What Is Biodiesel ?

Bio-diesel is the ‘green’ fuel for the future.

It is a truly sustainable environmentally friendly biofuel and generates no harmful emissions. It can be used in standard diesel engines without modifications being required. Its ingredients are waste cooking oils and fats but it can also be made from organic oil, rapeseed oil, Soya or other vegetable oils.

In chemical terms, Bio-diesel consists of long chain fatty acids derived from renewable lipid sources. The lipid (vegetable oil, animal fat or, as in our process, cooking oil) is treated with a light alcohol in the presence of a catalyst. This gives two products, glycerine and Bio-diesel, both of which are bio-degradable and non-hazardous.

When used in diesel fuel engines, Biodiesel performance is similar to petroleum-based diesel fuel. Its higher viscosity can be reduced by a variety of relatively simple processes giving better atomisation in the injector system and an improved spray pattern.

Fleet managers have found that Biodiesel gives similar operating performance to conventional diesel fuel and requires no changes in facilities. This gives it a major advantage over other possible 'alternative' fuels.

The waste cooking oil is readily available from our sister company, Oilco Cooking oils. About 85% of the output is Bio-diesel and the remaining 15% is glycerine. Naturally occurring micro-organisms attack and degrade glycerine with no harmful effect. This by-product can therefore be disposed of without requiring complex 'decontamination' systems or long-distance transport to specialist disposal premises.

Is It Safe ?

Many tests have been carried out on various aspects of the safety of Bio-diesel and the key points that emerged were :

Its toxicity in water is far lower than the toxicity of petroleum-based diesel fuel by a factor of between 15 and 200.

Its flash point is much higher than that of petroleum-based diesel fuel and it is therefore safer to store and to use. The air/fuel vapour produced by Biodiesel is not explosive.

There is a major reduction of unburned hydrocarbons, carbon monoxide, and particles (in particular the sulphate fraction is eliminated and the solid hydrocarbon fraction is greatly reduced). The nitrogen oxide levels are not significantly changed.

Who Gains ?

We all do.

Indirectly we will all benefit from any move towards a fully sustainable non-polluting biofuel such as Biodiesel rather than using the ever-decreasing fossil fuel resources. This combines with the benefits of nil emissions, and a useful and bio-degradable by-product in the production process. It has been shown that Bio-diesel has a far shorter bio-degradation time than standard diesel fuel (and that a 20% admixture of Bio-diesel significantly reduces the degradation time for standard diesel).

Direct gains will occur for Companies who use Biodiesel as the nil emission level will reduce the tax payable on Company vehicles and many tests have shown no difference in performance. After all, the first diesel engine was engineered to be run on peanut oil and not mineral oil. Most car manufacturers recognise Biodiesel as a ‘real’ fuel and will honour warranties as a result.

Another direct gain will come for businesses needing to dispose of waste cooking oil. Most such waste oil is currently recycled, under strict controls, in animal feeds and we use about 35,000 litres a week for making Bio-Diesel. There is a plan to ban the use of waste oil in animal feeds and, if this occurs, catering and other industries will be looking for alternative ways of disposing of their waste. It is therefore likely that our usage will increase to over 100,000 litres a week.

We at Greenstar Biofuels feel that the government should themselves be introducing Bio-diesel into the market place within the next few years with a target of 2-3% of total fuel used in the UK, increasing to 10% in ten years. Quite apart from the cost savings to the consumer there would be a triple environmental advantage : lower emission levels, reduced use of the limited petroleum resources and an efficient disposal system for a waste product. Taken as a whole this has to be a good political plus point !

Who Loses ?

The taxman. The duty on Bio-diesel is, at the moment, 27p per litre compared to 47p for diesel. This means that the overall cost should be less by a few pence per litre

Biodiesel Emissions

Biodiesel is the first and only alternative fuel to have a complete evaluation of emission results and potential health effects submitted to the U.S. Environmental Protection Agency (EPA) under the Clean Air Act Section 211(b). These programs include the most stringent emissions testing protocols ever required by EPA for certification of fuels or fuel additives. The data gathered complete the most thorough inventory of the environmental and human health effects attributes that current technology will allow.

EPA has surveyed the large body of biodiesel emissions studies and averaged the Health Effects testing results with other major studies. The results are seen in the table below.

Average biodiesel emissions compared to conventional diesel according to EPA

Emission type

B100

B20

Regulated:

Total Unburned Hydrocarbons
-67%

-20%

Carbon Monoxide
-48%

-12%

Particulate Matter
-47%

-12%

Nox
+10%

+2%

Non-Regulated

Sulphates
-100%

-20%*

PAH (polycyclic Aromatic Hydrocarbons)**
-80%

-13%

nPAH (Nitrated PAH's)**
-90%

-50%***

Ozone potential of specialis
-50%

-10%

* Estimated from B100 result
** Average reduction across all compounds measured
*** 2-nitroflourine results were within test method variability

The overall ozone (smog) forming potential of biodiesel is less than diesel fuel.
The ozone forming potential of the speciated hydrocarbon emissions was 67 percent less than that measured for diesel fuel.

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

Criteria pollutants are reduced with biodiesel use.
Tests show the use of biodiesel in diesel engines results in substantial reductions of unburned
hydrocarbons, carbon monoxide, and par+iculate matter. Emissions of nitrogen oxides stay the same or are slightly increased.

Carbon Monoxide -
The exhaust emissions of carbon monoxide (a poisonous gas) from biodiesel are on average 47 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 par+iculate matter from biodiesel are about 47 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) are on average 67 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 increase on average by 10 percent. However, biodiesel's lack of sulfur allows the use of NOx control technologies that cannot be used with conventional diesel. Additionally, some companies have successfully developed additives to reduce Nox emissions in biodiesel blends.

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.