Converting Diesels to woodgas

Hi Dan,

I was typing my edit, did not see your post untill ready.

I will try to find in depth info on that engine, but it is a good candidate for woodgas, even at higher compression

Playing a little with valve timing can work wonders, a double head gasket would do the trick to bring CR down for starters.

Its the sparkplug conversion that i have to look into

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I think you might need to know the year of the motor to know if it is direct or indirect injection on those. For some reason I am thinking the last ones where direct injection but I could be wrong. Basically they have a bad rep and it is all related to the heads failing and having to be replaced.

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I read a paper somewhere that reports running on wood gas at 17:1 with no problems. Can enough diesel be introduced by aspiration with the wood gas to initiate combustion?

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Diesel would not sufficient be evaporated, but it feels as an idea to test with maybe another fuel ?
The problem is dough, to find the exact ignition point. Changing mixture requires somewhat changing ignition timing.

If you look into my last videoā€™s , i have a propane bottle that i use to mess up the engines combustion ā€¦ it sounds as some real crackers going of inside the cylindersā€¦ ( pre ignition / detonation )

IMO converting to full spark ignition is the best option.

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Sorry i missed a few post yes it is detroit deisel 1985 as your post web site noted, nice ā€™ i was thinking convert too full spark ig useing injection pump too psi switches too fire coil ? Not sure that would work with enough timeing addjustments. And fire the plugs in proper timeing.? Useing thr injector timeing.? PS i put about 120 miles this week on my old 4.3 v6 s10, on wood, she stalled on way home today, so i pulled the air intake shut, shutt off the wood gas flys, open the air supply and hit the key and on i went on i drove 2 miles left with petro.that motor is pretty much a v8 350 chevy with 2 cyclinders removed.I mean my little chevy not the deisel.Thanks for looking intoo this deisel thoughts, wish i could get too argoes, i may drive out on petro, all my vehicles are half working.

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Couple possibilities to add here.
In general I think it may make the most sense to just run a diesel on heavy oil, or maybe convert it to spark ignition for straight woodgasā€¦

BUT check out these links

https://www.chemeng.lth.se/exjobb/E487.pdf

(those two are open access, would love to get access to the full papers in these other links)

If these HCCI engines can successfully run on hot tar laden woodgas would that not be a large improvement?? In addition to getting rid of the condensers/scrubbers (past whatā€™s needed to filter particulates), seems like it could free up the gasifier design to use styles that make higher tar gas but may have other advantagesā€¦ and if youā€™re not familiar with HCCI tech, they commonly preheat the intake stream to over 100*C even when using various more conventional fuels. They are also exceptionally tolerant of very dilute/low energy fuels, while still able to run at higher efficiency than most SI engines and with enough tuning can surpass small diesels in that regard too. While producing no soot and little NOx.

If the gas remains hot all the way to the engine, wouldnā€™t a supercharger or electric blower between the gasifier and engine be able to provide the suction for safe gasification and easy woodgas:air ratio control? It could be arranged to suck air thru a throttle valve into the woodgas before the blower or a second blower could handle the engine air needs. If you were worried about tar accumulating where the cold air blends with the hot raw woodgas then just preheat the air enough to keep final mix sufficiently hot, even 160-180C may be enough once its diluted with air. Providing some boost pressure to the engine intake should offset the lower density of a warm gas mix if desired. If youā€™re worried about flashback of woodgas air mixture, which would be reasonable hahaha adding a flame arrestor shouldnā€™t be that hard, in addition to the obvious mixing the woodgas and air as close as possible to the intake.

I know a lot of this may not be so useful for folks focused on mobile applications, because from what I can tell controlling an HCCI to run right over a wide power range with transients is still quite difficult and best left to the big auto companies and those DIYers with very high level instrumentation/automation skills (and budgets)ā€¦ but if you mostly need a small unit to charge batteries, run grow lights, cogen, direct drive a heat pump, irrigate, etc it seems at least somewhat feasible.

Personally, Iā€™m contemplating what it would take to convert a 10kw ChangFa watercooled S195 into an experimental HCCI engine to play with running it on hot high tar gases. I donā€™t remember where i saw it now, but I found an abstract that stated they found no real influence of tar content on HCCI operation over their tested range of 2-16g/cubic meter and I suspect it could handle more. But thereā€™s a lot of variables involved here so who knows till they try it. I do know the mean effective pressures and cylinder pressure rise rates of all the research HCCI engines Iā€™ve read about are less than half what ole ChangFa is designed for and it would hopefully be operating at well below design RPM to make best use of low flame speed of diluted woodgas so there appears to be a bit of room for trial and error, unless Iā€™m missing something? Parts from china are cheap if it does breakā€¦ Even if its derated down to a usable shaft output of 2-3kw in HCCI mode I wouldnā€™t be disappointed, I doubt Iā€™d need more than a couple kw in the foreseeable future anyway. Still quite a few details to work out with this project tho,

And with all this talk of mods to reduce compression for a diesel to spark conversion, has anyone considered using exhaust gas recirc instead? It appears to work well to delay the autoignition in an HCCI thatā€™s sucking hot gas, seems like it would work in an SI arrangement too. AFIAK adding water spray could also accomplish a similar retarding effect, if your climate is warm enough to not freeze the lines or you plumb it to handle freezing and remelt as the engine warms up.

