Enhanced stability and propylene yield in methanol to light olefins conversion over nanostructured SAPO‐34/ZSM‐5 composite with various SAPO‐loadings

2018 ◽  
Vol 14 (1) ◽  
pp. e2274 ◽  
Author(s):  
Bahman Mohammadkhani ◽  
Mohammad Haghighi ◽  
Erfan Aghaei
Keyword(s):  
Light Olefins ◽  
Propylene Yield ◽  
Enhanced Stability

Experimental Design-Assisted Investigation of Light Olefins Production Over Ceria-Altered HZSM-5 Catalysts by Naphtha Catalytic Steam Cracking

2016 ◽  
Vol 14 (5) ◽  
pp. 1069-1080 ◽  
Author(s):  
Amirhossein Shahbazi Kootenaei ◽  
Sarah Maghsoodi ◽  
Ali Zeinali Varzaneh
Keyword(s):  
Experimental Design ◽  
Reaction Temperature ◽  
Catalytic Performance ◽  
Light Olefins ◽  
Bet Specific Surface Area ◽  
Steam Cracking ◽  
Xrd Patterns ◽  
Propylene Yield ◽  
Propylene Production ◽  
Central Composite

Abstract In this contribution, the effects of ceria loading, Si/Al ratio, and reaction temperature on the catalytic performance of HZSM-5 catalysts for production of ethylene and propylene from light naphtha were investigated. The elaborated catalysts were characterized by XRD, FTIR, SEM, and BET specific surface area. The acquired results demonstrated that HZSM-5 structure was preserved after ceria addition. XRD patterns exhibited a crystallinity degradation of HZSM-5 samples by aluminum addition. Box-Behnken experimental design was utilized with central composite design for investigation of parameters such as reaction temperature (600–700 °C), cerium loading (2–14 wt%), and Si/Al ratio (25–125) in ethylene and propylene production. Analysis of variance (ANOVA) indicated the significance of the studied parameters and the corresponding interactions. The results exhibited that the highest ethylene yield was at the highest reaction temperature, the highest cerium loading, and the lowest Si/Al ratio. The superior propylene yield was attained at the highest Si/Al ratio whereas an optimum can be found for reaction temperature and cerium loading.

Preparation of Phosphorus Modified HZSM-5 Zeolite Catalysts and their Catalytic Performances of Methanol to Olefins

2014 ◽  
Vol 875-877 ◽  
pp. 295-299
Author(s):  
Shu Xun Tian ◽  
Sheng Fu Ji ◽  
Qi Sun
Keyword(s):  
Phosphorus Content ◽  
Strong Acid ◽  
Weight Percent ◽  
Acid Sites ◽  
Zeolite Catalysts ◽  
Light Olefins ◽  
Microporous Structure ◽  
Phosphorous Content ◽  
Propylene Yield ◽  
Strong Acid Sites

To improve the selectivity of light olefins, Phosphorous modified ZSM-5 zeolites catalysts with different phosphorous content were prepared by impregnation and were used in the conversion of methanol to olefins. The properties of acidity and microporous structure of the phosphorous modified ZSM-5 zeolites were investigated by XRD, N2-adsorption and desorption, and NH3-TPD. The highest propylene yield (50.82%) was observed over the H-ZSM-5 modified with the phosphorus content at 9% (weight percent). The selectivity of propylene depended strongly on the phosphorus content in the zeolites; The enhancement of propylene selectivity with increasing phosphorous content was attributed to reduction of strong acid sites on the H-ZSM-5. Modification of the ZSM-5 zeolites with phosphorous also changes the microporous structure.

Structural/Texture Evolution During Facile Substitution of Ni into ZSM-5 Nanostructure vs. its Impregnation Dispersion Used in Selective Transformation of Methanol to Ethylene and Propylene

2020 ◽  
Vol 23 ◽  
Author(s):  
Parisa Sadeghpour ◽  
Mohammad Haghighi ◽  
Mehrdad Esmaeili
Keyword(s):  
High Temperature ◽  
Physicochemical Properties ◽  
Active Sites ◽  
Catalytic Performance ◽  
Fixed Bed Reactor ◽  
Light Olefins ◽  
Isomorphous Substitution ◽  
Impregnation Method ◽  
Hydrothermal Temperature ◽  
X Ray

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.

