15 Advantages and Disadvantages of Using Algae as a Biofuel

There are several valid reasons to be looking at biofuels today as an alternative to the products that we currently use. Oil prices can fluctuate rapidly, sometimes creating a price for fuel that negatively impacts households around the world. Some countries may want to look for ways to lessen their dependence on foreign products. We can even look at restoring cash crops to food resources (such as corn) to avoid the ethical question of using croplands for fuel instead of hunger.

These are all positive elements to consider when looking at algae biofuel resources. This natural product uses photosynthesis to create oils that consume carbon dioxide. It grows in both closed-tank bioreactors and open-pond systems. Some strains are so productive that the oil they produce could be harvested each day.

There are economic and environmental advantages to consider with this developing industry, while there are disadvantages that we must avoid as well. That is why it is essential to review these algae biofuel pros and cons.

List of the Pros of Algae Biofuel

1. Bio-based fuel offers carbon-neutral combustion.
The structure of algae biofuel is beneficial because it absorbs as much carbon as it releases because that is what it uses for food. If we used algae biofuel, we would end up with a result where our net consumption would be the same as if we had never grown the algae in the first place. That means we have access to a fuel source that is inherently renewable without creating a negative impact on our environment. Even if we consume high levels of it, the neutrality of its existence means we would cut emissions compared to the levels they are at today.

2. It would work with our current system of fuels.
Another advantage of using algae biofuel is that it would become a direct and immediate replacement of the fuels that we already use in various industries. The product can be refined in a similar way to petroleum products, which means it becomes useful within our current infrastructure. Qantas and United Airlines have both tried using blends of algae biofuel with up to 40% mixtures and have completed successful trials of the product.

3. It is abundantly available even without commercial processing.
Algae has the capability of doubling in size over a 24-hour period. It can grow in numerous locations as well, including in the water supplies that are around power plants and paper factories. We could potentially have access to more energy resources with this biofuel than we would if we continued to concentrate on petroleum products. Since the reserves of crude oil, coal, and natural gas are expected to be gone in 60-80 years, this product could be a realistic alternative.

4. It can produce numerous byproducts, just like petroleum hydrocarbons.
We can use hydrocarbons made from plant-based materials in the same way that we use hydrocarbon made from petroleum-based items. That includes being able to make fertilizers, industrial cleaners, soap products, and feed stocks. Algae grows with enough abundance that the refinery processes could be immediately profitable if commercial growing methods became available. This flexibility means that algae biofuel is even an alternative to diesel fuel.

5. It is a renewable resource.
Unlike other fuels that we use today that are based on fossil fuels, algae is renewable. When we want to have more of it, then all we need to do is grow some more. A study published by Water Resources in 2011 found that the most viable strains of algae could create enough biomass through commercial cultivation to replace roughly 48% of the petroleum products that the U.S. imports each year.

6. It is extremely productive from an overall supply chain standpoint.
We already create several biofuels from other natural products, such as sugarcane, corn, and switchgrass. Algae offers roughly 80 times more oil per acre than sugarcane, corn or switchgrass. It is closer to being carbon neutral than these other options, and has the advantage of not being part of the regular human food chain.

7. It is a crop that we can grow with high levels of efficiency.
Algae can grow in almost any climate. As long as there is enough sunlight available, then it will have the capability to grow. We don’t need to worry about clearing forest space or converting croplands to create this fuel resource. It can even grow in spaces that would be inefficient for other forms of agriculture.

List of the Cons of Algae Biofuel

1. It requires large amounts of water to be productive.
Whether algae grows in an open pond or a closed bioreactor, it must have a significant water source available for it to maximize growth. When you maintain temperatures at the appropriate levels to encourage this outcome, then the liquid begins to evaporate. That is why this biofuel uses much more water than other resources using current technologies. Although recycled wastewater and natural farming methods could reduce this disadvantage somewhat, there is still the threat of water diversion occurring if this opportunity is pursued.

