[Terrapreta] energy balance and emissions

[Gary Rondeau]

Mariska,

Ron's numbers don't answer how much energy is needed to bring the fuel 
up to the exothermic point (unless it was already subtracted in the 
18MJ/kg number).   As an exercise I figured the energy required to bring 
10% H2O in the feed stock up to pyrolysis temps and it turns out to be 
about 0.35MJ.  Not sure what the heat of vaporization of the pyrolysis 
products is - but total input heat load must be in the 1-2MJ/kg range to 
get the process started. I guess theoretically you could get some of 
that back if you were directly burning the pyrolysis products and 
directly using the heat, but would probably be lost if you were 
producing bio-oil.  Another one of those annoying 10% losses!
This reference: 
http://www.dynamotive.com/assets/articles/2007/Task_34_Booklet.pdf  
claims that the pyrolysis process requires about 15% of the energy in 
the feed stock.

Gary

>Hello
>
>Sorry if this has come up before, I'm quite new on this list and haven't seen this discussed before.
>
>I'm doing some research into the benefits and draw backs of biochar production on a large scale,
>which has led me into looking at the energy use and emissions of the production process.
>
>Has anyone found any publications or other information covering this, I have pretty much exhausted the www and available literature on pyrolysis - but they are all evading this issue.
>
>I'm assuming that the energy balance of the production is positive - ie some energy will be produced in the exothermic stage which will make up for the energy used to set the process off - but I want to find some hard numbers.
>
>
>Any info is helpful
>Thanks
>Mariska
>
>  
>