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Practicality of wood gas electricity.

Started by Bigbo1234, October 11, 2013, 12:34:43 PM

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grweldon

Guys,

First off, from what I've read (I have zero personal experience) the gas from a gasifier can be filtered through wood chips and sawdust to remove a great deal of the tar.  As has been mentioned, a properly designed gasifier would generate gas that would contain a relatively small amount of tar and not be considered a "tar generating machine".  When I build my gasifier, I have several old engines around that I will test to determine longevity and mode of failure with the intent of improvement of the gas quality.  I believe the issue of "dirty gas" can be addressed to the point that it is a non-issue.

I don't necessesarily intend to have a mobile gas generator, but it's nice to believe that I could if I needed to.  My intended use of wood gas would be to reduce my reliance on the need for power from an external source, nothing more.  I'm not investigating wood gas as a method to save money on power, rather, how to survive relatively comfortably if/when the day should come that power isn't available.  As for steam, not to mention the issues I brought up previously, again, it doesn't seem to be practical for my purposes because  I rely on municipal water.  It's quite expensive.  Even then, if power is not available, my only water source for the moment won't be available either as pumps are required to get the water from the ground to the towers for pressure.  I could collect rainwater, but my use for that will be more important, I will treat it to make it potable (again, reliance on raw materials for treatement).

As Mad Murdock mentions, a wood gasifier would work best in a multi-generator approach using other methods of power generation in combination.  Personally, the way I would use a gasifier would be to charge (or assist in charging) a bank of batteries and using an inverter powered by those batteries to produce AC.  That would mostly overcome the on/off issues with firing and fueling a gasifier.  Batteries are still a maintenance item and force you to be dependent unless you know how to make your own.  Myself, I'm not a chemist or have any background in chemistry.  I don't know how to make hydrochloric acid and if I did, I'm sure I would have to buy raw materials... again, more dependence.

My desire is to have the ability to be self-reliant, either for a specified period of time or indefinately.  I have acres of readily available wood.  My sawmill is driven by an internal combustion engine.  My tractor is driven by an internal combustion engine.  If push comes to shove, I'll have to run them on something.  It's not practical for me to amass hundreds of gallons of liquid fuel (removing the conventional generator from my list of options as well).  Of course I'll have to have some amount of fuel on-hand for chainsaws until they break and require parts (cudos to y'all who have large chainsaw collections).

I don't consider myself a prepper, but I DO think the day will come in my lifetime (only have a couple, possibly a few decades left) where the modern conveniences we have all come to rely and depend on will disappear.

Just my take and my reasoning for exploring "producer gas".  If I were looking for a way to reduce my energy cost and assume that everything including infrastructure and economy would not change, I'd go with a grid-tied solar system since I live in Alabama and we have plenty of sun.  Obviously I'm looking at a different scenario.
My three favorite documents: The Holy Bible, The Declaration of Independence and The Constitution of the United States.

Paul_H

Quote from: Jim Timber on October 16, 2013, 11:18:24 PM
It was a general statement from my observations across numerous forums over the past few years, not directed at anyone here specifically, but at the generalizations people employ in their reasoning when trying to argue for the process.



Reading and studying is one thing but building and operating is another entirely.There was a fellow named Mark on a woodgas forum I look into occasionally and he joined up and right away began to argue for steam and even against folks like Wayne Keith who has driven across the country coast to coast a couple of times.
What struck me was this fellow had zero practical experience with either technology and yet he argued for one and against the other.He had no intention to build a steam system but was strongly urging members of the group to build.

I think of him as a Tom Sawyer,a fellow with no ambition to paint the fence himself but wanting others to do it for them.
Science isn't meant to be trusted it's to be tested

Jim Timber

Just finished a logging arch, and will be starting on my own bandsaw mill as funds allow.

