Oxidative plants

Two explosions, on November 14, 1987, at the largest butane Hquid-phase oxidation plant resulted in 3 deaths and 37 people injured (54). The plant. 

The modified Reppe process was installed by Rohm and Haas at thek Houston plant in 1948 and later expanded to a capacity of about 182 X 10 kg/yr. Rohm and Haas started up a propylene oxidation plant at the Houston site in late 1976. The combination of attractive economics and improved product purity from the propylene route led to a shutdown of the acetylene-based route within a year. 

In the former USSR, there reportedly are two technologies in use one is old anthrahydroquinone autoxidation technology and the other is closed-loop isopropyl alcohol oxidation technology. Production faciUties include several smaller, 100-150-t/yr isopropyl alcohol oxidation plants and a larger, 15,000-t/yr plant, which reportedly is being expanded to 30,000-t/yr. Differences in this technology as compared to the Shell Chemical Co. process are the use of oxygen-enriched air in the oxidation step and, catalytic reduction of the coproduct acetone back to isopropyl alcohol per equation 21. 

Although this process has not been commercialized, Daicel operated a 12,000-t/yr propylene oxide plant based on a peracetic acid [79-21-0] process during the 1970s. The Daicel process involved metal ion-catalyzed air oxidation of acetaldehyde in ethyl acetate solvent resulting in a 30% peracetic acid solution in ethyl acetate. Epoxidation of propylene followed by purification gives propylene oxide and acetic acid as products (197). As of this writing (ca 1995), this process is not in operation. 

AH ethylene oxide direct-oxidation plants are based on the original process chemistry discovered by Lefort in 1931 (7,8). The main reaction is as follows ... 

Air-Based Direct Oxidation Process. A schematic flow diagram of the air-based ethylene oxide process is shown in Figure 2. Pubhshed information on the detailed evolution of commercial ethylene oxide processes is very scanty, and Figure 2 does not necessarily correspond to the actual equipment or process employed in any modem ethylene oxide plant. Precise information regarding process technology is proprietary. However, Figure 2 does illustrate all the saUent concepts involved in the manufacturing process. The process can be conveniently divided into three primary sections reaction system, oxide recovery, and oxide purification. 

Energy recovery has been standard practice from the early days of ammonia oxidation plants with escalating energy costs energy recovery is becoming increasingly important. 

On June 1, 1974, a vapor cloud explosion destroyed the 70,CKX) tons per year, Flixborough Nyprocyclohexane oxidation plant killing 28 people. Other plants on the site were seriously damaged or destroyed and the site was destroyed. 

One Dies in Union Carbide Ethylene Oxide Plant Explosion ... 

Figure 7-8. The ethylene oxide plant after the fire and explosioti. (Photo courtesy of BP Chemicals Limited.)...

An explosion occurred in a vapor-phase hydrocarbon oxidation plant, injuring ten people and seriously damaging the plant, despite the fact that it was fitted with a protective system that measured the oxygen content and isolated the oxygen supply if the concentration approached the flammable limit. 

An ethylene oxide plant tripped, and a light on the panel told the operator that the oxygen valve had closed. Because the plant was going to be restarted immediately, he did not close the hand-operated isolation valve as well. Before the plant could be restarted, an explosion occurred. The oxygen valve had not closed, and oxygen continued to enter the plant (Figure 14-5). 

Britton, L. G. 1990. Thermal Stability and Deflagration of Ethylene Oxide. Plant/Operations Progress, 9(2). 

Partial methane oxidation comprises very high rates so that high space-time yields can be achieved (see original citations in [3]). Residence times are in the range of a few milliseconds. Based on this and other information, it is believed that syngas facilities can be far smaller and less costly in investment than reforming plants. Industrial partial oxidation plants are on the market, as e.g. provided by the Syntroleum Corporation (Tulsa, OK, USA). Requirements for such processes are operation at elevated pressure, to meet the downstream process requirements, and autothermal operation. 

Hutcheson SW, Buchanan BB. Polyphenol oxidation by Viciafaba chloroplast membranes studies on the latent membrane-bound polyphenol oxidase and on the mechanism of photochemical polyphenol oxidation. Plant Physiol 1966 66 1150-1154. 

Partial oxidation (POX), 13 844 catalytic aerogels for, l 763t economic process of, 13 781-783 of hydrocarbons, 13 780-783 Partial oxidation facility, 13 792—793 Partial oxidation plants, 13 775-776 Partial oxidation units, 13 782... 

The process was commercially so superior to the chlorohydrin route, that by the 1970s, the new chemistry had completely replaced the old. Adding some momentum to this transition was the fact that the obsolete and abandoned chlorohydrin plants could be readily converted to propylene oxide plants. The silver bullet for that process has yet to be found. 

Dugger, W. M., Jr., O. C. Taylor, E. Cardiff, and C. R. Thompson. Stomata action in plants as related to damage from photochemical oxidants. Plant Physiol. 37 487-491, 1%2. 

Rossiter, G. Anamax Twin Buttes oxide plant operating experience-first year. Presented at the Arizona Section, AIME, Hydrometallurgical Division, Spring, 1976. 

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