Numerical Investigation of Supersonic Hybrid Argon–Water-Stabilized Arc for Biomass Gasification
This paper presents a numerical simulation of temperature and flow fields in the discharge and near outlet regions of the hybrid argon-water-stabilized electric arc. The calculations for an argon mass flow rate of 0.450 g ldr s-1 reveal the transition from a transonic plasma flow for 400 A to a supersonic one for 600 A with the maximum Mach number of 1.57. The comparison with available experimental data for 400 A shows satisfactory agreement.
A review on the pyrolysis of woody biomass to bio-oil: Focus on kinetic models
The thermal decomposition of woody biomass in the absence of oxygen, or pyrolysis, is a series of complex reactions involving hundreds of compounds. The species of residue, form of residue (bark, sawdust, and other residues), age, storage conditions, among other factors, will impact the composition of the residue which in turn impacts the pyrolytic reactions. The reaction rates must be understood to optimize the pyrolysis reactor. However, the determination of intrinsic kinetics in this system is complex (both due to feedstock composition and the nature of reactions at pyrolysis temperatures) and as such the approach has been to use an overall reaction rate or series of simplified reactions. In this study, a review of large scale pyrolysis process units, reactor mathematical models, mechanisms for conversion of woody biomass and overview of heat of pyrolysis is presented. In addition, the presented kinetic models have been compared to experimental data obtained from pyrolysis of different liginocellulosic biomass (i.e. sawdust, bark, and wood chips) in a lab-scale tube furnace reactor, to determine the “best” kinetic model for the fast pyrolysis of sawmill residues. The results show that the chemical percolation devolatilization model (Lewis et al. Energy Fuels 2013; 27:942–953. doi:10.1021/ef3018783) predicts the pyrolysis products most accurately. Furthermore, the competitive model (Chan et al. Fuel 1985; 64:1505–1513. doi:10.1016/0016-2361(85)90364-3) shows very good agreement for bio-oil experimental data. Although the pyrolysis of biomass has been widely investigated in recent decades, the models have some limitations which could limit their application to a broad spectrum of feedstock and pyrolysis operating conditions.
Biomass Pyrolysis in an Argon/Hydrogen Plasma Reactor
This paper presents the experimental results of biomass pyrolysis in a laboratory argon/hydrogen plasma reactor. The samples tested were wood and rice husk. The gaseous product was found to contain mainly H2, CO, C2H2 and CH4. The conversion of carbon and oxygen from the biomass feed to gaseous product can reach up to 79 % and 72 %, respectively. The results indicate that plasma pyrolysis of biomass may be a useful way for gaseous fuel production.