Here's a little thread on the log arch:  http://www.qdma.com/forums/showthread.php?t=60228

Dealt with wood gasification briefly in HS 20+ years ago (special project for industrial tech class).  Was a helicopter tech in the army (jet engines), and have spent numerous years in automotive and medium duty truck repair.  I've also gotten a naturally aspirated wankel rotary 1.3L up to the same HP levels as it's turbo incarnation with 30lb/ft more torque and still able to idle down to 399rpm (at which point the ECU no longer thought the engine was running and would kill the spark).  But that's not really an achievement at 160HP per litre using nothing but a die grinder.   ::)

I may have just signed up here, but I wasn't born yesterday.   :)

The other option rather than gasifying the wood would be to make alcohol out of it.  Stills are pretty easy and nearly fool proof.  Carb adjustment just needs to be about twice the jet size, and be sure to change out all the gaskets from cork.

Paul_H

So if I read all about helicopters and spoke of them with authority you would be duly impressed?  :)

I read and studied about sawmilling for a few years before purchasing and operating and found that nothing beats practical experiences and that my view of milling production before hand wasn't reality.
I know a member here personally that is a steam engineer and has many more impressive achievments but he is too humble a man to list them.
Science isn't meant to be trusted it's to be tested

Jim Timber

I suppose I should've mentioned my stretch in the molecular effusion cell fabrication industry too. You might know what that is, since it's a higher form of what the gasifiers do.

I'm not here to toot my horn.  You called me out as a book worm with no practical experience, and I just told you why it's not true.

Paul_H

Impressive credentials if authenticated for sure but I don't believe I called you out on being a bookworm only but more of an armchair quarterback on woodgas and steam.
To generate the power(by steam) you want for your home one day,what volume of water and wood do you expect to use?
Science isn't meant to be trusted it's to be tested

Jim Timber

Why would I calculate the energy needs of a building which not only doesn't exist yet, but hasn't even been designed?

Driving cross country numerous times on alternate fuels is fine and dandy as well, but the hours of run time are miniscule in comparison to a 100% duty cycle application like running a building.  Engines which do well in those applications are not four stroke gasoline either, they're diesel.

Paul_H

Quote from: Jim Timber on October 17, 2013, 11:15:30 AM
Driving cross country numerous times on alternate fuels is fine and dandy as well, but the hours of run time are miniscule in comparison to a 100% duty cycle application like running a building. 

Yes,but he is thousands of mile ahead of you in knowledge and experience with woodgas so when he speaks,I tend to listen.

You read right about the diesel engines being a better choice because woodgas likes a high compression engine.
Science isn't meant to be trusted it's to be tested

grweldon

Paul, Jim,

How about let's cool it on the teat-for-tat stuff? While y'all haven't yet ceased being civil, seems as if there is potential to get there.  I would rather (maybe others would too?) talk about the subject at hand rather than debate credentials.  I see that both of you are highly qualified to comment.  Could we please remain productive?  I was enjoying the thread until it digressed...

BTW, that is a super-nice log arch Jim!
My three favorite documents: The Holy Bible, The Declaration of Independence and The Constitution of the United States.

Paul_H

Thanks for your comments but I wish you would allow me to do what I am doing.I am not hot under the collar and haven't used my credentials although I did mention two others who I respect.

Thanks for your concern but I will continue as I see fit.
Science isn't meant to be trusted it's to be tested

Jeff

I'll not be making any welcoming statements.  But I do have a few comments. First, grweldon, please don't try and moderate my fellow admins. I don't like it.


Jim Timber. I was called in to read this topic over to form an opinion on why it is heading in the direction it headed. I've determined it went south because of possibly two reasons. Both related to you. It is either your writing style, or your attitude.  Either one or both need to be adjusted to be a member here. If you would like to continue without the air of superiority, then fine.  I will always always always side with my admins on an issue, but in this case, I'm not siding with an admin. I'm siding with someone that has been there, done that, documented it for all to see against someone that thinks he knows something because he thinks he says he knows something else, comes in swaggering on a forum that 99.9% of the time is civil no matter what the discussion and causes this sort of disruption.  I don't know where you came from, or what was deemed appropriate conduct there, but here, this ain't going to fly.
Just call me the midget doctor.
Forestry Forum Founder and Chief Cook and Bottle Washer.

Commercial circle sawmill sawyer in a past life for 25yrs.
Ezekiel 22:30

Al_Smith

 :o Wow and I didn't even liven up the conversation .

