I start drawing Saturday, may the force be with me.
You’re in Manitoba? I live in southern Ontario now, but was born and raised half my youth in Thunder Bay - maybe not too far from your neck of the woods?
The build and R&D sounds like a lot of fun. I will be looking forward to reports. I’m on the western side of the province, Brandon.
Most of the newer systems use it. It is more efficient and cuts down on emissions for coal. It was first used for coal, I think in the 40s but regained popularity in the 70s with the emissions crunch, and efficiency goals. I honestly can’t figure out exactly when it started in the coal industry. 
However, this is the first biomass plant and that was developed in 2001. they are using superheated steam. There s a lot of info on the page that is probably worth a look.
http://www.guessingrenewable.com/htcms/en/wer-was-wie-wo-wann/wie/thermische-vergasungficfb-reaktor.html
i am looking for the link for the biomass gasification that used a similar system to what I think you are talking about. I forgot the name of the company.
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I know you guys are talking about compacting the straw, but you might simply try filling a 5 gallon pail with straw and see how many pounds of the stuff you can get in it. Not much. I have a Chinese JXQ-10 that is supposed to be fed “straw chopped into 1” long pieces". I normally run it on woodchips, but I once tried running it on that kind of straw. It takes a long time to chop the straw by hand, by the way. Anyhow, a hopper full of straw is gone in just a few minutes, IIRC.
I wonder if the density-increasing physics of straw is similar to that of stacking firewood. As you split the firewood smaller and smaller, you get a more dense stack, up to a point, and then you lose density as you continue to split it smaller and smaller…
Oh- so why do they (apparently) use straw for cooking in China? I think it’s partially because that’s about all they have to burn. And, since they supposedly use it for cooking meals, maybe they only need the heat for 20 minutes at a time or so.
Pete Stanaitis
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Hi Pete,
I have to assume you are correct, straw is not going to add up to much weight per unit volume unless you pelletize it. My first shot at this is going to involve an auger continuously feeding finely milled straw up into the gasifier tube via a hopper of some kind. Picture a TLUD with a power feed of fuel from the bottom, and air delivery via the auger stem to the combustion zone. As the fuel oxidizes, gasses are produced underneath the burning bed of straw and are pulled up through it discharging out the top via suction from a fan. As the fuel burns down towards the air nozzle(s), something will trigger the auger and have it feed more fuel into the cylinder thereby pushing the burning bed back up and away from the air nozzles to repeat the burn down again. I believe this process will cycle pretty quickly due to as you say, the lack of mass to be burned, probably less than a minute between auger triggers.
Or that’s the plan anyway, I’ll find out soon enough.
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http://www.motherearthnews.com/renewable-energy/fluidized-bed-combustion-zmaz80sozraw?page=3
I have to say that I am quite impressed with what I am finding on this process. Sawdust or planer chips can be used interchangeably in smaller systems. A certain amount of sawdust could be gathered as waste in some areas, likely for the hauling. As Pete observes, the straw is low density, and hand chopping would never do. And I agree that the Chinese have probably used straw due to being so hard up, and probably using it very crudely in bundles fed into cooking fires.
The straw and chaff blown out of a combine with the straw chopper going will be nearly processed enough to use, though gathering it would require some special efforts. (Or a wagonpulled behind the combine). Way back there were cast iron hand powered straw choppers, frightening but effective small scale machines. Tub grinders handle round bales, that would do. Intermediate power and size choppers can be easily envisioned.
It feels like time to get experimenting.
Regards,
The smaller the particle size the better off you will be. It gets rid of the air in the straw but it also changes how the combustion works when you get to -really- fine material. someone on the yahoo group list explained it a long time ago, but it is really a better technology for standalone systems then mobile applications. Honestly, with a bales of straw, I might just try a big feed grinder like you would use in a hog operation. One problem is the dust itself can ignite with an open flame, but paying someone to grind up the feedstock would be a huge timesaver.
