Wood Gas, a Commercial Plant now in Operation

Reposted as a reminder.. Wood gas and gasification in general has been in use for a long time..


How many Commercial Plants are in operation that we can study?

Many of us understand that producer gas has been around for a LONG time, there are many relics around the world that are testaments to the value of this gas, but at some point in history government subsidized electrical grids, and inexpensive petrol fuels caused these sources of renewable energy to be abandoned and forgotten. I offer the very popular ‘Gas Works Park’ in Seattle,WA USA  as our local example. The people of Seattle consider our old ‘Gas Works’ a piece of art.

Here’s a note from hatheway page:

One of the last west-coast gas works to be installed was the 1937 Pacific Coast oil-gas process plant at what is now Gas Works Park, at the extreme north end of Lake Union, in Seattle. This was a redevelopment of the older Lake Station of the Seattle Gas Company. As shown in Figure __, the open-air retorts are surrounded by a chain-link fence with informative signs. Distribution compressors are housed in a sideless roof and painted cheerful colors to serve not only as a full-size educational exhibit for machine enthusiasts, but for children to climb.





The variables in each marketplace creates a real challenge for potential investors/stakeholders to make an accurate assessment of a producer gas plant and whether it could provide economic value in their operation.   I have been frustrated by the lack of operating information, but now a friend in Malaysia shares the work of James Tan of ‘Trillion’ and their  commercial producer gas plants running in Maylasia  with happy stake holders, and owners.

As a student of Cogen plants, it’s very difficult to ignore the advantages of the turbo charged diesel engine as the prime mover, and I was quick to note that Trillion has adopted the turbo diesel in some of the operating plants in Malaysia. All parts are ‘on the shelf’, and the co-gen operator can make use of diesel trained mechanics in their markets.


There are more Trillion videos on You Tube, what I share here are examples.

Using an oil based fuel like transesterified palm oil for the ‘pilot fuel’ may be attractive in the Malaysian market and others. Here in the USA, there is interest in making the best use of used cooking oils, and there is a lot of interest in burning these oils as SVO because it avoids the use of ethanol, sodium hydroxide and/or similar chemicals and associated expenses in the transesterification process of the oil(s).

Here’s a UN link with some basic information


Typical Questions/ Concerns

Can we run with low emissions and acceptable engine wear?

Looking at the Trillion effort, it looks like there was a lot of effort put into traping and removing the tar, and bringin the gas back to ambient temperatures. After doing this, the gas passes through several filter to remove any particles or tars.

In some of the research projects conducted by ‘Engineers Without Borders’ EWB and affiliates, there is thought of using biomass methane or other low emission fuels to offer a higher return on investment in multifunctional platforms that are powered by the old Lister type engines found across Africa and much of the third world. If you are not familiar with the MFP, they are used to grind grains, corn, rice, pump water, and perform other tasks that might make the difference between life and death. What is the potential for producer gas in MFPs? Have any of the EWB affiliates tested producer gas with SVO powered MFPs?

Many Students of cogen are convinced the turbo charger is a distinct advantage when we consider these lower BTU fuels, as we can pack more of this fuel into the combustion chamber per power stroke, and operate closer to the designed power output of the prime mover. In some plants, I have heard of the use of spark ignition engines upsized to larger cubic inches to produce the required horsepower output.

In a co-gen setting, we generally have a lot of room to do things that may be an advantage in lowering emissions, and increasing efficiency. One thing that retired engineer John Laswell communicates in his articles on wood burning here is the moisture in our gasifier fuel must be driven off, and it takes energy to do this. He teaches that it is fairly easy to take a sample of our fuel, weight it, and then microwave that sample until it is dry and weigh it again. We can compare the weights and calculate how much energy we will use to dry our fuel in the gasifier, as the energy necessary to accomplish ths work ‘will not’ be available to power our prime mover.  I mention this because there may be an opportunity to use the waste heat of the cogen plant to lower the moisture content before the fuel reaches the gasifier chamber, and this effort could increase plant efficiency and lower the effort to clean filters, and potentially lower engine wear.

