[Stoves] Mercury in leafy biomass ... Was Re: Fly ash cement and of levels of radioactivity?

Tue Feb 10 16:17:14 CST 2015

Dear Paul

I knew you would be the first to express interest in this. I was aware that Hg is ubiquitous in the environment and received a less on it at the earth watching facility at Cape Point (thanks to Prof Annegarn who organised that rarely-allowed visit).

Crispin,

I inquire about the reasoning and the results related to your message.   I am supporting NONE of the statements, nor denying any of them.   Just trying to see the reasoning.

1.  Mercury (Hg) is more concentrated in leafy biomass than in woody biomass.   (Unstated about whether the Hg gets to the leaves from the air or from the soil.)

That is based on measurements of wood and leaves and pine needles. It is much higher in leaves and needles which points to a biological activity, not just ‘contamination’.

2.  Leafy biomass into briquettes is more likely to be burned in TLUD stoves than in other stoves.

I don’t know if that is true – TLUD’s can burn anything – but if they were, for example, burning ‘grass’ that is a leaf, not wood.

3.  Letting the leaves decay on the ground lets the Hg go into the ground.

No guarantee there at all. There is plenty of Hg in the ground and in the air. It is highly volatile. There is a study on the result of forest fires. Poorly burned biomass leaves char. There is very little Hg in char. That is an important point. It has a path very different from that of ash, for example, even technically it is part of ash.

4.  Burning the leafy biomass releases the Hg (95%) into the atmosphere.

That is on the low end. It is 95-99.9% released even if all the biomass is not.

5.  Is there a statement that Hg in the atmosphere is worse than Hg into the soil (and ground water)?   I leaf that to the experts to discuss.   (pun intended)

I think the assumption is that ‘if it is in the air’ it is bad for you. Cecil mentioned playing with liquid mercury. So did I. We had lots of it as my father, an engineer/industrial designer was inventing something that used it as a powerful-lift floating mechanism.

6.  Because TLUDs make char (and char does not hold back the Hg), therefore TLUDs release more Hg into the atmosphere PER UNIT OF AVAILABLE ENERGY than do stoves that do not make charcoal.

Correct. That is not stated in the articles I have read, it is however an unavoidable conclusion because where there is char, the Hg is gone. The more char there is as a fraction of the original fuel, the higher the concentration of the emissions (given any stated level of dilution) and the higher per MJ available on two counts – first because there is less energy available of the char is left behind, and second because nearly all the Hg will leave.

A first line of investigation for you and maybe Frank is to measure the remaining Hg in pyrolysis char. Maybe under certain conditions it is left behind at a ‘beneficial’ rate. But they you have two other problems: charcoal burning (touted as a use for pyro-char) and burying ‘enhanced Hg’ char in soil used for growing food while claiming that this ‘benefits food production’.  My concern is that the alarmism was probably not justified in the first place. You could call it ‘theoretical extremism’ and it joins the urban legends.  That a TLUD emits more Hg per MJ is not theoretical. That is based on measurements. The people who did it were not even aware of the concept. They just measured things.

7.  And is the above situation being declared to be important enough to be a negative aspect of TLUD stoves?

I was giving it as an example of how people can take a ‘fact’ (which it is) and turn it into ‘alarm’ and then beg for funding ‘to investigate this serious risk to human health’. You know how it goes – chase the funds.

Maybe I missed something.   

I don’t think so. Your notes are perfect. You move to the top of the class.

It is interesting that the topic of Mercury related to stoves has created so much interest for Listserv discussion, but has not been a topic at stoves meetings.   Granted that Hg is bad.   But in the grand scheme of things, are there any proposals that should be considered for implementation about Hg and biomass and stoves?

What if it turns out that people need a minimum of Hg to function properly? The fact that it is highest in leaves does not mean that it bioaccumulates for negative reasons. Maybe it is necessary for photosynthesis or something. People’s view of reality is usually over-simplified. I wouldn’t jump to conclusions.

