Catalytic cracking catalyst evaluation

D-3907 Method for Testing Fluid Catalytic Cracking Catalysts by Microactivity Test Activity of FCC catalysts as evaluated by percent conversion of gas oil using a fixed bed reactor... 

Evaluation of Coke Selectivity of Fluid Catalytic Cracking Catalysts... 

Development of a Test Procedure To Evaluate Fluid Catalytic Cracking Catalyst... 

Mitchell, M.M. and Moore, H.F., "Protocol Development For Evaluation of Commercial Catalytic Cracking Catalysts", Paper Presented at the Symposium on Preparation and Characterization of Catalysts before the Division of Petroleum Chemistry, Inc., American Chemical Society Meeting, Los Angeles, September 25-30 (1988). 

When deactivation occurs rapidly (in a few seconds during catalytic cracking, for instance), the fresh activity can be found with a transport reac tor through which both reac tants and fresh catalyst flow without slip and with short contact time. Since catalysts often are sensitive to traces of impurities, the time-deac tivation of the catalyst usually can be evaluated only with commercial feedstock, preferably in a pilot plant. 

Performance Analysis. In order to determine the effect of hydrotreating on catalytic cracking performance, the above feedstocks were evaluated at a low severity cracking condition (catalyst-to-oil ratio of 6.0 and reactor temperature of 910° F) and a high severity cracking condition (catalyst-to-oil of 8.0 and reactor temperature of 1010° F). The results from the catalytic cracking of these feedstocks (shown in Tables I and II) are shown in Tables III through V. The results presented in these tables are... 

P. O Connor, A.C. Pouwels and J.R. Wilcox "Evaluation of Resid FCC Catalysts" Symposium on Catalytic Cracking of Heavy Oils, paper 242E,... 

A great need exists for reliable Fluid Catalytic Cracking performance tests which can be used for the evaluation of feedstocks and catalysts. 

Catalytic Cracking Test. A standard microactivity test (MAT) was used to evaluate the conversion and selectivity of catalyst samples. The tests were done at the University of Pittsburgh s Applied Research Center (former Gulf Research Laboratory), a qualified laboratory for MAT evaluations. A standard method, developed by Gulf, was used without modification. A Cincinnati gas oil was cracked under the following conditions cat/oil=3, 16 h 1 WHSV, and 516°C. Prior to charging the reactor, all samples underwent a standard thermal pretreatment. Solids were first heat shocked for 1 h at 593°C. Next, selected materials were impregnated with 3000 ppm Ni and 6000 ppm V, as naphthenates. Then all samples were calcined for 10 h at 538°C. Finally, each material was steamed at 732°C for 14 h in a fluidized bed to produce a catalyst in a simulated equilibrium state. 

Overall, evaluation of catalysts on resid feedstocks requires sophisticated and well integrated catalyst deactivation, catalyst stripping and cracking systems. It is important to determine not only the coke yield, but each of its components (Catalytic coke, contaminant coke, CCR coke and stripper (soft) coke). This paper provides details on how each of the components of the coke yield may be experimentally determined using catalyst metallation by cyclic deactivation, catalyst strippability measurements and modified catalytic cracking techniques. 

The most widely used conventional chemical methods are pyrolysis [21-25] and catalytic cracking [13, 26-30], The latter yields products with a smaller range of carbon numbers and of a higher quality than products generated by the former method. Several types of solid acid catalysts, which are known to be effective for catalytic cracking (e.g. HZSM-5, HY and rare earth metal-exchanged Y-type (REY) zeolite and silica-alumina (SA)) were evaluated by catalyst screening tests and are listed in Table 6.1. The acidic... 

The use of CeOs-based materials in catalysis has attracted considerable attention in recent years, particularly in applications like environmental catalysis, where ceria has shown great potential. This book critically reviews the most recent advances in the field, with the focus on both fundamental and applied issues. The first few chapters cover structural and chemical properties of ceria and related materials, i.e. phase stability, reduction behaviour, synthesis, interaction with probe molecules (CO. O2, NO), and metal-support interaction — all presented from the viewpoint of catalytic applications. The use of computational techniques and ceria surfaces and films for model catalytic studies are also reviewed. The second part of the book provides a critical evaluation of the role of ceria in the most important catalytic processes three-way catalysis, catalytic wet oxidation and fluid catalytic cracking. Other topics include oxidation-combustion catalysts, electrocatalysis and the use of cerium catalysts/additives in diesel soot abatement technology. 

Fluid Catalytic Cracking (FCC) is one of the most important process in oil refining. The evaluation of the catalysts in the laboratory scale is often carried out in a micro-reactor, the so called micro-activity test [1-3] (MAT). Coke formation plays an important role in the deactivation of FCC catalysts, which can be deactivated either permanently (loss of surface area, zeolite collapse, metals) or temporarily deactivated (coke). 

Refinery ethylene is usually made by the catalytic cracking of ethane, propane, or a mixed hydrocarbon stream, such as recovered natural gas liquids, naphthas, or gas oil [11]. Cracking conditions are quite severe 750-900°C and 0.1-0.6 second residence time for a low partial pressure hydrocarbon stream. A number of metal oxide catalysts have recently been evaluated for this purpose [12]. The usual diluent is steam, used at a weight ratio of steam to hydrocarbon of 0.2 1 for ethane feed, to progressively higher ratios with the higher molecular weight hydrocarbons of up to 2.0 1 for gas oil. 

An easy method to estimate rate constants in complex kinetic models is proposed. This method reduces the number of parameters to be estimated simultaneously. A 5-lump kinetic model for the catalytic cracking process was selected in order to tqiply the proposed methodology. Experimental data obtained in a MAT using three gas oils and a commorcial equilibrium catalyst unit were used to evaluate the rate constants. 

A MAT reactor was used to crack three industrial feedstocks over a commercial equilibrium catalyst in the range of reaction temperature of 480-500°C and WHSV of 6-48 h. The experimental data were utilized to evaluate the kinetic parameters of a 5-lump model for catalytic cracking process, which includes the unconverted gas oil, gasoline, LPG, dry gas and coke. 

It is hard to find out the most appropriate equipment/method and performance index to measure and assess the quality of catalysts, which is difficult in unified definition and standardization of methods. So far, some methods for evaluating the activities of a few catalysts such as those for catalytic ammonia synthesis and catalytic cracking have been standardized. The evaluation methods are different due to the varieties of catalysts and the experiences of researchers. Sometimes, the technical details of evaluation methods are a part of patent, such as formula and preparation process is confidential. Even then, some basic conceptions and methods for the evaluation and testing of catalysts are still worthy being introduced, which is the main focus of this chapter. 

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