Wastewater treatment plants involve sludge production, which may pose some problems to users. These problems may be solved by conversion of sludge organic matter into high calorific value products. This technology not only eliminates sludge disposal problems but also generates fuel energy in the form of oil.
Our lab has developed a sludge liquefaction process at 200 to 300°C, at atmospheric pressure and using a solvent. The results obtained from batch and semi continuous experiments, using bitumen or various aromatic solvents are presented.
Under optimal liquefaction conditions, 40 to 60 % of the organic matter in the sludge is recovered corresponding to production of an incinerable oil with a GCV of 8500 kcal/kg.
An example of this sludge liquefaction process is envisaged for the daily treatment of 100 T of sludge.