Rape seed oil as created by nature is an excellent fuel. It contains no sulphur which is an advantage regarding SO2 and particle emission. Rape seed oil is one example of tri-glycerides, which contains 11-12% oxygen in the molecule structure, which have an advantage for the combustion process. The oxygen content is considered to be the main reason for higher combustion efficiency compensating for less energy content compared to fossil diesel, and it is the reason for the reduction of visible smoke from the combustion.

To obtain good emission results, Pure Plant Oil should meet corresponding fuel standards for plant oil, and it should be combusted in suitable converted and optimised engines.

Germany is the dominating leader in research of Pure Plant Oil as fuel, and a quality standard has been developed, the so called RK-standard, which is developed specially for Raps Seed Oil. Other Plant Oil´s can have other characteristics influencing on the fuel properties.

As mentioned above, rape seed oil as created by nature is an excellent fuel, but can easily be spoiled by wrong processing, handling and storing. But it is quit easy to do it right.

Besides that combustion of PPO is carbon dioxide neutral, all other emission levels can be improved compared to fossil diesel. The only parameter which in general are unchanged is the NOx emission, because it is related to the combustion technology (high temperature and surplus air), and not directly to the fuel composition.

The following shows the emission test of a VW Golf 1.6 IDI and a VW LUPO 1.2 PDI 3L. The tests are made by professional emission test labortory. Nevertheless, the tests results are unoffcicial.

The results are all very fine, and shows that the vehicle after the conversion even could meet the EURO2 limits on PPO, but not on fossil diesel. All emissions are improved with PPO compared to fossil diesel(430ppm S)

The tests were made with a car with standard conversion, tested with both fossil diesel(b) and rape seed oil(c). For comparison a reference test on an unmodified car running on diesel was made. Unfortunately test b) and c) was carried out with 20% larger rolling resistance than the a), so a direct comparison is not possible without to consider the higher rolling resistance.

The test shows very fine results for particles (PM) of 86% of EURO3 limit, but the NOx emission exceeded the EURO3 limit by 80%. It corresponds with the reverse relation between PM and NOx emission. The test shows a consumption of 3.6 liters/100km on PPO and 3.8 liters/100km on diesel, but the test was by mistake carried out with 20% higher rolling resistance for the converted car (Fa(80km/h)=3,53kW) compared to the reference test with a non converted car (Fa(80km/h)=2,93kW). Therefore emissions and consumption was relatively higher for the converted car than for the reference car. If the numbers for consumption and CO2 emission is corrected with factor 2,93/3,53, both the consumption and CO2 emission matches the numbers for the reference car, so that the CO2 emission would be 83g/km and the consumption 3.0 liter/100km running on PPO.

See all test results