Continuous Hydroformylation Research Articles

Continuous hydroformylation of 1-decene in an aqueous biphasic system enabled by methylated cyclodextrins

Long-term applications of cyclodextrins in the aqueous biphasic hydroformylation of higher olefins with high selectivities and simultaneous catalyst recycling.

Detailed Investigation of the Mechanism of Rh-Diphosphite Supported Ionic Liquid Phase (SILP)-Catalyzed 1-Butene Hydroformylation in the Gas Phase via Combined Kinetic and Density Functional Theory (DFT) Modeling Studies

A detailed kinetic investigation of the gas-phase continuous hydroformylation of 1-butene has been carried out. The supported ionic liquid phase (SILP) catalyst was based on a Rh-diphosphite, the ionic liquid [EMIM][NTf2], and silica support material. Based on the established Wilkinson mechanism, the hyperbolic rate expressions were used to fit the experimental results. While the hydroformylation could be modeled with high accuracy, the hydrogenation and isomerization trends could not be reproduced by the given rate expressions. An alternative reaction mechanism was developed and allowed an excellent fit of experimental data by the new reaction rate expressions. Initial steps of the mechanism were studied using density functional theory (DFT) calculations.

Superhydrophobicity: Constructing Homogeneous Catalysts into Superhydrophobic Porous Frameworks to Protect Them from Hydrolytic Degradation

Summary Hydrolytic degradation has caused numerous efficient catalytic systems to suffer because in many cases it is impossible to fully exclude water from the reaction systems. Here, we demonstrate an effective strategy of stabilizing water-sensitive organic-ligand-based homogeneous catalysts by constructing them into a superhydrophobic porous framework, which renders them extraordinarily water resistant yet fully retains their intrinsic catalytic activities under heterogeneous systems. Representatively, after metalation of the superhydrophobic porous phosphite-ligand-based framework with Rh species, the resultant catalyst exhibits superior activities and dramatically enhanced durability in mimic continuous hydroformylation processes of the internal olefins in comparison with the homogeneous counterparts. In addition, because it is solid in nature, the catalyst can be readily recycled with negligible loss of performance. Given the modular nature and the broad scope of organic ligands, our work opens a new avenue for stabilizing water-sensitive homogeneous catalysts into highly water-tolerate heterogeneous catalysts.

Continuous Hydroformylation with Phosphine-Functionalized Polydimethylsiloxane Rhodium Complexes as Nanofilterable Homogeneous Catalysts

Commercially available polydimethylsiloxane (PDMS) was functionalized with phosphine and used to form a Rh complex catalyst. The PDMS-based Rh catalyst complex shows promise as an inexpensive, readily synthesized and nanofilterable homogeneous catalyst for performing continuous hydroformylation. Batch hydroformylation of several substrates including 1-octene, 1-decene, 1-dodecene and styrene showed good activity and selectivity. For 1-octene hydroformylation, the observed catalyst activity with the PDMS-based Rh complex is 2-fold greater compared to that with a conventional Rh-triphenylphosphine complex under similar conditions. Continuous 1-octene hydroformylation for up to 120 h was demonstrated in a membrane nanofiltration system, showing stable conversion (∼60%) and high chemoselectivity (>95%). The total turnover number (TON) after 120 h was approximately 12 000 and the permeate Rh concentration was <2 ppm.

Enhanced hydroformylation by carbon dioxide‐expanded media with soluble Rh complexes in nanofiltration membrane reactors

A novel process for continuous hydroformylation in CO2‐expanded liquids (CXLs) is demonstrated using bulky phosphite ligands that are effectively retained in the stirred reactor by a nanofiltration membrane. The reactor is operated at 50°C with a syngas pressure of 0.6 MPa to avoid CO inhibition of reaction rate and selectivity. The nanofiltration pressure is provided by ∼3.2 MPa CO2 that expands the hydroformylation mixture and increases the H2/CO ratio in the CXL phase resulting in enhanced turnover frequency (∼340 h−1), aldehydes selectivity (&gt;90%) and high regioselectivity (n/i ∼8) at nearly steady operation. The use of pressurized CO2 also reduces the viscosity in the CXL phase, thereby improving the mass‐transfer properties. Constant permeate flux is maintained during the 50 h run with Rh leakage being less than 0.5 ppm. This technology concept has potential applications in homogeneous catalytic processes to improve resource utilization and catalyst containment for practical viability. © 2013 American Institute of Chemical Engineers AIChE J, 59: 4287–4296, 2013

