Well, even though I'm working on research with a gasifier at work, I decided I needed one of my own. So, this afternoon I ordered a GEK.... the Gasifier Experimenters Kit... from www.allpowerlabs.org. I feel like a kid at Christmas! I can't wait for it to arrive!

I also was excited to read about a college course being offered up in Minnesota on Biomass Gasification. That excitement was hard to contain after I called and found out more about the class. Three weeks, three hours of college credit and guess what they'll be using as a hands on gasification teaching tool? Yep... the GEK!

By the way, they got a grant that will pay tuition and lodging in the dorm. I'll put a couple of drums of WVO in the back of my truck and head north for the last week of May and the first two weeks of June.

Just wanted to share some exciting "renewable energy" news in my little green world.

Wow sounds awesome now get working on making some methanol from the syngas. :-)

I Hope to read about your experiance with this gasifier, I have read over there web pages and sort of dismissed them as a bit more green than teck. the gasifier is somewhat unique in it's design due to the gas connection cooling tubes. Seemed like most of there testing was done burning crushed walnut shells. My concern with the design is with soot clogging, hope I am wrong. Haven't done any testing with our gasifier at all since last fall, too many projects, we did steal there welded-up design for a cyclone though.

There are some striking similarities between gasification of woody biomass and the use of vegetable oil as a fuel. Thinking back five years ago when I first got into veggie, I shake my head at how I first did things. From collection to filtering to my first truck system... how things have changed! Even how we make biodiesel at home has been refined a LOT. Together we've learned tricks along the way to streamline each step of the process.

Today I find using veg oil as a fuel is not only easier to do but the quality is much better. I want to do the same for small scale gasification. Process and product refinement are both essential to getting small scale gasification out of being a hobby into a viable form of renewable energy.

With regard to the walnut shells, that's an easy feedstock to use. Same with charcoal. But, we don't have walnuts in my area and charcoal is too expensive. You can use just about any type of organic material as fuel but it's like the old biodiesel vs. WVO debate. What do you need? Short runs to and from work? Go biodiesel. Lower up front cost but it has a higher operating cost down the road. Or, if you drive longer distances each day, you can spend a little more up front adding a tank and all to the vehicle but your fuel cost will essentially be nothing down the road. More up front expense but lower operating cost in the future. It's the same with gasification.

Using pulp mill grade wood chips is like making biodiesel. They are available in my part of the country and it's relatively easy to design a gasifier for chips (less up front cost). But, these chips cost money. Cheaper than some feedstock but still expensive in my book. My goal is to invest a little more engineering (up front cost) and incorporate a little more process equipment (think: FPHE, FASS pump, extra filters) so we can use storm debris and tree trimming biomass as a feedstock. Just like WVO... a little more engineering up front for a really low cost feedstock.

That extra expense will have a break even point a little farther down the road but the long term operating costs will be less.

As a community, we've solved so many 'real world' obstacles to running veg oil as a fuel. Five years ago I wouldn't have considered trying to teach even my moderately mechanically inclined brother to run on grease. Now, I have a friend who is a lady lawyer successfully spinning her grease clean with a Dieselcraft and cruising to work each day in her Mercedes 300TD. We've brought this "industry" a long way in a relatively short time. I see the same potential for small scale gasification.

Just like the first time you experience a vehicle exhaust that smells like someone is cooking, it is likewise exciting to crank up a generator on nothing but woodgas. No other fuels. Ours at work actually started better on woodgas than propane.

My ultimate goal is to use this technology for storm cleanup and to take to third world communities where we can convert whatever they have available into energy. I'm even working with some chemists on renewable methanol from woodgas so biodiesel won't cost as much.

When it's all said and done, it's all about the AVD... the Arab/Venezeulan Disconnect. I don't want to buy one drop of oil from people who hate us as a nation.

The problem I find here with storm downfall is infrastructure, the powers controlling the big cleanups won't let you anywhere near the downed wood for liability reasons. We had a BIG ice storm a couple of winters ago, a neighboring big city hauled 5 yard dumptruck loads of wood 24/7 for over 5 weeks, they even rented a farm field and got EPA wavers to allow them to burn it continously for over 2 months, think they would let you have any, NO WAY, what a waste.

Locally it is easier to get free wood chips than it is to get limbs and trunks, both the village and the local utility companies chip everything under about 12 inches. the village won't allow you to use chainsaws on there property to cut up the big pieces so you can handle them, and they won't legally load the big pieces into your vehicle for fear of being sued for some sort of damage. I have a friend here that owns an equipment rental company, once we posted a copy of his liability insurance with the village they allowed him to use his skid loader to load his dumptruck with free chips.

