Scripps Research Vessel, ‘Sproul,’ Realizes Biofuel Milestone
by Judith Garfield (San Diego Community Newspaper Group) … In my first article “Scripps research on biofuels hits close to home Part 1,”readers traveled with me on Scripps Institution of Oceanography’s R/V Sproul as I helped carry out research on biofuel emissions with chief scientist Lynn Russell, Ph.D., and her research group. As we motored around California’s Channel Islands, the ship’s engine burned a new source of renewable biofuel. Biofuels are derived from living sources, such as vegetable oils and animal waste fats discarded by restaurants, while commercial diesel is a fossil fuel derived from petroleum.
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Pollutants were measured at four different engine speeds (700, 1,000, 1,300, 1,600 rpm) and included greenhouse gases (CO2, carbon monoxide, and nitrogen oxides) and black carbon aerosols (small particles like smoke and larger particles like soot). Ultimately, the Sproul traversed more than 14,000 miles and burned through 52,000 gallons of biofuel. That’s a lot of data to make sense of.
The Sproul study was unique in using a hydrogenated biofuel, a new process that is supposed to increase shelf life and allow the engine to run cooler than that of other tested biofuels processed differently. This study was also the first to measure emissions collected across an extended number of miles because when our day cruise was over, the equipment stayed aboard to independently collect data over a year of the Sproul’s travels.
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At lower speeds, the biofuel burned significantly cleaner in terms of greenhouse gas pollution (particularly CO2) but produced about the same amount of smoke and more soot than diesel. At higher speeds, the biofuel and diesel were comparable for greenhouse gas emissions, but the biofuel burned more smoke and soot overall than diesel. Both the biofuel and diesel affected lung tissue lining similarly, but these results were inconclusive because of the limited number of samples and the variability of atmospheric conditions. Finally, as advertised, the Sproul’s engine ran cooler and more efficiently with hydrogenated biofuel. What do we make of all this?
Before crowning the environmental winner, it is essential to consider not just emissions but the energy required to source and process each fuel type. Biofuel comes from living matter (easily grown and located above the ground), while diesel comes from petroleum, which must be extracted from deep in the earth via complicated, invasive practices (drilling, fracking). Because biofuels are easier and cheaper to access, process, and refine, they are more energy efficient from the get-go. And while not fully carbon neutral, the Sproul’s biofuel was 50 percent renewable, whereas diesel is considered zero percent renewable ….
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Ship owners will be more agreeable to cleaner, renewable fuels if we support the science that innovates ways to make biofuels more cost-effective, particularly as fossil fuels get more expensive. READ MORE
