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Phase process

Almost all aspects of the field of chemistry involve tire flow of energy eitlier witliin or between molecules. Indeed, tire occurrence of a chemical reaction between two species implies tire availability of some minimum amount of energy in tire reacting system. The study of energy transfer processes is tluis a topic of fundamental importance in chemistry. Energy transfer in gases is of particular interest partly because very sophisticated methods have been developed to study such events and partly because gas phase processes lend tliemselves to very complete and detailed tlieoretical analysis. [Pg.2996]

Alkylthiazoles can be oxidized to nitriles in the presence of ammonia and a catalyst. For example, 4-cyanothiazole was prepared from 4-methylthiazole by a one-step vapor-phase process (94) involving reaction with a mixture of air, oxygen, and ammonia at 380 to 460°C. The catalyst was M0O3 and V Oj or M0O3, VjOj, and CoO on an alumina support. [Pg.531]

Whereas recombinant proteins produced as inclusion bodies in bacterial fermentations may be amenable to reversed-phase chromatography (42), the use of reversed-phase process chromatography does not appear to be widespread for higher molecular weight proteins. [Pg.55]

The reaction of adipic acid with ammonia in either Hquid or vapor phase produces adipamide as an intermediate which is subsequentiy dehydrated to adiponitrile. The most widely used catalysts are based on phosphoms-containing compounds, but boron compounds and siHca gel also have been patented for this use (52—56). Vapor-phase processes involve the use of fixed catalyst beds whereas, in Hquid—gas processes, the catalyst is added to the feed. The reaction temperature of the Hquid-phase processes is ca 300°C and most vapor-phase processes mn at 350—400°C. Both operate at atmospheric pressure. Yields of adipic acid to adiponitrile are as high as 95% (57). [Pg.220]

In 1987, Toray Industries, Inc., announced the development of a new process for making aromatic nitriles which reportedly halved the production cost, reduced waste treatment requirements, and reduced production time by more than two-thirds, compared with the vapor-phase process used by most producers. The process iavolves the reaction of ben2oic acid (or substituted ben2oic acid) with urea at 220—240°C ia the presence of a metallic catalyst (78). [Pg.225]

This was a Hquid-phase process which used what was described as siUceous zeoUtic catalysts. Hydrogen was not required in the process. Reactor pressure was 4.5 MPa and WHSV of 0.68 kg oil/h kg catalyst. The initial reactor temperature was 127°C and was raised as the catalyst deactivated to maintain toluene conversion. The catalyst was regenerated after the temperature reached about 315°C. Regeneration consisted of conventional controlled burning of the coke deposit. The catalyst life was reported to be at least 1.5 yr. [Pg.416]

Liquid- and vapor-phase processes have been described the latter appear to be advantageous. Supported cadmium, zinc, or mercury salts are used as catalysts. In 1963 it was estimated that 85% of U.S. vinyl acetate capacity was based on acetylene, but it has been completely replaced since about 1982 by newer technology using oxidative addition of acetic acid to ethylene (2) (see Vinyl polymers). In western Europe production of vinyl acetate from acetylene stiU remains a significant commercial route. [Pg.102]

Adsorption. In the design of the adsorption step of gas-phase processes, two phenomena must be considered, equiUbrium and mass transfer. Sometimes adsorption equiUbrium can be regarded as that of a single component, but mote often several components and their interactions must be accounted for. Design techniques for each phenomenon exist as well as some combined models for dynamic performance. [Pg.285]

Bromine Trifluoride. Bromine trifluoride is produced commercially by the reaction of fluorine with bromine ia a continuous gas-phase process where the ratio of fluorine to bromine is maintained close to 3 1. It is also produced ia a Hquid-phase batch reaction where fluorine is added to Hquid bromine at a temperature below the boiling poiat of bromine trifluoride. [Pg.186]