Problem with big pieces is that you have to chunk them up into littler pieces, takes a lot of time and handeling. The most practical way I have contrived to do this is to cut the tree trunks into 3-5 inch thick "rounds" and then cut/split them crossways into the appropriate sized blocks. I do this for my small woodstove using a chainsaw to cut the rounds and then score the blocks using a skill saw, then split the blocks off using a hammer and chisel, takes a lot of work and time. The next possibility is to cut the rounds and then make up some sort of a wide hydraulic splitting wedge, haven't built this yet.

For a home/farm sized gasifier wood chips are easier but need to be classified into a narrow range of chip sizes, too small like sawdust clogs up the gasifier vapor flow, long slim slivers cause bridging that stops the fuel chips from feeding through the gasifier. All this can be overcome but it all takes added time and effort, it also usually needs someone to constantly watch over the process, more time involved. The ideal situation is to process the wood into compact and dry uniform fuel pellets, once you have relatively uniform pellets it is then possible to run the gasifier relatively trouble free. If one had the need for the quantity of fuel I think the easiest way to process the sawdust into pellets would be to use the exact same equipment that is used for making charcoal briquetts, the briquetts won't be as compact as pellets but they literally fly out of a fairly simple briquette compacting machine, there are also chinese made extruding machines available that poop out a continuous 2 inch diameter sausage of compacted sawdust.

John deer used to make a hay cuber type combine, these have been used to produce 1 1/2 inch cubes for fuel using any combination of biomass, the cube is not all that compacted but compacted enough to feed through a gasifier without falling apart in the fuel hopper.

Check Youtube for short video clips from Chinese manufactured briquetting and extruding machines for sawdust, there used to be several.

Are the gasifiers you are working with batch loaded or continuous feed, I find several small continuous feed units on the net that burn wood chips but they fudge there advertising a good bit by NOT explaining how much time and work has to go into the clasifying of the chips. Looking closely at the pictures of there gasifiers will show wood chips of VERY uniform size and shape, most of the chips also look like they were chipped from kiln dried construction lumber rather than storm downfall, very bright yellow and absolutely no pulpy sawdust chunks or long slivers, just 5/8 to 3/4 inch square by 1/4 inch thick uniform chips.

One style of wood chipper looks like it might make less work out of making "blocks", this is a "screw" type chipper, they are rare in this county but are still made in scandinavia. They were imported here and in Canada during the early 70's so a few used ones are around but I have not seen one on Ebay ever in this country, there was one on Ebay UK recently that sold for about the same as an industrial chipper here, around $4000.00. These screw chippers are available with different sized screws to make different sized blocks but they still make a good bit of the long thin slivers that need to be screened out, BIG gasifiers can apparently handle run-of-the-chipper chips with much less problems than smaller gasifiers can but they are a LOT bigger than what I want to have to feed.

The gasifier I just bought is a research unit. It comes as a batch feed but they have plans available to fabricate a continuous feed. In my opinion, continuous feed is essential. Who wants to go out and add fuel every couple of hours? It's not as easy as throwing a log onto the fire. The gasifier gets full of smoke and you have to be careful when opening the lid.

We have lots of work ahead of us regarding the fuel. I've tried pellets but found them troublesome. A friend who has a pellet mill can also make what are essentially "wooden cigars". I'm thinking those may hold more promise. Cubes also sound promising.

One gasifier won't fit all needs no more than one WVO fuel system will fit all diesel vehicles. The trick will be to match the internal configuration of the gasifier AND the operation process to the feedstock. One way or another, I do feel we'll develop ways to use chunks (cut up limbs, small logs), pulp grade chips (easy), dirty chips (from storm debris chipping, difficult), sawdust and even sanding dust. On the last two, pellets and cubes are my best best. Same goes for chicken litter (and other manure) and municipal solid waste.

I feel an internal stirring mechanism (rotating vertical shaft with arms sticking out like a turnstyle) will be necessary to inhibit bridging on smaller and less uniform feedstock. Pulp grade chips or wood blocks flow fairly well through the gasifier with just an external vibrator. Pretty much everything else will take more work. It will take a combination of internal stirring, nozzle configuration and tweaking the airflow to make it work well.

Regarding not being allowed to harvest these downed trees, isn't it sad that renewable energy and protecting the environment has to take a back seat to fear of a lawsuit? I do feel we'll get over that hurdle as more find out we can convert what is now waste into renewable energy. This will change.

I like the sounds of your screw chipper. I haven't had a chance to search for it online but please post a link if you run across something so I can know what you are talking about. I still have much to learn about the chipping/grinding/pelletizing and cubing side of the market.

