Dehydrogenation Of Isopropanol Research Articles

Optimizing The Net Energy of Acetone Production using The Isopropyl Alcohol Dehydrogenation Process

In order to reduce the dependence on fossil fuels, acetone has emerged as an important platform chemical for various industrial applications. Acetone can be efficiently produced through the dehydrogenation of isopropanol, using metal-based catalysts with high activity and selectivity. The technology for this acetone production was simulated using Aspen HYSYS software, with operating parameters based on the reaction dynamics model for isopropanol dehydrogenation. This study evaluated the modification of the dehydrogenation process to improve energy efficiency by optimizing the heat transfer unit. The product heat leaving the reactor will be cooled in a heat exchanger and the heat is used to increase the heat from the mixer output, this is designed to utilize the process output energy, thus utilizing the heat exchanger as a cooler for the reactor output, thereby reducing additional energy consumption and improving the overall process sustainability. The modification includes increasing the acetone production yield and energy efficiency in the heat transfer unit to reduce energy consumption from 10.9296 MMBtu/h to 7.7431 MMBtu/h by utilizing the heat exchanger as a cooler for the reactor output back and at the same time a heater for the mixer output as a process optimization. Copyright © 2024 by Authors, Published by Universitas Diponegoro and BCREC Publishing Group. This is an open access article under the CC BY-SA License (https://creativecommons.org/licenses/by-sa/4.0).

High Selective Electrocatalysis Dehydrogenation of Isopropanol to Acetone with Cobenefits: Carboxylic Acids Coproduction

High Selective Electrocatalysis Dehydrogenation of Isopropanol to Acetone with Cobenefits: Carboxylic Acids Coproduction

The Electrochemical Acetone/Isopropanol Hydrogenation Cycle: Full-Cell Performance of the Electrochemical Dehydrogenation of Isopropanol

Molecular hydrogen has exceptionally high gravimetric energy density but low volumetric energy density at ambient conditions. This discrepancy requires technical measures to increase its volumetric energy density for widespread hydrogen applications. Compressed hydrogen and liquified hydrogen are the most established hydrogen storage technologies. In addition, thermocatalytic liquid organic hydrogen carriers (LOHC) have drawn significant attention in the last decade.[1] LOHC couples consist of a hydrogen-lean and a hydrogen-rich form that can be reversibly converted into each other on demand. So far, only a few approaches adapted this hydrogen storage concept to electrochemistry. However, there is strong interest in electrochemical liquid organic hydrogen carriers (EC-LOHC) as electrochemical processes offer significant advantages like flexible operation, device size, scalability, and system simplicity.[2] This contribution demonstrates the concept of acetone/isopropanol as an electrochemical liquid organic hydrogen carrier focusing on the electrochemical dehydrogenation of isopropanol in a polymer electrolyte membrane electrode assembly (PEM-MEA) setup. The isopropanol oxidation at a PtRu electrode shows two distinct oxidation peaks at 0.18 V vs. RHE and 0.75 V vs. RHE, whereby the first oxidation peak is associated with a selective oxidation of isopropanol to acetone, electrons and protons.[3] The produced protons travel from the PtRu anode through the PEM and recombine with the electrons at the Pt cathode to form hydrogen. Therewith, this configuration is an electrolysis cell that produces hydrogen out of isopropanol upon polarization above the reversible cell potential.The study investigates the influence of acetone/isopropanol concentrations, temperature, and flow rates on the I-V characteristics of the electrochemical dehydrogenation of isopropanol at voltages below 0.35 V, revealing its possible potential as EC-LOHC.

Enhancing reductive conversion of levulinic acid and levulinates to γ-valerolactone: Role of oxygen vacancy in MnOx catalysts

Oxygen vacancies (Ov) in metal oxides play a crucial role in modifying the electronic and acidic properties of catalysts, thereby influencing their catalytic activity. This study explores the impact of Ov in MnOx catalysts on their acidic and catalytic properties for the Meerwein–Ponndorf–Verley reduction of levulinic acid (LA) and levulinate to γ-valerolactone (GVL). Various characterization techniques demonstrate that surface Ov significantly modulate the acidic properties of MnOx catalysts, positively correlating with Lewis/Brønsted acid ratio and GVL yield. In situ DRIFTS and DFT calculations further unveil the reaction mechanism, revealing that Ov facilitate the activation and dehydrogenation of isopropanol and subsequent hydrogen transfer and hydrogenation of LA, leading to enhanced GVL production. These insights underscore the pivotal role of Ov in MnOx catalysts for the efficient conversion of LA to GVL, highlighting their importance in improving catalytic performance.