Anyhoo some comments .Producer gas,char gas ,coal gas or whatever you call it was in use before wide spread distribution of natural gas .The later did not come into effect until the 30's .The first use of syn gas was around 1901 to power an automobile.

If you do a Google on the subject there is some interesting methods and pictures  such as transporting the gas in what actually is a large balloon type envelope on top of an automobile .--more --

Al_Smith

Now this boiler business .Firstly a wood "boiler" ,OWB is a water heater not a producer of pressurized steam neccessary to power a form of usable rotational power .

So that said it takes 34.5 pounds of water heated to vaporization at atmospheric pressure to produce one boiler HP or approx 34,000 BTU per HP per hour .A boiler is around 80 percent efficient so it takes about 125 percent of that .One pound of 20 percent moisture content firewood produces about 8-9,000 btu of heat .Going from heat to mechanical would be around a 90 percent
"coupling coefficient " and likewise going from mechanical to electrical with a generator would be another 10 percent lose .

You do the math on say 15 HP of steam to run around 10-12 KVA of power and look at the amount of wood it would take .

What I'm trying to point out is as they say nothing is free .You might like to be free of the power company but small scale production of electrical power you'll never beat them at their own game .

Never the less small scale production of electrical power is an interesting subject and worthy of a discussion . :)

WmFritz

   I'm sure some of you guys have heard of Ben Peterson.  I did a quick search here and came up empty. The company he started, called Victory Gasworks,  sells components for gassifiers or complete turn-key systems.  A look at the spec sheet shows it takes 2.5 pounds of biomass for 1 kWh of electricity. It also supplies hot water.  I think he has a very nice system but, pricey.


http://victorygasifier.com/
~Bill

2012 Homebuilt Bandmill
1959 Detroit built Ferguson TO35

WoodenHead

I live off grid using solar primarily, but also wind.  I have a backup diesel generator.  I looked at the GEK gasifier, a few others, and steam options.  Unless you scrounge and manage to piece together a very cheap system, the cost of the equipment is as much or more than I could buy solar panels and racking for.  I will need to replace or overhaul my diesel generator someday, so I am still toying with the idea of a gasifier.  But my best option may be to simply add more solar panels.

just_sawing

One of the ideas that I am currently working on is the fact the wood gas is compressible. This give me an avenue to produce now use later.
Here in the south it would be good to just run a generator for a few hours in the summer switching the AC on full blast and cooling down the house cool. When the unit runs out of fuel you switch back to the normal electricity. I burn slabs to get rid of them and I would live to make gas and use less electricity.
I am a firm believer in many sources with many opportunities. The gassifier isn't the end all but one of the bricks in my house that the wolf can't blow down.
You can follow me at
www.http://haneyfamilysawmill.com

Ianab

Yes, it could be compressed, like Natural gas, but the cost of the high pressure compressor needed to fit a useful amount into a cylinder is a major factor for a small system. Same issue with producing methane from Cow manure and storing that. Yes it's possible, but the cost makes it a bit impractical.

Ian
Weekend warrior, Peterson JP test pilot, Dolmar 7900 and Stihl MS310 saws and  the usual collection of power tools :)

Paul_H

Just_sawing,

Below is a quote from the FAQ's at Woodgas.net

http://www.woodgas.net/faq.html


Quote#1) Why don't you make the woodgas at home and then compress it in a tank and drive on the tank of compressed woodgas.

A) Well their are actually four reasons.

1) Woodgas is a extremely low BTU fuel it only has 150btu's per cubic foot, making it very bulky and even if you compressed it to 3600psi you would not get any driving range out of the tanks as woodgas is used in a 1:1 fuel air mixture. The range of a 100 gallon tank compressed to 3600psi would be less than two miles.

2) When you compress woodgas to extremely high pressures you are forcing the mixed gas content closer together and the free hydrogen will steal the O off of the CO sooting out the carbon and forming water. It is also speculated that the same thing slowly happens with CO under high compression. The CO will soot out a C to make CO2.

