Ethylene to 2‐Butene in a Continuous Gas Phase Reaction using SILP‐Type Cationic Nickel Catalysts

Abstract

Owing to shifting market demands, it is important to convert ethylene to propylene. One attractive way to achieve this conversion is the dimerization of ethylene to 1‐butene, followed by isomerization to 2‐butene and subsequent metathesis of 2‐butene/ethylene olefin. Our contribution focuses on combining the first two steps. Herein, we report a highly selective tandem dimerization/isomerization of ethylene to 2‐butene catalyzed by homogeneously dissolved cationic nickel complexes. These catalysts can be efficiently immobilized by using the supported ionic liquid phase technology. Such supported ionic liquid phase materials have been tested under continuous gas phase conditions and demonstrated attractive catalytic performance with respect to both catalyst stability and productivity after the optimization of support, ionic liquid, ligand, and process parameters. The limited thermal stability of the nickel complexes and olefin condensation at too low temperatures require a careful thermal management of the fixed‐bed reactor.

Bio‐based propylene production in a sugarcane biorefinery: A techno‐economic evaluation for Brazilian conditions

“…Th e second required stream, of 2-butene, is obtained by conjoint dimerization/isomerization of ethylene to 2-butene catalyzed by homogeneously dissolved cationic nickel complexes at 1 bar and 40 o C. Th e considered process follows the description presented by Scholz et al 15 Finally, ethylene is blended with recycled ethylene (from the end of metathesis process), while 2-butene is blended with recycled 2-butene. Ethylene and 2-butene are then mixed and heated in a fi red heater to 300 o C before entering the fi xed-bed metathesis reactor, using a tungsten oxide catalyst supported on silica.…”

Long-alkyl-chain-derivatized imidazolium salts and ionic liquid crystals with tailor-made properties

“…25 Attempting to improve the selectivity of catalytic reactions by creating a pre-organized, well-ordered reaction environment (e.g. for olen dimerization catalysis), we also studied the use of the newly synthesized 27 Therefore, we focused our subsequent research on nding conveniently tunable ionic liquid crystal solvents with liquid crystalline phases at room temperature.…”

“…One example is the dimerization of ethylene with Ni-based SILP-type catalysts based on [C 2 MIM][FAP] (with FAP ¼ tris(pentauoroethyl)triuorophosphate anion). 27 Therefore, we focused our subsequent research on nding conveniently tunable ionic liquid crystal solvents with liquid crystalline phases at room temperature.…”

Unlocking the potential of supported liquid phase catalysts with supercritical fluids: low temperature continuous flow catalysis with integrated product separation

“…Gas-phase ethylene dimerization to 2-butenes catalysed by cationic Ni(II) complexes bearing chelating P−O ligands in EMIM FAP on dehydroxylated silica gel was also studied in continuous flow [ 146 ]. Initially, high conversion and selectivity were observed in the first 10 h on stream after which rapid deactivation due to progressive thermal runaway along the fixed-bed reactor occurred.…”