Efficient Production of Light Olefin Based on Methanol Dehydration: Simulation and Design Improvement

2020 ◽  
Vol 23 ◽  
Author(s):  
S. Majid Abdoli ◽  
Mahsa Kianinia
Keyword(s):  
Dimethyl Ether ◽  
Flow Reactor ◽  
New Technology ◽  
Plug Flow ◽  
Light Olefins ◽  
Efficient Production ◽  
Actual Process ◽  
Light Olefin ◽  
Aspen Hysys ◽  
Improved Design

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

Life Time Improvement of Hierarchically Structured SAPO-34 Nanocatalyst in MTO Reaction via Applying Clinoptilolite, Investigating of Composite Design via RSM

2020 ◽  
Vol 23 ◽  
Author(s):  
Reza Yazdanpanah ◽  
Eshagh Moradiyan ◽  
Rouein Halladj ◽  
Sima Askari
Keyword(s):  
Surface Area ◽  
Natural Zeolite ◽  
Coke Formation ◽  
Life Time ◽  
Weight Percent ◽  
Light Olefins ◽  
Bet Surface Area ◽  
Relative Crystallinity ◽  
Mto Reaction ◽  
The Common

Aim and Objective: The research focuses on recent progress in the production of light olefins. Hence, the common catalyst of the reaction (SAPO-34) deactivates quickly because of coke formation, we reorganized the mechanism combining SAPO-34 with a natural zeolite in order to delay the deactivation time. Materials and Methods: The synthesis of nanocomposite catalyst was conducted hydrothermally using experimental design. Firstly, Clinoptilolite was modified using nitric acid in order to achieve nano scaled material. Then, the initial gel of the SAPO-34 was prepared using DEA, aluminum isopropoxide, phosphoric acid and TEOS as the organic template, sources of Aluminum, Phosphor, and Silicate, respectively. Finally, the modified zeolite was combined with SAPO-34's gel. Results: 20 different catalysts due to D-Optimal design were synthesized and the nanocomposite with 50 weight percent of SAPO-34, 4 hours Crystallization and early Clinoptilolite precipitation showed the highest relative crystallinity, partly high BET surface area and hierarchical structure. Conclusion: Different analysis illustrated the existence of both components. The most important property alteration of nanocomposite was the increment of pore mean diameters and reduction in pore volumes in comparison with free SAPO-34. Due to low price of Clinoptilolite, the new catalyst develops the economy of the process. Using this composite, according to formation of multi-sized pores located hierarchically on the surface of the catalyst and increased surface area, significant amounts of Ethylene and Propylene, in comparison with free SAPO-34, were produced, as well as deactivation time that was improved.

A Review on Biological Properties and Synthetic Methodologies of the Diarylpentadienones

2020 ◽  
Vol 20 ◽  
Author(s):  
Maryam Aisyah Abdullah ◽  
Siti Munirah Mohd Faudzi ◽  
Nadiah Mad Nasir
Keyword(s):  
Biological Properties ◽  
Review Article ◽  
High Potential ◽  
One Pot ◽  
One Pot Synthesis ◽  
Structure Activity ◽  
Synthetic Methodologies ◽  
Relationship Of ◽  
Effective Drugs ◽  
Enhanced Stability

Abstract:: Medicinal chemists have continuously shown interest in new curcuminoid derivatives, the diarylpentadienones, owing to their enhanced stability feature and easy preparation using a one-pot synthesis. Thus far, methods such as Claisen-Schmidt condensation and Julia-Kocienski olefination have been utilised for the synthesis of these compounds. Diarylpentadienones possess a high potential as a chemical source for designing and developing new and effective drugs for the treatment of diseases, including inflammation, cancer, and malaria. In brief, this review article focuses on the broad pharmacological applications and the summary of the structure-activity relationship of molecules which can be employed to further explore the structure of diarylpentadienone. The current methodological developments towards the synthesis of diarylpentadienones are also discussed.

Improving the Efficacy of Anticancer Drugs via Encapsulation and Acoustic Release

2018 ◽  
Vol 18 (10) ◽  
pp. 857-880 ◽  
Author(s):  
Salma E. Ahmed ◽  
Nahid Awad ◽  
Vinod Paul ◽  
Hesham G. Moussa ◽  
Ghaleb A. Husseini
Keyword(s):  
Drug Delivery ◽  
Drug Release ◽  
Drug Delivery Systems ◽  
Delivery Systems ◽  
Special Focus ◽  
Nano Drug Delivery ◽  
Medical Researchers ◽  
History Of ◽  
Overall Performance ◽  
Enhanced Stability

Conventional chemotherapeutics lack the specificity and controllability, thus may poison healthy cells while attempting to kill cancerous ones. Newly developed nano-drug delivery systems have shown promise in delivering anti-tumor agents with enhanced stability, durability and overall performance; especially when used along with targeting and triggering techniques. This work traces back the history of chemotherapy, addressing the main challenges that have encouraged the medical researchers to seek a sanctuary in nanotechnological-based drug delivery systems that are grafted with appropriate targeting techniques and drug release mechanisms. A special focus will be directed to acoustically triggered liposomes encapsulating doxorubicin.

Nano-Structured Ceramic Oxide Catalyst for Syn Gas Conversion to Light Olefins

2012 ◽  
Vol 1 (1) ◽  
pp. 24-31
Author(s):  
Syed Tajammul Hussain ◽  
Nisar Ahmad ◽  
Bakhtiar Muhammad
Keyword(s):  
Oxide Catalyst ◽  
Light Olefins ◽  
Ceramic Oxide ◽  
Gas Conversion
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