Gasifiers...
 

I've recently become very interested in modding my '95 F-150 to become more fuel efficient and environmentally friendly. I am trying to see if I can design a wood-gasifier to run it on wood.

Some Background info (skip if you don't like novels :) ):

Naturally, the best way to do that is to shy away from fossil fuels completely, and use a free, carbon-neutral energy source. And I just so happen to have an effectively unlimited supply of naturally-deceased trees for free. I say naturally-deceased because I don't see any reason I would ever need to cut down a live tree (not that I would), because lightning alone kills more trees every year than I could use (and to make sure any tree-lovers won't get the wrong impression).

In general (and perhaps absolutely?), any vehicle that can run on gasoline or diesel can run on woodgas with minimal modification (which usually involves a manually operated air/fuel mix box in lieu of a carburetor). Unfortunately, my truck is fuel-injected, which apparently makes things a little more complicated, but I'll worry about that later.

/background info

I've found a couple sites before, but they've either been horribly out-dated, impossible to navigate, or full of nutcases (trying to create cold fusion reactors from match-stick boxes, according to plans they bought online-- you know the type). This place appears to have people with just the right combination of intelligence and rationality. ;)

There are some serious hurdles to overcome, though. And I hope someone here might be able to offer some input or support. Has anyone here ever done this?

Some problems I'll need to solve are:

1. Fuel (wood block) size. This is the primary problem at the moment. It is cheap and easy to cut trees into 1-2' sections, then split (resulting in pieces like so: (http)://realneo.us/system/files/CordofWood.JPG. Unfortunately, gasifier plans I've found online (from the UN and US publications, mostly) are just as bureaucratic as you'd expect: they assume perfectly-shaped cubes of wood from .75" up to 2" (as if wood can be harvested naturally in such form), and make no mention of the effort and energy -- much less methodology -- of getting such perfectly formed fuel chunks out of trees. Since it would take an impractical investment in machinery and fossil fuel to get an otherwise carbon-neutral and free fuel into chuck form, the design must be modified. I want to use hand-split wood of typical length. And, quite frankly, I'm not sure that would be practical either. But, if I can modify the design to allow for that, the only investment would be in chainsaw fuel. A gallon can cut down a couple trees, and 1 cubic yard (of wood) is the equiv of 5 gals of gas. So, that would make my truck go from ~19 mpg to ~500-1000 mpg (fossil fuel/wallet/environmental impact, anyway). There must be a way...

2. general safety issues. Issues include keeping heat away from anything it could hurt, keeping explosive hydrogen and carbon monoxide gases from exploding, keeping poisonous gases safe. There may be more I can't think of atm.

3. Fuel composition. I want to break down as much of the more complex hydrocarbons as possible to reduce harmful tars and other chemicals (and to increase efficiency). I want it to be very clean-burning.

4. Modifying the gasifier to match the fuel consumption requirements of my engine.

5. Getting the gasifier to work with my fuel injection system.

6. There probably is something I've forgotten :p

I probably have (or have access to) any kind of tool needed for anything that could come up, and I also probably have many of the parts necessary (scrap metal, mostly). The gasifier is basically sitting there, waiting to be designed and built. :) I currently spend about $250 per month in gasoline, so cutting that down to more like $5 per month would be veddy veddy nice!

Any thoughts/input/suggestions? Do you think this would be practical, or should I not even bother?

PS: Should I try my hand at building a small wood-gasifier first? I have a gasoline electric generator (to power a home) for which I could design one first. What do you think?

Thanks in advance! :)

bookmarked ;)

I've spent some time lurking on the gek site as well. There are a number of things I'm keeping in mind from those type projects (mostly the types of small tech problems I must solve on the way).

I'm sure there is a lot of useful info there that I could use. Thanks for linking it.

You've reminded me of one of my intentions behind this project that I'd like to share. I would very much like to do this project (whichever one... or both) while keeping as close to the following as possible: Using materials that I already have (from tools, to scrap, to fuel), build a fuel source for an engine/vehicle that I already have. I say this because anything I buy or commission is, by its very nature, using energy (i.e. is wasteful) to produce. I'm trying to impact the environment (and, secondly, my wallet) as little as possible.

