Material cumene synthesis

By far the preponderance of the 3400 kt of current worldwide phenolic resin production is in the form of phenol-formaldehyde (PF) reaction products. Phenol and formaldehyde are currently two of the most available monomers on earth. About 6000 kt of phenol and 10,000 kt of formaldehyde (100% basis) were produced in 1998 [55,56]. The organic raw materials for synthesis of phenol and formaldehyde are cumene (derived from benzene and propylene) and methanol, respectively. These materials are, in turn, obtained from petroleum and natural gas at relatively low cost ([57], pp. 10-26 [58], pp. 1-30). Cost is one of the most important advantages of phenolics in most applications. It is critical to the acceptance of phenolics for wood panel manufacture. With the exception of urea-formaldehyde resins, PF resins are the lowest cost thermosetting resins available. In addition to its synthesis from low cost monomers, phenolic resin costs are often further reduced by extension with fillers such as clays, chalk, rags, wood flours, nutshell flours, grain flours, starches, lignins, tannins, and various other low eost materials. Often these fillers and extenders improve the performance of the phenolic for a particular use while reducing cost. 

Treybal, in his book Liquid Extraction [1], works equilibrium material balances with triangular coordinates. The most unique and simple way to show three-phase equilibrium is a triangular diagram (Fig. 7.1), which is used for extraction unit operation in cumene synthesis plants [2], In this process benzene liquid is used as the solvent to extract acetic acid (the solute) from the liquid water phase (the feed-raffinate). The curve D,S,P,F,M is the equilibrium curve. Note that every point inside the triangle has some amount of each of the three components. Points A,... 

PROPENE The major use of propene is in the produc tion of polypropylene Two other propene derived organic chemicals acrylonitrile and propylene oxide are also starting materials for polymer synthesis Acrylonitrile is used to make acrylic fibers (see Table 6 5) and propylene oxide is one component in the preparation of polyurethane polymers Cumene itself has no direct uses but rather serves as the starting material in a process that yields two valuable indus trial chemicals acetone and phenol... 

The most widely used industrial synthesis of phenol is based on isopropylbenzene (cumene) as the starting material and is shown m the third entry of Table 24 3 The eco nomically attractive features of this process are its use of cheap reagents (oxygen and sulfuric acid) and the fact that it yields two high volume industrial chemicals phenol and acetone The mechanism of this novel synthesis forms the basis of Problem 24 29 at the end of this chapter... 

Phenol is the starting material for numerous intermediates and finished products. About 90% of the worldwide production of phenol is by Hock process (cumene oxidation process) and the rest by toluene oxidation process. Both the commercial processes for phenol production are multi step processes and thereby inherently unclean [1]. Therefore, there is need for a cleaner production method for phenol, which is economically and environmentally viable. There is great interest amongst researchers to develop a new method for the synthesis of phenol in a one step process [2]. Activated carbon materials, which have large surface areas, have been used as adsorbents, catalysts and catalyst supports [3,4], Activated carbons also have favorable hydrophobicity/ hydrophilicity, which make them suitable for the benzene hydroxylation. Transition metals have been widely used as catalytically active materials for the oxidation/hydroxylation of various aromatic compounds. 

Propene is used as a starting material for the synthesis of acetone, cumene (isopropylbenzene), and polypropylene (PP). 

The method with cumene hydroperoxide has been recently used with success,to prepare both enantiomers of methyl p-methoxyphenyl sulfoxide which were then taken as starting material for the total synthesis of biological compounds. 

The purpose of the present work is to incorporate aluminum into the framework of SBA-15 during the synthesis in order to create acid sites on the surface of the material directly and to enhance its activity in acid-catalyzed reactions and to study the stability of SBA and AlSBA molecular sieves under various treatments. The influence of these treatments on the pore size, wall thickness and the environment of Al in these materials are investigated in detail. X-ray diffraction (XRD), Electron Microscopy (TEM) and N2 adsorption were used to characterize the structure, the porosity and the stability of these materials. 27Al MAS NMR was used to ascertain the nature and environment of Al, cumene cracking to test the catalytic activity of parent materials and ammonia chemisorption to probe their surface acidity. 

