A combined two-stage process of pyrolysis and catalytic cracking of municipal solid waste for the production of syngas and solid refuse-derived fuels

Abstract

Pyrolysis combined to either thermal cracking or catalytic cracking of municipal solid waste was performed in a laboratory-scale facility consisting of a fixed-bed reactor followed by a tubular cracking reactor. The results showed great potential for the production of syngas. The incorporation of inexpensive and widely available dolomite in the cracking reactor (with a constant feedstock to calcined dolomite ratio of 5:1) favoured the catalytic cracking of the primary pyrolysis products towards H₂ and CO in a temperature range of 800-900 °C. More particularly, it was possible at 900 °C to achieve a syngas consisting of more than 80 vol% CO and H₂ with a heating value of 16 MJ/Nm³. Additionally, a homogeneous solid fuel was obtained as a solid residue, which can be used to provide additional energy to support the process or as a refuse-derived fuel. Thus, the great potential of this process was demonstrated for turning municipal solid waste into a valuable gas fraction that can be used directly as a fuel or as a source of different value-added products.

Keywords: Calcined dolomite; Municipal solid waste; Pyrolysis; Refuse-derived fuel; Syngas.