Conversion Of Maleic Anhydride Research Articles

Construction of trifloaluminate ionic liquid catalyst on the silica surface dedicated for continuous flow Diels-Alder synthesis

Supported ionic liquid phases (SILP) are efficiently use for the construction of highly active, heterogeneous and recyclable catalysts. In this study, three strategies towards chemical immobilization of trifloaluminate ionic liquid catalyst into microporous/mesoporous silica support were investigated. The order of silica surface modification with trifloaluminate ILs components had crucial influence on the catalytic activity and stability which was tested in the model Diels-Alder reaction between isoprene and maleic anhydride in acetonitrile at room temperature. The best catalytic performance (maleic anhydride conversion > 97% in ten reaction cycles) was achieved for catalyst created through the synthesis of trifloaluminate ionic liquid in the first step with further bounding to the silica surface using 25 wt% of ionic liquid loading. The effective transformation of the Diels-Alder reaction to continuous flow synthesis led to 97% maleic anhydride conversion over 432 h with a TOF of 104.3 h−1 and significantly improved process sustainability.

Simulation study of reactive distillation process for synthesis of dimethyl maleate

Abstract Conventional dimethyl maleate (DMM) synthesis relies on the use of sulfuric acid as a catalyst which requires water washing and produces a large amount of wastewater that harms the environment. The use of this method is expensive since it involves numerous processes such as neutralization of sulfuric acid, washing with water, distillation etc. and the yield of dimethyl maleate is not very high. Reactive distillation integrates the two important industrial processes such as reaction and distillation into a single unit which shortens the overall process, reduces capital and operating costs, and maintains the reaction in a forward direction to enhance the conversion of maleic anhydride by continuously removing of the products. In this work, simulation study based on experimental investigation of reactive distillation process for the synthesis of dimethyl maleate was carried out using Aspen Plus V11. DZH strong cation exchange resin was used as catalyst for esterification reaction of maleic anhydride with methanol. A reactive section of column was packed with Katapak SP type packing loaded with DZH catalyst while non-reactive sections consist of wire gauze packing. In order to describe a reactive distillation process for synthesis of dimethyl maleate, RAD-FRAC equilibrium stage model was employed. The NRTL activity model and RK equation of state model were selected to describe vapor-liquid equilibrium of the system. The reliability of the developed simulated model was verified by validating the simulation results with the experimental ones. The effect of various design and operating parameters on the conversion of maleic anhydride and purity of dimethyl maleate has been studied. It was found that the optimal condition for RD, were as follow: total number of theoretical stages 17, rectifying stages 3, reactive stages 7, stripping stages 5, reflux ratio 0.25, operating pressure 0.1 MPa, reboiler duty 250 Cal/Sec, feed mole ratio 1:5. Under optimized condition the water formed as a results of esterification reaction was constantly removed from the reactive section of the column to maintain reaction balance, the conversion of maleic anhydride was 99.95 %, purity of dimethyl maleate achieved was 0.997 and the reactive distillation process was feasible to produce dimethyl maleate without any wastewater.

Low supported nickel-cobalt catalyst for hydrogenation of maleic anhydride

In order to prepare supported catalysts with low-metal loading, a series of NiCo/Clay catalysts were prepared and used in the hydrogenation of maleic anhydride. The hydrogenation reaction was carried out in a fixed-bed for 8 h with reaction pressure = 1 MPa, reaction temperature = 180 °C, molar ratio of H2: maleic anhydride = 50, WHSV = 2 h−1. Ni4Co1/Clay (loaded 3 wt%Ni and 0.75 wt%Co) can maintain no obvious catalyst deactivation within 8 h. The overall conversion of maleic anhydride is not less than 95 %, and the selectivity of succinic anhydride is up to 100 %. N2 adsorption–desorption characterization, X-ray diffraction, temperature-programmed reduction, temperature-programmed desorption, X-ray photoelectron spectroscopy and transmission electron microscopy were performed to verify the changes in catalyst morphology, active species, reduction performance and hydrogenation activity after adding Co as a promoter. With the addition of Co additive, the distribution of active sites on the carrier is more uniform, the grain size of active metal becomes smaller and the reduction temperature decreases. The addition of Co not only increased the active center of the catalyst but also effectively avoided the catalyst's deactivation.

