Ethylene liquid phase reaction

Benzene alkylation (Union Carbide/ Badger) Ethylbenzene 2-4 125-140 AICI3 Benzene/ ethylene Liquid-phase reaction corrosive medium... 

CH2C1 CH2C1. Colourless liquid with an odour like that of chloroform b.p. 84 C. It is an excellent solvent for fats and waxes. Was first known as oil of Dutch chemists . Manufactured by the vapour- or liquid-phase reaction of ethene and chlorine in the presence of a catalyst. It reacts with anhydrous ethano-ales to give ethylene glycol diethanoate and with ammonia to give elhylenediamine, these reactions being employed for the manufacture of these chemicals. It burns only with difficulty and is not decomposed by boiling water. 

The liquid phase reaction of ethylene with carbon monoxide and oxygen over a Pd VCu " catalyst system produces acrylic acid. The yield based on ethylene is about 85%. Reaction conditions are approximately 140°C and 75 atmospheres ... 

Homogeneous gas phase reactors will always be operated continuously whereas liquid phase reactors may be batch or continuous. Tubular (pipe-line) reactors are normally used for homogeneous gas-phase reactions for example, in the thermal cracking of petroleum crude oil fractions to ethylene, and the thermal decomposition of dichloroethane to vinyl chloride. Both tubular and stirred tank reactors are used for homogeneous liquid-phase reactions. 

Note that ethylbenzene is a derivative of two basic organic chemicals, ethylene and benzene. A vapor-phase method with boron trifluoride, phosphoric acid, or alumina-silica as catalysts has given away to a liquid-phase reaction with aluminum chloride at 90°C and atmospheric pressure. A new Mobil-Badger zeolite catalyst at 420°C and 175-300 psi in the gas phase may be the method of choice for future plants to avoid corrosion problems. The mechanism of the reaction involves complexation of the... 

Polyethylene. The most straightforward process for the production of polymers from ethylene is that of the direct polymerization of the olefin. The polymerization process usually requires pressures and temperatures of 15,000 to 30,000 pounds per square inch and 200° to 300° C., and may be effected in either gas or liquid phase reactions (9). The polymer of molecular weight above 20,000 is the white, translucent plastic, polyethylene, widely used in electrical insulation, packaging material for foods, cosmetics and pharmaceuticals, liners for paper bags, etc. Articles molded from polyethylene are semirigid or rigid, depending on their thickness, but in thin films the material has excellent flexibility, even at relatively low temperatures. 

Alkylation. Friedel-Crafts alkylation (qv) of benzene with ethylene or propylene to produce ethylbenzene [100-41 -4], CgH10, or isopropylbenzene [98-82-8], C9H12 (cumene) is readily accomplished in the liquid or vapor phase with various catalysts such as BF3 (22), aluminum chloride, or supported polyphosphoric acid. The oldest method of alkylation employs the liquid-phase reaction of benzene with anhydrous aluminum chloride and ethylene (23). Ethylbenzene is produced commercially almost entirely for styrene manufacture. Cumene [98-82-8] is catalytically oxidized to cumene hydroperoxide, which is used to manufacture phenol and acetone. Benzene is also alkylated with C1Q—C20 linear alkenes to produce linear alkyl aromatics. Sulfonation of these compounds produces linear alkane sulfonates (LAS) which are used as biodegradable deteigents. 

This section is concerned with the activation of hydrocarbon molecules by coordination to noble metals, particularly palladium.504-513 An important landmark in the development of homogeneous oxidative catalysis by noble metal complexes was the discovery in 1959 of the Wacker process for the conversion of ethylene to acetaldehyde (see below). The success of the Wacker process provided a great stimulus for further studies of the reactions of noble metal complexes, which were found to be extremely versatile in their ability to catalyze homogeneous liquid phase reaction. The following reactions of olefins, for example, are catalyzed by noble metals hydrogenation, hydroformylation, oligomerization and polymerization, hydration, and oxidation. 

Styrene. Styrene is the largest benzene derivative with annual consumption about 11.5 billion lb in the United States. It is produced mainly by catalytic dehydrogenation of high-purity ethylbenzene (EB) in the vapor phase. The manufacture process for EB is based on ethylene alkylation with excess benzene. This can be done in a homogeneous system with aluminum chloride catalyst or a heterogeneous solid acid catalyst in either gas or liquid-phase reaction. In the past decade, the liquid-phase alkylation with zeolite catalyst has won acceptance. Those processes have advantages of easier product separation, reducing waste stream, and less corrosion. In addition, it produces less xylene due to lower... 

HPAs, however, is their solubility in polar solvents or reactants, such as water or ethanol, which severely limits their application as recyclable solid acid catalysts in the liquid phase. Nonetheless, they exhibit high thermal stability and have been applied in a variety of vapor phase processes for the production of petrochemicals, e.g. olefin hydration and reaction of acetic acid with ethylene [100, 101]. In order to overcome the problem of solubility in polar media, HPAs have been immobilized by occlusion in a silica matrix using the sol-gel technique [101]. For example, silica-occluded H3PW1204o was used as an insoluble solid acid catalyst in several liquid phase reactions such as ester hydrolysis, esterification, hydration and Friedel-Crafts alkylations [101]. HPAs have also been widely applied as catalysts in organic synthesis [102]. 