Heterogeneous vapor-phase fluorination of a chlorocarbon or chlorohydrocarbon with HP over a supported metal catalyst is an alternative to the hquid phase process. Salts of chromium, nickel, cobalt or iron on an A1P. support are considered viable catalysts in pellet or fluidized powder form. This process can be used to manufacture CPC-11 and CPC-12, but is hampered by the formation of over-fluorinated by-products with Httle to no commercial value. The most effective appHcation for vapor-phase fluorination is where all the halogens are to be replaced by fluorine, as in manufacture of 3,3,3-trifluoropropene [677-21 ] (14) for use in polyfluorosiHcones. [Pg.268]

Trioxane and Tetraoxane. The cycHc symmetrical trimer of formaldehyde, trioxane [110-88-3] is prepared by acid-catalyzed Hquid- or vapor-phase processes (147—151). It is a colorless crystalline soHd that bods at 114.5°C and melts at 61—62°C (17,152). The heats of formation are — 176.9 kJ/mol (—42.28 kcal/mol) from monomeric formaldehyde and —88.7 kJ/mol (—21.19 kcal/mol) from 60% aqueous formaldehyde. It can be produced by continuous distillation of 60% aqueous formaldehyde containing 2—5% sulfuric acid. Trioxane is extracted from the distillate with benzene or methylene chloride and recovered by distillation (153) or crystallization (154). It is mainly used for the production of acetal resins (qv). [Pg.498]

Vinyl ethers are prepared in a solution process at 150—200°C with alkaH metal hydroxide catalysts (32—34), although a vapor-phase process has been reported (35). A wide variety of vinyl ethers are produced commercially. Vinyl acetate has been manufactured from acetic acid and acetylene in a vapor-phase process using zinc acetate catalyst (36,37), but ethylene is the currently preferred raw material. Vinyl derivatives of amines, amides, and mercaptans can be made similarly. A/-Vinyl-2-pyrroHdinone is a commercially important monomer prepared by vinylation of 2-pyrroHdinone using a base catalyst. [Pg.374]

Finally, selective hydrogenation of the olefinic bond in mesityl oxide is conducted over a fixed-bed catalyst in either the Hquid or vapor phase. In the hquid phase the reaction takes place at 150°C and 0.69 MPa, in the vapor phase the reaction can be conducted at atmospheric pressure and temperatures of 150—170°C. The reaction is highly exothermic and yields 8.37 kJ/mol (65). To prevent temperature mnaways and obtain high selectivity, the conversion per pass is limited in the Hquid phase, and in the vapor phase inert gases often are used to dilute the reactants. The catalysts employed in both vapor- and Hquid-phase processes include nickel (66—76), palladium (77—79), copper (80,81), and rhodium hydride complexes (82). Complete conversion of mesityl oxide can be obtained at selectivities of 95—98%. [Pg.491]

The hquid-phase processes are more energy efficient than the vapor-phase processes, however, they iacur costiy high pressure equipment investment and also produce waste streams containing used catalyst (213). Both methods produce substantial quantities of by-products which cause refining difficulties. The by-products consist primarily of mesitylene [108-67-8] phorone [504-20-17, and the foUowiag xyUtone isomers (215) ... [Pg.495]

Substantial amounts of 3,3,6,8-tetramethyl-l-tetralone [5409-55-2] are also formed, most notably ia the vapor-phase process (216). This tetralone has been synthesized from isophorone and mesityl oxide and it can thus be assumed to be a product of these two materials ia the isophorone process (217,218). [Pg.495]

Depending on the means of conversion of manganate(V) to (VI), the process may be classified as a roasting or Hquid-phase process (Fig. 8). The roasting process employs a soHd reaction mixture having a molar ratio between MnO and KOH in the range of 1 2 to 1 3. In contrast, the Hquid-phase route operates at a higher (>1 5) molar ratio between MnO and KOH. [Pg.517]

The roasting process, or variations of it, are most common. Liquid-phase processes are ia operation, however, both ia the United States and the former USSR. The former USSR is the only place where KMnO was produced by anodic oxidation of ferromanganese. Table 17 summarizes the various KMnO manufactuting faciUties worldwide as of this writing. [Pg.518]

