions. Additionally, large-scale algae cultivation requires substantial water resources, which must be managed sustainably, and the impact on local ecosystems and biodiversity needs careful consideration.
One of the research companies that used to be partly funded by ExxonMobil until late 2022 was Viridos, where scientists were trying to genetically modify algae to maximize lipid production. The goal was to create algal strains capable of producing 15 grams of oil per square meter outdoors, and one of Viridos strains had come as close as 10 grams. As ExxonMobil stopped funding Viridos in late 2022, the company was forced to lay off 60% of its workforce. But all is not bleak; a few months later Viridos announced a $25 million round of funding led by Bill Gate´s Breakthrough Energy, and with contributions from companies such as United Airlines and Chevron. So, it looks like the big oil company Chevron has not completely left algae biofuel behind.
The future
Algae oil represents a promising biofuel with the potential to contribute significantly to renewable energy solutions. While there are challenges to overcome, ongoing research and technological advancements are paving the way for its commercial viability. With its high yield, environmental benefits, and versatility, algae oil could play a crucial role in the transition to a more sustainable energy future.
Advances in genetic engineering may lead to algae strains with enhanced oil production and resilience to environmental stressors. Improving the efficiency of cultivation, harvesting, and extraction processes will be key to reducing costs and increasing yield. Government policies and subsidies can help offset initial costs and encourage investment in algae biofuel technology. Collaboration between research institutions, private companies, and government agencies can accelerate development and commercialization.
In this context, it should be noted that a lot of research money had vanished from the algal oil field in the last decade, as big oil companies has stopped their funding.
Several big oil firms used to toute algae-derived oil as a solution to combat climate change, but as of 2024 none of the big oil firms are funding algae biofuel research and development on a major scale. The last one to pull the plug was ExxonMobil, who stopped investing in algae biofuels in December 2022. One of the reasons behind ExxonMobil´s departure might be how a lot of transportation is becoming electrified instead of running on liquid fuels, a trend that is expected to strengten in the near future.
The algae biofuel research used to be at the front and centre of ExxonMobil´s marketing for years, and they did stay in the field for a long time after all their competitors had dropped out. During a period of 12 years, they invested $350 million in algae biofuel. This is a lot of money, but still less than the $600 million they promised to invest back in 2009.
Examples of other big oil companies that used to put a lot of dollars into algae biofuel research but are not longer doing so are BP and Shell. Beginning in 2008, they both announced their serious commitment to the future of algae fuels. Then, the fracking boom busted in the mid-2010s, and they both essentially dropped out of the algal fuel sphere.