If you're tired of choosing between high winter heating bills and bundling up in a hat and gloves for a trip to the restroom, you may be investigating some cheaper sources of heat for your home. Unfortunately, many of the systems with the lowest ongoing costs (like exterior wood stoves and geothermal heat pumps) are expensive to install, and you may find it easier to pay a high utility bill each month than shell out thousands (or tens of thousands) for a new heating system. However, if your home is currently being heated by an oil-burning furnace, you may be able to inexpensively manufacture your own biodiesel from recycled cooking oil and begin using it in place of your crude-based heating oil. Read on to learn more about making your own clean-burning, inexpensive fuel.
How can you get the oil used to make biodiesel?
Biodiesel has few ingredients -- just vegetable oil, an alcohol (like ethanol or methanol) and lye. During the conversion process, caustic lye is used to break up the triglyceride chains of each vegetable oil molecule. After the glycerin created from this process is drained off, you'll be left with pure biodiesel.
You should be able to purchase both the lye and methanol at a home supply store, along with the containers and tubing you'll need to set up your brewing lab. While vegetable oil can be much less expensive than heating oil, unless you run a restaurant or other business that generates a great deal of waste oil, you may not have easy access to all the fuel you'll need to get started. You may also be reluctant to buy fresh vegetable oil for this conversion process, especially when using waste oil can allow you to make your own biodiesel for around 80 cents per gallon.
However, many fast-food restaurants already pay a weekly or monthly fee to recycle their old cooking oil. In many cases, you may be able to come to a win-win agreement with area restaurant owners -- you'll take a portion of their waste oil off their hands without charging a fee, and they'll save money on recycling costs. To do this, you'll just need a pickup truck and a large plastic or PVC holding container to transport this oil back to your home. You can also reach out to an oil recycling and grease collection company like Tierra Environmental & Industrial Services to see if they have any advice for collecting old oil.
What will you need to do to begin brewing?
You'll first need to filter out any food particles or other debris from your waste oil to ensure the final product is as pure as possible. This can usually be accomplished with a simple mesh strainer attached to the lid of the holding container. If this oil still looks cloudy (which can indicate small particles floating around), let it sit overnight to see if this sediment will settle to the bottom, allowing you to drain off the clear oil.
You'll then need a large plastic or steel holding tank for your oil and a smaller tank for the methanol and lye mixture. While plastic tanks can be purchased at a relatively low price, some enterprising homeowners have even been able to convert an old hot water heater for this purpose.
You'll then want to run some flexible tubing from the methanol tank to the oil tank, ensuring that the tubing is firmly secured at both ends with an O-ring or similar device. This tubing will allow you to send methanol and lye from the holding tank to the oil tank for mixing or processing without subjecting you to potentially toxic fumes or caustic chemicals.
Once you've manually sent the methanol to mix with the oil mixing, the rest of the job will be accomplished via the natural chemical reactions that remove glycerin molecules from the vegetable oil. You may wish to keep your biodiesel in the oil holding tank until you're ready to use it, or can put it in a separate storage tank to allow you to continue brewing additional batches.