Olefin Separation. Olefin-containing streams are separated either by the OlefinSiv process (Union Carbide Corp.) separating / -butenes from isobutenes in the vapor phase, or the Olex process (Universal Oil Product) a Hquid-phase process. [Pg.457]

Both vapor-phase and Hquid-phase processes are employed to nitrate paraffins, using either HNO or NO2. The nitrations occur by means of free-radical steps, and sufftciendy high temperatures are required to produce free radicals to initiate the reaction steps. For Hquid-phase nitrations, temperatures of about 150—200°C are usually required, whereas gas-phase nitrations fall in the 200—440°C range. Sufficient pressures are needed for the Hquid-phase processes to maintain the reactants and products as Hquids. Residence times of several minutes are commonly required to obtain acceptable conversions. Gas-phase nitrations occur at atmospheric pressure, but pressures of 0.8—1.2 MPa (8—12 atm) are frequentiy employed in industrial units. The higher pressures expedite the condensation and recovery of the nitroparaffin products when cooling water is employed to cool the product gas stream leaving the reactor (see Nitroparaffins). [Pg.35]

Eor vapor-phase processes, the product stream from the nitrator must be separated. The nitroparaffins, excess propane, and NO plus NO2 (which are converted back to HNO ), are recovered. The oxygenated products are removed, but there are generally insufficient amounts for economic recovery. [Pg.36]

The vapor-phase process of SocifitH Chemique de la Grande Paroisse for production of nitroparaffins employs propane, nitrogen dioxide, and air as feedstocks (34). The yields of nitroparaffins based on both propane and nitrogen dioxide are relatively high. Nitric oxide produced during nitration is oxidized to nitrogen dioxide, which is adsorbed in nitric acid. Next, the nitric dioxide is stripped from the acid and recirculated. [Pg.36]

Nitromethane, nitroethane, 1-nitropropane, and 2-nitropropane are produced by a vapor-phase process developed ia the 1930s (2). [Pg.97]

Eig. 1. Melting curves (dsc) of two ethylene—1-hexene copolymers produced in a gas-phase process one with a uniform branching distribution (1-hexene content 2.5 mol %) and another with a nonuniform branching distribution (1-hexene content 2.8 mol %). [Pg.395]

Eluidized-bed reactors are highly versatile and can accommodate many types of polymerization catalysts. Most of the catalysts used for LLDPE production are heterogeneous Ziegler catalysts, in both supported and unsupported forms. The gas-phase process can also accommodate supported metallocene catalysts that produce compositionaHy uniform LLDPE resins (49—51). [Pg.399]

In the Godrej-Lurgi process, olefins are produced by dehydration of fatty alcohols on alumina in a continuous vapor-phase process. The reaction is carried out in a specially designed isothermal multitube reactor at a temperature of approximately 300°C and a pressure of 5—10 kPa (0.05—0.10 atm). As the reaction is endothermic, temperature is maintained by circulating externally heated molten salt solution around the reactor tubes. The reaction is sensitive to temperature fluctuations and gradients, hence the need to maintain an isothermal reaction regime. [Pg.440]

In addition to the Hquid-phase -butyl nitrite (BN) process, UBE Industries has estabHshed an industrial gas-phase process using methyl nitrite (50—52). The oudine of the process is described in Eigure 4 (52). This gas-phase process is operated under lower reaction pressure (at atmospheric pressure up to 490 kPa = 71 psi) and is more economical than the Hquid-phase process because of the foUowing reasons owing to the low pressure operation, the consumption of electricity is largely reduced (—60%) dimethyl oxalate (DMO) formation and the methyl nitrite (MN) regeneration reaction are mn... [Pg.459]


See other pages where Phase process is mentioned: [Pg.799]    [Pg.234]    [Pg.37]    [Pg.51]    [Pg.72]    [Pg.851]    [Pg.1038]    [Pg.55]    [Pg.416]    [Pg.164]    [Pg.285]    [Pg.25]    [Pg.313]    [Pg.476]    [Pg.36]    [Pg.384]    [Pg.384]    [Pg.385]    [Pg.388]    [Pg.399]    [Pg.399]    [Pg.402]    [Pg.404]    [Pg.430]    [Pg.459]   
See also in sourсe #XX -- [ Pg.604 ]