Ring–Opening Mechanism of O‐heterocycles into α,ω‐Diols over Ni−La(OH)3: C−O Bond Hydrogenolysis of THFA to 1,5‐Pentanediol as a Case Study

AbstractThe elucidation of the ring–opening reaction mechanism is a critical step towards improving the catalytic performance for the conversion of biomass into value–added chemicals. Herein, we focused on the stepwise C−O bond hydrogenolysis mechanism of oxygen–containing heterocycles (O‐heterocycles) into α,ω‐diols, in particular THFA to 1,5‐PeD, over selective Ni−La(OH)3 in hydrogen–donor isopropanol. A mechanistic study was carried out on a structurally well–defined Ni−La(OH)3, where the mechanism was elucidated using a combination of kinetic and 13C NMR isotope labeling experiments. It was suggested that both Ni nanoparticles and La(OH)3 support play a critical role in the reaction mechanism, where basic hydroxide species of the support initially deprotonate the CH2OH and −OH modified furan, tetrahydrofuran and tetrahydropyran rings, adsorbing them chemically on the catalyst surface. This step is followed by a direct hydride attack on the second carbon atom of these rings, which is proposed to be the key step for ring cleavage, as indicated by the increased deuteration at this position. In addition to the direct hydrogenolysis using gaseous H2, it is assumed that a catalytic transfer hydrogenolysis reaction (CTH) reaction of THFA is proposed to proceed via the dehydrogenation of isopropanol over isolated Ni species, forming hydrogen species that can be adsorbed on the Ni surface or desorb as H2 molecules.

Kinetic pathways of sub-bandgap induced electron transfer in Ag/TiO2 and the effect on isopropanol dehydrogenation under gaseous conditions.

Electron transfer and its kinetics play a major role in the photocatalysis of metal/semiconductor systems. Using in situ photoconductances, in situ photoabsorption, and photoinduced spectroscopic techniques, the present research aimed to gain a deep insight into electron transfer pathways and their kinetics for Ag/TiO2 systems under sub-bandgap light illumination and gaseous conditions. The results revealed that electrons generated in TiO2 can transfer to Ag nanoparticles at fast rates, and plasmon-generated electrons in Ag nanoparticles can also transfer to TiO2. However, it was found that plasmon-assisted hot electron transfer efficiency is much lower than the electron transition from the valence band to the conduction band of TiO2. Rather than plasmonic active spots, the results showed that Ag nanoparticles acted as co-catalyst sites bridging electron transfer to recombination in a methanol-containing N2 atmosphere. As a result, photocatalytic isopropanol dehydrogenation was decreased. Independent of Ag decorations, it was also indicated that isopropanol dehydrogenation mainly occurred over TiO2 surfaces; therefore, Ag nanoparticles did not increase photocatalytic activities. Our results may provide a different viewpoint on sub-bandgap light-induced Ag/TiO2 photocatalysis under gaseous conditions; this may also facilitate the understanding of the photocatalytic mechanism of metal/semiconductor systems.

A Theoretical Study on the Mechanisms Involved in Catalytic Dehydrogenation and Dehydration of Isopropanol on SrTiO3.