Trash is plentiful, but creating a demand for it defeats a major purpose of my project (though I can certainly gain knowledge from such designs). Paper comes from trees... which are generally live before being felled (harvested) for their wood and paper. And the last thing I want is to have some incentive to buy more paper products. Plastics are mostly (all?) from already-sunk (fossil) carbon deposits that have been resurrected to poison the environment. The story is similar with other trash items. While it would be cost-effective, it adds to general poisoning of the environment (more harm than good). Using plastics (for example) in such a manner masquerades itself as a solution to the problem of plastics, where it really is nothing of the sort. In fact, it would decrease negative perceptions of such things, thus increasing their impact further. Don't get me wrong, those solutions would be better than using gasoline as I currently am, but I would rather try to find a carbon-neutral, and environmentally friendly solution.

Sorry I do not have much to add to this but I do not know how well this will work if you are going short distances as you have warm it up to go. To aid in the starting and heating of the gasifier check in to Free Heat! Its Everywhere! also ethanol soaked corks would work for great starters.

Germany used coal gas generators in their Kubel-wagens at the end of the war. When my father finished his 30 missions on 6-6-44, he ferried planes to Paris at Le Bourget. There were acres of parked Kubel-wagens sitting near the airport. All of them had coal gas generators, but they were also all booby trapped.

The problem that I read about is the tar residue from generating gas from coal, and probably even more so from wood.

Maybe a separator and a pressurized tank of fuel would be the solution, just a guess.
I know you can smell the turpentine from a rotten trunk of a dead tree. It is much more flammable than the wood itself.

As far as working with your existing FI system, the easiest way would be to have a pressurized tank of your alternate fuel and feed it into the intake manifold. The system should reduce the amount of your original fuel that is delivered to the engine.

regards
Mech

Check out Beaver Energy.

They have a wood gas Mercury Cougar... er Beaver.

Here's a video bite from the Mother Earth Fair from a couple weekends ago.

http://www.youtube.com/watch?v=LbbFwQ7RIMk

The microphone on Chip is mine. It was still on him from me recording his seminar on the car. I still need to get that video up to YouTube! :rolleyes:

http://gallery.me.com/benhdvideoguy/...12862137040001

http://gallery.me.com/benhdvideoguy/...12862139060001

http://gallery.me.com/benhdvideoguy/...12862140750001

The best part of the car is that it's actually a hybrid. It can still run on gas if you want. Just put the fuel injector fuse back in!

I've thought a little about wood gasifiers and it's my understanding that they work far better with constant loads than something like a car that has continuously variable demand. The reason is your fuel output is relatively constant while your demand for fuel varies by whether you're idling, going down hill, or climbing the continental divide.

That's why I think the best application would be in a electrical generator that charges a bank of batteries that operates an electric car or truck. Kinda like how modern diesel trains run now, except with batteries instead of varying the generator speed. Obviously this would be a major build from the ground up, but I think it would be the best use of the technology for transportation.

thanks for the input :)

@ Phantom. Yeah, that has actually been one of the major draw backs for me. But with where I'm living now, and my job, I have to drive a while to get anywhere. Most everything is about 1 hour away now (including work). I rarely drive to anything closer than 30 mins. So now, finally, it is becoming worth it to have a gasifier :) And regarding the starters, I have a few ideas like that. I think I'll probably end up keeping a propane tank with a torch (small flame-thrower) attachment that are normally used for starting camp fires. It would be quick, and would probably last for a few dozen starts between fill-ups (from the main propane tank). It would just be a matter of walking 20 ft., filling up the tank, then putting it back in my truck. But there are other solutions I'm considering as well. But that bridge is quite a way away, though. :p

@ Old Mechanic. Fascinating story. I first found out about gasifiers from researching WWII. I just had to find out what those contraptions where on the backs of those vehicles! lol

From what I've read, storing wood gas is dangerous (the gases separate, which could cause major problems). So all gas produced would have to be used within seconds. (It is worth noting, however, that I'm researching means to separate the gases and store them for future use, in extra commercial gas tanks. But that's another project. ;) ). Tars are a major concern of mine. They all break down eventually if heated up enough, for long enough periods of time, so I plan to modify designs to take that into account. I can sacrifice a little efficiency for cleaner fuel. Perhaps I will modify the burning chamber to get hotter for longer, and/or modify or add a fuel cleaner in the line. Many substitute filtering mechanisms (wet saw dust, for example) with cyclones... but I just don't trust cyclones (though I might have both :) ). After all, it is a full-size truck, not a hatchback. I have a some room to work with ;)

As far as the FI goes... I haven't researched that much yet. I may have to add a turbo or something to compress the gas just before it enters. But I really don't know yet. I really do need to start researching that, though, as it could easily make or break the whole project.

