Catalytic Cracking of n-Hexane over MeAPOs Molecular Sieves

2011 ◽  
Vol 236-238 ◽  
pp. 1063-1066
Author(s):  
Li Li Feng ◽  
Chong Chen Wang ◽  
Xing Yi Qi
Keyword(s):  
Molecular Sieves ◽  
Catalytic Cracking ◽  
Contact Time ◽  
Hydrothermal Crystallization ◽  
Reaction Conditions ◽  
First Order ◽  
Crystallization Method ◽  
Cracking Performance ◽  
Conversion Level ◽  
Hexane Concentration

Mg-, Zn-, and Cu-substituted aluminophosphate molecular sieves (MeAPO-5 and MeAPO-11) were synthesized by hydrothermal crystallization method. Then-hexane cracking performance over the as-prepared MeAPOs was estimated under different reaction conditions. MeAPO-5 molecular sieves exhibited higher activity for the cracking conversion in the temperature range of 723~823 K than MeAPO-11. The conversion level ofn-hexane over MeAPOs with the same topology had the following order: MgAPOs > ZnAPOs > CuAPOs. The cracking results showed that the conversion level ofn-hexane increased with increasing reaction temperatures and contact time, and that the first order is determined in then-hexane concentration.

Influence of Substituting Al by Mg-Co and Mn-Co on the Properties of AlPO4-5

1992 ◽  
Vol 57 (4) ◽  
pp. 750-755 ◽  
Author(s):  
Liao Changsheng
Keyword(s):  
Catalytic Activity ◽  
Infrared Spectra ◽  
Molecular Sieves ◽  
Molecular Sieve ◽  
Surface Acidity ◽  
Chemical Compositions ◽  
Hydrothermal Crystallization ◽  
X Ray Diffraction ◽  
X Ray ◽  
Crystallization Method

Two kinds of crystalline microporous metal aluminophosphate molecular sieves, magnesium cobalt aluminophosphate (MgCoAPO-5) and manganese cobalt aluminophosphate (MnCoAPO-5), were synthesized by hydrothermal crystallization method in order to improve the surface acidity and catalytic activity of AlPO4-5. The results of X-ray diffraction, infrared spectra and chemical compositions of MgCoAPO-5 and MnCoAPO-5 indicate that Mg-Co or Mn-Co enter the framework of AlPO4-5 molecular sieve without disrupting the microporous framework. However, the results of catalytic studies show that MgCoAPO-5 and MnCoAPO-5 possess much higher surface acidity and catalytic activity than the unmodified AlPO4-5.

Catalytic Cracking Law of Recycle Oil over Equilibrium Catalyst

2013 ◽  
Vol 781-784 ◽  
pp. 223-226
Author(s):  
Yi Bin Liu ◽  
Xue Ding ◽  
Wei Li
Keyword(s):  
Fluidized Bed ◽  
Reaction Temperature ◽  
Catalytic Cracking ◽  
Space Time ◽  
Reaction Conditions ◽  
Product Distributions ◽  
Cracking Performance ◽  
Equilibrium Catalyst

Catalytic cracking experiment of recycle oil was carried out in fixed fluidized bed apparatus. The effects of reaction temperature, catalyst to oil ratio and space time on product distributions were investigated. Low conversion of recycle oil was exhibited due to poor cracking performance, moreover, reaction conditions showed obvious influence on gasoline yield.

scholarly journals A diffusion anisotropy descriptor links morphology effects of H-ZSM-5 zeolites to their catalytic cracking performance

2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Xiaoliang Liu ◽  
Jing Shi ◽  
Guang Yang ◽  
Jian Zhou ◽  
Chuanming Wang ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Catalytic Cracking ◽  
Catalytic Performance ◽  
Zeolite Catalysts ◽  
Time Resolved ◽  
Cracking Performance ◽  
Morphology Effect ◽  
Ft Ir ◽  
The Difference ◽  
Dynamics Simulations

AbstractZeolite morphology is crucial in determining their catalytic activity, selectivity and stability, but quantitative descriptors of such a morphology effect are challenging to define. Here we introduce a descriptor that accounts for the morphology effect in the catalytic performances of H-ZSM-5 zeolite for C4 olefin catalytic cracking. A series of H-ZSM-5 zeolites with similar sheet-like morphology but different c-axis lengths were synthesized. We found that the catalytic activity and stability is improved in samples with longer c-axis. Combining time-resolved in-situ FT-IR spectroscopy with molecular dynamics simulations, we show that the difference in catalytic performance can be attributed to the anisotropy of the intracrystalline diffusive propensity of the olefins in different channels. Our descriptor offers mechanistic insight for the design of highly effective zeolite catalysts for olefin cracking.