I notice on some forums, there are discussions about wet fuel being an advantage as the high temperatures ‘crack’ the H20 to form hydrogen and Oxygen and form a good part of the fuel, this is just an example of the myths that circulate in threads of discussion about producer gas.

One of the advantages of a dual fuel prime mover is the ‘pilot’ or primary fuel can be set up to assure a constant power output. When the producer gas falls off, the primary fuel takes over.  When there is a fixed load like we might find in a water pumping station, the ‘position’ of the fuel rack on the injection pump (monitored by a machinist’s dial gauge or similar) might give us an inexpensive field reference as to how much fuel is being  provided by the producer gas unit, and it might give us a comparative tool to access the different fuels available, their moisture content, and the return on our efforts to further dry these fuels. I have seen useful dial gauges for sale as inexpensive as $7.00 USD.

What may be even more important in the dual fuel prime mover, it that we can schedule work to keep the gasifier running, and not have the requirement to have an operator sittign on the equipment every minute. Once an operator becomes familiar with a fuel, he may schedule visits to the gasifier at 5 hour intervals to add fuel, or perform other maintenance, and if the producer gas falls off prior to his return, the plant continues to operate. This may be far more important in a ‘generator’ plant where it more important that the power plant remain in service.

There are ‘on the shelf’ throttle position sensors’, that could give us reasonable data out of a power plant, if we sample throttle position, and monitor KWhs of production, we might easily populate a spread sheet. If the plant were to record the type of fuel used in the gasifier, and the labor hours associated with maintenance and labor hours to charge the Gasifier, it would be easier for a plant manager to make a decision as to whether this investment is right for his operation. It’s possible that qualified labor is in the area to complete other work, and there may be no additional labor costs to charge and clean filters.

The Trillion operating site has certainly increased my interest in producer gas. These producer gas hobbyists might not be crazy after all…

As for engine wear. What is acceptable has everything to do with the cost of replacement parts, and the labor to replace them. The older stationary engines were designed from the ground up to facilitate quick rebuilds (in place), and in some designs you could replace wear parts in less than two hours. This fact, and the reasonable cost of parts could make all the difference in co-gen. I believe there are plenty of reasons for the EPA to allow us to have access to the stationary prime mover designs they have currently banned from our shores.Many of the newer designs are not economically rebuilt, or at least too few of us know of the prime movers that can be rebuilt at reasonable prices. This could put our farmers at a distinct disadvantage.

Please consider sharign any links or information regarding other producer plants that might be comercially viable.

All the best,

George B.

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20 Responses to Wood Gas, a Commercial Plant now in Operation

  1. George B. says:

    I received this in email.. a shy person, who apparently didn’t trust that his identity woud be kept secret? I’d like to see evidence this is true, seems real easy to me, just run too identical loads of bio mass (carefuly weighed.. . one watered down real well after the weigh, one as dry as possible. Run the batches and measure the work done with the producer gas. Perform this experiment with a person present that knows how to use a power meter, a generator attached to the prime mover.

    Here’s the email:

    As you probably know i am also a student and avid research of woodgas and related technologies and also have long been a proponent of dual fuel operation of a diesel engine.

    After talking to you today, I thought i would state my position on water dissociation in the gasifier process

    this has long been a point of contention, does the water turn to steam and the superheated carbon in an oxygen
    deprived region of a gasifier rob the oxygen off the water molecule releasing hydrogen to combine with the CO
    and methane given off in the gasification process? apparently this is true

    there are many references to this as being a fact going back over 100years ago, the engineers understood the process
    in applications like gasworks park.

    there are many technical papers out there from universities, research groups and several books that cover the subject in depth
    topics like “water gas” will google up lots of info about the process.

    also it has long been known that if a boiler (coal fired) ruptures, you of course get a huge bomb on its own, but the dissociation
    of the water molecule and release of large quantities of hydrogen magnify the explosion much more so that gas fired boilers produce
    under similar sizes.