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Dwr (aka:) d41,
Thanks for posting these links, good info. I learned something new today! With all of this talk about biomass, it is good that people are working on IC engine technology that is outside conventional thinking. As with all new engine experiments, it starts out for heavy, stationary power plant use, then optimizes for mobile if possible. (still waiting for my nuclear-powered motorcycle). Of course, the home-built woodgas and charcoal systems are looking for build-able ways to get tar-free or low-tar fuel gas for those mobile applications. :grin:
The best we can do is a really hot hearth!

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Hello d41 and welcome to the DOW.
Thanks much for chiming in onto this topic, AND validating recommending the ChangFa S195 engines as an excellent goat-experimental that can be made into a 1st line use DYI self-fueled workhorse.
Very valid and perceptive for you to point out that what can/will be done for more predictable narrower range stationary use will probably turn into a mobile use disaster, or PITA.

Yes intake heating and EGR can be used as IC engine combustion control points. Slow, slow intentional response change characteristics. Hugely affected by ambient conditions warming up . . .on mobile altitude within less than an hour changes/rain now - sun now Spring and Fall; a sudden temperature dropping hail storm, ect.
So your intake and EGR controls can become a bit complex and maintenance nightmares to set up functional and keep year around use functional. Having to maintain these systems on factory certified engine shows well what happens when they screw up! Intake icing, cough, choke-spit, dies. To ping, ping, hole burning pistons and engine shut off runs-on.

Spark ignition has near instant on demand controllable. Easy now with off the shelf controllers to fully or semi automate for variable conditions. Eh . . so, what a periodic spark plugs wear/fouling changing out.
These considerations are why ALL of the big engine manufacturers world wide with much diesel experiences just spark convert their engines when used with gaseous fuels.

And the different intention designed multi-fueled engine by military spec are Govā€™Mint costs-plus designs never used in cost conscious civilian primary use. Surplus sourced? You will Not enjoy the keep then up and running costs at all.

Not site required, but could you at least supply a first pronounceable name, please? I have memory problems now and need name-tags to remember the good, the valid, and the relevant.
Ha! Otherwise I will think of you as ā€œBobā€. He is the most knowledgeable American S195 engine enthusiast/promoter I know of.

Regards
tree-farmer Steve unruh

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The thing is you can use a small engine-driven pump to pull a vacuum through the gasifier system and compress the new wood gas after it gets condensed, cleaned, etcā€¦, then have that somewhat compressed wood gas sent into the air intake by a carburetor/throttling deal attached to the original air intake.

Put a mod on the diesel fuel pumpā€™s throttle system to where it only throttles up to a certain amount of the way and the rest of the throttling would go to the wood gas, itā€™ll be a plug and play deal.

If the diesel is a 2 stroker, itā€™ll already have the roots blower, just attach that new mixer and throttle deal to the air intake, you could still use a small engine-driven pump to compress the gas a little bit before itā€™s sent into the intake.

Using biodiesel thatā€™s preheated to 50 degrees celsius(at most) by coolant before injection would also improve efficiency and reduce emissions further.

another thing to consider is if you wanted to, the exhaust could be recirculated back to preheat part of the air going into the gasifier before being routed into the hopper to extend mileage and regulate the temps.

http://elibrary.asabe.org/abstract.asp??JID=3&AID=32833&CID=t1984&v=27&i=2&T=1

http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.679.6356&rep=rep1&type=pdf

http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.623.9456&rep=rep1&type=pdf

https://www.researchgate.net/publication/244994762_Effect_of_Fuel_Injection_Pressure_on_Performance_and_Emission_Characteristics_of_DI-CI_Engine_Fueled_with_Chicken_Fat_Biodiesel

http://www.e-ijaet.org/media/59I11-IJAET1111165-DIESEL-ENGINE.pdf

http://web.archive.org/web/20041209031401/http://www.nf-2000.org/secure/Fair/F484.htm#final

https://onlinelibrary.wiley.com/doi/pdf/10.1002/er.4440170409

For indirect injection engines, using a piston with a dual swirling pattern, and preheating the fuel the same, could reduce smoke emissions a lot more.

There are ways to reduce nitrogen oxides in a diesel engine using low heat rejection tech too.

https://www.researchgate.net/publication/320216273_Experimental_Study_of_Effect_of_EGR_Rates_on_NOx_and_Smoke_Emission_of_LHR_Diesel_Engine_Fueled_with_Blends_of_Diesel_and_Neem_Biodiesel

I wonder how emissions would work if we did the EGR to the gasifier to recycle some of the spent heat, and turn that back into useful gases and regulate the gasifier temperature?

That would be an interesting experiment to see!

