[Terrapreta] volatile matter and char

[Sean K. Barry]

Hi Dr. Michael J. Antal,

I knew you knew the answer to this question.  I have read and understood as much of your work as you have been willing to share.  We did ask about this before.  You suggested by your terse answers then, that VM% was all that mattered and that performing "proximate analysis" on a charcoal sample was all that was needed to get VM%.  When asked whether there was any way to make a determination about "what" sorts of chemicals were in a VM sample, you told us that could not be done.  Perhaps it cannot be done on a sample by sample basis.

But, by your very statement above, you clearly can tell us something about the chemical nature of what VM is.  It is not just "a measure of the weight % of material, which has the propensity to turn into and pyrolytic gases".  Today, you say ",

VM is composed of carboxylic, carboxylic anhydride, lactone, hydroquinone, phenolic, carbonylic, quinonic, ether, and pyrone functional groups attached to a carbon backbone."

How much of them respectively are there in VM from charcoal?  Are any of these more "toxic" than others in soil?  What are the toxicity levels of each in soil?  What fraction of the entire VM content from charcoal even makes it into the soil?  Do any of these chemicals react with anything in the soil other than biologicals?  Are there any methods to control, reduce, or change the chemical composition of the VM produced on or in charcoal when it is made?

There probably are proprietary methods and/or proprietary analysis?

Regards,

SKB
  ----- Original Message ----- 
  From: Michael Antal<mailto:mantal at hawaii.edu> 
  To: 'Terrapreta Preta'<mailto:terrapreta at bioenergylists.org> 
  Cc: 'Gabor Varhegyi'<mailto:varhegyi at chemres.hu> 
  Sent: Friday, December 21, 2007 7:01 PM
  Subject: Re: [Terrapreta] volatile matter and char


  There is no mystery associated with the chemical composition of volatile matter (VM).  As discussed in our publications and others, VM is composed of carboxylic, carboxylic anhydride, lactone, hydroquinone, phenolic, carbonylic, quinonic, ether, and pyrone functional groups attached to a carbon backbone.  At elevated temperatures (typically above 400 C) these groups undergo thermal cleavage and form CO2, CO, H2, H2O and CH4 and (at low temperatures) other organic compounds.  As Gerrit states below, the VM content of charcoal is largely a product of the pyrolysis process itself. 

   

  If Edward Someus were to take the trouble to read our publications, he would realize that his remarks below (concerning our work) are nonsense.

   

  Merry Christmas to all!   

   

  Michael J. Antal, Jr.

  Coral Industries Distinguished Professor of Renewable Energy Resources

  Hawaii Natural Energy Institute

  POST 109, 1680 East-West Rd.

  Honolulu, HI 96822

   

  phone: 808/956-7267

  fax: 808/956-2336

  www.hnei.hawaii.edu


------------------------------------------------------------------------------

  From: terrapreta-bounces at bioenergylists.org [mailto:terrapreta-bounces at bioenergylists.org] On Behalf Of Gerald Van Koeverden
  Sent: Friday, December 21, 2007 2:33 PM
  To: Terrapreta Preta
  Subject: Re: [Terrapreta] volatile matter and char

   

  None of our discussions seem to have got us any closer to what "VM" is....

   

  1. To what extent is VM just a concentration of pre-existing organic compounds in wood? For example, the tree has produced certain chemicals to protect its trunk from insect/diisease; are these just becoming more concentrated?

   

  2. To what extent is VM new toxic chemicals produced through the heat of pyrolysis? At what temperature are these produced? If higher temperatures are their origin, then it might well be that lesser/lower carbonized/torrified wood (the stage of cell collapse and dehydration), such as suggested by Nikolaus, might be the healthiest precursor to fertile 'char'. It could be that only the intermediate 'incomplete' carbonizing stages produce a toxic charcoal.

   

  Until we get a better handle on this VM mystery substance - its true nature, origin and decomposition - we just keep going round in circles.

   

  Gerrit

   

   

   

   

   

   

  On 21-Dec-07, at 12:54 PM, Edward Someus wrote:





        Antal makes more gasification with high burn off, resulting more alkaline ash. This is not reduce VM much but increases ash significantly, we do not want.

