I love sunflowers. The incredible amount of sheer LIFE that they put forth in a season is awe inspiring. Watch a Mongolian Giant grow in less than 4 months to the same 14′ height it takes 70-80 months for even a fast tree and you get a feel for what I mean. Plus they are gorgeous, attract lots of benifical bugs and feed the birds in their critical late season fuel up for their migrations.
But I have a wicked strong practical streak (in case you haven’t noticed) so I look for other things ways that plants can help out on the farm. And Sunflowers function stack in spades! Whether it is turning Sunchokes into Ethanol, or growing annual Sunflowers for their oily seeds you can fuel your farm with them! With my latest craze being a diesel mini-tractor I have veggie oil (straight vegetable oil i.e. SVO) and bio diesel on the brain. In the last several posts I said I could grow sunflowers to fuel the tractor. That is not entirely true. Well, actually it is, but it isn’t nearly as easy I had thought. I spent several hours today reading much of Journey to Forever’s freaky informative pages on SVO, Biodiesel, and everything in between. When I need to answer a sustainability question I either go to ATTRA of JTF and they have almost never failed to steer me right.
There is a strong mis-perception out there, that I had subscribed too, that you can take vegetable oil and run your diesel on it. And you can, but it needs to be really warm out and you must have an engine built for it (like the original diesels). Today’s engines are designed to run on refined low sulfur diesel, which has a much lower viscosity and better burn than SVO, but also makes them perfectly compliant for biodiesel. You can modify a diesel to run on SVO, but it takes alot of stuff like secondary fuel tanks, built in fuel heaters, modified injectors, etc and it won’t really work on an air cooled walk behind tractor.
So I can’t just take sunflowers and squeeze the seeds into the tank without killing my un-killable tractor. I have known that making biodiesel is, well, if not easy then certainly not hard… especially given the fact that my eco peer group here in Jefferson County just built a machine to turn woodchips into hydrogen/methane gas to run a 65hp “Straight 6” (pics to come once we hook the engine up in April!). When you first read about making biodiesel it can seem really damn scary. Words like Methanol, Potasium Hydroxide, “causitc burns”, “poisonous fumes”, etc can turn you off real quick. But then you dig a little deeper and you learn that Methanol is basically Kingsford lighter fuel, Potasium Hydroxide is just lye and used as draincleaner and the same warnings are found in the same chemicals that many of us used to keep under our bathroom sinks. It isn’t that bad, it just needs a marketing department.
The chemistry is not that complicated, but the set up looks a bit involved I admit. However, I really like JTF’s 5 gallon mini batch set-up as it would make a 1-2 year supply, or enough to help fuel several of my friends TDI’s if I used it every month or so. It seems to be about the right size and within the relm of talent that I have surrounded myself with.
Back to the sunflowers. So how much can I expect to get? JFT’s sources claim 102 gallons of oil per acre. That is alot of oil from the sunflowers, and the left over mash makes good chicken/pig feed and you still have those 14′ stalks for mulch! I certainly have the available land to grow a .25 acre stand, and I would just need to fab up a home oil press. Again not too hard if you have access to a machine shop, a welder, or if no one else will help, the A-Team… if you can find them.
The final thing that had me concerned about all this is the glycern/methanol/lye stew that you are left with after you get your biodiesel. None of those sounds real, er, benign and I am certainly not going to take something as inert as a sunflower seed and turn it in to hazardous waste. But JFT has the answer to that too. You’re gonna love this… COMPOST! Once you skim off the biodiesel, which itself is biodegradable, you can then separate the by product back into its three parts: Methanol (to be reclaimed in a condenser for reuse), Free Fatty Acids (which you can mix with sawdust and burn to heat the next batch of biodiesel or you can compost it too) and Glycerin which makes a good all purpose degreaser, but can easily be composted and if you used Potassium Lye as a catalyst you now are adding potassium to your compost pile. Nice!
This was a nice 800 word way for me to say that making fuel for a tractor this size, or even significantly larger, on site is very doable-devoting 1 acre and a few hours a month can net you about 80 gallons of biodiesel, which is about 40 times more than I will probably need (if I am tilling up an extra acre), or put .25 acres under and get 20 gallons in about 4 batches. Nice, scaleable, and very user friendly.
I now call my Sunday Research Project to a close!