Title:
Lignocellulosic Energy Crops Combustion Operation Conditions Impact on their Bottom Ashes Transformation Behaviour and Fractionation Based on Pilot-Scale and Full-Scale Measurements
Author(s):
Díaz, M., Sebastián, F., Boström, D., Boman, C.
Document(s):
Paper
Abstract:
Availability of traditional biomass fuels such as woody sources for the heating market is restricted to economic considerations (e.g. consumption in paper industries) and locations of these raw materials for pellets production. In Spain, non-traditional biomass sources such as Mediterranean energy crops are starting to be seen as potential future biomass fuels. However, due to their complex chemical composition, they might require specific combustion technologies adapted to their combustion behaviour. Focused on this goal, the main objective of this work was the assessment of combustion operation conditions on bottom ashes transformation behaviour and fractionation of two Mediterranean energy crops (Brassica carinata and Populus ssp.). Two different sizes appliances, a small and a medium grate biomass pellet boiler with a nominal heat output of 25 kWth and 250 kWth respectively, were used to perform the combustions experiments of this work. Evaluation of the fuels in the combustion tests included the collection of samples of slag and bottom ashes, as well as measurements of gaseous compounds (O2, CO, NO/NOx,). All the samples were analysed by means of scanning electron microscope (SEM-EDS) for elemental composition and the X-Ray diffraction for crystalline phase composition. The experimental results revealed that the combustion behaviour of these fuels regarding ash-related problems were due to both their high ash content and proportion of major ash-forming elements (Ca-K-Si-S-P-Mg). However, the melting and sintering behaviour of their ashes were also influenced by means of factors like changes in the combustion conditions due to parameters such as bed movement on the grate, bed temperature, concentration of inorganic gaseous species and air distribution.
Keywords:
ashes, conversion systems, energy crops, pellets
Topic:
Thermochemical conversion - Combustion for small scale applications
Subtopic:
Combustion for small scale applications
Event:
18th European Biomass Conference and Exhibition
Session:
VP2.5.12
Pages:
1316 - 1320
ISBN-13:
978-88-89407-56-1
ISBN-10:
88-89407-56-5
Paper DOI:
10.5071/18thEUBCE2010-VP2.5.12
Price:
FREE
