WFU Biofuels

Wake Forest students, faculty, staff and associates making and testing vegetable-oil based fuels.

Friday, October 14, 2005

Shaman says: make a hexane still

Yesterday afternoon the Shaman, the Sorcerer's Apprentice, and I were talking about producing BioD from virgin oil rather than waste. Now, we're not looking to upset the apple cart on the plans for the bigger reactor, but we were doing some brainstorming. In particular, we were looking at the economics of making biodiesel from oil that we grow cooperatively with local farmers.

The oil yield per bushel (and per acre) varies a lot among crops, and the ways that oil is extracted varies a lot, from mortar and pestle, to mechanical (ram and screw presses) all the way up to the solvent methods that the big-boys use. Looking at straight oil extraction, it doesn't look like traditional crops are going to be cost effective unless you factor in the profit gained by using the meal. Home-pressed sunflower oil comes out to >$10/gallon, and soybean oil comes out to ~$4.50 a gallon, the latter just figured on yield per acre and the cost that an acre of soybeans can bring. Canola seed and other oil crops might be able to do better, particularly if you can find a way to use the meal (like feeding it to my pigs or cows).

So, where does hexane play into all of this? Well, the Shaman was talking about making a hexane still to extract the oil out of flaked soybeans, or whatever other crop we use. Hexane is cheap, and super flammable (two qualities that endear it to pyros) and also gives a super efficient extraction of the oil. And, the meal can be used afterwards. Hexane in your food, you gasp? Read how the vegetable oil you use is extracted from the bean. What they don't get goes into your textured soy protein and animal feed.

Other sources of oil that the Shaman came up with were looking for vegetable oil that passed its expiration date, and also trying to find an oil processing plant somewhere around here and trying to get the tails of the batches that they can't sell for food.

So, friends, keep your noses to the ground for sources of oil. Also, Oily SOB, it might be time to contact your big batch waste producers and to try and tap into the big streams of waste oil. The amount of effort we go to to collect small batches probably will end up costing more than just heading out to buy regular diesel. While it is still nice to run biodiesel in terms of being carbon neutral, helping farmers, and sticking it to the terrorists and The Man, it sure would be nice to make it pay too!


Post a Comment

<< Home