@ bennelson. I'm dling the vid now, and I'll check it out later. It look promising. I would very much like to keep my truck as close to pumpgas-ready as possible. F-150's (of my gen) have 2 fuel tanks (and thus, fuel systems), and I might be able to modify it to where I can go back to gas with very little work. I'd love to use the existing fuel system swap switch (which turns on/off fuel pumps, and swaps input) and just add another switch or two that turn on/off the gasifier inputs or any related devices. But I need to do more research on gasifiers with FI to know if that's even possible, though.

@ endurance. Unfortunately, you are absolutely right that I will have to find some way of keeping the demand for fuel as close to supply as possible. This goes for everything from design of the gasifier to match the needs of my engine, down to driving style. As a matter of fact, you are ever more right than you realize. If demand falls, supply falls, and fuel can become dirty, and lots of other issues. That is because it is actually the engine "sucking" gases through the system that keeps it going (and hot enough to break down the tars and whatnot into clean, combustible fuels). Batteries are expensive, heavy, and would require some extreme mods, so atm I'm not seriously pursuing that route.

The idea I'm toying with right now is keeping fuel demand constant using a blower, regardless of actual engine demand. The plan involves a blower controlled by a potentiometer (which is attached to a fuel pipe and has a spring and a plunger that adjusts the potentiometer based on pressure in the pipe). So, when pressure is too high (actual engine demand from engine is low) the blower speed is increased, to keep the demand from the gasifier more-or-less constant). The unused gas with be vented to a tube in a safe place that has a valve with a spring (self-adjusting). It will probably be burned off somehow. Yeah, it is wasteful, but I won't have to keep my engine at a zillion RPM just to keep the fuel flowing, and I can just drive (more) normally. I need a blower in the system anyway, so it isn't much of a stretch to modify it to work with this function as well (in theory, anyway). Of course, I'm absolutely open to ideas on this and everything else, though. :)

again, thanks for the input people :)

The more I think about it, the more I think I should build a smaller one for a standalone electric generator first :p (but the I keep thinking... time is money, and another month is another $250-$300 I could have saved... ugh lol)

On a fuel-injected vehicle, all you would need to do is add a switch that turns the fuel injectors on and off.

You would pipe the synthesis gas into the air intake of the engine.
Simply turning the fuel injectors on or off would allow you to run the vehicle on either the wood gas OR gasoline.

Also, a number of alternative fuels are good at running a car, but not STARTING it. (For example, ethanol systems in cold climates.)

The hybrid system would make it easy to start the vehicle on gasoline, but run it on wood gas.

Hmmm, it seems like a great cruising/constant load fuel and your blower idea seems to be in the right direction. I wonder if you could create a hybrid system that uses some gasoline when you need power for acceleration, but once at speed you'd utilize exclusively wood gas? Seems that would get around the need for more fuel when you were accelerating, but still benefit with constant load.

Edit: great minds think alike (or fools seldom differ). I was writing this at the same time as bennelson.

Gasman what state do you live in.

When you get some good links on building them post it up and hopefully we can add a how-to to the wiki.

Since I'm not sure how one actually works I'm going to suggest it any way when you have the extra gas that you are not using it could probably be piped back the the air intake on the gasifier. Also look in to the rocket stove for the burn chamber.

Almost forgot if you disable the EGR and use its location for pumping the gas in it should equally mix with incoming air. I assume the truck has a separate unit for the EGR.

I researched EGR a bit, and I just might be able to use that as part of my fuel system. If possible, it would have the added benefit of not having to drastically alter (as much) under the hood. My first choice would be just to reroute the exhaust back to the exhaust pipes to keep my computer from freaking. (... and to take care of those pesky CO fumes! :p ) That idea has officially made my list for considerations for where to pipe in my syngas.

