Still there. Mostly liquid versions. I just loaded up inlaws' 200gal trailer tank with "proprietary" home brew bio for their trip home in "Smithsonian relic" VW Rabbit Diesel. Should power their transportation till Thanksgiving, at least. Their pot leaf-peace sign painted microbus serving storage shed duties since rear main spun decades ago. Main saddle stretch a common malady of the design, imo. Offered to help repower with Corvair but too "AmeriKan" for them. Go figure. Lol They're excited about ev conversion for their microbus. Still sorting design for my F350 ev conversion. Lol
As contended by supporters of rebellion against Whiskey Tax, 1791-1794, "liquid grain" proves convenient on multiple levels. Hauling many tons of grain to distant market via draft beast wagon, before rail, proved MUCH practical to concentrate that value into liquid form. Lol
Solid fuels only really work out on large scale, imo. Where rail, river, etc can most readily transport solids in bulk. Hard to grow, harvest and deliver competitively against scale of WY coal. For example. Rail traffic in/out of THAT coal field truly eye opening. Imo. Just visualizing cubic feet of gasious emission each coal car represents... worth pondering, imo..
At least the O2 burned with bio combustion got released (last year?) with grain growth. Reuniting O2 released before fossilization has proven a life long worry, for me.
Displacing food growth for fuel growth another worry. The wife and I anticipate answering to our Creator some day. Lol. That said, grass etc consume minerals from soil. Minerals that might not get back into the system if burned directly. "Liquid grain" at least mostly burns starches. Minerals find home as mash mulch for garden, etc. Out of that "liquification" process. Lol.