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 used with both fresh and used oils.
1. Use the oil just as it is-- generally called SVO fuel (straight grease);
2. Mix it with kerosene (paraffin) or petroleum diesel fuel, or with biodiesel, or mix it with a solvent, or with fuel;
3. Convert it to biodiesel.
The first 2 methods sound most convenient, but, as so typically in life, it's not quite that basic.
1. Mixing it
Vegetable oil is much more viscous (thicker) than either petro-diesel or biodiesel. The purpose of blending it or mixing it with other fuels is to reduce the viscosity to make it thinner so that it streams more freely through the fuel system into the combustion chamber.
If you're mixing veg-oil with petroleum diesel or kerosene (exact same as # 1 diesel) you're still using fossilfuel-- cleaner than the majority of, however still not clean enough, many would say. Still, for every single gallon of
grease you use, that's one gallon of fossil-fuel saved, and that much less climate-changing carbon in the atmosphere.
People utilize different blends, ranging from 10% veggie oil and 90% petro-diesel to 90% grease and 10% petro-diesel. Some individuals just utilize it that method, begin up and go, without pre-heating it (that makes veg-oil much thinner), or even utilize pure veggie oil without pre-heating it, which would make it much thinner.
You might get away with it with an older 5-cylinder IDI diesel, which is a very tough and tolerant motor-- it won't like it however you probably won't eliminate it. Otherwise, it's not wise.
To do it appropriately you'll require what totals up to an SVO system with fuel pre-heating anyhow, ideally using pure petro-diesel or biodiesel for starts and stops. (See next.) In which case there's no need for the blends.
Blends with various solvents and/or with unleaded gas are "experimental at best", little or absolutely nothing is known about their impacts on the combustion attributes of the fuel or their long-lasting effects on the engine.
Higher viscosity is not the only issue with using grease as fuel. Veg-oil has different chemical properties and combustion qualities from the petroleum diesel fuel for which diesel motor and their fuel systems are developed.
Diesel motor are modern makers with really exact fuel requirements, particularly the more modern, cleaner-burning diesels (see The TDI-SVO controversy).
They're difficult but they'll only take so much abuse. There's no guarantee of it, but using a mix of as much as 20% veg-oil of excellent quality is said to be safe enough for older diesels, specifically in summer.
Otherwise utilizing veg-oil fuel needs either an expert SVO solution or biodiesel. Mixes and blends are typically a bad compromise. But blends do have an advantage in cold weather condition.
Just like biodiesel, some kerosene or winterised petro-diesel fuel combined with straight veggie oil reduces the temperature at which it starts to gel. (See Using biodiesel in winter) More about fuel mixing and blends.