    having said all that there is an old russian gasifier that is quite good at harnessing the dissociation of water, it uses as cut green wood
    right out of the forest to run pony motors, and tracked log skidders and apparently makes excellent power.

    the key is getting the temp in the reactor region high enough, have enough carbon glowing and starved for oxygen, and then admitting
    steam which already has had all the btu’s added to it to make it steam (this way it does not markedly reduce the reactor region temps)
    then the hot carbon steals the oxygen and releases the hydrogen…

    i don’t think our boys down in california can accomplish this task, at least not in a continuous or repeatable process, probably hit and miss
    it comes and goes, and so does the quality of their producer gas.

    please at your convenience do a google for research papers/books and other references to water gas, producer gas dissociation of water, etc. i think you will be surprised that the theory is not only a good one, but something that was practiced back in the day.

    in closing, you made a valid point that it take more btu’s to boil off the water, to get the steam to make the damn thing work, and this is true, however what we are after is a higher quality fuel, and who cares if we have to burn a bit more wood, coal, peanut hulls, or whatever in order to get the water converted to steam and get the reactor region up to the required temp to support the dissociation
    of the steam.

    a properly made plant can recover a significant amount of the waste heat anyway i suppose, in cogen mode.

    the problem with the california approach is they have no way of knowing what the moisture content is, and how stable that number
    is over the course of feeding in more material, i suspect it is a moving target.

    the other thing is a reactor that is running hot enough to dissociate the water molecule, is hot enough to crack most of the tars into
    a number of combustible gasses, negating the need for frequent filter changes, my bet is your far east gasifier guy has got this worked
    out to a science, and my bet is he is also dissociating the water molecule from the feed stock too.

    i think there is much more to gasification than we were once aware of.

    • Andrew Schofield says:

      I have seen results of gas testing a friend had done.
      Surprising percentage of hydrogen in producer gas.

      It has been a while since I had a look around your site George.
      Are those east indian engines available in the USA?

      • George B. says:

        Your post will certainly raise questions. Readers will likely form the question, why can’t we separate these gases and store the desirable ones? We know that there are commercial enterprises where our atmosphere is pumped into a tower, and
        separate gases are taken off the tower according to their specific gravity. What happens when these gases are compressed in the same way atmospheric gasses are compressed? Are there any biological organisims that are fond of a gas that may not contribute to combustion?

    • Mike says:

      when we spoke on the phone I’d mentioned other uses for the parts we spoke of. What I didn’t elaborate on is using the left over char from the gasifier to do dissociation of water under extreme heat conditions. A small amount of carbon can be used under the right circumstances but the temps must be high. I do also have 100 tons of coal to play with. I’ve been talking to a certain guy in England who is very much involved in Lister engines and woodgas that is interested in many of the said Lister mods. I haven’t spoken to him as of late but he will be included in any advances I do involving the Lister. He is an EE with experience building Arduino controls/ data logging. He’s been a leader of one of the projects I was associated with.
      Check out this little link for a taste of where I’m going with cracking water using carbon. I spoke to you a good many of years ago about running the Listers on Hydrogen as I was pretty sure I could produce huge amounts of the stuff. What I didn’t tell you at the time was,” It’s going to be mixed with other gasses.” There are many types of gasifiers and I can almost guess who wrote that last post 🙂 There is much room for improvement and automation no matter what type of gasifier we are playing with.

  2. George B. says:

    Hi Andy,

    AS mentioned elsewhere, we need a prime mover than is easily servicedd and rebuilt in place, that is what our stationary designs are all about. There are two entities that are selling either kits or complete Indian engines now. I think I’ve shared who they are on the utterpower FB page. remember Andre Dancause? He’s a favorite French Canadian that likes to tinker.. Here’s page about his turbo 6/1, will this help us fuel with producer gas? https://www.utterpower.com/turbo_6_1.htm

  3. dave says:

    My family inherited one of the old MGP’s from the Seattle area and all the waste that came from them (cPAH’s, PAH’s, DNAPL, etc. found at the 100x or 1000x industrial clean-up levels for MTCA standards). This waste made our property worthless. In doing research on MGP’s we discovered that the waste produced by these plants was astronomical. A great site to look at in this regard is… http://www.hatheway.net/

    Is gasification a safe way to proceed? Were gasification plants on tidal flats or rail lines for a reason or was it coincidence? I have not looked in depth at current theories on the gasification process and can only assume the manufactured gas plants of old flew in the face of any contamination concerns.