The dehydrogenation and dehydration of isopropanol on the SrO and TiO2 terminated surfaces, of the SrTiO3 perovskite, is addressed by periodic DFT calculations in order to shed light on the involved mechanisms. The results show that the dehydrogenation occurs through a mechanism involving the dissociative adsorption of the alcohol on the SrO terminated surface, followed the nucleophilic attack of a hydride species on the previously adsorbed hydrogen atom to form molecular hydrogen and the corresponding carbonyl compound. The dehydration instead occurs by the molecular adsorption of the alcohol on the TiO2 terminated surface, followed by various possible E1 elimination pathways leading to the formation of the corresponding alkene and a water molecule. The article reports a thorough study on the involved mechanisms, including identification of the transition states and intermediates along the reaction paths, and evaluation of the respective activation barriers, as well. Thus, this article provides significant insights about the mechanisms of dehydrogenation and dehydration of isopropanol on the SrTiO3 , not reported earlier in literature. The calculated barrier energies are in good agreement with experimental values.

Construction of modularized catalytic system for transfer hydrogenation: Promotion effect of hydrogen bonds

The construction of enzyme-mimicking catalysts is a crucial route for achieving green chemical transformations; however, integrating multiple sites into one catalyst is challenging. Herein, a facile method is reported to combine different active sites by constructing a modularized catalytic system. A modularized catalytic system composed of covalent organic frameworks (COFs) and Cu2Cr2O5 exhibits remarkable efficiency in the transfer hydrogenation of cinnamaldehyde, with a selectivity of over 99% towards cinnamyl alcohol, surpassing the reaction rate of Cu2Cr2O5 by more than fourfold. The results of the mechanistic study and density functional theory calculations suggest that the enhanced activity of the modularized catalytic system is derived from the hydrogen bonds between the COFs and isopropyl alcohol, which promote isopropyl alcohol dehydrogenation and hydride transfer. In addition, the modularized catalytic system is efficient for various saturated and unsaturated aldehydes and could be replaced by different submodules. This study demonstrates the efficiency of a modularized catalytic system for mimicking the functions of enzymes in catalysis.

Preparation by two simple methods and characterization of Ni3N and use in the hydrogenation of isopropanol

The catalytic dehydrogenation of isopropanol is an important area of the catalytic process to produce fine chemicals and has important applications in heat pumps, fuel cells, and acetone production. Thereby, the catalytic liquid-phase dehydrogenation of isopropanol has gained attention over the last decades and has used a large variety of homogeneous and heterogeneous catalysts. In this paper, nickel nitride (Ni3N) nanoparticles, having a cubic structure, were successfully synthesized in simple and efficient methods either from nickel oxide or from nickel complex. The morphological and structural analyses of the obtained nanoparticles were performed by using powder X-ray diffraction (XRD) and scanning electron microscopy with energy-dispersive X-ray spectroscopy (SEM/EDX). At room temperature and under atmospheric pressure, the dehydrogenation test of isopropanol, using nickel nitride as a catalyst, revealed very high activity and better Hydrogen production.

Boosting photocatalytic synchronous production of H2 coupled with acetone over Co doped Cu3P quantum dots/ZnIn2S4 nanosheets p-n nanojunction

Photocatalysis provides a new way for synchronous H2 production and organic synthesis at normal temperature and pressure, usually, water and organic substrate function as sources of hydrogen protons and organic products, which are complex and limited by two half-reactions. Employing alcohols as reaction substrates to simultaneously produce H2 and valuable organics in a redox cycle is worthy studying, to which catalyst design at atomic level holds the key. In this paper, Co elements doped Cu3P (CoCuP) quantum dots (QDs) are prepared and coupled with ZnIn2S4 (ZIS) nanosheets to form a 0D/2D p-n nanojunction which can effectively boost aliphatic and aromatic alcohols activation to simultaneously produce H2 and corresponding ketones (or aldehydes). The optimal CoCuP/ZIS composite demonstrated the highest activity for dehydrogenation of isopropanol to acetone (17.77 mmol⋅g−1⋅h−1) and H2 (26.8 mmol⋅g−1⋅h−1), which was 2.40 and 1.63 times higher than that of Cu3P/ZIS composite, respectively. Mechanistic investigations revealed that such high-performance originated from the accelerated electron transfer of the formed p-n junction and the thermodynamic optimization caused by the Co dopant which was the active site of oxydehydrogenation as a prerequisite step for isopropanol oxidation over the surface of the CoCuP/ZIS composite. Besides that, coupling of the CoCuP QDs can lower the dehydrogenation activation energy of isopropanol to form a key radical intermediate of (CH3)2CHO* for improving the activity of simultaneous production of H2 and acetone. This strategy provides an overall reaction strategy to obtain two meaningful products (H2 and ketones (or aldehydes)) and deeply explores the integrated redox reaction of alcohol as substrate for high solar-chemical energy conversion.

