Olefin Oligomerization Process

Abstract

Disclosed is a process for producing a hydrocarbon fraction rich in components boiling in the range typical for diesel fuel comprising contacting a feedstock comprising one or more C 2 to C 10 alkenes with a zeolite catalyst having partially neutralised acidity and a one-dimensional or two dimensional micropore structure consisting of channels made from rings containing between 10 and 12 silicon / aluminium atoms at a temperature in the range 373 to 773 K and pressure in the range 0.1 to 200 bar characterised in that the partially neutralized zeolite catalyst contains both protons and basic cations. The basic cations are preferably selected from the group comprising Group IA and IIA cations (preferably sodium, potassium, caesium or mixtures thereof). Relative to their equivalent fully protonic forms the partially neutralized zeolite catalysts described show improved catalyst life and selectivity to hydrocarbons

Description

technical field [0001] The present invention relates to a heterogeneous process for the oligomerization of olefins to produce hydrocarbon fractions suitable for use as diesel fuel. In particular, the present invention relates to a process using as catalyst a zeolite of the MFI or TON type, most preferably theta-1 (TON) type, which has a partially neutralized acidity. Background technique [0002] Oligomerization of light olefins, such as propylene and butene, represents an important industrial route to produce environmentally friendly synthetic liquid fuels free of sulfur and aromatics. These processes, depending on the exact nature of the catalyst and its operating conditions, allow the preparation of mixtures of olefins in the gasoline or diesel boiling range. For example, it is known that high temperature (>300°C) and low pressure (≤30 bar) will increase gasoline yield, while lower temperature and higher pressure will favor the formation of heavier oligomers in the di...

AI Technical Summary

Problems solved by technology

However, to obtain high-quality products, the degree of branching needs to be limited

To this end, two strategies have been proposed in the prior art: controlling and modifying the catalytic sites in the catalyst (such as the strength of its acidity or the nature of its local environment), and using specific zeolite catalysts as follows, which The microporous structure of zeolite catalysts imparts 'shape selectivity' to the oligomerization process, affecting the relative kinetics of linear and branched chain growth

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