Effect of gas–slag interaction on valorisation of refuse derived fuel treated with plasma gasification

摘要

During gasification of refuse derived fuel (RDF) to produce syngas in a system in which a melt isalso produced, the gasified organic fraction of the RDF is in contact with the molten inorganicfraction, i.e. a slag. Examples of such systems are plasma gasifiers, in which crude syngas isfurther cracked in a plasma converter. Depending on the degree of gas–slag interaction, theircompositions may vary and influence the valorisation potential of both resources. To evaluate theinfluence of this interaction, a pseudo-kinetic model was developed based on localthermodynamic equilibrium between the gas phase and part of the slag phase. The interactionlevel was accounted for by varying the amount of the slag that equilibrates with the gas. Thevalorisation potential of the resulting gas and slag phases was evaluated in terms of the heat ofcombustion and the mineralogy after cooling, respectively. Engineering of the slag compositionwas made through lime-rich addition. The influence of waste composition on the gas/slagproperties and the production of a metal phase was investigated.