You are right that everybody wants uniform and more expensive chips. That's why I want to invest the energy into being able to handle the 'dirty' chips. Just as I spent a little more time and money to burn WVO, I feel this is the way to go. More up front time and money but lower cost down the road.

Screw chipper links --

This one is just a one page description.

This links to the FLUIDYNE tech article archive, click on the second article down on the left of the page titled "Laimet screw auger chipper", they did a test and this article shows pictures of the machine and the different sized blocks it makes. The other articles are also interesting reading.

This goes to the Laimet screw chipper sales web page, there are several different sized chippers shown with detailed info. There is a Laimet dealer in canada.

This links to a 4 page PDF of testing of two older screw chippers.

This links to a web page for a small town extruder type pellet making setup, they are using waste paper as there feedstock. Even they are hampered by bureaucratic BS, they have to mix there paper pellets with coal because to burn only the paper pellets they would have to get a "waste incinerator" liscence from the EPA.

Thanks for those links, Tim. I had seen all of them except for the last one... but that one was the most interesting!

Don't you love how they have to keep burning at least a little fossil fuel for EPA reasons? Go figure. Hopefully, hurdles like this will be less and less as alternative energy through biomass becomes more known.

One way or another, I DO believe we can engineer the use of waste biomass as a feedstock. They always said you couldn't use SVO or WVO as a fuel... but we're doing it. I explored using a spinner type centrifuge a few years ago but they said it couldn't be done. Then someone (not me) had the idea of heating the oil to lower the viscosity and now lots of us use Dieselcraft and other type spinner centrifuges for even better filtration.

I've learned not to say it "can't" be done. "Impossible" just takes longer to engineer.

Missouri is somewhat unique in there waste handeling, the state legislature demanded a 40% reduction in waste going into there landfills, there are several communities now doing paper pelleting for there municipal heating fuel. They are burning them in boilers for steam rather than gasifying them but the pelleting is the same.

Northwest Missouri state University at Maryville Mo. seems to be a leader in burning wood chips and pelleting paper and a mix of paper and pig manure.

This links to an overview article about there use of alternative fuels to heat over a million square feet of buildings on the campus. I have not yet had any luck finding any detailed research papers on there website but I keep looking, I have found several other general articles about them on the web, one article indicated they have modified some older farm equipment to do some of the chopping, mixing, and pelleting. Again, they are making steam by burning in a slope hearth furnace rather than gasifying but at least they have managed to create a viable collection network for storm downed wood chips and waste paper that covers a diameter of several hundred miles around the university.

This links to another article expressing the universities intent to expand into several other areas of alternative energy, including small scale gasification.

Thanks again for great links. By the way, Middlebury College in Middlebury, VT, has installed a gasifier for heat and I think electricity. They are using wood chips.

I want to get some of those paper pellets to see if they will hold up in a gasifier. I'm afraid the density won't be great enough to stay together. Instead, they may just fall apart and contribute to bridging. But... we'll see.

I wonder what role our biodiesel glycerin might play in the pelletizing scenario. Maybe as a binding agent? What do you think?

By the way, one cousin of mine used to be on the Missouri haz waste commission so I'll see if he has any contacts in his state.

Paper pellet strength - I think the paper compacts pretty dense, reading about the paper pelleting done by another Missouri town (can't find the link just now) they store there pellets out doors, the picture showed several house sized piles, they indicated that the moisture content of the rained-on pellets was never more than 2% higher than for the control pellets they kept stored inside, they have to be pretty dense not to absorb rain water. The paper has had a lot of it's original high heat energy fuel components removed during the paper making process so the pure processed paper has considerably less heat energy than wood.

Glycerin - Might just work, in reading discussions from folks that operate the small 2 to 6 bushel/hr home sized wood pellet mills, they sometimes use veg as a binder and always start and stop there mills using sawdust that is pretty gooey with veg to lubricate the pellet dies and to make sure the material in the pellet dies does not set up like concrete once the machine cools down. From memeory I think the glycerin burns clean at a temp above 1000 deg f, the gasifier char section wants to burn at someplace between 1000 deg f and 1400 deg f so the glycerin should pretty well all get converted to carbon monoxide as it's vapors pass through the glowing char. Not sure what would happen to the excess caustic at that temp, it would likely first be converted to inert mineral salt and carbon di-oxide, then the carbon dioxide should be converted to carbon monoxide as it passed through the char, the salt would melt into a liqued and might create a problem by solidifying the ash into clinkers in the bottom of the char section as it cooled, don't know. Not really a lot of ash left over if the gasifier is running correctly but it depends a lot on what is being burnt. Some biomass grasses (also corn) produce a good bit of ash and also release minerals like calcium, these minerals also melt and cause clinkers when they cool and solidify in the ash, from what I read this is the main concern when burning grasses through a gasifier.

