[Stoves] Continuous gasifier for household scale - experience sharing

[Paul Olivier]

The moment one goes from batch to continuous, the process gets really
complicated. Nothing beats the simplicity of a static batch reactor.
It provides ideal gasification conditions. The problem regarding the
length of the batch cycle can be overcome if the fuel is densified. If
the reactor is filled with pellets, the length of the cycle can be
extended to well over five hours. Imagine: for a five full hours, the
operator does not have to intervene. There is no loading of rice hulls
or scrapping out of biochar during this entire period.
https://dl.dropboxusercontent.com/u/22013094/Paper/Presentations/Gasification.ppsx
The time to empty, reload and relight a batch reactor is less than one minute.
Several reactor tubes can be operated at the same time.

Thanks.
Paul Olivier


On Tue, May 14, 2013 at 8:23 AM, Tuong DoDuc
<tuong.do at devi-renewable.com> wrote:
> Dear Dr.TLUD, Paul Oliver, and others,
>
> The team in SNV Vietnam is adopting the continous gasifier model developed
> by Belonio. The manual has been obtained from the CRHET.
> Watch our first propotype: http://www.youtube.com/watch?v=xQGS-VQIj5M
> We were able to control the fire, load fuel without affecting the fire, and
> easily remove char at the bottom of the reactor.
>
> We also adopted the computer fan-casing by a cheaper, more popular fan in
> Vietnam (often used for coal and fixed wood stove). Fan costed 2USD (while
> to replicate Belonio's fan-casing, we bought the adapter for 5USD and a
> computer fan for 1.5USD)
>
> However, this is just our first step and we still have so many problems to
> fully control the fire and ease the operation.
> 1) For instance, uncontrolled moment happened when combustion occurs rigt on
> top of the fuel hopper, a lot of smoke was produced and later the fire burnt
> the fan.
> https://www.dropbox.com/s/43fkjs0axuye4oj/uncontrollable_moment.jpg
> https://www.dropbox.com/s/rd1g1cg0a9ue8qt/fan_casing.jpg
>
> 2) Another problem is that a lot of tar is produced. It deposits on pot
> bottom, burner and other part of the stove. That would also harm the user.
> An idea is to create a layer of char in the burner pipe (to filter the tar).
> Not tried yet.
>
> 3) We observes 5-10% of the gas leaked out through the char removal door. We
> burnt them, but user may not know (or they simply just don't care) that it
> is toxic.
>
> 4)  One more, it is very hard to control the final minutes of the
> gasificatoin process. It always cause inverted combustion to the fuel
> hopper.
>
> By this email, I would like to ask if some of you have done similar work
> with continuous gasifier like this to share more experience. We can thus
> reduce our time and effort in localizing this technology.
>
> Best regards,
>
> Do Duc Tuong,
>
> Renewable Energy Advisor
> SNV Vietnam
>
>
>
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-- 
Paul A. Olivier PhD
26/5 Phu Dong Thien Vuong
Dalat
Vietnam

Louisiana telephone: 1-337-447-4124 (rings Vietnam)
Mobile: 090-694-1573 (in Vietnam)
Skype address: Xpolivier
http://www.esrla.com/