Acetone is also produced (in greater volnme) as the coproduct with phenol of the oxidation of cumene (see earlier). It is a widely used solvent and is the starting material for the synthesis of a number of polymers. 

The catalytic work on the zeolites has been carried out using the pulse microreactor technique (4) on the following reactions cracking of cumene, isomerization of 1-butene to 2-butene, polymerization of ethylene, equilibration of hydrogen-deuterium gas, and the ortho-para hydrogen conversion. These reactions were studied as a function of replacement of sodium by ammonium ion and subsequent heat treatment of the material (3). Furthermore, in some cases a surface titration of the catalytic sites was used to determine not only the number of sites but also the activity per site. Measurements at different temperatures permitted the determination of the absolute rate at each temperature with subsequent calculation of the activation energy and the entropy factor. For cumene cracking, the number of active sites was found to be equal to the number of sodium ions replaced in the catalyst synthesis by ammonium ions up to about 50% replacement. This proved that the active sites were either Bronsted or Lewis acid sites or both. Physical defects such as strains in the crystals were thus eliminated and the... 

Cumene is prepared on a large scale from benzene and propylene as an intermediate in the synthesis of acetone and phenol. This makes it an inexpensive and readily available starting material for the production of Galaxolide . Three further electrophilic addition reactions complete the synthesis. Firstly, isoamylene is added, to form pentamethylindane, to which propylene oxide is added. Finally, treatment with formaldehyde leads, via the hemiacetal, to the isochroman. 

The most important example of stoichiometric asymmetric oxidation is probably the titanium-catalysed conversion of sulfides into sulfoxides by cumene hydroperoxide in the presence of stoichiometric diethyl tartrate. A simple example is the efficient asymmetric synthesis of methyl p-tolyl sulfoxide 162, an important starting material for much sulfoxide-controlled asymmetric synthesis.30... 

By far the most important use of benzene is as a raw material in the synthesis of other organic compounds. More than 90 percent of the benzene produced in the United States is used to make ethylbenzene (55 percent), cumene (34 percent), and cyclohexane (12 percent). The first two compounds rank fifteenth and twentieth, respectively, among all chemicals produced in the United States each year. Another five percent of benzene production goes to the synthesis of a large variety of other organic compounds, including nitrobenzene, chlorobenzene, and maleic anhydride, a raw material for the manufacture of plastics. Smaller amounts of benzene are used as a solvent for... 

About 15.3 million metric tons (16.8 million short tons) of propylene were produced for commercial sale in the United States in 2004. About 39 percent of that amount was used for the production of polypropylene. Almost all of the remaining production was also used for the synthesis of chemical compounds, especially acrylonitrile (14 percent), propylene oxide (11 percent), cumene (10 percent), oxo alcohols (8 percent), isopropyl alcohol (7 percent), oligomers (5 percent) and acrylic acid (3 percent). Acrylonitrile, propylene oxide, oxo alcohols, and acrylic acids are all used primarily for the production of various types of polymers. Cumene is itself used as a raw material in the production of other organic compounds, especially acetone and phenol. 

Suppose that the reactant A is totally consumed. If the reaction rate is not infinite, the reactant B must be recycled at a convenient rate, in such a way that the resulting reaction rate leads to the total consumption of A. Therefore, we may speak about total conversion of the one-pass reactant, and partial conversion of the recycled reactant. Because the feed of fresh reactants must respect the stoichiometry, the feed policy of B must be adapted to fulfil the dynamic material balance. The above situation can be found often in industry, as for instance the synthesis of ethers from alchene-oxides and alcohols, the alkylation of benzene with ethylene or propylene to ethylbenzene or cumene, the addition of HCN to ketones, etc. 

Note that the benzenonium ion contains resonance structures putting the positive charge on carbons ortho and para to the incoming electrophile. This intermediate will lose a proton to form the desired product, cumene. Cumene, itself, is the starting material in an useful synthesis of phenol. This process involves the air oxidation of... 

A method is described for the preparation of zinc-containing zeolite by direct synthesis from hydrogels. The synthesis of Zn-MFI type zeolite materials and the post synthesis introduction of Cu are discussed. The samples are characterized by XRD, AAS, thermal analysis, SEM and Si-NMR spectroscopy. The catalytic results on the cumene conversion are discussed. 

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