Alkylation using propylene

Propylene could be used as an alkylating agent for aromatics. An important reaction with great commercial use is the alkylation of benzene to cumene for phenol and acetone production. The reaction is discussed in Chapter 10. 

Katzer, J. R., and Schuit, G. C., Chemistry of Catalytic Processes, McGraw-Hill Book Company, 1979, p. 349. 

Mirhach, M., and Tayim, H., Catalysis in Petrochemical Processes, Kluwer Academic Publishers, Dordrecht, The Netherlands, 1989, pp. 93-94. 

The Chemistry of Petrochemical Reactions, Gulf Puhlishing Co., Houston, 1955, p. 76. 

Synfuels Hydrocarbons of the Future, PennWell Publishing Co., Tulsa, OK, 1982, p. 20. 

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With HE as catalyst, mechanism 4 can be promoted by higher temperatures and also higher isobutane/ olefin ratios.f Plant operators using HE often deliberately promote mechanism 4 for alkylations using propylene or 1-butene to produce higher-quality alkylates and more TMPs. Operating costs, however, increase because of increased isobutane consumption and higher costs to recover and recycle the additional unreacted isobutane. 

Mechanism 4 is of importance whenever propane, n-butane, and n-pentane are obtained during alkylation using propylene, n-butenes, and n-pentenes, respectively, as olefin feeds. Mechanism 4 is sometimes referred to as hydrogen transfer or self-alkylation of isobutane. The overall reaction is often depicted as follows (1) ... 

The most widely used process for the production of phenol is the cumene process developed and Hcensed in the United States by AHiedSignal (formerly AHied Chemical Corp.). Benzene is alkylated with propylene to produce cumene (isopropylbenzene), which is oxidized by air over a catalyst to produce cumene hydroperoxide (CHP). With acid catalysis, CHP undergoes controUed decomposition to produce phenol and acetone a-methylstyrene and acetophenone are the by-products (12) (see Cumene Phenol). Other commercial processes for making phenol include the Raschig process, using chlorobenzene as the starting material, and the toluene process, via a benzoic acid intermediate. In the United States, 35-40% of the phenol produced is used for phenoHc resins. 

Benzene is alkylated with propylene to yield cumene (qv). Cumene is catalytically oxidized in the presence of air to cumene hydroperoxide, which is decomposed into phenol and acetone (qv). Phenol is used to manufacture caprolactam (nylon) and phenoHc resins such as bisphenol A. Approximately 22% of benzene produced in 1988 was used to manufacture cumene. 

MethylceUulose is made by reaction of alkaU ceUulose with methyl chloride until the DS reaches 1.1—2.2. HydroxypropyhnethylceUulose [9004-65-3], the most common of this family of products, is made by using propylene oxide in addition to methyl chloride in the reaction MS values of the hydroxypropyl group in commercial products are 0.02—0.3. Use of 1,2-butylene oxide in the alkylation reaction mixture gives hydroxybutyhnethylceUulose [9041-56-9, 37228-15-2] (MS 0.04—0.11). HydroxyethyhnethylceUulose [903242-2] is made with ethylene oxide in the reaction mixture. 

Toxicity and Environmental Fate Information for Propylene CAS 115-07-1 Sourtes. Propylene (propene) is one of the light ends formed during catalytic and thermal cracking and coking operations, it is usually collected and used as a feedstock to the alkylation unit. Propylene is volatile and soluble in water making releases to both air and water significant. 

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. 

Isopropylbenzene (A) is alkylated with propylene (P) using HF catalyst. The mono (B), di (C), tri (D) and tetra (E) derivatives are formed. Relative specific rates are given by Rodiguin Rodiguina (Consecutive Chemical Reactions, 1964) for the case of a large excess of propylene which makes the reactions pseudo first order. The relative specific rates used here are kx = 1.0, k2 = 0.5, k3 = 0.3 and k4 0.2. The system of linear differential... 

In this work, the goal is to design a control function in such a manner that neither the reaction heat nor kinetic nor mass transfer terms are required for stabilizing temperature. The scheme provides an estimated value of the heat generation from energy balance. Alkylation isobutane/propylene using sulfuric... 

