Chemicals continued propylene oxide

Propylene requirements for acrylates remain small compared to other chemical uses (polypropylene, acrylonitrile, propylene oxide, 2-propanol, and cumene for acetone and phenol). Hence, cost and availabihty are expected to remain attractive and new acrylate capacity should continue to be propylene-based until after the turn of the century. 

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. 

Production of propylene oxide in the United States in 1993 was estimated at 1,240,000 metric tons, and as having a 10-yr average aimual growth rate of 3.9% (229). Projections were for continued growth at about 4%/yr. Producers include Dow Chemical s chlorohydrin plants in Ereeport, Texas, and Plaquemine, Louisiana, and ARCO Chemical s hydroperoxide plants in Bayport and Chaimelview, Texas. Texaco started up a 180,000-t/yr plant in Port... 

Propylene oxide (PO) is a versatile chemical intermediate used in a wide range of industrial and commercial products. Current world production is over 6 million metric torts a year. While several processes exist, the Shell Chemicals companies have derived a strong competitive advantage by using and continually developing their proprietary styrene monomer propylene oxide (SMPO) technology, a process in which propylene and ethylbenzene (EB) are converted into PO and styrene monomer (SM), respectively. Worldwide, there are now five world-scale SMPO plants based on Shell technology, the most recent one started up in 2006 in China. 

Mixtures of polyethyleneglycols (and ethylene oxide-propylene oxide copolymers), a base and a peroxide (or other radical initiators) allow the preparation of several reagents which, suitably formulated according to their different use, are able to degrade the chemically stable chlorinated aromatics. Such a method, called CDP-Process, is active on TCDD and can be applied in different ways as an example, the reagent, when immobilized on a solid bed, allows the continuous-flow decontamination of mineral oils containing PCB this is useful for the decontamination of an electrical transformer during operation. Another reported example is the decontamination of surfaces contaminated by PCB or PCB fires (where PCDF and PCDD are also present). 

Isopropanol is used in the production of other chemicals such as derivative ketones, isopropylamines, and isopropyl esters. The use of isopropanol in the production of monoisopropylamine for herbicides (primarily glyphosate) continues to be the fastest growing segment (Anonymous 2001b). A minor use for isopropanol is to serve as a feedstock for the production of acetone to meet the demand in excess of the coproduct acetone from phenol production. However, isopropanol is also produced from crude acetone, which is generated as a by-product of propylene oxide manufacture (Anonymous 2001b). 

Because CO2 is a nontoxic, nonflammable, and inexpensive substance, there is continued interest in its activation with transition metal complexes and its subsequent use as a Cl feedstock (1,2). Even though CO2 is used to make commodity chemicals such as urea, salicylic acid and metal carbonates, efficient catalyst systems that exploit this feedstock as a comonomer in polymerization reactions have been elusive (3,4). One reaction that has been considerably successful is that of CO2 with epoxides to yield aliphatic polycarbonates (Scheme 1) (5). Of particular significance is the synthesis of poly(propylene carbonate) (PPC), because the starting materials—propylene oxide (PO) and CO2—are inexpensive. 

More than a decade after the publication of the MoVNb catalyst system, scientists at Mitsubishi Chemical reported that modifying this family of mixed metal oxides with Te produced a catalyst for the amoxidation of propane to acrylonitrile [4] and the oxidation of propane to acrylic acid [5], Modification of the Union Carbide catalyst system with Te was probably not a random choice as it is a known propylene activator [5 b] and the molybdate phase TeMoO oxidizes propylene into acrolein and ammoxidizes propylene to acrylonitrile [6], a key intermediate in the commercial production of acrylic acid using Mo-based oxides. Significant efforts to optimize this and related mixed metal oxides continues for the production of both acrylic acid and acrylonitrile, with the main participants being Asahi, Rohm Hass, BASF, and BP. 

Other chemical products, often referred to as connnodity chemicals, are required in large quantities. These are often intermediates in the manufacture of specialty chemicals and industrial and consumer products. These include ethylene, propylene, butadiene, methanol, ethanol, ethylene oxide, ethylene glycol, ammonia, nylon, and caprolactam (for carpets), together with solvents like benzene, toluene, phenol, methyl chloride, and tetrahydrofuran, and fuels like gasoline, kerosene, and diesel fuel. These are manufactured in large-scale processes that produce billions of pounds annually in continuous operation. Since they usually involve small well-defined molecules, the focus of the design is on the process to produce these chemicals from various raw materials. 

Exterior door handles are another application that has turned to plastics to balance chemical resistance and mechanical properties. Many filled thermoplastics such as blends of PC and polybutylene terephthalate (PBT), polyethylene terephthalate (PET), and nylon have been tried or used in this application, with nylon as the clear wirmer. Exterior mirror housings likewise use many thermoplastic solutions such as ABS, PC/ABS, blends of polyphenylene oxide (PPO) and polystyrene (PS), nylon, blends of PP and ethylene propylene diene monomer (EPDM), and weatherable ABS. Again, nylon clearly dominates this application in terms of volume. Many other exterior parts continue to adopt thermoplastic solutions. Figure 14 shows an impingement shield constructed from LGF PP. 

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