It is important to separate water from oil if you are making biodiesel or running your car on waste vegetable oil. The following tips are also ideal for fuel or automotive oil, even though it is not recommended to heat them.
In order to achieve the best result, the drum with the oil and water should be untouched and kept at above 60°F. Normally, both liquid should separate with the lighter one going to the top while the heavier one goes to the bottom. It is important to note that vegetable oil solidifies at low temperature thereby inhibiting the natural separation. Complete oil and water separation may take place at 80°F while it may take several weeks if the temperature is maintained at 40°F. Motor and fuel oils do not solidify like vegetable oil and should be separated from water at lower temperatures.
Furthermore, if the temperature is too low for satisfactory separation, you should heat the barrel and/or its contents or transfer the mixture a bucketful at a time to a container in a warm location. You can make use of a commercial immersion heater to heat the mixture in the drum so that proper separation will be enhanced. You should avoid heating the motor or fuel oil because it is dangerous to do so.
In order to remove the separated oil, you will need to suction it from the top into another container at ground level. You can get a small pump which attaches to an electric drill and transfers liquids by the means of two hoses, at hardware stores everywhere. However, you should stop pumping it before getting to the water level underneath.
On the other hand, if you want to remove the water from the drum and leave oil behind, you will need a pump and a hose that will get to the bottom of the drum. A siphon is useful in moving water from a higher level to lower level. However, you should be very careful as the pumping progresses so that when the water is gone, you don’t start pumping the oil.
You should endeavor to make use of equipment in good shape so that the process could be hitch-free. You should give no room for any mistake because it can lead to getting a bad result which is not good for your polluted liquid, in your desire to make it pure.