Catalytic Activity of Pt Loaded Zeolites for Hydroisomerization of n-Hexane Using Supercritical CO2

被引：72

作者：

Al-Rawi, Usama A. ^{[1
]}

Sher, Farooq ^{[6
]}

Hazafa, Abu ^{[2
,3
]}

Rasheed, Tahir ^{[7
]}

Al-Shara, Nawar K. ^{[3
,4
]}

Lima, Eder C. ^{[5
]}

Shanshool, Jabir ^{[1
]}

机构：

[1] Al Nahrain Univ, Coll Engn, Baghdad 64074, Iraq

[2] Univ Agr Faisalabad, Dept Biochem, Faisalabad 38000, Pakistan

[3] Int Soc Engn Sci & Technol, Coventry, W Midlands, England

[4] Univ Nottingham, Dept Chem & Environm Engn, Univ Pk, Nottingham NG7 2RD, England

[5] Fed Univ Rio Grande do Sul UFRGS, Inst Chem, BR-91501970 Porto Alegre, RS, Brazil

[6] Coventry Univ, Fac Engn Environm & Comp, Sch Mech Aerosp & Automot Engn, Coventry CV1 5FB, W Midlands, England

[7] Shanghai Jiao Tong Univ, Sch Chem & Chem Engn, Shanghai 200240, Peoples R China

来源：

INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH | 2020年 / 59卷 / 51期

关键词：

ACID SITES; DEALUMINATED MORDENITE; ZSM-5; ZEOLITES; BEA ZEOLITE; ISOMERIZATION; H-ZSM-5; MOR; CRACKING; BETA; OLIGOMERIZATION;

D O I：

10.1021/acs.iecr.0c05184

中图分类号：

TQ [化学工业];

学科分类号：

0817 ;

摘要：

The present study investigates the synthesis of novel strontium (Sr) and barium (Ba) modified crystalline zeolites including Zeolite Socony Mobil-5 (ZSM-5) and Mordenite (MOR) utilizing a batchwise ion-exchange method with an appropriate chloride solution of 3 N at pH 7.2 and 50 degrees C. Modified zeolites (Ba-ZSM-5 and Ba-MOR, Sr-ZSM-5 and Sr-MOR) were coated with an inert metal (Pt) by a novel supercritical CO2 method using PtMe2COD as a precursor for n-hexane hydroisomerization in a microreactor unit at different temperatures (250-325 degrees C), H-2/HC ratios of 3, 6, and 9, and a pressure of 5 bar. The acidic and physical features of Pt loaded zeolites were systematically characterized using FT-IR, XRD, BET surface area measurements, TGA, and TEM techniques. It is found that the metal loading in scCO(2) results in more uniform and very small metal nanopartide (1.37 nm) dispersion with high stability after reduction. It is also revealed that high loading pressure in scCO(2) (280-300 bar) results in higher catalytic activity and surface area. The maximum conversion and selectivity of about 80 and 90% were achieved for n-hexane isomerization at 275 degrees C and a H-2/HC ratio of 6 for Pt/Sr-ZSM-5 catalyst. Results reported that Pt loaded over all zeolites (H-MOR, Sr-MOR, Ba-MOR, H-ZSM-5, Ba-ZSM-5, and Sr-ZSM-5) by the scCO(2) method showed the minimum production of cracking products (C-1-C-5) and maximum isomeric products including iso-C-6 isomers (2,2-DMB, 2,3-DMB, 2-MP, and 3-MP). Furthermore, the overall results of the rate of reaction revealed that Pt/Sr-ZSM-5 and Pt/Ba-ZSM-5 catalysts showed a better rate of isomerization (46.44%) and conversion (47%) for n-hexane at 300 degrees C and a H-2/HC ratio of 9 with a minimum rate of cracking. However, it is conduded that the small, pored size Pt loaded ZSM-5 zeolite showed the highest catalytical activity compared to large pored MOR zeolite making it of great interest for diesel and gasoline formation in the oil refining industry.

引用

页码：22092 / 22106

页数：15