Propylene oxide industrial preparation

Catalysts. Silver and silver compounds are widely used in research and industry as catalysts for oxidation, reduction, and polymerization reactions. Silver nitrate has been reported as a catalyst for the preparation of propylene oxide (qv) from propylene (qv) (58), and silver acetate has been reported as being a suitable catalyst for the production of ethylene oxide (qv) from ethylene (qv) (59). The solubiUty of silver perchlorate in organic solvents makes it a possible catalyst for polymerization reactions, such as the production of butyl acrylate polymers in dimethylformamide (60) or the polymerization of methacrylamide (61). Similarly, the solubiUty of silver tetrafiuoroborate in organic solvents has enhanced its use in the synthesis of 3-pyrrolines by the cyclization of aHenic amines (62). 

PROPENE The major use of propene is in the production 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 oi polyurethane polymers. Cumene itself has no direct uses but rather serves as the starting material in a process that yields two valuable industrial chemicals acetone and phenol. 

The search for a new epoxidation method that would be appropriate for organic synthesis should also, preferably, opt for a catalytic process. Industry has shown the way. It resorts to catalysis for epoxidations of olefins into key intermediates, such as ethylene oxide and propylene oxide. The former is prepared from ethylene and dioxygen with silver oxide supported on alumina as the catalyst, at 270°C (15-16). The latter is prepared from propylene and an alkyl hydroperoxide, with homogeneous catalysis by molybdenum comp e ts( 17) or better (with respect both to conversion and to selectivity) with an heterogeneous Ti(IV) catalyst (18), Mixtures of ethylene and propylene can be epoxidized too (19) by ten-butylhydroperoxide (20) (hereafter referred to as TBHP). 

Only one of the approaches considered here, chain-extension with propylene oxide of hydroxypropyl lignins, allowed for the preparation of networks with substantial elongation at break. Typical of most polyurethanes, an increase in the elongation at break resulted in a corresponding decrease in modulus and strength. This represents the most complex modification procedure of those discussed, although process development could probably simplify this modification for adoption on industrial scale. 

In the polyurethane industry, the polymeric glycols are prepared by anionic polymerization of epoxides such as ethylene oxide and propylene oxide. Poly(tetra-methylene glycol), which was prepared by polymerization of tetrahydrofuran, was subjected to chain extension by reaction with diisocyanate (polyurethane formation) and with dimethyl terephthalate (polyester by alcoholysis). 

Methylcellulose solutions generally form gels at higher temperatures. The gelation temperature is increased when hydroxyethyl or hydroxypropyl groups are introduced into the methylcellulose (cf. Section 9.6.2). Hy-droxyethylmethylcellulose and hydroxypropylmethylcellulose are prepared industrially by the reaction of alkali cellulose first with ethylene oxide or propylene oxide and then with methyl chloride. Similarly, hydroxyethyl-ethylcellulose is prepared by consecutive ethylene oxide and ethyl chloride treatments. Cellulose ethers with both methyl and ethyl groups have also been manufactured. 

New synthetic processes for the preparation of established products were also industrially developed in Japan the manufacture of methyl methacrylate from C4 olefins, by Sumitomo and Nippon Shokubai in France, the simultaneous production of hydroquinone and pyro-catechin through hydrogen peroxide oxidation of phenol by Rhone-Poulenc in the United States the production of propylene oxide through direct oxidation of propylene operating jointly with styrene production, developed by Ralph Landau and used in the Oxirane subsidiary with Arco, which the latter fully took over in 1980 in Germany and Switzerland, the synthesis of vitamin A from terpenes, used by BASF and Hoffmann-La Roche. 

Alkene epoxidation is a very useful reaction in industry and organic s)mthesis. The resultant epoxides are essential precursors in the s)mthesis of various important substances like plasticizers, perfumes, and epoxy resins [1]. For example, over 5,000,000 and 70,000 metric tonnes of propylene and butene oxides, respectively, are produced per year [2]. Current commercial production of propylene oxide (PO) usually employs the chlorohydrin process or the Halcon process, which gives rise to disposal problem for the resultant salts or large amounts of coproducts. As a result of increasing stringent enviromnent legislation, there is currently much interest in the research and development of environmentally friendly methods for preparation of PO without any coproduct. 

