Propylene oxide chemical process

In 2008, BASF and Dow Chemical successfully started the first commercial production plant based on the novel hydrogen peroxide to propylene oxide (HPPO) process. The plant is located in Antwerp, Belgium and the initial annual capacity is around 300 000 tons. A second plant based on this technology will start production in 2011 in Map Ta Phut, Thailand. 

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... 

Synthesis. The total aimual production of PO in the United States in 1993 was 1.77 biUion kg (57) and is expected to climb to 1.95 biUion kg with the addition of the Texaco plant (Table 1). There are two principal processes for producing PO, the chlorohydrin process favored by The Dow Chemical Company and indirect oxidation used by Arco and soon Texaco. Molybdenum catalysts are used commercially in indirect oxidation (58—61). Capacity data for PO production are shown in Table 1 (see Propylene oxide). 

Propylene oxide [75-56-9] (methyloxirane, 1,2-epoxypropane) is a significant organic chemical used primarily as a reaction intermediate for production of polyether polyols, propylene glycol, alkanolamines (qv), glycol ethers, and many other useful products (see Glycols). Propylene oxide was first prepared in 1861 by Oser and first polymerized by Levene and Walti in 1927 (1). Propylene oxide is manufactured by two basic processes the traditional chlorohydrin process (see Chlorohydrins) and the hydroperoxide process, where either / fZ-butanol (see Butyl alcohols) or styrene (qv) is a co-product. Research continues in an effort to develop a direct oxidation process to be used commercially. 

The chlorohydrin process involves reaction of propylene and chlorine in the presence of water to produce the two isomers of propylene chlorohydrin. This is followed by dehydrochlorination using caustic or lime to propylene oxide and salt. The Dow Chemical Company is the only practitioner of the chlorohydrin process in North America. However, several companies practice the chlorohydrin process at more than 20 locations in Germany, Italy, Bra2il, Japan, Eastern Europe, and Asia. 

The hydroperoxide process involves oxidation of propjiene (qv) to propylene oxide by an organic hydroperoxide. An alcohol is produced as a coproduct. Two different hydroperoxides are used commercially that result in / fZ-butanol or 1-phenylethanol as the coproduct. The / fZ-butanol (TBA) has been used as a gasoline additive, dehydrated to isobutjiene, and used as feedstock to produce methyl tert-huty ether (MTBE), a gasoline additive. The 1-phenyl ethanol is dehydrated to styrene. ARCO Chemical has plants producing the TBA coproduct in the United States, Erance, and the Netherlands. Texaco has a TBA coproduct plant in the United States. Styrene coproduct plants are operated by ARCO Chemical in the United States and Japan, Shell in the Netherlands, Repsol in Spain, and Yukong in South Korea. 

Dehydrochlorination to Epoxides. The most useful chemical reaction of chlorohydrins is dehydrochlotination to form epoxides (oxkanes). This reaction was first described by Wurtz in 1859 (12) in which ethylene chlorohydria and propylene chlorohydria were treated with aqueous potassium hydroxide [1310-58-3] to form ethylene oxide and propylene oxide, respectively. For many years both of these epoxides were produced industrially by the dehydrochlotination reaction. In the past 40 years, the ethylene oxide process based on chlorohydria has been replaced by the dkect oxidation of ethylene over silver catalysts. However, such epoxides as propylene oxide (qv) and epichl orohydrin are stiU manufactured by processes that involve chlorohydria intermediates. 

The most important chemical reaction of chi orohydrin s is dehydrochloriaation to produce epoxides. In the case of propylene oxide. The Dow Chemical Company is the only manufacturer ia the United States that still uses the chlorohydrin technology. In 1990 the U.S. propylene oxide production capacity was hsted as 1.43 x 10 t/yr, shared almost equally by Dow and Arco Chemical Co., which uses a process based on hydroperoxide iatermediates (69,70). More recentiy, Dow Europe SA, aimounced a decision to expand its propylene oxide capacity by 160,000 metric tons per year at the Stade, Germany site. This represents about a 40% iacrease over the current capacity (71). 

Epoxides such as ethylene oxide and higher olefin oxides may be produced by the catalytic oxidation of olefins in gas-liquid-particle operations of the slurry type (S7). The finely divided catalyst (for example, silver oxide on silica gel carrier) is suspended in a chemically inactive liquid, such as dibutyl-phthalate. The liquid functions as a heat sink and a heat-transfer medium, as in the three-phase Fischer-Tropsch processes. It is claimed that the process, because of the superior heat-transfer properties of the slurry reactor, may be operated at high olefin concentrations in the gaseous process stream without loss with respect to yield and selectivity, and that propylene oxide and higher... 

Daicel A process for making propylene oxide by oxidizing propylene with peroxyacetic acid. The peroxyacetic acid is made by reacting together ethyl acetate, acetaldehyde, a metal ion catalyst, and air. Developed by Daicel Chemical Industries, Japan from 1966 and commercialized from 1969 to 1980. See also Propylox. 

