Storing woodgas

General Discussion
#61

I agree with what you are saying, I wouldn’t recommend at all trying to run anything directly on retort gas, I think that would be certain engine death given the large tar production.

But, considering storing the resulting gas in a large volume container, as is the point of discussion of this thread, not for mobile use, opens up different considerations, and should mitigate the nasties. Given how mechanically simple a retort is compared to a gasifier, for some applications I think a retort might have advantages.

For welding gas or special purposes, I believe it’s more feasible to separate CO 2 from a gas mixture than nitrogen, although that’s already an industrial pursuit.

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#62

I think I have posted this link before, but here’s one way you can get woodgas stored:
http://stakproperties.com/index.php?p=3_77

I wouldn’t do it, but --------

Pete Stanaitis

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#63

Pete, interesting but kind of expensive. A few years ago if figured that I could build a light weight trailer with a large gas bag to get me between my place and the parents, 2 miles one way. Don’t recall if it was round trip or one way. Well anyhow I sold the Jeep. Now a days I store my charcoal gas in a propane tank — under vacuum…! :wink: Turns out to be easier to store the gas under vacuum than pressure… :laughing:

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#64

Explain. ???

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#65

Tom, I think you mean me…:wink: it’s my silly joke. My gasifier is made out of a propane tank and gas comes out under engine vacuum. In other words the gas is already compressed in the form of charcoal…:grin:

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#66

Oh I thought I was missing out on something new. My wife says I over think everything.TomC

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#67

Hey taitgarry00 be DOW courteous to have a simple straight name to respond to. Shows trust. That you are not baiting. Doesn’t even have to be your real name.

O.K. Retort made wood decomposition products, eh.
A woodgasifier make it’s own process heat internally from the wood input stock. As atmospheric air oxidizer it will have a lower energy produced set of gasses with the taken-in, passed trough nitrogen.
A woodgasifier intentionally thermal chemically converts as much as possible as all of the wood H’s and C’s to fuel gases of carbon monoxide, hydrogen and methane.
Multi efforts documented over 75 years that woodgasifiers will achieve min 70% to 80% wood energy conversion to combustible energy gasses efficiency.

Retort decomposition of wood requirs NO, in fact deamnds No air into the retort to be introduced.
So, yes. The moisture and tars separated out, out gases will be more energy dense not having Air/nitrogen gas dilutions.
But . . . as your article points out it could only ever convert ~15% of the dry wood weight to a heating/engine fuel grade set of gases. So only ~15% conversion efficient. This is relevant in that for the same engine shaft used power you would have to source, prep, and feed handle FIVE times as much wood!
And , , , a Retort system requires an external heat source to do the heating/decomposition.
Use the previous made and stored “fuel” gases for this for a zero outside use net then availble?
Use the previously made carbon/charcoal as the heating fuel? Might? have some high value charcoal left, maybe. Not much.
And still as 1800’s and 1900’s wood-for-chemicals plants all had: be multiple streams of by-products nasties as your article indicates, accumulating, in 21st Century all-have-camera’s time then need converting/disposing. No more 1800’s, 1900’s dump, hide, move-on allowed anymore.

Really, man. I am not trying to chritisize, or be argumentative, but just show why this once-was, has now been set aside. Too many processes complexities. Too many process downstream. downsides to deal with.

So you really are not proposing compressing storing producer made woodgas.

Regards
Steve Unruh

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#68

Hi, sorry that my member name didn’t appear, not sure how I was able to respond, no sleight intended, my name is in the email anyways, Garry Tait. I guess I’m just not too tech concerned…

I appreciate the challenging atmosphere, it seems to be a very practical minded group.

Depending on how a person values biochar, a way of making it while deriving some benefit / efficiency might factor in. It seems it also has a market value, so that could be a factor.

From the documentation, it seems the gases may be fairly equal. One big question is if the “bio oil” can be recycled and cracked, although it has value as is. I expect between the not insignificant charcoal left, (roughly 1/3 of the potential btu’s), and the tars, the energy derived from the wood is roughly equal. A retort system is not going to be as efficient a user of heat over all, due to the design, so I would expect a gasifier will probably show an over all energy efficiency perhaps 30 - 40% greater.

But… Retort fuel doesn’t need to be chunked, reducing labour and energy in processing and handling, and eliminating the need for a chunker. So a person is handling more wood, but putting significantly less work into each pound / cord. A retort can be largely barrels, with some shrouding and insulation, very simple to put together and replace in comparison, very low cost, no fans, gauges. The process can easily be scaled, processing way more wood. Keeping in mind that combustible gas is not the only valuable product if going that route.

