Peng Xie

Production of light olefins and aromatic hydrocarbons through catalytic cracking of naphtha at lowered temperature

Naphtha catalytic cracking were carried out at 650°C over modified ZSM-5. Light olefins and BTX could be obtained over the catalysts. The products showed variable distribution with different catalyst modification. Some modification, such as Fe, Cu and La favored the BTX generation and P and Mg modification favored the light olefins production. In N 2 stream cracking catalyzed by LaZSM-5, more than 50% naphtha feed were converted to BTX, while in steam cracking, with an improved modified catalyst, P, La/ZSM-5, naphtha can be converted to light olefins with high activity and long-term stability.

The effect of acidity and pore structure of catalysts on the dehydroisomerization of n-butane to isobutene

Four molecular sieves of ALPO-11 and SAPO-5, 11, 34 were synthesized and characterized. The results showed the differences of acidity and porous structure. The four samples were modified by Pd and used in the direct transformation of n-butane to isobutene. Pd/AIPO-11, Pd/SAPO-5 and Pd/SAPO-34 showed low catalytic activity and poor selectivity for isobutene, while Pd/SAPO-11 showed relatively high activity and high isobutene selectivity. The effect of acidity and porous structure on the support Pd and the catalytic performance were discussed. Medium strong acidity and suitable pore geometry were necessary in this reaction.

Dehydroisomerization of n-butane to isobutene over Pd/SAPO-11 the effect of Si content of SAPO-11, catalyst preparation and reaction condition

The SAPO-11 molecular sieves with different Si content were synthesized and modified by Pd for direct transformation of n-butane to isobutene. The effects of Si content of SAPO-11, catalyst preparation and reaction condition were studied. The catalytic properties of Pd/SAPO-11 varied with Si content of the crystal products. The impregnation time of the catalyst had effect on the product distribution and catalytic activity. The catalytic properties also changed with the reaction time.

Production of isobutene from n-butane over Pd modified SAPOs and MeAPOs

Abstract Pd modified A1PO-11 and SAPO-5, 11, 34 were used in the direct transformation of n-butane to isobutene. The effect of acidity and porous structure on the supported Pd and the catalytic performance were discussed. For higher isobutene selectivity, some metals, such as Ti, Fe, Mg, Co and Mn, was incorporated into A1PO-11 framework and isobutene selectivity of 34.86% can be obtained over Pd/MnAPO-11. A combined catalyst system was used for a further improvement of the isobutene selectivity.