Make Your Own Biodiesel Part 1

There are at least 3 ways to run a diesel motor on biofuel using veggie oils, animal fats or both. All three are used with both fresh and used oils.


1. Use the oil just as it is-- usually 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 gasoline;


3. Convert it to biodiesel.


The very first two methods sound simplest, but, as so often in life, it's not rather that simple.


1. Mixing it


Vegetable oil is a lot more thick (thicker) than either petro-diesel or biodiesel. The purpose of blending it or blending it with other fuels is to lower the viscosity to make it thinner so that it streams more easily through the fuel system into the combustion chamber.


If you're mixing veg-oil with petroleum diesel or kerosene (same as # 1 diesel) you're still using fossilfuel-- cleaner than many, but still not tidy enough, lots of would state. Still, for every gallon of


veggie oil you use, that's one gallon of fossil-fuel conserved, and that much less in the environment.


People utilize numerous mixes, ranging from 10% veggie oil and 90% petro-diesel to 90% vegetable oil and 10% petro-diesel. Some people just use it that method, begin up and go, without pre-heating it (which makes veg-oil much thinner), or even use pure vegetable oil without pre-heating it, which would make it much thinner.


You might get away with it with an older Mercedes 5-cylinder IDI diesel, which is a really hard and tolerant motor-- it won't like it but you probably won't eliminate it. Otherwise, it's not wise.


To do it appropriately you'll need what totals up to an SVO system with fuel pre-heating anyway, preferably 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 gas are "experimental at best", little or nothing is understood about their results on the combustion qualities of the fuel or their long-term results on the engine.


Higher viscosity is not the only problem with using grease as fuel. Veg-oil has different chemical homes and combustion attributes from the petroleum diesel fuel for which diesel motor and their fuel systems are designed.


Diesel motor are high-tech makers with very exact fuel requirements, particularly the more modern, cleaner-burning diesels (see The TDI-SVO debate).


They are difficult however they'll just take so much abuse. There's no guarantee of it, however using a blend of approximately 20% veg-oil of good quality is said to be safe enough for older diesels, specifically in summer.


Otherwise using veg-oil fuel needs either an expert SVO option or biodiesel. Mixes and blends are generally a bad compromise. But mixes do have an advantage in cold weather condition.


Just like biodiesel, some kerosene or winterised petro-diesel fuel combined with straight grease lowers the temperature at which it begins to gel. (See Using biodiesel in winter) More about fuel mixing and blends.