Study the activity of platinum and palladium zeolite supported catalysts for hydro carbon reactions

مقدم أطروحة جامعية

Ilayyan, Hiyam Muhammad Abd al-Rahim

الجامعة

الجامعة التكنولوجية

الكلية

-

القسم الأكاديمي

قسم الهندسة الكيمياوية

دولة الجامعة

العراق

الدرجة العلمية

ماجستير

تاريخ الدرجة العلمية

1998

الملخص الإنجليزي

In recent years zeolite catalysts have become more and more important m modern oil refining and in the petrochemicals industry.

This broad range of application of zeolites for many catalytic processes is mainly due to their framework structure.

Preparation and catalytic activity of Pt, Zeolite loaded with (0.4 % Pt and Pd) catalysts were investigated on hydrosol version (isomerization on, cracking and cyclization) of n-hexane.

Two types of crystalline zeolites were used as supports fur platinum and palladium catalysts.

One of them, ZSM-5 type was synthesized in the laboratory, while the other was Faujasite type Y with Silos / AI2Oj ratio of 45.0 and 5.0 respectively.

All forms of zeolites i.e., the decationized and canonic divalent such as barium and strontium were prepared from a monovalent cationic sodium Type by means of ibaexchange process at different conditions with appropriate salt solution.

This modification was earned out to improve the catalytic properties of platinum and palladium-zeolite catalysts.

The platinum and palladium loaded zeolite (0.4 wt % Pt and Pd) prepared by impregnation of the modified zeolites with hexachlorophene acid and palladium chloride respectively.

The prepared catalysts cabined and reduced at different pretreatment conditions.

X-ray diffraction and chemical analysis techniques were used to characterize and identify the prepared ZSM-5 zeolite.

Tie catalytic behavior was studied on n-hexane hydro conversion in a fixed bed micro-catalytic reactor.

The influence of reaction temperature and yens to hydrocarbon mole ratio were investigated at a pressure.

In addition, diffusion parameters were calculated over the temperature range studied (300-400°C).

The prepared catalysts exhibited different activities toward n-hexane isomerization, hydrocracking and cyclization ; the reaction temperature influences the activity of Pt Pd / exchanged zeolite Y and ZSM-5 to comparatively higher extent than the hydrogen / hydrocarbon ratio.

These catalysts have high activity toward isomerization at low temperature.

At higher temperature the selectivity toward hydrocracking is increased.

Thus platinum decationized zeolite Y has a good activity toward isomerization and cyclization compared with other platinum supported catalysts.

Moreover, Pd / BaZSM-5 shows high isomerization selectivity at low temperature A correlation of diffusion parameters with catalytic behavior shed some light on the influence of framework structure and type of metal loaded on the effectiveness factor (n) of the selected types of catalysts.

However, high values of this parameter indicate that Pt / HY and Pd / Ba ZSM-5 exhibit small diffusion limitation which verifies the conclusion that the reaction is surface reaction limited atmospheric.

التخصصات الرئيسية

الكيمياء

الموضوعات

• الهيدروكربونات

• APA
• MLA
• AMA

لغة النص

الإنجليزية

نوع البيانات

رسائل جامعية

رقم السجل

BIM-306168