10 Edible Biofuels

Drinking from a car's fuel tank is never advisable. The gasoline and petroleum-based diesel fuels that drive most vehicles today are far from being safe or nutritious for consumption.

However, this is evolving. For decades, a growing sector has been exploring alternatives to fossil fuels, with a significant focus on biofuels -- substitutes derived from natural plant oils [source: Demirbas]. In certain scenarios, unprocessed vegetable oil can even fuel standard diesel engines. After all, Rudolph Diesel initially designed his engine to allow farmers to power equipment using locally sourced fuel. Yet, pure vegetable oil, while a biofuel, has its drawbacks. The glycerin in natural oils raises their viscosity, causing them to solidify in cold conditions -- similar to bacon grease in a fridge. This poses challenges for fuel systems, filters, and injectors in colder climates like Alaska.

Chemists have developed two solutions to this issue. Certain plants, like corn, contain sugars that, when fermented similarly to beer or liquor, produce ethanol, an alcohol suitable for fuel. Ethanol is often used as a gasoline additive to reduce smog, as seen in E85 [source: Chu].

Plants like soybeans are more suitable for biodiesel production. This method involves mixing a catalyst into the oil to separate glycerin from the oil's fatty acid alkyl esters [source: Pimentel]. Once the glycerin is removed, biodiesel can efficiently power most diesel engines with fewer issues related to clogging or cold weather.

The infrastructure for biofuels is still evolving globally, and some biofuel production methods lack the efficiency needed for large-scale implementation [source: Pimentel]. However, the growing demand for eco-friendly alternatives to fossil fuels suggests that the fuel in your vehicle may soon resemble the food on your plate. To explore the potential of biofuels, continue reading to discover 10 edible biofuels that could fuel both you and your car.

10: Corn

In addition to being a dietary staple in the West, corn has gained significant traction as a biofuel. Its widespread availability and high sugar content, ideal for ethanol production, make it a common ingredient in E85 gasoline blends, familiar to many drivers.

Ethanol production involves converting corn from food to fuel by breaking it down into its core components: lignin, which strengthens plant cell walls, and cellulose, which holds the plant's sugars. The cellulose is then fermented to create ethanol, a potent form of alcohol derived from corn mash [source: Shakashiri]. This refined ethanol is often mixed with gasoline to reduce smog but can also be used as a standalone fuel.

In the U.S., corn-based ethanol serves as a homegrown alternative to imported fossil fuels. However, it has its downsides. Studies indicate that the energy required to produce corn ethanol—from farming equipment to fertilizers—consumes more fossil fuels than the ethanol itself replaces [source: Pimentel]. Additionally, growing corn in arid regions strains water resources, especially as farmers increasingly focus on ethanol production for income [source: McKenna].

Economic factors also play a role. Corn is already in high demand for food, animal feed, and industrial uses. Ethanol production further intensifies competition for corn supplies, driving up prices for the crop and its byproducts. Considering these challenges, while corn is a valuable biofuel, it is unlikely to single-handedly reduce the world's reliance on fossil fuels.

9: Soybeans

Soybeans might be the most adaptable biofuel on this list. Not only are they a dietary staple across continents, but they have also been transformed into diverse products, from ink and crayons to biofuels [source: Scharlemann]. While corn dominates ethanol production for blending with gasoline to reduce smog, soybeans are the primary source for the oil used in biodiesel production.

To create biodiesel from soy, producers first extract oil from the beans. With about 20 percent of the bean being usable oil, soybeans are exceptionally suited for this process. After extraction and filtration, the oil is combined with a catalyst to remove glycerin, resulting in a product that can be directly used in diesel engines.

Biodiesel offers several advantages over traditional petroleum diesel, aside from being renewable. It burns more cleanly, reducing the emission of particulate matter that contributes to smog and health issues.

8: Palm Oil

Palm trees offer more than just tropical beauty and coconuts. The high-carbon shells of their fruit can be transformed into water purification filters, while their leaves and wood have been used for building and shelter for thousands of years. Now, the oil from their seeds is being explored as a potential large-scale biofuel.

However, palm oil highlights a significant challenge in biofuel production. The land, energy, and financial resources required to produce it often outweigh the benefits of the final product.

Palm oil is a key crop in Southeast Asia. As demand grows for palm oil to produce biodiesel, plantations in countries like Malaysia and Indonesia are clearing large areas of rainforest to plant more oil palms. The transportation and production processes involved in exporting palm oil to fuel-hungry Western nations further increase fuel consumption and emissions. While palm oil isn't the only biofuel facing this issue, its affordability and popularity have brought this dilemma into sharper focus [source: Rosenthal].

7: Used Cooking Oil

If you've recently enjoyed French fries, onion rings, or fish and chips, you might have indirectly contributed to a popular edible biofuel: used cooking oil.

Even after frying food, cooking oil retains the fatty acid alkyl esters that make it suitable for use in certain diesel engines. By filtering out food particles and breading residue, innovative biofuel producers can create biodiesel or directly use the oil in diesel engines with "greasecar" technology.

Given the abundance of fast-food restaurants and the popularity of fried dishes worldwide, used frying oil appears to be one of the most accessible biofuels. However, it isn't without its challenges.