scholarly journals Role of Catalyst in Optimizing Fluid Catalytic Cracking Performance During Cracking of H-Oil-Derived Gas Oils

ACS Omega ◽  
2021 ◽  
Author(s):  
Dicho Stratiev ◽  
Ivelina Shishkova ◽  
Mihail Ivanov ◽  
Rosen Dinkov ◽  
Borislav Georgiev ◽  
...  
Keyword(s):  
Catalytic Cracking ◽  
Fluid Catalytic Cracking ◽  
Cracking Performance

Lipase-Catalyzed Acyl-L-Carnitines Synthesis in [Bmim]PF6 Ionic Liquid

2009 ◽  
Vol 5 (1) ◽  
Author(s):  
Jin-qiang Tian ◽  
Qiang Wang ◽  
Zhong-yuan Zhang
Keyword(s):  
Ionic Liquid ◽  
Lipase Activity ◽  
Molecular Sieves ◽  
Reaction Medium ◽  
Molar Ratio ◽  
Reaction Conditions ◽  
Optimal Reaction ◽  
Better Than

In order to significantly improve the biosynthesis of acyl-L-carnitines catalyzed by lipase, there must be an efficient and suitable reaction medium that is not only polar but also hydrophobic. [Bmim]PF6, which satisfies the above two requirements, was applied as the medium. The optimal reaction conditions were: for isovaleryl-L-carnitine, 0.22aW, 200mg molecular sieves, 60ºC, 4:1 of molar ratio (fatty acid:L-carnitine), 150rpm and 60h; for octanoyl-L-carnitine and palmitoyl-L-carnitine, 0.22aW, 250 mg molecular sieves, 5:1 of molar ratio (fatty acid:L-carnitine), 200rpm, 48h, 60ºC (octanoyl-L-carnitine) and 65ºC (palmitoyl-L-carnitine). Their overall yields could reach 59.14%, 90.79% and 98.03%, respectively. The yields of isovaleryl-L-carnitine, octanoyl-L-carnitine and palmitoyl-L-carnitine in [Bmim]PF6 were 16.21%, 73.67% and 44.22 % more than those in acetonitrile, respectively. [Bmim]PF6 as the medium was better than acetonitrile. It could not only enhance the yields of acyl-L-carnitines, but also protect the lipase activity.

Performance assessment of an analcime-C zeolite–ceramic composite membrane by removal of Cr(vi) from aqueous solution

RSC Advances ◽  
2015 ◽  
Vol 5 (9) ◽  
pp. 6246-6254 ◽  
Author(s):  
R. Vinoth Kumar ◽  
Ashim Kumar Basumatary ◽  
Aloke Kumar Ghoshal ◽  
G. Pugazhenthi
Keyword(s):  
Aqueous Solution ◽  
Performance Assessment ◽  
Composite Membrane ◽  
Ceramic Composite ◽  
Hydrothermal Crystallization ◽  
Separation Potential ◽  
Crystallization Method

The aim of this work is to fabricate an analcime-C composite membrane by anin situhydrothermal crystallization method and investigate its separation potential by the ultrafiltration of Cr(vi) from aqueous solution.

Replacing sulfonate by carboxylate: application of pyridyliminocarboxylato copper(II) complexes in rac-lactide polymerization and Chan–Evans–Lam coupling

2019 ◽  
Vol 97 (3) ◽  
pp. 178-190 ◽  
Author(s):  
Valérie Hardouin Duparc ◽  
Clémentine Dimeck ◽  
Frank Schaper
Keyword(s):  
Molecular Sieves ◽  
Weight Control ◽  
Phenylboronic Acid ◽  
Side Reactions ◽  
X Ray Diffraction ◽  
Reaction Conditions ◽  
One Pot ◽  
X Ray ◽  
Induction Periods ◽  
Lactide Polymerization

