Kinetic Investigation of Catalyst Deactivation in Catalytic Reforming of Naphtha

2012 ◽  
Vol 7 (1) ◽  
Author(s):  
Majid Mohadesi ◽  
Hosnie Sadat Mousavi
Keyword(s):  
Objective Function ◽  
Octane Number ◽  
Catalyst Deactivation ◽  
Oil Refining ◽  
Outlet Temperature ◽  
Catalytic Reforming ◽  
In Series ◽  
Experimental Values ◽  
Definition Of ◽  
High Octane

Abstract Catalytic reforming of naphtha is one of the important processes for converting the naphtha with low octane number to high octane number gasoline. One the main problems in this process are deactivation of its catalysts. The catalytic reforming unit of Tabriz oil refining company was investigated in this article. This unit uses four radial reactors in series, and the Smith’s model was used for its reaction kinetics. Several models were considered for activity of catalysts to determine the major reason of catalyst deactivation. Presented models have parameters, as the objective function is optimized these parameters are obtained. In definition of the objective function the outlet temperature of reactors and outlet composition of fourth reactor should have high overlapping with experimental values. Optimization shows that deposition of coke and slightly high temperature cause the deactivation of catalysts in catalytic reforming of naphtha.

scholarly journals Mathematical modeling and optimization of semi-regenerative catalytic reforming of naphtha

2021 ◽  
Vol 76 ◽  
pp. 64
Author(s):  
Emilia Ivanchina ◽  
Ekaterina Chernyakova ◽  
Inna Pchelintseva ◽  
Dmitry Poluboyartsev
Keyword(s):  
Octane Number ◽  
Catalyst Deactivation ◽  
Formation Rate ◽  
Coke Formation ◽  
Space Velocity ◽  
Catalyst Stability ◽  
Hydrocarbon Mixture ◽  
Catalytic Reforming ◽  
Modeling And Optimization ◽  
Petroleum Refineries

Catalytic naphtha reforming is extensively applied in petroleum refineries and petrochemical industries to convert low-octane naphtha into high-octane gasoline. Besides, this process is an important source of hydrogen and aromatics obtained as side products. The bifunctional Pt-catalysts for reforming are deactivated by coke formation during an industrial operation. This results to a reduction in the yield and octane number. In this paper modeling and optimization of a semi-egenerative catalytic reforming of naphtha is carried out considering catalyst deactivation and a complex multicomponent composition of a hydrocarbon mixture. The mathematical model of semi-egenerative catalytic reforming considering coke formation process was proposed. The operating parameters (yield, octane number, activity) for different catalysts were predicted and optimized. It was found that a decrease in the pressure range from 1.5 to 1.2 MPa at the temperature 478–481 °C and feedstock space velocity equal to 1.4–1 h induces an increase in the yield for 1–2 wt.% due to an increase in the aromatization reactions rate and a decrease in the hydrocracking reactions rate depending on the feedstock composition and catalyst type. It is shown that the decrease in pressure is limited by the requirements for the catalyst stability due to the increase in the coke formation rate. The criterion of optimality is the yield, expressed in octanes per tons.

CALCULATION-EXPERIMENTAL METHOD FOR DEFINITION OF LOWEST FREQUENCY IN BENDING VIBRATIONS OF COACH CAR BODY IN VERTICAL PLANE BASED ON IDENTIFICATION OF ITS BENDING STIFFNESS

2020 ◽  
Vol 2020 (9) ◽  
pp. 35-46
Author(s):  
Aleksandr Skachkov ◽  
Viktor Vasilevskiy ◽  
Aleksey Yuhnevskiy
Keyword(s):  
Least Squares Method ◽  
Vertical Plane ◽  
Bending Stiffness ◽  
Dimensional Problem ◽  
Euler Beam ◽  
Bending Vibrations ◽  
Car Body ◽  
Variable Function ◽  
Experimental Values ◽  
Definition Of

The consideration of existing methods for a modal analysis has shown a possibility for the lowest frequency definition of bending vibrations in a coach car body in a vertical plane based on an indirect method reduced to the assessment of the bending stiffness of the one-dimensional model as a Bernoulli-Euler beam with fragment-constant parameters. The assessment mentioned can be obtained by means of the comparison of model deflections (rated) and a prototype (measured experimentally upon a natural body) with the use of the least-squares method that results in the necessity of the solution of the multi-dimensional problem with the reverse coefficient. The introduction of the hypothesis on ratability of real bending stiffness of the prototype and easily calculated geometrical stiffness of a model reduces a multi-dimensional problem incorrect according to Adamar to the simplest search of the extremum of one variable function. The procedure offered for the indirect assessment of bending stiffness was checked through the solution of model problems. The values obtained are offered to use for the assessment of the lowest frequency of bending vibrations with the aid of Ritz and Grammel methods. In case of rigid poles it results in formulae for frequencies into which there are included directly the experimental values of deflections.

