Catalytic cracking test

Microactivity Test (MAT) is a small, packed-bed catalytic cracking test that measures activity and selectivity of a feedstock-catalyst combination. 

Advances in Fluid Catalytic Cracking Testing, Characterization, and Environmental Regulations, edited by Mario L. Occelli... 

Advances in fluid catalytic cracking testing, characterization, and environmental regulations / editor, Mario L. Occelli. 

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. 

In fixed-bed catalytic cracking tests the proper decreasing delta coke response as catalyst-to-oil is increased is possible if a constant catalyst load and a constant feed injection rate are maintained. As CCR increases above 4 wt%, however, fixed-bed cracking methods are suspect because the mass balance drops significantly and the cracking performance can be measured better using other techniques (e.g.s., circulating pilot plants or fluidized-bed reactors). 

Occelli, Mario L., ed. Advances in Fluid Catalytic Cracking Testing, Characterization, and Environmental Regulations. Boca Raton, Fla. CRC Press, 2010. Series of essays concerning technological advances in this key application of fluidized bed processing. 

G. Postole, A. Auroux, in Advances, in Fluid Catalytic Cracking Testing, Characterization, arui Environmental Regulations, ed. by M.L. Occelli (CRC Press Taylor Fiancis Group, Boca Raton, 2010), pp. 199-256... 

Pressure Vessels. Refineries have many pressure vessels, e.g., hydrocracker reactors, cokers, and catalytic cracking regenerators, that operate within the creep range, i.e., above 650°F. However, the phenomenon of creep does not become an important factor until temperatures are over 800°F. Below this temperature, the design stresses are usually based on the short-time, elevated temperature, tensile test. 

The aim of this work is to compare the thermal and catalytic cracking under representative conditions. To make things easier, the zeolites are used as powder in the catalytic test. 

The first full-scale refinery test demonstration of ZSM-5 in catalytic cracking was made in the TOO unit of the Neste Oy refinery in Naantali, Finland (10). The catalyst used in this application was a composite catalyst containing both REY and ZSM-5. This commercial demonstration was a success with RON increasing up to 4 numbers. Since this initial demonstration, ZSM-5 has been used in over thirty-five units (both TOO and FCC) ranging in size from 6,000 to 90,000 barrels per day (BPD). 

Since the removal of aromatics from fuel oils lowered toxicity, attention was directed to other highly aromatic fractions. Avon weed killer, a very aromatic material, had proved toxic and it was soon proved that many other aromatic fractions were effective. Unfortunately, most of the old sources of aromatic fractions were soon exhausted, but tests proved that the bottoms from the catalytic cracked stocks were similarly toxic. Shell No. 20, Standard No. 2, and a host of other toxic weed oils soon came onto the market, and the demands on Diesel and smudge-pot oils were alleviated. 

A model for the riser reactor of commercial fluid catalytic cracking units (FCCU) and pilot plants is developed This model is for real reactors and feedstocks and for commercial FCC catalysts. It is based on hydrodynamic considerations and on the kinetics of cracking and deactivation. The microkinetic model used has five lumps with eight kinetic constants for cracking and two for the catalyst deactivation. These 10 kinetic constants have to be previously determined in laboratory tests for the feedstock-catalyst considered. The model predicts quite well the product distribution at the riser exit. It allows the study of the effect of several operational parameters and of riser revampings. 

All these characteristics make aluminium sepiolites materials worth to be tested in a larger scale for catalytic cracking of residues. 

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