Influence of the activation method on the activity of the nickel catalyst

<p>The results of a comparative analysis of the influence of the activation method on the catalytic properties of a nickel diatomaceous earth catalyst during the conversion of isopropyl alcohol to acetone are presented. Studies of the activity of the catalyst in the reaction of gas-phase dehydrogenation of isopropyl alcohol were carried out on a flow-type laboratory installation at a temperature of 150-350ºC. The mechanical activation of the nickel diatomaceous earth catalyst was carried out in a planetary mill. Traditional activation included pre-heat treatment of nickel diatomaceous earth catalyst in an atmosphere of O<sub>2</sub> and H<sub>2</sub> at 250°C; IR radiation was carried out using an incandescent lamp. It is shown that the nature of the activator determines the features of the formed surface nickel complexes. The activity of samples of the nickel diatomaceous earth catalyst subjected to activation by thermal reduction and thermal oxidation, as well as IR irradiation, testified to the low efficiency of these methods. A comparison of the activity of industrial nickel diatomaceous earth catalyst samples subjected to different activation methods showed that processing of samples by thermal reduction and thermal oxidation slightly increases the yield of acetone. In contrast, the original catalyst's IR irradiation and mechanical activation decreased its activity. Thus, thermal reduction and oxidation methods are promising for further research to increase the industrial nickel diatomaceous earth catalyst activity in dehydrogenating isopropyl alcohol into acetone. </p>

DEPENDENCE OF ACTIVITY OF BINARY Mo-V-O CATALYSTS IN THE REACTION OF DEHYDROGENATION AND OXIDATION OF ISOPROPYL ALCOHOL ON ACIDIC SURFACE PROPERTIES

The reaction of dehydrogenation and oxidative dehydrogenation of isopropyl alcohol on molybdenum-vanadium oxide catalysts has been studied. It found that the dependences of isopropyl alcohol conversion and propylene yields on the atomic ratio of molybdenum to vanadium in reaction of dehydrogenation of isopropyl alcohol have the form of a curve with two maxima on samples Mo-V=2-8 and Mo-V=6-4. To characterize the acidic properties of the surface of molybdenum-vanadium oxide catalysts, their activity in the reaction of butene-1 isomerization into butenes-2 was also studied. It showed that on molybdenum-vanadium catalysts the dependence of the yield of 2-butenes on the ratio of molybdenum to vanadium also had the form of a curve with two maxima. The activities of molybdenumvanadium oxide catalysts were compared with their acidic properties. It revealed that on binary molybdenum-vanadium oxide catalysts in the reaction of isopropyl alcohol dehydrogenation the increase of surface acidity led to the increase in acetone yield and the decrease in propylene yield. In the reaction of oxidative dehydrogenation of isopropyl alcohol, the increase in surface acidity led to the increase in acetone yield, while propylene yield practically did not change.

A Lewis acid-base paired InBO3 catalyst: synthesis and high selectivity for isopropanol dehydrogenation.

Whilst metal borates are well known as optical materials, their potential in solid catalysis has been less investigated. The calcite structured InBO3 was selected as the target borate and was prepared using a solvothermal method. High-resolution transmission electron microscopy and powder X-ray diffraction prove that the material has a nanoparticle morphology with an average size ∼50 nm and high crystallinity. Intrinsic surface oxygen vacancies, which are beneficial to catalysis, were detected using X-ray photoelectron spectroscopy. Lewis acidity and basicity were both observed using NH3-/CO2-temperature-programmed desorption experiments, and the total acid and base amounts were found to be 46.6 and 123.8 μmol g-1, respectively. Catalytic dehydration and dehydrogenation reactions for isopropanol at elevated temperatures were conducted in a fixed bed reactor to evaluate the catalytic performance of InBO3. InBO3 exhibits a high conversion rate (>90.5%) and, most importantly, a high dehydrogenation selectivity (acetone selectivity >92.5%), whilst the optimal acetone yield achieved was 121.3 mmol h-1 g-1cat at 350 °C. This study on InBO3 strongly suggests that metal borates have promising applications in heterogeneous catalysis.