My advice would be to run your woodgasifier for a year or so and experiment a bit with gas storage and see where that leads you.I was talking about this very thing yesterday with a customer of ours at the shop.He has been very interested in our woodgas truck and has a few ideas on how it can be improved and yet he has declined a few invitations to be involved in the lighting of and driving of the truck.
I know when I was building the system there was nobody near enough for me to go visit and see a operating gasifier but if there had been an invitation from anybody within 500 miles I would have been there. Mike Larosa from WI told me to build and test first and then try new ways and he was right.
My hope is for your success and also that you would share your successes and failures freely with others that we might have progress,
Science isn't meant to be trusted it's to be tested

pineywoods

Wood gas could be used to make gasoline, ethanol, and diesel fuel. Just isn't practical to do so in small batches. I did a bit of research on this a while back. You need high pressure )4000-5000 psi and heat (450 + deg centigrade). a catalyst (iron oxide) is ineeded also. The technology is nothing new, developed by the germans in ww2 to make diesel fuel from coal. The process is quite energy intensive, and prone to runaway reactions. .
1995 Wood Mizer LT 40, Liquid cooled kawasaki,homebuilt hydraulics. Homebuilt solar dry kiln.  Woodmaster 718 planner, Kubota M4700 with homemade forks and winch, stihl  028, 029, Ms390
100k bd ft club.Charter member of The Grumpy old Men

Old Wood Whacker

You can store wood gas and compress it with a natural gas compressor. I've been talking to someone who is doing it. The compressor costs $3500 according to him. He's been grid free and makes all his fuel for his equipment and vehicles for 12 years now. I'm planning on going out to visit with him this winter. I will report on what I find when I return. It looks very promising at this point. It would be cost prohibitive for a single homestead or small mill, but he says that the way to do it is to form a local co-op and have multiple families invest in the equipment, as even a small gasifier can supply the needs of up to a half dozen homestead or small farming operations. I'm intrigued.

Stability comes from a stable fiber source. Kiln dried wood, perhaps pellets, might be beneficial. A small pellet mill isn't that expensive--about $2K. That makes the fuel cleaner and consistent, which is often the problem with wood gas. He claims that doing it this way that it is very efficient, clean and does no more harm to a gas engine than propane or nat gas. He has diesels he converted as well, but he says they still need to run on 20% diesel.

maple flats

Quote from: Ianab on November 17, 2013, 01:43:58 PM
Yes, it could be compressed, like Natural gas, but the cost of the high pressure compressor needed to fit a useful amount into a cylinder is a major factor for a small system. Same issue with producing methane from Cow manure and storing that. Yes it's possible, but the cost makes it a bit impractical.

Ian
Wow, if it's impractical, I'll have to inform the progressive farmers around here that they should quit their methane fiasco!
Impractical becomes good use of resources with education.
As for wood gas, I have saved a few sets of different plans for making a woodgas generator. May not use it until our current sources fail but I will keep the plans for "when needed". The concept intrigues me.
logging small time for years but just learning how,  2012 36 HP Mahindra tractor, 3point log arch, 8000# class excavator, lifts 2500# and sets logs on mill precisely where needed, Woodland Mills HM130Max , maple syrup a hobby that consumes my time. looking to learn blacksmithing.

beenthere

Quoteprogressive farmers around here that they should quit their methane fiasco!

If not for the Fed money funding them, it prolly wouldn't happen or continue. Good to research the concepts and find out just what works and what doesn't tho.
south central Wisconsin
It may be that my sole purpose in life is simply to serve as a warning to others

Thehardway

Have been watching this thread for a while now and I guess a few things have been eating at me.  IMHO there are a few flawed assumptions here that need to be addressed and dealt with when dealing with electrical production and off-grid use. 

First we must recognize the difference between base-load and peak loading.  If I were to design an electircal production system using either wood gasification and IC engine or a wood fired steam engine, niether of them would be running a large engine or producing power at peak demand levels.  It would be a waste of energy and resources and would make my operation inefficient, and cost prohibitive.  Very few if any of us use 18kW of power 24/7 and if we did, we should certainly look to reduce our consumption and increase the efficiency of our home/shop.

