Question

Calculate the annual carbon footprint (kg CO2eq/year) of the following processes at a rice farm:

(a) A rice processing facility that uses 100,000 kWh per year at 550 g of CO2 per kWh.

(b) 500 kg of annual methane (CH4 per year) released from rice cultivation.

(c) 50 kg of annual nitrogen oxide (N2O per year) released from composting at a rice farm.

(d) What is the total carbon footprint of processing, cultivation, and composting at this rice farm?

Answer 1

As per the IPCC second assessment report, based on 100 year global warming potential (GWP) carbon equivalent in terms of CO2 for :

1) CH4 = 21 and 2) N2O = 310 i.e. 1 kg CH4 = 21 kg CO2 and 1 kg N2O = 310 kg CO2

Total Annual carbon footprint in rice processing = 100000*550 g = 100000*0.55 Kg = 55000 kg CO2 per year

Total Annual carbon footprint in rice cultivation = 500* 21 = 10500 kg CO2 per year

Total annual carbon footprint in composting = 50*310 = 15500 kg CO2 per year

Thus total annual carbon footprint in rice farm due to all activities = 55000+10500+15500 = 81000 kg CO2 per year