    Please don’t read me as an EPA advocate. I’ve just seen, smelled and felt the waste’s from numerous cores taken on this property to know about the coal tars and the result of coal gasification and am curious to know what byproducts wood gasification produces.

    • George B. says:

      Anyone over 60 years old remembers when all kinds of waste products were considered valuable weed control, a lot of people dumped this crap anywhere they didn’t want weeds to grow.. There’s Rail Road property that hasn’t produced a weed in years.. and some still think that’s a good thing. There are a lot of environmentalists that would quickly throw the baby out with the bath water. I have little doubt in my mind as to what townspeople of the day did with all that valuable creosote and other by products, they dumped it where ever it was handy, and I would imagine there was a lot of really bad stuff that got gasified ,versus hauled off to a different dump…Old roofing, tar, wood painted with lead, wood treated with arsenic, old railroad ties, and God only knows what got made into gas, why waste it was likely the thought of the day… The gas plants were little different than dump sites of the day… what would we expect? When I was a kid, I saw a lot of waste barrels just dumped over to leech into the ground.
      There are a lot of environmentalist that only have one size paint brush.. well, actually it’s a broom. I think we need to apply a little common sense in our comparisons, and we need remember that the gas works WAS the dump in a lot of towns.
      Let’s be a little more scientific than these people and remember,… the goal is to use clean bio mass, NOT all the crap tossed into the gas works 100 or more years ago.
      No one in their right minds wants dirty air or contaminated soils. I think if we could dry some of these rabid environmentalist to around 8% moisture content, they’d likely make a good gasifier fuel, and it might be good for the planet and humanity. There are a lot of people that die each year because they are deprived of simple things like refridgeration that might keep vacinations and other medications on hand. Some environmentalists think that bringing small power to the thrid world is wrong. I think they need a hand up, and a small gasifier might be exactly what they need.

    • George B. says:

      As for the gas plant and the rail road.. who in their right mind would move heavy industrial stuff across town VS build next to the rail road? What you going to use to drag all that heavy iron across town, and why? As for tidal flats, I’d expect you would put the gas works in the butt end of town, I can’t imagine the Mayor or the judge wanted it across from their white picket fence. How desirable were tidal flats? Did they have to move the Mayor out to build the gas plant there, I bet not… likely the butt end of town..

  4. mobile_bob says:

    hey George, its me the shy one, lmao!

    i didn’t see the response box so i just sent my comments via email…


    i decided to go back and do some more rereading and i got it mostly right, but as they
    say the devil is always in the details.

    dug out my copy of
    the internal combustion engine in theory and practice
    by: charles fayette taylor
    volume 2
    published MIT press
    isbn 0-262-70027-1 paperback version
    pg 127

    the following describes the dissociation process

    ” artificial gas is made from coal or petroleum by various methods, usually involving combustion of CO (carbon monoxide), together with the dissociation of water to yield gaseous hydrogen”

    in the following paper, more of the process is explained, however the dissociation thing is limited to what water is bound within dry wood.

