High-activity zeolite catalyst

Efficient contacting of the feed and catalyst is critical for achieving the desired cracking reactions. Steam is commonly used to atomize the feed. Smaller oil droplets increase the availability of feed at the reactive acid sites on the catalyst. With high-activity zeolite catalyst, virtually all of the cracking reactions take place in three seconds or less. 

Recently, new upflow operation (riser cracking) has become popular, through the development of highly active zeolite catalyst (V15). 

Despite the dilution, high-activity zeolite catalysts achieved almost 100% riser cracking compared with only 15-20% with silica/alumina catalysts. This made it possible to redesign FCC units with full riser cracking and so avoid the usual overcracking in the dense phase of the reactor. Increased conversion and higher throughput led to a reduction in the volume of heavy cycle oil produced and recycle rates could be decreased. Thus, production capacity was further increased with httle capital expenditure. 

Catalyst Preparation. For most of the experiments conducted in this study, nickel or vanadium impregnated non-zeolitic particles were blended with metals-free high activity cracking component. This allowed us to examine the effects of the metals on the non-zeolitic component. The high activity zeolitic particles were prepared by in-situ zeolite synthesis on kaolin-based microspheres... 

Catalysts were contaminated with nickel and vanadium according to the method of Mitchell ( ), using metal naphthenates. Prior to blending, all contaminated materials were steamed (1450 F, 4 hrs, 90% steam, 10% air) to age the metals. The selectivity effects of the metals on the non-zeolitic component were determined by blending impregnated non-zeolitic components with 20% of the steamed, uncontaminated high activity zeolitic component such that the overall blend yielded 70% conversion. 

Figure 1731. Fluidized bed reactor processes for the conversion of petroleum fractions, (a) Exxon Model IV fluid catalytic cracking (FCC) unit sketch and operating parameters. (Hetsroni, Handbook of Multiphase Systems, McGraw-Hill, New York, 1982). (b) A modem FCC unit utilizing active zeolite catalysts the reaction occurs primarily in the riser which can be as high as 45 m. (c) Fluidized bed hydroformer in which straight chain molecules are converted into branched ones in the presence of hydrogen at a pressure of 1500 atm. The process has been largely superseded by fixed bed units employing precious metal catalysts (Hetsroni, loc. cit.). (d) A fluidized bed coking process units have been built with capacities of 400-12,000 tons/day.

Conventional sulfuric acid and HF alkylation processes ( >2, ) employ liquid-liquid catalytic systems which are expensive and troublesome because of such problems as maintaining an acid/hydrocarbon emulsion, product separation and waste disposal (H2SO4 process only). A solid catalyst should eliminate many of these problems. In view of their high activity, zeolites have been used by a number of workers (4,5,6,2) cata-... 

PREPARATION OF HIGHLY ACTIVE ZEOLITE-BASED HYDRODESULFURIZATION CATALYSTS ZEOLITE-SUPPORTED Rh CATALYSTS... 

On the basis of the proposed mechanism, it can be possible to develop much more highly active zeolite-based hydrodesulfurization catalysts for petroleum feedstocks. 

Catalysts in thin-wall honeycomb form offer the advantages of low pressure drop, high geometric surface area, and short diffusion distance as compared to conventional pellets and beads in fixed bed reactors (1). Active zeolite catalysts may be extruded in the form of a honeycomb structure or they may be washcoated on ceramic honeycomb substrates. The latter technique has been widely used in automotive emissions control (2), woodstove combustors (3), control of volatile organic emissions from organic solvents (4), ozone abatement in jet aircraft passenger cabins (5), and N0x abatement... 

Numerous reports of heterogeneous catalysis active for alkylaromatic oxidations have appeared. These include an encapsulation of metal ions by zeolites or polymers [92-95]. Non-Co, Pd-based heterogeneous catalysts have been discovered by BP researchers [96-98]. Very recently, nanocrystalline ceria (Ce02) has been discovered to be a highly active heterogeneous catalyst for oxidation of pX in water to TA [99,100]. 

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