[Stoves] Effects of biomass pellet composition on the thermal and emissions performances of a TLUD cooking stove

[Anderson, Paul]

Crispin and Ron,

I will agree and disagree a little with each of you.

1.  The physical characteristics of the stove are highly important because TLUD stoves can be made in so many ways.   Therefore, the name of that specific stove is important if we are to be able to replicate or improve or comment about the stove.

2.  Does this TLUD stove make char?  If it is a TLUD stove, it DOES make char.   But the user might choose to consume the char inside the stove by continuing to cook after the pyrolytic front reaches the bottom of the batch of fuel.   If that is done, that needs to be clearly indicated in the report.   And such cooking with char is unlikely to be at the typical high power used for Chinese cooking, so is something else different?    Unanswered questions mean that a more complete report would have helped.   

3.  ... energy density >21 MJ/kg... is indeed unusual.   Expecting about 16 MJ/kg, means 5/16 = 30% increase.   Such a difference should have received a sentence or two of comment.   Now we are just guessing about possible oil content in peanut shells or some other reason.

I am glad that the research was done and that the report was published.  If Crispin knows the researcher(s) or their host institution, perhaps we might get some clarification.

Paul      (I am on my way to the US Biochar Initiative conference from Monday through Thursday.)

Doc / Dr TLUD / Paul S. Anderson, PhD
Exec. Dir. of Juntos Energy Solutions NFP
Email:  psanders at ilstu.edu       Skype:   paultlud
Phone:  Office: 309-452-7072    Mobile: 309-531-4434

> -----Original Message-----
> From: Stoves <stoves-bounces at lists.bioenergylists.org> On Behalf Of Crispin
> Pemberton-Pigott
> Sent: Saturday, August 18, 2018 10:30 PM
> To: 'Stoves (stoves at lists.bioenergylists.org)'
> <stoves at lists.bioenergylists.org>
> Subject: Re: [Stoves] Effects of biomass pellet composition on the thermal and
> emissions performances of a TLUD cooking stove
> 
> Dear Ron
> 
> Taken in order:
> 
> >I was disappointed in this article.
> 
> I am disappointed that you are disappointed. These fuels are proposed as
> substitutes for wood to the extent that are available. Very little work has been
> done investigating emissions from any small stoves. Or at all.
> 
> >1.  A TLUD with zero measurement of char production - makes no sense.
> 
> That depends on the culture. Apparently in your culture they measure char.
> Why do you think there was any char at all? The purpose of the stove is to burn
> the fuel and cook, not produce char.
> 
> >2.  Said to be a popular stove.  I find it inconceivable that users routinely do
> what is done here - count all char as waste.
> 
> They don't routinely do anything with any residual char. Who says there was
> wasted char?  Lots of people don't want char. They want cooking with as little
> fuel as possible because they have to buy it.
> 
> >The name of the stove is not given.
> 
> The name is irrelevant.
> 
> >This should be about a Tier 0 or Tier 1 stove as listed by an efficiency
> computation of about 15%.
> 
> Some people are worried about fuel efficiency, some about emission, some
> about cooking power.  In China most cooking is doing at high power. Most
> complaints about stoves are  about the lack of cooking power.
> 
> >3.  Mention is made of the importance of density - but no densities are
> provided.
> 
> I think that is an omission that could have been filled: first the density of the
> pellets, and then the bulk density.
> 
> >There is talk of pellets absorbing water easily.
> 
> That is an important observation - more important than the density. Some
> pellets do not absorb water easily.
> 
> >4.  One of the fuels (the one with the highest moisture content) is listed as
> having an energy density >21 MJ/kg;  I've never seen one that high.
> 
> So you have learned something informative about peanut shell pellets. The
> energy density is reported AD (After drying). That is indeed the energy
> content. Perhaps there is vegetable oil in it.
> 
> >5.  Figures 5 and 6 are identical - and the texts don't match with the figures.
> Maybe 6 is the one in error - but who knows?
> 
> Perhaps? The Figure label clearly states that it is supposed to be a cooking
> power chart and it shows efficiency. That is a publisher's error.  I have
> requested the correct chart so I can share it here.
> 
> >6.  Several examples of not agreeing with other authors (including Jim Jetter -
> maybe also "James"?) - but no explanations/rationales for the differences.
> 
> So what? Why should articles agree with any particular author?  The
> researchers in this case described the purpose of the experiment, the
> apparatus and the calculations used. The results are presented and discussed.
> That is how scientific results are presented.  Surely you don't expect them to
> write an agreeable conclusion first and then conduct experiments hoping to
> show it?
> 
> Apart from your correctly identifying a printer's error, I believe we can safely
> move on to the next topic.
> 
> Regards
> Crispin
>