6 JULY 2017 • FOGHORN FOGHORNFOCUS: ENVIRONMENTAL ISSUES Improvements in Biodiesel Quality Helps Green WATERS Biodiesel quality has significantly improved over the last decade—and marine operators are increasingly using this alternative fuel in fleet op- erations to achieve emission reduction goals. The biofuel on the market today is a very different product than its engine-stalling, filter-clogging pre- decessor. The King County Marine Division in Seattle, Washington—a PVA Green WATERS member since 2015—operates three high-speed pas- senger-only catamaran ferries that transport commuters and tourists across Puget Sound. In January of this year, Director Paul Brodeur made the decision to increase the Water Taxi’s used cooking oil biodiesel blend from 10 percent to 20 percent. “Biodiesel may never be the ‘silver bullet’ alternative fuel to completely replace petroleum,” he said, “but for us and for marine operators elsewhere, biodiesel rep- resents a reliable, affordable, drop-in option to reduce carbon emissions. In our Cummins QSK-50 engines, we’ve experienced only positive results.” Brodeur’s experience is not unique. Since the mid-2000s, new regulations, advances in the refinement process, and increased demand for product consistency from vehicle and vessel operators has led to improvements to fuel reaching the market. For those who swore in 2007 to never use biodiesel again, it’s time to take a second look. What is Biodiesel? Biodiesel is a non-toxic, petroleum diesel alternative refined from vegetable oils (canola, soy, corn, palm and others), animal fats (lard and tallow), and used cooking oils (yellow grease) through a simple chemical process called transesterification, in which feedstock oils are reacted with alcohol to create biodiesel and glycerin. In most cases, 100 percent biodiesel, or B100 (the common nomenclature is “B” plus the percent biodiesel), is blended with petroleum diesel into 5-20 percent blends. Biodiesel has similar combus- tion properties to diesel fuel, but a few key differences have caused trouble in the past. First, biodiesel has solvent- like qualities. When introduced to an older engine, biodiesel will begin to remove sooty residues from inside the engine and fuel tanks. These residues will become trapped in fuel filters. It is recommended to initially change fuel filters on a more frequent basis after switching to biodiesel. Second, biodiesel has a higher cloud point than conventional diesel and in very cold weather, wax crystals may form in the fuel—another cause of restricted fuel filters. Lastly, long-term storage of biodiesel requires special consider- ations to prevent accumulation of water and algae growth. All these issues are now well understood by fuel refiners and vendors and proven solutions exist to plan for, avoid, or prevent all the issues that once plagued biodiesel users. What Changed? New industry standards and regu- lation led to significant improvement in biodiesel quality. Biodiesel standards are set by the American Society for Testing and Materials (ASTM) and regulated by the Environmental Protection Agency (EPA), both of whom are feedstock agnostic. The first major improvement came when ASTM developed a standard for biodiesel in 2001. Under this regulatory framework, all certified fuel was required to meet stringent requirements for cetane, flash point, cloud point, lubricity, sulfur content and other characteris- tics. Pure biodiesel is certified as ASTM D6751 and required in all subsequent Take Another Look at Biodiesel Fuel for Your Vessel By Alexander Adams, King County Water Taxi Figure 1: (Left) Lifecycle emissions of biodiesel at various blends compared to diesel fuel.Source: U.S.Department of EnergyAlternative Fuels Data Center,2017. Figure 2: (Below) Carbon IntensityValues for all Pathways.Carbon intensities of fuels varies by feedstocks and other lifecycle factors like transportation,land use and the refining process. Source:Anil Prabhu,CaliforniaAir Resource Board, 2017.