Woodcache PBC

Woody Biomass Storage vs. Kontiki Biochar

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Statistician George Box famously stated “All models are wrong but some are useful.”  I present here a simplified (read, “wrong”) model intended to contextualize the usefulness of Woody Biomass Storage (WBS).  I hope scientists and researchers will come along and make similar models that are equally “useful” but less “wrong”.

Additionally, my mentors at Airminers have warned that we should not poop on other CDR pathways in order to improve the fortunes of our own.  Society needs ALL CDR, and the sooner the better.  My intention here is not to denigrate, and I hope readers will recognize my intention is to elevate WBS without slandering the rest of the CDR industry.

The concern I am addressing:  Some CDR registrars, buyers, and influencers consider WBS a non-durable methodology, while considering others “permanent”.  Specifically, they argue that methodologies less than 1,000 years in “durability” are not “permanent” enough.  

To combat this impression I present a simplified comparison of CDR benefits between WBS and Kontiki biochar, considered by many a “permanent” solution.  I want to show the CDR benefits of WBS is greater than that of Kontiki biochar for at least the coming 1,200 years, after which the benefits of kontiki biochar might be greater.

I’ve left out complicating factors about creation of non-CO2 ghg emissions like the generation of methane (which arguably are greater in biochar production), and ignored the need to convert stored carbon into CO2, instead focusing on commonly stored carbon in the cellular structure of wood or biochar.  I’ve balanced the preparatory processes of mastication, kiln production and final grinding on the biochar side, and excavation on the WBS side.  I’ve assumed the carbon content of the resulting biochar is about 50% and biomass destruction is about 30%.  For WBS I’ve built in wastewood decomposition rates of about .03% per year in perpetuity, which my WBS competitors and I are finding approximately true (though natural examples show that decomposition gradually slows and even stops).  I have also assumed the biochar will ultimately be used for “green” purposes like soil amendment, and that the biochar created is in fact “permanent.”  Finally, I leave out consideration of all co-benefits, like how kontiki biochar can serve as a useful soil amendment, or how not burning wood keeps particulate matter in the air low.  

Despite these simplifying assumptions (that on balance favor the efficacy of kontiki biochar in this model), we find that WBS is a more effective CDR method for more than 1,200 years.  

Why?  The biggest factor is that right upfront, kontiki biochar destroys large amounts of feedstock in a pretty harmful way–creating a giant bonfire and then dousing it with water.  This is balanced on the WBS side by the fact that it does not completely stop decomposition and emission, instead slowing them to hundredths of their natural rate.  This gradual decomposition, if not halted entirely, eventually makes WBS less effective than kontiki biochar.

What should the market conclude here?  My arguments:

  • Low emissions in the WBS production process make it more valuable than the predominant durability equations indicate.
  • Feedstock destruction and upfront emissions should be fully considered in a durability equation.
  • The Time Value of Emissions should be incorporated into durability considerations.
  • When considering all of the above, WBS is a lot more valuable for a lot longer than the market currently indicates.

We’re all in the early days here folks.  Tens of pathways are vying for attention.  WBS is probably a really effective, durable, measurable methodology, just as konitiki biochar, advanced rock weathering, and direct air capture probably are.  Like the other methodologies, the market should not shut WBS down before it has a chance to prove itself.  

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