The idea of piping the excess syngas into the burn chamber seems to have merit, that's for sure. I'll definitely play with that idea some over the weekend. :) It might actually be used in that way to raise burn temps (thus further breakdown of tars), and may yield a higher concentration of combustible gases relative to inerts (like CO2), or at least an increase in effective fuel yield (per volume of dry fuel). If that works, and it wouldn't require a significantly more elaborate air/fuel mix box (or equiv device), then it could very well be a better option than just burning it off. :)

Regarding the hybrid-type designs... I'll see what I can do. From what I've been able to find so far, it probably won't be practical to design a system that can be switched over rapidly (on the move). It would be more of a backup system. I doubt I'll get to switch it over in less than a couple minutes. That being said, if at all possible, I want to make one where I could switch it all over in less than 10 minutes.

Before undertaking the actual build, I want to be confident that: 1. First and foremost, if the design I end up with doesn't work (or eventually fails, I want to be able to restore my vehicle to the way it was before within a day or two. 2. that I've thought through each part of the system enough that I'm confident there won't be any major hangs when I do build. And 3. ... that the system will actually work. :p

I still have lots of research to do, though. And, thanks to you guys, my list just keeps getting longer, lol.

an update... (I'm going to keep detail here, for those who are curious, and for those who may be interested in similar projects).

(forgot to add earlier that I'm in middle TN)

Well, I decided I wanted to do fuel testing this weekend, instead of working out modified designs to accept my preferred fuel (regular split wood). Since most designs that I like have to do with more-or-less standardized blocks of fuel, that is what I created. I actually thought a bit more about trash, and worked with it. I used only paper products for these tests, which I separated into two categories -- newspaper, and printing paper/envelopes (mostly junk mail).

I used the newspaper for proof-of-concept tests that are made to prove the idea, and not feasibility. Any efforts in batch manufacturing are wasted if the final product wouldn't work anyway. ;). I wanted to see if 1. it was possible to make such blocks with only paper and water, 2. if such blocks would have acceptable burn qualities, and 3. how much work it would take to make such chunks.

I initially took two full sheets of newspaper, cut them up, added a lot of water, and blended them in a blender into mush (which only took about 2 seconds at full pulse). I drained the water, then painstakingly compressed the mush in an empty soda can to shape it and get out any excess water. Then, I made a very basic kiln and dried the block. After the block cooled, I lit it and it performed much better than I had even hoped for. :)

So, concept proven. Next I used shredded paper from junk mail and just added water (leaving it in strips, not turning it into mush). Instead of painstakingly compressing it into a soda can, I cut a 6" long piece out of a 2" diameter 1/8" thick mild steel cylinder (pipe). (Note: I tried 1/16 pipe first, and it quickly failed. I would need something thicker than 1/8" if I wanted to make many of then). Then I filled the pipe with the paper mixture, and used a 12 ton hydraulic jack in a press to compress the mixture from 6" down to 1.5", removing most of the water as well. I made about 4 blocks before the pipe split, then I flipped it and made a few more with less force. Though it was faster than making them by hand, it was still impractical. I have not yet tried to ignite them, because they are not dry enough. If they work well, I'll try again without water-- just using the press to make chunks from dry paper.

Unfortunately, atm all signs are pointing to fuel block making being impractical. So I'll probably have to choose between 1. using loose fuel of some sort (some sort of trash), 2. sawing wood into smaller chunks, or 3. redesigning the burn chamber (and perhaps some other sections) to accommodate standard split wood. I will keep with the final testing of the fuel block concept, though.

Note: DO NOT use a microwave to test moisture content! I had a specimen ignite while doing this (at only 30% power, after about ~1 min)... if I wasn't right there to carry it away, it could have been a very bad situation. Embarrassing, yes, but I felt I should share for safety's sake. :p

I do not know if it would work with size constraints but on instructables a guy took news papers soaked them in a 5gal bucket for 1-2days. Then he removed them and pounded the sheets of paper with a rubber mallet on the ground to break the fibers and make it easier for them to stick. After doing that to both sides he used a dowel rod to roll the paper in to logs let it dry and then started fires with it. You could do the same and when dry cut the paper logs to size.

