Catalyst Technologies

Benzene-Based Catalyst Technology. The catalyst used for the conversion of ben2ene to maleic anhydride consists of supported vanadium oxide [11099-11-9]. The support is an inert oxide such as kieselguhr, alumina [1344-28-17, or sUica, and is of low surface area (142). Supports with higher surface area adversely affect conversion of benzene to maleic anhydride. The conversion of benzene to maleic anhydride is a less complex oxidation than the conversion of butane, so higher catalyst selectivities are obtained. The vanadium oxide on the surface of the support is often modified with molybdenum oxides. There is approximately 70% vanadium oxide and 30% molybdenum oxide [11098-99-0] in the active phase for these fixed-bed catalysts (143). The molybdenum oxide is thought to form either a soUd solution or compound oxide with the vanadium oxide and result in a more active catalyst (142). 

Third-generation high yield supported catalysts are also used in processes in which Hquid monomer is polymerized in continuous stirred tank reactors. The Hypol process (Mitsui Petrochemical), utilizes the same supported catalyst technology as the Spheripol process (133). Rexene has converted the hquid monomer process to the newer high yield catalysts. Shell uses its high yield (SHAC) catalysts to produce homopolymers and random copolymers in the Lippshac process (130). 

PGM catalyst technology can also be appHed to the control of emissions from stationary internal combustion engines and gas turbines. Catalysts have been designed to treat carbon monoxide, unbumed hydrocarbons, and nitrogen oxides in the exhaust, which arise as a result of incomplete combustion. To reduce or prevent the formation of NO in the first place, catalytic combustion technology based on platinum or palladium has been developed, which is particularly suitable for appHcation in gas turbines. Environmental legislation enacted in many parts of the world has promoted, and is expected to continue to promote, the use of PGMs in these appHcations. 

J. H. Carstensen and P. S. Pedersen, "New Developments in HTS Catalyst Technology Solve the Fischer Tropsch Problem," AIChE Ammonia Safety Symposium, San Francisco, Calif., Nov. 1989, American Institute of Chemical Engineers, New York, 1990. 

K. H. Heilman, G. K. Piotrowski, and R. M. Schaefer, Start Catalyst Systems Employing Heated Catalyst Technology for Control of Emissions from Methanol-Fueled Vehicles, SAE 93082, Society of Automotive Engineers, Warrendale, Pa., 1993. 

Historically, the destmction efficiency for chlorinated hydrocarbons is quite low. In addition, tests conducted after the chlorinated hydrocarbon is treated show that the catalyst is partially deactivated. More recent advancements in catalyst technology have resulted in the development of a number of catalysts and catalytic systems capable of handling most chlorinated hydrocarbons under a variety of conditions (19). 

B. K. SperoneUo, J. M. Chen, and R. M. Heck "Family of Versatile Catalyst Technologies for NO and CO Removal in Co-Generation," paper... 

Since the last edition several new materials have been aimounced. Many of these are based on metallocene catalyst technology. Besides the more obvious materials such as metallocene-catalysed polyethylene and polypropylene these also include syndiotactic polystyrenes, ethylene-styrene copolymers and cycloolefin polymers. Developments also continue with condensation polymers with several new polyester-type materials of interest for bottle-blowing and/or degradable plastics. New phenolic-type resins have also been announced. As with previous editions I have tried to explain the properties of these new materials in terms of their structure and morphology involving the principles laid down in the earlier chapters. 

Nitric acid is one of the three major acids of the modem chemical industiy and has been known as a corrosive solvent for metals since alchemical times in the thirteenth centuiy. " " It is now invariably made by the catalytic oxidation of ammonia under conditions which promote the formation of NO rather than the thermodynamically more favoured products N2 or N2O (p. 423). The NO is then further oxidized to NO2 and the gases absorbed in water to yield a concentrated aqueous solution of the acid. The vast scale of production requires the optimization of all the reaction conditions and present-day operations are based on the intricate interaction of fundamental thermodynamics, modem catalyst technology, advanced reactor design, and chemical engineering aspects of process control (see Panel). Production in the USA alone now exceeds 7 million tonnes annually, of which the greater part is used to produce nitrates for fertilizers, explosives and other purposes (see Panel). 

Engelhard s in-situ FCC catalyst technology is mainly based on growing zeolite within the kaolin-based particles as shown in Figure 3-9A. The aqueous solution of various kaolins is spray dried to form micR)spheres. The microspheres are hardened in a high-temperature l,3f)(TF/704°C) calcination process. The NaY zeolite is produced by digestion of the microspheres, which contain metakaolin, and mullite with caustic or sodium silicate. Simultaneously, an active matrix is formed with the microspheres. The crystallized microspheres are filtered and washed prior to ion exchange and any final treatment. 

Tamborski, G. A., Magnabosco, L. M., Powell, J. W., and Yoo, J. S., Catalyst Technology Improvements Make SO, Emissions Control Affordable, presented at Katalistiks 6th Annual FCC Symposium, Munich, Germany, May 22-23, 1985. 

Although heaters, deaerators, and chemicals are traditionally used for 02 removal, new membrane and carbon catalyst technologies have evolved and are discussed in this chapter. 

Previously, we performed single- and multi-response optimization works in order to address optimal catalyst composition (%CaO and %MnO) and optimal operating conditions (temperature and CO2/CH4 feed ratio [3]. The maximum C2 selectivity and yield of 76.6% and 3.7%, respectively were achieved in multi-responses optimization over the 12.8% CaO-6.4% Mn0/Ce02 catalyst corresponding to the optimum reactor temperature being 1127 K and CO2/CH4 ratio being 2 [3]. The recent contribution on the catalyst technology of CO2 OCM was... 

There is a real opportunity to reduce biodiesel production costs and environmental impact by applying modem catalyst technology, which will allow increased process flexibility to incorporate the use of low-cost high-FFA feedstock, and reduce water and energy requirement. Solid catalysts such as synthetic polymeric catalysts, zeolites and superacids like sulfated zirconia and niobic acid have the strong potential to replace liquid acids, eliminating separation, corrosion and environmental problems. Lotero et al. recently published a review that elaborates the importance of solid acids for biodiesel production. ... 

Reports have shown solid catalysts for esterification of FFA have one or more problems such as high cost, severe reaction conditions, slow kinetics, low or incomplete conversions, and limited lifetime. We will present research describing our newly developed polymeric catalyst technology which enables the production of biodiesel from feedstock containing high levels (> 1 wt %) of FFAs. The novel catalyst, named AmberlysH BD20, overcomes the traditional drawbacks such as limited catalyst life time, slow reaction rates, and low conversions. 

Polymers manufactured via single site catalyst technologies, because of the unique chemical catalytic environment, exhibit a more controlled molecular weight distribution and tacticity than seen with Ziegler-Natta catalyst systems. 

Lakhanpal, B. Klein, D. Leung, P., et al., Upgrading heavy oils with new catalyst technology. ePTQ, 2004. Q4. 

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