Volkswagen is testing diesel fuel derived from algae in two of its turbodiesel models, a project that could push renewable fuels closer to the mainstream. Since July 2012, a VW Passat TDI and a Jetta TDI have covered about 20,000 miles running exclusively on fuel made by Silicon Valley startup Solazyme. The year-long test, a joint effort between the automaker and Solazyme, will produce results later this year.
VW engineers will pay close attention to the cars’ injectors, high-pressure pumps, sensors, and hoses. They want to ensure these parts are aging and wearing no differently than those in conventionally fueled TDI cars.
Solazyme’s process is conceptually simple.
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It uses industrial-scale fermentation to grow algae that turn carbohydrate feedstocks into oils. Those oils are made of custom carbon chains that vary with the end use. Dan Philips, the firm’s director of fuels, noted that the company’s Soladiesel fuel meets all ASTM standards for modern ultra-low-sulfur diesel fuel, specifically the D975 specification. That means it should run properly in any current diesel car, setting it apart from some other biodiesel fuels that rely on recycled cooking grease or after-market conversions.
The testing of the two VW TDIs is part of a broader effort to show automakers that renewable diesel fuel, meeting all relevant specifications, is safe for new vehicles. Soladiesel is already sold in about 1,200 locations around the globe.
A recent 30-day market test of a B20 blend — 20 percent algae-derived diesel fuel mixed with 80 percent conventional diesel fuel — at four Propel Clean Fuel Points stations in the San Francisco Bay Area showed strong consumer interest. Seventy percent of buyers said they would buy an algae-derived fuel more often, and four in 10 said they would pay a premium for it. Sales at those four stations were one-third higher than at non-participating stations during the trial period.
Independent testing of the B20 blend by the National Renewable Energy Laboratory showed reductions of 10 percent in total hydrocarbon emissions, 20 percent for carbon monoxide, and 30 percent fewer tailpipe particulates. Life Cycle Associates indicates that 100-percent Soladiesel reduces greenhouse gases by 85 to 93 percent compared to conventional petroleum diesel fuel.
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The B20 fuel can be used in most new diesel vehicles, including the 2014 Chevrolet Cruze Diesel arriving at dealers later this year. That kind of compatibility matters because, for a fuel to gain traction, it has to work with engines people already own, not just future prototypes. The company’s plant in Peoria, Illinois, is already running. Two more facilities, in Clinton, Iowa, and São Paulo, Brazil, are scheduled to come online early and late this year, respectively.
Beyond cars: shipping, military, and aviation tests
Soladiesel has also been tested by the Maersk shipping company and the U.S. Navy in ships. Its jet fuel, Solajet, has been tested by both the U.S. Air Force and United Airlines. Philips spoke Tuesday at “Silicon Valley Reinvents the Automobile,” a presentation by the Western Automotive Journalists association and SAE International.
The company defines its mission as transforming “a range of low-cost plant-based sugars into high-value oils,” using custom microorganisms that end their life with most of their body weight as oils. It focuses on three markets: fuels and chemicals, nutrition, and skin and personal care. Over the last several years, a huge amount of research and development money has gone into sustainable fuels derived from plants and other carbohydrates, including corn-based ethanol — which has become increasingly controversial. The firm’s approach, built on them rather than food crops, avoids some of those land-use and food-price arguments, though scaling it commercially remains the real challenge.
