Wood/Trash/Coal Gassifier product gas cooling & cleaning fluid?
Posted: Sat May 21, 2016 5:33 pm
Disclaimer: If this works well as a packaged/skid process, I'll see about selling it. I may or may not do more for anyone who contributes a good idea towards that, than a steak dinner, excellent potable or both.
So the product gas from a wood gasifier reactor needs to be above 800degC for the char surface to react with pyrolysis gas from upstream, such that H2, CH4, and CO production is maximized above lesser value fuel gasses, or CO2 which has no value.
For whatever entrained tar does not react, ash, and soot flecks which are in the gas flow, these need to be removed.
The product gas also needs to be dropped below the temperature where CO is most likely to decompose into soot and CO2 as quickly as possible.
Direct spray cooling by a fluid seems to be a good way to do this. If entrained tar, soot and ash(1) is not miscible with the fluid, then capturing that material for it being re-introduced at the process entry seems reasonably to be a matter of straining, which would be good. Alternatively a fluid which could dissolve tar and be trickled into the reactor and clean introduced in the loop, such that the dissolved crap never reaches a too high concentration, is an option.
Water is an obvious choice. I am wondering about differing oils and glycols, heavy alcohols, or appalling in some contexts as it may seem, petroleum products like fuel oil/kero/etc*.
*Should be no oxygen in the effluent gasses except briefly at startup.
Anyone have any ideas about worthwhile fluids to examine?
(1) Majority of the ash is dumped before entry to the cooler.
So the product gas from a wood gasifier reactor needs to be above 800degC for the char surface to react with pyrolysis gas from upstream, such that H2, CH4, and CO production is maximized above lesser value fuel gasses, or CO2 which has no value.
For whatever entrained tar does not react, ash, and soot flecks which are in the gas flow, these need to be removed.
The product gas also needs to be dropped below the temperature where CO is most likely to decompose into soot and CO2 as quickly as possible.
Direct spray cooling by a fluid seems to be a good way to do this. If entrained tar, soot and ash(1) is not miscible with the fluid, then capturing that material for it being re-introduced at the process entry seems reasonably to be a matter of straining, which would be good. Alternatively a fluid which could dissolve tar and be trickled into the reactor and clean introduced in the loop, such that the dissolved crap never reaches a too high concentration, is an option.
Water is an obvious choice. I am wondering about differing oils and glycols, heavy alcohols, or appalling in some contexts as it may seem, petroleum products like fuel oil/kero/etc*.
*Should be no oxygen in the effluent gasses except briefly at startup.
Anyone have any ideas about worthwhile fluids to examine?
(1) Majority of the ash is dumped before entry to the cooler.