共查询到19条相似文献,搜索用时 93 毫秒
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考察了碳五烷烃的热裂解和催化裂解反应性能,发现正戊烷和异戊烷的裂解反应产物存在差异;进一步分析了正戊烷和异戊烷的裂解反应机理,以及裂解生成低碳烯烃和甲烷的区别。结果表明,在热裂解条件下,正戊烷的(乙烯+丙烯)选择性高于异戊烷,异戊烷的丁烯和甲烷选择性高于正戊烷;650℃时,正戊烷和异戊烷的热裂解产品中(乙烯+丙烯)、丁烯、甲烷的选择性分别为37.48%、7.23%、6.75%和19.57%、25.16%、9.36%。而在催化裂解条件下,异戊烷的(乙烯+丙烯)、丁烯、甲烷选择性均高于正戊烷;650℃时,正戊烷和异戊烷的催化裂解产品中(乙烯+丙烯)、丁烯、甲烷的选择性分别为37.16%、9.11%、7.80%和47.70%、14.45%、13.79%。此外,发现在高温裂解条件下异构烷烃比正构烷烃容易裂解生成丁烯和甲烷。 相似文献
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碳四烷烃催化裂解制低碳烯烃的研究进展 总被引:11,自引:0,他引:11
论述了碳四烷烃催化裂解制低碳烯烃的催化剂体系、影响因素及催化裂解方式。该催化剂体系包括硅铝酸盐及锆硫酸盐,氧化铝与碱金属或碱土金属的混合物,负载型催化剂等3种类型。其中分子筛(晶体硅铝酸盐)及其改性催化剂是研究开发的主要方向。除操作条件外,稀释剂、引发和抑制剂和裂解反应方式对催化裂解反应均有影响。催化裂解反应机理与催化剂的种类和反应条件相关。对于酸性分子筛催化剂有2种比较公认的机理:正碳离子机理,自由基与正碳离子机理两种形式。研究表明碳四烷烃,特别是正丁烷催化裂解制低碳烯烃具有良好的低碳烯烃收率,收率可达50%以上。 相似文献
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《中国石油和化工标准与质量》2013,(21)
近年来,随着石油工业的快速发展,对低碳烯烃,尤其是丙烯、乙烯的需求越来越大。开发以石油为原料,通过催化裂解的工艺,生产低碳烯烃逐渐成为当今社会生产的趋势。本文结合重油催化裂解制低碳烯烃工艺,对催化裂解催化剂以及我国的重油催化裂解制低碳烯烃技术进行了简要的探究和阐述。 相似文献
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催化裂解多产低碳烯烃研究进展 总被引:1,自引:0,他引:1
本文从市场需求、催化裂解工艺、反应机理及裂解催化剂等几个方面综述了催化裂解多产低碳烯烃的研究进展,指出深入研究催化剂孔性质及酸性质与催化裂解性能之间的关系,设计具有梯级孔道分布,活性中心高度可接近性的新型催化剂,将会对低碳烯烃生产发挥重要的作用。 相似文献
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对以石油路线生产低碳烯烃的催化裂解工艺进行了综述。催化裂解结合了传统蒸汽裂解和流化催化裂化的优势,表现出良好的原料适应性和较高的低碳烯烃产率,针对不同的石油裂解原料已经开展了相应工艺技术的研究。本文总结了目前催化裂解制低碳烯烃技术的研究进展,指出ZSM-5分子筛催化剂、热力学平衡限制和动力学反应条件是催化裂解反应过程中的重要影响因素和研究内容。催化剂研究仍是催化裂解工艺开发的重点,而热力学和动力学是研究反应规律的有效方法,这是今后实现石油烃类定向转化的研究方向。 相似文献
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石脑油催化裂解制低碳烯烃动力学 总被引:1,自引:0,他引:1
根据石脑油催化裂解的反应体系和集总理论,建立6集总动力学模型,采用Levenberg-Marquardt算法求解ZSM-5分子筛催化剂作用下的石脑油催化裂解动力学参数。结果表明,丙烯收率大大高于乙烯收率,丙烯与乙烯的质量比为1.0~2.0,明显高于传统的石脑油水蒸气裂解工艺,各集总的反应活化能均大于100 kJ/mol。通过对模型进行检验,发现模型计算值与实验值之间的误差均小于15%,表明该动力学模型能较好地预测石脑油催化裂解制低碳烯烃反应。 相似文献
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碳四烯烃催化裂解制丙烯的研究 总被引:4,自引:1,他引:4
采用固定床,以1-丁烯为原料,考察了ZSM-5分子筛催化剂上反应温度对催化裂解产物的影响。实验结果表明,随反应温度的升高,乙烯产率和丙烯产率均增大,620℃时分别为15.40%和33.80%。催化裂解副产重组分中,液相产物接近90%是苯、甲苯、C8芳烃和C9芳烃。C5^=和C6产率均随反应温度升高而降低,C5^=产率下降明显,650℃时仅为2.3%。 相似文献
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R. Le Van Mao N.-T. Vu N. Al-Yassir N. François J. Monnier 《Topics in Catalysis》2006,37(2-4):107-112
The thermocatalytic cracking (TCC) process, which can selectively produce light olefins (mostly, ethylene and propylene for
the petrochemical industry) and transportation fuels (gasoline and diesel fuel), combines the effects of thermal and catalytic
cracking reactions. The TCC catalysts consist mainly of mixed metal oxides supported on a high-surface area – thermally stabilized
