Gasifier Wood Gas Output Fed into a Rocket Mass Heater Core - Podcast 98

Hi Everyone,

After listening to podcast 98 and also I have been thinking along these lines over the past couple of weeks I had an idea. I have never built a working proto type of a wood gasifier or a rocket mass heater yet but I do have some basic understanding on how they work. A down draft/imbert style gasifier needs to have some form of suction or vacuum to draw the generated wood gas through the system. Currently most gasifier designs use a blower motor to start the process and then after everything is going they hand off the suction to an Internal Combustion Engine on a vehicle or generator and shut off the blower motor. Would it be possible to use a blower motor to start a gasifier going and then when it is heated up hand off the wood gas to be burnt in the core of a rocket mass heater using the draw of the rocket mass heater to provide suction. This would mean the rocket mass heater would burn the wood gas instead of the wood directly. The exhaust heat could be still be used to heat a mass and also possibly some type of non pressurized water heater storage tank. The gas could also be valved and split off to a small generator to charge batteries to run an inverter for electricity storage. Any way just wondering what everyone thought and if it would be possible.

Thank you,

This looks to me a very interesting project.

I am looking into 'biochar' to fertilize and put carbon back into the soil.

I have just joined this forum after finding a project by Dale Hodgins about building cob heater link: https://permies.com/t/10037/green-building/Building-RMH-long-before-house.

I have a fantasy of heating a community building/hostel with a big cob/rocket heater and incorptrating a biochar retort in the structure but outside the occupied envelope of the building.

Has anybody else done anything like this?

Dale how has this great project progressed?

Richard J

Richard Jannaway wrote:This looks to me a very interesting project.

I am looking into 'biochar' to fertilize and put carbon back into the soil.

I have just joined this forum after finding a project by Dale Hodgins about building cob heater link: https://permies.com/t/10037/green-building/Building-RMH-long-before-house.

I have a fantasy of heating a community building/hostel with a big cob/rocket heater and incorptrating a biochar retort in the structure but outside the occupied envelope of the building.

Has anybody else done anything like this?

Dale how has this great project progressed?

Richard J

Welcome Richard --- I'm still in the material gathering, money for other things gathering phase. I just stumbled upon this. To reach any individual here it's best to go to your topic of interest and comment there since I doubt that anyone reads all of it. Or you can go to personal messages when appropriate.

Jerol DeMars wrote:Hi Everyone,

After listening to podcast 98 and also I have been thinking along these lines over the past couple of weeks I had an idea. I have never built a working proto type of a wood gasifier or a rocket mass heater yet but I do have some basic understanding on how they work. A down draft/imbert style gasifier needs to have some form of suction or vacuum to draw the generated wood gas through the system. Currently most gasifier designs use a blower motor to start the process and then after everything is going they hand off the suction to an Internal Combustion Engine on a vehicle or generator and shut off the blower motor. Would it be possible to use a blower motor to start a gasifier going and then when it is heated up hand off the wood gas to be burnt in the core of a rocket mass heater using the draw of the rocket mass heater to provide suction. This would mean the rocket mass heater would burn the wood gas instead of the wood directly. The exhaust heat could be still be used to heat a mass and also possibly some type of non pressurized water heater storage tank. The gas could also be valved and split off to a small generator to charge batteries to run an inverter for electricity storage. Any way just wondering what everyone thought and if it would be possible.

Thank you,

why would you do this? I dont see an up side to useing the gass as the cumbustion material as nessisary. the RMH is plenty hot enough to boil water and make steam.

I was wondering what would be the point too. A gasifier is going to lose some of the heat you would otherwise have had in the RMH. Gasifiers were used in Norway and Sweden during WW2 to run engines as they had nothing else. It was inefficient, but better than nothing. In a RMH as I understand it, wood burns in a gas phase, and from what I've seen, all solid fuels must burn in a gas phase in whatever stove since for it to burn, the temperature is so high. Just depends which gas you are looking at.

To generate electricity, a Peltier heat pump could be used, and has no moving parts, alternatively a solar panel. Either would be more reliable and less maintenance than an engine driven generator. Less noise too.

Steve Harris talks about Bio fuels and corrects Jack on the difference between a rocket stove and a wood gasifier, interesting listen if the subject interests you.

http://www.thesurvivalpodcast.com/episode-707-steven-harris-on-bio-fuels-for-personal-energy-indepencence

Ernie Wisner wrote:why would you do this? I dont see an up side to useing the gass as the cumbustion material as nessisary. the RMH is plenty hot enough to boil water and make steam.

When I was designing a rocket stove sauna, I had this same thought. The constraints of the project made it an attractive proposition at the time though due to the complexities of design, I decided to play it straight.. The rocket stove sauna posed enough experimental questions NOT to add more.

The sauna is based on the Amerind sweat lodge, with the heat source in the center of the structure and total darkness inside. It seemed like a good way to place and feed the fuel at the outside of the structure and have the heat (the lions share of it anyway) on the inside. It was a way to solve for a burn tunnel of around 5 feet long with a heat riser at 3 feet tall. My thought was that I would build a TLUD looking feed (outside) and pipe the wood gas to a heat riser in the center of the building. I thought (hoped) it was possible to build a small fire under the heat riser to start the draft, then go outside and light the TLUD. "course, I wanted to do it all without blowers or moving parts..

I've no idea if it would have ACTUALLY worked.. It never left the sketch pad..
I'd still like to see it tried though, mainly out of curiosity.

would be cool to see but i cant think of what good it would do. i do like things that push the boundaries. You know i really try to make the RMH dependable so I tend to take the time to test things over time.