So, after a lot of brainstorming, I think I've hung my hat on an overall scheme. I'd like your thoughts, I may have overlooked some issues or potential headaches.
I am going to go with charcoal. It will be carbonized wood/straw pellets.
I am going charcoal because I drive short distances most of the time, I drive in freezing weather 1/3rd+ of the year. My vehicle use is on short notice a lot of times. Visible smoke and equipment on the vehicle are not desired, and lots of driving in town will be done. Wood/straw fuel maximizes my access to feedstock. I have inconsistent availability of wood, but straw is almost free for the taking. Pelletization and making same into char ensure a reliable stream of fuel feedstock all the time.
I am expecting:
a. a fast light up
b. Easy fuel storage with no spoiling, water absorption or rotting.
c. Less soot in the intake tract.
d. No fundamental need for gas cooling
e. Simple gasifier and system construction
f. Less real estate on the vehicle required
g. Less weight on the vehicle
h. Clean tar free gas 99% of the time.
I. At least 1.5 miles per lb in a 5000-6000 lb vehicle with water drip
J. No wood smoke smell on me all the time
k. No vinegar / tar to drain off and dispose of.
The manufacturing of the fuel to be discussed later.
The vehicle will be the highest power to weight 4 passenger OBDI vehicle I can get, likely a big block quad cab truck or Suburban. Still weighing options.
It will also be turbocharged eventually, as I don't see an as-is OEM option that will get me to the speeds I need to do on occasion. This can happen later after everything is up and running. I understand a seal on the compressor side back plate will be required to keep oil out of the compressor housing under the high vacuum conditions of pulling on the gasifier. I also understand that the turbo sizing should follow the requirements of an engine that is half the size of the one in use for wood-gas.
The gasification system will consist of a divorced hopper that auger feeds a sizeable reactor employing many Don Mannes innovations, and some of my own ideas. Hopper will be huge and carry enough fuel for 3000+ km (based on 18 lbs cf charcoal and 2 mpp).
No significant gas cooling will be employed other than aluminum piping feeding the gas to the front of the vehicle via the underside.
Water drip will be employed, I'll be using a true wide band A/F monitor, some details I'm unsure of eg. should I pull gas thru the hopper to eliminate the air, or should I use a rotary airlock at reactor input?
Let me know what you think. I've got a ways to go before I start building the vehicle as I want to figure out a long term sustainable fuel manufacturing plan before I throw money at a char powered vehicle. Charcoal production seems to be the only real drawback of charcoal overall.