BIODIESEL FUEL IS BETTER FOR YOUR LUNGS

Biodiesel is America's homegrown, clean air alternative to imported petroleum.

Biodiesel can be produced from domestic renewable resources including vegetable oils and recycled restaurant grease. Pure biodiesel contains no petroleum, but it can be blended at any level with petroleum diesel to create a biodiesel blend. It can be used in compression-ignition (diesel) engines with no major modifications. Biodiesel is simple to use, biodegradable, nontoxic, and essentially free of sulphur and aromatics.

Virgin vegetable oil used for the manufacture of biodiesel can be harvested from many oil feedstock plants like soybeans, sunflower seeds, rape seeds, palm oil and even some types of algae. Recycled vegetable oil from local restaurants and other used sources are also a useful reservoir of renewable fuel for diesel engines as approximately 4.5 billion gallons per year of used vegetable oil is available in the USA.

The concept of using vegetable oil as a fuel dates back to 1895 when Dr. Rudolf Diesel developed the first diesel engine to run on vegetable oil. He demonstrated his engine at the World Exhibition in Paris in 1900 and described an experiment using peanut oil as fuel in his engine.

The overall smog forming potential from biodiesel hydrocarbon emissions is nearly 50% less than that measured for ordinary diesel fuel.

Biodiesel fuel reduces emissions associated with smog, acid rain,
global warming and airborne cancers

The use of biodiesel results in emissions which contain substantially reduced levels of chemicals associated with smog formation, sulphur associated with acid rain, greenhouse gases related to global warming, and carcinogenic diesel particulate matter including soot, arsenic, benzene, and formaldehyde. 

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

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

Biodiesel reduces the health risks associated with petroleum diesel. Biodiesel emissions show decreased levels of polycyclic aromatic hydrocarbons (PAH) and nitrated polycyclic aromatic hydrocarbons (nPAH), which have been identified as potential cancer causing compounds. In Health Effects 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, with 2-nitrofluorene and 1- nitropyrene reduced by 90 percent, and the rest of the nPAH compounds reduced to only trace levels.

Repeated studies confirm that the use of biodiesel in a conventional diesel engine results in substantial reduction of unburned hydrocarbons, carbon monoxide, and particulate matter. Emissions of nitrogen oxides are either slightly reduced or slightly increased depending on the duty cycle of the engine and testing methods employed and can be dramatically reduced with the use of pre-combustion catalysts and EPA verified traps.

Can biodiesel help mitigate “global warming”? Biodiesel is the best greenhouse gas mitigation strategy for today’s medium and heavyduty vehicles. A 1998 biodiesel lifecycle study, jointly sponsored by the U.S. Departmentof Energy and the U.S. Department of Agriculture, concluded biodiesel reduces netcarbon dioxide emissions by 78 percent compared to petroleum diesel. This is due to biodiesel’s closed carbon cycle. The CO² released into the atmosphere when biodiesel is burned is recycled by growing plants, which are later processed into fuel.

Particulate emissions from conventional diesel engines are generally divided into three components and are in varying degree responsible for the black cloud emanating from a diesel powered vehicles exhaust tail pipe.

The first component, and the one most closely related to the visible smoke often associated with diesel exhaust, is the carbonaceous material. This material is composed of sub-micron sized carbon particles which are formed during the diesel combustion process. It is especially prevalent under conditions when the fuel-air ratio is overly rich, such as full acceleration, maximum power or on start up.

The second component is hydrocarbon material which is absorbed on the carbon particles, commonly referred to as the soluble fraction. A portion of this material results from incomplete combustion of the fuel and the remainder is derived from engine lube oil that passes by the piston oil rings. The third particulate component is comprised of sulfates and bound water, with the amount of material being directly related to the fuel's sulfur content. The US has comparably high sulfur content in most of its petrochemical diesel fuels, so diesel engine use in America is more affected by this problem than most other countries.

The use of biodiesel decreases the solid carbon fraction of particulate matter as the increased amount of oxygen present in biodiesel enables a more complete combustion process. Biodiesel eliminates the sulfate fraction problem associated with petroleum based diesel as there is no sulfur in biodiesel, sulphur dioxide is the major component of acid rain. In addition to reducing the overall levels of pollutants and carbon, the compounds that are prevalent in biodiesel and petroleum based diesel fuel exhaust are different. Research conducted by Southwest Research Institute on a Cummins N14 engine indicates that the biodiesel exhaust has a less harmful impact on human health than petroleum diesel. Biodiesel emissions have decreased the levels of all largest polycyclic aromatic hydrocarbons (PAH) and nitrated PAH compounds were reduced by 75-85%.

Emission reduction benefits of Biodiesel

Biodiesel is nontoxic and poses little or no health risk to humans. Vehicles that run on biodiesel emit less sulfur dioxide (SO2), particulate matter (soot), carbon-dioxide (CO2), with fewer heavy Hydrocarbons (HC) and Polycyclic Aromatic Hydrocarbons (PAH). Biodiesel does not contain sulfur so it will not contribute to sulfur dioxide emissions that result in acid rain. Tests have shown that the cancer-causing potential of particulate matter from pure biodiesel is about 94% less than that of regular diesel.

Biodiesel will not poison exhaust catalysts like sulfur laden diesel and it actually improves the efficiency of oxidative catalysts. The chart below shows some of the major emission gains that can be achieved with Catalytic converters, that are not possible using the sulfur laden diesel currently available in the US fuel supply chain.

Emission Comparison compared to diesel fuel per Mile for a Passenger Car             
        ^*Lifecycle CO2 Emissions

What about NOx emissions?

Using Biodiesel could remove 24,000 tons of NOx from the air in just in Texas EVERY year.

If an additized B20 Biodiesel blend were used throughout the entire Texas diesel fuel supply, the reductions in statewide NOx emissions would be impressive. As a bonus, the biggest gains would come in the most heavily trafficked areas like DFW and Houston, which are the most ozone blighted non-attainment areas of the state. Nationwide, blending biodiesel in with the nation's diesel fuel supply will enable dramatic reductions in NOx emissions, without the need to retro-fit any vehicles or fueling infrastructure.  

Biodiesel’s lack of sulfur also allows the use of NOx control technologies that cannot be used with conventional diesel fuels such as catalysts. The use of Biodiesel actually enhances the capability of catalyzed particulate traps to reduce NOx emissions.

There is some data that suggests that NOx reductions actually result in increasing ozone levels as demonstrated by what is called the "weekend effect". This weekend effect is experienced most markedly in California where ozone levels increase on the weekend when you would expect the ozone levels to decrease due to the reduction in vehicle traffic flow and industrial activity. There is a considerable weight of argument that says that particulate matter is much more responsible for ground level ozone than NOx.

There are some proponents suggesting that we might try increasing NOx emissions in an effort to reduce ozone levels. The theory goes that as the level of NOx is increased, this makes more reaction material available and enables the ozone to more readily create Nitrogen Dioxide, which would in turn reduce the level of ozone. This idea is obviously still a matter of considerable debate and is not the consensus view of the majority of pollution control experts. 

The long and short of all this debate is that we need to reduce the amount of fossil fuel we burn if we are to have any hope of cleaning up the air in America. Biodiesel allows us to do this today, without stopping the trucks running that keep our economy moving.

Hydrocarbons -- The exhaust emissions of total hydrocarbons (a contributing factor in the localized formation of smog and ozone) are on average 67 percent lower for biodiesel than diesel fuel.