The way to do the wood gasifier power project would be to take a small, simple, but fuel efficient engine that tolerates impure fuels, is easy to repair, (few working parts) and was made to run all day long.  Something like a small 1930's era JD tractor engine.  This would be coupled to a smallish generator unit that it could drive easily while merely running at idle or low rpm.  Something on the order of a 1.5-2KW genny.  1.5-2KW plant will run anything you can plug into a 110V , 20A circuit.  This makes it a practical size.  you can use handheld power tools, microwave oven, single burner stove, small shallow well pump, etc.  You would then build some kind of storage bank for the excess power produced that was not being consumed immediately.  It could be fed back into the grid, used to charge batteries, used to pump water into an elevated reservoir to later produce power using hydro, or any other form of energy storage you could conceive.  In conjunction with this, all available energy should be taken from the process such as exhaust heat reclamation being used to heat hot water for domestic use, pre-heat for a steam production system, etc.  With low cost energy readily available in this country we have become spoiled and do not make good use of CHP potential.

The same applies for a steam driven plant.  In the world of utility scale electrical generation, the steam based power plants are optimised and operated to run at 100% capacity for base load. (Understood these are turbine engines and not piston based) Peak loading is accomplished by bringing on line small scale units in succession as demand ramps up.  Steam is not good for this.  Demand power is preferably hydro power but nowadays is more often natural gas fired reciprocating engines or turbines that spin up quickly and can quickly assume load while easily meeting emissions requirements.

Old diesel engines can in some cases be converted to run on natural gas or on a natural gas liqui fuel mix and I believe they are prime candidates for wood gas as well with some tweaking.

The idea of running these systems in a bug out scenario are purely hypothetical and I doubt it would be very successful. Without getting political,  I think whole scenario has been glorified by Hollywood and the internet and poorly thought through.  The availability of firearms is much greater than in previous times and looting and pillaging will likely limit the success of peacefully producing electrical power and living in a home unmolested, regardless of your location or power source. Unless you are heavily fortified or booby trapped your time of productivity will be short.

If you want to fool with it for fun and knowledge, it is a great hobby, otherwise, if you really anticipate and are wanting to prepare for apocalypse or total government collapse, you might be better off spending your time learning Arabic, Chinese or Russian... at least then you could beg for your life while they destroy your home and confiscate your mill and power plant?

I think for stationary power production, a low pressure steam engine/generator with heat recovery would make much more efficient use of the wood, especially if burned in a rocket stove type setup than by using a gasifier to just run an IC engine and generator.  On the other hand, mobility is much better accomplished using an IC engine and gasification than steam, primarily due to the weight of the water that must be transported for a steam based power plant.

I would like to play with a steam based system and just run it for a few hours a day doing net metering through grid tie.  I think I could produce enough in a few hours of continuous run to zero out my bill and I wouldn't have to tend it all day.  I could use thermal mass as a storage medium to provide Domestic hot water for the remainder of the day until next burn cycle which right now is my primary use of electrical energy. 
Norwood LM2000 24HP w/28' bed, Hudson Oscar 18" 32' bed, Woodmaster 718 planer,  Kubota L185D, Stihl 029, Husqvarna 550XP

Leigh Family Farm

Northman,
You bring up an interesting point in the last paragraph about running your system for a few hours at full load to offset your current power comsumption. I think this way would be a great way for someone to zero out their electric bill. I wonder how long you would have to run at full load to accomplish this? Daily? Weekly? I'm just imagining running the system for a solid 8 hours one day a week (say from 4pm - 12am on a Friday) when I am least busy. This is just me and my situational thinking so take it for a grain of salt on the rim of a margarita glass  ;)
There are no problems; only solutions we haven't found yet.

marsofold

I have considered other ways to generate electricity from wood. Looked at running a muffled pulse jet engine (no moving parts!) from wood gas. The pulsejet would have to be long, like 16 feet or more due to the low combustion velocity of carbon monoxide, and a wind turbine placed in the incoming engine wind stream to generate electricity. Or a fluidyne stirling pump engine running a small common hydro-turbine system for battery charging. There are posts on youtube with thermoacoustic and metronome stirling engines with the piston/rod being the only moving part cranking a small generator. In 1843 one of the most powerful known methods of generating electricity was an Armstrong steam generator that made high voltage power with no moving parts, an invention that got Armstrong admitted to the England's Royal Society. Such ultra-simple gadgets with little or nothing to break down appeal to me, even if not rather efficient. 

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