Biodiesel processors, available for commercial and home use, are machines that make biodiesel fuel out of vegetable oil and animal fat. They use the same basic process that large plants use: mixing oil or fat with methanol and getting fuel through the chemical process of transesterfication. With such a processor in your home you could soon be looking at substantial savings. After all, biodiesel fuel costs about seventy cents per gallon. Subtract the cost of gasoline per gallon at your local gas station and multiply that by the approximate number of gallons of fuel you buy in a year. That's how much money you stand to save. And in most cases, biodiesel processors are easy to maintain. In short, they might be pricey at first, but most people who buy one feel that they are well worth the upfront investment.

Biodiesel processors can be made out of polypropylene or polyethylene. Plastic is very economical, and surprisingly efficient as well, but it does not offer too much protection against fire, and many of the materials used in biofuel manufacture are highly flammable. Steel is a common material as well. It corrodes in time, however, and it can also chemically warp the biodiesel fuel somewhat in the process, making it a little weaker and a little less effective. On the other hand, steel is strong and sturdy. And some processors use a variety of materials, including steel and iron. Stainless steel might be the best option, because it is extremely durable and also will not affect or alter the fuel being made in any way. However, stainless steel is also the most expensive option and is not usually seen in privately-owned biodiesel processors.

Biodiesel processors might come in a variety of shapes and sizes, though they usually all have a rounded bottom. They generally all have the same parts, too. There's a pump. There's some sort of heating device that makes sure the machine is hot enough to allow the chemical reactions to take place. There is an in-feed tank where you pour the vegetable oil in. There's a glass on the side where you can see how much oil is inside the processor. There's a tank for keeping the methanol, an automatic-mixing apparatus to mix the methanol and oil together, another device that automatically removes the glycerin after it has been separated from the methyl ethers in the oil, a chamber that washes the biodiesel fuel, a tank that stores the biodiesel until you are ready to remove it, and an external vent that relieves any pressure building up inside of the processor. There are also various kinds of pipes and valves that you can buy; these pipes and valves come in a wide variety of price ranges. As long as every part of the machine is in good working order, the total time of the oil-to-fuel transformation should be about two hours.

One part of the biodiesel processor deserves particular attention, and that's the biodiesel reactor. (Some people refer to the reactor itself as the processor.) It's where the action happens.