alumina. The best TCC catalyst formulation includes a co-catalyst, which provides the main catalyst component with active
hydrogen species formed from hydrogen and other hydrocarbons, particularly methane, produced mainly by thermal cracking. The
interparticular interactions of these hydrogen spilt-over species can occur because these species can be easily transferred
from one particle to the other through the newly formed pore connections 相似文献
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Enhancing the Production of Light Olefins by Catalytic Cracking of FCC Naphtha over Mesoporous ZSM-5 Catalyst 总被引:2,自引:0,他引:2
M. A. Bari Siddiqui A. M. Aitani M. R. Saeed S. Al-Khattaf 《Topics in Catalysis》2010,53(19-20):1387-1393
The enhanced production of light olefins from the catalytic cracking of FCC naphtha was investigated over a mesoporous ZSM-5 (Meso-Z) catalyst. The effects of acidity and pore structure on conversion, yields and selectivity to light olefins were studied in microactivity test (MAT) unit at 600 °C and different catalyst-to-naphtha (C/N) ratios. The catalytic performance of Meso-Z catalyst was compared with three conventional ZSM-5 catalysts having different SiO2/Al2O3 (Si/Al) ratios of 22 (Z-22), 27 (Z-27) and 150 (Z-150). The yields of propylene (16 wt%) and ethylene (10 wt%) were significantly higher for Meso-Z compared with the conventional ZSM-5 catalysts. Almost 90% of the olefins in the FCC naphtha feed were converted to lighter olefins, mostly propylene. The aromatics fraction in cracked naphtha almost doubled in all catalysts indicating some level of aromatization activity. The enhanced production of light olefins for Meso-Z is attributed to its small crystals that suppressed secondary and hydrogen transfer reactions and to its mesopores that offered easier transport and access to active sites. 相似文献
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Catalytic Cracking of Heavy Olefins into Propylene, Ethylene and Other Light Olefins 总被引:1,自引:0,他引:1
Hybrid catalysts developed for the thermo-catalytic cracking of liquid hydrocarbons were found to be capable of cracking C4 + olefins into light olefins with very high combined yields of product ethylene and propylene (more than 60 wt%) and C2–C4 olefins (more than 80 wt%) at 610–640 °C, and also with a propylene/ethylene weight ratio being much higher than 2.4. The olefins tested were heavier than butenes such as 1-hexene, C10 + linear alpha-olefins (LAO) or a mixture of LAO. The hydrogen spillover effect promoted by the Ni bearing co-catalyst, contributed to significantly enhancing the product yield of light olefins and the on-stream stability of the hybrid catalyst. 相似文献
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