The related manufacture of cumene (isopropylbenzene) through the alkylation of benzene with propylene is a further industrially important process, since cumene is used in the synthesis of phenol and acetone. Alkylation with propylene occurs more readily (at lower temperature) with catalysts (but also with hydrogen fluoride and acidic resins) similar to those used with ethylene, as well as with weaker acids, such as supported phosphoric acid (see further discussion in Section 5.5.3). 

Alkylation processes usually combine isobutane with an alkene or with mixed alkene streams (C3-C5 olefins from FCC units). The best octane ratings are attained when isobutane is alkylated with butylenes. Alkylation of higher-molecular-weight hydrocarbons (>C5) is less economic because of increased probability of side reactions. Phillips developed a technology that combines its triolefin process (metathesis of propylene to produce ethylene and 2-butenes) with alkylation since 2-butenes yield better alkylate than propylene.290 Since ethylene cannot be readily used in protic acid-catalyzed alkylations, a process employing AICI3 promoted by water was also developed.291... 

Mesitylene was alkylated with propylene or 2-propanol in supercritical CO2 using Deloxane, a polysiloxane-supported solid acid catalyst in a continuous flow reactor.406 Monoisopropylation with 100% selectivity occurred with 2-propanol. 

Although organochromium catalysts are not well characterized, organochromium compounds are thought to bind to the support by reaction with surface hydroxyls as other types do. When Cr(allyl)3 or Cr(allyl)2 is used, propylene is released (59,60). Chromocene loses one ring (52-55), and / -stabilized alkyls of chromium lose the alkane (81). 

Extraction with SO,., suggested in 1907 to purify kerosene, applied to secure aromatics from reformate (early 1940s) Alkylation of propylene with benzene using solid H5PO4 catalyst to make cumene (early to mid-1940s)... 

Isopropylbenzene (A) is alkylated with propylene (P) using HF catalyst. The mono (B), di (C), tri (D) and tetra (E) derivatives are formed. Relative... 

In the production of aviation and motor alkylates, both propylene and amylenes are inferior feed stocks when compared with the butylenes. These feeds produce lighter and heavier alkylates, respectively, than the butylenes, both alkylates having a lower octane than the trimethylpentane produced from butylenes. Also, acid consumption when sulfuric acid catalyst is used is two or more times as great with propylene or amylenes than with butylenes. Hydrofluoric acid catalyst, on the other hand, is not consumed at a higher rate on propylene and amylene feeds but does make a higher percentage of tar. 

In this paper, a new test reaction is suggested for characterizing the effective pore size of larger pore (12-membered rings or above) molecular sieve materials. Metadiisopropylbenzene is alkylated with propylene and the weight ratio of 1,3,5- to 1,2,4-triisopropylbenzene formed is calculated. This ratio is used to characterize the effective void space size of molecular sieves. 

Alkylates made specifically as feedstocks for synthetic petroleum sulphonates are typically long chain (average C chain > 16) and may use propylene oligomers which result in branched chains. Naphthalene products use the same propylene technology but tend to shorter chains (di-isopropylnaphthalene, di-nonylnaphthalene). 

Paushkin, Topchiev, and co-workers have been studying polymerization and alkylation using BF3 in combination with H3P04 as a preferred catalyst (287,394,395,397,399,402). The acidity of the component added to BF3 is thought to increase the activity of the catalyst. Propylene and isobutylene were among the olefins which were investigated (398,401). 

Aluminum alkyls used in making organometallic catalysts and as initiators for processes such as ethylene-propylene rubber, polybutadiene, low-pressure polyethylene, and ethylene oligomerization to make alpha-olefins and C6-C18 alcohols... 

Absorption. In the absorption step as much as possible of the olefin should be converted to dialkyl sulfate. The dialkyl sulfates are quite soluble in hydrocarbons above about 40° F, whereas the alkyl acid sulfates are not. Propylene is the preferred olefin, and n-butylenes may be used. Propylene has been used commercially. Although an exhaustive study was not made, the use of a butylene feed containing isobutylene gave poor results. Isobutylene results in a considerable loss of acid and also isobutylene. About 10-25% of the total olefin used in SARP is reacted in the absorber, assuming a net acid consumption of about... 

