Can Algae Power Our Cars In The Future?
There is a 100% chance that people will not always be able to go to petrol stations and fill up the tank with fossil fuel. There are two main reasons for this. The first is that fossil fuels are a finite resource that will run out at some point in time. Secondly, they are not environmentally sustainable and have been known to cause problems like air pollution, climate change and oil spills. There is a huge need for alternative fuels, and fortunately, scientists have made significant progress in their research.
Algae has been making waves as the alternative biofuel wunderkind for a while now, and understandably so. It is used for far more than just vegan baking. Found in wastewater, algae is capable of powering jets. Microalgae is made up of microscopic organisms that can photosynthesise like green plants. The single-celled organisms are capable of converting sunlight to energy, and carbon dioxide emitted by power plants to oxygen.
The real allure of algae is that it can be used to power jets and cars. It produces oils that scientists can convert to fuel for cars, planes and trucks. Because it is carbon neutral, algae is better for the environment. It is also renewable and as such, can be used as a source of fuel forever.
Is algae fuel a viable option?
Algae has long been considered a better source of fuel compared to fossils. This is because unlike other natural fuel sources like wheat and soybeans, algae can produce up to 100 times more oil per acre.
As for whether it is a viable option to crude oil, certainly. It should be noted that its long-term viability depends on the petrol pump prices. The cost of petroleum has increased considerably over the past few decades. On the other hand, cultivating, extracting and refining algae oil is getting cheaper. Despite being considered a viable fuel source decades ago, it wasn’t until recently that algae could be produced on a large enough scale to affect national petroleum consumption significantly.
In 2008, Carbon Trust (UK) launched a 26 million pound project to develop algae fuels and make them a commercial reality by 2020. This came at a time when petroleum prices had skyrocketed significantly, making algae a cost-attractive alternative. The cost of making algae-based fuel is expected to drop as research progresses. Efforts have been made to come up with more efficient ways of producing and extracting algae oil.
The United States government invested in multimillion-dollar programs in the 1980s. They were put to an end because no one found a way to make it commercially viable. Japan also conducted some research and efforts stalled when she couldn’t find a way to scale algae production in photobioreactors. These were closed vessels that had plenty of sunlight and conditions to intensify the growth of microorganisms. Such a system that’s capable of scaling algae growth has not made it to the market yet.
It’s not just UK, US and Japan governments that have invested in algae-based fuel. Multiple companies around the world have also made some efforts. Sapphire Energy, a San Diego based company, is particularly notable. The firm has been exploring the option of extracting green crude from a chemical mixture it produces. UK’s Wellcome Trust is one of the major investors in this project.
All things considered, algae is an effective way to harvest solar energy and eradicate fuel crises. It reproduces itself and can grow in areas not suitable for other crops. Algae don’t consume much water and as such, doesn’t add to the global shortage of water.
What would be the environmental impact?
Aquatic impact of algae-based fuel
The quality of water required to grow microalgae varies depending on the strain. Wastewater and sewage, which are abundant in developing countries, can be used. Using industrial and domestic wastewater for production of algae to mass produce algae could help with wastewater remediation.
Biodiversity impact of algae-based fuel
Producing algae oil on a large process is what some would call a controlled eutrophication process. Adequate air supply, as well as regular harvesting, is crucial to ensure continued and efficient production. The downside is that eutrophication is one of the biggest risks to biodiversity. This is because decomposition of algae biomass requires oxygen, which causes asphyxiation of aquatic organisms. It also leads to water toxicity, hypoxia and turbidity.
Terrestrial impact of algae
Production of biofuel is shrouded in controversy regarding how it displaces food crops. One of the key advantages offered by algae is that it has increased growth rate and better yield per unit area compared to terrestrial crops.
Terrestrial diversity impact
Constructing ponds would destroy habitats, hence displacing local flora and fauna. Like large water projects, production of algae could lead to loss of individual animal and insect species, loss of ancient plant species, disturbance of ecological balances and destruction of habitats.
Atmospheric impact of algae fuel
Large scale production of algae also poses a variety of impacts on the atmosphere. However, the amount of impact depends on the scale of algae cultivation. Producing algae on a large scale could enhance biological fixation of carbon dioxide, thus removing large quantities of it from the atmosphere.
Limited research on emissions of other gases has been done. Methane is a potent greenhouse gas, and if emitted in large scale, concerns in the context of global warming and climate change arise. Anaerobic decomposition due to methanogenic bacteria leads to the production of methane. The constant aeration of water during production of algae would hinder methane gas production.
Advantages of algae fuel
The promise of high content energy
Studies have shown that algae are capable of producing up to 100 times more energy per unit area compared to other biofuels. According to the US Department of Energy, producing algae fuel to power the United States would require 14,000 square kilometres. This equates to 14% less than the area used to grow corn.
Uses up a lot of carbon dioxide
A significant benefit of producing algae fuel is that it uses up carbon dioxide. This means a considerable reduction of a gas that causes climate change.
A basic resource that reproduces quickly
Algae only need sunlight, water and carbon dioxide to thrive. These are widely available throughout the world. It can also grow in wastewater and some varieties can even tolerate seawater.
Sustainable source of fuel
Unlike fossil resources that are bound to run out, algae is an infinite source of fuel. This is because it does not compete for resources with other land crops. It can grow for a long time with resources that won’t run out. Even better is that algae fuel is renewable.
Algae can grow in the harshest environments, whether closed or semi-closed systems. It can thrive in any geographical location provided that sunlight and water are available.
Disadvantages of algae fuel
Lots of work still needs to be done on production
Research has made a lot of strides in the production of algae fuel, but there is still a lot of work to do. This is particularly true in the areas of low yields and oil extraction. Artificial dryers use up more electricity and produce little energy. Wet extraction, whilst a promising prospect, needs more research before it becomes a commercial reality.
Requires plenty of money
Algae production is still very expensive, hence why it’s not yet commercially viable. Companies continue to experiment on different ways to mass produce algae fuel at reasonable costs. Whilst the systems used for production are relatively cheap, they have some flaws that need fixing. These include the risk of contamination by native algae species, a low energy density of oil and viral infection. A cheap source of sterile carbon dioxide for use with closed-loop systems is needed. Whilst more effective, bioreactors are very expensive in terms of maintenance and operations.
How Algae Fuel Production Works
Production of algal fuel starts at cultivation. Algae can thrive in almost any conditions, even those not suitable for the growth of other plants. All it needs is plenty of water, sunlight and carbon dioxide. It should be noted that higher concentration of algae cells reduce the ability to absorb sunlight. Systems that may be used for cultivation include closed loop system, photobioreactors, and open ponds.
Once it is harvested, the wet algal biomass is converted to combustible fuel. This stage is challenging and occurs in a series of steps that differ depending on the strain. In most cases, manufacturers dehydrate the algae and use solvents to extract energy-rich compounds. Standard industrial procedures are then used to process the extracted compounds.
Some manufacturers use an approach that continually exposes wet algal biomass to high temperatures, approximately 6620 F, and pressures of 21,000 kPa. The resulting product is crude oil, which can be refined further to make gasoline, diesel or even aviation fuel. Up to 70% of algae’s carbon can be converted to fuel. Other products that arise from the production process include fuel gas, water, potassium, nitrogen and phosphorous.
It will be a while before algae fuel is commercially produced and that’s a future we look forward to. A joint effort between policymakers, public stakeholders, researchers and industries is crucial to ensure algal fuel becomes a reality. And whilst it’s not perfect, its advantages over fossil fuels and biofuels make it a great alternative.