Resource Potential
In Hong Kong, the potential substrates for anaerobic digestion are organic
municipal solid wastes, sewage sludge and livestock wastes. The resource
available for a particular site can be estimated using following formulae.
Organic municipal solid wastes
Annual energy from anaerobic digestion of MSW (MWh)
= 
annual MSW production (tons)
X heating value of biogas generated by each ton of raw MSW (MJ/ton)
X typical thermal efficiency of biogas electricity generator (%) X
1/3600 (MWh / MJ) 
Where
 heating value of biogas generated by each ton of raw MSW = 2,258 MJ
/ ton
 typical thermal efficiency of biogas electricity generator by using
gas turbine = 35%
Sewage sludge
Annual energy from anaerobic digestion of sewage sludge (MWh)
= 
annual sewage sludge production (tons)
X heating value of biogas generated by each ton of dry solid sewage
sludge (MJ/ton)
X typical thermal efficiency of biogas electricity generator (%) X
1/3600 
Where
 heating value of biogas generated by each ton of dry solid sewage sludge
= 3,546 MJ / ton
 typical electrical conversion efficiency from landfill gas utilization
by using gas turbine = 35%
Livestock wastes
The formula is similar to the one for sewage sludge.
