title: Performance analysis of RDF gasification in a two stage fluidized bed-plasma process.
abstract: The major technical problems faced by stand-alone fluidized bed gasifiers (FBG) for waste-to gas applications are intrinsically related to the composition and physical properties of waste materials, such as RDF. The high quantity of ash and volatile material in RDF can provide a decrease in thermal output, create high ash clinkering, and increase emission of tars and CO2, thus affecting the operability for clean syngas generation at industrial scale. By contrast, a two-stage process which separates primary gasification and selective tar and ash conversion would be inherently more forgiving and stable. This can be achieved with the use of a separate plasma converter, which has been successfully used in conjunction with conventional thermal treatment units, for the ability to 'polish' the producer gas by organic contaminants and collect the inorganic fraction in a molten (and inert) state. This research focused on the performance analysis of a two-stage fluid bed gasification-plasma process to transform solid waste into clean syngas. Thermodynamic assessment using the two-stage equilibrium method was carried out to determine optimum conditions for the gasification of RDF and to understand the limitations and influence of the second stage on the process performance (gas heating value, cold gas efficiency, carbon conversion efficiency), along with other parameters. Comparison with a different thermal refining stage, i.e. thermal cracking (via partial oxidation) was also performed. The analysis is supported by experimental data from a pilot plant.
authors.affiliation: Advanced Plasma Power Ltd., Swindon, Wiltshire SN3 4DE, United Kingdom; University College London, London WC1E 7JE, United Kingdom.
authors.forename: M
authors.initials: M
authors.lastname: Materazzi
authors.affiliation: University College London, London WC1E 7JE, United Kingdom. Electronic address: p.lettieri@ucl.ac.uk.
authors.forename: P
authors.initials: P
authors.lastname: Lettieri
authors.affiliation: Advanced Plasma Power Ltd., Swindon, Wiltshire SN3 4DE, United Kingdom.
authors.forename: R
authors.initials: R
authors.lastname: Taylor
authors.affiliation: Advanced Plasma Power Ltd., Swindon, Wiltshire SN3 4DE, United Kingdom. Electronic address: chris.chapman@app-uk.com.
authors.forename: C
authors.initials: C
authors.lastname: Chapman
mesh_terms: D019149:Bioreactors; D005740:Gases / Q000032:analysis*; D012037:Refuse Disposal / Q000379:methods*; D062611:Solid Waste / Q000032:analysis*; D013816:Thermodynamics
chemical_list: D005740:Gases; D062611:Solid Waste
keywords: Conversion efficiency; Fluidized bed; Gasification; Plasma; RDF