An honest critique

General Discussion
#1

So, after a lot of brainstorming, I think I’ve hung my hat on an overall scheme. I’d like your thoughts, I may have overlooked some issues or potential headaches.

  1. I am going to go with charcoal. It will be carbonized wood/straw pellets.

  2. I am going charcoal because I drive short distances most of the time, I drive in freezing weather 1/3rd+ of the year. My vehicle use is on short notice a lot of times. Visible smoke and equipment on the vehicle are not desired, and lots of driving in town will be done. Wood/straw fuel maximizes my access to feedstock. I have inconsistent availability of wood, but straw is almost free for the taking. Pelletization and making same into char ensure a reliable stream of fuel feedstock all the time.

  3. I am expecting:

a. a fast light up

b. Easy fuel storage with no spoiling, water absorption or rotting.

c. Less soot in the intake tract.

d. No fundamental need for gas cooling

e. Simple gasifier and system construction

f. Less real estate on the vehicle required

g. Less weight on the vehicle

h. Clean tar free gas 99% of the time.

I. At least 1.5 miles per lb in a 5000-6000 lb vehicle with water drip

J. No wood smoke smell on me all the time :slight_smile:

k. No vinegar / tar to drain off and dispose of.

The manufacturing of the fuel to be discussed later.

The vehicle will be the highest power to weight 4 passenger OBDI vehicle I can get, likely a big block quad cab truck or Suburban. Still weighing options.

It will also be turbocharged eventually, as I don’t see an as-is OEM option that will get me to the speeds I need to do on occasion. This can happen later after everything is up and running. I understand a seal on the compressor side back plate will be required to keep oil out of the compressor housing under the high vacuum conditions of pulling on the gasifier. I also understand that the turbo sizing should follow the requirements of an engine that is half the size of the one in use for wood-gas.

The gasification system will consist of a divorced hopper that auger feeds a sizeable reactor employing many Don Mannes innovations, and some of my own ideas. Hopper will be huge and carry enough fuel for 3000+ km (based on 18 lbs cf charcoal and 2 mpp).

No significant gas cooling will be employed other than aluminum piping feeding the gas to the front of the vehicle via the underside.

Water drip will be employed, I’ll be using a true wide band A/F monitor, some details I’m unsure of eg. should I pull gas thru the hopper to eliminate the air, or should I use a rotary airlock at reactor input?

Let me know what you think. I’ve got a ways to go before I start building the vehicle as I want to figure out a long term sustainable fuel manufacturing plan before I throw money at a char powered vehicle. Charcoal production seems to be the only real drawback of charcoal overall.

Small engine mobile fuel station
#2

Wow Will, looks like you have been doing a lot of thinking.
Without studying your post in depth it all seems reasonable except for the efficiency you mentioned. When you talk of 5 to 6000 lb vehicle with a big block engine (even with a turbo - which I haven’t seen yet with woodgas) I think 1.5 lb + per mile might be pie in the sky thinking. That is what I am getting with a 3000 lb. vehicle with a tiny engine that doesn’t like highway speeds
.[quote=“Strawman, post:1, topic:3337”]
Hopper will be huge and carry enough fuel for 3000+ km (based on 18 lbs cf charcoal and 2 mpp).
[/quote]
3000km is over 1800 miles and at 2 miles per pound that is 900 lbs of charcoal which is 5 and a half 55 gal, drums of hardwood charcoal. Not sure what straw pellet charcoal weighs. Maybe you should stick with the short trips and quick startup advantage if you go the charcoal way.
That is my honest critique for what it is worth.

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#3

I hope you meant 300 km. That´s still a long distance for a gasified vehicle.

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#4

Are you going to use this for plowing snow? Something that large and heavy gobbles gasoline, and the engine isn’t even getting up to temperature on short trips. Gasoline mileage would certainly be improved by running in the hybrid mode, and that would enable you to get up to speed.
I don’t think much of using a big hopper like that, except as a place to store charcoal. Maybe ration out what you might need for those short trips. Keep the rest of the charcoal dry. Sort of reminds me of electric cars, where one having a 2 ton battery with 300 to 500 miles of range is used for a short 25 mile round-trip to town. A smaller car with a smaller battery is more efficient, in terms of Watt-Hours per mile.
The charcoal I have been making from Oak and Mesquite hardwood is weighing in at about ten pounds per cubic foot. (vs the 18 lbs cf you mention above.) Using five gallon buckets, most of my charcoal weighs between 1.2 and 1.4 pounds per gallon. In the beginning, I would put 4 five gallon buckets of charcoal into these white bags, weigh them on a scale, and then put a tag into each bag showing the weight, date, and type of charcoal. (They typically weigh about 25 pounds.)

Mesquite_Charcoal_in_White_Bags.JPG702×1093 142 KB

Since you propose making charcoal from straw pellets, the proper sizing and screening steps can (thankfully) be eliminated. I have hundreds of bags of charcoal that still needs to be run through my charcoal grinder to make sure it is small enough (1/8" to 3/4"). There are half a dozen sealed 55 gallon barrels of dry ground and screened charcoal ready for use… a dusty dirty hobby. I do a little bit every day.
Have you looked for wood along the banks of rivers, streams, and ponds? It might be sandy and dirty, but once it is turned into charcoal, the sand and stuff is screened out. Anyhow, my two cents…

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#5

Thanks for the input Don. The hopper (divorced from the gasifier) size I was thinking of was 4’ cubed. It would hold over 1100 lbs when full. I figure if I’ve got the room, why not make it big😁! I thought I read you managed 3 mpp with your tracker? Maybe I read wrong. I seem to recall Wayne getting 1 mile per lb with the v10 driving slow. Maybe I’ll do worse, but no matter if charcoal production can be made easy, and the feed stock is cheap. I’m really only throwing numbers I considered reasonable at the plan, but if you’re only doing 1.5 mpp with the tracker, then I’d probably be lucky to do .5 mpp…

Obviously, a 6000 lb big block brick on the highway at 75 mph running a steady 7-10 lbs of boost would eat charcoal like crazy, so a big hopper would be nice. I can’t really do roadside fills out my way without attracting the wrong kind of attention. If I can do something to get at least 1500 km out of a fill, that is the safe way to go for my driving conditions.