Selective Hydrogenation of Maleic Anhydride to Succinic Anhydride in Liquid Phase over Ni-Cu/Al<SUB>2</SUB>O<SUB>3</SUB> Catalyst

A series of Ni-Cu/Al2O3 catalyst samples were prepared by the wetness impregnation method and characterized by N2 physisorption, H2 temperature-programmed reduction, H2 temperature-programmed desorption, X-ray diffraction, and CO temperature-programmed surface reaction. Their catalytic performance in the liquid phase hydrogenation of maleic anhydride was investigated. The results indicated that the particle size of nickel crystallites was reduced, and the nickel species was well dispersed. Then, the C=C hydrogenation activity was significantly improved when the catalyst was promoted by Cu. However, due to the interaction between Ni and Cu, the C=O hydrogenation was retarded. The combination of the above two factors led to high selectivity for succinic anhydride over 15%Ni-7%Cu/Al2O3 catalyst. The conversion of maleic anhydride and selectivity for succinic anhydride reached 100% under the reaction conditions of 5 MPa hydrogen pressure and 210 oC for 40 min.

A Highly Efficient and Selective Nickel/Clay Catalyst for Liquid Phase Hydrogenation of Maleic Anhydride to Succinic Anhydride

Three Ni-based catalysts with different clay as support were prepared and tested in the hydrogenation of maleic anhydride, among which Ni/clay1 showed best activity and selectivity. Over Ni/clay1 catalyst prepared by impregnation method, 97.14% conversion of maleic anhydride and 99.55% selectivity to succinic anhydride were obtained at 180 .deg. C under a pressure of 1 MPa. Catalytic activity was greatly influenced by the temperature and weighted hourly space velocity. Catalyst deactivation studies showed that this catalyst have a long life time, the yield of MA still higher than 90% even after a reaction time of 60 h. X-ray diffraction (XRD) and H{sub 2} temperature programmed reduction (TPR) were use to investigate the properties of the catalyst. XRD and TPR studies showed that Ni was present as Ni{sup 2+} on the support, which indicated that there was no elemental nickel (Ni{sup 0}) and Ni{sub 2}O{sub 3} in the unreduced samples. The formation of Ni was strong impact on catalytic activity.

Selective hydrogenation of maleic anhydride to succinic anhydride catalyzed by metallic nickel catalysts

Maleic anhydride was selectively hydrogenated to succinic anhydride over metallic nickel catalysts, such as Raney Ni and Ni nanoparticles, in liquid phase at reaction temperature lower than 130°C. When the Raney Ni catalyst in solvents with different polarities catalyzed the hydrogenation of maleic anhydride to succinic anhydride, the solvent with high polarity favored the hydrogenation of maleic anhydride to succinic anhydride as compared to that with low polarity. When the hydrogenation reaction was catalyzed by Raney Ni catalyst at 100°C and H2 pressure of 2.5MPa for 360min in acetic anhydride, the conversion of maleic anhydride and the selectivity of succinic anhydride were 99.6% and 100%, respectively. In solvent-free reaction system, γ-butyrolactone as a byproduct with the maximum selectivity of 14.8% was produced at 130°C. All of the Ni nanoparticles with average diameters ranging from 8 to 313nm showed higher catalytic activity than Raney Ni in liquid phase hydrogenation of maleic anhydride to succinic anhydride. When the Ni nanoparticles with an average diameter of 8nm were used as the catalysts in the liquid phase hydrogenation at 80°C and 2MPa of H2 for 150min and the weight ratio of catalyst to maleic anhydride was 1:100, the conversion of maleic anhydride and the selectivity of succinic anhydride were 99.8% and 100%, respectively. The small particle size and the polycrystalline structure of Ni nanoparticles played important roles in the liquid phase selective hydrogenation of maleic anhydride to succinic anhydride.

Influence of metal particle size on the hydrogenation of maleic anhydride over Pd/C catalysts in scCO 2

Hydrogenation of maleic anhydride (MAH) with Pd/C catalysts in supercritical carbon dioxide (scCO 2) was investigated. The selectivity for γ-butyrolactone (GBL) reached 97.3% in scCO 2 at 100% conversion of MAH, which was notably higher than that of 77.4% obtained in organic solvent of ethylene glycol dimethyl ether (EGDME). The particle size of Pd exhibited large influence on the reaction rate and selectivity of GBL. Higher selectivity of GBL was obtained with Pd/C catalyst of smaller Pd particle size, and the rate of GBL selectivity increase as a function of CO 2 pressure was found to be significantly correlated with Pd particle size.

