In Situ Raman Spectroscopy Study on Catalytic Pyrolysis of a Bituminous Coal

摘要

How different catalysts would affect the evolution of char structure with increasing temperature during the pyrolysis of coal is fundamentally important for the clean utilization of coal. In this Study,,we applied in situ Raman spectroscopy and a fixed-bed reactor to characterize the evolution of char structure and product gas formation behavior. The results showed that the formation curves of the main gases presented two stages and the catalyst enhanced the pyrolysis significantly. The Raman spectra were fitted with a combination of four Lorentzian bands, (D1, D2, D4, one Gaussian band (D3) in the first-order region. Spectral parameters, such as hand position, full widths at half-maximum (FWPIM), and hand area ratio, were used to characterize char structure. The DI and G band FWHM and band area ratios ID1/I-G,ID3/I-G, and ID4/1(G) increased with increasing temperature, while the DI and G band positions and I-G/IA(ll) decreased, indicating, a decrease in the ordering of the char structure. The. addition of catalyst led to a lower degree of char structural order. Thermogravimetric analysis was also used to measure the reactivity of char derived from pyrolysis, and the results showed a good,correlation between reactivity Indexes and I-G/IA(II).