John Wolfram wrote:
Wyatt Brush wrote:55 Gallon Drums are not free around here. If you can find them for sale, they are between $15 and $25 each. You can sometimes find plastic ones for $10, but that won't work very well for roofing a shed.
That's about what they go for around me too. Any free metal is generally scooped up by the scrappers pretty quickly. Based on the dimensions of a 55 gallon drum, when flattened you end up with about 16.5 square feet of roofing, or 90 cents a square foot based on a $15 drum. My local big box home improvement store is selling 12 foot by 3 foot panels of metal roofing for $22.03. That works out to 61 cents a square foot for something that is ready to go.
Dillon Nichols wrote:Wyatt, your link isn't working as posted for me, but it seems like maybe this is where you meant it to point? http://www.agmrc.org/commodities-products/grains-oilseeds/pennycress/
The link states 800lbs per acre as a reasonable conventional farm production yield, with aerial seeding, chemical fertilizers, and combine harvesting. With 'up to' 36% oil content, this would translate to a theoretical max of 288lbs per acre from your 800lbs of seed. Assuming it weighs about the same as canola oil, this is about 36.5 gallons of oil. I'm not sure how efficient the biodiesel process would be with this oil, so I don't know how much biodiesel that ~36.5 gallons would translate into.
The big question in my mind is how could one harvest enough of these tiny seeds to get a meaningful yield, without involving a combine!
Interesting document containing oil/acre stats for quite a few crops here: http://www.attra.org/attra-pub/biodiesel_sustainable.html
36.5 gallons/acre is on the low end of the crops discussed. That doesn't mean there isn't some niche where this would be a good fit. Soybeans, which produce most of the virgin biodiesel feedstock, are only a bit higher yielding in terms of oil... but the oil is essentially byproduct of the more valuable, and subsidized, livestock fodder.
I don't know. I harvested some wild grown Pennycress by hand, this summer, but it took forever. I wanted to try to extract some oil, but because of all the time that went into harvesting the seeds, I decided to save them for use as a spice instead. If I had machinery like this: http://www.eqmachinery.com/index/products I could have enough seed, to try out extracting the oil. You can get a hand cranked oil press: https://www.lehmans.com/p-4290-hand-cranked-oil-press.aspx, but I was just going to try grinding the seeds, then boiling the flour in water, and skimming the oil off the top. I heard that that is how the American "Indians" processed the oil out of sunflower seeds.
hunter holman wrote:what do you use to press it out? and how much do you have to grow to get a litre?