Automated MUltiscale simulation environment.

Multiscale techniques integrating detailed atomistic information on materials and reactions to predict the performance of heterogeneous catalytic full-scale reactors have been suggested but lack seamless implementation. The largest challenges in the multiscale modeling of reactors can be grouped into two main categories: catalytic complexity and the difference between time and length scales of chemical and transport phenomena. Here we introduce the Automated MUltiscale Simulation Environment AMUSE, a workflow that starts from Density Functional Theory (DFT) data, automates the analysis of the reaction networks through graph theory, prepares it for microkinetic modeling, and subsequently integrates the results into a standard open-source Computational Fluid Dynamics (CFD) code. We demonstrate the capabilities of AMUSE by applying it to the unimolecular iso-propanol dehydrogenation reaction and then, increasing the complexity, to the pre-commercial Pd/In2O3 catalyst employed for the CO2 hydrogenation to methanol. The results show that AMUSE allows the computational investigation of heterogeneous catalytic reactions in a comprehensive way, providing essential information for catalyst design from the atomistic to the reactor scale level.

Selective hydrodeoxygenation of 5-hydroxymethylfurfural (HMF) to 2,5-dimethylfuran (DMF) over carbon supported copper catalysts using isopropyl alcohol as a hydrogen donor

Selective hydrodeoxygenation (HDO) of 5-hydroxymethylfurfural to 2,5-dimethylfuran is of great importance. We reveal a simple pathway for green and efficient HDO using readily available copper with in-situ hydrogen generation. A highly dispersed Cu/PBSAC catalyst consisting of small metallic Cu0 nanoparticles carries out isopropyl alcohol (IPA) dehydrogenation and subsequent HDO of HMF. Density functional theory calculations reveal that the dehydrogenation of IPA is more favorable on Cu(211) with a lower energy barrier of ~0.6 eV. This facet exists in a higher ratio on nanosized catalysts. Batch reactions using Cu/PBSAC at 190 °C exhibited 91.9% HMF conversion and 71.7% DMF selectivity in 6 hr, and > 96% DMF yield in 10 hr. The mechanical strength of the carbon support is ideal for continuous processing for increased productivity; we demonstrate a > 90% DMF yield at 1/WHSV of 2.4 hr. The process demonstrated here can be integrated with upstream HMF separation utilizing carbon adsorbents.

Efficient Cu/FeOx catalyst with developed structure for catalytic transfer hydrogenation of furfural

Design of efficient and easy-recycling copper catalysts for furfural hydrogenation provides alternative approaches for high-value added chemicals and fuel. In this work, the catalytic transfer hydrogenation of furfural was catalyzed by magnetic Cu/FeOx catalysts via sol–gel method to produce 2-methylfuran with high yield. Homogeneous Cu-Fe-Ox composition could be constructed in the calcined precursor. The growth and evolution of metal centers were modulated and monitored during thermal treatments. The synergy between CuO and FeOx rationally affected the reducibility of the catalyst precursors. After the deliberate two-step-thermal activation, CuO was readily reduced and extruded from FeOx host matrix via phase segregation to give fine Cu particles fastened by FeOx supporting layers. Both experiments and simulation explicitly confirmed the facile isopropanol dehydrogenation to donate hydrogen via small Cu clusters. The dehydroxylation pathway was preferentially happened on furfuryl alcohol with lower activation energy.

Iridium-Catalyzed Dehydrogenation in a Continuous Flow Reactor for Practical On-Board Hydrogen Generation From Liquid Organic Hydrogen Carriers.

