Air-steam gasification of char derived from sewage sludge pyrolysis. Comparison with the gasification of sewage sludge

Gil-Lalaguna, N. ; Sánchez, J.L. (Universidad de Zaragoza) ; Murillo, M.B. (Universidad de Zaragoza) ; Ruiz, V. ; Gea, G. (Universidad de Zaragoza)

Resumen: Air-steam gasification of char derived from fast pyrolysis of sewage sludge has been experimentally evaluated in a fluidized bed as a route towards a full recovery of energy from sewage sludge. The results have been compared with those obtained from the direct gasification of sewage sludge in order to evaluate how the previous pyrolysis stage affects the subsequent gasification process. The fixed carbon content in the solid increased after the pyrolysis stage so that heterogeneous reactions of carbon with steam or CO2 assumed greater importance during char gasification than during sewage sludge gasification. Furthermore, char gasification led to an improvement in the gas yield -calculated on a dry and ash-free basis (daf)- due to the increased concentration of carbon in the organic fraction of the solid after the pyrolysis step, with an increase in the average CO yield of about 70% -in terms of g/kg solid daf-. The reduction in the fraction of carbon which forms tar is another advantage of char gasification over the direct gasification of sewage sludge, with an average decrease of about 45%. Regarding the influence of the operating conditions, the response variables were mainly controlled by the same factors in both processes.

Idioma: Inglés

DOI: 10.1016/j.fuel.2014.03.059

Año: 2014

Publicado en: FUEL 129 (2014), 147-155
ISSN: 0016-2361

Factor impacto JCR: 3.52 (2014)

Categ. JCR: ENGINEERING, CHEMICAL rank: 13 / 135 = 0.096 (2014) - Q1 - T1
Categ. JCR: ENERGY & FUELS rank: 19 / 89 = 0.213 (2014) - Q1 - T1

Financiación: info:eu-repo/grantAgreement/ES/MINECO/CTQ2010-20137

Tipo y forma: Article (PostPrint)

Área (Departamento): Tecnologías del Medio Ambiente (Departamento de Ingeniería Química y Tecnologías del Medio Ambiente)
Área (Departamento): Ingeniería Química (Departamento de Ingeniería Química y Tecnologías del Medio Ambiente)