Pyrolysis of Coal Microparticles under the Influence of Nanosecond Laser Pulses
B. P. Aduev, Y. V. Kraft, V. D. Volkov, N. V. Nelyubina
Federal Research Center of Coal and Coal Chemistry, Siberian Branch, Russian Academy of Sciences, Kemerovo, Russia
Keywords: coal, pyrolysis, laser radiation, optical breakdown, mass spectrometry, ablation
Abstract
The paper presents the results of pyrolysis of tableted microparticles (1 g/cm3) of brown, long-flame gas, gas, fat and coke coals in an argon environment under the action of laser pulses (1064 nm, 12 ns, 6 Hz, 0.2 ÷ 0.5 J/cm2), which results in a number of nonlinear processes: 1) ablation of explosive samples with the emission of microparticles of 10 ÷ 60 μm in size upon reaching a radiation energy density of 0.1 ÷ 0.2 J/cm2; 2) optical breakdown localized on microprotrusions on the surface of coal particles, evaporation of microprotrusions and deposition of a thin film of amorphous carbon on the reactor walls; 3) initiation of thermochemical reactions in the breakdown channels, leading to the release of gaseous products, the concentration of which nonlinearly increases with an increase in the energy density of laser pulses. Molecular gases H2, CH4, C2H2, CO, CO2 were registered. Dependences of the composition of gaseous products of coal pyrolysis on their technical and genetic characteristics were established.
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