Imagine if we combined such elements of LHR with the Elsbett Engineā€™s piston tech, duothermic combustion, and injection setup? (we could still use the single pump rail system for it, just the positioning would need to be raised a little and aimed differently)

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Thanks Wes, very interesting information. I was willing to find the path to it. My generator is diesel and the actual economical en politic crisis of Venzuela is makeing a miracle to find combustibles (diesel, gasoline, gas, kerosene, ALL OF THEM!). We lose POWER from the power lines, for days. A paradox in a country with the biggest oil reserves of the planet. THANKS!

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Youā€™re welcome Abner, I canā€™t afford to get one myself or the gasifier yet, but I intend to get Wayne Keithā€™s book to see how I can implement the ideas I gave here to that system, and use it as a baseline for making an easy-to-dismantle-and-built-to-last superior take on the Imbert design.

Even though using Stainless Steels and Nitronic Alloys would be the most expensive, they would be the most effective.

I also think charcoal gasification would be great for a diesel engine too, because the exhaust would easily be reformed and broken down by the gasification process if itā€™s allowed to preheat part of the intake air before going into the gasifier, and if there are any particulates in the exhaust, they will be destroyed, nitrogen oxides will also be broken back down into nitrogen and the oxygen will help create carbon monoxide by catalytic reduction.

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Here are pictures to demonstrate what Iā€™m talking about.

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This is the part where i am interested in but also raise my eyebrows ā€¦
Where did you find that kind of wisdom because i am always on the look out for research information.

Still i have the distinct feeling that you are not fully aware, yet, about what actual gasification isā€¦ wood gas and charcoal gas, and how a gasifier really works in practical senseā€¦
Also know how about how engines are working;
For a diesel engine it needs more then just adding some gas and some valves to regulate gas flow. Timing is the most important.

gasification is never a plug and play dealā€¦ its hot on your fingers and smells on your clothesā€¦ but it puts a grin on your face when you pass the gas stationā€¦

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This article.

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I was saying ā€œplug and playā€ for lack of better wording, you have one article at the beginning of this thread to go on for diesel fuel replacement ratio, but itā€™ll be a lot of tinkering to see where your personal preference for how much power versus how long your wood gas will last you and how clean you want the emissions.

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Hi Wes,

Thanks for the link.

About emissions; donā€™t get me started there :wink:

Let me lift a tip of the curtainā€¦ i do play with carbon and gasification for a living and stripping Oā€™s from any gasses is my passionā€¦

to say it with a quote from an other, more intelligent person then me, ā€œgasification is pulling smoke thru a pile of glowing carbonā€¦ā€

I will add: 1: control your fuel, then and only then gasification becomes more easy, 2: control your charbed and youā€™l get good gasā€¦

Some will agree, some will disagree, but so is lifeā€¦

Emissions: any good gasifier will always beat the limits set for dyno fuel, in the positive sense that is, and woodgas or chargas are the only source of energy that actually are derived from airpollutionā€¦

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is it possible for a system to run wood gas, and be able to run biodiesel instead of strictly wood gas and diesel? it seems a lot of biodiesel conversion kits replace the injectors i think. not sure, just throwing that out there for a cool idea in the future.

I would say yes.
Bio-diesel might have a lower tolerance for heat and might cook-coke-polymerize in the injectors unless a significant enough amount of fuel is pass through the injector to cool the tip

https://www.dieselnet.com/tech/images/engine/fi/nozzle_deposits/~coking_deposits.jpg

If you get the correct amount of woodgas and fuel flow the injectors will stay cool enough not to coke and the combustion chamber will be cleaner with less deposits because the woodgas will help promote more complete combustion.

This probably will work with a precup diesel but technical data on it is thin and mostly suggests the DI engines work better.
The UN paid for this to be written and published.
( who would have knewā€¦ Food - woodgas - poverty reduction might be connected )

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Thanks, that is exactly what I was seeing in the explanations of the biodiesel conversion kits. It seems as if it would be difficult, but can be done. There is just so many opposing people saying that used fryer oil is the best recycling you can get, and there are the wood gas people or community like us. I like giving a middle ground and I hope more people understand both sides of the spectrum. Ever since I found Diesel engines could run wood gas I thought why not mix it up, with the WVO there is less of a power degrade. When you need more power for off roading, it would be cool to stay burning clean. Thanks again

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Never forget Tyler, some guy on the internet gave you advice ā€¦

By sayingā€¦ you mean you have tried it?
Or you heard people say they tried it?

We need people to try it and prove it.
The downfall of diesel and why it creates soot is the fuel cannot be evenly and perfectly atomized and burned.
Gasses, like wood gas promote better combustion by filling in the spaces between fuel droplets and helping them burn in a more homogeneous mix.
Well that is the theoryā€¦

Woodgas also has a lot of inert gas in it.
The benefit of this in a dual fuel engine is this willl reduce the peak temeperature inside the engine and reduce the formation of NOX.
This is why we have EGR in both gasoline and diesel engines.
Anything we can do to reduce the soot and fine particulates, reduce NOX and burn less petroleum is a step in the right direction.

Real world tests with specific fuels, engines and loads might shed more light on this.
Please post what you learn.

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