共查询到18条相似文献,搜索用时 46 毫秒
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采用程序升温脱附 (TPD)方法 ,对液相合成甲醇和甲酸甲酯铜基催化剂吸附氢气、一氧化碳、甲醇和甲酸甲酯后的脱附行为进行了考察 ,采用程序升温还原 (TPR)方法 ,对催化剂在氢气气氛中的还原行为进行了考察。结果表明 ,催化活性高的催化剂 ,其氢气的脱附温度一般也较低。氢气和一氧化碳的吸附强度对于合成反应没有显著的影响。脱附活化能计算表明具有较小甲酸甲酯脱附活化能的催化剂 ,其活性较高。使用过的和经过还原的催化剂 ,TPR峰向高温段移动。铜的价态在 +1价附近的催化剂活性较高 相似文献
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Cu-Ni/ZnO双金属催化剂上顺酐加氢反应的研究 总被引:1,自引:0,他引:1
用共沉淀法制备了 Cu Ni/ Zn O 双金属催化剂, 用 T P R 和 X R D 等方法并结 合顺酐加氢反应对催化剂中组分间的相互作用进行了研究。结果表明, Zn O 对 Cu O 具有分散作用, 能促进 Cu O 的还原; 而与 Ni O 有强相互作用, 使后者较难还原, Cu 与 Ni 也存在相互作用。催化剂在还原过程中存在诱导期和还原期, 首先 H2 缓慢还原出少量 Cu , Cu 又解离吸附 H2 为活泼 [ H] , [ H] 能较快地还原 Ni O 和 Cu O, 并形成 Cu38 Ni 合金。 相似文献
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顺酐直接加氢制备γ-丁内酯工艺研究 总被引:5,自引:1,他引:5
在固定床反应器中,以顺丁烯二酸酐为原料,直接加氢制得γ-丁内酯。考察了反应温度、反应压力、顺丁烯二酸酐液态空速、氢酐摩尔比等条件对反应的影响,确定了最佳反应条件:反应温度265℃左右,压力0 4~0 8MPa,氢酐摩尔比250/1,液态空速不大于0 24h-1。提出了催化剂的再生方法,并进行了稳定性实验。结果表明,该催化剂稳定性良好。 相似文献
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1,4-丁二醇(BDO)的工业生产方法主要有Reppe法、顺酐法、丁二烯乙酰氧化法和丙烯醛法,其中,顺酐法具有能耗少、设备投资少和工艺简单等优势,符合节能减排降碳的目标要求。介绍了顺酐酯化加氢和顺酐直接加氢制备BDO两种工艺,综述了制备BDO工艺所用主要催化剂的研究进展,并提出了未来顺酐法制备BDO可能的研究方向。 相似文献
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采用釜式反应器研究了负载型钯催化剂对于顺酐及其衍生物(马来酸、琥珀酸以及琥珀酸酐)加氢生成γ-丁内酯的催化性能以及分子筛的添加效果。结果表明,以活性炭为载体的钯催化剂具有良好的γ-丁内酯生成活性,添加碱金属型分子地顺酐及其衍生物加氢生成γ-丁内酯有促进效果。考察了溶剂以及反应温度、氢气压力和反应时间对γ-丁内酯收率的影响。 相似文献
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Hydrogenation of maleic anhydride (MA) to succinic anhydride (SA) over Ni-Pd bimetallic catalysts prepared by impregnation method has been studied at different Pd contents, pressures and temperatures. Catalytic activity was greatly influenced by the Pd content, pressure and temperature. Use of 5wt%Ni-0.02wt%Pd/clay catalyst, the 100% conversion for MA and 100% selectivity for SA were obtained for MA hydrogenation at normal pressure. The catalysts were characterized by an array of techniques, including X-ray diffraction (XRD) and H2 temperature-programmed reduction (TPR). XRD and TPR studies showed that nickel was present as Ni2+ species on the support, and that there was no elemental nickel (Ni0) and Ni2O3 in the unreduced samples. XRD and TPR also showed that Pd was as amorphous existence on the catalysts. 相似文献
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介绍的顺酐催化剂好的装填方法可使反应收率维持在新催化剂的水平,使新催化剂使用量节约一半。该方法已用于生产中。结果表明,方法可行,有效。并用动力学理论进行了分析,认为试验结果合理。 相似文献
