| Vinyl acetate is the important chemical industry material. The activated carbon containing zinc acetate is as catalyst in the acetylene vinyl acetate synthesis, but the catalysts lose their activation because of wrapping zinc acetate by complex organic, blocking the activated carbon pores. The spent catalyst from vinyl acetate synthesis is a typical solid waste resource. In view of the present situation that the spent catalyst for vinyl acetate synthesis with wraps material inside and the separation of zinc with wraps material is difficult. Single research methods and weak theoretical research constrain the utilization and industrialization of spent catalyst. Based on the research results of previous literatures, two novel methods of dealing with the spent catalyst is proposed in this dissertation. Besides, the key technology and related theories are studied. Some meaningful conclusions are obtained.1. The key technology on removal of zinc and regeneration of activated carbonFirst, the thermogravimetric analysis is taken to study the spent catalyst thermal decomposition characteristic and dynamics, main decomposition temperature and the thermal decomposition dynamics model of the material wrapped in the spent catalyst are obtained, the main zero-g period's dynamics model conformed to the first-level chemical reaction and the univariate diffusion control Parabolic principle, the apparent activation energy respectively was 37.4 and 43.1kJ/mol, which has laid the rationale for the microwave pretreatment; the influence of microwave pretreatment temperature and the time on the zinc leaching rate is studied, the addition microwave pretreatment makes the zinc the leaching rate enhance from 42% to 95%, considering about the overall evaluation of zinc leaching rate and the returns-ratio, the optimum microwave pretreatment technological conditions are the pretreatment temperature at 900℃and time of 12min, under this condition, the zinc leaching rate and the returns-ratio respectively is 95.79% and 92.96%. The microwave pretreatment takes good use of the microwave flash heat, the internal heating, which opens the passage way blocked up in the spent catalyst, makes the zinc compound expose in the spent catalyst's surface and realizes the transformation of "covered zinc to uncovered zinc". The separation of zinc and carbon improved the removal rate of zinc.The response surface methodology is taken to study the influences of ammonia density, the extraction time and liquid solid proportion on the zinc leaching rate. On the base of variance analysis, the multiple regressions and the model fitting's foundation, the optimun technological parameter is obtained. The XRD, SEM and the nitrogen adsorption analysis indicated that after leaching in the sample XRD spectrogram, the zinc oxide diffraction peak vanished, only with the obvious C peak (002 and 100) left, after leaching, the sample's surface area increased from 824m2/g to 922m2/g. The SEM shows the more activated carbon passageway.By studying the influences of steams of the ammonia time and the steam current capacity on zinc oxide forerunner body, the optimum technological conditions obtained are:The temperature 92～96℃, steam of ammonia time 120min, steam current capacity 40g/min;The basic zinc carbonate's thermogravimetric analysis indicated that basic zinc carbon thermal decomposition dynamics conforms to the first-level chemical reaction,the thermal decomposition process's average apparent activation energy is 33.9kJ/mol; Afterward with the microwave temperature of 350℃, keeping warm under the 30min condition,the active zinc oxide product up to the first standard (HG/T2572-94) is obtained.Based on the center unitized design response surface methodology (RSM), the reaction mechanism of regenerating activated carbon was investigated along with the optimum proeess parameters and researeh of the carbon's structures. The result indicated that:the influence of technological parameter on iodine value and rate conforms to two factor interactions and the quadratic equation model separately, by analyzing each factors' significance and the correlation, the spent catalyst preparation activated carbon optimization technological conditions is obtained, as following:The temperature of 891℃, time of 90min, steam current capacity of 0.6g/min, there is a good fitting between the predicted value and the actual value. Under the optimum condition with RSM, the regeneration activated carbon's surface area is 1560m2/g, which respectively is 5.76 times and 1.67 times of the spent catalyst and the new coal, however, in the experiment condition (regeneration temperature 1000℃) the surface area of the activated carbon regenerated is only 1255m2/g.The regenerated activated carbon is taken as raw