A couple days ago the early morning TV farm report had a segment about a walnut grower in California that was burning his mountains of walnut shells through a big gasifire and producing all the electricity he needed to run the orchard operation, they then used the fine carbon ash from the bottom of the gasifier as fertilizer around the trees.

There next project was to somehow use the walnut shells to produce fuel for there farm equipment but they did not elaborate on just how they intended to do that.

The gasifier was good sized, maybe 5 ft in diameter and 20 ft tall, it looked like a rocket motor, lots of odd 2-3 inch diameter tubing running everywhere over the outside? The gas was used to power a diesel genset. The entire setup was built by the Community Power Corperation (CPC), these folks seem to be the premere designers/manufacturers of small gasifier powered electrical generating units. There 15KW unit is batch fed but there 50KW gasifier is continuous feed, mostly with wood chips, but it is there pictures of the wood chips that I refered to earlier in this discussion. This links to an article from Mississippi state university where they were testing a small CPC continuous feed gasifiers, sure looks like graded construction lumber chips to me. Looking over there web pages It looks like all there projects are funded by commercial or government grants one way or another.

I've heard about that gasifier in California. The word is they are working on Fischer Tropsch with hopes of generating liquid fuel (diesel) this summer. But, easier said than done.

CPC built the gasifier in use at a Forest Service Ranger station in central Louisiana. It uses "clean" wood chips to generate 25kw of electricity. The wood you were looking at is probably an example of those. They are cut for use in a pulp mill with a specific size and cut angle which helps in flow through the gasifier. The BioMax 25 I looked at does not have internal agitation, only an externally mounted agitator/vibrator. Dirty chips (such as tree trimming or storm debris) would likely bridge.

The BioMax 25 is a continuous feed, open to the top. The air comes in through a variety of ports circling the gasifier and at different levels of the process. That way they can adjust the amount of air entering the gasifier so as to manipulate the temperatures. It looks bigger than it probably is. The BioMax 25 is less than 3' diameter, not including all those pipes and valves. It does look a lot like a jet engine, though. However, there is nothing on the inside. Not even a plate restriction... just a straight through tube with a number of air inlets at various levels.

I know of a company that tried to buy a gasifier from CPC but they didn't seem interested. A research scientist (not associated with CPC or the BioMax installation in Louisiana) later told me it is about the bidding process. So long as CPC only sells to research projects and does not sell on the open market they don't have to compete on a bid list. The scientist explained to me that as soon as CPC sells to the commercial market, the other projects now become open bidding. As it is now, the grant specifies a BioMax from CPC without having to face competitive bidding. That's just one opinion. Besides, they do have a neat system. Good looking and very well engineered. Impressive.

"clean" chips -- Your description fits what I see in there pictures, didn't know there was anything like these used commercially but that would explain how they can get away with not explaining the chip prep. Enlarging and tweeking several pictures of there chips shows just what you described, very uniform sized chips 3/4 to 1 inch square by 1/4 to 3/8 thick with the cut ends having a very clean 45 deg slope angle.

I suspected there was a reason all the articles about CPC projects were real carefull to describe them as government funded research projects. They put out a lot of PR articles that seem to have info in them at first glance but in reading them in detail there is nothing technical actually being explained. I have found quite a few Gov conferance articles that give final-report type overviews of the equipment and projects, from reading these, and from inspecting there pictures closely, I suspected there gasifier was basically a refined version of the FEMA design, no hearth, no throat restriction. This is about the only design that I have read about that allows continuous feeding into an open top that has a low height. They seem to have it ironed out fairly well as there are apparently several units running successfully in widely different environments, they seem to have the operation automated well and they package everything nicely.

I have read about one somewhat different open top design in that the upper hopper is several feet long and of a small diameter, seems to block the outside air enough through the chips that they could use Imbert type pyro and char sections. I never have figured out just what type of gasifier the big 50KW unit in the philipines is, there are a couple video clips on youtube of it running. It is a huge open-toped tank maybe 10 ft across, and there are several other vertical tanks used in the progression of the gas that is being made from burning local tropical fruit or rice hulls.

I did come across one article a couple years ago showing something like a 10 KW gasifier and diesel gen set that was a continuous top feed unit, the pictures showed it being fed unclassified as-chipped storm downed chips, the chips were dirty brown and obviously contained fuzzy sawdust chunks as well as long thin slivers, they likely had been dried. The article said the system had been developed by a couple of young guys who were brothers but I never saw anything about it again.