Description The liquid phase reaction of ethylene and chlorine releases approximately 220 kJ/mol of produced EDC. 

In most industrially relevant reacting systems, one main reaction typically makes the desired products and several side reactions make byproducts. The specific rate of production or consumption of a particular component in such a reaction set depends upon the stoichiometry and the rates. For example, assume that the main reaction for making vinyl acetate, Eq. (4.4.1, proceeds with a rate r< (mol/L s) and that the side reaction, Eq. (4.8), proceeds with rate r2 (mol/L s). Then the net consumption of ethylene is (-l)r1 - (-1 )r2 (mol/L s). Similarly, the net consumption of oxygen is (-0.5)fi + (— 3)r2, and the net production of water is (l)r-, + (2)ra. For a given chemistry (stoichiometry), our ability to control the production or consumption of any one component in the reactor is thus limited to how well we can influence the various rates. This boils down to manipulating the reactor temperature and/ or the concentrations of the dominant components. Occasionally, the reaction volume for liquid-phase reactions or the pressure for gas-phase reactions can also be manipulated for overall production control. These are the fundamentals of reactor control. 

The oldest method of alkylation with ethylene is the liquid phase reaction using anhydrous aluminum chloride as the catalyst. This reaction is a form of the classic Friedel-Crafts reaction and was discovered in 1879 by Balsohn. Most Lewis and Bronsted acids are known to be active for olefin alkylations. Alkylation by H2SO1, and H3PO1, was first shown by Ipatieff, et al, in 1936 who extended the reaction to isoparaffins. For the liquid phase alkylation of benzene with ethylene, however, aluminum chloride is preferred over the other acids, although a co-catalyst or promoter is usually needed to obtain efficient alkylation. AICI3 when dissolved in benzene containing some HCl forms a complex which can be simply described as ... 

The rapid initial absorption and reaction of ethylene forms polyethylbenzenes unselectively, and the slow liquid phase reaction of the polyethylbenzenes with unreacted benzene results in an approach towards thermodynamic equilibrium. That is, although the amounts of higher polyethylbenzene is negligible under thermodynamic control, they can be considerably under kinetic control. 

Ercan et al. studied the alkylation of ethylbenzene, EB, with light olefins (ethylene and propylene) over a commercial zeolite Y catalyst in a fixed-bed reactor with recycle [C. Ercan, F. M. Dautzenberg, C. Y. Yeh, and H. E. Earner, Ind. Eng. Chem. Res., 37 (1998) 1724]. The solid-catalyzed liquid-phase reaction was carried out in excess ethylbenzene at 25 bar and 190°C. Assume... 

In the thermolysis of trans-a-ethylene-a -acetylenoxirane, four electronic con-rotatory openings occur and three products are formed via an intermediate ylide. The cis isomer also yields similar products (Eq. 392). In the gas- and liquid-phase reactions of substituted derivatives it has been verified that the initial product in these thermolyses is the oxacycloheptatriene. ... 

Derivation (1) Ethylene is polymerized in a free-radical-initiated liquid-phase reaction at 1500 atm (22,000 psi) and 375F with oxygen as catalyst (usually from peroxides). (2) A much more effective and cheaper process uses pressures of only 100-300 psi at less than 212F the catalyst is undisclosed and reaction is vapor phase. 

Reaction pressure is sufficiently high so as to prevent any components from vaporizing in the alkylation reactor section. Alkylation reactors are typically operated at about 35-40 bar to maintain the reactor catalyst outlet streams in the liquid phase even at the maximum operating temperature. The ethylene injected into the reactor dissolves into the liquid hydrocarbon mixture such that the alkylation catalyst beds are always in the liquid phase. Reaction pressure is not normally varied during operation. 

Tubular and columnar apparatus (apparatus length-to-diameter ratio L/d > 100) including screw equipment relate to plug-flow reactors type [7,8]. Plug-flow reactors are applied for many of gas-phase reactions realized in production quantities, in particular for ethylene polymerization under high pressure conditions [9], and for some liquid-phase reactions, for example polystyrene synthesis in columns and other rubbers and plastics productions. Near 10% of polymer and 30% of fibers manufacture are produced in apparatus of such types [10]. 

The reaction can be carried out in a liquid or in a vapor phase. A liquid-phase reaction requires a 75-80 °C temperature and a mercuric sulfate catalyst. The acetylene gas is bubbled through glacial acetic acid and acetic anhydride. Vapor-phase reactions are carried out at 210-250 °C. Typical catalysts are cadmium acetate or zinc acetate. There are other routes to vinyl acetate as well, based on ethylene. 

Characteristic examples of industrial fast chemical reactions are the electrophilic polymerisation of isobutylene [7], its copolymerisation with isoprene [10], chlorination of olefins [17] and butyl rubber [18], ethylene hydrochlorination [17], sulfation of olefins [19], neutralisation of acidic and basic media [20], isobutene alkylation (production of benzines) [21-23], and so on. These examples of fast liquid-phase reactions and a variety of such processes assume a formal approach for their calculation and modelling, based on material and heat balance in the industrial implementation of respective products. It is a priori acknowledged that is not difficult to achieve an isothermic mode for fast chemical exothermic processes if you are aware of the process behaviour and can control it. 