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Absorption, phase transfer processes

Acetic anhydride Liquid phase process

Acetic anhydride Vapor phase process

Adsorption equipment liquid phase process

Adsorption-desorption process liquid phase applications

Adsorption-desorption process vapor phase applications

Advanced liquid phase processes

Advanced vapor phase processes

Ammonia injection process, vapor-phase

Aqueous phase process

Aqueous phase processing

Aqueous phase reforming process

Aqueous-phase chemistry chemical removal processes

BRs FOR TWO- AND THREE-PHASE PROCESSES

Bimolecular process liquid-phase reactions

Bonded stationary phases condensation process

Butane isomerization liquid-phase processes

Butane isomerization vapor phase processes

By Andrew Gilbert Physical Aspects of Photochemistry Photophysical Processes in Condensed Phases

Cascade Processes Initiated by Conjugate Addition via Phase-transfer Catalysis

Catalyst Characterization for Gas Phase Processes

Chemical processes life cycle phases

Chemical processing plants, life cycles phases

Chromatographic processes stationary phases

Coagulation process, phase transition

Condensed phase processes

Continuous fibers vapor phase processes

Coupling with solid-phase process

Cracking processes vapor-phase

Criterion of First Phase Choice at Reaction-Diffusion Processes

Crystalline phases process

Cycle Phases and the System Safety Process

Cyclohexane liquid phase process

Data processing phase correction

Design process maintenance phases

Desorption, phase transfer processes

Distillation phase transfer processes

Drug approvals, process phases

Drug development process clinical phase

Drug development process toxicological phase

Dry phase Inversion process

Drying process phases

Effects of Processing Parameters on Phase Morphology

Enantioselective phase transfer alkylation process

Endothermic processes phase changes

Energy Balances on Single-Phase Nonreactive Processes

Example of Process Simulation With Excel Including Phase Equilibrium

Exothermic processes phase changes

Exothermic processes phase transitions

Experimental evaluation, liquid phase processes

Extraction phase transfer processes

Extraction processes dispersed phase selection

Extraction processes phase equilibrium

Feed system, liquid phase processes

Film forming processing surface-oriented phase

Fischer-Tropsch process phase

Flash processes three phase

Flow diagram of the polypropylene horizontal reactor gas phase process

Flow diagram of the polypropylene vertical reactor gas phase process

Forming , solid-phase process

Fundamental processes in gas-phase radiation chemistry

Fundamentals of Fast Liquid-phase Chemical Processes

Gas phase process

Gas phase, oxidation processes

Gas-Phase Chemical Reduction Process for Site Remediation

Gas-Phase Plasma Decomposition Processes

Gas-Phase Process Company History

Gas-Phase Process Licensors

Gas-Phase-Mediated Processes Related to SSIE

Gas-phase olefin polymerization process

Glasses phase separation processes

Heat and Mass Exchange Intensification in Fast Liquid-phase Processes

Heterogeneous catalytic processes phases

Horizontal Gas-Phase Process

Hydrogenation processes liquid-phase

Induction Times and the Onset of Electrochemical Phase Formation Processes

Innovene gas-phase process

Investigational New Drugs Application Process Phase

Isomerization Shell Liquid-phase process

Isothermic processes phase transitions

Leading with Safety process phase

Life Cycle Phases and the System Safety Process

Liquid Phase Process Characterization

Liquid Phase Zinc Chloride Process

Liquid phase catalytic processing

Liquid phase methanol process

Liquid phase oxidation process

Liquid phase process

Liquid phase process, vinyl acetate

Mass transport processes mobile phase

Mass transport processes stationary phase

Membrane processes liquid-phase separations

Metallic phases, diffusion process

Methanol, production liquid phase process

Microfiltration phase-inversion process

Mineral processing three phase interactions

Mobile phase solvation processes

Molding processes single phase polymers

Monolithic reactors three-phase processes

Moving Nanoparticles Around Phase-Transfer Processes in Nanomaterials Synthesis

Multi-phase processes

Nanofiltration membranes phase-inversion process

Non-Equilibrium Discharge Conditions and Gas-Phase Plasma-Chemical Processes in the Systems Applied for Synthesis of Diamond Films

