| Methlymine consists of MMA, DMA, TMA which are major industrial chemical intermediates. They are used in such areas as solvent production, surtactant, water treatment, pesticide production and medicine raw material. Thermodynamics favors the production of TMA while the largest worldwide demand is for DMA. This has led to major research efforts in the design of new, selective catalysts. The domestic scholars are all value the study of structure and mechanic of catalysts while less in the study of preparation condition, kinetics and industry application. So, there are less catalysts fit the genuine industry and the achievements are far less than the aborad's. what's more, the raw material major in synthesis mordenite while the study of catalysts choosing, preparation and the variation of catalysis performance after adding in binder as the nature mordenite the raw material is less.So, auther do some study of nature mordenite catalysts base on shape-selective theory. The main contents as follow:1) Their phisical-chemical properties were characterized by chemical analysis, XRD, ammonia absorber techniques. Combine the catalysis performance and the data of phisical-chemical properties, the style and constitute of zeolite is confirmed. It shows that the mordenite is the optimal raw material and the constitute need above 75%. Zhejiang-1 is the optimal raw material of synthesis methlymine.2) Confirmed the optimal binder and the optimal proportion. The type of acids and the concentration are confirmed through NHs-TPD, chemical analysis and catalysis performance which is chlorhytric acid and 0.5~2.0mol/L.The The optimal condition of pertreatment is confirmed through orthogonal design which are concentration 2mol/L, temperature 80℃, time 0.5h, second 4times.3) Variations of the modified mordenite by different ions are researched, it shows that the self-made catalysts have a high dimethylamine selectivity than others. Amond them, NaHM is the best, whose the conversion of methanol on a carbon basis is 93.9% and the selectivity to dimethylamine is 38.5% at 673K wherein the single pass yield.4) The preparation condition and route are decided, temperature of roast is confirmed through the XRD and catalysis performance; the results show that the optimal temperature of roast is 450癈, the roasted between the ion exchange is unnecessary. The catalyst of roasted after compacting has high activity and selectivity.5) The influence of reaction temperature, ratio of NH3/CH3OH (N/C) and liquid hourly space velocity (LHSV) of methanol has been considered. The optimal methodology condition is confirmed through orthogonal design which are T=390℃, LHSV=1.93h-1, N/C=1.8. The influence of recycle pass yield has also been considered which shows that it made the selectivity of DMA increased and the condition milder. The optimal feed composition is: NH3 40.0%, MMA 15.3%,CH3OH 44.7%. The stability of NaHM is researched and the results shows that the main reason of deactivation of NaHM is carbon deposit, fresh catalyst has good stability.6) Compared the self-made catalysts to A-6 and synthesis mordenite. It shows that self-made catalyst NaHM has more higher dimethylamine selectivity than others.7) The reasons of variations of the modified mordenite by different ions are analysis through NHs-TPD, chemical analysis and distribution of pore size. It shows that strong acidity avails to the selectivity of DMA, while moderation acidity avails to the activity. As the intension of acidity is equal, the number of acidity is the main factor to methylamine synthesis. Ions-modified made the orifice of mordenite contracted, so the selectivity of DMA improved.
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