experiments, resulting in an inaccurate calculation of product yields with the use of a
simple law on additives. In addition, the pyrolysis products of each component of the
biomass have been characterised to study their contribution to the yield and composition of products from complete biomass pyrolysis. A study of the pyrolysis
reaction paths of each component was also carried out, using the characterisation
data of the bio-oil of this study and those found in the literature.
Zhang et al. (2007) carried out the co-pyrolysis of biomass and coal in a free-fall
reactor under atmospheric pressure with nitrogen as equilibrium gas. The chosen
coal sample was Dayan brown coal, while the biomass used was leguminous straw.
The working temperature was between 500 and 700
C, and the mixing ratio of the
biomass in the mixtures varied between 0% and 100% by weight. The results
showed that there were synergistic effects in the co-pyrolysis of biomass and coal.
Under the conditions of the higher mixing ratio, the carbonisation yields are lower
than the theoretical values calculated for the pyrolysis of each individual fuel, and
therefore the liquid yields are higher. Moreover, the experimental results showed
that the compositions of the gaseous products from the mixed samples do not all
conform to those of the parental fuels. CO 2 reactivities of carbonates from
co-pyrolysis under higher mixing ratio conditions (about 70% by weight) are
about twice as high as those of the carbonator alone or even higher than those of
the biomass alone.
Chen et al. (2003) focused on the use of catalysts for the production of gaseous
hydrogen from biomass. The use of cheap biomass as a source of thermochemical
conversion is a good way to produce hydrogen. Hydrogen is a clean and efficient
energy source and should play an important role in future energy demand. Various
types of catalysts have been studied on our test bench at wide operating temperature
ranges. The results show that the catalyst has a positive influence on the hydrogenrich gas yield. The hydrogen concentration of the pyrolytic gas is significantly
improved by some types of catalysts. The results obtained here can be very useful
for large-scale hydrogen production based on the biomass source.
Shen et al. (2009) investigated the effect of the particle size of the biomass
(0.18–5.6 mm) on the yield and the composition of the result bio-oil from pyrolysis
of woody biomass Dutch mallee in a reactor fluidised bed at 500
C. The yield of
bio-oil decreased when the average particle size of the biomass increased from 0.3 to
about 1.5 mm. Subsequent increase in the particle size of the biomass did not result
in a further reduction in the yield of bio-oil. These results are mainly due to the
impact of particle size in the production of lignin-derived compounds. The possible
interactions between vapour particles of bio-oil and coal particles or vapours of
homogeneous reactions are not responsible for the decrease in the yield of bio-oil.
Samples of bio-oil were characterised by thermogravimetric analysis, UV fluorescence spectroscopy titration Karl Fischer and precipitation in cold water. It was
found that the yield of light bio-oil fractions increased and those heavy bio-oil
fractions decreased with increasing the size of the biomass particles. The pyrolytic
formation of water at low temperature (<500
C) is little influenced by the temperature or the particle size. It is believed that the decrease in the heating rate of coarse
particles is an important factor responsible for the low yields of large particle bio-oil
12 Modelling and Simulation of Pyrolysis of Teak (Tectona Grandis) Sawdust
339
simple law on additives. In addition, the pyrolysis products of each component of the
biomass have been characterised to study their contribution to the yield and composition of products from complete biomass pyrolysis. A study of the pyrolysis
reaction paths of each component was also carried out, using the characterisation
data of the bio-oil of this study and those found in the literature.
Zhang et al. (2007) carried out the co-pyrolysis of biomass and coal in a free-fall
reactor under atmospheric pressure with nitrogen as equilibrium gas. The chosen
coal sample was Dayan brown coal, while the biomass used was leguminous straw.
The working temperature was between 500 and 700
C, and the mixing ratio of the
biomass in the mixtures varied between 0% and 100% by weight. The results
showed that there were synergistic effects in the co-pyrolysis of biomass and coal.
Under the conditions of the higher mixing ratio, the carbonisation yields are lower
than the theoretical values calculated for the pyrolysis of each individual fuel, and
therefore the liquid yields are higher. Moreover, the experimental results showed
that the compositions of the gaseous products from the mixed samples do not all
conform to those of the parental fuels. CO 2 reactivities of carbonates from
co-pyrolysis under higher mixing ratio conditions (about 70% by weight) are
about twice as high as those of the carbonator alone or even higher than those of
the biomass alone.
Chen et al. (2003) focused on the use of catalysts for the production of gaseous
hydrogen from biomass. The use of cheap biomass as a source of thermochemical
conversion is a good way to produce hydrogen. Hydrogen is a clean and efficient
energy source and should play an important role in future energy demand. Various
types of catalysts have been studied on our test bench at wide operating temperature
ranges. The results show that the catalyst has a positive influence on the hydrogenrich gas yield. The hydrogen concentration of the pyrolytic gas is significantly
improved by some types of catalysts. The results obtained here can be very useful
for large-scale hydrogen production based on the biomass source.
Shen et al. (2009) investigated the effect of the particle size of the biomass
(0.18–5.6 mm) on the yield and the composition of the result bio-oil from pyrolysis
of woody biomass Dutch mallee in a reactor fluidised bed at 500
C. The yield of
bio-oil decreased when the average particle size of the biomass increased from 0.3 to
about 1.5 mm. Subsequent increase in the particle size of the biomass did not result
in a further reduction in the yield of bio-oil. These results are mainly due to the
impact of particle size in the production of lignin-derived compounds. The possible
interactions between vapour particles of bio-oil and coal particles or vapours of
homogeneous reactions are not responsible for the decrease in the yield of bio-oil.
Samples of bio-oil were characterised by thermogravimetric analysis, UV fluorescence spectroscopy titration Karl Fischer and precipitation in cold water. It was
found that the yield of light bio-oil fractions increased and those heavy bio-oil
fractions decreased with increasing the size of the biomass particles. The pyrolytic
formation of water at low temperature (<500
C) is little influenced by the temperature or the particle size. It is believed that the decrease in the heating rate of coarse
particles is an important factor responsible for the low yields of large particle bio-oil
12 Modelling and Simulation of Pyrolysis of Teak (Tectona Grandis) Sawdust
339