Vapor Phase Carbonylation Of Methanol Research Articles

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Methanol carbonylation (MC) to produce acetic acid is a strategically important large-scale process (Monsanto and BP Chemicals Cativa TM ), which is carried out under high pressure in the liquid phase using Rh(Ir) catalysts and extremely toxic halide cocatalysts/promoters. In addition to acetic acid, methyl acetate is also an industrially important product of MC. The halogen-free heterogeneous-catalytic process of methanol carbonylation in the vapor phase using catalysts containing no noble metal, in particular Ni-based on carbon supports, provides a number of advantages over homogeneous systems, including the possibility of multifold use of catalytic compositions. Important factors that cause the formation of acetyls are the textural, acidic properties of the catalysts, the presence of modifying/promoting additives in their composition. Nickel and copper chlorides supported on activated carbon were shown in [Catal. Today. 2004. 93–95:451] to catalyze the vapor-phase MC process producing methyl acetate at ambient pressure in the absence of alkyl halides in the gas reaction mixture. This paper presents the results of the studying the effect of supports (activated carbon of BAU-A (AC), SKT, SUGS grades; structured – cordierite, Al 2 O 3 /cordierite) of copper-nickel chloride catalysts, characterized by the low-temperature ad/desorption, XRD, TPD-NH 3 , TPR-H 2 techniques; modifying additives of tin on the production of methyl acetate in the halide-free vapor-phase methanol carbonylation under ambient pressure. It is shown that the yield 18 % of the target product in the presence of a catalyst on activated carbon of the BAU-A grade significantly exceeds the Y MeOAc 3 and 7 % indices for NiCl 2 -CuCl 2 compositions on SKT and SUGS, respectively. The formation of methyl acetate on NiCl 2 -CuCl 2 /AC is facilitated by the optimal combination of the porous structure characteristics (the presence of mesopores with an average diameter of ~ 7 nm) and the surface acidity of the specified catalyst, which are favorable for the activation of reagent molecules of the MC process. Methyl acetate yield of 15 % in the presence of NiCl 2 -CuCl 2 compositions on ceramic honeycomb supports (synthetic cordierite) with a specific surface area ~ 0.5 m 2 /g, commensurate at 355–360 °C with Y MeOAc for NiCl 2 -CuCl 2 /AC, is achieved due to more efficient mass transfer and heat removal in the exothermic reaction of methanol carbonylation compared to highly porous catalysts. The conclusion is substantiated that the modification of the NiCl 2 /AC sample with tin additives provides an increase in the yield of the target product from 2 to 11 %, which may be caused by the formation of intermetallic phase crystallites Ni 3 Sn within NiCl 2 -Sn/AC (identified by XRD) under conditions of catalysis – adsorption/activation sites of CO molecules.

Carbonylation of Methanol Over Nickel-Copper Based Supported Catalysts

The results are reported concerning the production of methyl acetate in the halide-free vapor-phase methanol carbonylation (MC) over NiCl2–CuCl2 based catalysts on activated carbons and honeycomb cordierite supports. The formation of the MeOAc with the yield of 18% over nickel-copper chlorides on the BAC-A grade carbon support is shown to be facilitated by the optimal combination of the characteristics of the porous structure (mesopores with an average diameter of ~ 7 nm) and the surface acidity of the catalyst. 15% of MeOAc yield over NiCl2–CuCl2/cordierite, commensurate with the YMeOAc for NiCl2–CuCl2/AC, is achieved due to advantages of structured systems in comparison with the highly porous granular ones, including more efficient mass transfer and heat removal as well as the increased outputs per active components loadings. Using CuO–ZnO–NiO/Al2O3/cordierite (to generate CO as a carbonylation agent by MeOH decomposition) and NiCl2–CuCl2/AC(or cordierite) catalysts placed in series-connected flow-type reactors or in a single reactor with two different temperature zones provides producing methyl acetate in a carbon monoxide free gas feedstock with the MeOAc yields of 13–16.5% in “self-carbonylation” tandem process.

Dual-Ionically Bound Single-Site Rhodium on Porous Ionic Polymer Rivals Commercial Methanol Carbonylation Catalysts.

