Steam commercial operations

Multistage Systems The majority of steam-jet systems being currently instaUed are multistage. Up to five stage systems are in commercial operation. 

NOTE Almost all types of commercial or industrial boilers, of whatever type, size, and application, must be provided with fully softened FW as an absolute minimum form of external water treatment. This requirement includes electrical resistance boilers. Probable exceptions to this rule are HW heating boilers and steam boilers operating at below 15 psig and receiving in excess of 95% returned condensate. 

Koppers-Totzek A coal gasification process using an entrained bed. The coal is finely ground and injected in a jet of steam and oxygen into a circular vessel maintained at 1,500°C. Reaction is complete within one second. The ash is removed as a molten slag. The process was invented by F. Totzek at Heinrich Koppers, Essen, and further developed by Koppers Company in Louisiana, MO, under contract with the U.S. Bureau of Mines. The first commercial operation was at Oulu, Finland, in 1952 by 1979, 53 units had been built. Most of the plants are operated to produce a hydrogen-rich gas for use in ammonia synthesis. Developed by Lurgi. See also PRENFLO. 

In its present commercial operations Sasol uses two types of reactors. In the fixed bed "low" temperature Arge reactors the gas enters at the top (see Figure 2). The catalyst is packed into the narrow tubes. The FT reaction heat is absorbed by the water surrounding the tubes and steam is generated. The desired reactor temperature is maintained by controlling the steam pressure above the water jacket. The catalyst formulation and the reactor process conditions are set for the maximum production of high quality paraffinic waxes. Only the Sasol One plant utilizes these reactors. 

Azeotropic Distillation. The concept of azeotropic distillation is not new. The use of benzene to dehydrate ethyl alcohol and butyl acetate to dehydrate acetic acid has been in commercial operation for many years. However, it was only during World War II that entrainers other than steam were used by the petroleum industry. Two azeotropic processes for the segregation of toluene from refinery streams were developed and placed in operation. One used methyl ethyl ketone and water as the azeo-troping agent (81) the other employed methanol (1). 

The pyrolysis experiments were conducted in an electrically heated, once-through tubular flow reactor, designed to simulate the time-temperature history experienced in commercial steam-cracking operations. Reactor effluent compositions were ascertained by gas chromatograph and mass spectrometer analyses. Material and hydrogen balances could always be effected, with typical closures of 98 2 wt %. 

The metal catalysts active for steam reforming of methane are the group VIII metals, usually nickel. Although other group VIII metals are active, they have drawbacks for example, iron rapidly oxidizes, cobalt cannot withstand the partial pressures of steam, and the precious metals (rhodium, ruthenium, platinum, and palladium) are too expensive for commercial operation. Rhodium and ruthenium are ten times more active than nickel, platinum, and palladium. However, the selectivity of platinum and palladium are better than rhodium [1]. The supports for most industrial catalysts are based on ceramic oxides or oxides stabilized by hydraulic cement. The commonly-used ceramic supports include a-alumina, magnesia, calcium-aluminate, or magnesium-alu-minate [4,8]. Supports used for low temperature reforming (< 770 K) are... 

First, let us consider in some detail the products which can be obtained via thermal cracking of liquid hydrocarbons. Table I includes all of the products known or believed to be marketed from commercial steam-cracking operations. Certainly the lower molecular weight materials are well known. Since the liquid products of cracking are less familiar, they are discussed in some detail. 

There appears to be a linear relationship between the logarithm of the rate and of the steam pressure. It must be mentioned that at the high steam pressures, water conversions were below 6%, while at the lowest steam pressure and 1740°F., a maximum of 49% of the water was consumed. Since commercial operation may use up to 75% of the water ed, extrapolating from the above data cannot be made to commercially... 

It must be noted that the above rates are conservative since they are based on only the fixed carbon content of the feedstock. In the test unit and under the procedure employed, about 7-14% of the carbon appeared in the devolatilized gas and 14-26% of the total carbon went to tar and loss. This occurred when the coal was added to the molten salt before the steam was cut in. In commercial operation with bottom feeding, the carbon in the volatile matter will be reformed in passing up the 10-20 ft. 

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