A number of studies show biodiesel's emissions improvements. There are variables: emissions depend on feedstock and application; light-duty vehicles will differ from heavy-duty vehicles; and all duty/drive cycles will have different results within their size/weight classes. Lots of work is being done currently, and new data should be available soon.
All that said, let's use the numbers from
National Biodiesel Board (by all accounts very conservative). Compared to petroleum diesel, using B100 (pure biodiesel) reduces unburned hydrocarbons (greenhouse gases) by 67 percent, carbon monoxide by 48 percent, and particulate matter by 47 percent. Biodiesel essentially has a closed carbon cycle if you include the feedstock plant growth.
And here's news: Nitrogen oxide (NOx) emissions have been a concern about biodiesel. NOx is a low-level smog agent, and increased NOx emissions have been a major barrier to biodiesel adoption in states like California. It turns out biodiesel may not increase NOx emissions after all. In a comprehensive new study to be released later this fall, the Department of Energy has found B20 in transit buses to have equal or less NOx emissions than petroleum diesel. The National Renewable Energy Laboratory's fuels-performance manager, Wendy Clark, said that after exhaustive testing of biodiesel emissions on two 40-foot urban transit buses, NOx emissions were comparable to the buses' diesel-fuel emissions. In other words, they found no increase in NOx emissions from biodiesel.
Many of the processes involved in creating biofuels use oil -- pesticides on the crops, transportation to the processing station, powering the station, transportation to the fuel station for consumers. Is it true that by using biofuels, you are still consuming around the same amount of oil? -- William Ivanoff, Eugene, Ore.
No, it is not true. Biodiesel has an energy balance of 3.2 to 1, meaning it returns 3.2 units of energy for every 1 unit of input. Is the biodiesel lifecycle petroleum-free? No. Petroleum use is ingrained into every aspect of our society. We're making progress. One of our distribution partners is using B99 blend in his fuel-delivery trucks. Read more about biodiesel's energy balance in
this report [PDF] from the National Renewable Energy Laboratory.
Is biodiesel an early step toward reducing greenhouse gases from the transportation sector, but not a sufficient step? -- Ann Burruss, Greenacres, Fla.
Biodiesel is one step. At this point, the dream of emissions-free transportation is just that -- a dream. Biodiesel is available now, and that really means something. The time has come to take these technologies out of the lab and begin applying them. Biodiesel use significantly reduces harmful emissions. It's made in the U.S., and the feedstocks are grown by farmers, keeping more of our dollars in local economies. Given our current situation, any well-thought step forward is a sufficient step.
What's the best way for individual diesel-car owners to get their local service station to offer biodiesel? I live in a small town, but there are a substantial number of biodiesel enthusiasts here who are turning to veggie-oil conversions in the absence of a reliable biodiesel supply. -- Sonia Marcus, Athens, Ohio
Retail station owners need to believe they can sell biodiesel before they'll offer it. If your local retailer feels enough interest from customers, they may begin to consider selling it. You'll need a high-quality, stable source of biodiesel to sell commercially -- the best place to start is to find a large, local fuel distributor who's working with biodiesel. You could have the station owner contact
Propel Fuels, since setting up retail stations is what we do.
In short, keep asking. Have all your local biodiesel supporters focus on one station owner with questions and letters promising to buy it. Eventually one of the stations will come around. Good luck!
What are your thoughts on home-brewing biodiesel? -- David Kirshbaum, Stinesville, Ind.
I don't have an opinion on home-brewing biodiesel. It's legal (as long as you pay your road taxes). Brewing your own takes a commitment in time and energy. If you feel safe and secure home-brewing, I say go for it. There's a ton of information available on the web to get you started. You'll get all the glory and all the blame -- if bad biodiesel damages your engine, it's all your fault!
How does one overcome the cold-weather gelling issue with biodiesel? -- David Kirshbaum, Stinesville, Ind.
Typically, by blending biodiesel with petroleum diesel or kerosene. A 50/50 blend will be fine to 20 degrees Fahrenheit. There's a ton of new research into winterized fuel additives, some more bio-friendly than others. My hope is a simple additive solution by this winter. Petroleum diesel has some gelling issues as well, so those in very cold climates tend to be somewhat familiar with winter fuel strategies.
Why are there no hybrid-diesel engines on the U.S. market? Do such vehicles exist elsewhere in the world? -- Rob Hardison, Seattle, Wash.
There are hybrid diesels in production. In fact, you may have seen the new King County Metro hybrid-diesel buses in Seattle. The problem with diesel-vehicle availability in the U.S. is our diesel fuel. Clean up the fuel, and we'll have more vehicle options. Every other country that's serious about increased efficiencies in personal vehicles is using diesel as a pillar technology. New diesel-fuel requirements are being phased in; beginning in 2007, we should see many more vehicles available for consumers.
I asked VW about the use of biodiesel in my car and the reply was that if I used more than 5 percent biodiesel, it would void my engine warranty. Any thoughts on that? -- Henry Bosch, Catonsville, Md.
I can't speak for VW. The position of the National Biodiesel Board is that vehicle manufacturers don't warranty any fuel, including biodiesel. You'll be looking at this "voided warranty" issue if you fill with bad dino-diesel as well. If VW finds you are running B7, will they refuse to cover the broken trunk latch? I doubt it. VW is fine with B100 use in the TDI engine in Europe. Many folks run B100 in new VWs.
Why are legislators so eager to push ethanol and not biodiesel? -- S. Bean Nymphem, Mount Kisco, N.Y.
Ethanol is a much larger and more mature industry than biodiesel. Ethanol and biodiesel are often lumped together in legislation. I'd like to see more separation of the two fuels, as biodiesel has different benefits and applications.
