Clean Desulphurization of High-Sulfur Coal Based on Synergy Effect between Microwave Pretreatment and Magnetic Separation

Abstract

Coal is the world’s second largest energy resource and the primary energy resource in China. Coal-fired power generation is the dominant source for obtaining power both in China and the world. This situation is considered to remain unchanged for the coming few decades. The paper is to study the mechanism of microwave absorption capacity of the magnetic medium. A mechanism for the microwave energy absorption of fine coal is proposed by obtaining the parameters of dielectric properties of the magnetic medium. The prediction model of electromagnetic parameters during the process of microwave dielectric enhancement of fine coal is established by using the neural network method. The content of magnetic medium, by increasing the electromagnetic parameters to improve the energy utilization rate and reduce energy loss, can effectively improve the absorption and broaden bandwidth of the coal sample, improving the frequency adaptive design of coal by the microwave pretreatment process. A neural network model for the prediction of the electromagnetic parameters of fine coal is established by using the neural network method. The desulfurization rates were 23.99 and 45.78% for Weinan and Lu’an coals, respectively.

Simulation Study on the Interaction between Chemically Reacting Double Coal Char Particles

“…China’s main source of energy production is coal. , It is the world’s largest coal producer and consumer . In the past, coal was used only for heating, which would cause serious environmental pollution.…”

Microwave absorption properties and quantum chemistry of organic sulfur compounds in coal

“…3 Microwaves have the characteristics of selectivity, penetration, and bulk heating, which can promote chemical reactions, accelerate the reaction rate, and increase the yield. [4][5][6][7] By taking advantage of the difference in microwave absorption capacity between coal matrix and organic sulfur compounds, the organic sulfur compounds in coal can generate local high temperature and dissociate reaction through microwave radiation within a very short time before the coal matrix is decomposed. 8,9 The response of the medium to microwave depends on its own dielectric characteristics.…”

“…Organic sulfur in coal is generally embedded in organic matter and is difficult to remove; its main forms include mercaptan, sulfide, thiophene, sulfone, and sulfoxide 3 . Microwaves have the characteristics of selectivity, penetration, and bulk heating, which can promote chemical reactions, accelerate the reaction rate, and increase the yield 4–7 . By taking advantage of the difference in microwave absorption capacity between coal matrix and organic sulfur compounds, the organic sulfur compounds in coal can generate local high temperature and dissociate reaction through microwave radiation within a very short time before the coal matrix is decomposed 8,9 .…”