abstract
Bottom bed waste (BBW) from combustion of forest biomass residues was characterized aiming its use as partial substitute of fresh bed sand (FBS) in industrial bubbling fluidized bed combustors (BFBC). BBW partide size distribution, elemental composition (mainly Si, Ca, Al, Na, K, P and Mg) and mineralogy were evaluated considering also the influence of the characteristics of the biomass used as fuel. Biomass combustion experiments were developed using a pilot-scale bubbling fluidized bed combustor. The operating conditions during the experiments were monitored, namely the flue gas composition (CO2, O-2 and CO), temperature and pressure, and compared with data collected from BFBC located in two industrial biomass thermal power plants. Physical, chemical and mineralogical characteristics of the FBS and BBW revealed that practices related with biomass handling at the forest strongly influence the BBW properties, in terms of not only coarse soil particle addition (>1.0 mm) but also mineralogically. However, the results obtained here indicate that by sieving of BBW it is possible to recover almost 60% of the original BBW particles (size between 0.3 and 1.0 mm), which have properties that allow its reuse as substitute of FBS for bed make-up in industrial BFBC. (C) 2014 Elsevier B.V. All rights reserved.
keywords
AGGLOMERATION CHARACTERISTICS; PARTICLE AGGLOMERATION/DEFLUIDIZATION; CONCENTRATION PROFILES; ASH FORMATION; FUELS; INCINERATION; CONVERSION; BOILERS; SLUDGE; WOOD
subject category
Chemistry; Energy & Fuels; Engineering
authors
Modolo, RCE; Tarelho, LAC; Teixeira, ER; Ferreira, VM; Labrincha, JA
our authors
João António Labrincha Baptista
Full professor
Regina Célia Espinosa Modolo
PhD Student
Victor Miguel Carneiro de Sousa Ferreira
Associate Professoracknowledgements
The authors acknowledge the Foundation for Science and Technology (FCT - Portugal) for the financial support (SFRH/BD/75182/2010 - PhD Grant, and the Projects PTDC/AAC-AMB/098112/2008 - Bias-to-soil - biomass ash: characteristics in relation to its origin, treatment and application to soil, and PTDC/AAC-AMB/116568/2010 - BiomAshTech - ash impacts during thermo-chemical conversion of biomass).