[Gasification] Wood heating in the UK - whole log gasification

Doug Doug.Williams at orcon.net.nz
Sat Dec 28 17:05:47 CST 2013

Hi Gasification Colleagues,

With tongue in cheek:

I do of course include Stove, Tera Preta, Biochar enthusiasts, and lurkers from all persuasions whom I have to say (me included) are dedicated to some aspect of improving things for the masses who couldn't care less of the issues we worry about!

Where do I start however to join in this very enlightening and useful discussion, without stomping on innovative thought and sensitive aspirations? I guess I can only share my own pathetic attempts to apply all this free knowledge in a way that it would work for me, so this morning as I used the pick axe to chop up the rock like soil, thinking of the tons of mulch, horse and cow dung, chicken litter, the lime, wood ash, fertilisers,etc, applied over 30 years, I decided  to seed this bed with activated char from my gasifier to observe the difference. I'll report the results at the end of the Summer.

Being Summer holidays, I opened up the gasifier shed down the back of the block, to resume work on the waste charcoals exiting the gasifier, not specifically for any end application, but to learn more about the conditions that promote the formation of iron in a small fraction of the waste char, which are attracted to magnets. See Fluidyne Archive  www.fluidynenz.250x.com   

After spending a day sieving char from the stored chars at CalForests in June, I discovered that it is not found in great abundance just from wood gasification, and was advised to consider the bark and immediate layer under the bark as the most likely source of the iron. Gasifying bark has it's own problems apart from supply in my case, so my thoughts returned to the rapid growing coppice woods and possibly  woody stems of many invasive species. With the help of a mate doing most of the cutting up, I have coppice Poplar, and Privet hedging stems to gasify, with the hope that we can recover more than the 57g of char with iron attached from 25kg of "normal" wood blocks.

It goes without saying, that my gasifier was left as it was last used in May, full of wood that was less than dry, resulting in saturated wet char in the lower oxidation bed, all the things that I tell people to avoid for the reliable operation of a gasifier! All I could do was get it alight and let it burn up like an incinerator with the lid open, perfect to watch the boiling smoke gases full of CO, filling the shed with what the books tell us is hazardous to our health. It stirred up the rats a bit, and after a good cough myself, ran it long enough to get rid of the old fuel in order to begin the new trials. That was yesterday, so might be able to offer some follow up in a week or so.

While we should never forget the health issues of our Black Art, it comes to mind that as a wee tot, I had my afternoon naps on a pile of coal tar soaked bags piled in the cab of my fathers truck. He delivered coal, and I was as black as he most of the time! As kids we followed the traction engines towing tar tanks and watched hot tar spray onto the roads, encouraged by our mothers to stand close and get a whiff as it was good for our chests! My 1940 generation of friends are still all alive that shared this experience, so maybe this explains our interest in carbon and the gas that surrounds it becoming an addiction we just cannot ignore(:-)

More as it happens, but enjoy this time of the year as our environment allows.

Doug Williams,

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