Novel porous polymers can serve as self-supporting solid carriers and provide abundant coordination or charged sites for single-site metals, and thus are emerging as advanced functional materials in heterogeneous catalysis for various transformations traditionally catalyzed by homogeneous systems. A brief overview of the development of this heterogenization given, including the recent advances regarding electrovalent bonds by employing charged supports represented by porous ionic polymers (PIPs), which is exemplified herein with a novel single-site Rh1 /PIP catalyst, featuring a new active site [Rh(CO)I3 ]2- dual-ionically bound onto a quaternary phosphonium cationic framework polymer, different from the single-ionically bound [Rh(CO)2 I2 ]- in previous studies. Such a unique metal configuration of Rh1 /PIP leads to excellent performance in vapor-phase methanol carbonylation, outperforming commercial homo- and heterogeneous catalysts.

A Novel NiCl<sub>2</sub>-CuCl<sub>2</sub>/HMOR Catalyst for Direct Vapor-Phase Carbonylation of Methanol

Direct vapor-phase methanol carbonylation, without any methyl iodide in the feed as a promoter, was carried out over NiCl2-CuCl2/HMOR catalysts. The results showed that NiCl2-CuCl2/HMOR catalysts exhibited high activity for methanol carbonylation. The optimum component of the composite catalyst was 5wt% NiCl2 and 15wt% CuCl2. In addition, the effects of reaction pressure and temperature on catalytic performance of 5%NiCl2-15%CuCl2/HMOR catalyst were investigated. It was revealed that methanol conversion of 84.2% and carbonylation selectivity of 73.5% could be obtained under the optimum reaction conditions of P=1.5MPa and T=623K.

Bifunctional Organorhodium Solid Acid Catalysts for Methanol Carbonylation

Robust, bifunctional catalysts comprising Rh(CO)(Xantphos) exchanged phosphotungstic acids of general formulas [Rh(CO)(Xantphos)]+n[H3–nPW12O40]n− have been synthesized over silica supports which exhibit tunable activity and selectivity toward direct vapor phase methanol carbonylation. The optimal Rh:acid ratio = 0.5, with higher rhodium concentrations increasing the selectivity to methyl acetate over dimethyl ether at the expense of lower acidity and poor activity. On-stream deactivation above 200 °C reflects Rh decomplexation and reduction to Rh metal, in conjunction with catalyst dehydration and loss of solid acidity because of undesired methyl acetate hydrolysis, but can be alleviated by water addition and lower temperature operation.

Particle growth and redispersion of monodisperse rhodium nanoparticles supported by porous carbon microspherules during catalyzing vapor phase methanol carbonylation

Monodisperse Rh nanoparticles mounted in the porous carbon microspherules were synthesized through the controlled carbonization of poly(vinylidene chloride) beads containing di-μ-chlorotetracarbonyldirhodium as Rh precursors. Rh nanoparticles were formed spontaneously and simultaneously with the evolution of carbon structures from the composite polymeric precursors. X-ray photoelectron spectroscopy (XPS) was used to detect the transformation of high valent Rh species to zero-valent Rh atoms. The dispersion state and particle size were characterized by EPMA and TEM in detail. The as-synthesized Rh nanoparticles were in the monodisperse state with the particle size of about 10 nm. Under catalytic vapor phase methanol carbonylation conditions, particle growth and redispersion take place through a mechanism involving the formation and transportation of Rh-containing volatile molecules. This is evidenced by the comparison of the dispersion state and particle size of the supported Rh nanoparticles before and after catalyzing vapor phase methanol carbonylation. It is clearly demonstrated that the Rh nanoparticles move to the support's surface and grow to about 30 nm after 50-h reaction on stream.

