共查询到20条相似文献,搜索用时 93 毫秒
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采用共沉淀法制备了Ni/Al2O3加氢催化剂,在制备过程中引入交流电磁场对催化剂做强化制备,通过BET、SEM、XRD和TPR等方法对催化剂做表征,并将该催化剂应用于脂肪酸加氢反应中,考察了磁场强度对催化剂结构及加氢性能的影响。结果表明,制备过程中引入电磁场能够有效降低催化剂颗粒的团聚,增大催化剂的比表面积和平均孔径,提高催化剂的脂肪酸加氢活性。随着磁场强度的增强催化剂还原温度逐渐升高,结构稳定性增强,有效延长了催化剂的使用寿命。 相似文献
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煤快速热解/循环流化床燃烧/催化反应器耦合分级转化工艺易于操作维护,经济效益显著,是实现煤炭资源清洁、高效利用的有效途径之一。但由于煤快速热解工艺产生的焦油油质偏重、污染元素含量较高,造成催化剂频繁失活及再生,因此制备了一种廉价高效的非再生性催化剂。在固定床催化反应装置上,以低温煤焦油为原料,以天然白云石为研究对象,考察催化剂煅烧温度及改性方式对煤焦油催化裂解特性的影响。在催化剂最佳制备条件下制备了1%Ni/2%Fe-白云石催化剂,考察了反应温度对煤焦油催化裂解的影响。结果表明,随煅烧温度升高,促进白云石主要组分CaCO3和MgCO3转化为CaO和MgO活性物质,天然白云石催化剂活性逐渐升高后趋于稳定,最佳煅烧温度为750℃;单独引入Fe后并未促进焦油裂解,同时引入Ni和Fe,明显改善了天然白云石催化剂的催化活性,最佳改性方式为1%Ni/2%Fe-白云石;助剂Fe的引入保护了活性组分Ni的硫中毒失活,同时引入Ni和Fe缓解了催化剂的烧结现象,且Fe作为助剂可减缓催化过程中积碳的产生,Ni改性后白云石催化剂促进了脂肪族化合物及含硫化合物的裂解,... 相似文献
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Nan Jiang Guohui Yang Xiongfu Zhang Lei Wang Chunyan Shi Noritatsu Tsubaki 《Catalysis communications》2011,12(11):951-954
A well-designed zeolite capsule catalyst with a Core (Fe/SiO2)-Shell (Silicalite-1) structure was successfully prepared by zeolite seeding and then zeolite shell growing via secondary hydrothermal method. The characterization on this zeolite capsule catalyst indicated that it had a compact, defect-free zeolite shell enwrapping core catalyst tightly. The application of this zeolite capsule catalyst was the direct synthesis of light alkenes from syngas via Fischer–Tropsch synthesis (FTS) reaction. This zeolite capsule catalyst exhibited excellent abilities compared with the traditional FTS catalyst, both on the controlled synthesis of the desirable light alkenes and the suppressing formation of the undesired long-chain hydrocarbons. 相似文献
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实验考察了醋酸胶溶剂对Hp分子筛催化剂成型强度的影响,并以丙烯和苯合成异丙苯为模型反应,分别以气-液半连续和液-液连续操作两种方式,实验评价催化剂的性能。结果表明:催化剂强度随成型过程中醋酸用量的增加呈现先增大后减小的趋势,最高催化剂强度对应的醋酸用量为6%。随着醋酸用量增加,催化剂活性略有增加,对异丙苯选择性影响不大,但催化剂稳定性却降低。 相似文献
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芳烃精制脱烯烃分子筛催化剂的研究 总被引:1,自引:0,他引:1
本研究以铝胶、硅铝胶及钛铝胶为粘合剂,以HY分子筛为主要活性组分制备了芳烃脱烯烃分子筛催化剂.采用NH3-TPD、BET、TG和活性评价等方法对催化剂的酸性、脱烯烃活性、失活原因及再生性能进行了研究.结果表明,含有不同粘合剂的HY分子筛催化剂的脱烯烃活性均明显高于工业使用的NC-01颗粒白土催化剂,分子筛催化剂表面具有较多的弱酸中心是其性能良好的重要原因.积碳是分子筛催化剂表面失活的主要原因,经焙烧再生处理后分子筛催化剂仍具有较好的脱烯烃性能.经823 K焙烧的硅铝胶质量分数为20%的分子筛催化剂具有较佳的反应性能. 相似文献
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In this study, Y zeolite with different particle sizes was synthesized with fines of Fluid Catalytic Cracking (FCC) spent
catalyst. The effect of particle size on physicochemical properties of zeolite was systematically investigated. The results
showed that zeolites synthesized via in situ crystallization technique exhibited large surface area, high relative crystallinity
and high thermal stability. With a decrease of particle size of zeolite, both total acid density and B acid sites increased
while acid L sites decreased. The cracking activity for heavy oil and coke resistance of ultra-fine zeolite catalysts were
enhanced. Of note is that the desulfurization capability of superfine zeolite catalyst was found to be much higher than that