        True carbonization is in absence of any air, process is made in vacuum and it gas out not gasify.

        Sincerely yours: Edward Someus (environmental engineer)
        Terra Humana Clean Tech Ltd. (ISO 9001/ISO 14001)

        3R Environmental Technologies Ltd. 
        ADDRESS: H-1222 Budapest, Szechenyi 59, Hungary
        TEL handy: +(36-20) 201 7557
        TEL / FAX: +(36-1) 424 0224
        TEL SKYPE phone via computer: Edward Someus
        3R TERRACARBON: http://www.terrenum.net <http://www.terrenum.net%20/>

        3R CLEANCOAL ENERGY: http://www.nvirocleantech.com<http://www.nvirocleantech.com/>


        -------Original Message-------

        From: Gerald Van Koeverden<mailto:vnkvrdn at yahoo.ca>

        Date: 2007.12.21. 14:02:58

        To: Edward Someus<mailto:edward at terrenum.net>

        Subject: Re: [Terrapreta] volatile matter and char

        Edward,

         

        I understand that VM is not composed of naturally occurring substances, but that it itself is a product of the carbonizing process. 

         

        If this is so, then maybe the main reason for high or low VM charcoal product depends more on how much oxygen there is in the reactor to convert the VM or its building blocks into CO2? Thus the more Dr. Antal pressurizes his carbonizer with air prior to firing it, the less VM he would have in the charcoal produced in his flash reactor??

        Gerrit

         

         

         

        On 21-Dec-07, at 1:52 AM, Edward Someus wrote:

         

              SEAN

              Technical response on VM:

                a.. RE VM has an insecticidal effect 
                b.. YES, TARS ARE TOXIC FOR LIFE 
                c..   
                d.. RE Low VM% is obtained at high temperatures, basically 
                e.. NOT ONLY, NO MATTER IF YOU HAVE HIGH TEMP AND LONG RESIDENCE TIME IF THE TECHNOLOGY HEAT TRANSFER EFFICIENCY IS LOW. == ORGANICS ARE LOW HEAT CONDUCTORS. 
                f..   
                g.. RE Higher temperatures produce a more "activated" charcoal too ("activated" charcoal has a high adsorption surface area) 
                h.. NO, ACTIVATION IS AN DIFFERENT PROCESS, BY HIGHT TEMP ONLY YOU CAN NOT REACH HIGH SPECS SURFACE AREA 
                i..   
                j.. RE Now, charring biomass on a forest floor or in the soil will not likely allow such high temperatures (~1000C) to be achieved, so one wonders how the original Terra Preta soil was made with low temp char and does not suffer from toxicity. RE Perhaps any toxicity in fresh low temperature charcoal is lost over time once it is in the soil. 
                k.. TP IS NOT CHAR ONLY, IT IS A BLEND. YES, TOXICITY IS CHANGING BY TIME, AND SOONER OR LATER ADAPTED MICROBIOLOGICAL COLONIZATION MIGHT OCCUR. BUT THIS PROCESS IS HIGHLY DEPENDING ON SOIL TYPE + CLIMATE CONDITIONS AS WELL. TP ORIGINAL WAS IN TROPICAL CLIMATE WHERE ORGANIC DEGRADATION IS ALWAYS FAR MORE RAPID THAN IN CONTINENTAL CLIMATE. TP MODEN AGE DOES NOT HAVE DECADES OF TIME TO WAIT FOR ALL THIS. 

