A waste-to-energy conversion apparatus comprising a primary combustion chamber capable of holding a load of waste, and the primary combustion chamber further comprises a heat source to heat the waste and generate a syn gas stream, grates, within the primary chamber, capable of supporting the load of waste during heating, a mixing chamber wherein the syn gas is mixed with additional combustion gas, a multi-chambered secondary combustion chamber for combusting the mixture of syn gas and additional combustion gas, and an energy extraction system for extracting the heat energy generated by the combustion of the mixture of syn gas and additional combustion gas.

A method for processing meat-and-bone meal for obtaining ashes includes steps of: feeding a catalytic fluidized bed gasifier with a meat-and-bone meal and an orthosilicate with a gas stream comprising oxygen, for obtaining a synthetic gas stream and ashes, wherein the catalytic fluidized bed gasifier is at a temperature from 400 C. to 1000 C.; grinding the obtained ashes; feeding a thermal boiler with the ground ashes, the obtained synthetic gas and a gas stream comprising oxygen for separating the ashes from the orthosilicate, wherein the thermal boiler is at a temperature from 600 C. to 2000 C.; and collecting the separated ground ashes.