Catalyst and process for producing light aromatic hydrocarbons and light alkanes from hydrocarbonaceous feedstock

Abstract

The present invention provides a catalyst comprising metallic Pt and / or Pd supported on a binder-free zeolite for producing light aromatic hydrocarbons and light alkanes from hydrocarbonaceous feedstock, wherein the amount of metallic Pt and / or Pd is of 0.01-0.8 wt %, preferably 0.01-0.5 wt % on the basis of the total weight of the catalyst, and the binder-free zeolite is selected from the group consisting of mordenite, beta zeolite, Y zeolite, ZSM-5, ZSM-11 and composite or cocrystal zeolite thereof. The present invention also provides a process for producing light aromatic hydrocarbons and light alkanes from hydrocarbonaceous feedstock using said catalyst.

Description

TECHNICAL FIELD [0001]The present invention relates to a catalyst as well as the corresponding process for producing light aromatic hydrocarbons and light alkanes from hydrocarbonaceous feedstock.BACKGROUND ART [0002]Regarding the separation of aromatic hydrocarbons BTX,i.e.benzene, toluene and xylene, from non-aromatic hydrocarbons, some catalytic conversion processes have been developed in the prior art. For example, U.S. Pat. No. 3,729,409 disclosed converting non-aromatic hydrocarbons to lower alkanes by hydrocracking reaction and then separating aromatic hydrocarbons from non-aromatic hydrocarbons through gas-liquid separation; U.S. Pat. No. 5,865,986 and U.S. Pat. No. 6,001,241 disclosed a process for upgrading naphtha fraction, wherein a zeolite-based catalyst is used in some reactors to improve the production of aromatic hydrocarbons; and CN1217892C disclosed a similar process, wherein reformate, pyrolysis gasoline and the like are upgrade to produce LPG and light aromatic h...

AI Technical Summary

Benefits of technology

The present invention provides a catalyst for producing light aromatic hydrocarbons and light alkanes from hydrocarbonaceous feedstock. The catalyst uses a binder-free zeolite as a support for metallic catalytic active components, which results in a catalyst with large acid density, unobstructed pores, and moderate hydrogenation activity. The catalyst can be easily separated from the hydrocarbonaceous feedstock and has high stability. The process for producing light aromatic hydrocarbons and light alkanes using the catalyst is simple and efficient.

Problems solved by technology

The acidic catalyst used in these catalytic conversion processes would deactivate quickly due to coke and / or carbon-deposition, although this can be alleviated by supporting the metals with high hydrogenation activity and the hydrogenation activity of the catalyst also can be adjusted by varying the amount and / or the distribution of the supported metals, however, too high hydrogenation activity on the metallic center may result in side reaction of saturation of aromatic rings.

This is because the shaped catalysts are widely used in industries and have to suffer from various stresses during its use, thus, sufficient mechanical strengths are necessary for ensuring the whole catalytic process to be conducted smoothly, otherwise if the shaped catalysts have poor mechanical strengths, some problems such as the lines being blocked by fine powders, the liquid being distributed unevenly, the pressure drop being increased and the like would be introduced, so as to lead to poor catalytic efficiency, and even a unexpected shut-down in worse case.

However, introduction of binders during shaping the zeolite powders would reduce the concentration of effective components in the zeolite particles, result in reduced effective surface area, thus the adsorption value would be reduced.

This is because some binders would enter into part of channels of the zeolite or block part of pores of the zeolite, thus limiting the diffusion, resulting in poor adsorption ability and adsorption selectivity as well as reduced rates of adsorption and desorption, further the reduced activity and selectivity in the catalytic reactions; furthermore, undesired side reactions may be initiated in the presence of binders.