Deactivation of activated carbon supported nickel-palladium catalyst for vapor phase carbonylation of methanol

Vapor phase carbonylation of methanol was investigated over Ni-Pd/AC catalyst under the conditions of 260°C, 1.5 MPa, CO/CH 3OH/CH 3I(molar ratio)20/19/1, W/F=7.5 g cat·h·mol −1. The structure and surface property of the fresh and deactivated Ni-Pd/AC catalysts were characterized by BET specific surface area, Pyrolysis-FTIR (Py-FTIR) and XPS. It was found that the deactivation at the primary step appeared to be consistent with a strong adsorption of reaction products that plugged the catalyst pores and led to a diffusion limitation. With the proceeding of the reaction, the carbonylation active site Ni migrated gradually and enriched on the catalyst surface, resulting in easy carbon deposition, which enhanced the deactivation of the catalyst. Further investigation revealed that the carbon deposited on the catalyst surface has graphite structure or is similar to graphite structure.

Polymer-derived carbon-supported group VIII metals catalysts for vapor phase carbonylation of methanol

Porous carbon beads (CB) prepared by carbonizing poly(vinylidene chloride) were used to support group VIII metals for vapor phase carbonylation of methanol. Compared with other typical activated carbon (AC), many new properties were developed during synthesis and carbonization processes. Novel active centers were introduced on the surface by the presence of two heteroatoms (Si, O) from bentonite; the active centers are thermally stable and affect the final metals dispersion. The dispersion of supported metals on CB at different temperatures was characterized by X-ray photoelectron spectroscopy (XPS) and transmission electron microscopy (TEM). The thermally stable active centers enhance the stability of the supported metals particles. Three catalysts prepared on CB and two catalysts prepared on AC were tested in a fixed bed reactor. Activity and thermal stability of the catalysts were evaluated. CB presented excellent support performance. The second components such as Al, Zn, Sn and rare earth elements were introduced, Al and Zn are catalyst poisons, Sn and REE are catalyst promoters.

Support effects of nickel on activated carbon as a catalyst for vapor phase methanol carbonylation

Nickel supported on activated carbon can be used for the vapor phase carbonylation of methanol, producing methyl acetate and acetic acid as products. In contrast to previous reports, a strong influence of the support on the performance of the catalyst, in terms of both activity and stability, was observed in the current study. The effect appears to be related to the pore size distribution of the support. Catalysts prepared on large pore activated carbons are less active than catalysts prepared on smaller pore activated carbons but show no deactivation over time on stream. The mechanism of deactivation appears to be consistent with a strong adsorption of methanol and reaction products that plugs the catalyst pores and leads to increasingly strong diffusion limitations with time on stream.

Kinetic studies on vapor phase carbonylation of methanol to acetic acid over Rh/Ys catalyst

Kinetic studies on vapor phase carbonylation of methanol to acetic acid over Rh/Ys catalyst

Features of Carbon-supported Metal Catalysts for Vapor Phase Carbonylation of Methanol and Related Compounds.

Catalytic activities of active carbon (A.C.) supported group 8-10 metals catalysts for vapor phase carbonylation of methanol were found to be in the order as follows: Rh>Ir>Ni>Pd>Co>Ru>Fe. A plot of the relation between the catalytic activity and the affinity of the metals for halide ion displayed a volcano shape. The rate determining step of the reaction is discussed on the basis of this affinity.A variety of metal species of group 5-16, such as V, Cr, W, Mn, Re, Cu, Cd, Ga, Ge, Sn, Pb and Se, showed the catalytic activity in the vapor phase carbonylation of methanol, only when they were supported on A.C. Among them, tin and lead showed comparatively high activities.Over Ni/A.C. catalyst, methanol was first carbonylated directly to methyl acetate or via dimethyl ether, then carbonylated again to acetic anhydride and finally hydrolyzed quickly to acetic acid. Overall kinetics were explored to simulate product profile, based on the reaction network mentioned above.Vapor phase carbonylation was greatly enhanced by coexistence of hydrogen when the metal had a high affinity for halogen, whereas, it was inhibited over such metal having weak affinity.

Effect of metal loading sequence on the activity of Sn-Ni/C for methanol carbonylation

Abstract Sn-Ni/C catalysts for the carbonylation of methanol were prepared via incipient impregnation. The metals, Sn and Ni, were loaded on the activated carbon in various sequences for the examination of the order effects. The prepared catalysts were characterized by XRD, BET, TPD and ESCA. Activities of the catalysts were tested by means of vapor phase carbonylation of methanol at atmospheric pressure. Metal loading sequence was found to possess remarkable effects on the properties of the resulting catalysts.

