| The balance of chlorine and sodium hydrate is a general problem in chlor-alkali industry, In most chlorination of organics, the use ratio of chlorine resource is only 50%, and the environmental pollution is caused directly or indirectly by by-product hydrogen chloride from the chlorination. So, it is worth of converting hydrogen chloride to chlorine for coordinate development of chlor-alkali industry, use of natural resources, environmental protection and increase of the economic benefit of chemical industry. Since 19th century, the catalyst, process and equipment for the technology of oxidation of HCl have been developed widely. So far the perfect industrial technology of oxidation of HCl haven't come out, because of low conversion of HCl, serious corrosion to equipment and high operation cost. In this article, for the industrial chlorination of organics, the by-product HCl from chlorination of toluene was used as raw material and the process of oxidation of HCl into chlorine in a fixed-bed reactor was systematically researched using self-made catalyst. There are two main kinds of catalyst, copper series and chromium series, for the oxidation of HCl. In this article, the catalyst consisting of the active constituent chromium and two promoters was prepared by impregnation in γ-Al2O3 carrier.The result of XRD showed that the active constituent was dispersed uniformly, and it was amorphous crystal on the γ-Al2O3 carrier. According to the analysis of crystal form from XRD, it could be inferred that the catalyst was a complex of oxide of chromium, promoter 1 and the compound formed by promoter 1, promoter 2 and chromium.The results of performance evaluation showed that the catalyst had the highest catalytic activity when the ratio of chromic nitrate to promoter was 1:1.25 and the calcination temperature was 500~550℃. And its catalytic activity had hardly changed after running 150h. Although chromium in the catalyst could be from chromic nitrate, chromic anhydride and potassium dichromate, the catalytic activity of two catalysts from chromic nitrate and chromic anhydride was identical. There was the agglutinative phenomenon on the γ-Al2O3 carrier for the catalyst made from chromic anhydride.There were different distributions of active constitute on carrier for the catalysts made by two different impregnation methods, fractional impregnation and mixing impregnation. Their catalytic activity is almost same for the oxidation of hydrogen chloride. The specific surface area of the carrier had great effect on the catalytic activity. The result for comparison of activity of catalysts from two carriers with different specific surface area showed that the greater specific surface area was corresponding to higher activity.The results of TG showed that the catalyst was stable under 440℃, the weight loss was not obvious. With the thermogravimetric analysis curve, the promoter 1 in the catalyst was converted to the chlorinated compound in the reaction.The by-product HCl from side-chain chlorination of toluene was used as raw gas, and the effect of organic impurity on the progress was studied at the same time. The results showed that a small amount of organic impurity had no obvious influence on catalytic activity, but an organic crystal jammed in the outlet pipe of reactor was discovered, because of formation of some chlorinated compound from depth-type chlorination. The organic component in the raw gas was separated effectively by adsorption with γ-Al2O3, and the adsorbent was regenerated conveniently.The results of oxidation technology showed that the proposal temperature was 360~370℃, the temperature distribution of catalyst bed varied from 360℃ to 420℃. With the increase of temperature, the conversion increased obviously. When the temperature of control point in the reactor was above 370℃, the active constituent was volatilized and catalytic activity was decreased because of the high temperature in the reactor. In allusion to the hot-spot phenomenon in the fixed-bed, some amount of inert material w...
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