Make your own Biodiesel Part 1
There are at least three methods to run a diesel engine on biofuel utilizing veggie oils, animal fats or both. All three are utilized with both fresh and secondhand oils.
1. Use the oil just as it is-- typically called SVO fuel (straight vegetable oil);
2. Mix it with kerosene (paraffin) or petroleum diesel fuel, or with biodiesel, or blend it with a solvent, or with fuel;
3. Convert it to biodiesel.
The very first 2 methods sound simplest, but, as so typically in life, it's not rather that easy.
1. Mixing it
Grease is a lot more viscous (thicker) than either petro-diesel or biodiesel. The function of mixing it or blending it with other fuels is to decrease the viscosity to make it thinner so that it flows more easily through the fuel system into the combustion chamber.
If you're mixing veg-oil with petroleum diesel or kerosene (very same as # 1 diesel) you're still utilizing fossilfuel-- cleaner than most, but still unclean enough, many would say. Still, for every single gallon of
vegetable oil you utilize, that's one gallon of fossil-fuel conserved, which much less climate-changing carbon in the atmosphere.
People utilize different mixes, ranging from 10% veggie oil and 90% petro-diesel to 90% vegetable oil and 10% petro-diesel. Some people simply utilize it that method, launch and go, without pre-heating it (which makes much thinner), and even use pure grease without pre-heating it, which would make it much thinner.
You may get away with it with an older Mercedes 5-cylinder IDI diesel, which is a very difficult and tolerant motor-- it won't like it however you probably won't eliminate it. Otherwise, it's not smart.
To do it correctly you'll need what amounts to an SVO system with fuel pre-heating anyway, ideally using pure petro-diesel or biodiesel for starts and stops. (See next.) In which case there's no need for the mixes.
Blends with various solvents and/or with unleaded fuel are "experimental at best", little or absolutely nothing is known about their effects on the combustion characteristics of the fuel or their long-term results on the engine.
Higher viscosity is not the only problem with utilizing vegetable oil as fuel. Veg-oil has various chemical properties and combustion characteristics from the petroleum diesel fuel for which diesel engines and their fuel systems are created.
Diesel engines are modern machines with really exact fuel requirements, especially the more contemporary, cleaner-burning diesels (see The TDI-SVO controversy).
They're hard but they'll just take a lot abuse. There's no assurance of it, but utilizing a blend of as much as 20% veg-oil of good quality is said to be safe enough for older diesels, particularly in summer.
Otherwise utilizing veg-oil fuel requires either an expert SVO service or biodiesel. Mixes and blends are normally a poor compromise. But mixes do have a benefit in cold weather condition.
Similar to biodiesel, some kerosene or winterised petro-diesel fuel combined with straight grease reduces the temperature at which it begins to gel. (See Using biodiesel in winter) More about fuel mixing and blends.