Only the best technology and quality vegetable oil offers real security!

Pure Plant Oil (PPO) is a valuable, natural source of energy which is produced and used climatically friendly and from regenerative sources. PPO possesses an incredible chemical similarity to diesel and, following a simple conversion process, can be used to fuel most standard diesel engines. Along with the qualitatively variable properties such as phosphorus or water content, certain fixed (even characteristical) properties determine the suitability of a given oil for technical application.

Although the energy content of PPO is somewhat lower than diesel, it has a higher density. As the injection pump always supplies a fixed volume, there is no change in performance of consumption in the engine. The flow reaction (viscosity) improves greatly upon warming and the engine’s auxiliary parts are able to use PPO exactly the same way they use diesel.

PPO even offers technical advantages: it is a better lubricant than diesel and, in its normal state, non- flammable. PPO reacts in the motor similarly to diesel: it is pumped and set under pressure, it is atomised at the injection pump, the drops are heated and vaporised (the temperature in the cylinder of a diesel motor just before combustion is between 500 and 700°C), the vapours are ignited and combustion takes place the same way as with diesel.

Certain adaptations have to be made to the cycle, however, and the system is, therefore, technically fitted with a so called two tank system which allows the engine to start up on diesel and also regulated the fuel flow to reach the optimal performance under all driving conditions. Single tank solutions are a nice idea, however, they offer insufficient security for commercial fleets as many court cases have already proven.

Quality requirements in the field of stationary engine applications (CHPP), are much higher for both machines and fuel than in mobile applications as the engine in a CHPP has a much more constant running time than that which can expected from a vehicle engine. This consistency of operation, however, is beneficial to the combustion process and technical improvements to the motor control are possible. Auxiliary units such as Fuel in feed, storage units or heat exchanger connections need to be adapted to ensure optimal economic efficiency. As with all matters, the use of PPO as a fuel also requires effective risk management. Making sure you obtain reliant and professional advice and assistance can ensure engine damage as followed is avoided.

Dangers to the engine

Diesel engines are constructed with the use of diesel fuelling in mind. There are, therefore, several aspects that require consideration when operating with PPO fuels: - PPO burns badly and incompletely when the engine is still cold. If no conversion unit is added, then your engine will only operate with a diesel fuel mix. - PPO also burns badly at low RPM. PPO then mixes with motor oil and this will, in time, result in damage to the motor. - PPO is a natural product and naturally mistakes can be made in the production process. Undesired particles result in deposition, corrosion and coking. Engine damage will result in time here to if low quality PPOs is used. It is, therefore, important to make sure that a high quality fuel and a seasoned conversion technology are used in order to ensure a long working life for your engine. These risks are manageable, as our insurance cover option proves, ask us directly for details!

Motor oil polymerisation

Motor oil polymerisation is when motor oil congeals to become a tar-like mass.
Motor oil polymerisation occurs where motor oil condenses almost to the state of a pulp. A high mix of motor oil & PPO is often the cause and the catalyst for polymerisation. The mixing of PPO and motor oil occurs especially fast where the engine is still cold or at low RPM. Although all motor oils are naturally absorption tolerant, a mix of max. 6% should not be exceeded. (Oilanalyse!)

In addition to this, the chemical composition of PPOs themselves can be conducive to polymerisation due to: - many free fatty acids in the PPO (acid value, FFA) - many free double bonds (e.g. C18:1,C18:2;C18:3, …) , i.e. high Iodine levels. The composition of a PPO depends on the type of PPO used. Unfortunately many traders offer low priced…and with it low quality fuel on the marketplace. Take care when choosing your PPO-supplier! Conformity with the DIN norm is not necessarily a warranty for a quality product!

Coking of combustion chamber

Coking occurs when residue from the combustion process builds up in the combustion chamber. Coking can lead to malfunctions in diverse engine parts and, therefore, needs to be avoided at all costs.

A build up of residue can, for example, result from:
- a high phosphorus content in the PPO
- a high level of total oil impurity
- worn injection nozzles

State of injection nozzles

In order to obtain an efficient combustion with PPO, it is necessary to ensure that the fuel is converted into a fine spray. Worn injection nozzles are not able to generate the spray required to 100% and, therefore, promote the mix of PPO and motor oil which, in turn, leads to coking in the combustion chamber. Please make sure that the injection nozzles are replaced on a regular basis. For commercial vehicles, we recommend a replacement every 500.000 km.

Motor oil analysis

In order to ensure the state of the engine and the motor oil is properly controlled, we recommend a regular motor oil analysis. This analysis delivers the data required to determine the actual state of the engine and oil. Analysis kits are available from about €40,- for example under:

- www.wearcheck.de

- www.asg-analytik.de
NEED’s own daughter company NEED BTT develops and manufactures high quality conversion kits for commercial vehicle application. Please contact us for a quote – on request including insurance and financing!