Process Design for the Separation of Three Liquid Phases for a Continuous Hydroformylation Process in a Miniplant Scale

Within the framework of the Collaborative Research Centre SFB/TR 63 InPROMPT, “Integrated chemical processes in liquid multiphase systems”, a novel process concept for the hydroformylation of long chain alkenes to aldehydes in microemulsions is investigated and developed at the Berlin Institute of Technology (Technische Universitat Berlin), Germany. To start the hydroformylation reaction, a hydrophilic rhodium-ligand-complex is required. By applying a nonionic surfactant, a microemulsion system is formed and thus the hydrophilic catalyst is transported into the hydrophobic alkene phase. Next to achieve a high conversion rate in the continuously stirred tank reactor, the separation of the valuable rhodium catalyst from the product phase poses a challenge. This separation is the crucial step for the technical and economic feasibility of the overall process concept and plant design. Owing to the lack of thermodynamic data for microemulsion mixtures, the design of the phase separation unit strongly depends on...

Ligand Effects on the Surface Composition of Rh‐Containing Ionic Liquid Solutions Used in Hydroformylation Catalysis

In hydroformylation, multiphase catalysis is a well-established and industrially realized method for effective catalyst separation and recycling. Aqueous phase liquid–liquid biphasic catalysis was developed through the pioneering discovery of the highly water-soluble ligand tris(3-sodium sulfonatophenyl)phosphine (tppts, 1) by Kuntz in 1976. This ligand concept enabled the industrial realization of aqueous hydroformylation for propene hydroformylation in the Ruhrchemie–Rh ne–Poulenc process. The process went on stream in 1984, and is still operating today (550000 tons per year). However, the limited solubility of higher olefins (>C4) in water has prompted much research activity into alternative polar catalyst media for liquid–liquid multiphase hydroformylation. Among these endeavors, the use of lowmelting salts, so-called ionic liquids (ILs), has attracted particular interest as many ionic liquids show sufficiently high solubilities for higher olefins to allow reasonable reaction rates. First reports on the application of ionic liquids in Rh-catalyzed hydroformylation were published by Chauvin s group in 1995. Already in this first paper, the use of sulfonated triphenylphosphine ligands was highlighted as a crucial precondition to avoid Rh-leaching into the organic product phase. Later, sulfonated triphenylphosphine ligands were also combined with imidazolium counter ions. ColeHamilton and co-workers suggested, for example, [C3mim]2ACHTUNGTRENNUNG[PhP ACHTUNGTRENNUNG(C6H4SO3)2] as a suitable ligand for hydroformylation reactions in the biphasic system ionic liquid/scCO2. [7] The same ligand system was applied recently to an even more efficient catalytic system using the ionic catalyst solution in the form of a supported ionic liquid phase (SILP). Such SILP catalytic systems have also been very successfully applied in continuous gas-phase reactions where the ionic liquid film supported on a highly porous inorganic support is contacted directly with the gas-phase of the reactants to perform continuous hydroformylation using a continuous fixed-bed reactor. In general, hydroformylation in ionic liquids has produced a huge amount of scientific activity over the last 15 years and particular progress was made by the use of regioselective ionic ligand systems and by the application of ionic liquids carrying halide-free, cheap and hydrolytic stable anions. The field has been recently summarized comprehensively in an excellent review by Haumann and Riisager. In multiphase catalysis, interface processes such as substrate diffusion into the catalyst phase, the reaction rate at the phase boundary (in comparison to reaction rate in the bulk), and product diffusion back into the organic phase play a crucial role for the overall performance of the system. Despite this obvious fact, experimental investigations into the chemical nature of the liquid surface of catalytic systems are lacking so far. This is even more surprising in the light of recent theoretical findings by the group of Wipff, which demonstrated that the composition of the catalytic interface may well be very different from the average chemical composition of two adjacent bulk liquid phases. This fact is of high relevance for the detailed understanding of all above-mentioned interface transport and reaction processes. Moreover, the authors demonstrated that the surface-active character of a given type of an IL soluble complex was similar at the IL–vacuum interface and at the IL interface with weakly polar organic solvents. The [a] Dipl.-Chem. C. Kolbeck, Dipl.-Chem. T. Cremer, Dr. F. Maier, Prof. Dr. H.-P. Steinr ck Chair of Physical Chemistry II Friedrich-Alexander-Universit t Erlangen-N rnberg Egerlandstrasse 3, 91054 Erlangen (Germany) Fax: (+49)9131-852-8867 E-mail : steinrueck@chemie.uni-erlangen.de [b] Dipl.-Chem. N. Paape, Dr. P. S. Schulz, Prof. Dr. P. Wasserscheid Lehrstuhl f r Chemische Reaktionstechnik Friedrich-Alexander-Universit t Erlangen-N rnberg Egerlandstrasse 3, 91058 Erlangen (Germany) [] These authors contributed equally to this work.

