Optimization of Isomerization Activity and Aromatization Activity in Catalytic Naphtha Reforming over Tri-Metallic Modified Catalyst using Design of Experiment Based on Central Composite Design and Response Surface Methodology

Abstract

In this work, the estimation capacity of the response surface methodology (RSM), in the catalytic naphtha reforming to enhance the octane number of reformats via isomerization reaction pathway and minimize the aromatization activity over tri-metallic modified Pt-Re/Al2O3 catalyst were investigated by applying Design of experiment (DOE). The parent bimetallic catalysts were modified using a relatively inactive metal (Sn) by means of employing non-conventional method of anchoring technique called controlled surface reaction (CSR) method in order to favor the intimate contact of Sn with the active phase to suppress the metallic character of Pt metal. The correlations between RON, aromatization and isomerization activities with three reaction variables namely temperature (480-510 o C), pressure (10-30 bar) and space velocity LHSV (1.2-1.8 h-1) were presented as empirical mathematical models via reforming of a complex mixture (80 o C-185 o C). Numerical results indicated that the minimum aromatization activity was 20% when reaction temperature was 460 o C and pressure of 35 bar. Results also show that maximum isomerization activity of 58% was achieved when pressure is 30 bar and space velocity is 1.8 h. it has been found that optimum value of RON = 89 was attained at 449.9 o C, 32 bar and 1.7 h-1. However, high operating pressure and low reaction temperature significantly decrease the aromatization activity coupled with substantial decrease in RON which can be enhanced by producing high yield of isomers.

n‐Heptane reforming over Pt/Zr‐HMS catalysts for modeling and optimization of RON and operating conditions via response surface methodology

“…The study was done over three reaction variables, namely, temperature, pressure and space velocity (LHSV) using design of experiment based on central composite design and RSM. The results present that the optimum conditions to obtain minimum aromatization activity (20%), maximum isomerization activity (58%), and RON (89) are equal to T = 460°C and P = 35 bar, P = 30 bar, and LHSV = 1.8 h, and 449.9°C, 32 bar and 1.7 h −1 , respectively 13 …”

“…The results present that the optimum conditions to obtain minimum aromatization activity (20%), maximum isomerization activity (58%), and RON (89) are equal to T = 460 C and P = 35 bar, P = 30 bar, and LHSV = 1.8 h, and 449.9 C, 32 bar and 1.7 h À1 , respectively. 13 In 2016, Elfghi evaluated a quadratic polynomial equation of RSM model in catalytic naphtha reforming over bi-functional Pt-Re-S/ Al 2 O 3 Cl catalysts. The results demonstrated that two variables of the reaction temperature and pressure have the greatest effect on naphtha reforming.…”

“…Statistical assessment accomplished by Parsafard et al presented that catalyst molar ratio, temperature and time on stream are influential factors that enable us to effectively estimate isomerization reaction with RSM on the mesoporous active samples. 15 Although the articles mentioned above investigated the effect of temperature, total pressure and space velocity parameters on the catalytic activity affected the catalytic performance of the naphtha reforming process, 5,13,14 there is no report regarding the investigation of the effect of the catalyst molar ratio, temperature and time on stream parameters in the n-heptane reforming reaction using the Pt/Zr-HMS catalysts.…”

“…Although the articles mentioned above investigated the effect of temperature, total pressure and space velocity parameters on the catalytic activity affected the catalytic performance of the naphtha reforming process, 5,13,14 there is no report regarding the investigation of the effect of the catalyst molar ratio, temperature and time on stream parameters in the n‐heptane reforming reaction using the Pt/Zr‐HMS catalysts.…”

A hybrid statistical approach for modeling and optimization of RON: A comparative study and combined application of response surface methodology (RSM) and artificial neural network (ANN) based on design of experiment (DOE)

“…The evaluation of a pilot plant performance for catalytic naphtha reforming is complicated because of the competing of varies successive reactions taking place subsequently such as dehydrogenation and dehydroisomerization of naphthenes to aromatics, dehydrogenation of paraffins to olefins, dehydrocyclization of paraffins and olefins to aromatic, isomerization or hydroisomerization to isoparaffins, isomerization of alkylcyclopentanes, and substituted aromatics and hydrocracking of paraffins and naphthenic to lower invaluable hydrocarbons [16,17]. The above subsequent/successive reactions occurred because the composition of the real feedstock is sophisticated and very complex as it contains hundreds of hydrocarbons, hence, the use of model compound as a reactant feed is highly recommended as well as the development and adaptation of detailed experimental procedures using Design of Experiment (DOE) approach based on Central Composite Design (CCD) technique coupled with different modeling and optimization tools such as RSM and ANN are extremely important in order to attain reliable data [18][19][20].…”