But is someone wanted to mount an urban legend campaign ‘against TLUD’s’ picking an element of truth (pun intended) would be a good place to start. Christopher Booker <http://www.telegraph.co.uk/news/earth/environment/globalwarming/11395516/The-fiddling-with-temperature-data-is-the-biggest-science-scandal-ever.html>  is using this technique right now to attack the global temperature record, showing that it has been fiddled. The more than 22,000 comments below in only 4 days it are filled with urban legends. A great case study of fact, lie, bluster and alarm.

Because someone will, sooner or later, comment on the Hg issue and TLUD’s, you should prepare ASAP to come to the discussion with credible measurements and facts.  Because there are already forces in action recommending the combustion of leafy material as a substitute for woody biomass, the issue is not going to go away.

What we the public and promoters of stoves need to know is what the implications really are. If the mercury sector is filled with ‘agendas’ get the truth might be difficult. It would be quite proper for you to describe the matter in your book and say that basically nothing is known about the matter and it requires investigation.  You don’t have to ‘confess’ or ‘warn’ or ‘raise alarm’.  Just the facts. Minamata Disease was not caused by coal, or tuna or leaves.

Regards

Crispin

Doc  /  Dr TLUD  /  Prof. Paul S. Anderson, PhD  
Email:  psanders at ilstu.edu <mailto:psanders at ilstu.edu>    
Skype: paultlud      Phone: +1-309-452-7072
Website:  www.drtlud.com <http://www.drtlud.com> 

On 2/10/2015 2:45 PM, Crispin Pemberton-Pigott wrote:

Dear Biomass burners

There is a good article from sensible researchers  here

http://www.mindfully.org/Air/Mercury-Smoke-Biomass.htm

Now consider this and see how it affects your understanding of mercury in the environment (it is literally everywhere so pay attention).

Mercury is released disproportionally from biomass relative to the mass percent burned. In other words, operating a TLUD gasifier releases the mercury in largely gaseous form (95%) and the rest in particulate form. It is easily evaporated going from Hg+2 to Hgo. 

So should we worry about TLUD’s releasing, proportionally, about double the amount of Hg per useful MegaJoule of heat?

Hg is concentrated in the leaves, especially deciduous tree leaves. There are being processed into briquettes on an increasing scale. Basically all the Hg is released when they are burned even if there is char powder in the ash at the end.  Should we worry Richard and his alternative fuels promotion?

The most ‘toxic, mercury laden’ smoke in the stove community would come from a TLUD burning leaves from a deciduous tree while making biochar: full release, maximum concentration, least dilution during combustion.

Is everyone automatically alarmed? But TLUD’s and gasification and biochar and burning non-woody biomass are four of the darlings of the improved stove community. What now?

The answer is obviously to calculate what the emission rates are and the exposure level and the effect of such exposure before jumping to any conclusions about wood or leaves or coal or anything else.  Data matters. Coal is just old wood.  

Burn hot, maintain a cool head.

Crispin

++++++

One sandwich a week?

Who told you that?

Good grief. There is lots of mercury in the environment including in sea air, and there are completely unknown biological pathways metabolising it as was shown by the atmospheric research station at Cape Point. The general idea is that mercury is well "mixed in the atmosphere". Not so. Sometimes it drops to zero in the air blowing from Antarctica for hours at a time. There is no known process that can do this. Most atmospheric mercury is from the sea. 

I am amazed that these coal memes survive for so long. There is a really good lab at Clarkson Univ in Potsdam‎ NY that researches Hg in fish in the Great Lakes. Fantastically small quantities can be detected. One sandwich a week?  

Argh

Crispin 

Frans and Crispin,

Thanks for putting dimensions on the issue. I know that coal ash is the bad actor. 

I'm still perturbed that I can only eat one tuna fish sandwich a week because of the Mercury from coal. 

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