[Terrapreta] challenges for the future of TP

[Sean K. Barry]

Hi Lewis,

You know,  that is one of the nicest things about standards, ... there are so many to choose from.  There is a test for "proximate analysis" of charcoal, ASTM D1762.  It gives you the %moisture, $volatile matter, %ash, and %fixed carbon in a charcoal sample.  However, there is no test that determines a chemical analysis (or the repspective ratios) of the multiple different compounds potentially in "volatile matter".

Processes for pyrolysis of biomass can be monitored for things like core temperature of the gas, exit temperature of the gas (biomass/char particle temperatures are inferred), residence time of the feedstock and or charcoal, gas analysis and flow, a lambda factor (related to the stoichiometric of the 2CH2 + 2O2 => 1CO2 + 2H2O component of the pyrolysis reaction), etc.

These measurements can mostly help you control the relative yields of the pyrolysis reaction products (in mass, btu, and or volume); non-condensable fuel gases + combustion product gases + volatile matter (tars, liquids, solids) + inert gases, soot (solid carbon), heat, charcoal, and ash.  The economics of charcoal production also include feedstock material and delivery costs.  Using charcoal for soils management may require soil analysis costs, charcoal and other product delivery costs, and soil application costs.

Tying the measurable characteristics of charcoal to a "best practice" methodology for use as a soil amendment (Terra Preta style) has not been done yet.  It will likely require much field testing.  It could involve ingredients and/or mixtures with, or other than charcoal alone.
I might need to be tailored recipes, fine-tune for local soils.

Regards,

SKB
  ----- Original Message ----- 
  From: MMBTUPR at aol.com<mailto:MMBTUPR at aol.com> 
  To: michaelangelica at gmail.com<mailto:michaelangelica at gmail.com> ; terrapreta at bioenergylists.org<mailto:terrapreta at bioenergylists.org> 
  Sent: Thursday, December 13, 2007 6:08 AM
  Subject: Re: [Terrapreta] challenges for the future of TP


            from          Lewis L Smith

  Many thanks to Michael for his "stream of consciousness" comments on the NSW conference.

  The one phrase which leapt of the page at me was this >

  "The first revelation for me at the conference was this – there are massive variations, in the chemical and structural composition of char. This is the first key in understanding the need for large scale trials and research."

  This is analogous to the results of my own experience with Dr. Alexander's "energy cane/energy grass" project, with the PR cane industry, with shrimp farming and with searching the Web for gasification processes suitable for Puerto Rico. 

  The world of bioenergy is not like that of manufacturing, with its "six sigma" control concepts and specifications stated in ten-thousandth of an inch. The world of bioenergy is one of endless variation, with conditions varying from one part of a field to another, with feedstock characteristics varying from one load to another, with reactor parameters varying continually during a run and so forth. Moreover, in gasification and pyrolysis, for example, there seem to be an endless variety of configurations for the basic process and for product clean up. For example, when I last looked, there were over 250 firms in the World offering advice and/or products for biogas cleanup !

  It sounds to me that at this point, terra preta is ripe for some massive random block experiments. 

  The first task would be to sort out just what do we mean by a "variety" of terra preta and what are the significant parameters for evaluating these. Words like "agrichar", "char" and "charcoal" need to be given a meaning which can be defined by analytical methods, much as petroleum products are defined in the pre-retail markets, not by words such as "premium" and "regular", but by a list of ASTM specifications and the corresponding test methods to verify each one.

  Then we need to rank these varieties in terms of various desired incomes and then, establish a "best practice" management system for producing each of the desired varieties.  

  Cordially. ###



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