[Stoves] How to make smokeless coal?

[Nikhil Desai]

Crispin:

You say "neither a fuel nor a stove can, on their own, be ‘clean’."

Oh, get off this "clean" bandwagon. There is no quantitative measurement of
'clean' that is independent of the context.

What is "clean"? Some particular PM2.5 hourly average emission rate?

Whoever said so and on what basis? Figments of Kirk Smith's imagination do
not constitute reality. For years he did painstaking epidemiological
research and then he joined the Global Burden of Disease gang of computer
programmers. With the mumbo-jumbo of "equitoxicity" and "integrated
exposure response".

Would you believe in "equi-remedial" properties of all foods, cooked and
uncooked? Irrespective of any direct measurements of what you ate when
where?

Or that some integration of your lifetime exposure to sub-zero temperatures
puts you in a specific time-block for death? Without any direct
measurements of temperatures or your clothing, your location?

That is what the WHO nonsense about air pollution killing 7 million people
a year amounts to.

Just get over 'clean'. It is like "obscene" - a matter of prevailing
community standards.

One thing I must admire WHO et al for -- with zero evidence for
population-wide "disease impacts" of cooking by solid fuels per se, a
necessary body blow has been hit to the fetishists of "renewable" biomass.

After so many self-goals, we might finally learn how to play the game.

If we only  get out of this hypnosis by propaganda.

Nikhil


------------------------------------------------------------------------
Nikhil Desai
(India +91) 909 995 2080
*Skype: nikhildesai888*


On Tue, May 23, 2017 at 12:25 AM, Crispin Pemberton-Pigott <
crispinpigott at outlook.com> wrote:

> Dear Darpan
>
>
>
> I would like to offer an alternative to this comment:
>
>
>
> >We are talking about region specific fuel and user practise which is
> difficult to replace with smokeless dung, smokeless wood, smokeless
> diesel or even LPG. Smokeless coal is the cheapest and the most immediate
> solution to the problem.
>
>
>
> There is another much cheaper alternative which is to build stoves with
> combustion systems that do not make ‘smoke’. A smokeless stove can burn
> supposedly ‘smoky fuel’ and emit no smoke. Semi-coking coal (or wood)
> greatly increases the cost per MJ and does not guarantee anything. All
> fuels are burned in a context and the context may be inappropriate.
>
>
>
> After an examination of the matter one quickly comes to the position that
> only a combination of a certain fuel and stove emit no (or very low)
> amounts of smoke. Think of a diesel engine and diesel fuel: putting diesel
> fuel into a gasoline engine will create a great deal of smoke because it is
> not designed for that fuel. Same with stoves.
>
> >Thus 'smokeless coal'.
>
> There is no such thing as a ‘smokeless coal’. Or smokeless anything else.
> That is a marketing gimmick. Any fuel can be made to smoke.
>
> Two evidences:
>
> Testing by Guenther Baumbach
> <https://books.google.ca/books/about/Air_Quality_Control.html?hl=de&id=OCdSAAAAMAAJ&redir_esc=y>
> who literally wrote the book on air quality control and ambient particle
> measurements tested the emissions using various fuels from traditional
> Mongolian stoves in 2008, attended by Prof Tseyen-Oidov and myself. He
> showed that putting semi-coked briquettes into the unmodified stove did not
> reduce total emissions during a typical burn sequence. The emissions were
> from 0-35% greater! The reason for this is unanticipated result was that
> the semi-coked coal is much harder to light, the stove must be ignited with
> a larger mass of fuel initially (or it will not light at all), must be
> refuelled with a larger mass (or the fire goes out) and the stove must be
> refuelled earlier in the burn than with a raw coal fire (or the fire dies).
>
> Testing by Altanzul at the China Agriculture University in 2016-17 showed
> that the emissions from semi-coked fuels were consistently higher than with
> the raw coal, provided ‘the stove’ in question was designed for the raw
> coal. It is a crossdraft gasifier.
>
> These examples are evidence that the emissions from a fire cannot be
> predicted from the fuel analysis or pre-treatment alone. That said, it is
> agreed that the emissions from a PM coke fire burning in a badly designed
> stove are lower than the emissions from burning raw coal or raw wood or
> dung in a similar, badly designed stove. So what? We should compare what
> are technically appropriate alternatives.
>
> My experience of promoters of semi-coked fuel products is that they do not
> to mention emissions during ignition, or even that the ignition technique
> makes a large difference in total emissions. Unfortunately there is no
> international standard for such reporting for domestic stove performance.
> Typically, emissions are reported in terms of mass concentration for which
> there is a widely known target of 50 milligrams per cubic metre of exhaust
> gases. As the concentration of emissions in a domestic chimney is
> irrelevant to the determination of ambient air pollution (because it is a
> distributed source) the metric, selected for large emitters, has little or
> no value.
>
> Emissions from any fire are related to the completeness of combustion. If
> the raw coal is burned completely there are no PM emissions other than
> fly-ash which is a very different thing from BC + condensed hydrocarbon
> volatiles, plus it is easy to deal with. For anyone who would like test
> results demonstrating the effect of replacing a stove combustor that cannot
> burn wood or coal well with one that can, I am always happy to provide such
> data.
>
> I think the conversation about fuel composition, fuel treatment and the
> suitability of different combustion devices is very valuable, especially
> for raising awareness that neither a fuel nor a stove can, on their own, be
> ‘clean’. The appellation reflects a conceptual error that requires
> corrections before large amounts of money are spent on ‘solutions’.
>
> Regards
>
> Crispin
>
>
>
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