Comments biofuels has made

Biodiesel and Emissions

Although Biodiesel does increase (although only slightly) NOx emmissions, it reduces several other key emissions.

The US EPA has done several key studies on Biodiesel emmissions.

This from the EPA Study:
http://www.utahbiodiesel.org/biodiesel_basics.html#EMISSIONS

"The overall ozone (smog) forming potential of biodiesel is less than diesel fuel. The ozone forming potential of the speciated hydrocarbon emissions was nearly 50 percent less than that measured for diesel fuel.

Sulphur emissions are essentially eliminated with pure biodiesel. The exhaust emissions of sulphur oxides and sulfates (major components of acid rain) from biodiesel were essentially eliminated compared to sulphur oxides and sulphates from diesel.

Criteria pollutants are reduced with biodiesel use. The use of biodiesel in an unmodified Cummins N14 diesel engine resulted in substantial reductions of unburned hydrocarbons, carbon monoxide, and particulate matter. Emissions of nitrogen oxides were slightly increased.

Carbon Monoxide
-- The exhaust emissions of carbon monoxide (a poisonous gas) from biodiesel were 50 percent lower than carbon monoxide emissions from diesel.

Particulate Matter
-- Breathing particulate has been shown to be a human health hazard. The exhaust emissions of particulate matter from biodiesel were 30 percent lower than overall particulate matter emissions from diesel.

Hydrocarbons
-- The exhaust emissions of total hydrocarbons (a contributing factor in the localized formation of smog and ozone) were 93 percent lower for biodiesel than diesel fuel.

Nitrogen Oxides
-- NOx emissions from biodiesel increase or decrease depending on the engine family and testing procedures. NOx emissions (a contributing factor in the localized formation of smog and ozone) from pure (100%) biodiesel increased in this test by 13 percent. However, biodiesel's lack of sulphur allows the use of NOx control technologies that cannot be used with conventional diesel. So, biodiesel NOx emissions can be effectively managed and efficiently eliminated as a concern of the fuel's use.

Biodiesel reduces the health risks associated with petroleum diesel. Biodiesel emissions showed decreased levels of PAH and nitrited PAH compounds which have been identified as potential cancer causing compounds. In the recent testing, PAH compounds were reduced by 75 to 85 percent, with the exception of benzo(a)anthracene, which was reduced by roughly 50 percent. Targeted nPAH compounds were also reduced dramatically with biodiesel fuel, with 2-nitrofluorene and 1-nitropyrene reduced by 90 percent, and the rest of the nPAH compounds reduced to only trace levels."

Here's some links to some pertinent information:
EPA Emissions Study
http://www.utahbiodiesel.org/biodiesel_basics.html#EMISSIONS
- This is the EPA's official website for presenting emission data on Biodiesel.

US Dept of Energy's analysis of Biodiesel
(Biodiesel Performance, Costs, and Use)
http://www.eia.doe.gov/oiaf/analysispaper/biodiesel/
- Very objective view of Biodiesel. Discusses pro's & con's.

NREL 2004 Biodiesel Handling and Use Guidelines
http://www.nrel.gov/vehiclesandfuels/npbf/feature_guidelines.html
-- This document outlines the fact that emissions (especially NOx) are impacted by the type of oil that is used to produce Biodiesel. It has to do with how saturated the base feedstock is.
-- It also outlines several key items in relation to Biodiesel.

Now my opinion:
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Although Hybrids help to reduce several key emissions (because they use electric motors at idle and etc), they aren't the "end all" to the emission problem.  Biodiesel also reduces several of these key emissions, sometimes even exceeding them in a vehicle of same size & weight.

Another significant item of note is the fact that most diesel engines of similar size/weight have actually been known to get better gas mileage than even a comprable Hybrid. This means that size for size, a diesel consumes less fuel to run, and if run on Biodiesel, consumes no petroleum products to run.

Here's a nice site that show's benefits of different vehicles, compared side by side:
http://home.pacbell.net/tocho9/emission.htmlOn Umbra on hybrids vs. veggie-oil cars posted 4 years, 8 months ago 11 Responses