As for pollution issues, I think they are largely the same for gasifier condensate, or a retort, phenols and water soluble tars, which should be dealt with responsibly.

A retort isn’t likely to be contaminated with oxygen, as the system is inherently self pressurized.

It seems that CO2 is much easier to scrub than nitrogen, at least at a home scale. From what I read NaOH / lime scrubbing can efficiently remove the CO2, making for a much different quality of gas. I have doubts that retort gas would be any better to compress than wood gas, unless it was scrubbed, and scrubbing seems like unreasonable effort for either low energy gas, better to look at using them as is.

As an aside, biogas methane would be a far better alternative as a high energy compressed gas, and would merit scrubbing.

I happen to have a lot of land, and a lot of wood, so a way of producing energy while improving soil fertility with minimal handling seems optimal. Gasification is hard to beat for mobile applications, but stationary is a different situation.

I expect there’s a range of opinion amongst members regarding climate change, but if a person is concerned about atmospheric CO2, there’s really no other practical way an individual can take carbon out of the atmosphere, effectively permanently, other than making charcoal, and putting it into the soil. True carbon negative living, and better soil sounds good to me.

Regards,

Garry Tait

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#69

" there’s really no other practical way an individual can take carbon out of the atmosphere, effectively permanently, other than making charcoal"

Thats a teaser for me isn’t it :wink:

Boudouard reaction, provoked with charcoal only gasifier… :stuck_out_tongue:

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#70

Hi Gary what Koen is hinting at is apart from the compressing gas angle you perfectly described a charcoal gasifier fuel prep setup. I would suggest you consider the charcoal “residue” as your compressed fuel. I would posit that a charcoal gasifier would be no heavier then a compressed gas tank. You get the carbon sequestration angle in the residue left from sizing, no tar or condensate issues, no energy loss from compression. Just some thoughts
It guides my actions anyways. It does tie you to a central hub though…
David Baillie

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#71

I wasn’t aware of the Boudouard reaction, sounds very interesting, but very technically demanding. If it can be accomplished on a small scale it could have potential. Would the aim be to synthesize methanol, or another product, or just to improve the energy of the gas?

In response to David, yes, I agree that charcoal makes a far more practical concentrated fuel source, and a charcoal gasifier should be simpler, and lighter than a full blown wood gasifier, thus their use on motorbikes in Europe in WWII. Especially where I live, where heating a house on wood could take as much as 5 cords of wood a winter, a person could easily imagine a charcoal producing gasifying stove, ample charcoal fuel for summer farming operations and maybe enough for driving. That whole process would be somewhat carbon negative, ignoring the smelting of the steel. To be environmentally sound the “waste” energy from charcoal production has to be used in some way.

The only trouble that I see is that there is no home size chunk wood, continuous charcoal producing stove out there. I see members have worked on modified pellet stoves, but I would want a chunk wood stove, at least small chunk, that can be produced with a saw.

There is a gasifying system heating a greenhouse operation in Leamington Ontario using a self developed wood chip combustion system which automatically regulates, and can be used in a biochar production mode, but the system is industrial scale.

My motivation is that I feel we have a massive challenge in order to neutralize our carbon emissions, and preserve any part of our way of life. A new automobile may embody as much as 35 metric tonnes of CO2, (imagine a tractor, or combine…) - that’s a tremendous deficit to try to balance, never mind the other aspects of our lives. To balance that out, we need some major carbon sink, tons per year, and not some fantasy version dreamed up by an oil company. Charcoal in the ground is concrete, and nobody is going to undo that.

I also feel that choices for biomass energy can be situational - if a person has ample wood, with little value, or cost in gathering, or if living in a city with less supportive neighbours, space, situation, and resources will lead to different solutions. For some things biomass methane might be more practical, especially in a livestock situation, for others ethanol from sugar beets or Jerusalem artichoke, or biodiesel from sunflowers or canola.

For this thread, I think syngas can be efficiently stored in low pressure bags, but that likely is only a practical solution for people living in a farm setting. To do better will require scrubbing nitrogen and or CO2, for diminishing returns.

Regards,

Garry Tait

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#72

I found it easy to make charcoal in my barrel stove, no grates. The down side was more ash to screen out but the heat was used. Might not work in a house because of the dust when shoveling out the charcoal from the wood. And outside wood boiler would be nice.

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#73

An outside wood boiler of some sort will be my solution I think… Someday. Right now I have a 4 year old a 2 year old a small construction company, gardens and some attempts at leisure; so the back burner is very crowded. I like the lemington example it could scale down I’m sure. I have thought a cone kiln in a boiler with an auger would be the way to use regular sized logs…
Best regards David Baillie

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#74

I have been experimenting with a 5 gallon TLUD, that system works very well at producing charcoal, but just as a batch system. They are more of a camping or third world cooking solution, or for warming a tractor off grid (probably an alien concept for many of the members, but very necessary here if things are going to start in the depths of winter…)

I agree that an outdoor boiler is the way to go, always best to keep the fire away from the house, and easier to get the wood to the fire.

