WVO or Waste Vegetable Oil
There is much information on vegetable oil how it is made, what it is use for from the time it is process to the time it is considered a waste product. Usually at this point it becomes a waste product is when it leaves the fryer. But is that the end of its serviceable life some say no there is an increasing interest to use this waste oil as fuel, biodiesel and biofuel.
How is waste vegetable oil or WVO made into fuel? First all this needs to be done at room temperature 70 degrees F you need sodium hydroxide lye methanol Heet and vegetable oil. You add these three ingredients together in the correct quantities and mix them until they are completely blended. At this point you let the mixture settle it will separate into layers the bottom layer will be glycerin and the top layer will be Biodiesel.
The process above was with clean oil but what about the oils and grease from fryers grills etc. what to do when you have old oil that isn’t very clean. Well at the start of the process you need to filter the oil there are many ways to do this Bag filters are the easiest cheapest and slowest processing tool that you have other than strait settling to process WVO . Oil will run through a 100 micron filter bag at 2-5 gallons per minute however, if the oil is dirty or just creamy the flow rate will deteriorate rapidly. Pre-heating the oil helps as does larger/longer filter bags. My advice is to only use filter bags after settling. Cartridge WVO filters, tee strainers ECT, should be used only with heated oil or heating of the filter. Waxy precipitates in cool oil quickly clog cartridge filters and no amount of pressure will resolve this issue.Reserve cartridge filters for final polishing filtering at transfer into the vehicle or very low volume emergency use. Any mechanical cartridge filter will require an amount of pressure to work, finding an appropriate pump, plumbing and pressure relief system can be difficult and large spills are possible.
Another way is to use what I call Forced Settling WVO centrifuges can clean WVO to sub micron levels as well as removing heavier liquid contaminants such as water.If you are looking at having to deal with hundreds of gallons or more a centrifuge is your only solution.
You probably don’t stop to think about it, but all fuels have a shelf life that depends on their chemical composition and storage conditions. he chemical stability of biodiesel depends on the oil from which it was derived from. Biodiesel from oils that naturally contain the antioxidant tocopherol or vitamin E.g., rapeseed oil) remain usable longer than biodiesel from other types of vegetable oils. Stability can be deminished after 10 days and the fuel may be unusable after 2 months. Temperature also affects fuel stability in that excessive temperatures may denature the fuel.