Synthesis of tetrahydrofuran from maleic anhydride on Cu–ZnO–ZrO2/H-Y bifunctional catalysts

Abstract A series of bifunctional Cu–ZnO–ZrO2/H-Y catalysts of different compositions were prepared by coprecipitating sedimentation method and were characterized by surface area and XRD analyses. The catalytic performance in synthesis of tetrahydrofuran was evaluated and optimized in a three-phase slurry batch reactor. The experimental results showed that the appropriate ratio of Cu/ZnO in the hydrogenation catalyst was 50/45, for which the conversion of maleic anhydride (MA) and selectivity of tetrahydrofuran (THF) reached 100% and 46%, respectively, at 50 bar and 493 K after 6 h of operation. Also, according to these results, it was demonstrated that the incorporation of zirconium oxide in the catalyst formulation enhanced the catalytic activity, and tetrahydrofuran selectivity was increased to 55%. Ultimately, it was concluded that the bifunctional catalyst of Cu–ZnO–ZrO2/H-Y was an appropriate catalyst to produce THF from MA with high activity, selectivity and stability.

Preparation and mechanical properties of poly(vinyl chloride)/bamboo flour composites with a novel block copolymer as a coupling agent

AbstractTo improve the interfacial adhesion between poly(vinyl chloride) (PVC) and bamboo flour in PVC/bamboo flour composites, a novel coupling agent, poly(styrene‐co‐maleic anhydride)‐block‐poly(styrene‐co‐acrylonitrile) {P[(SMA)‐b‐(SAN)]}, was synthesized through living free‐radical polymerization in a one‐pot reaction. P[(SMA)‐b‐(SAN)] was synthesized by a nitroxide‐mediated polymerization technique in the presence of 2,2,6,6‐tetramethylpiperidin‐l‐oxyl with azobisisobutyronitrile. The conversion of maleic anhydride (>99%) and styrene (>65%) was relatively high and yielded P[(SMA)‐b‐(SAN)] with a narrow molecular weight distribution (weight‐average molecular weight/number‐average molecular weight <1.38). PVC was blended with bamboo flours in the presence of the synthesized coupling agent with a two‐roll mill. P[(SMA)‐b‐(SAN)] was added to the PVC matrix at a concentration of 55 or 20 wt %. As the content of P[(SMA)‐b‐(SAN)] in the wood–polymer composite increased, improved morphological and mechanical behaviors were observed. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008

Gas Phase Hydrogenation of Maleic Anhydride to γ-Butyrolactone by Cu–Zn–Ce Catalyst in the Presence of n-Butanol

A series of Cu–Zn–Ce catalysts were prepared by coprecipitation method and characterized by X-ray diffraction, X-ray photoelectron spectroscopy, temperature programmed reduction, and N2 adsorption. The catalytic activities of the Cu–Zn–Ce catalysts in gas phase hydrogenation of maleic anhydride in the presence of n-butanol were studied at 220–280 °C and 1 MPa. The conversion of maleic anhydride was more than 97%. After reduction, CuO species present in the calcined Cu–Zn–Ce catalysts were converted to metallic copper (Cu°). The presence of ZnO in the Cu–Zn–Ce catalysts was beneficial to stabilizing the catalytic activity in maleic anhydride hydrogenation to γ-butyrolactone. At the same time, n-butanol was dehydrogenated to butyl aldehyde, then to butyl butyrate via reactions, such as disproportionation and esterification. Cu–Zn–Ce catalysts are beneficial to the H2 compensation in the coupling process of hydrogenation and dehydrogenation.

Gas phase hydrogenation of maleic anhydride to tetrahydrofuran by Cu/ZnO/TiO2 catalysts in the presence of n-butanol

Abstract Cu/ZnO/TiO 2 catalysts were prepared via the coprecipitation method. The catalysts were characterized by X-ray diffraction, X-ray photoelectron spectrometry, temperature programmed reduction, and N 2 adsorption. The catalytic activity of Cu/ZnO/TiO 2 catalyst in gas phase hydrogenation of maleic anhydride in the presence of n -butanol was studied at 235–280 °C and 1 MPa. The conversion of maleic anhydride was more than 95.7% and the selectivity of tetrahydrofuran was up to 92.7%. At the same time, n -butanol was converted to butyraldehyde and butyl butyrate via reactions, namely, dehydrogenation, disproportionation, and esterification. There were two kinds of CuO species present in the calcined Cu/ZnO/TiO 2 catalysts. At a lower copper content, the CuO species strongly interacted with ZnO and TiO 2 ; at a higher copper content, both the surface-anchored and bulk CuO species were present. The metallic copper (CuO) produced by the reduction of the surface-anchored CuO species favored the deep hydrogenation of maleic anhydride to tetrahydrofuran. The deep hydrogenation activity of Cu/ZnO/TiO 2 catalyst increased with the decrease of crystallite sizes of CuO and the increase of microstrain values. Compensations of reaction heat and H 2 in the coupling reaction of maleic anhydride hydrogenation and n -butanol dehydrogenation were distinct.

