TITLE:
Numerical Analysis on Wood Pyrolysis in Pre-Vacuum Chamber
AUTHORS:
Hiroki Homma, Hiroomi Homma, Muhammad Idris
KEYWORDS:
Pyrolysis, Pre-Vacuum Chamber, Chemical Reaction, Volatile Sublimation, ANSYS Fluent
JOURNAL NAME:
Journal of Sustainable Bioenergy Systems,
Vol.4 No.3,
August
22,
2014
ABSTRACT: In the previous experimental work, a new technology system for wood
pyrolysis was developed to aim at mitigating climate change, global warming,
and energy crisis as well as enhancing low electrification in rural areas in
developing countries. The new technology system equipped with a pre-vacuum
chamber requires low cost and less maintenance. However, large wood pyrolysis
in the pre-vacuum chamber is rather complicated. To obtain a good understanding
of the previous experimental results, a numerical analysis taking account of
heat-mass transfer and chemical reaction is carried out. Two-step general
reaction model is proposed for the numerical analysis. The first stage is
volatile and char formation from the wood pieces and the second state is
decomposition of the volatile to five species including vapor of tar. In this
analysis, chemical formulae of the volatile and the tar are successfully
identified hypothetically. The results obtained by this numerical analysis can
explain the experimental results reasonably and provide useful information
about time evolution of volatile formation, temperature change in pre-vacuum
chamber with time, and species mole concentration decomposed from the volatile.