One oxidation reaction that is of large industrial relevance is the oxidative dehydrogenation of light alkanes to the corresponding alkene (Scheme 3.20). This reaction has been reported to be promoted by r-GO as catalyst [29]. The importance of this reaction type is particularly high for the industrial preparation of propene from propane and butenes from butanes. Both reactions are carried out industrially in very large scale, because propene is the monomer of polypropene and also the starting material of propylene oxide, acrylonitrile, and other base chemicals. Butenes are mainly used for the preparation of 1,3-butadiene that is one of the major components of rubbers and elastomers. 

Propylene oxide is an allergic and irritant agent, used as a solvent and raw material in the chemical industry as starting material and intermediate for a broad spectrum of polymers. It can be used as a dehydrating agent for the preparation of slides in electron microscopy. Occupational dermatitis was also reported while using a skin disinfectant swab. 

Poly (2-hydroxypropyl. Me) ether Hydro-xypropyl methyl cellulose. HPMC. E463. Hypromellose, USAN. Hydroxypropyl-methylcellulose, JAN. Cellulose hydro-xypropyl methyl ether, BAN, INN [9(X)4-65-3] Prepared by etherification of alkaline cellulose with methyl chloride and propylene oxide. Commercial samples have methyl DS values of 1.1-2.0 and hydroxypropyl MS values of 0.1 - 1.0. Thickening and binding agent with widespread industrial uses in adhesives, building products, films, protective creams and colloids. Approved for food use in US and EU. Used in deep fried batters. Shows better water solubility and electrolyte tolerance than methylcellulose. Component of artificial tears. 

In general, commercial polyether polyols are limited in monomer composition to propylene oxide, ethylene oxide, butylene oxide and tetrahydrofuran. Industrial polyester polyols, many of which are the condensation products of organic acids and alcohols, may be prepared by a great many more combinations of monomers, and thus add to the potential versatility of polyurethane products. The commonest are based on adipamides ... 

Amine-terminated poly(alkylene oxide)s have been made and used in industry for over half a century. These compounds can be prepared in various ways. Lee and Winfrey (54) describe a process in which poly (propylene oxide)s are converted into diamines by reaction with anhydrous ammonia, hydrogen and anhydrous ammonia, or ammonium hydroxide in the presence of a Raney nickel catalyst. In the following... 

Other major industrial applications for hydrogen peroxide include the manufacture of sodium percarbonate and sodium perborate, used as mild bleaches in laundry detergents. It is used in the production of certain organic peroxides such as dibenzoyl peroxide, used in polymerisations and other chemical processes. Hydrogen peroxide is also used in the production of epoxides such as propylene oxide. Reaction with carboxylic acids produces a corresponding peroxy acid. Peracetic acid and meta-chloroperoxybenzoic acid (commonly abbreviated mCPBA) are prepared from acetic acid and /weto-chlorobenzoic acid, respectively. The latter is commonly reacted with alkenes to give the corresponding epoxide. 

During the history of a half century from the first discovery of the reaction (/) and 35 years after the industrialization (2-4), these catalytic reactions, so-called allylic oxidations of lower olefins (Table I), have been improved year by year. Drastic changes have been introduced to the catalyst composition and preparation as well as to the reaction process. As a result, the total yield of acrylic acid from propylene reaches more than 90% under industrial conditions and the single pass yield of acrylonitrile also exceeds 80% in the commercial plants. The practical catalysts employed in the commercial plants consist of complicated multicomponent metal oxide systems including bismuth molybdate or iron antimonate as the main component. These modern catalyst systems show much higher activity and selectivity... 

A method of considerable industrial importance for the large-scale preparation of ethylene oxide is direct oxidation of ethylene at elevated temperatures over a suitably prepared metallic silver catalyst. Although the reaction may be written aa indicated in Eq. (09), in actual practice only about half the ethylene is converted into ethylene oxide, the remainder being oxidized further to carbon dioxide and water. In spite of this seeming disadvantage, catalytic oxidation appears at present to bo economically competitive with chlorohydrin formation aa a means for the commercial production of ethylene oxide.MM Unfortunately, other olefins, such as propylene and mo-butylene for example, apparently give only carbon dioxide and water under the usual oxidation conditions,1310 so that until now the patent hu balance ethylene oxide has been the only representative accessible by tins route. 

ACRYLIC ACID AND DERIVATIVES. [CAS 79-10-7]. Acrylic acid (propenoic acid) was first prepared in 1847 by air oxidation of acrolein. Interestingly, after use of several other routes over the past half century, it is tins route, using acrolein from the catalytic oxidation of propylene, that is currently the most favored industrial process. 

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