Syngas to light olefins over La doped ZnxAlyOz composite and SAPO-34 hybrid catalysts

Author(s):  
G. Raveendra ◽  
Baorun Ma ◽  
Xiaohui Liu ◽  
Yong Guo ◽  
Yanqin Wang

The direct transformation of syngas to light olefins is a highly attractive route for the synthesis of light olefins. The La doped ZnxAlyOz catalyst was prepared with various precipitating agents,...

2019 ◽  
Vol 139 (9) ◽  
pp. 323-328
Author(s):  
Sho Ojima ◽  
Shigeru Fujimoto ◽  
Akihiro Morohoshi ◽  
Masaaki Ichiki
Keyword(s):  

2015 ◽  
Vol 30 (2) ◽  
pp. 171 ◽  
Author(s):  
CHEN Tao-Tao ◽  
LI Dan ◽  
JING Wen-Heng ◽  
FAN Yi-Qun ◽  
XING Wei-Hong

2019 ◽  
Author(s):  
Timothy Newhouse ◽  
Alexander Schuppe ◽  
Yizhou Zhao ◽  
Yannan Liu

We report the first total synthesis of (+)-granatumine A, a limonoid alkaloid with PTP-1B inhibitory activity, in 10 steps. Over the course of this study, two key methodological advances were made: a cost effective procedure for ketone alpha,beta-dehydrogenation using allyl-Pd catalysis, and a Pd-catalyzed protocol to convert epoxyketones to 1,3-diketones. The central tetrasubstituted pyridine is formed by a convergent Knoevenagel condensation and carbonyl-selective electrocyclization cascade, which was followed by a direct transformation of a 2<i>H</i>-pyran to a pyridine. These studies have led to the structural revision of two members of this family.


2013 ◽  
Vol 28 (4) ◽  
pp. 436-440 ◽  
Author(s):  
Yi-Jun XIE ◽  
Yi-Ping GUO ◽  
Wen DONG ◽  
Bing GUO ◽  
Hua LI ◽  
...  

2012 ◽  
Vol 29 (9) ◽  
pp. 1096
Author(s):  
Jipeng FU ◽  
Xiuyun YANG ◽  
Shanshan ZHANG ◽  
Ying GAO ◽  
Xiuxia GAO ◽  
...  

Author(s):  
Parisa Sadeghpour ◽  
Mohammad Haghighi ◽  
Mehrdad Esmaeili

Aim and Objective: Effect of two different modification methods for introducing Ni into ZSM-5 framework was investigated under high temperature synthesis conditions. The nickel successfully introduced into the MFI structures at different crystallization conditions to enhance the physicochemical properties and catalytic performance. Materials and Methods: A series of impregnated Ni/ZSM-5 and isomorphous substituted NiZSM-5 nanostructure catalysts were prepared hydrothermally at different high temperatures and within short times. X-ray diffraction (XRD), Field emission scanning electron microscopy (FESEM), Energy dispersive X-ray (EDX), Brunner, Emmett and Teller-Barrett, Joyner and Halenda (BET-BJH), Fourier transform infrared (FTIR) and Temperature-programmed desorption of ammonia (TPDNH3) were applied to investigate the physicochemical properties. Results: Although all the catalysts showed pure silica MFI–type nanosheets and coffin-like morphology, using the isomorphous substitution for Ni incorporation into the ZSM-5 framework led to the formation of materials with lower crystallinity, higher pore volume and stronger acidity compared to using impregnation method. Moreover, it was found that raising the hydrothermal temperature increased the crystallinity and enhanced more uniform incorporation of Ni atoms in the crystalline structure of catalysts. TPD-NH3 analysis demonstrated that high crystallization temperature and short crystallization time of NiZSM-5(350-0.5) resulted in fewer weak acid sites and medium acid strength. The MTO catalytic performance was tested in a fixed bed reactor at 460ºC and GHSV=10500 cm3 /gcat.h. A slightly different reaction pathway was proposed for the production of light olefins over impregnated Ni/ZSM-5 catalysts based on the role of NiO species. The enhanced methanol conversion for isomorphous substituted NiZSM-5 catalysts could be related to the most accessible active sites located inside the pores. Conclusion: The impregnated Ni/ZSM-5 catalyst prepared at low hydrothermal temperature showed the best catalytic performance, while the isomorphous substituted NiZSM-5 prepared at high temperature was found to be the active molecular sieve regarding the stability performance.


Author(s):  
S. Majid Abdoli ◽  
Mahsa Kianinia

Background: Ethylene, propylene, and butylene as light olefins are the most important intermediates in the petrochemical industry worldwide. Methanol to olefins (MTO) process is a new technology based on catalytic cracking to produce ethylene and propylene from methanol. Aims and Objective: This study aims to simulate the process of producing ethylene from methanol by using Aspen HYSYS software from the initial design to the improved design. Methods: Ethylene is produced in a two-step reaction. In an equilibrium reactor, the methanol is converted to dimethyl ether by an equilibrium reaction. The conversion of the produced dimethyl ether to ethylene is done in a conversion reactor. Changes have been made to improve the conditions and get closer to the actual process design done in the industry. The plug flow reactor has been replaced by the equilibrium reactor, and the distillation column was employed to separate the dimethyl ether produced from the reactor. Result and Conclusion: The effect of the various parameters on the ethylene production was investigated. Eventually, ethylene is


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