Compared to cutting trees, foliage and brush on forest ground is easy to collect (just “rake the forest”), and easier to shred into little pieces, ready for the auger, into gasifiers.
If you live in areas with high forest fire activity, such as California, how do you plan to collect “surface fuel” from forests, for running a truck?
Does foliage/brush gasify in a similar way with wood? How many miles per lb?
Look at how much foliage fuel in the ground! Do they gasify?
I use twigs and sticks to make charcoal for my gasifier.
Foliage and leaves are too light and fluffy to use. We measure “miles per pound” so you might need a semi truck full of leaves to go any distance. 
Good morning .
I think a very broad statement could be with enough effort any biomass could be gasified . The very easy gathering of the foliage fuel can be gasified but with a lot of effort . I put more effort into preparing the fuel to have less effort while using it driving .
With my dodge dakota trucks driving 50-70 mph I plan on getting about 125 miles per hundred pounds of dry wood .
You can find a lot of information in the ( wood supply ) tread .
Thanks Wayne
I was thinking the wood chip gasifer would be the best bet but I think I have only seen people use them on small engines like lawn mowers.
My thoughts are…
the more diverse any hopper of fuel is, the harder it is to make consistent gas, and to use that gas efficiently. if the gas quality is varying too much, adjusting for it becomes tedious. This is a new thought and experience for me since we acquired our maple fuel supply from the cabinet shop. I learned how to DOW on whatever I could find at the moment…old spruce cutoffs from construction, good hard wood fire wood, punky pine logs, sawmill slats, pallets, old furniture, whatever I could find. . Then I got a supply of consitently sized, typed, shaped wood…WOW! What a difference. I am now a HUGE advocate of spending your time with fuel prep.
I think the stuff you are talking bout can be a broad spectrum, mixed up material (correct me if I’m wrong), Assuming you’re tlking bout picking up downed limbs in the woods? re you including leaves, pine needles, etc.?
If so I think with these types of fuel and with smaller pieces of wood, you get more bark/wood ratio. Same with leaves, etc. Those things make more tar than clean wood. another thing to deal with. But like Wayne said, it can all be gasified, just have to decide how much work you want to put into it for how much benefit.
We use Don’s approach. The “junkier” material we have that we want to use for fuel, we put in the charcoal retort and use it in the char machines.
That goes for the punky pine, sawmill slabs, and all the stuff we used to try to use in the trucks… even odd-sized hard maple these days. The fines from that process end up in the garden.
But I know that not everyone has an option like that.
I just know that getting one, for us, was life changing when it came to DOW. Now we DOW almost every day. Before, it was kind of a chore we felt obligated to do sometimes. LOL. Funny story, Had a little spat with my wife the other day. We were going to get tested for COVID19. She wanted to take the mini van so I wouldn’t have to worry about driving while sick. I wanted to DOW. I told her “the wood storage is almost full, we have to make room for the next load” Hahaha. She finally won by citing the $1.29/ gallon gasoline prices and a well arranged emotional plea…I finally gave in and let her drive on gasoline. But the whole time I was feeling like I missed an opportunity. 
Hey Billy
Even with one dead cat in the hopper one has to make corrections on his gas /air mix
I believe modern cars have ECUs that can automatically adjust mix ratio based on O2 sensor, it might need to be tuned for wood gas.
Can we make the fuel more homogeneous, by shredding them to little pieces and blending them up? So any given volume of the fuel is a consistent mixture of wood, bark, leaves, soil, grass… and maybe trash that park visitors left behind.
Yes , we use the ecu as an hybrid feature .
Welcome to the DOW Cow Dog,
I believe you have fallen into the “free” “found” fuel trap.
Once you switch over to personal sweated-value-added wood fuel is when gasification for motor fuels becomes manageable.
And this will mean intentionally made wood fuel bits-chunks for their controllability, low ash and low tars.
Live and Learn man. We all have. The “free-fuelers” never endure through all of the gasification-for-work-use learning experiences. Flash-in-the-pans; then nothing more heard from them. They are off and gone to the next “free” seems-easy dangle.
Regards
Steve Unruh
Hmmm-----
No.
Now you are talking about something you might call “wood pellets”. I think there are a number of folks out there who do use wood pellets, but I will bet that they don’t want ANY bark or soil in the mix at all. Maybe someone else will tell you why.
