Papers by Keyword: Microwave Absorbent

Abstract: The present paper decribed the effects of carbocoal on temperature rising characteristic during coal pyrolysis at different temperature in microwave field. Different mixture rate of carbocoal with coal and different final temperature on coal pyrolysis tempereature rising characteristics were studied in the work. The results indicate: Coal is a poorly microwave absorbing material. Because carbocoal can be fast heated in microwave field, so it can be used as additive for coal pyrolysis. Carbocoal otained from different pyrolysis temperature have different heating rate, along with the increase of carbocoal pyrolysis temperature, carbocoal heating rate increases in microwave field. Using carbocoal as microwave absorbent for coal rapid pyrolysis in microwave field is feasible.

Abstract: The microwave thermal conversion process of oil sludge was studied. It was found that the microwave thermal conversion process of oil sludge consisted of 5 stages: rapid heating, microwave drying, microwave hydrocarbons evaporation, microwave pyrolysis and microwave calcining. Using the residue produced from the microwave thermal treatment of oil sludge as a microwave absorbent can significantly accelerate the conversion. However, it does not show significant effect on the features of microwave thermal conversion. Meanwhile, the addition of residue at appropriate percentages increased oil recovery rate. The non-condensable gases consist of H2 and C1~C5 hydrocarbons. The recovered oil was mainly produced at microwave evaporation and microwave pyrolysis stages, consisting of 89% light oil and 11% heavy oil.

Abstract: In order to compare the absorbing properties of different microwave-absorbing agents and their mixture, this paper has selected two typical microwave-absorbing agents which respectively are carbon fiber resistance microwave-absorbing agents and ferrite magnetism microwave-absorbing agents, and took them as monolayer absorbing materials. Then used MG formula to calculate the effective electromagnetic parameter of their mixture under different proportion at X band, and finally analyzed their absorbing properties separately. Then through contrasting the impedance matching characteristic and attenuation coefficient of the materials, it is proved that adding carbon fiber in ferrite can not improve absorption properties. Although the ability of attenuating electromagnetic wave would be enhanced when resistance materials and magnetism materials are blend with each other, doping will destroy the materials’ impedance matching characteristic because most resistance materials have high permittivity. It makes reflection strengthen and can not improve absorbing properties.

Abstract: The pesent paper decribed the effects of additive on temperature rising characteristic during coal pyrolysis at different temperature in microwave field. Different mixture rate of carboncoal with coal and different final temperature on coal pyrolysis tempereature rising characteristics were studied in the work. The results indicate: Coal is a poorly microwave absorbing material, and its pyrolysis in microwave field need to add a certain amount of microwave absorbent for higher heating rate; Because carbocoal can be fast heated in microwave field, so it can be used as additive for coal pyrolysis. Carbocoal otained from different pyrolysis temperature have different heating rate, along with the increase of carbocoal pyrolysis temperature, carbocoal heating rate increases in microwave field. Using charcoal as microwave absorbent for coal rapid pyrolysis in microwave field is feasible.