Well I went to the energy research laboratory yesterday to cook some oil palm fronds at 700-900 degree Celsius inside a refractory insulated carbon steel downdraft gasifier to gasify the solid biomass fuel into gas state, known as synthesis gas, mainly consists of hydrogen and carbon monoxide from incomplete combustion inside the gasifier.
So the idea is this: supply atmospheric air into the gasifier unit (the steel, silver-colored metal box you see below) via a plastic tubing from a vortex blower. There is an ongoing combustion inside the gasifier from which it consumes the supplied air but at a controlled rate so that the combustion becomes incomplete, and instead of producing carbon dioxide and water like complete combustion does, it produces mainly carbon monoxide and hydrogen.
This existence of hydrogen in the mixture ables it to be combusted as fuel either in open air or inside internal combustion engines.
So this was what we, me and a colleague named Fish, did yesterday.
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Oil palm frond or OPF was placed inside the gasifier through the top opening and then the compartment was completely sealed. Fire was initiated and the blower was turned on to push atmospheric air into the gasifier. As seen, smoke started to come out from the vertical flare point.
After some time, the smoke became thicker. The grayish smoke signified large amount of produced steam from moisture in the gasifier, best perhaps from the feedstock that was the OPF itself and from the atmospheric air due to high humidity level in the surrounding.
This smoke was actually the end product of gasification process. What you see in the images as smoke was the flammable synthesis gas. If you light the gas, it will burn beautifully.
Wires from thermocouples could be seen in the above picture for temperature monitoring and logging. And of course, me myself trying to act smart figuring out on a few things while slowly was poisoned by carbon monoxides by the seconds.
Moments before he yelled, "hearth temperature's dropping! Hearth's temperature dropping!". That means we were losing firepower inside the gasifier. Either the feedstock had all been consumed or the fire died off due to some other reasons.
And that's my baby right there ;)