The modern commercial process for making vinyl acetate is based on palladium-catalyzed oxidative coupling of ethylene and acetic acid [217]. This process has largely supplanted the older acetylene based method of preparing vinyl acetate. Again, this reaction can be carried out by either a liquid- or a gas-phase process. The basic chemistry of the liquid-phase reaction is shown in the following equations (34) 36). 

The use of a laboratory batch reactor to determine the specific reaction rate constant, k, for the liquid-phase reaction EO form ethylene glycol. 

Ethjlben ne Synthesis. The synthesis of ethylbenzene for styrene production is another process in which ZSM-5 catalysts are employed. Although some ethylbenzene is obtained direcdy from petroleum, about 90% is synthetic. In earlier processes, benzene was alkylated with high purity ethylene in liquid-phase slurry reactors with promoted AlCl catalysts or the vapor-phase reaction of benzene with a dilute ethylene-containing feedstock with a BF catalyst supported on alumina. Both of these catalysts are corrosive and their handling presents problems. 

The major method for preparing the monomer commercially since the early 1960s has been the so-called balanced process from ethylene. In the first stage of the reaction, 1,2-dichloroethane is prepared by reacting ethylene with chlorine in either the vapour or the liquid phase Figure 12.2). In a typical liquid phase... 

The effect of physical processes on reactor performance is more complex than for two-phase systems because both gas-liquid and liquid-solid interphase transport effects may be coupled with the intrinsic rate. The most common types of three-phase reactors are the slurry and trickle-bed reactors. These have found wide applications in the petroleum industry. A slurry reactor is a multi-phase flow reactor in which the reactant gas is bubbled through a solution containing solid catalyst particles. The reactor may operate continuously as a steady flow system with respect to both gas and liquid phases. Alternatively, a fixed charge of liquid is initially added to the stirred vessel, and the gas is continuously added such that the reactor is batch with respect to the liquid phase. This method is used in some hydrogenation reactions such as hydrogenation of oils in a slurry of nickel catalyst particles. Figure 4-15 shows a slurry-type reactor used for polymerization of ethylene in a sluiTy of solid catalyst particles in a solvent of cyclohexane. 

The sulfation reaction occurs in the liquid phase at approximately 35 °C. An 85 wt% alcohol yield could be realized. The reaction is similar to the sulfation of ethylene or propylene and results in a mixture of sec-butyl hydrogen sulfate and di-sec-butyl sulfate. The mixture is further hydrolyzed to sec-butanol and sulfuric acid ... 

The ozonolysis of ethylene in the liquid phase (without a solvent) was shown to take place by the Criegee mechanism.This reaction has been used to study the structure of the intermediate 16 or 17. The compound dioxirane (21) was identified in the reaetion mixture at low temperatures and is probably in equilibrium with the biradical 17 (R = H). Dioxirane has been produced in solution but it oxidatively cleaves dialky] ethers (such as Et—O—Et) via a chain radical process, so the choice of solvent is important. 

We have developed a compact photocatalytic reactor [1], which enables efficient decomposition of organic carbons in a gas or a liquid phase, incorporating a flexible and light-dispersive wire-net coated with titanium dioxide. Ethylene was selected as a model compound which would rot plants in sealed space when emitted. Effects of the titanium dioxide loading, the ethylene concentration, and the humidity were examined in batches. Kinetic analysis elucidated that the surface reaction of adsorbed ethylene could be regarded as a controlling step under the experimental conditions studied, assuming the competitive adsorption of ethylene and water molecules on the same active site. 

Finally, it is appropriate to close this chapter with an example from the roots of fine chemicals the dyestuff, indigo. Manufacture of indigo involves chemistry (see Fig. 2.15) which has hardly changed from the time of the first commercial synthesis more than a hundred years ago (see earlier). Mitsui Toatsu has developed a two-step process in which indole is produced by vapour-phase reaction of ethylene glycol with aniline over a supported silver catalyst (Inoue et al., 1994). Subsequent liquid-phase oxidation of the indole, with an alkyl hydroperoxide in the presence of a soluble molybdenum catalyst, affords indigo. 

Ethyl acetate is an oxygenated solvent widely used in the inks, pharmaceuticals and fragrance sectors. The current global capacity for ethyl acetate is 1.2 million tonnes per annum. BP Chemicals is the world s largest producer of ethyl acetate. Conventional methods for the production of ethyl acetate are either via the liquid phase esterification of acetic acid and ethanol or by the coupling of acetaldehyde also known as the Tischenko reaction. Both of these processes require environmentally unfriendly catalysts (e.g. p-toluenesulphonic acid for the esterification and metal chlorides and strong bases for the Tischenko route). In 1997 BP Chemicals disclosed a new route to produce ethyl acetate directly from the reaction of ethylene with acetic acid using supported heteropoly acids... 

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