Coats-Redfern integral method combined with TG-MS technology was applied to study the evolution of the main pyrolysis products for Shenmu bituminous coal. And a heat transfer, reaction, numerical model of coal pyrolysis by gas heat carrier in a moving-bed reactor is developed. The model can predict the internal temperature profile and pyrolysis volatiles evolution of different coal species as well as the temperature distribution of gas heat carrier versus bed height. The results show that, when the temperature of gas heat carrier increases from 700°C to 900°C, the theoretical bed height of pyrolysis drops from 0.26 m to 0.14 m, and the maximum of devolatilization rate increases from 0.954 %·s -1 to 1.382 %·s -1 . The coal species have significant influence on their temperature-rise pyrolysis process in a gas heat carrier moving-bed reactor. Higher initial temperature or velocity of gas heat carrier, smaller particle size or moving velocity of coal tends to accelerate the devolatilization rate and shorten the pyrolysis time. This work may provide a theoretic foundation for the reactor amplification and different industrial condition prediction of high-volatile coal pyrolysis in a moving-bed reactor.

To improve the degradation efficiency of TiO 2 for low concentrations of volatile organic compounds, TiO 2 loaded on activated carbon fibres (ACF) was prepared by an impregnation-hydrothermal method. The crystal structure, surface area, dispersion, optical absorption properties, and chemical composition of the TiO 2 /ACF composite materials were characterised by X-ray diffraction, Brunauer−Emmett−Teller analysis, scanning electron microscopy, ultraviolet-visible absorption spectroscopy, and X-ray photoelectron spectroscopy. The influence of the hydrothermal temperature, illumination time, space velocity, and light intensity on the photocatalytic activities of the TiO 2 /ACF composite materials was investigated with toluene as a model pollutant. The results showed that the phase of TiO 2 was anatase, which was dispersed as a thin film on the ACF surface. The crystallinity, dispersion, UV absorption, and hydroxyl group content of TiO 2 increased with an increase of hydrothermal temperature, whereas the photocatalytic activity of TiO 2 /ACF was maximised when the hydrothermal temperature was 180°C. Increases in illumination time, space velocity, and light intensity were beneficial for regeneration of the composite materials. However, the energy efficiency decreased with increased light intensity. The degradation efficiency of toluene reached 40% with reaction conditions of illumination time: 3 h, space velocity: 1400 h −1 , and light intensity: 32 W. This degradation efficiency decreased 3.3% after recycling five times.

Two catalysts, 2%NiO/1%CeO 2 −Al 2 O 3 and 2%NiO/1%CeO 2 /2%ZrO 2 −Al 2 O 3 , were employed in the conversion of tar in coal pyrolysis volatiles to investigate the interrelationship between dust collection and tar cracking as well as the effect of Ce/Zr doping on catalyst performance. In a fixed-bed catalytic reactor, a tar model mixture (57 wt % toluene, 14 wt % methylnaphthalene, 14 wt % cyclohexane, and 15 wt % dodecane) and simulated dusts (various metal oxides) were introduced to mimic real coal pyrolysis volatiles. The catalytic cracking activity of the latter catalyst increased with increasing temperature, space velocity, and water/model tar ratio, whereas the former catalyst exhibited the opposite trends, except with respect to temperature. Because of the formation of a Ce−ZrO 2 solid solution, the latter catalyst showed higher stability. During cycling tests, the deactivation of 2%NiO/1%CeO 2 −Al 2 O 3 was observed in the seventh reaction-regeneration cycle. Nickel aggregation, observed on the surface of the catalyst by XRD analysis, may account for the deactivation. Dust deposition on the catalyst surface had a significant influence on tar modification, and the interaction mechanism between dust deposition and coke formation was clarified. The electron probe microanalysis results showed that SiO 2 tends to promote carbon deposition, whereas MgO and Fe 2 O 3 components have a negative influence on carbon deposition. This study can serve as a reliable reference for the practical development and modification of purification processes for coal pyrolysis volatiles.

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The introduction of carbon nanotubes (CNTs) in the preparation of nano-lead oxide (PbO) can effectively solve the problem of easy agglomeration of nano-lead oxide. This study used concentrated nitric acid and concentrated sulfuric acid mixed acid (volume ratio 1:3) to oxidize carbon nanotubes at 90 °C temperature for 0.5 h. Using and the oxidized CNTs as carriers, Pb(OAc)2 · 3H2O as precursor, concentrated ammonia as a precipitator, PbO/CNTs complexes were prepared by chemical precipitation. Lead content of PbO/CNTs complex, determined by Complexometry, was 59.80 %(wt%), XRD and XPS characterizations revealed that the catalyst components of the prepared complex were mainly nano-sized PbO, And a small amount of lead, SEM and EDX characterization revealed PbO with the particle size between 20 m-200 nm had been successfully Loaded onto the CNTs surface, TEM show that the PbO and CNTS retained the original lattice, a spot of lead oxide was found inside the tubes. The thermal decomposition effect of PbO/CNTs on AP, RDX, HMX was evaluated by DSC, and the catalytic effect on AP and RDX was found to be obvious.