material, the influence of the methylene blue solution concentration and the adsorption time on the saturated adsorptive capacity has been studied, Langmuir and the Freundlich adsorption uniform temperature type are used for the analysis of the adsorption equilibrium data, the adsorption uniform temperature type of methylene blue by regeneration activated carbon could be described by Langmuir isothermal. The second-level dynamics model could describe the adsorption process well. The result indicated that:The regeneration activated carbon adsorption methylene blue's Langmuir saturated adsorptive capacity is 425.53mg/g, higher than generally the commercial activated charcoal saturated adsorptive capacity the literature reported. The plenty of mesopore stuctures (mesopore volume 0.43cm3/g) is useful for diffuse and adsorption of organic molecules adsorbate. The regeneration activated carbon has high surface area and developed mesopore stuctures, and it is suitable to the treatment of the methylene blue dye waste water.2. Fundamental theory on preparation of ZnO/AC compound materials from spent catalystThe spent catalyst is used to prepare the ZnO/AC compound materials for first time in this work, the influence of preparation temperature on the sample structure and the adsorption performance is studied. The nitrogen adsorption, iodine adsorption, XRD, SEM-EDS and FT-IR have been carried out to manifest the sample hole structure and the superficial appearance, which finally indicated that:Under the different temperature, the samples obtained are composed of the activated carbon and ZnO, which forms the ZnO/AC compound. The ZnO crystal grain uniform distributes around the activated carbon and it is six side spiauterite structures. The temperature has great effect on the activated carbon pore structure and the ZnO grain size. Along with temperature's elevation and the zinc acetate's decomposition, the activated carbon passageway is opened, the micropore and semipore increase, the surface area, the total pole volume and the ZnO grain size increase gradually, at 950℃, the sample's surface area may achieve 1193m2/g, while ZnO grain size achieve 35nm. The temperature further elevates to 1000℃, the surface area and the ZnO grain size reduces.The density functional method PBE/Gen and the B3LYP/Gen method are used to study Zn(HCOO)2, Zn(CH3COO)2 and the middle product of Zn-oxo, Zn4O(HCOO)6 and Zn4O(CH3COO)6, which may appear in the decomposition process. Four kinds of compound geometry configurations, the energy characteristic, the electric charge, the front molecular orbit, the infrared spectrum and the thermodynamic property are calculated. The optimization and the energy computation with (0001) crystal face zinc oxide molecular clustering model Zn4O4 are also carried out. The result indicated that:The Zn-oxo compound's stability is higher than its corresponding carboxylate, the regular tetrahedron structure formed by central O2- with periphery four Zn2+ is the entire compound stable key, this kind of regular tetrahedron coordinate conforms to the spiauterite zinc oxide structural feature, therefore it could be regarded as the bulk ZnO forerunner body or the molecular model. The ZnO molecular clustering model's computation indicated that Zn4O4(1010) is stabler than Zn4O4 (0001). The thermodynamic property computation further proved that the zinc acetate decomposition into Zn4O(CH3COO)6 in thermodynamics is feasible. Zn4O(CH3COO)6 decomposes finally as the zinc acetate decomposition process important intermediary product into the zinc oxide, the acetone and the carbon dioxide, responds under the low temperature is enthalpy control process, but under high temperature is entropy control process.In all, the key theoretics and process of two new crafts to convert the spent catalyst into resources were studied in this work. The former uses the microwave heating, which broke the technology bottleneck of the separation of zinc and wraped materials, and may obviously reduce the energy consumption, get high resource utilization, improve work condition and lower the second pollution. The new craft of spent catalyst for the preparation of compound materials provides the new raw material original, meanwhile, by quantum chemistry and molecular mechanics, the microscopic angle discussion of zinc acetate's decomposition reaction process as well as the ZnO crystal's electronic structure characteristic is carried out, which lays the basic theories for the optimization experimental condition and preparation of the high quality multi-purpose compound materials. An effective method for regeneration and comprehensive utilization of valueable wraped materials is provided in this research.
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