Hydronium ion, 14 23 Hydroperoxidates, 18 411 Hydroperoxide process, for propylene oxide manufacture, 20 798, 801-806 Hydroperoxides, 14 281, 290-291 18 427-436 alkylation of, 18 445 a-oxygen-substituted, 18 448-460 chemical properties of, 18 430 433 decomposition of, 14 279 18 431-432 liquid-phase epoxidation with, 10 656 physical properties of, 18 427-430 preparation by autoxidation, 18 434 synthesis of, 18 433-435 Hydrophile-lipophile balance system,... 

There are some ways to evaluate environmental burden in chemical synthetic processes. The atom economy is the fraction of the atoms in the product to the fraction of all atoms in the reactants. The E factor is the ratio of the mass of all waste to the mass of product. For the following reaction concerning the production of propylene oxide, calculate the theoretical atom economy and E factor. 

You have to talk about propylene oxide and propylene glycol after ethylene oxide and glycol. Its not that the chemical configurations are so similar (they are), or that the process chemistry is about the same (it is). The Fact is that much of the propylene oxide is now made in plants originally designed and constructed to produce EO, not PO. As you read in the last chapter, the chlorohydrin route to EO was abandoned by the 1970s in favor of direct oxidation. At the same time, the EO producers found that the old EO plants were suitable for the production of PO and certainly the cheapest hardware available to satisfy growing PO demands. 

The most recent entrant-to the. club of commodity chemicals is 1,4-butanediol (BDO), a petrochemical used in some of the more specialized applications such as chemical intermediates for the production of tetrahydro-furane and gama-butyrolactone, polybutylene terephthalate, and the more familiar polyurethanes. Traditionally, the Reppe process was the primary route to BDO, based bn acetylene and formaldehyde feeds. More recently, the share of BDO from butane and propylene oxide based production has grown rapidly. 

Acetylene is a tricky chemical feedstock. It is extremely reactive (and explosive) and impractical to transport. Generally, the industrial processes that use acetylene are close to the acetylene-generating source. Despite all the drawbacks, the Reppe process was for a half century the preferred process for EDO, but now the growth in EDO is being taken by the propylene oxide (PO) and butane feedstock routes. 

Olefin epoxidation is an important industrial domain. The general approach of SOMC in this large area was to understand better the elementary steps of this reaction catalyzed by silica-supported titanium complexes, to identify precisely reaction intermediates and to explain catalyst deachvahon and titanium lixiviation that take place in the industrial Shell SMPO (styrene monomer propylene oxide) process [73]. (=SiO) Ti(OCap)4 (OCap=OR, OSiRs, OR R = hydrocarbyl) supported on MCM-41 have been evaluated as catalysts for 1-octene epoxidation by tert-butyl hydroperoxide (TBHP). Initial activity, selechvity and chemical evolution have been followed. In all cases the major product is 1,2-epoxyoctane, the diol corresponding to hydrolysis never being detected. 

Another example of a famous organic chemical reaction being replaced by a catalytic process is furnished by the manufacture of ethylene oxide. For many years it was made by chlorohydrin formation followed by dehydrochlorination to the epoxide. Although the chlorohydrin route is still used to convert propylene to propylene oxide, a more efficient air epoxidation of ethylene is used and the chlorohydrin process for ethylene oxide manufacture has not been used since 1972. 

Chlorine (from the Greek chloros for yellow-green ) is the most abundant halogen (0.19 w% of the earth s crust) and plays a key role in chemical processes. The chlor-alkali industry has been in operation since the 1890s and improvements in the technology are still important and noticeable, for example, the transition from the mercury-based technology to membrane cells [60]. Most chlorine produced today is used for the manufacture of polyvinyl chloride, chloroprene, chlorinated hydrocarbons, propylene oxide, in the pulp and paper industry, in water treatment, and in disinfection processes [61]. A summary of typical redox states of chlorine, standard potentials for acidic aqueous media, and applications is given in Scheme 2. 

The formation of epoxides is synthetically a very important transformation. The indirect epoxidation of olefins (see Eq. 7) in the presence of electrogenerated chlorine (or bromine) [95] is a commercial process in which chlorine is recycled and not part of the product. The products such as propylene oxide are key intermediates in many further chemical processes. 

Propylene is a colorless, flammable gas that follows ethylene as the second simplest alkene hydrocarbon. It has an odor similar to garlic and has wide use in the chemical industry as an intermediate in the synthesis of other derivatives such as polypropylene, propylene oxide, isopropyl alcohol, acetone, and acrylonitrile. The production of propylene is similar to ethylene and is obtained through steam cracking of hydrocarbon feedstocks. Steam cracking is a process used to break molecules into smaller molecules by injecting the catalysts with steam. 

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