IMNSHO, by the time you make the raw material into decent wood pellets, you will have lost most of the time and money that you might have saved through DOW/gasification in the first place. Besides, you will have breathed so hard and used enough electricity that you will add a bunch of CO2 to the atmosphere .
Thanks Steve.
Cost is always the top concern of consumers. COVID has broken the world economy, everyone must save the last penny to avoid the debt trap and eventual backruptcy.
Whole chunks of stem wood requires a higher cost of either manual processing or a heavy duty wood shredder.
Twigs, shrubs and foliage already have low cost shredders/chippers on the market.
I don’t think ANYBODY uses “shredded” anything successfully.
Others- please correct me if I am wrong, but “low cost” shredders/chippers make stuff that is 'way too small to be useful in gasification. Just throw a bunch of that stuff on a roaring fire and see what happens. Maybe okay material for making pellets, but then even more cost is added.
This is what you want to process limbs that have fallen, fast n cheap to build; JO´s Rebak Chunker
Pellet stoves can use shred/chips pretty OK. The burn rate is limited by how much fuel the auger pumps into burn basket, not by the surface area of fuel particles.
my main source of charcoal comes from forest cuttings from conifers. charred branches and tree heads are beneficial in many ways.
carbonization reduces the risk of forest fires in the summer. carbonization facilitates circulation in the forest and future silvicultural work. carbonization fixes part of the carbon for hundreds of years (possibly)
if the energy released by carbonization in the forest could be valued it would be the most efficient way to make coal for me
If the fuel don’t flow, you won’t go.
Thanks Mr. Pete for the quote . I like it !!
Just like sand through the hour glass 
CowDog I’ll refer you back to my own personal experinces as a once 17 acre tree-lot owner.
Back in my early 2007-08 wood-for-motor-fuel seeking I gathered up from the forest floors buckets of just Douglas Fir bark chunks; buckets of just DF cones; buckets of firewood making produced splinters and irregular sized chip/chunks; and even buckets of chainsawn dust-chips.
The bark chunks gasified very poorly with much tars produced and too high of flows clogging mineral ash.
The fir cones initially gasified; then too dense light would always not settle compact and make void hollows.
The varied lengths wood splinters would always crossways bridge hang up.
The chainsawn eject chips were the worst for gasses exchanging flow clogging.
ONLY the carefully hand sorted out large wood chunks worked.
So really man. Referring back to your dryland pine forest floor picture . . . . take the actual limbs and tops and de-twig then and run them through a Rebak style chunk maker.
Gasify that, and you’ll begood-to-go with any simple manual operated gasifer system.
Then no auger drives with drive motors and power supplies - - most all of this China sourced - - trapping you into one-world-connectiveness dependencies.
Leave all of the rest of the found duff right there on the forest floor as ground cover soil making stocks. You want more trees? Don’t human greedily rob the soils. Never take more than one third.
You ONLY succeed at personal use gasification for moter fuel by intense focusing on just THAT as your outcome goal.
Forest wild fire cleaning? Not your goal. A distraction. Let the Gov’Mints pay for that. Ma’ Nature WILL rebalance this with wildfires.
Save the world overall CO2 redudcing? Not an affordable goal to get your engines up running and useable. A distraction.
Keeping the Distrations pictures other will force onto you minimized. Failures driving. Heart breaking. Hands off automation is a distraction. Period.
By the way I have since learned needing in-house space heating 250 of 365 days of the year just how to use all of these poor forest and fire wood making fractions in a medium/large bulk burring in room wood stove. Discribed recently on two of my posts.
Sigh. O.K. for heating but not the best use for these considerd “waste” fractions.
These really should belong back to Mother Nature for forests soil making. Or at least used for chicken yards and pathways mud cover. Then once mudded and chicken shit enriched mixed moved out to the garden plot. for foods growing.
Regards
Steve Unruh
Yes, this is true. The “cost” benefit of DOW comes only over time. Developing the system and lifestyle that makes DOW a central part of transportation. Hobby DOW will inevitably cost too much to be “cost effective”. While being able to consistently use the technology to “not buy gasoline” . It means having a system of fuel (wood) procurement, processing, cutting, drying, storage, that actually allows you to put tens of thousands of miles behind you on wood. Miles that you would have driven anyway on gasoline or other bought fuel. If that is not the equation, then “cost savings” is not really a part of it.
