Have you considered using the blade and safety cage assemblies from those little 'personal fans' I saw in a junk mail catalog a while back? Lacking that, I would think they would be easy to scratchbuild, simply scaling up the dimensions of a smaller scale cooling fan. If the blade assemblies are free to pinwheel and you feed air from below with a hair drier or something similar the effect should be interesting.
The one thing I see from your photo is that the prototype plant would fill my entire layout space - on land too flat to allow easy hidden staging. I think I'll confine my on-layout ethanol production to a small pot still hidden in a mountain cabin, run by a couple of coal miners as a side business.
Chuck (Modeling Central Japan in September, 1964)
So, one of the main industries in my new freelanced layout is an ethanol plant. So I found this very interesting picture of such. Notice the "in" yard with all the grain hoppers and the "out" yard with all the ethanol tankers. As you can see it is an impressive complex and rather easy to kitbash using very commercial kits. There is a very important structure key to any ethanol plant, and are the cooling towers to condensate the alcohol vapor after it has been boiled to extract the water (same ol' principle as making moonshine). I can't find anything that simulates this structures ( at the top of the picture). So I've decided to scratch build them. The problem are the cooling fans. So here is where I need your help. I was thinking of using EMD loco fans in G scale, but I can't find any of those ( unlike in HO). Do you know where can I find those parts? Do you think it will work?