Safety first: Wear protective clothing and eyewear. This is a serious activity and it not recomended for a “weekend project”. This process is only for reference as to what skilled biodiesel makers would do.
Measure Free Fatty Acid content of your oil: Mix 1 ml oil with 10 ml Isopropyl alcohol = 2 drops phenolthalian solution (available in a hobby shop chemistry set suppliers). Drop-wise add 0.1% lye solution ( 1 gm lye in one liter water ) until the solution stays pink for 10 seconds. (20 drops = 1 ml) Record the milliliters of 0.1% lye solution used.
Methanol You will need 200 ml of methanol per liter of Hemp Seed oil. Methanol may be purchased as Drigas available at most automotive stores, read the label for methanol. Also Methanol is available from racing stores. Avoid hardware store methanol (wood alcohol) as it mat contain excessive water content.
Sodium Methoxide For each liter of hemp seed oil you need one gram of granular solid lye for each ml of 0.1% lye solution used in titration of free fatty acids plus 3.5 grams. Completely dissolve the proper amount of Lye in the methanol (Red Devil Lye can be purchased from the Grocery Store). This combined mixture makes sodium methoxide.
Mixer The type of mixer depends on the size of the batch. An electric drill and paint mixer on an extended shaft works well in a 5 gallon bucket.
Transesterfication: Once the lye catalyst is dissolved completely so that there is no sediment, then the oil may be added to the methanol lye mixture while mixing continuously. At first the mixture becomes thicker, then thinner as the reaction proceeds. Collect samples every 5 minutes with an eye dropper into a test tube or clear container. The Mixture will separate into a light top layer of bio diesel and a darker bottom layer of glycerin, soap and catalyst. Continued mixing 30 – 60 minutes until the yield remains constant. Then stop mixing. Go have lunch. When you come back it will have settled into two distinct layers. You have done it! Let the mixture settle for at least 8 hours. Pour off and save the bio diesel top layer into another container. A clear funnel bottomed container is helpful.
Rinsing: The raw Bio Diesel that you have just produced may have some catalyst, alcohol, and glycerin remaining which could cause engine problems, so for long term engine reliability this raw fuel should be rinsed with water. Gently at first then more vigorously rinse with water until the rinse water is clear and the pH of the rinse water is the same pH as the supply water. Settle, Decant.
Drying: Water in the bio Diesel makes cloudy so it must be carefully heated. At 100 C most of the water coalesces and falls to the bottom. This water must be completely removed from the bottom of the container before heating to higher temperature.
FAILURE TO REMOVE THIS WATER BEFORE FURTHER HEATING CAN CAUSE VIOLENT ERUPTION OF HOT LIQUID!
Once all water has been removed then heat the bio diesel to 300 f (150 c) to complete dryness. Cool, filter, and store bio diesel in a well marked dry closed container. 100% HEMP DIESEL FUEL (HEMP OIL METHYL ESTER – HOME FUEL)
This fuel may be mixed in any ratio with petroleum diesel. Dynamometer tests indicate full power output with up to 75% reduction in soot and particles. No engine modification is needed to burn bio diesel fuel.