Development of a microwave reactor for the combustion of particles

The carcinogenicity of combustion generated fine particles is no longer speculative. Among others, special attentions are recently giving to the fine particles from the biomass combustion plants as a prior research interest to the development of bioenergy. Under the world ever growing population and her energy demand, the particles emission is supposedly and correspondingly increased. The paradigm applications of microwave in the field of particles emission control technology is becoming overwhelmingly clear; a prominent example is the microwave assisted regeneration of DPF. Nevertheless, the development of a retroffitable microwave system is still very challenging because of the complex and multiple processes involved. The computer-based CEM technique can be employed to develop an adequate solution model capable of concurrently solving the cross-linked mechanisms and processes involved (e. g. electromagnetic, heat transfer, mass transfer and momentum transfer). In the first part of this study, the innovative computer-based simulation was exploited to accompany the development of a microwave reactor; while the second part was dealt with the experimental investigations into the combustion characteristics of particles on the constructed reactor. A cylindrical resonant applicator with coaxially inserted quartz glass column was designed with the heating system operating at a frequency of 2.45 GHz and a magnetron of 1200 W. Interactive and constitutive 3-D simulation models that replicated the totality of the applicator structure and the processed material were developed using CST-MWS and COMSOL-Multiphysics packages, conformal of FEM and FIT methods. The electromagnetic and thermal simulations were implemented to model, evaluate and optimise the electric field performances and temperature distributions in the applicator and in the gas-particles flow path; among the pertinent parameters taking into account are gas-particles mixture properties, applicator and system parameters. Based on the results, a modular reactor was constructed and experimentally verified. The components of the reactor include: applicator system, particles loading and airflow, gas filtration, measurement and data acquisition device.