A butyl rubber bag of total volume 3.0 m3 is used as a biogas digester. Each day it is fed an input of 0.20 m3 of slurry, of which 4.0 kg is volatile solids, and a corresponding volume of digested slurry is removed. (This input corresponds roughly to the waste from 20 pigs.) Assuming that a typical reaction in the digestion process is

Question

A butyl rubber bag of total volume 3.0 m3 is used as a biogas digester. Each day it is fed an input of 0.20 m3 of slurry, of which 4.0 kg is volatile solids, and a corresponding volume of digested slurry is removed. (This input corresponds roughly to the waste from 20 pigs.) Assuming that a typical reaction in the digestion process is
C12H22O11 + H2O → 6CH4+ 6CO2
and that the reaction takes 7 days to complete, calculate 
(i) the volume of gas 
(ii) the heat obtainable by combustion of this gas for each day of operation of the 
digester
(iii) how much kerosene would have the same calorific value as one day’s biogas?