Biofuel

[kandrathe]

Due to the higher water and free fatty acid content in used frying oil, most literature that I came across suggests that you use the slower (but not a big deal for batch processes run at home) acid catalyzed process rather than the faster (but less flexible since it doesn't like water) base catalyzed process if you are using used frying oils.

It seems the water removal is a step in heating the oil to 120C for 10 minutes. If I were going to do this, first I would check out sources of Sulfuric Acid, NAOH, and KOH to determine which chemical was cheapest and most readily accessible. Then, try the acid technique in a small one liter batch, and the alkali technique in a one liter batch to compare processing difficulties. Based on the effort involved and the materials costs then determine if you want to do it, and then if you do, which technique would work best for you. Also, I would be concerned about regulated vapor emissions at the county and state level. There may be a permit process to have a bio-diesel production facility, and depending on the scale of your operation they might require emissions monitoring. At least if the authorities know about you, they won't suspect you of manufacturing Triacetone Triperoxide.

Googling around I found;
Cole-Parmer - 98% Sulferic Acid 2.5l for $70.80
Organic Creations - Potassium Hydroxide (KOH) 5 Pounds for $26.25
SpecialClay -- Sodium Hydroxide - Lye - Caustic Soda - 15 lbs for $70

Then, MEAT can calculate the cost of the materials for the volume produced. If using the acid technique you would need a catalyst chamber that will withstand both the acid and heat.

Here is a link to a bio-diesel project done for a course in Agricultural and Biosystems Engineering. Although some of the language is obviously wrong, like "Water should be sprinkled gently on top of the water; the water droplets will collect at the bottom of the tank for removal." It is probably supposed to read "sprinkled on top of the mixture". It does give some analysis of costs;



If you assume as I have that your WVO is free, and you won't bill yourself for labor then your price per gallon will be determined primarily from the cost of the methanol you use in transesterification. So, also as the demand for energy (incl. bio-diesel, natural gas, etc) increases, so will the price of methanol. It is already up substantially from one year ago, so you might see methanol up near the $2.00 to $3.00 per gallon mark. "However, the spot-market slide could be temporary as market analysts still project a third quarter spot-price average of delivered product at $1.97/gallon—as compared with $1.89 in the second quarter. A key issue is the inflation attacking raw materials and energy, especially natural gas, used to produce methanol." -- Purchasing.com I can see based on the cost that it may be worthwhile to reclaim the unreacted methanol once you've mastered the production process.

Edit: Also, found Global Outlook on Methanol and Derivatives 2000-2012. It looks bleak for the US.