2. It requires significant fertilizer use.
We can grow algae in massive quantities only when there is sufficient fertilizer available to the producers. It would require up to 15 million metric tons of nitrogen to create enough algae to create 39 billion liters of biodiesel through this effort, along with 2 million metric tons of phosphorus, which represents roughly half of what is already in use on American croplands today. Some of these nutrients come from petroleum-based products, which are not carbon neutral. There is also the threat of run-off that could impact local waterways.

Anderson Lake State Park in Washington encounters issues with run-off frequently during the summer months, even though the land around the water is no longer used for cattle grazing. Algae growth around a similar resource would be a significantly greater issue to manage.

3. It has high production costs using current technologies.
Solix was able to create biodiesel from algae as early as 2009 using current technologies, but it came at a high price. You would need to pay about $33 per gallon because of the energy levels required to circulate gasses and materials inside bioreactors to encourage growth. Estimates back then suggested that the price of this resource could eventually come down to $5.50 per gallon. If the byproducts of this commercial product could also be sold, then pricing might decrease to $3.50 to $4 per gallon. That is still the equivalent of crude oil being at $150 per barrel.

The current goal for this industry, according to the Office of Energy Efficiency and Renewable Energy, is to reach this pricing goal by the year 2030.

4. It takes time to allow algae to create biofuels we can use.
Although you can harvest some algae strains on a daily basis, that doesn’t mean you’ll receive a biofuel product that you can use immediately. There are several steps that must be followed before this natural product can become a usable fuel source. The oil press is one of the fastest and easiest methods, extracting up to 75% of the oil from the algae. Hexane solvents can extract up to 95% of the oil, while supercritical fluids can extract 100%.

Then you must refine the oil using fatty acid chains through a process called transesterification. This transformation uses a catalyst to create a fuel and glycerol mixture that can then be refined to remove the glycerol. We can still produce petroleum fuels faster.

5. It has regional suitability issues.
The varying climates that are found throughout the geographic regions of our world dictate the types of crops we can cultivate. Biofuel plants will grow better in specific regions than others if you are using outdoor cultivation methods. Although algae does have some benefits with weather tolerance, it does not have the flexibility to grow in places where there is extreme cold. You could grow lemons in Alaska, but it would need to happen inside. That means it would cost more in the long run.

6. It is not always an energy-efficient product.
When you produce biofuels like biodiesel from algae, then it takes the energy equivalent of several gallons’ worth of a petroleum-based fuel to produce a single gallon of the eco-friendly variety. Using current farming techniques, it can take roughly 120% more energy to produce a gallon of algae biofuel when compared to the energy it contains. This ratio is one of the reasons why early adopters of this resource are trying to lower the per-gallon cost as quickly as possible.

7. It may create variations in the quality of the biofuels reaching the market.
The oil in the algae is pressed out, filtered, refined, and then converted into fuel. Although different crops use the same techniques, the ability of this resource to generate power can vary widely. On one end of the spectrum, the average acre of corn produces 18 gallons of ethanol. If you turned oil palm into a fuel, then you would receive 635 gallons per acre. Algae offers the potential to generate 10,000 gallons of biodiesel per acre, but only if specific species are used to create it.

8. It would have the same issues we see in monoculture.
When farmers grow one crop in a concentrated manner, then it increases the risk of pests and water pollution impacting the quality of the eventual fuel that reaches the market. Monoculture issues would impact algae production as well. Growers would eventually settle on the strains which produce the most oil, thus limiting the diversity that would be available. The outcome could result in problems with pest control, water pollution, or a total loss. If a disease strikes the algae and there is no other species, then the advantages of this product would disappear immediately.

The pros and cons of algae biodiesel are encouraging because it gives us an opportunity to for another proven fuel alternative. Although the price of this fuel is still quite expensive, there are several research projects working right now to lower those costs. In the next ten years, we may find that biodiesel products made from algae are dominating at the pump, helping us to create a cleaner world with every mile we drive.