Alternatively, there is some stuff going on with pyrolization using microwaves. The two projects I am aware of one was in the EU, and the other was in Japan. The EU was trying to collect the pyrolysis oil/gas from the process, I think with algae. The japanese were trying to make carbon for battery anodes from bamboo.
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Swirl Burner. I didn’t develop it any further as sourcing the biomass became problematic.
Burns straw, small chips, etc.
Needs:
- Combustion chamber enclosure.
- Heat exchanger.
- Feed auger.
- Method to maintain fuel level.
It worked well with a hair dryer controlled by a light bulb dimmer switch.
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Thanks, I have come up with two designs. One of them used the “ash flies out” concept🙂
I’m shooting for 1/2 - 3/8" straw lengths to start with. I hope to buy an old feed hammermill with a few different screens to try out.
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You might look at a tub grinder like a roto grind. They look like they are adjustable.
If you want something a bit smaller scale, some of the leaf shedders have hammers and screens as well. Some of the cheaper ones just use a string trimmer line though.
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I had a small hammermill several years ago that worked well with cob corn, oats and other agricultural feeds. But it clogged up almost continuously on the longs from wood chip sorting and on straw. I tried every screen I had. Not positive why, but I think the blower wasn’t quite up to the job because of its small diameter. I’d be constantly removing that 180° pipe (see below) to clean it out. .
It was almost Identical to this one, but made in USA before the Chinese took over knocking off everything:
https://www.alibaba.com/product-detail/Factory-Supply-pto-small-hammer-mill_60450898518.html
Pete Stanaitis
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You’re saying the straw milled alright, but then did not make it to the blower due to weak suction and piled up in that 180 duct?
That is pretty much the type of unit I was thinking of…
Yes, the straw and the shredded wood chip “longs” would get stuck in that turn around. I thought that maybe a heftier suction device would help, but just didn’t get that far with it. Now that I think about it, I seem to remember that if I fed it REALLY slow, I could avoid that problem, but then, there goes your productivity. I had my hammermill hooked up to a cyclone of the type used to keep the dust down when transferring ground ag stuff. It was very similar to this one:
http://www.everychina.com/p-z51e5f50-97857149-home-use-crop-straw-maize-corn-rice-feed-hammer-mill-with-cyclone-and-blower.html
(But that’s a larger size hammer mill than the one I had, as you saw in my last post).
Pete Stanaitis
Well, we’ll see what pops up, I’ve seen some great deals in the past on old hammer mills, but right now there are no deals. I might have to get creative making straw particle fuel for testing if nothing worth looking at turns up 
!
We had a Gehl Model 40 hammer mill for beef cattle feed grinding about 30 years ago. I’m pretty sure that (much larger) mill would do the job. That’s a pretty old model, but new hammers are easy to make if all 4 sides of the existing ones have been used up. Of course, it was PTO powered and I think it could use up 30 HP pretty easily.
I think we paid about $50 for it in about 1980.
Good luck at your project.
Hey, do you all remember the big deal about “switch grass” back when the first Bush got into office. I wonder how they were planning to chop that stuff.
Pete Stanaitis
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I expect I’ll have to shell out between 200.00-500.00 for a decent old one, unless I buy a basket case. I have also noticed several industrial models coming up for sale. I live not far from Toronto, there are a lot of business moving, downsizing and/or closing so there is a huge amount of heavy industrial equipment coming up for sale - including the odd hammer mill. These are the best bang for the buck for what you get - but are all 600V/3PH so they need to be repowered via a gas/diesel engine.
Whatever I get will have to really be able to pound out very fine particles as I am definitely going to carry on to gasifying a vehicle if the straw gasifier works out, and that will likely mean pelletization.
I was just thinking maybe you could make pellets for pellet stoves to fund the operation. There is is a huge marker for pellets here and people will buy cheaper ones that burn faster as long as the total heating bill doesn’t cost more.
Where abouts are you? I’m near the busy metropolis of bancroft myself.
Maybe, we’ll see where it goes. I’ll bet straw pellets would be pretty ashy. I don’t have access to any wood sawdust, nor the means to transport ton after ton of it.