Dear List and Chanakya, Thanks for the detailed answer. But I was thinking, shouldn't you add those two numbers because biogas both reduces Methane emissions from open pit composting AND reduces unsustainable CO2 emissions from cooking with firewood. Its not an either/or situation, right?
All the best wishes, Kyle Managing Director Schutter Energy Ltd. www.takamotobiogas.com On Nov 7, 2012, at 10:06 PM, Hoysall Chanakya wrote: Dear Kyle /Digestion List Members Answers to Kyle's Questions A rural family with 4 cattle heads producing 40kg animal dung would if completely uses it for biogas production produce @40L biogas /kg dung = 1600L biogas with 60% methane = 0.686kg methane which is 21 times more potent than co2 (21*0.686=14.4kg CO2 per day). It is assumed by attempting to put it for open pit composting only half this weight is emitted as methane = 7.2kg CO2e/day [2.63 t COe per year, per family of 5] Another approach used is that each person uses about 2kg fuelwood per capita day of which about 35% is collected unsustainably. 1 kg wood with 50% C (general assumption) produces 3.66kg CO2 or which only 35% or 1.283kg CO2 is produced per day. So in a year each person produces 0.468t CO2e and per family of 5 persons we get 2.34t CO2 equivalent per family per year. As you see both routes give roughly similar CO2e(quivalent) annually. I am sure you will get plenty of references for this. Only IPCC default will not have these specific cattle dung yield or per capita wood consumption data. This data is typical for rural India around Bangalore and has been measured many times. Best wishes Chanakya -- Dr. Hoysall Chanakya Centre for Sustainable Technologies (Assoc. Faculty at Centre for Infrastructure, Sustainable Transport and Urban Planning (CiSTUP) and Centre for Contemporary Studies) Indian Institute of Science, Bangalore 560 012 ph 91-80-2293 3046; fax-91 80 2360 0683 -- This message has been scanned for viruses and dangerous content by MailScanner, and is believed to be clean. _______________________________________________ Digestion mailing list to Send a Message to the list, use the email address [email protected] to UNSUBSCRIBE or Change your List Settings use the web page http://lists.bioenergylists.org/mailman/listinfo/digestion_lists.bioenergylists.org for more information about digestion, see Beginner's Guide to Biogas http://www.adelaide.edu.au/biogas/ and the Biogas Wiki http://biogas.wikispaces.com/
_______________________________________________ Digestion mailing list to Send a Message to the list, use the email address [email protected] to UNSUBSCRIBE or Change your List Settings use the web page http://lists.bioenergylists.org/mailman/listinfo/digestion_lists.bioenergylists.org for more information about digestion, see Beginner's Guide to Biogas http://www.adelaide.edu.au/biogas/ and the Biogas Wiki http://biogas.wikispaces.com/