Water-soluble metal complexes and catalysts. Part 7 . New efficient water-soluble catalysts for two-phase olefin hydroformylation: BINAS-Na, a superlative in propene hydroformylation

The monophosphine 3,4-dimethyl-2,5,6-triphenyl-1-phosphanorborna-2,5-diene ( 1, DMTPPNOR) and the diphosphine 2,2′-bis (diphenylphosphinomethyl)-1,1′-binaphthalene ( 7) were sulfonated by means of oleum. The sulfonation products 8 (BINAS) and 2 (NORBOS) were purified by extraction-reextraction and by gel permeation chromatography. While the sodium salt 9 (BINAS-Na) of BINAS ( 8) was accessible as a mixture of different degrees of sulfonation, the sodium salt of NORBOS ( 2) was available as an analytically clean, completely characterized, triply sulfonated compound, NORBOS-Na ( 3). For the synthesis of 2,2′-bis (diphenylphosphinomethyl)-1,1′-binaphthalene ( 7), a new method has been used: Commercially available 1-bromo-2-methylnaphthalene ( 4) was first dimerized by means of magnesium, and then the resulting 2,2′-dimethyl-1,1′-binaphthalene ( 5) was treated with n- BuLi TMEDA and chlorodiphenylphosphine. In the ‘heterogeneous’ (bi-phasic) hydroformylation of propene, the sulfonated ligands 3 and 9 exhibited very high activities and productivities at low phosphine/rhodium ratios. Furthermore, phosphine 9 was advantageous in n/iso ratios of the resulting butyric aldehyde (rhodium catalysis). The new catalyst system Rh I/BINAS-Na has an apparent activation energy of 10.8 kcal/mol explaining the outstanding performance of this system in continuous hydroformylation, with the activity data being: 16 (TPPTS), 90 (BISBIS-Na), 118 (NORBOS-Na), and 178 (BINAS-Na).

ChemInform Abstract: Selective Rhodium‐Catalyzed Hydroformylation with the Tri‐ and Tetraphosphine Ligands (CH3)1,0Si(CH2CH2PPh2)3,4. Formation of Rh(Si(CH2CH2PPh2)3)(CO) via CH3‐Si Bond Cleavage and Structure of This Rh(I)‐Si Bonded Complex.

AbstractThe flexible, nonchelating phosphine ligands (III) are prepared and used in th Rh‐catalyzed hydroformylation of 1‐butene (IV) to yield unusually high selectivity to the linear aldehyde product (VII) at low (III)/Rh ratios of 3‐4. During continuous hydroformylation with the ligand (IIIa), the inactive title complex (VIII) is formed.