The application of biomass-derived energy is gaining in importance due to decreasing supply of fossil
fuels and growing environmental concerns. In this study, hydrothermal carbonization was used to
upgrade waste biomass and increase its energy density at temperatures ranging from 150 to 375 C
and a residence time of 30 min. The produced biochars were characterized and their fuel qualities were
evaluated. The biochars were found to be appropriate for direct combustion/co-combustion with low
rank coals for heat production. Chemical analysis showed that the pre-treated biomass has improved fuel
qualities compared to the raw biomass, such as decreased volatile matter/(volatile matter + fixed carbon)
ratio, increased carbon content and lower ash content. The energy density of biochar increased with
increasing hydrothermal temperature, with higher heating values close to that of lignite. The evolution
of biomass under hydrothermal carbonization, as determined by FT-IR and 13C NMR, showed that most
hemicellulose and cellulose were decomposed at below 250 C while the degradation of lignin only
occurs at higher temperatures. The aromaticity of biochars increased with increasing temperature, and
considerable amounts of lignin fragments remained in the biochars after supercritical water treatment.
The biochars had increased ignition temperatures and higher combustion temperature regions compared
to raw biomass feedstock. An optimum temperature of 250 C was found for hydrothermal carbonization
of waste biomass for the production of biochars for heat generation. The present study showed that
hydrothermal carbonization narrowed the differences in fuel qualities among different biomass feedstocks.
It also offers a promising conversion process for the production of high energy density biochar
which has potential applications in existing coal-fired boilers without modifications.
The application of biomass-derived energy is gaining in importance due to decreasing supply of fossilfuels and growing environmental concerns. In this study, hydrothermal carbonization was used toupgrade waste biomass and increase its energy density at temperatures ranging from 150 to 375 Cand a residence time of 30 min. The produced biochars were characterized and their fuel qualities wereevaluated. The biochars were found to be appropriate for direct combustion/co-combustion with lowrank coals for heat production. Chemical analysis showed that the pre-treated biomass has improved fuelqualities compared to the raw biomass, such as decreased volatile matter/(volatile matter + fixed carbon)ratio, increased carbon content and lower ash content. The energy density of biochar increased withincreasing hydrothermal temperature, with higher heating values close to that of lignite. The evolutionof biomass under hydrothermal carbonization, as determined by FT-IR and 13C NMR, showed that mosthemicellulose and cellulose were decomposed at below 250 C while the degradation of lignin onlyoccurs at higher temperatures. The aromaticity of biochars increased with increasing temperature, andconsiderable amounts of lignin fragments remained in the biochars after supercritical water treatment.The biochars had increased ignition temperatures and higher combustion temperature regions comparedto raw biomass feedstock. An optimum temperature of 250 C was found for hydrothermal carbonizationof waste biomass for the production of biochars for heat generation. The present study showed that
hydrothermal carbonization narrowed the differences in fuel qualities among different biomass feedstocks.
It also offers a promising conversion process for the production of high energy density biochar
which has potential applications in existing coal-fired boilers without modifications.
การแปล กรุณารอสักครู่..