Summary: | Tar in biomass producer gas should be removed to avoid blocking of the pipe
lines and to allow producer gas utilization in internal combustion (IC) engines and
turbines for power generation. Among the available tar removal methods, thermal and
catalytic (thermocatalytic) treatments of tar are more attractive with improvement of the
producer gas energy content by converting tar into combustible gases. The alternative
method by using microwave heating and water addition is cost effective, clean energy
source, simple and potential for process scale up. A modified commercial microwave
oven was developed and characterized for thermocatalytic treatment of tar. Tar removal
was conducted initially using tar model compounds (toluene and naphthalene) followed
by real tar from producer gas derived from biomass gasification. Tar species and gases
were analyzed using Gas Chromatography-Mass Spectrometry (GC-MS) and Gas
Chromatography-Thermal Conductivity Detector (GC-TCD), respectively.The
experimental results showed that thermal heating process under low energy consumption
of microwave irradiation is suitable for thermocatalytic treatment of tar. For tar model,
about 95% of both toluene and naphthalene were removed during thermal treatment at
temperatures of 10500C and 12000C, respectively. In catalytic treatment, about 99%
toluene and 97% naphthalene were removed using dolomite at 8500C and 9000C
respectively, whereas about 97% toluene and 95% naphthalene were removed using Yzeolite
at 7000C. Further in the treatment of nickel 99% toluene and 97% naphthalene, while ruthenium was found to be 99% and 96%, while the last treatment with rhodium
has eliminated 96% toluene and 95% naphthalene.
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