Operation Problems of Fast Liquid-phase Processes

Optimization Phase Development of an Economic Process

Oxidation Vapor phase processes

PART I PHYSICAL ASPECTS OF PHOTOCHEMISTRY Photophysical Processes in Condensed Phases

PRELIMINARY DATA PROCESSING AND PHASE ANALYSIS

Pervaporation, phase transfer processe

Phase Equilibrium Process

Phase Oxidation Processes for Hydrogen Sulfide Removal

Phase Transitions and Topochemical Processes

Phase boundary processes

Phase correction process

Phase cycling computer processing

Phase formation processes

Phase inversion polymer processing

Phase inversion process

Phase inversion processes, production

Phase processing operations

Phase separation process

Phase separation spin-coating process

Phase separation/inversion process

Phase splitting extraction processes

Phase transfer process

Phase transfer processes Subject

Phase-change/thermal process

Phase-conjugate processes

Phase-separation process thermosetting systems

Phased remedial investigation process

Phases of the Drying Process

Photolysis, condensed phase process

Photophysical Processes in Condensed Phases

Poly networks phase-separation process, morphologies

Polyethylene gas phase process

Polyethylene slurry phase/suspension process

Polyethylene solution phase process

Polymer-assisted phase Inversion process

Polymer-blend thin films phase-separation process

Polymeric membranes phase separation process

Polymerizations phase separation process

Preparation of Cellulose Hydrogel Film with Phase Inversion Process

Process Chain for Quantitative Evaluation of the Pre-crash Phase

Process changes three-phase implementation

Process chemistry clinical phase

Process control, liquid phase processes

Process design phase

Process design phase 1 review

Process design phase 1 specifications

Process development phase

Process development phase wastewater

Process qualification phase

Process synthesis phase change

Process units mixed phase flow

Processes three-phase

Processing phase correction

QM/MM methods for simulation of condensed phase processes

Reactions three phase batch processes

Reactions three phase continuous processes

Reactions vapor phase processes

Reactors for catalytic gas phase processes

Reactors liquid phase processes

Results of the Gas-Phase Polymerization Process Exergy Analysis

Reverse osmosis membranes phase-inversion process

Reversed-phase HPLC process

Reversed-phase chromatography elution process

Reversed-phase retention process models

Reversible process phase changes

Rules of Thumb about the Context for a Chemical Process Heterogenous Phase contacting

Second-order point process phase space

Shell liquid-phase process

Single phase processes

Slurry Phase Distillate process

Slurry phase processes

Slurry phase/suspension process

Software development process implementation phase

Solid Phase Deformation Processes

Solid Phase Pressure Forming Process

Solid phase advanced processes

Solid phase extraction process

Solid-Phase Processes

Solid-phase extrusion process

Solution phase process

Sterilization process phases

Storage and Process-induced Phase Transformations

Synthetic Applications of Phase-transfer Processes

System capabilities, liquid phase processe

System liquid phase processes

The Gas-phase Ethylene to Vinyl Acetate Process

The Liquid Phase Process

The Spontaneous Three-phase Cocoa Bean Fermentation Process

The Vapor Phase Process

Thermal phase-inversion process

Thermal phase-separation process

Thermodynamic phase-equilibrium mixing process

Thermodynamics Process Control in Fluid-phase Equilibria

Thin films phase-separation process

Thorex process third phase formation

Three-dimensional model phases process

Titanium phase-formation process

Two liquid phase processes

Two-phase organic processes

Two-phase process

Ultrafiltration membranes phase-inversion process

Ultrafiltration phase inversion process

Union Carbide gas-phase process

Vapor phase process, commercial

Vapor-phase ethylene hydration process

Vapor-phase ethylene process

Vapor-phase polymerization process

Vapor-phase process

Vapor-phase processing

Vapour phase transport processes

Wet phase inversion process

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