Quality of charcoal is important, not all charcoal is equal, if it isn’t fired to a high enough temperature it carries tars and various chemicals, leading to different performance in a gasifier, or toxicity and varying chemical action as a soil amendment. An ideal system would continually subject feedstock to the same conditions, as in a pellet stove or downdraft gasifier.

The European downdraft boiler stoves come close, (ie Tarm), but are designed to burn all the charcoal.

Probably a conveyor chain as the Leamington boiler uses, or a cone combustor are the best approaches. There have been various continuous industrial wood processing systems for charcoal or chemicals, or both, starting with the Siemens system, but the wood has to be sized to the reactor to pass through the system.

Regards,

Garry Tait

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#75

Gary you should take a look over in the charcoal side. We’ve discussed out many of the themes you touched on. I for one know very well about warming up equipment. My next odd job is to remove my tractor’s starter which did not like my attempt to start it at -14c. It’s odd since it has started at -30. It’s been weak since I got it but its bad maintenance on my part I should have switched out for synthetic oil in the fall… I have read a lot about different grades of charcoal but honestly closed retort or open retort my tractor can’t tell the difference. Most charcoal makers are producing for cooking so are indifferent to tars. I get down right obsessive with machinery on the line. I have a large tlud made using a 100 lb propane tank as a barrel and a 55 gallon barrel as an outer shell. It’s currently sitting under 3/4 of an inch of freezing rain. The idea was to have several with a single chimney suspended above. Rotate them through, collect heat with water tubing. Another project for the back burner pile!
David Baillie

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#76

Here’s the pocket rocket boiler charcoal maker:

#77

I stand corrected regarding charcoal grades, I believe that applies to charcoal used in a barbecue. Very interesting videos on the charcoal making stove, that’s the first practical example I’ve seen. The logging video is good too. Possibly you could use a fetching arch, heavier logs can be moved, and without having to get right up to them.

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#78

Long story short, I used an arch for one season and could pull more out but it was a pain in my thight woods so turned back to an improved rear of tractor thingy. But that’s were the idea if the tree cub came from, combine the tractor with the cart so they are one and articulated.

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#79

Hi Garry,

Nothing technical demanding… is done in every gasifier…
Charcoal gasifiers are indeed the way to go, less demanding :wink:
I share your vision on the retort charcoaling-gasyfying, in more then one way…

Anyhow, to produce less Co2, we should consume less energy and use our energy spent more efficient…
burying Carbon is not the answer…
Planting three’s and use them at there full potential is far more needed… also oxygen comes from the plants :wink:
Biogas also gives a high % of Co2 , so is every fermentation process…
Using wood, cultivated for the purpose, instead of concrete, will reduce the emission of Co2 on a massive scale…
and at the final stage …
Drive on wood… with the residue’s and the end off life wood products…

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#80

Hi Koen, thanks for your positive words.

I agree entirely that the central problem of our energy troubles is wanting too much, following the wrong dream. Our energy consumption per capita is far higher than at any time in history, much of it seems to be used to produce greater prosperity for an elite, with no future vision, or significant improvement in quality of life.

I dispute a few details of some of your statements though. Sadly, using lumber for construction, as it is produced in many parts of the world isn’t a carbon sink at all. Industry standard in this country is about 2 imperial gallons of diesel per cubic meter of timber removed from the forest. Add truck transportation to a sawmill, processing, kiln drying, and further trucking to distant markets, plus all the embodied CO2 in the machinery used at the various steps and I fear dimension lumber embodies greater CO2 emissions than the lumber stores. Small scale logging will be much better. A far better alternative for housing is to use straw bales.

My understanding of bio methane is that the included CO2 is actually fairly low, around 30%. However, given that the feedstock is organic waste that would decompose anyways, there is no net increase in environmental CO2. The same applies for any other fermentation process. Where it can become questionable is with the involvement of modern agricultural products, modern agriculture being heavily dependent on fossil fuel inputs, roughly 10 calories in to one calorie of food energy out. This was the fundamental disaster of the US ethanol production. Manure, or other biomass is a different matter.

Lastly, I defend the notion of carbon in the ground, especially in poorer countries where people largely cook with wood, and where tropical soil fertility is typically very poor / fragile. The poorest 3 billion, using TLUD’s, could reverse global soot and CO2 emissions. It would also address your desire to see more trees growing.

Regards,

Garry Tait

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