of industrial catalyst. 相似文献
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改性MOY分子筛在降烯烃FCC催化剂中的应用 总被引:4,自引:1,他引:4
介绍了改性MOY分子筛性能和含MOY复合分子筛降低汽油烯烃含量催化剂的开发及应用。结果表明,MOY分子筛具有良好的氢转移选择性,是降烯烃催化剂较为理想的主活性组分。含MOY复合分子筛的FCC催化剂能有效地使FCC汽油中烯烃体积分数降低10%~12%,适用于生产优级清洁汽油。 相似文献
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The hydrogenation of acetophenone and its derivatives was studied using several supported Ni catalysts. Ni supported on zeolite Y catalyst offered the best hydrogenation activity. However, the activity of this catalyst decreases significantly on recycle and the extent of deactivation differs with respect to the substrate investigated. It is shown in this paper that a bimetallic Ni-Pt catalyst gives improved stability on recycle for hydrogenation of acetophenone and its derivatives. The role of zeolite Y support and a strong synergistic effect in a bimetallic Ni-Pt catalyst has been discussed. 相似文献
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沸石分子筛催化合成异丙苯工艺研究 总被引:3,自引:0,他引:3
介绍了沸石分子筛催化合成异丙苯工艺技术在吉化染料厂原苯酚丙酮车间(现为中国石油吉林石化公司双苯厂)异丙苯单元的工业实验情况。结果表明,采用沸石分子筛催化剂生产异丙苯,与固体磷酸催化剂相比,具有收率高、产品质量好、操作费用低、无腐蚀等优点。沸石分子筛催化剂及其工艺用于吉化股份有限公司染料厂原异丙苯单元的技术改造是完全可行的。 相似文献
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Hao Xu Chi Lei Qinming Wu Qiuyan Zhu Xiangju Meng Daniel Dai Stefan Maurer Andrei-Nicolae Parvulescu Ulrich M ller Fengshou Xiao 《Frontiers of Chemical Science and Engineering》2020,14(2):267
SSZ-39 zeolite with AEI framework structure is a good catalyst candidate for the methanol-to-olefins (MTO) reaction. However, the diffusion limitation and coke formation often results in fast deactivation of the SSZ-39 zeolite catalyst. One solution for this challenge is to introduce mesoporosity in the SSZ-39 zeolite. Herein, we report the synthesis of mesoporous SSZ-39 zeolite using an organosilane surfactant, N,N-dimethyl-N-(3-(trimethoxysilyl)propyl)octan-1-aminium chloride, as a mesopore template and N,N-dimethyl-cis-2,6-dimethylpiperidinium as a micropore template. The obtained zeolites were characterized by X-ray diffraction, N2 sorption, scanning electron microscopy, temperature programmed desorption of ammonia, and magic angle spinning nuclear magnetic resonance of 27Al. The results show that the mesoporous SSZ-39 zeolite has high crystallinity, meso/microporosity, high surface area, cuboid morphology, and abundant acidic sites. More importantly, this mesoporous SSZ-39 zeolite exhibits enhanced catalyst lifetime in the MTO reaction due to the presence of mesoporosity for fast mass transfer, compared with a conventional SSZ-39 zeolite without mesoporosity. 相似文献
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催化裂化轻汽油在ZSM-5分子筛催化剂上裂化反应的研究 总被引:2,自引:0,他引:2
以ZSM-5分子筛为催化剂,在小型固定床反应器上,进行了催化裂化轻汽油的裂化反应。考察了反应温度和空速对催化裂化轻汽油裂化反应气液相收率和产品分布的影响。实验结果表明,ZSM-5分子筛催化剂具有较强的裂化活性和氢转移活性。在保证裂化转化率的条件下,提高反应温度和空速可以抑制催化剂上氢转移反应的发生。以ZSM-5分子筛为催化剂上的催化裂化反应中,温度、空速是影响转化率和选择性的重要因素,因此可以通过改变温度、空速来提高目的产物的选择性。但是,单纯依靠改善反应条件,不能使目的产物的收率和选择性达到理想的程度,还必须对催化剂进行改性。ZSM-5分子筛催化剂上催化裂化反应的研究为ZSM-5分子筛催化剂的进一步改性,及ZSM-5分子筛催化剂在轻汽油催化裂解和汽油改质方面的进一步应用提供了试验依据。 相似文献