Cumene from Benzene and Propylene

Cumene (isopropylbenzene) is the major intermediate (10.6 Mt/a was the world capacity in 2004) for the manufacture of phenol. It is formed by alkylation of benzene with propylene according to Equation 6. Propylene is believed to react with hydrogen chloride forming the more stable secondary carbocation, which is associated with the tetrachloroaluminate anion. The ion pair reacts further with benzene to give the product. 

Commercial zeolites are usually mixed with a binder such as y-alumina and shaped into pellets. The shaping procedure causes changes in binder porosity to give zeolites with different physical properties. 

No industrial process can be considered as the ultimate, and research continuously provides new alternatives for economic assessment. 

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Q-Max A process for making cumene from benzene and propylene by catalytic alkylation using a proprietary legenerable zeolite catalyst. Developed by UOP and first installed in 1996 by JLM Chemicals in Illinois. 

Production of cumene from benzene and propylene using a phosphoric acid on quartz catalyst (Fig. 19-22c). There are four reactor beds with interbed cooling with cold feed. The reactor operates at 260°C. 

FIG. 19-22 Temperature and composition profiles, (a) Oxidation of S02 with intercooling and two cold shots, (b j Phosgene from CO and Cl2, activated carbon in 2-in tubes, water-cooled, (c) Cumene from benzene and propylene, phosphoric acid on quartz with four quench zones, 260°C. (d) Vertical ammonia synthesizer at 300 atm, with five cold shots and an internal exchanger, le) Vertical methanol synthesizer at 300 atm, Cr203-Zn0 catalyst, with six cold shots totaling 10 to 20 percent of the fresh feed. To convert psi to kPa, multiply by 6.895 atm to kPa, multiply by 101.3. 

The following alkylated benzenes are of major industrial importance ethylbenzene produced from benzene and ethylene cumene from benzene and propylene and dodecylbenzenes from benzene and linear C12 olefins. Both liquid catalysts and more recently solid catalysts are employed commercially. 

A shell-and-tube reactor, as illustrated in Figure 19.1. is used for the following reaction to produce cumene from benzene and propylene. 

An optimized preliminary design of a plant to make cumene from benzene and propylene using the new catalyst. 

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. 

Application To produce cumene from benzene and any grade of propylene—including lower-quality refinery propylene-propane mixtures—using the Badger process and a new generation of zeolite catalysts from ExxonMobil. 

Autoxidation is one of the key steps in the industrial synthesis of phenol and acetone from benzene and propylene. In the second step of this synthesis, cumene (isopropylbenzene) is autoxidized to give cumyl hydroperoxide. 

Derivation From benzene and propylene by use of aluminum chloride and hydrochloric acid to yield cumene, which is then dehydrogenated. 

Production of cymenes or isopropyl toluene from toluene and propylene is an adaptation of cumene process from benzene and propylene. Through hydroperoxidation of cumene and cleavage of the resultant molecule, phenol and acetone are produced. 

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 reactions for cumene production from benzene and propylene are as follows ... 

Cumene is derived from benzene and propylene as shown in Figure 10.64. 

Phenol is a petrochemical derived from benzene and propylene by the cumene route, and formaldehyde is obtained by the oxidation of methanol which in turn is derived from synthesis gas. Until the 1950s, phenol, as extracted from coal tar by distillation, was contaminated with cresols and xylenols. 

In more recent vintages of the cumene manufacture processes, zeolyte catalysts permit going directly to cumene from the same two feeds, benzene and propylene. The introduction of catalytic distillation has even further improved the process economics, a thing that delights the manufacturers. 

In a Texas two-step that has led to a more economical route for cumene, new catalysts combined with a novel processing scheme has reduced both operating costs and increased the yield of cumene from its benzene and propylene feedstocks. In Figure 7-3, the main reaction takes place in a catalytic distillation column. This piece of apparatus combines a catalyst-filled reactor with a fractionator. 

There are nine chemicals in the top 50 that are manufactured from benzene. These are listed in Table 11.1. Two of these, ethylbenzene and styrene, have already been discussed in Chapter 9, Sections 5 and 6, since they are also derivatives of ethylene. Three others—cumene, acetone, and bisphenol A— were covered in Chapter 10, Sections 3-5, when propylene derivatives were studied. Although the three carbons of acetone do not formally come from benzene, its primary manufacturing method is from cumene, which is made by reaction of benzene and propylene. These compounds need not be discussed further at this point. That leaves phenol, cyclohexane, adipic acid, and nitrobenzene. Figure 11.1 summarizes the synthesis of important chemicals made from benzene. Caprolactam is the monomer for nylon 6 and is included because of it importance. 

There are three basic ways a species may lose its chemical identity. One way is by decomposition, in which a molecule is broken down into smaller molecules, atoms, or atom fragments. For example, if benzene and propylene are formed from a cumene molecule. 

P10-23b Benzene and propylene are produced from the eraeking of eumene over a sil-iea-alumina eatalyst. Unfortunately, a trace amount, of eumene hydroperoxide ean deaetivate the catalyst. The reaction is carried out in a bateh reactor at a temperature sufficiently high that the adsorption constants of reactants and products are quite small. The reactor is charged with 0.1% eumene hydroperoxide, 90% N2, and 9.9% cumene at a pressure of 20 atm. The following data were obtained in a well-mixed batch reactor with a catalyst concentration of 1 kg/m, ... 

There have been notable shifts in raw materials for the manufacture of maleic anhydride and phenol. Made for many years by the oxidation of benzene, maleic anhydride now is made by a catalytic process from butane. The butane process was found to result in lower costs of operation as well as reduced environmental, safety, and health hazards. Another example is the manufacture of phenol, initially made from benzene or chlorobenzene. Subsequently, however, with large supplies of cumene from the catalytic reaction of benzene and propylene, production came to be dominated by cumene-derived phenol, which, requires a lower capital investment and offers reduced operating expenses as well as reduced environmental and safety problems. A novel... 

Cumene (isopropylbenzene) is presently produced fix>m benzene and propylene using either solid phosphoric acid or anhydrous aluminium chloride or zeolite as catalyst. Large amounts of m- and p- diisopropylbenzenes (DIPB) were produced as by-products from the above processes. Therefore, in order to study the activity of trifluoromediane-sulphonic acid (triflic acid) as catalyst to produce higher yield of cumene from DIPB isomers a series of isomerization and transalkylation reactions, of m- and p-isomers in benzene with different molar ratios 1 1 1, 1 3 1 and 1 6 1 of isomer to benzene to catalyst respectively with each isomer using triflic acid as catalyst, were carried out in liquid phase at room temperature and imder nitrogen atmospheric pressure. 

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