Page 282 - Lignocellulosic Biomass to Liquid Biofuels

236 Lignocellulosic Biomass to Liquid Biofuels

to account for intraparticle dispersion restrictions, which further explored
by Wang et al. [133]. Co catalysts-based heterogeneous and single-
dimensional model for FPBR was proposed by de Swart et al. [134].A
comprehensive software package developed by Fernandes and Cartaxo
[135] for FT process in a SPR was used to simulate the overall reactor
conditions. This study integrated three phases (gas, slurry, and solid phase)
and different catalysts and could be adopted different synergy of these
mechanisms. However, it was demonstrated that these three mechanisms
are not accurate to describe the overall process and the kinetic parameters
in their software could not be modified. Furthermore, a numerical model
is simulated to evaluate the FT process in tubular multitube reactor using
Fe-based catalyst to investigate the impact of process parameters on
hydrocarbon production [48]. Kwack et al. [79] used lsqcurvefit in
MATLAB to simulate the product distribution during FT synthesis on Co
catalyst using a revised mechanism. Also, Kshetrimayum et al. [136] pro-
posed a detailed computational fluid dynamics simulated modeling for FT
process in packed microchannel reactor, considering both single and mul-
tichannel reactor. Therefore it was suggested that the temperature effect
on CO conversion and the selectivity of hydrocarbon products revealed
necessity for maintaining a reaction channel temperature below 250°C,
during FT process under low-temperature conditions. In general, the
research on simulations was fragmented, and there was no software
packages to perform complete simulations, which should include the feed-
stock and kinetic parameter specifications, modeling of diffusion limitation
graphical description of syngas consumption, and hydrocarbon production
rate [79,136,137].

7.6 Carbon nanofibers/Carbon felt reactors

Natural gas, coal, or biomass that is converted into syngas could be fur-
ther transformed in liquid hydrocarbons via FT synthesis. It is extremely
exothermic reaction and effective heat transfer is prerequisite for suc-
cessful operation. The selectivity for C 51 hydrocarbons highly deepens
on appropriate catalysts selection, temperature profile of reactor, and
gas liquid mass transfer rate, and reactors deign is key factor to achieve
high selectivity. Mostly, the fixed-bed and slurry SPRs were used for
the FT synthesis. To attain high catalyst efficiency and C 51 hydrocar-
bons selectivity the heat removal is a major challenge in these reactors.
Moreover, large units are favored but applications such as offshore