The mechanism of microwave-induced discharge between submillimeter active coke

Abstract

Microwave-induced active coke discharge has been used in much research related to the environment and energy due to its kinetics and thermal effect. However, the mechanisms of discharge for submillimeter particles are still not clear. This paper presents evidence that the particle shape and gap distance between particles are the possible mechanisms of the microwave discharge. This paper also gives the scope of application of several mechanisms for different particulate materials. Submillimeter particles with about 40-110 • tip angle and micron gap distance have the best effect on microwave electric field enhancement. The gap effect is only applicable to materials with a large refractive index, in detail, n > 3 or k > 2 for a 300 μm particle. When the gap distance is too narrow, the electron loss from gap to particle surfaces is large enough, leading to the failure of discharge.

Production Characteristics of Volatiles from Anthracite Cracking via Microwave-Induced Discharge

“…As shown in Figure , the generation rate of electronic excited-state molecules is k Ar N e N Ar + k N 2 N e N N 2 , where k Ar and k N 2 are the reaction rate constants of electronic excited-state argon and nitrogen, respectively; and N e , N Ar , and N N 2 are the number densities of electron, argon, and nitrogen, respectively. Considering the low ionization degree (much less than 1%) of microwave-induced discharge under ∼1 kW microwave at atmospheric pressure, ,, the number of argon and nitrogen molecules is approximately equal to xN g + (1 – x ) N g , where x is the argon content and N g is the number of molecules of gas. Therefore, the generation rate of electronic excited-state molecules is proportional to [ xk Ar + (1 – x ) k N 2 ] N e , abbreviated as kN e , where k is the total electronic state excitation rate constant.…”