You are planning to split enough wood to run your truck on?

You are looking for efficiency, yet you live an hour from everywhere and drive an F150?

Moving and/or buying a different vehicle might make a lot more sense. What are you carrying with you that makes you need an F150?

Is splitting wood the most profitable thing that you can be doing with your time? How many dollars worth of fuel will you replace if you spend an hour splitting wood? Have you done a cost/benefit analysis to determine if this is the best use of your time?

Thanks for posting this cool woodburning car. I think the creation of wood gas lends itself to running a stationary generator rather than a car or truck. Mainly due to the weight and size of the burning materials and burning equipment. Alot of heat is wasted in the wood burning process, if that could be reused somehow the EFF would increase.

Phantom: I put some paper in a bucket after reading your post, but I haven't been able to get around to it so far. I'll let you know how it goes. :)

hypermiler01: My preference is to use split wood, but I'm not done with testing other possible fuel sources yet. I might make it accept a more diverse array of fuels. And when you say "enough," it seems to imply that it would take a lot of wood. I could split all the wood I would need for a month in a few hours, so time and effort (for splitting wood) is not an issue. Plus, it is good exercise, and I'd be killing multiple birds with one stone (safely removing dead trees, so they don't fall and injure/damage animals, people, or other trees). So money saved (money earned) is not the only benefit, and I would be doing almost all of the work anyway. Looking at it strictly monetarily, I would "earn" about $300 for a few hours' extra work one saturday/sunday a month, once built.

I am seeking several types of efficiencies. Monetarily, the money can be used better elsewhere, especially since I have an unlimited fuel source (fuel resource efficiency) that I haven't exploited at all. Environmentally, I wouldn't be using sunk carbon, or paying others to damage the environment to find more fossil fuels. The materials and tools are already in my possession as well, so it would be mostly time and research that I'd invest. Kaizen is another major reason. I could go on, but any of those would be reason enough to do it on its own... assuming it is feasible, which I have yet to determine. But, to more directly answer your question about my use of time, I do not run my personal life like a business (planned, optimized actions, and so forth). They are two very different things, and strategies for success in both differ greatly (in fact, they are almost opposite n many ways). So long as my actions are productive, and myself and those around me enjoy them and benefit from them, that's what I do.

And yeah, I could just get a little people carrier for a daily driver. I don't really carry anything very often, which is one main reason why I'm considering my alternatives-- buy a fuel-efficient car, or modify mine to use less pump gas. I haven't ruled out getting a little people carrier, though. But first I'm looking into the gasifier. If I find a way to make it feasible, it would be better for the environment (planet) and my wallet (among other things) than just buying a more fuel-efficient car. Since the truck has an open bed, I wouldn't need to make many modifications to the truck itself. The truck also happens to have a few other advantages that make adding a gasifier easier than normal.

MorphDaCivic: The main reason gasifiers are suited best for stationary generators is that they perform best within a narrow fuel demand range. Since the fuel demand in a vehicle engine (when driving) often varies by more than 1000%, something has to give. What most people do is design the gasifier for a certain demand, then keep the engine's RPM within a given percent of that demand (running around in high RPM all the time). My solution is to keep demand constant by using a blower that adjusts itself to supplement demand when actual engine demand is low (so I don't have to change my on-road driving style much, if at all). That way, if engine demand is low, the gasifier is still operating optimally internally (though the fuel is going to waste). Since I have effectively unlimited fuel, this is not an issue for me. :)

I haven't had time to brainstorm any design modifications for the burn chamber, unfortunately. When I have time and get some ideas, I'll update. :) Hopefully I'll have time this week.

As someone who just spent a weekend doing some wildland fire mitigation using a six inch chipper, I'd say that's probably the best wood gas fuel source. Easy to shovel into a small opening, fuel dense, and easily available on the cheap. My neighbor uses a burn barrel to get rid of yard scraps and says wood chips just will not burn, but whole branches burn just fine. Given that what you want is anaerobic off gassing, that seems like the perfect wood gas fuel. As for the fuel to heat the chips, probably split would would work better since wood chips don't burn well because they can't get enough oxygen to them due to the density of the fuel.

Now that's a zero waste solution.