To enable the large‐scale use of hydrogen fuel cells for mobility applications, convenient methods for on‐board hydrogen storage and release are required. A promising approach is liquid organic hydrogen carriers (LOHCs), since these are safe, available on a large scale, and compatible with existing refueling infrastructure. Usually, LOHC dehydrogenation is carried out in batch‐type reactors by transition metals and their complexes and suffers from slow H2 release kinetics and/or inability to reach high energy density by weight, owing to low conversion or the need to dilute the reaction mixture. In this study, a continuous flow reactor is used in combination with a heterogenized iridium pincer complex, which enables a tremendous increase in LOHC dehydrogenation rates. Thus, dehydrogenation of isopropanol is performed in a regime that, in terms of gravimetric energy density, hydrogen generation rate, and precious metal content, is potentially compatible with applications in a fuel‐cell powered car.

Insights into the Role of Dual-Interfacial Sites in Cu/ZrO2 Catalysts in 5-HMF Hydrogenolysis with Isopropanol.

In this work, we synthesized a series of Cu/ZrO2 catalysts with tunable Vo-Cu0 (oxygen vacancy adjacent to Cu metal) and VZr-Cuδ+ (zirconium vacancy adjacent to electron-deficient Cu species) dual-interface sites and investigated the role of the dual-interface sites in the 5-hydroxymethylfurfural (5-HMF) hydrogenolysis reaction with isopropanol as the hydrogen source. By combining a series of in situ infrared characterization and catalytic performance analysis, it is identified that Vo-Cu0 interface sites were responsible for activating isopropanol dehydrogenation and C═O dissociation of 5-HMF, while the VZr-Cuδ+ interface sites were responsible for the dehydroxylation of an intermediate product 5-methyl-2-furfuryl alcohol (5-MFA). Specifically, C-OH was first deprotonated on the VZr at the VZr-Cuδ+ interface site to reduce the activation energy of 5-MFA dehydroxylation and then adjacent Cuδ+ promoted the dissociation of the C-O bond by enhancing the adsorption energy while elongating the C-O bond, as confirmed by the density functional theory calculations. Because the dual-interface sites provided separate sites for activating intermediate products and reactants, the coupling reaction caused by competitive adsorption is thus well avoided. Therefore, the optimized Cu/ZrO2 catalyst with the most VZr-Cuδ+ and moderate Vo-Cu0 sites exhibited 98.4% of 2,5-dimethylfuran yield under the conditions of 180 °C and self-vapor pressure.

MATHEMATICAL DESCRIPTION FOR THE OXIDATIVE DEHYDROGENATION OF ISOPROPANOL TO ACETONE

The paper presents the results of the development of the complete mathematical model for the oxidative dehydrogenation of isopropanol to acetone on the metal-zeolite catalyst – CuPd-mordenite. Using the kinetic model of this process have been chosen the optimal type of reactor. Have been identified the most significant physicochemical phenomena significantly affect to the process. The mathematical description of this process consists of the heat balance equation, as well as an equation that takes into account the pressure drop in the system at the gas mixture moving through a fixed-bed catalyst

A novel study on CHEMCAD simulation of isopropyl alcohol dehydrogenation process development

Acetone is a product which is obtained via several processes. It is produced mainly by cumene hydroperoxide process. As an alternative process, acetone is obtained by isopropyl alcohol (IPA) dehydrogenation. The conversion of IPA to acetone is an endothermic gas-phase reaction which produces hydrogen as a byproduct. The process consists of an equilibrium reactor or kinetic reactor (EREA), a distillation column (SCDS), and a flash tank. As the fresh feed, liquid-phase IPA, combined with a recycle stream which contains slight amount of unseparated acetone, is vaporized and given into the equilibrium reactor. Reactor effluent is then cooled by two heat exchangers and pressurized by a compressor until unreacted IPA and formed acetone are liquidised. This stream is fed to a flash tank in order to separate the gas-phase hydrogen, which contains slight amount of acetone. The distillation column distinguishes the acetone from unreacted IPA. The distillate stream has an acetone purity over 99%. The bottoms stream, which consists of residual IPA and slight amount of acetone, is recycled back into the mixer. The purpose of this study is to improve the simulation of isopropyl alcohol (IPA) dehydrogenation process by using the ChemCad program in terms of industrial applications.