Hi, I’ve been lurking for a few weeks, just bought the book the other day…
Had hoped to meet everyone in the Friday hangout, but apparently we had plans with friends, so I missed this week…
I’m new to gasifiers obviously, plan to build one for a generator, around 7-10k… Been doing a lot of reading, but still pretty much lost lol… Hope the book helps in that regard… Anyway, thought I’d finally drop in and say hi
HI, Matthew,
Nice and helpful bunch of folks on this forum! I have only been here for a year, and haven’t built much, but I have been reading posts, asking questions, and learning how this wood-gas thing works!
Welcome! 
I second what mike renaolds said, lots of mostly good help here at the dow, most the info needed is in the book, though i have too admit , i made a big note book of questains before i read the book. Enjoy your projects, the wk book gasifier is best suited for 4 cyl or bigger engines, though there is lots of help on smaller engine gasifier builds.!!! Welcom too the DOW .
Welcome along Matthew , now let the fun begin
HI Matt, Welcome to our wood gas family, don’t be afraid to ask any question, we have all been there.
Good morning Matt and welcome to the DOW 
Hi Matt welcome, to the best Gasification site ever, the people on here are the most experienced people you will ever meet all in one place from all over the world. They represent hundreds of years of experience when you add it all up. Listen to what they say, they are here to help you have a successful working gasifier.
Bob
Welcome Matt. For the engine size you are talking about pay attention to the Charcoal discussions in the “Form”. TomC
I’ve seen lots of discussion about properly sizing for the engine you want to run… Obviously you can’t run a F350 off of a soup can sized gasifier, but why can’t you go bigger than necessary? Is it just a matter of wasting fuel?
My original plan was to use freely available 55 gallon drums, but reading here it sounds like they’ll be very hard to weld on, and will fail quickly due to their thickness
Hi Matt,
If we’re talking wood gasifiers on vehicles I think it’s mainly about heat.
The gasifier has to be small enough to handle idle and still stay hot enough to make good gas.
If you are talking about charcoal gas, the same gasifier can power anithing from a 50ccm engine to a car. It gets tricky with wood. You want it sized perfectly for the engine for optimal performance (no tar, no ash in the gasifier hearth). l am talking about hearth dimensions, there are strict rules on that. The other dimensions (wood hopper, ashpit) can be changed as needed.
Ahh, where can I find info on sizing?
Hi Matthew,
I thought I’d share my experience as part of the small engine gasification quest. The chart Matt is referring to is the one I also used for sizing my stationary unit. Since I originally planned for 25- 30 HP, I used line C of the imbert dimensions. Some of my dims.(firetube) are not quite exact, but close enough that I produced very good gas (imho). You need approx 2 cubic meters of gas per horsepower per hour, so at 30 HP I would need 60 cubic meters of gas per hour. Start with your HP/gas requirement and work backwards to get your component dimensions. The gas requirement (Nm3/hr) is in the first column in the Range of gas output section on the upper right side of the chart. Mine are line C. The chart stops at about 130 HP. I’m not sure about HP levels above this. The entire build has a 4 ft square footprint (16 sqft) with a 7’ tall cooler. You can check out the rest of this build in the Small engine section under “My first small engine run”.
Pepe
Compares the imbert specs with the actual numbers I had to work with. The exed portion is my new grate basket operated from underneath. Whoops, I was at line C but changed dh and h to line D specs with a new hourglass insert and basket grate (for better flow). The lower cone height was changed to 4 7/8". It’s not an easy build, but it’s not that hard either. The hardest being the need for airtight welds. I’ll be glad to answer any questions. Check out the Library for Gasification Basics. So there’s some food for thought.
Pepe
Hello MatthewM.
Welcome to the DOW.
Why can’t you use a huge envelope to make good motor grade gas for a small system?
You have been correctly answered that you have to have a very high maintained concentrated Temperature zones.
Just as important the internal before-fuel-gas flows have to be very specifically directed past a heat glowing maintained bed of wood charcoal particles.
Big engine supplying systems need larger area flow pathways; and larger volume of reduction reaction char beds.
WayneK has for years ran for hours his smallish engine generator on his large truck systems - AFTER the big truck engine has heated up the gasifier. One of the only raw wood fuels systems been shown able to do this.
The biggest downside to charcoal fueled systems is being able to make the charcoal without legally being hammered for it.
16" of storm front after storm front raining here since the 1st of October. We’ve seen the sun only three time in this time period. Be no sun dried wood now until into the end of next June. Chracoaling you really do need pre-dried wood input or lose 2/3rd your energy first drying, then in the charcoaling.
Read Wayne/Chris’s book, VesaM’s book, many other books, and you will see that a raw wood condensing gasifier system makes it’s own internal charcoals and remove out all excessive system unuseable, wood and airs moisture’s.
And since you were talking about a stationary power system do not be sidetracked by vehicle needs of the smallest, lightest system.
Example: a straight section of 20-30 feet of 4" cast iron drain pipe can cool and moisture’s condense out all of your generator system fuelgasses AND heat some shop/garage space too.
Regards
Steve Unruh
Steve; Are you purposely glossing over the fact that for wood gasification, you need wood down to about 10% moisture. I believe that I can make charcoal with wetter wood. It will take a little more time and probably make more smoke. If you take a piece of wood and make charcoal out of it, it will take the same amount of energy in a woodgasifier as in a TLUD . TomC
Not true… 10% is kiln dried wood. Most of us are running 20-30% regularly. Obviously drier is better.
Smoke is the bane of charcoal making, in any populated area. Nobody wants clouds of smoke.
Ok, my point being if YOU can make charcoal out of 30% moisture, I can do the same in a TLUD. Smoke?? I use a double barrel and get no smoke. I have seen the pyramid system work with out smoke. The more moisture you have in the wood of a gasifier, the less or poorer the gas, because you are using so much heat to dry the wood. The charcoal will make equal gas after it is made, so you don’t have that variation in the performance of your engine.TomC
Hi Matt, A stationary genset is a little different bird from a truck, but many things carry over. You mentioned maybe 10 Kw. I don’t know the horse power for that, but you do lose about 25% on WG so an over sized genset is an important consideration. I don’t know what your electrical plans are but the 318 I drive will burn over 1 lb/mile. Driving 50mph for instance will require 50-60 lbs of wood per hour. Those numbers will scale to an extent, but some will think they can go off grid for free, but don’t realize the “cost” in wood. Patrick Johnson in Africa had a good run with his genset and WK gasifier and makes a great read.
Rule of thumb is 750watts per hp give or take, so let’s say wood gas is 50% of that, so in very rough terms you need 2 hp per 750 watts.
