Heating value characteristics of three different types of sludge i.e. domestic sewage sludge, industrials+domestic sewage sludge (thickened) showed the highest heating value (5040 kcal/kg) than order sludge types. This may be due to increased amount of organic matter presents in thickened sludge than de-watered sludge. A gradual increase in organic matter of the sludge was observed with the increase of the moisture contents. Heating value of the sludge having 60% moisture contents was found in the range between 924-1656 kcal/kg and this amount was higher than the minimum heating value (800 kcal/kg) required sustaining auto thermal combustion in sludge incineration process. Energy consumption requirement for pre-dying sludge operations revealed that the industrials sludge (de-watered) required the minimum cost (13 $/ton of sludge) to make it a sludge of fuel grade (60% W), while mixed slughe cost the highest amount for its pre-drying operations.