Combined gasification and plasma treatment of waste

• Main Authors: SAEED ISMAIL, CHRIS DAVID CHAPMAN, DAVID OVENS, DAVID DEEGAN
• Format: Patent
• Language: English
• Published: 02.08.2006
• Subjects: AIR; BLASTING; CHEMISTRY; COMBUSTION APPARATUS; COMBUSTION PROCESSES; CONSUMING WASTE PRODUCTS BY COMBUSTION; CREMATION FURNACES; DESTRUCTIVE DISTILLATION OF CARBONAGEOUS MATERIALS FORPRODUCTION OF GAS, COKE, TAR, OR SIMILAR MATERIALS; DISPOSAL OF SOLID WASTE; ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR; ELECTRICITY; FUELS; HEATING; LIGHTING; LUBRICANTS; MECHANICAL ENGINEERING; METALLURGY; METHODSOR APPARATUS FOR COMBUSTION USING FLUID FUELOR SOLID FUEL SUSPENDED IN; PEAT; PERFORMING OPERATIONS; PETROLEUM, GAS OR COKE INDUSTRIES; PLASMA TECHNIQUE; PRODUCTION OF ACCELERATED ELECTRICALLY-CHARGED PARTICLES OR OFNEUTRONS; PRODUCTION OR ACCELERATION OF NEUTRAL MOLECULAR OR ATOMICBEAMS; RECLAMATION OF CONTAMINED SOIL SOIL; TECHNICAL GASES CONTAINING CARBON MONOXIDE; TRANSPORTING; WEAPONS

A waste treatment process comprises the steps of (i) gasifying waste (e.g. above 650{C) in a gasification unit to produce an offgas and a char and (ii) subjecting the offgas and char to a plasma in a plasma treatment unit (e.g. at 1100-1700{C), wherein both steps are performed in the presence of oxygen and steam. Preferably, the gasification unit and the plasma treatment unit are in fluid connection. The waste is typically municipal waste, which may be subjected to aerobic microbial digestion prior to gasification. The gas produced from the plasma treatment may be used to generate electricity. An apparatus for carrying out the process is also disclosed, which comprises a gasification unit and a plasma treatment unit, wherein both units have inlets for oxygen and steam.