    German ideas on improvements of wood gasifiers
    Summary in Teknisk Tidskrift of a thesis by H LUTZ
    published in ATZ. Editor C V NORDENSWAN
    English translation, 2000, JOACIM PERSSON
    (publ. Tekn. Tidskr.) September 20th, 1941

    google will pull up the paper, there is also a companion paper

    Gasifier efficiency
    By professor E. HUBENDICK
    English translation JOACIM PERSSON, 2000
    Published in Teknisk Tidskrift, December 20th 1941

    this paper further explains the processes involved

    what is interesting is for dissociation to work, the water must be superheated steam
    so that the water molecule can absorb very little extra heat in the reduction or reaction zone of the gasifier, (and)

    the zone must be (iirc) somewhere in the region of 1100 degree’s which coincidentally corresponds nicely with the temp required to also crack the tars produced in a gasifier
    thus releasing gaseous volatiles.

    the 64k dollar question is, can a gasifier reach these temps? can the superheated steam remain in the reduction zone long enough for dissociation to take place? can it be done with biomass and not coal? and is the superheated boundary layer where the dissociation takes place hot enough with wood charcoal or other common biomass for the reaction to take place?

    apparently from charles fayette taylors book there has been much research and gas analysis to prove that this phenomena takes place, however it is unlikely a diy’er would have access to such test equipment to determine whether his gasifier did or did not provide the same results?

    from what i have read it appears to me that the trillion gasifier likely gets up to these temperatures as evidenced by their 2 week filter change intervals, they could never get there if their unit was cooler as there would be much tar clogging up the works.
    for something to last that long between servicing the filters supports the theory that they are running at or above 1100 degree’s in the reduction zone and cracking those tars, i can only assume that they are also dissociation steam molecules and freeing up H2 which improves the quality of their woodgas, in two ways

    added btu content of the fuel via increased hydrogen %, and reduction of nitrogen in the gas as there need be less air taken in to support combustion because of dissociation providing extra oxygen in the reduction zone.

    as you know i read everything i get my hands on on this and a few other subjects, however i shy away from diy’er reports and other anecdotal reports in favor of professional publications and published papers from folks that have all sorts of alphabetic stuff going on after their names. i can’t imagine that folks at many of the worlds leading universities would have it all wrong.

    but then again, we got quite a few that bought into AGW, so who knows?
    bob g

    • mobile_bob says:

      btw, just wanted to add the following

      do we really care what the efficiency of the gasification process is “if” we are buried in cheap or free bio mass fuel stock to feed the gasifier? likely not, if we need to burn a bit more, or maybe even a lot more to dry the feedstock then maybe that is the compromise we accept? maybe we accept a lower hp output from the prime mover because the fuel wasn’t as dry as we would like it to be?

      if it runs the generator and provides the power we need, no one will probably care too much about efficiency until it gets bad enough to require enough extra work packing in more fuel.

      if we have to buy the feed stock, then all bets are off, we likely better go for the drier stuff to start with, or figure a cheaper way to dry it?
      bob g

  5. George B. says:


    I think the test I proposed earlier would be of value to experimenters. Carefully weighed bio mass fuel charges. Bag each of them, dry one in a vacuum chamber with heat added. Take the other one and add water to your heart’s content.

    Charge the gasifer with each prepared charge and measure the KWH production of each charge. In this test we set aside all the therory and study the practical result.
    I keep hearing soem people say wet material is better, lets prove it.

    Till proven, I see that we need comitt energy to boiling off the water, and once we know the moisture content, we can calculate how many BTUs we need to do that.
    John Laswell has written three installments on wood burning, I suggest his articles applies here.

  6. mobile_bob says:

    i tend to agree with you and mr. laswell as it pertains to burning wood, however
    we are not simply burning wood for heat, but rather converting one fuel source (of low value) to another (of higher value) that is more easily burned in an engine.

    it would seem that dissociation of a steam molecule within the intense heat of the boundary layer of carbon at ~1100 degree’s is plausible , if we consider that we can dissociate a water molecule with a simple 1.5 volt dry cell battery,, (efficiencies notwithstanding). we are not talking about splitting an atom, we are talking about splitting a compound which doesn’t require the heat of the sun or a fission reactor?

    i would also wholeheartedly agree that wet wood feedstock is not likely going to work well in a gasifier, (of common design), the russians (uncommon) design while able to tolerate green wood uses a lot of the process heat just to dry the feedstock. while the russian units are thought of as very inefficient, perhaps efficiency is of no concern when you are in a forest taking down tree’s and have mountains of branches, twigs, and bark to feed the thing?