Gulf s commercial grade benzene (99" "% benzene) and alkylation grade propylene (73-75% propylene and 27-25% propane) were used in all the work. 

A more recent method for the activation of epoxides, especially in reactions with alkylcoppers and related species, is to add boron trifluoride etherate to the system. Such additions will also facilitate alky llithium additions to epoxides, two specific examples being homologation of the pyridylindole (141) into the hydroxyethyl derivative (142) " and alkylation of the sulfone (73) using propylene oxide, which requires the presence of BF3 if a good yield, in this example 80%, of the desired product (143) is to be obtained, "... 

An elegant demonstration of the above mechanism has been provided by Zambelli et al., who showed that the first insertion of propylene into a Ti-CH3 bond generated by chain transfer with A1 alkyl using the system TiCl3/Al(CH3) 3 is not stereospecific, whereas the second insertion (i.e., into Ti-isobutyl) is stereospecific. 

Other more prominent process for production of resorcinol is through alkylation of benzene using propylene in such as a way that alkylation is done carefully to introduce isopropyl in 1 and 3 position, i.e., diisopropyl benzene which is then converted to resorcinol using a similar process of phenol from isopropyl benzene or cresols from iosopropyl toluene. 

However, from economic and environmental point of view both USA and Japan use the propylene alkylation route, as this method of manufacture is more amenable to continuous operations with recycle stream. The alkylation with propylene and isomerization are carried out upto 240° C with traditional solid phosphoric acid (SPA) catalyst and more recently with anhydrous AICI3 catalyst. Final catalytic oxidation at 90-110°C gives the hydroperoxide, as in cumene and cymene processes, which on cleavage with dilute sulfuric acid gives 2-naphthol in high overall yield. [53]... 

Going a step further, the plant can be made more versatile so that other alkylated cresols can be produced. One classical example is manufacture of thymol based on alkylation of m-cresol using propylene. Only major difference in the production of BHT vis-a-vis thymol is that for making BHT via butylation of p-cresol one uses a Lowery-Bornstead acid catalyst such as H2SO4, whereas for thymol production via pro-pylation of meto-cresol one has to use a Lewis acid such as... 

The reaction pathway of benzene alkylation with propylene catalyzed by acids is very similar to that already reported for EB. The main difference is represented by the tendency of cumene to isomerize to n-propylbenzene, which is thermodynamically more stable at increased temperature. Also, cumene can undergo further alkylation to diisopropylbenzene (DIPB), which could be recovered by transalkylation with benzene to give cumene. The transalkylation reaction requires a higher temperature than the related alkylation. In addition, not all of the alkylation catalysts are suitable for transalkylation. Beta or dealuminated mordenite are suitable catalysts for transalkylation. The first industrial demonstrations of cumene technologies based on zeolite catalysts were started-up in 1996 by Mobil-Raytheon, EniChem and UOP, independently. In 2001, worldwide, 14 cumene units were already operating with zeolite catalysts. Around 98% ofcumene is used to produce phenol and expected world production of cumene in 2008 is around 9 million tons. For cumene, among the 40 units in the world (2004), 14 cumene plants were in operation with zeolite catalysts [222]. Today over 70% of cumene plants use a zeolite as the catalyst. 

According to the mechanism, the active center is formed by the interaction of aluminum alkyl with an octahedral vacancy around Ti. For or-TiCls catalyst the formation of active center can be represented as shown in Fig. 9.3. To elaborate, the five-coordinated Ti on the surface has a vacant J-orbital, represented by -Q, which facilitates chemisorption of the aluminum alkyl followed by alkylation of the Ti " ion by an exchange mechanism to form the active center TiRCU-Q. The vacant site at the active center can accommodate the incoming monomer unit, which forms a r-complex with the titanium at the vacant inserted into the Ti-alkyl bond. The sequence of steps is shown in Fig. 9.4 using propylene as the monomer. 

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