Plasma gasification of sewage sludge: Process development and energy optimization

The plasma gasification process has been demonstrated in many of the most recent studies as one of the most effective and environmentally friendly methods for solid waste treatment and energy utilization. This method is applied here to the treatment of sewage sludge. Results are presented for a case study concerning the Athens’ Central Wastewater Treatment Plant, at Psittalia Island. An integrated process is proposed that includes also pre-drying of the sludge. By optimizing the process with the use of the GasifEq equilibrium model, it is demonstrated that plasma treatment of 250 ton/day sewage sludge with 68% moisture results in a net production of 2.85 MW electrical energy.