    my only point is you will never get the wood to zero moisture content, it is far more likely there will still be at least 10% water content and that will be subject to dissociation.

    likely never going to see this happen with wet wood however, wet wood gasification is likely just a steaming, smoke belching, wet tar producing engine destroyer on its worst day, and not much better on its best day with a lot of screwing around trying to keep it working. at least in any of the gasifier designs that are not patterned after the russian unit.

    just getting a gasifier working to an acceptably clean level sufficient for consumption in an engine is tall enough an order to start with, and then getting it to deliver gas of consistent and sufficient quantity and quality to make stable power is another significant step. working out efficiencies likely is way down the list of priorities especially for folks that just need a functional unit and that have ample feedstocks that are virtually free.

    or so it would seem to me

    bob g
    ps, if i need to send you a check to help cover the cost of extra bandwidth and/or storage let me know.. 😉

    • mobile_bob says:

      ok, i promise to shutup after this


      if you look at these gasifier plants, admittedly they are large scale megawatt class
      affairs, however they are using woodchip as a fuel, one lists 9.5% moisture content, while another processes 50% moisture feedstock, however

      take a look at the air and “steam” injection into the reduction zone of these gasifiers, and look at the much higher hydrogen component of the resultant gas (20% when most gasifiers are typically 5% or less).

      one might conclude that admitting steam might result in dissociation of the steam molecule and liberating hydrogen gas? where else is the increase in hydrogen as a percentage in the wood gas coming from, and why would they be injecting steam into the reduction/reactor zone if it weren’t to supply a controlled amount of water molecules to this high temp region for dissociation to take place?

      more questions, and few answer have i
      bob g

      • George B. says:

        Bob, this is a good contribution to the thread… In the slide overview, they mention the Novel plant using waste heat to dry the gasifier material. Regardless of what steam injection might do in the gasifier (or) another process, My focus has been on DIYer comment and the typical mention that wet biomass can boost the quality or quantity, or both of the gas. I don’t suggest I’m anything other than skeptical.

  7. Andrew Schofield says:

    Dave, Bob, George,
    The most useful books I have read on wood gasification are available at the
    Biomass Energy Foundation bookstore.

    My mobile 30 kw plant uses 3 pounds wood per kw/h.

    I produced woodgas carburators for these engines featured on you tube:

    I am developing this machine for wood processing:

    Andrew Schofield
    Renewable Fuel Systems

    • George B. says:

      I’d love to see some more operating data added to your You Tube videos, very difficult to see the multimeter, or get an idea how long your plant might run on a charge, etc. I think you could put those facts right up front, and get more attention for your noteworthy efforts.

  8. George B. says:

    One more note regarding producer gas plants of the past. We have far too many people in our country who think every back yard is the same as theirs, they also think that most eveyone holds their opinion and values. I don’t suggest Dave is in this group.

    Dave mentions a contaminated site, I’d like to mention one in the Kent Valley, Wahington State that made National News, now a superfund clean up site. A man from a Foreign Country started a wrecking yard here, and turned it into a dumping ground. God knows all of what he dumped, but there are still monitor wells, and plenty of pipes underground installed on site to capture materials that are lighter than the ground water and transfer them to a tank to be properly disposed of. Dave Binford works closely with EPA and environmental authorites, and I’m sure he’d fire anyone in his employment that got caught dumping anything on the ground.

    I think the guy might still be in prision, and Binford Salvage owns the property now and of course they have been far better stewards of the property and environment. It has never been a problem for me to identify the past operators as the problem, VS the operation.

  9. George B. says:

    And here we are beyound 12/12/12, near the end of time, and is there yet.. one generator running on wood gas here in the USA with continious power out figures published and witnessed? Vehicles and idling engines are one thing.. generators.. well that’s where we might see the value in owning a wood gas plant..

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