#6

Thanks Ray, the vehicle choice is based on the requirement of carrying 4 adults in comfort, being able to do 75-80 mph minimum, carrying the entire gasification system and fuel hopper out of sight, going long distances without refuelling, and must be OBD1 for emissions purposes (1998 or older where I live).

Add that up, and I’m pretty much stuck with a full size Pickup, or a Suburban / XL Tahoe, XL Yukon.

That’s why I decided Turbocharging might be required, but there is precious little info out there on this topic. Wood gas supposedly has a very high octane number, and stoichiometric is 1:1, so a boosted engine with massive intake manifold and cylinder head ports along with 10-20 lbs of boost should yield decent results. I like the BBC because of the easy availability of rectangular port heads with massive airflow potential. The real unknown is how much dynamic range can you get out of a charcoal gasifier. I know the turndown ratio with charcoal is awesome, but what happens when going the other way? Assuming the gasifier can take the temperature, how much gas can you make by just pulling harder and harder on the unit before some unknown limit is reached? All unexplored territory.

I found that 18 lb cf number on the net, I still wonder if the density of wood pellets will translate into denser charcoal? Does oak make heavier charcoal than pine?

#7

Nope :grimacing:! Ontario is a huge Province, it’s actually more than twice the size of Sweden! Ontario is probably more than double the size of any country in the EU. Going anywhere takes hours. A lot of those hours are spent a very fast 3 lane highway at 130 + km/hr. Once you hit the Greater Toronto Area, there is nowhere to pull over, and you’re risking your life trying. It can take 2-3 hours to get from one end to the other depending on traffic.

The minute I started thinking about woodgas, I knew I had to have long range capability. I don’t mind sacrificing the entire truck bed to do it :slightly_smiling_face:! Here’s a pic of the highway in question, Nowhere safe to pull over!

#8

Look at Chris Seymour’s van build, he did a charcoal van intended for long distance trips.

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#9

Uhg! I just drove through that to get to a scan downtown. The sooner I get back to my rural rolling hills the better!
How about a removable hopper or 2 hoppers of different sizes? Not all trips are 1500km even in Ontario. Any plans on capturing heat from the char making?

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#10

I wonder where they are all going. Seems everyone want to be someplace else :smile:

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#11

Is it the same in Sweeden? 80 % of the people live in 10% of the land leaving the rest of us in a rural paradise.

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#12

Not quite, but close. About 80% in the south third of the country.

#13

Yes, I read that a while back thanks. They got some good speed with that rig too as I recall, even with that monster trailer!

#14

Ahh the joys of the 401, everyone is probably doing 10 km/hr in that pic…

As far as hopper size goes, I’m going to go as big as I can fit. If I can figure out a safe bulletproof way of feeding the gasifier from the hopper, why not? :slight_smile:

Char making experiments will start with a big TLUD, and yes I have plans, but that’ll be a different thread.

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#15

Out… :slight_smile:

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#16

They do, I know I do when I have to drive through that mess!

I’m with Dave, get me back to the rolling hills… :slight_smile:

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#17

I made pellet charcoal and it is the best fuel there is. Simple as that. Litle dust, dense and uniform. But! I might be wrong, but l think l remember straw/leaves/hulls contain lots of ash (up to 10x of wood) and ash is the enemy of any charcoal gasifier. Not so much of a problem for short trips, you can break the slag, but lets say you burn 100kg of charcoal at a time. That is 5kg of slag formed around the nozzle. Its basicly a big rock down there when it all cools.
You culd lower the temperature with egr and water injection, but that has its drawbacks…

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#18

Dave, did you ever get anywhere with the charcoal Jeep? I liked the idea of the partitioned/sealed hatch area. Probably the stealthiest way to go DOW.

#19

Well, I like the sound of that :blush:. Another member mentioned the same, and had used a TLUD to make the fuel, and it heated his shop while making the charcoal.

Thanks for bringing up the ash content, I had not considered it. You are right, wood pellets are 0.7%, straw is 7.0%. Probably the only way to work around that is to make easy access for cleaning it out like Don has done.

What is the drawback of water injection? That is what I was planing.

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#20

In my case, hardwood makes denser charcoal than pine. The 18 lb number might be from what I call “Lump Charcoal”, like what they sell for BBQ. It has some unfinished wood inside, (and usually some blue smoke) so it can impart some flavor to whatever is on the BBQ. I bought almost a ton of Ag Char from a place that bags lump charcoal for use in BBQ. It is totally useless as engine grade charcoal unless it is cooked some more. I use it in my TLUD cookstove to reduce the height of the flame, and to extend the cooking time. When making charcoal from junk wood, I have been adding 3 or 4 large coffee cans of the ag char at the very end. It emits some blue smoke, then proceeds to get converted to real charcoal.
If you pull really hard on the charcoal gasifier, the part around the nozzle turns into a real Forge, and globs of slag form. Every once in a while, you will need to dump everything out and probably rebuild or replace the nozzle(s), or at least try to remove the glass-like slag. I re-screen the dumped out charcoal to remove the fines, and lay it out on a screen in the hot sun to dry out. At one time, I was saving the slag in a bucket to show people.

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