scholarly journals On the explicit representation of the trace space $$H^{\frac{3}{2}}$$ and of the solutions to biharmonic Dirichlet problems on Lipschitz domains via multi-parameter Steklov problems

2021 ◽  
Author(s):  
Pier Domenico Lamberti ◽  
Luigi Provenzano
Keyword(s):  
Fourier Series ◽  
Dirichlet Problem ◽  
Lipschitz Domain ◽  
Spectral Properties ◽  
Explicit Representation ◽  
Lipschitz Domains ◽  
Dirichlet Problems ◽  
Trace Space ◽  
In Series ◽  
Definition Of

AbstractWe consider the problem of describing the traces of functions in $$H^2(\Omega )$$ H 2 ( Ω ) on the boundary of a Lipschitz domain $$\Omega $$ Ω of $$\mathbb R^N$$ R N , $$N\ge 2$$ N ≥ 2 . We provide a definition of those spaces, in particular of $$H^{\frac{3}{2}}(\partial \Omega )$$ H 3 2 ( ∂ Ω ) , by means of Fourier series associated with the eigenfunctions of new multi-parameter biharmonic Steklov problems which we introduce with this specific purpose. These definitions coincide with the classical ones when the domain is smooth. Our spaces allow to represent in series the solutions to the biharmonic Dirichlet problem. Moreover, a few spectral properties of the multi-parameter biharmonic Steklov problems are considered, as well as explicit examples. Our approach is similar to that developed by G. Auchmuty for the space $$H^1(\Omega )$$ H 1 ( Ω ) , based on the classical second order Steklov problem.

Lift-Off Lengths in an Optical Heavy-Duty Engine Operated at High Load with Low and High Octane Number Fuels

2018 ◽  
Author(s):  
Marcus Lundgren ◽  
Alexios Matamis ◽  
Zhenkan Wang ◽  
Pablo Garcia Valladolid ◽  
Mattias Richter ◽  
...  
Keyword(s):  
Octane Number ◽  
High Load ◽  
Heavy Duty ◽  
Lift Off ◽  
High Octane

How Does the Definition of the Objective Function Influence the Outcome of History Matching?

2020 ◽  
Author(s):  
G. Eremyan ◽  
I. Matveev ◽  
G. Shishaev ◽  
V. Rukavishnikov ◽  
V. Demyanov
Keyword(s):  
Objective Function ◽  
History Matching ◽  
Definition Of

On the comparison of waiting times in tandem queues

1981 ◽  
Vol 18 (03) ◽  
pp. 707-714 ◽  
Author(s):  
Shun-Chen Niu
Keyword(s):  
Waiting Time ◽  
Queueing System ◽  
Waiting Times ◽  
Distribution Functions ◽  
Partial Ordering ◽  
Tandem Queues ◽  
Order Relations ◽  
Service Distribution ◽  
In Series ◽  
Definition Of

Using a definition of partial ordering of distribution functions, it is proven that for a tandem queueing system with many stations in series, where each station can have either one server with an arbitrary service distribution or a number of constant servers in parallel, the expected total waiting time in system of every customer decreases as the interarrival and service distributions becomes smaller with respect to that ordering. Some stronger conclusions are also given under stronger order relations. Using these results, bounds for the expected total waiting time in system are then readily obtained for wide classes of tandem queues.

scholarly journals The organizational mechanism for the formation of programs for the renovation of cultural heritage objects on the basis of the value approach

2018 ◽  
Vol 193 ◽  
pp. 05004
Author(s):  
Vera Akristiniy
Keyword(s):  
Cultural Heritage ◽  
Objective Function ◽  
Integral Index ◽  
Organizational Mechanism ◽  
Definition Of ◽  
State Programs ◽  
Cultural Heritage Objects ◽  
Efficient Selection ◽  
Optimal Feature ◽  
Selection Of

The article discusses the issues of preservation of cultural heritage objects due to their mass loss by creating a mechanism for the efficient selection of objects subject to renovation. The algorithm for the calculation of the degree of deterioration of the building and the integral index of value is proposed. The problem of definition of the objective function with respect to which is characterized by the objective function of the optimal feature set and the problem of definition of the target functions of state programs of renovation are solving preservation.

Conversion of biomass derived valerolactone into high octane number gasoline with an ionic liquid

2015 ◽  
Vol 17 (2) ◽  
pp. 1065-1070 ◽  
Author(s):  
Jiayu Xin ◽  
Dongxia Yan ◽  
Olubunmi Ayodele ◽  
Zhan Zhang ◽  
Xingmei Lu ◽  
...  
Keyword(s):  
Ionic Liquid ◽  
Octane Number ◽  
High Octane

Biomass-derived γ-valerolactone was converted into high octane number gasoline with SiO2/Al2O3 and [CF3CH2OH2][CF3CH2OBF3] as efficient catalysts.

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