The hydrogenation of maleic anhydride to γ-butyrolactone using mixed metal oxide catalysts in a batch-type reactor

An improved catalytic hydrogenation process for converting maleic anhydride and/or succinic anhydride to γ-butyrolactone uses a novel selective catalyst in a liquid phase operating at high pressure batch-type reactor. The catalysts are composed of palladium, molybdenum and nickel on a silica support of high surface area. This multi-component mixed metal oxide catalyst system in a batch-type reactor is found to be suitable for the hydrogenation of maleic anhydride selectively to γ-butyrolactone. The effects of temperature, pressure and catalyst to reactant ratio are investigated in order to optimize the reaction conditions for better activity, yield and selectivity. A reaction temperature of 220 to 260 °C and pressure of 60 to 80 atm were afforded, the mixed metal oxide catalyst containing nickel, palladium and molybdenum oxide is shown almost 100% conversion of maleic anhydride within 120 min and 56–96% yield of γ-butyrolactone. The hydrogenation of maleic anhydride using this catalyst is not observed by-products and the selectivity of γ-butyrolactone is very high.

Study on esterification of acrylic phenolic resin by maleic anhydride and photocrosslinking properties of the alkali‐soluble product

AbstractAn alkali‐soluble, photocrosslinkable polymer was synthesized by esterification of OH groups of acrylic phenolic resin with maleic anhydride. The OH groups were formed by the ring‐opening reaction of epoxy groups of epoxy phenolic resin with acrylic acid. The esterification conditions were studied. The results showed that it is better to use tetramethyl ammonium bromide as catalyst than N,N‐dimethylbenzylamine. The conversion of maleic anhydride in acetone can reach about 80% at 56°C for 4 h. The purified product was characterized by IR, DSC, and TGA. The product containing acrylate and maleic acid monoester groups, above a certain content, can be dissolved in 1% Na2CO3 solution. The photocrosslinkable properties of the product were investigated through selection of photoinitiator, accelarator, crosslinkable diluent monomer, etc. The acrylate and maleic acid monoester group‐containing phenolic resin exhibited very good photocrosslinking behavior, since it contains double bonds from both acrylate groups and maleic acid monoester groups. The activity of photoinitiator decreases in the order: isopropylthioanthraquinone > benzoin ethyl ether (BE) > anthraquinone (AQ) > benzophenone > Michel ketone (MK) > 2,2‐diethoxyacetophenone. The combination of some photoinitiators showed synergistic effects. The order of increasing activity for the accelerator is as follows: MK > ethyl p‐(dimethylamino)benzoate > N,N‐dimethylaniline > triethanolamine. The optimum diluent monomer is trimethylolpropane trimethacrylate. The gel content of the mixture of the resin and trimethylolpropane trimethacrylate could reach 85% using the combined photoinitiators of BE and AQ under UV exposure for 120 s. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 98: 1607–1614, 2005

Gas-phase hydrogenation of maleic anhydride to butyric acid over Cu/TiO 2/γ-Al 2O 3 catalyst promoted by Pd

The promoter effect of palladium on the Cu/TiO 2/γ-Al 2O 3 catalyst was investigated for the gas-phase selective hydrogenation of maleic anhydride to butyric acid at atmospheric pressure. The results show that Pd is added rarely into the Cu/TiO 2/γ-Al 2O 3 catalyst for the hydrogenation of maleic anhydride, the higher selectivity to butyric acid can be obtained. In the absence of Pd (or Cu) in the Cu–Pd/TiO 2/γ-Al 2O 3 catalyst, the selectivity to butyric acid (BA) is nearly zero. Using the Cu–Pd/TiO 2/γ-Al 2O 3 (Pd/Cu=3/100 (atom)) catalyst, 56.2% selectivity to BA and 100% conversion of maleic anhydride were obtained at 280 °C.

Maleic anhydride conversion by V-P-O catalysts

The vapor phase conversion of maleic anhydride was studied using two model vanadium-phosphorus-oxygen (V-P-O) catalysts, β-VOPO 4 and (VO) 2P 2O 7, and a series of industrial-type catalysts having P-to-V ratios of 0.9, 1.0, 1.1 and 1.2. Maleic anhydride was fed directly to an integral flow reactor using a molten maleic anhydride saturator system. Direct evidence for the combustion of maleic anhydride has been observed with the simultaneous production of maleic acid. The conversion of maleic anhydride increased with temperature, oxygen partial pressure, and residence time. The incorporation of “excess” phosphorus in industrial catalysts suppressed maleic anhydride combustion by stabilizing the (VO) 2P 2O 7 phase.