Portable Generator

Started by flyingvan, September 15, 2013, 11:45:29 AM

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flyingvan

   If I'm reading your question correctly (producing a syngas from wood, where charcoal is a byproduct?) No, you'd make some NOx as well, and toxic water that has to be collected and disposed of as a hazardous material.  If your system works perfectly it wouldn't exhaust much CO, but the internal CO levels get extremely high---35% and up.  It takes 0.1% concentration to kill you.   
   There are a variety of gasifier systems and some trade off lower NOx emissions for a higher tar production.
   If you are gassifying charcoal, things get cleaner.  Much less of a tar problem and very low water content, so less water in the exhaust.  Even the best commercially available gasifiers recommend installing in the wide open or an open shelter because of the high CO potential.

    Bottom line, a perfectly running system at full temperature starting with a clean fuel will mostly exhaust CO2 and water
Find what you love and let it kill you.

Don_P

I would use it outside because of the potential/realities. I was mostly wondering if I was thinking through the chemical reaction correctly. Gasifying charcoal made from our sawmilling scrap at the moment, trying to crack tar from wood gas and clean it up enough for an engine is still beyond me at this point.


flyingvan

    Syngas production and use is attractive, in theory... You take any and all organic debris and produce a gas you can use to generate power.  Closed carbon cycle too so the exhaust, in the brochures at least, is less polluting.
    You only get that at a high temperature and pressure.  If CO burned readily it wouldn't need a catalytic converter with precious metals and an air pump to get it to bind with something.   You also have to figure out a way to constantly feed your system and handle the ash, tar, and dirty water.
    Large scale gasifiers are cost effective, like at wood mills.  Having a system that can stay fired up with a limitless fuel supply and constant monitoring make sense.  Smaller systems are great education tools but I haven't seen one yet that is worth the cost and effort for a single family residence.  $15,000 would buy a lot of propane.  Propane is clean, pretty safe, stores forever, energy dense.  If you're part of the climate change crowd you can sleep well knowing you are using a hydrocarbon byproduct that used to just be burned off.
    Just make sure you adjust every single propane appliance you have for altitude.  Less atmospheric pressure means a richer mix.  A richer mix means incomplete combustion, soot, dirty exhaust.  Derating things isn't just a simple formula though, and every appliance I've owned has come with a manual with a section on derating for altitude (there are some appliance manufacturers that don't bother and just disclaim not to use their product above 5,000') but in general the gas orifice size is decreased 2-4% per 1,000' above sea level.  Not linear--air is squishy so the difference between MSL and 1,000' is greater than the difference between 9,000' and 10,000'.  To further obfuscate things, some appliances make up for the altitude loss by running a richer mixture on purpose. 
    You want blue flames
Find what you love and let it kill you.

MountainDon

And just FYI in some higher altitude places, rather than derate and re-orifice natural gas appliances, the natural gas supplier devalues the natural gas. Less combustible gas energy in the natural gas volume delivered = a clean burn with the higher altitude.
Just because something has been done and has not failed, doesn't mean it is good design.

Dave Sparks

I only use Honda, always have, I know there are other good makes, I know that when a Honda fails, it is from the engine being worn out in my experience.

People tell me they got the generator at Costco and it has a Honda engine in it. They end up with problems because it is the electronics that are the hard part to do right for longevity.

I never load an engine that has not had a 3 minute warm-up and maybe longer in cold weather. Because all of my clients are charging batteries I tell them to charge the battery for the first hour without major house loads. This keeps the load steady and when they do start their house loads the battery has filled up a bit.

I hope this helps but generators are beasts and it is the reason I design my solar offgrid homes in the southwest (and places like this worldwide) to not need one. It is not inexpensive but it is very nice to not need a generator. They always fail when you need them most so I would say to have good spare. Running cooling while a wildfire is near is such a safety issue. The smoke is outside and the humans can get a break from it.

The last input is most of you guys have no way to watch the loads and how the generator is responding and so you are flying blind. Outback and Schneider power systems both have excellent portals for watching a system locally and anywhere there is internet.
"we go where the power lines don't"


Don_P

Quote from: flyingvan on March 10, 2018, 12:05:20 PM
    Syngas production and use is attractive, in theory... You take any and all organic debris and produce a gas you can use to generate power.  Closed carbon cycle too so the exhaust, in the brochures at least, is less polluting.
    You only get that at a high temperature and pressure.  If CO burned readily it wouldn't need a catalytic converter with precious metals and an air pump to get it to bind with something.   You also have to figure out a way to constantly feed your system and handle the ash, tar, and dirty water.
   

The charcoal is tar free as far as I can tell, that burned off when making the charcoal, there's the pollution. The CO seems to be lighting pretty easily as a flare. We'll see whenever I hook it to an engine. It will certainly derate the engines power. This is certainly not a quick way to make fuel but it is readily available to me at no cost. Just experimenting really, I've spent under $100 at this point.

DaveOrr

Quote from: Dave Sparks on March 10, 2018, 05:52:17 PM
I only use Honda, always have, I know there are other good makes, I know that when a Honda fails, it is from the engine being worn out in my experience.

People tell me they got the generator at Costco and it has a Honda engine in it. They end up with problems because it is the electronics that are the hard part to do right for longevity.

I never load an engine that has not had a 3 minute warm-up and maybe longer in cold weather. Because all of my clients are charging batteries I tell them to charge the battery for the first hour without major house loads. This keeps the load steady and when they do start their house loads the battery has filled up a bit.

I hope this helps but generators are beasts and it is the reason I design my solar offgrid homes in the southwest (and places like this worldwide) to not need one. It is not inexpensive but it is very nice to not need a generator. They always fail when you need them most so I would say to have good spare. Running cooling while a wildfire is near is such a safety issue. The smoke is outside and the humans can get a break from it.

The last input is most of you guys have no way to watch the loads and how the generator is responding and so you are flying blind. Outback and Schneider power systems both have excellent portals for watching a system locally and anywhere there is internet.

Would love to not need a generator but when you live in the Arctic there isn't a whole lot of solar going on in the winter. ;)
When I build my system it will be backed up with a 7KW Honda genny.  :)
Dave's Arctic Cabin: www.anglersparadise.ca

Dave Sparks

I have some folks living offgrid up there. One strategy is to have a huge array to capture the winter sun and then shut down most of it for the long days.
Yes one does need a generator up there. Beautiful place! An EU7000i is in the catbird seat with a propane mod for dual fuel.
"we go where the power lines don't"