To be sure, there are many other reasons to get into DOW. Fun, exclusivity, “self/local” reliance for resources, it’s just cool, hobby, etc…but the only way it becomes cost effective is if you replace a significant expense with it, or use it to make lots more money (which means replacing a business expense with it) heat source, transport, hauling, brick kiln, food preservation heat, etc…)
If you’re talking about replacing gasoline for normal driving/transportation, the math is pretty simple. How many miles does one normally travel, how many gallons of gas does that take, how much does it cost per gallon, …do the math and figure out how many miles on gasoline you have to replace with wood (or other) to replace x number of dollars worth of fuel.
Keep in mind that you will still need some gasoline to meaningfully use DOW regularly for regular driving. (probably) I don’t know anyone who drives DOW as an everyday thing (Wayne told me he only knows of 10-15 in the USA doing it) who does not use some gasoline.
Once you know (guess) how much you will actually save per mile/year/etc. you can look at what established systems cost people who are actually doing it.
Add up the cost (if not already available) of gathering the wood (debris/fuel source), building or buying the machine to cut it into pieces you like, the electricity or fuel to operate it, the building (floor space, blowers, kilns, grinders, etc.) needed to dry it appropriately, the bags, buckets, boxes needed to store it, the shed, silo, tarps, old junk cars needed to stack it in. And obviously the mechanism you need to convert it into DOW-able gas. Don’t forget the rebuilding of the hopper or the tank or the replacement of the blowers etc. after a year or two or three of continuous use.
Some of that info only comes from people who have done it…
Then take your two numbers and compare them and you’ll find out how many years it would take to actually pay for DOW from a “cost-efficient” view.
You will find that it takes a very unique lifestyle and set of circumstances to actually make it cost effective. Our family has driven almost 60,000 miles in the past 14 months on wood in 4 different wood powered vehicles. That has saved us some money at the pumps, but when you consider the cost… We have basically broken even with the cost, not including time, and not including a totaled truck, or purchase price of vehicles.
Now, that was all just considering the systems and processes that have been developed already by other people over the course of decades of investment and invention. Well established tech and process like the WK etc., using established parameters on everything from gasifier design, to wood size and engine modification, etc.
You asked the question if a new (less studied) kind of fuel could be used. The short, unqualified answer is “yes”. The practical answer is, “Not for many years.” If you want to be the guy who sets his heart on developing a “new” fuel supply for the “industry” we are all going to be very grateful to you and appreciative of your efforts. But do not be deceived, inventing new technology and proving it always costs more than it produces…at least in the short term. I imagine Wayne has much more money invested in the WK over the decades than he will ever get out of it by driving past the gas pumps. He has gotten a lot of other benefit from the investment. And I would argue that he has made the world a better place for his efforts. But it was not “cost effective”.
I would also suggest that if a person wants to develop “new” tech, first he needs to learn the established stuff. Maybe not everyone has to do that, but I find it much more effective. I make the analogy of musicians. People who start new genres of music all start off learning the classics and then modifying and expanding them. Same is true for most things I think, including the invention of new gasification tech and process.
Please do not misunderstand me. I am in no way trying to discourage you from developing some new way to do stuff, or saying that you can not do it. I actually hope that people do develop things, like the people on this forum who spend their time, effort, money and generously share it with the world. Great stuff. Totally worth getting involved with. It’s a very worthy cause for people who are into it.
But like Steve U said, people that think there is something here (in gasification) for free don’t last long. It is my personal opinion and experience that many of the rewards of DOW are not in the form of $ saved by using alternative fuel. And also, for the cost savings that you will see, it requires a shift in lifestyle over a long period of time.
If you want to use alternative-alternative fuels. My advice is that you set aside any thoughts of cost savings, do a cost/benefit analysis, and decide if you want to invest yourself in learning the alternative first, then from that experience (which will be costly in time, money, commitment and effort) you can develop something new.
That said, what ever you chose to do, everyone here on DOW will hep you all we can.
Apart from cost effectiveness, there are a long list of reasons why one should DOW. In fact, there are entire threads on this forum dedicated to the subject.
The cost/benefit comparison equations I haphazardly threw out above can also change. For example, If we enter some new era (as you mention the destruction caused by COVID19), it is conceivable that the cost of gasoline for instance could go very high, or it could be unavailable at all. I imagine that in such a situation, those few of use who can DOW would be able to make a very good living just driving people and goods from place to place, etc.
My point…there are a lot of other reasons to DOW than cost effectiveness. What I wrote above is only aimed at giving you a realistic view of the money side of the idea, not meant to discourage you from the pursuit.
Sorry to be so long winded.