              Sincerely yours: Edward Someus (environmental engineer)
              Terra Humana Clean Tech Ltd. (ISO 9001/ISO 14001)

              3R Environmental Technologies Ltd. 
              ADDRESS: H-1222 Budapest, Szechenyi 59, Hungary
              TEL handy: +(36-20) 201 7557
              TEL / FAX: +(36-1) 424 0224
              TEL SKYPE phone via computer: Edward Someus
              3R TERRACARBON: http://www.terrenum.net <http://www.terrenum.net%20/>

              3R CLEANCOAL ENERGY: http://www.nvirocleantech.com<http://www.nvirocleantech.com/>


              -------Original Message-------

              From: Sean K. Barry<mailto:sean.barry at juno.com>

              Date: 2007.12.21. 5:43:40

              To: Terrapreta Preta<mailto:terrapreta at bioenergylists.org>; Gerald Van Koeverden<mailto:vnkvrdn at yahoo.ca>

              Subject: Re: [Terrapreta] volatile matter and char

              Hi Gerrit,

              What is the source/cause of high volatile matter in char? Does this VM (since it is 'volatile') decrease/volatize by itself over a short time? 

               

              According to the article "VM" content is "a measure of the susceptibility of charcoal to further decompose and form carbon when heated."

               

              Translation, please?? 

              We've asked Dr. Michael J. Antal this very question, when he was subscribed to the list. He was vague about what VM actually is then, too. It is measurable as the percent weight (VM%) of a charcoal sample (this is done using a "proximate analysis" test), but its chemical analysis is a mystery. Some others have recently mentioned VM has an insecticidal effect (Dr. Reddy). Edward Someus also says high VM% content on charcoal is a problem in soil. People working with Eprida, Danny Day, Dr. Christoph Steiner, etc., were wondering if the VM% was a benefit as "food for microbes".

              From what I have read about pyrolysis reactions, the VM% content is be dictated primarily by maximum internal particle temperature in the char bits (this can be somewhat related to residence time in the reactor). Low VM% is obtained at high temperatures, basically. Higher temperatures produce a more "activated" charcoal too ("activated" charcoal has a high adsorption surface area). Now, charring biomass on a forest floor or in the soil will not likely allow such high temperatures (~1000C) to be achieved, so one wonders how the original Terra Preta soil was made with low temp char and does not suffer from toxicity. Perhaps any toxicity in fresh low temperature charcoal is lost over time once it is in the soil.

              As you suggest, VM is "volatile", so I imagine it does dissipate somewhat off the surface of the charcoal, through reduction by oxygen from the air, or water. This has been recognized as a "storage" problem for fresh charcoal. Fresh charcoal can spontaneously ignite! THis occurs when the VM reacts and creates heat). Another question I had was, ... What about charcoal from natural forest fires that are quenched out by rain, for instance?. Wouldn't these be low temperature and leave toxins in the soil? But, as has been observed, soils on which forest fires have run across do not stop plant growth. In fact, there is a "bloom" of new growth. So, what's up? (with this "toxicity of of high VM% on low temperature charcoal" scare).

              I think this premise needs testing. I think no none who has provided any "field results of using charcoal in soil" here yet, has known that the charcoal they used was low VM% or even what temperature the char was made at (no data on this presented). I can make charcoal with my reactor and control the max temperature inside the reactor core. I can do a "proximate analysis" test on any charcoal produced and make measurements of VM%. I cannot discover any ways yet to characterize the chemical analysis of the VM in any way. Dr. Antal got short with me when I asked him about doing this. He told me, like in the paper, Volatile Matter is only quantifiable, not characterize-able. (Who gets to say, "That's bunk!" to a PhD?).

              It may be that the processes required to produce low VM% charcoal are more expensive than otherwise, so these producers are trying to play up the value of their product. I think the premise needs testing. I think most testing occurring now is NOT seeing this detriment in their plant growth results.

              Carry on.

              Regards,

              SKB

              ----- Original Message -----

              From: Gerald Van Koeverden<mailto:vnkvrdn at yahoo.ca>

              To: Terrapreta Preta<mailto:terrapreta at bioenergylists.org>

              Sent: Thursday, December 20, 2007 7:53 PM

              Subject: [Terrapreta] volatile matter and char

               

              G.

               

              The article is at the following link:

               

              http://www.ctahr.hawaii.edu/DeenikJ/Downloads/Tai_Charcoal_CTAHR_Sym_2007.pdf<http://www.ctahr.hawaii.edu/DeenikJ/Downloads/Tai_Charcoal_CTAHR_Sym_2007.pdf>

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