[USCC] Calculating Carbon Dioxide Emissions from Composting

[David Schellinger]

Eric,
People tend to sensationalize the extent of the carbon lost during
composting, and the fact remains that whether composted and applied to
soils, applied directly to soils, or burned for energy, carbon emissions in
various forms from organic matter will probably be similar.      

Typically, organic carbon only constitutes 15% - 46% of the total mass of
organic feedstocks.  Maximum carbon lost during composting may be 50% of the
initial.  We might therefore see loss of carbon in various forms as between
approximately 7% to 25% of the initial mass.  Assuming a 35% initial organic
C concentration (say 350g/kg) and a 50% loss of carbon, only 175g/kg would
be lost as various forms of volatile carbon.  Most of the organic carbon is
converted to more stable organic complexes.  Assuming all is lost as CO2,
640g of CO2 would be lost per kg of compost.  73% of that weight would be
oxygen.     

Dave Schellinger
Phone:  (307)655-5818
 
 

-----Original Message-----
From: Eric Simenson [mailto:eric at bouldercompost.com] 
Sent: Friday, June 27, 2008 7:44 PM
To: compost at mailman.cloudnet.com
Subject: [USCC] Calculating Carbon Dioxide Emissions from Composting

  Does anyone have an equation to calculate how much carbon dioxide is 
released during composting?  I realize it depends on many factors, so 
ballpark numbers are just fine.

Thanks everyone,
Eric Simenson

Boulder Compost Co.
720-837-3286
www.bouldercompost.com