[CoCuMnOx Photocatalyzed Oxidation of Multi-component VOCs and Kinetic Analysis].

Solar energy absorption coating CoCuMnOx was prepared by co-precipitation method and applied to photodegrade multi- component VOCs including toluene, ethyl acetate and acetone under visible light irradiation. The photocatalytic oxidation performance of toluene, ethyl acetate and acetone was analyzed and reaction kinetics of VOCs were investigated synchronously. The research indicated that removal rates of single-component toluene, ethyl acetate and acetone were 57%, 62% and 58% respectively under conditions of 400 mg · m⁻³ initial concentration, 120 mm illumination distance, 1 g/350 cm² dosage of CoCuMnOx and 6 h of irradiation time by 100 W tungsten halogen lamp. Due to the competition among different VOCs, removal efficiencies in three-component mixture were reduced by 5%-26% as compared with single VOC. Degradation processes of single-component VOC and three-component VOCs both fitted pseudo first order reaction kinetics, and kinetic constants of toluene, ethyl acetate and acetone were 0.002, 0.002 8 and 0.002 33 min⁻¹ respectively under single-component condition. Reaction rates of VOCs in three-component mixture were 0.49-0.88 times of single components.

[Microwave In-situ Regeneration of Cu-Mn-Ce/ZSM Catalyst Adsorbed Toluene and Distribution of Bed Temperature].

Microwave in-situ regeneration of Cu-Mn-Ce/ZSM catalyst adsorbed toluene, distribution of fixed bed temperature, adsorption breakthrough curves of the catalyst after several regenerations and characterizations of the catalyst by BET and SEM were investigated in this study. The research indicated that regeneration effect of the catalyst adsorbed was excellent under conditions of microwave power 117 W, air flow 0.5 m3 x h(-1) and catalyst dosage of 800 g. Toluene desorbed was oxidized onto the surface of the catalyst, and the adsorption capacity of the catalyst was recovered simultaneously. Under microwave irradiation, bed temperature decreased slowly from inside to outside in horizontal level, and increased gradually from down to up in vertical level so that the highest temperature reached 250-350 degrees C at the upper sites of the bed. Sintering and agglomeration occurred on the surface of the catalyst in the course of regeneration so that the special surface area and micropore volume of the catalyst were reduced and breakthrough time was shortened, which was verified by six adsorption breakthrough curves and related characteristics of the catalyst. However, the structure of the catalyst was steady after two regenerations, and adsorption breakthrough time was kept at 70 min. The result showed that the changes of surface morphology and pore structure were positively correlated with the distribution of bed temperature.

[Catalytic oxidation of two-component VOCs and kinetic analysis ].

Catalytic oxidations of two-component volatile organic compounds (VOCs) toluene and chlorobenzene were investigated under microwave heating and tube furnace heating, respectively, and reaction kinetics were analyzed in this paper. The research indicated that competitive adsorption between toluene and chlorobenzene reduced their removal efficiencies by 3% -12% as compared to single component. 'Hot spot effect' and 'non-thermal effect' under microwave irradiation obviously enhanced conversion efficiencies of VOCs, especially, the chlorobenzene removal was increased by 31% -38%. Moreover, reaction temperature and energy consumption were both reduced under microwave heating. The dynamic calculations showed that microwave heating decreased the activation energies by 2 146 J. mol-1 and 1 450 J mol-1 for toluene and chlorobenzene, respectively, as compared with tube furnace heating. Meanwhile, microwave heating enhanced the reaction rate constants of chlorobenzene and toluene to about 35 times and 6 times of that of tube furnace heating.