One major issue is the presence of food remnants in used frying oil. Removing these particles, especially when flour is involved, can be a laborious and time-consuming task. Filtering large quantities of oil is often impractical for mass production. Additionally, the oil's composition can vary widely, as it may come from peanuts, corn, or other plant sources, making it difficult to predict the fuel's consistency and potency.

Despite these challenges, many greasecar and biodiesel enthusiasts are willing to overlook them. Since fry oil doesn't require costly extraction equipment, it remains a favorite among DIY inventors, experimenters, and budget-conscious individuals looking to reduce their reliance on petroleum.

6: Peanut Oil

The versatile peanut, technically a legume rather than a nut, is one of the most beloved foods in Western cuisine. From mixed nuts and peanut-based candies to the classic peanut butter sandwich, this humble legume holds a special place in our diets.

Beyond its culinary uses, the peanut has numerous applications, many of which were pioneered by the famous African-American botanist Dr. George Washington Carver. His research documented over 300 uses for peanuts, including dyes, plastics, and even potential biofuel from its oil [source: Fishbein].

However, the peanut's popularity works against it in the biofuel industry. With peanut oil being highly sought after for food, medicine, and industrial purposes, it is too valuable to be economically viable as a biofuel. Market demand keeps its price too high for it to be a practical option for edible biofuels at this time.

5: Cottonseed Oil

Cotton isn't typically thought of as a food source, as its primary use globally is for textile production. However, cottonseed oil, derived from cotton seeds, is a light and mild-flavored vegetable oil that has been used in American cooking since the 1860s [source: NCPA]. While it has also served as animal feed, excessive use can cause nutritional issues in livestock [source: Osborne].

Using cottonseed oil as a biofuel is logical: some studies suggest it yields more oil per acre than corn or soy, two leading biofuel sources [source: Journey]. However, cottonseed oil faces a significant limitation, a common issue among many biofuels.

Cottonseed oil solidifies at low temperatures, making it impractical for vehicles in winter without a heating system to keep the oil above its gel point. While soy biodiesel also faces this issue, it gels at -16 degrees Celsius, whereas cottonseed oil solidifies at just -1 degree Celsius. Since many regions experience colder temperatures regularly, pure cottonseed oil is not ideal for widespread biofuel use.

4: Safflower

Safflower has a rich history, with its yellow flowers and oil-rich seeds once used to dye cloth for ancient mummification processes. Today, it is widely used in natural medicine across both Eastern and Western cultures. Additionally, safflower seed oil serves as a healthier alternative to other cooking oils.

With its low gel point, safflower oil is a promising candidate for biodiesel production. However, its limited agricultural popularity poses a challenge. In 2004, global safflower production was only 604,000 metric tons, a sharp decline from the 800,000 to 900,000 tons produced annually in the mid-90s. To meet biofuel demands, safflower production would need to increase significantly, reversing this downward trend [source: Jimmerson].

3: Linseed Oil

Linseed, or flaxseed, oil exemplifies the adaptability of many vegetable oils with biofuel potential. Woodworkers often blend it with a thinner, like turpentine, to treat indoor furniture, fixtures, and hardwood floors. The oil seeps into the wood, preventing dryness, cracking, or scuffing. Outdoors, a similar application protects wood from excessive moisture, which can accelerate weathering and decay [source: DIY].

In its pure form, linseed oil has proven beneficial for human health. Similar to other vegetable oils, it has been shown to reduce cholesterol levels and support heart health [source: Ridges].

Flax fibers are used to produce linen, making this biofuel crop doubly valuable. Both the oil from its seeds and the fiber from its stalks can be utilized, giving linseed oil an edge over other biofuel crops that lack such versatile applications [source: Shirke].

2: Sorghum

Sorghum ranks among the world's most vital cereal crops and is a key agricultural export for the United States [source: Council]. It is used in a wide range of foods, from beverages to baked goods like cakes and cookies. Certain gluten-free, antioxidant-rich varieties are particularly valued by health-conscious consumers.

Sorghum also stands out as a potential biofuel powerhouse. Its adaptability to various climates and compatibility with corn-based ethanol production processes make it a strong candidate. Researchers are actively developing hybrid sorghum strains tailored for biofuel, suggesting that the E85 fuel in your car might soon share a connection with the molasses cookies on store shelves [source: Lau].

1: Water

While water isn't technically classified as a biofuel, it is an essential natural resource crucial for life. However, with the help of a surprisingly straightforward technology, water could eventually become a viable fuel source.

Through the process of electrolysis, where an electric current passes through water, the liquid is split into its basic components: hydrogen and oxygen [source: Nave]. Hydrogen is a highly efficient fuel, offering three times the energy per pound compared to gasoline and burning without the harmful emissions of traditional petroleum fuels [source: Stanford].

However, producing and storing hydrogen presents challenges. Transporting large quantities of this lightweight, highly flammable gas globally raises significant safety concerns. Additionally, storing enough hydrogen for long-distance travel would require impractically heavy and secure fuel tanks [source: Planet].

Despite these challenges, hydrogen remains a promising option. Innovations like the Garrett Water Carburetor, which uses a hydrogen-producing cell powered by the vehicle's generator, have gained attention. Modern adaptations of this concept involve injecting hydrogen into gasoline engines to reduce emissions and improve fuel efficiency. While cost, reliability, and development hurdles remain, it's possible that water from your tap could play a role in powering your car in the near future [source: Brooks].