Title:
Pneumatic Transport of Torrefied Biomass in Dilute and Dense Phase
Author(s):
Mourao Vilela, C.F., Abelha, P.
Document(s):
Paper
Abstract:
Pulverized coal combustion and entrained flow gasification are two of the main technologies worldwide that use coal as feedstock. In a coal-fired power plant the pulverized fuel is transported pneumatically with air in dilute phase to the boiler whereas in the second case the coal is entrained into the gasifier in dense phase. Biomass could be an option for the direct replacement of coal, however several past experiences with co-firing have shown several limitations using this feedstock, among which the pneumatic conveying. Torrefaction, followed by densification, is a process that can improve the characteristics of the biomass. However, the behavior of torrefied biomass during pneumatic transport has not been investigated in much detail. The present work will show the pneumatic conveying behavior of coal, raw and torrefied biomass at dilute phase and dense phase. Complementary work on grindability and fluidization will be provided for a better insight. About 25% less gas is necessary to transport torrefied biomass in dilute phase and about 2-3 times more is transported in dense phase when compared with raw biomass. The present work pinpoints the role of particle morphology in the pneumatic transport and how milled torrefied biomass pellets resemble coal particles. There is an attempt to correlate all the results (grindability, fluidization and pneumatic transport) with the defined variable f (flowability), a simple ratio that has the potential to give a preliminary and easy assessment of the morphological properties of a given material and its expected pneumatic behavior.
Keywords:
coal, feeding systems, torrefaction, pretreatment, wood pellet
Topic:
Biomass Conversion Technologies for Heating, Cooling and Electricity
Subtopic:
Production and supply of solid fuels and intermediates
Event:
27th European Biomass Conference and Exhibition
Session:
2DO.7.3
Pages:
624 - 629
ISBN:
978-88-89407-19-6
Paper DOI:
10.5071/27thEUBCE2019-2DO.7.3
Price:
FREE