Copper(II) complexes carrying pyridylmethyleneaminobenzoate or –propanoate ligands, LCuX, were prepared in one-pot reactions from pyridinecarboxaldehyde, aminobenzoic acid or β-alanine, and CuX2 (X = Cl, NO3, OAc, or OTf). All complexes were characterized by single-crystal X-ray diffraction studies and formed either dimers, tetramers, or coordination polymers. Attempted preparation of the respective alkoxide complexes, LCu(OR), was unsuccessful, but use of LCuX/NaOMe mixtures in rac-lactide polymerization indicated under some conditions coordination–insertion polymerization via a copper alkoxide as the mechanism. The complexes performed poorly in rac-lactide polymerization, showing low activities (12 h to completion at 140 °C), low to moderate heterotacticity (Pr = 0.6–0.8), and poor polymer molecular weight control (intramolecular transesterification). They were competent catalysts for Chan–Evans–Lam couplings with phenylboronic acid, without any indication of side reactions such as deboration or aryl homocoupling. The complexes were active in undried methanol, without addition of base, ligand, or molecular sieves. Aniline, n-octylamine, and cyclohexylamine were coupled quantitatively under identical reaction conditions. There is only little influence of the anion on activities (less than a factor of 2) but a strong influence on induction periods. The complexes were not active in CEL coupling with alcohols, phenols, or alkylboronic acids.

Comparison of Catalytic Cracking Performance between Riser Reactor and Microactivity Test (MAT) Unit

2001 ◽  
Vol 15 (4) ◽  
pp. 783-785 ◽  
Author(s):  
Siauw Ng ◽  
Hong Yang ◽  
Jinsheng Wang ◽  
Yuxia Zhu ◽  
Craig Fairbridge ◽  
...  
Keyword(s):  
Catalytic Cracking ◽  
Riser Reactor ◽  
Cracking Performance

FIBRINOPEPTIDE B RELEASE FROM NORMAL FIBRINOGEN AND FIBRINOGEN LONDON I IN THE PRESENCE OF INHIBITORS OF FIBRIN POLYMERIZATION

1987 ◽  
Author(s):  
W Ruf ◽  
A Bender ◽  
K T Preissner ◽  
D A Lane ◽  
G Müller-Berghaus
Keyword(s):  
Initial Phase ◽  
Slow Rate ◽  
Order Reaction ◽  
Pseudo First Order Reaction ◽  
Reaction Conditions ◽  
Fibrin Polymerization ◽  
First Order ◽  
Molar Excess ◽  
Pseudo First Order ◽  
Fibrinogen Molecule

The fibrinopeptides A and B (FPA and FPB) are cleaved from the fibrinogen molecule with different rates. In the initial phase of the thrombin-fibrinogen reaction, FPB is released with a slow rate, which is enhanced upon polymerization of desA-fi-brin monomers. The aim of the present study was to further characterize the mechanism leading to the enhanced rate of FPB release during polymerization. For this purpose, the release of FPB from normal fibrinogen and from fibrinogen London I, which exhibits a polymerization defect located in the D-domain, was studied in the presence and absence of the fibrinolytic fragment D1 (D1) and of the synthetic tetrapeptide Gly-Pro-Arg-Pro (GPRP). Steady state parameters for fibrinopeptide release were determined under pseudo-first order reaction conditions. In the initial phase of the thrombin-fibrinogen reaction, the release of FPA was unchanged in the presence of D1. Furthermore, the release of FPA from fibrinogen London I did not reveal any difference in comparison to normal fibrinogen. GPRP prevented not only fibrin polymerization, but also the enhanced rate of FPB release. On the contrary, the rate of FPB release in the presence of a 16- and 32-fold molar excess of over fibrinogen did not differ from a reaction mixture with no added D1. Si-miliar to the inhibited rate of FPB release in the presence of GPRP, the release of FPB from fibrinogen London I occurred with a slow rate, which was not enhanced by the addition of a 16-fold molar excess of D1. Since the release neither from normal fibrinogen nor from ribrinogen London I was affected by D1, it was concluded that the D-E contact formed by D1 with an E-domain of a desA-fibrin molecule does not enhance the release of FPB. While GPRP keeps fibrin in monomeric form by inhibiting the polymerization sites in the D-domains, D1 does not prevent the formation of fibrin oligomers. Therefore, acceleration of FPB release is caused by a conformational change, which is induced by binding of reciprocal polymerization sites to an E-as well as a D-domain of the same desA-fibrin molecule.

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