Steam catalytic cracking of coal tar over iron‐containing mixed metal oxides

Abstract

Steam catalytic cracking is deemed as a promising method for the catalytic cracking of coal tar. In this study, a serial of iron-containing mixed metal oxides including ceria, zirconia, alumina, cobalt, nickel, and barium oxides were prepared for steam catalytic cracking of coal tar and characterized by N 2 adsorption-desorption, X-ray diffraction, H 2 temperature programmed reduction, and Raman spectroscopy, respectively. It was found that the specific surface area and pore volume increase while the crystal size decreases when Fe 2 O 3 was doped with the investigated metal oxides. Among these, iron-alumina mixed oxide (FeAl) shows the highest specific surface area and pore volume. The H 2 -TPR analysis indicated that most of the mixed metal oxides have lower reduction temperature, especially for iron-ceria mixed oxide (FeCe). The reduction temperature of FeCe is around 500 8C, and its reduction peak shifts to a lower temperature and becomes narrower as compared to other iron-containing mixed metal oxides. The steam catalytic cracking of coal tar at 550 8C showed that the light tar content (below 360 8C) over FeCe, FeCo, and FeAl are 68.5, 67.0, and 66.5 %, respectively. The increase of CO 2 and H 2 over iron-containing mixed metal oxides suggested that oxygen species from iron-containing mixed metal oxides and steam could participate in the steam catalytic cracking of coal tar.

Catalytic aerobic oxidation of lignin-based vanillyl alcohol under base–free conditions over an efficient and reusable LaFeO3 perovskite for vanillin production

“…For example, desorption of each lattice oxygen atom from the perovskite surface produces an oxygen vacancy, while the oxygen in the perovskite bulk will transfer to the surface to fill the oxygen vacancies. 72,73 More adsorbed oxygen implies the existence of more oxygen vacancies and a higher amount of quasi-free electrons in perovskite oxides. 74 By capturing electrons, the adsorbed oxygen results in generating O 2 − with the assistance of O 2 supply, which is the active centre for oxidation.…”

Experimental methods in chemical engineering: Raman spectroscopy

“…Eng. published 11 articles: six are directly related to catalysis, [27][28][29][30][31] three are in the area of combustion, [32] one combined Raman and EDS to identify a low melting lithium phosphate phase in lithium iron phosphate ingots, [33] and another applied confocal Raman to measure solute concentrations in a hanging droplet (mass transfer). [34] Raman spectrographs now record the whole spectral range (Raman shifts from 100 cm −1 to 4000 cm −1 ) at subsecond resolution and are applied to pulse experiments with isotopes, to measure reaction kinetics and spectroscopic characteristics.…”

“…Eng . published 11 articles: six are directly related to catalysis, [ 27–31 ] three are in the area of combustion, [ 32 ] one combined Raman and EDS to identify a low melting lithium phosphate phase in lithium iron phosphate ingots, [ 33 ] and another applied confocal Raman to measure solute concentrations in a hanging droplet (mass transfer). [ 34 ]…”