Cellulosic Fuels
What is it?
Agricultural waste and other non-edible plant products such as stalks, husks, woodchips and grasses are cellulosic fodder for advanced ethanol production. The structural components of plants, or cellulose, can be processed by enzymes or acetogens, broken down into sugars and fermented to produce alcohol-based fuels like ethanol. Since cellulose is not used for food, is often an industry byproduct, and can be sourced from a variety of fast-growing plants, cellulosic-based ethanol is even more sustainable and energy-efficient than traditional ethanol.
Who’s doing it?
Fuel producer POET is dedicated to making cellulosic ethanol a mainstay in American fuel tanks. POET processes corncobs, leaves, husk, and stalk with specifically developed enzymes to generate cleaner burning, renewable ethanol. The company’s goal is to have 3.5 billion gallons of annual capacity by 2022, making great strides to meet the Renewable Fuels Standard.
Another producer, ZeaChem, uses a hybrid biochemical fermentation and thermochemical process to create their cellulosic fuels. As part of this process, ZeaChem employs naturally occurring acetogens – which produce acetic acids from sugars and produce no CO2 during fermentation – to create cellulosic fuels from biomass such as short-rotation hybrid poplar trees.
Algae-based Fuels
What is it?
The prolific nature of algae and its ability to thrive in marginal environments makes it an ideal candidate for renewable fuel feedstock. Microalgae plants use sunlight and consume CO2 for energy and can grow 20 to 30 times faster than traditional food crops. It is estimated that algae has the potential to produce 5,000 to 20,000 gallons per acre per year.
Who’s doing it?
Renewable oil producer Solazyme leads the industry with their proprietary microalgae, formulated to thrive in dark fermenters, consuming a variety of sugars and producing natural oils. Solazyme utilizes standard fermentation equipment, creating an efficient and scalable production process to bring oil-producing microalgae to commercial levels.
Waste-Based Fuels
What is it?
Waste feedstocks are often the most sustainable and environmentally friendly sources for biofuel production, and producers across the country are making this advanced fuel today. Some are creating high-quality fuel for use in diesel engines, and a variety of ingenious companies are pursuing technologies to process waste into clean burning ethanol. Waste sources can take many forms, from watermelon rinds to sewage, cardboard to landfills. And while no single waste source can entirely replace fossil fuels, the increasing variety of offerings can together help reduce dependence on petroleum.
Who’s doing it?
New Leaf Biofuel, a San Diego-based biodiesel production company, creates renewable biodiesel from waste products or recycled sources. New Leaf sources waste grease from local restaurants and processes and refines the waste oil into high-quality biodiesel. Since Propel strives to source the most local and sustainable fuels available, we’re proud to partner with New Leaf to offer high-quality, waste-based biodiesel at select Southern California Propel locations.
Renewable Diesel
What is it?
Also know as Green Diesel, like biodiesel, renewable diesel is sourced from sustainable oil feedstocks, used to produce a synthetic diesel product suitable for all diesel motors. Renewable diesel is manufactured to have the same chemical properties as petroleum diesel and can therefore be stored, sold and consumed using existing petroleum diesel technology. A wide-range of raw materials may be used to produce renewable diesel from plant oils to tallow or waste fats from rendering facilities.
Who’s doing it?
Dynamic Fuels of Louisiana, a joint venture of Tyson Foods, Inc., and Syntroleum Corporation, produces next-generation renewable diesel from animal fats, greases, and vegetable oils while significantly reducing lifecycle greenhouse gas emissions. Dynamic’s renewable diesel had lower sulfur levels than crude oil while offering high-cetane combustion and performance.
