Biodiesel Blends
While I do believe that the use of pure biodiesel (B100) can be practical in certain applications; commercial trucking isn't one of them. Note, please, that I said PURE biodiesel isn't suitable for use in the trucking industry. BLENDED biodiesel, however, is not only suitable for use in trucks; it's my personal opinion that it's superior to standard petrodiesel products.
When used in a 20% biodiesel and 80% petrodiesel blend, known as B20, nearly all the disadvantages of B100 are either mitigated or disappear completely. In their place appear several distinct direct and indirect advantages. For example:
- Reduced CO2 Emissions: Using pure biodiesel (B100) results far lower carbon dioxide and carbon monoxide emissions than petrodiesel while a blend like B20, although not nearly as great, still results in significantly lower CO2 and CO emissions of about 12%.
- Reduced Hydrocarbon Emissions: The total unburned hydrocarbon emissions of B20 are approximately 20% lower than those of #2 diesel fuel.
- Nitrogen Oxide Neutral: This is especially important since the 2010 EPA standards require a 90% reduction in NOx over the 2004 standards.
- Increased Lubricity: Injection systems have always relied on diesel fuel as a lubricant but ULSD falls far short of the lubricity levels required to maintain proper injection system lubrication; at least without additional additives. The use of biodiesel blended with petrodiesel, however, not only provides the necessary lubrication, it actually provides higher lubricity levels than standard North American #2 diesel fuel ever did.
On September 1, 2006 the state of California became the first state in the nation to start pumping ultra-low sulfur diesel (ULSD). At 15 parts per million, down from the 150ppm allowed in California and the 500ppm for the rest of the nation, ULSD is virtually free from sulfur. Vince McBride of the Michigan-based Diesel Technology Forum has stated that the change to ULSD is "a huge environmental achievement...comparable to when lead was removed from gasoline." The rest of the nation began selling ULSD in mid-October of 2006.
- Increased BTU Input/Output Ratios: A study released in July 2005 by the Center for Transportation Research, Argonne National Laboratory, compares the net energy balance of corn ethanol to petroleum. The report states that ethanol requires 0.74 Btu of input compared to 1.23 Btu of input for petroleum to produce the same output of energy. It's assumed that similar input/output ratios hold for biodiesel.
- Increased Farm Revenues: Higher demand for crops that can be refined into biodiesel will result in higher farm revenues.
- Reduced Farm Subsidies: High domestic demand for crops suitable for fuel production should negate the need to spend taxpayer's money for fallow farmland.
- Increased Domestic Energy Jobs: Although the estimated numbers vary greatly it stands to reason that jobs of all kinds will increase along with increased demand for biodiesel. Refineries need to be built and staffed so engineering, construction, maintenance, and production jobs will need to be filled.
- Reduced Foreign Oil Imports: If we're reducing the need for petrodiesel by 20% it naturally follows that a corresponding reduction in foreign oil imports will result. Actual estimates on the overall reduction in dependency vary but most studies put the number between 19% and 30%.
- Competitive Pricing: Biodiesel, considering current petrodiesel pricing, is on an even footing. With more demand fueling an increase in biodiesel refining capability its likely that the wholesale cost will remain competitive for the foreseeable future. Reducing the demand for petrodiesel by 20% will likely lead, if not to a reduction in price, to price stabilization.
And there's more. The most important factor in deciding to choose a biodiesel blend instead of North American #2 diesel, at least for most of us, rests in overall cost and efficiency. In general, no matter whose numbers you're using, the energy (BTUs) contained in B20 is between 1.5% and 2% lower than that of #2 diesel fuel.
You would think that this would translate into a corresponding reduction in fuel mileage but, instead, it seems that the slightly higher Cetane rating of B20 over #2 results in slightly higher fuel mileage. Unfortunately no recent B20 fuel mileage studies have been done using over-the-road trucks so these numbers are difficult to confirm conclusively.
Another major concern that makes the use of B100 unworkable in over-the-road trucking is related to the higher gel temperatures. While the gel temperature of B20 is significantly lower than that of B100; its still about 5-10 degrees higher than that of #2 diesel. This difference, though, is completely erased if the petrodiesel used in the B20 blend is winterized.
Finally, the one debilitating trait that blending biodiesel and petrodiesel doesn't diminish is the solvent characteristics inherent in biodiesel. Most hoses installed in newer trucks should be synthetic and, therefore, impervious to biodiesel deterioration but any build-up of dirt and grime will still be washed into the filters; requiring them to be changed within 1000 miles of first using B20. That's an irritation but it seems to me that a clean fuel system is a happy fuel system.
Conclusions
Do I think that biodiesel is the answer to all our problems? Hardly; but I do think it's a step in the right direction. I like the idea of using a renewable fuel that reduces our dependency on foreign oil imports. I like the idea of energizing our economy by improving farm revenues, reducing farm subsidies, and creating good jobs. And I like the idea of using a biodegradable fuel that's eco-friendly. Just because I'm not a dyed in the wool environmentalist doesn't mean I can't support a good idea when I spot one.
By no stretch of the imagination have I come close to touching on all the relevant points regarding biodiesel; and I'd be more than happy to engage in an ongoing conversation. What do you think? Do you agree with me? Do you have any questions you think I can answer? Do you think I'm an idiot? Leave send me an email and let me know. I'll be happy to engage you in conversation, answer any question I can, and defend myself against charges of idiocy.
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|Biodiesel: Diesel Fuel From Farmers | Part 2: Basics & Drawbacks | Part 3: Blends & Conclusions |
