Houdry process catalysts

Acid-treated clay minerals were employed as cracking catalysts in the first commercial process, the Houdry process, widely used in the early petroleum industries to produce high-octane gasoline. The Houdry process catalysts had been discussed extensively by many investigators (2) but were eventually completely replaced by synthetic silica-alumina or zeolite catalysts. Recently, the need for new catalytic materials has revived special interest in the layer lattice silicates because of their ion-exchange properties and their expandable layer structures. 

Dehydrogenation of /i-Butane. Dehydrogenation of / -butane [106-97-8] via the Houdry process is carried out under partial vacuum, 35—75 kPa (5—11 psi), at about 535—650°C with a fixed-bed catalyst. The catalyst consists of aluminum oxide and chromium oxide as the principal components. The reaction is endothermic and the cycle life of the catalyst is about 10 minutes because of coke buildup. Several parallel reactors are needed in the plant to allow for continuous operation with catalyst regeneration. Thermodynamics limits the conversion to about 30—40% and the ultimate yield is 60—65 wt % (233). 

Catadiene [Catalytic butadiene] Also spelled Catadien. A version of the Houdry process for converting mixtures of butane isomers into butadiene by dehydrogenation over an alumina/chromia catalyst. Another version converts propane to propylene. Rapid coking of the catalyst necessitates use of several reactors in parallel, so that reactivation can be carried out continuously. Developed by Houdiy and first operated at El Segundo, CA, in 1944. By 1993, 20 plants had been built worldwide. Now licensed by ABB Lummus Crest. 

CATOFIN [CATalytic OleFIN] A version of the Houdry process for converting mixtures of C3 - C5 saturated hydrocarbons into olefins by catalytic dehydrogenation. The catalyst is chromia on alumina in a fixed bed. Developed by Air Products Chemicals owned by United Catalysts, which makes the catalyst, and licensed through ABB Lummus Crest. Nineteen plants were operating worldwide in 1991. In 1994, seven units were used for converting isobutane to isobutylene for making methyl /-butyl ether for use as a gasoline additive. 

Cycloversion A petroleum treatment process which combined catalytic reforming with hydrodesulfurization. The catalyst was bauxite. The process differed from the Houdry process in that the catalyst bed temperature was controlled by injecting an inert gas. Developed by the Phillips Petroleum Company and used in the United States in the 1940s. Pet. Refin., 1960, 39(9), 205. 

Houdry The first catalytic petroleum cracking process, based on an invention by E. J. Houdiy in 1927, which was developed and commercialized by the Houdry Process Corporation. The process was piloted by the Vacuum Oil Company, Paulsboro, NJ, in the early 1930s. The catalyst was contained in a fixed bed. The first successful catalyst was an aluminosilicate mineral. Subsequently, other related catalysts were developed by Houdry in the United States, by I. G. Farbenindustrie in Germany, and by Imperial Chemical Industries in England. After World War II, the clay-based catalysts were replaced by a variety of synthetic catalysts, many based on alumino-silicates. Later, these too were replaced by zeolites. U.S. Patents 1,837,963 1,957,648 1,957,649. 

The inherent variability of the raw mineral, particularly with respect to minor constituents which in certain cases were known to have major effects on the cracking reaction, led to the development by the Houdry Process Corp. of a synthetic silica-alumina catalyst of controlled chemical composition and more stable catalytic properties. Full scale manufacture of synthetic catalyst was started in 1939. 

Dehydrogenation of z7-butane via the Houdry process is carried out under partial vacuum (35-75 kPa) at about 535-650°C with a fixed-bed catalyst. The catalyst contains... 

DETOL [DE-alkylation of TOLuene] A process for making benzene by de-alkylating toluene and other aromatic hydrocarbons. Developed by the Houdry Process and Chemical Company, and generally similar to its Litol process for the same purpose. The catalyst is chromia on alumina. Licensed by ABB Lummus Global. Twelve plants, had been licensed in 1987. 

Houdriforming A continuous catalytic reforming process for producing aromatic concentrates and high-octane gasoline. It used a fixed bed of a platinum catalyst. Developed in the 1950s by the Houdry Process Corporation. 

Litol Also called Houdry-Litol. A process for making benzene by dealkylating other aromatic hydrocarbons. This complex process achieves desulfurization, removal of paraffins and naphthenes, and saturation of unsaturated compounds, in addition to dealkylation. The catalyst contains cobalt and molybdenum. Developed by the Houdry Process and Chemical Company and Bethlehem Steel Corporation. First installed by the Bethlehem Steel Corporation in 1964. Subsequently used at British Steel s benzole refinery, Teesside, England. 

The first successful catalytic cracking process was the Houdry process, announced in 1933 (132) and commercialized in 1936 (172). This was a fixed-bed process employing, at first, an activated bentonite clay as catalyst. It had been known previously that certain types of decolorizing clays catalyzed the decomposition of hydrocarbon oils (165,188), but a carbonaceous deposit rapidly accumulated on the clay and seriously impaired its activity. During his early work in France, between 1927 and 1930, Houdry found that catalyst activity could be maintained at a satisfactory level by carefully burning off the carbonaceous deposit, or coke, at frequent intervals before the concentration became high enough to interfere seriously with the desired catalytic reactions. 

Heat is removed from the regenerator by means of the circulating catalyst, supplemented by water-cooled tubes. This technique eliminates the need for the complex and expensive temperature-control system used in the Houdry process (the closely spaced, perforated inlet and outlet pipes, and the circulating molten-salt system). 

In 1940, Houdry Process Corporation initiated commercial manufacture of a synthetic silica-alumina catalyst at Paulsboro, New Jersey (133). The synthetic catalyst is produced in pellet form (51,265) and contains 12 to 13% alumina (221,276). It has the advantages of controlled chemical composition, higher purity, and greater heat stability, but is more expensive than the activated-clay catalyst. 

Entrained catalyst is removed from the product off-gas by means of cyclones. The catalyst circulates continuously from the reactor to the regenerator and vice versa by means of transfer lines. Coke deposited on the catalyst is burnt off in the regenerator however, because the amount of coke is relatively small, additional fuel must be burnt in the regenerator to satisfy the thermal requirements of the endothermic dehydrogenation reaction. However, while this approach is similar to that in the Houdry process, FED does not have a catalyst reduction step with hydrogen before proceeding to the dehydrogenation cycle lack of this step is believed to be somewhat detrimental to the overall performance of the process. 

While natural or activated clay catalysts are no longer employed in the fixed-bed Houdry process, they are still widely used in the fluid process and to a considerable extent in the TCC process. A natural bauxite catalyst is employed in the fixed-bed cycloversion process, developed by the Phillips Petroleum Company. This process is of greater importance as a naphtha reforming process than as a catalytic cracking process. 

The catalyst, 20% chromia (Cr203) on alumina, is manufactured by the Houdry Process Corp. and is designated as Type A50. Typical properties are ... 

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