It may be a little corny, but learning about the future of biofuels is a-maze-ing! In this episode of Tomorrow’s World Today, Darieth visited the company POET located in South Dakota. There, she learned about their process of turning corn stover into biofuel, a renewable energy source. Luckily, corn isn’t the only crop out there that researchers have been able to convert into biofuel. Here are some of the top energy crops and why each of them may be the future of fuel.
Similar to corn, the cellulose in switchgrass can be used to make ethanol. But one of the many benefits of utilizing switchgrass is that less fossil fuel energy is needed to create ethanol using switchgrass than corn. The problem is that switchgrass isn’t as abundant as corn; there are no farms or plantations growing it in large quantities. However, because of its possible energy benefits, scientists are beginning to change that. For example, at Auburn University in Alabama, test plots of switchgrass were grown which produced 15 tons of biomass per acre. Scientists have also said that every acre of switchgrass would be able to produce 1,150 gallons of ethanol per year.
Another benefit to switchgrass is that it takes less fertilizer, pesticides, and water to grow than typical plants. In fact, it is able to grow on marginal land not typically used for farming. So farmers could grow switchgrass without taking up space that would typically go to other crops. Switchgrass is also perennial, which means it will only need to be planted once. Because of all of these factors, scientists have concluded that switchgrass produces five times the amount of energy it takes to grow. This is an important statistic for harvesters of energy crops to keep in mind.
These organisms can be grown in saltwater, municipal lake lagoons, or shallow manmade basins… oh, and did we mention they produce 200 times more oil per acre than soy? For this reason, the United States Department of Energy and many large oil companies are putting millions into scaling up the production of algae. Certain quirks of the plant have made mass-production difficult, but companies like Exxon Mobil have been working to help make algae production more cost-effective.
Carrizo cane, or giant reed, is an exotic plant that grows along wetlands and river banks. It grows roughly twenty to thirty feet tall in a year’s time and is able to be used to produce ethanol, similarly to corn and switchgrass. Scientists have found, however, that carrizo cane is able to produce more biomass per acre than any other plant on earth. The problem, however, is that the plant has invasive tendencies, even choking out other native plants in the areas it currently grows. It, therefore, would be difficult to implement in terms of farming practices.
The plant is currently being harvested on a mass scale in Europe where it is a native species. Efforts are being made in the United States to harvest the carrizo cane that already exists, which is growing in southern regions of the country from Florida to California. Harvesting the plant will not only allow one to extract energy but also allow other plant species to thrive more fully.
Another oil-based plant, hemp seeds have a surprisingly high content of oil. Hemp can grow on marginal land and is very low maintenance, but it is able to produce roughly 4 times as much oil per acre as soybeans. The only obstacle when it comes to production is that it is still illegal to grow hemp in most states, though a few states have changed their laws on this in 2018. Outside of the United States, however, countries like France and Canada have begun to grow hemp for fuel on a small scale.
Although this plant is poisonous to both humans and livestock, the seeds it contains are 40 percent oil. Seeing the plant’s potential in terms of energy crops, tens of thousands of acres of jatropha were planted in the mid-2000s in India and Africa. Although the plant is able to thrive on marginal land, planting it in high-quality soil with irrigation is the only way to yield the best results when it comes to oil production. African countries have continued to invest in the plant while researchers work on breeding new and improved varieties.