Kinetics of Primary Reactions of Vapor-Phase Methanol Carbonylation on Sn-Ni/C Catalyst

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTKinetics of Primary Reactions of Vapor-Phase Methanol Carbonylation on Sn-Ni/C CatalystTuan-Chi Liu and Shwu-Jer ChiuCite this: Ind. Eng. Chem. Res. 1994, 33, 7, 1674–1679Publication Date (Print):July 1, 1994Publication History Published online1 May 2002Published inissue 1 July 1994https://doi.org/10.1021/ie00031a006RIGHTS & PERMISSIONSArticle Views326Altmetric-Citations6LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit PDF (1 MB) Get e-Alerts Get e-Alerts

Vapor-phase carbonylation of methanol on an active carbon supported iridium-catalyst

Iridium on active carbon (Ir/A.C.) is an effective catalyst for the vapor-phase carbonylation of methanol. In contrast to rhodium-catalysts the reaction rate is nearly independent of the partial pressure of the methyl iodide promoter and the methanolysis of an iridium-acetyl species has been found to determine the rate. Undesired methane formation accompanying the carbonylation is suggested to proceed via proteolysis of iridium-methyl species by methanol or water. Methyl chloride has been found to be a less effective promoter than methyl iodide.

Hydrogen effects on nickel-catalyzed vapor-phase methanol carbonylation

The influence of hydrogen on the reaction orders of CO and methanol, with respect to the formation of acyl compounds, methane, and dimethyl ether, was investigated. Although hydrogen-promoted methane formation, experiments with deuterium and methanol- d 1 (MeOD) clarified that the hydrogen of the methanol hydroxyl group is the exclusive hydrogen source of the CH 4 formation and that this reaction occurs at nickel centers, which are also involved in the acyl compound formation. Temperature-programmed reaction (TPR) and X-ray diffraction (XRD) experiments suggested that the hydrogen effect is caused by changes in the number of active sites and that neither methanol carbonylation nor methane formation proceeds at the larger nickel[0] crystallites detectable by XRD. Furthermore, it has been demonstrated that under certain reaction conditions, hydrogen can induce a remarkable deactivation of the catalyst by promoting nickel aggregation. A mechanism that accounts for the hydrogen effects has been postulated.

Redox cycle of metal-on-active carbon catalyst in the vapor phase carbonylation of methanol

Clarification was undertaken of the role of active carbon in metal supported on active carbon catalysts, which show high activities for methanol carbonylation. It was found that the reaction proceeded via a redox cycle of supported metals and that active carbon promoted the reduction step (in the case of nickel catalyst) and the oxidation step (in the case of palladium), respectively.

Influences of the surface modification of carbon supports on the nickel-catalyzed vapor phase carbonylation of methanol

The suitability of various carbonaceous materials, modified by oxidation and/or defunctionalization in the vapor phase methanol carbonylation, was inquired. In addition to a comparison of activities and their dependence on process time, the catalysts were characterized by carbon monoxide and methyl iodide chemisorption as well as by temperature programmed reaction, XRD and XPS. While oxidized and subsequently defunctionalized carbon-supported catalysts achieved good performances, surface-oxidized carbons have been shown to be unsuitable carriers.

Preparation of nickel-on-active carbon catalyst by CVD method for methanol carbonylation

The nickel on active carbon (Ni/A.C.) catalysts prepared by a simple chemical vapor deposition (CVD) method showed comparable catalytic activities for the vapor phase carbonylation of methanol to those of the catalysts prepared by impregnating A.C. with nickel nitrate and activating by hydrogen treatment. The CVD method was successfully applied to the in situ catalyst preparation.

Vapor-phase carbonylation of methanol over lead on active carbon catalyst

Lead supported on active carbon showed a catalytic activity for the vapor phase carbonylation of methanol under pressurized conditions in the presence of methyl iodide promoter.

Coordination chemistry of rhodium and iridium in constrained zeolite cavities: methanol carbonylation

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