abstract
In this work, the concept of biomass direct (air) gasification was demonstrated in a pilot-scale bubbling fluidized bed and the influence of in-situ application of low-cost catalytic materials on the produced gas characteristics and gasifier performance was analyzed. Three different low-cost catalysts were tested: bottom bed ashes resulting from combustion of residual forest biomass derived from eucalyptus, char particles resulting from wood pellets direct (air) gasification, and synthetic fayalite (Fe2SiO4). Without using catalysts, the produced gas composition was 7.7-16.9%v CO, 3.2-8.3%v H-2, 0.5-3.4%v CH4 and 9.5 -14.6%v CO2, with 2.4-4.3 MJ/Nm(3) lower heating value, specific dry gas production between 1.0 and 1.8 Nm(3) dry gas/kg biomass (dry basis), cold gas efficiency between 13.7 and 30.5% and carbon conversion efficiency between 30.7 and 50.9%. With the use of catalysts, the produced gas composition was 14.2 -37.6%v CO, 9.5-14.7%v H-2, 2.6-3.5%v CH4 and 3.6-14.8%v CO2, with 3.9-6.3 MJ/Nm(3) lower heating value, specific dry gas production between 1.4 and 2.0 Nm3 dry gas/kg biomass (dry basis), cold gas efficiency between 38.1 and 66.3% and carbon conversion efficiency between 56.8 and 86.6%. The highest increase in H-2 concentration (352% increase) was observed on experiments using wood pellets char as catalyst while the highest increase in CO (305% increase), lower heating value (123% increase), specific dry gas production (62% increase), cold gas efficiency (262% increase) and carbon conversion efficiency (174% increase), was observed on experiments using synthetic Fe2SiO4 as catalyst. (C) 2018 Elsevier Ltd. All rights reserved.
keywords
BUBBLING FLUIDIZED-BED; MISCANTHUS X GIGANTEUS; TAR ELIMINATION; ENERGY; AIR; TECHNOLOGY; GENERATION; REDUCTION; PYROLYSIS; HYDROGEN
subject category
Thermodynamics; Energy & Fuels
authors
Pio, DT; Tarelho, LAC; Pinto, RG; Matos, MAA; Frade, JR; Yaremchenko, A; Mishra, GS; Pinto, PCR
our authors
Aleksey Yaremchenko
Principal Researcher
Gopal Shankar Mishra
Post-Doc Fellowship
Jorge Ribeiro Frade
Full professoracknowledgements
The authors acknowledge the Portuguese Foundation for Science and Technology for the financial support provided through project PTDC/AAC-AMB/116568/2010 (FCOMP-01-0124-FEDER-019346) -BiomAshTech -Ash impacts during thermo-chemical conversion of biomass, project PTDC/CTM-ENE/2942/2014 -LEANCOMB -Cellular oxide catalysts for emission lean combustion in porous media, project PO Centro 2020 (ref. CENTRO-01-0145FEDER-000005) -SusPhotoSolutions -Solucoes Fotovoltaicas Sustentaveis, and project UID/AMB/50017/2013 (CESAM) through national funds, and the co-funding by the FEDER, within the PT2020 Partnership Agreement and Compete 2020. The authors also acknowledge the Portuguese Foundation for Science and Technology and The Navigator Company for providing financial support to the PhD scholarship granted to Daniel Pio (ref. PD/BDE/128620/2017).