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Cr-promoted vanadium phosphate (VPO) catalyst was synthesized by mechanotreating VOHPO4·0.5H2O in cyclohexane for 2 hr using a high energy planetary ball miller followed by calcination in a flow of n-butane/air mixture at 673 K. The physico-chemical properties of the sample were investigated by several characterization techniques such as BET, XRD, redox titration, SEM, and TPR. The data were compared to the unmilled material. BET surface area measurement of the milled catalyst showed that it possesses higher surface area (13.2 m2 g-1) compared to the unmilled catalyst (6.4 m2 g-1). Milling also caused a slight increment in the average oxidation state of vanadium as well as the percentage of V5+ oxidation state. XRD pattern of the milled material revealed that the major diffraction peaks were broadened thus indicating a reduction of particle size. SEM micrographs showed the lost in the blossom morphology and the formation of layer packages, with more circular particles in the milled catalyst. The amount of active lattice oxygen species being removed from V4+-O- pairs increased significantly for mechanochemical treated Cr-doped VPO catalyst leads to the enhancement of the catalytic activity for n-butane oxidation to maleic anhydride. 相似文献
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Abstract Cr-promoted vanadium phosphate (VPO) catalyst was synthesized by mechanotreating VOHPO4·0.5H2O in cyclohexane for 2 hr using a high energy planetary ball miller followed by calcination in a flow of n-butane/air mixture at 673 K. The physico-chemical properties of the sample were investigated by several characterization techniques such as BET, XRD, redox titration, SEM, and TPR. The data were compared to the unmilled material. BET surface area measurement of the milled catalyst showed that it possesses higher surface area (13.2 m2 g?1) compared to the unmilled catalyst (6.4 m2 g?1). Milling also caused a slight increment in the average oxidation state of vanadium as well as the percentage of V5+ oxidation state. XRD pattern of the milled material revealed that the major diffraction peaks were broadened thus indicating a reduction of particle size. SEM micrographs showed the lost in the blossom morphology and the formation of layer packages, with more circular particles in the milled catalyst. The amount of active lattice oxygen species being removed from V4+-O? pairs increased significantly for mechanochemical treated Cr-doped VPO catalyst leads to the enhancement of the catalytic activity for n-butane oxidation to maleic anhydride. 相似文献
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梁轶 《精细石油化工进展》2001,2(7):41-45,52
介绍了顺酐生产现状,对苯法和正丁烷法顺酐生产路线进行了技术分析,重点介绍正丁烷法生产顺酐的生产工艺,包括ALMA工艺、BP工艺、SD工艺及CONSER-PANTOCHIM工艺。详细介绍了国内外顺酐消费及市场,指出正丁烷法生产顺酐的关键是催化剂的研制,提出生产顺酐的建议。 相似文献
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顺酐生产技术进展及用途 总被引:1,自引:0,他引:1
顺酐 (MA)是具有许多用途的单体和中间体 ,主要用于生产不饱和聚酯树脂 (UPR)和 1,4 -丁二醇 (BDO) ,还可用来生产增塑剂、表面涂料、农用化学品、润滑剂、苹果酸和富马酸等[1] 。1999年全球MA生产能力达 1 37Mt[2 ] ,1998~ 2 0 0 3年全球MA需求年均增长为 5 1% ,到 2 0 0 3年全球MA需求量达到 1 16Mt[3] 。 1999年我国MA生产能力达 15 0kt ,预测到 2 0 0 5年我国MA需求量为 180kt ,年均增长率为 9 84 %。苯氧化生产MA于 1930年初首次实现工业化 ,1980年以前一直以苯为原料生产MA。但因在苯原料中存在两个… 相似文献