ASTM D5154 Standard Test Method for Determining Activity and Selectivity of Fluid Catalytic Cracking (FCC) Catalysts by Microactivity Test

Get Certified ASTM D5154 Testing for Reliable FCC Catalyst Performance

A single FCC inventory represents months of production and significant capital expenditures. Before the catalyst reaches the riser, the laboratory reveals activity and yield variations. Moreover, accredited laboratories run the procedure on calibrated micro-activity units against reference catalysts in recognized laboratories, maintaining the comparability of supplier data. Then, refiners use defensible numbers rather than vendor assertions for benchmarking, negotiating,  and troubleshooting.

• Calculates the mass percentage conversion of gas oil feed to determine catalyst activity.
• Calculates selectivity using mass percent yields of specific cracked products.
• Concerns equilibrium and FCC catalysts that have been deactivated in the lab
• Establishes the standard reaction temperature at 516 °C [960 °F].
• Describes the product collection system of the microactivity unit.
• Describes the examination of the coke, liquid, and gaseous products.
• Reports values individually in either SI or inch-pound units.

What are the Uses of ASTM D5154 Testing?

Refiners can learn how a catalyst will crack their own feedstock before making a purchase by using this kind of testing. In turn, catalyst developers establish a direct connection between measured yield shifts and formulation modifications. This standard-

• Assigns a common, repeatable ranking to rival FCC catalysts.
• Screens new compositions during catalyst research and development.
• Monitors the equilibrium catalyst’s activity loss during a run.
• Measures the selectivity of gasoline, LPG, dry gas, and coke.
• Encourages research on feedstock and catalyst matching.
• Directs supplier qualifying and purchasing decisions.
• Provides yield estimations for FCC units and kinetic models.

Which materials can be tested under ASTM D5154?

ASTM D5154 applies to catalytic cracking catalysts that are in powder form. These can be either equilibrium catalysts or laboratory-deactivated ones. If the catalyst is fresh, technicians must steam-deactivate it first. Technicians usually perform this step according to Guide D4463. This step is necessary because an unaged sample can give a higher activity reading than expected. Laboratories also test catalyst blends and systems that include additives. They only perform this testing when the sample reflects the inventory in the unit. Before testing begins, the analyst makes sure to confirm the catalyst history. They also check the gas-oil feed properties and the target catalyst-to-oil ratio.

Why is ASTM D5154 Important?

Conversion, gasoline yield, and coke yield all affect how profitable an FCC unit is. A catalyst that does a job of converting but leaves too much coke can cause problems in the regenerator and limit how much can be processed. This test method looks at conversion and each product’s yield separately. Because of that, refiners choose a catalyst that has the balance of yields instead of just picking the one with the highest conversion.

ASTM D5154 Testing Process and Data Collection

The analyst begins by choosing a catalyst sample that represents the batch and a gas oil feed with known characteristics. Technicians then weigh the charged catalyst into the reactor and heat the bed to the desired temperature. Once the system is ready, they start feeding the gas oil at a rate. During this phase, the unit records temperature readings, injection times, and nitrogen flow rates. After the run, operators flush the bed to remove any remaining materials, collect the gas products, and regenerate the catalyst to measure coke formation. Laboratories then analyze each product fraction, check the mass balance, and determine conversion levels and yield percentages. 

Common Challenges and Troubleshooting

Dependable results depend on a mass balance, which laboratories check after every single run. When the mass balance is not tight, the problem often comes from leaks, warm or cold traps, or incomplete stripping of the spent bed. Temperature drift across the catalyst bed can also change selectivity because catalytic cracking is strongly endothermic. Technicians therefore check placement, calibrate the feed pump, and confirm gas volume measurement before each series. Running a reference catalyst beside the sample helps to expose any drift in the unit.

• The laboratory reports conversion, gasoline, cycle oil, bottoms, dry gas, LPG, and coke yields as mass percentages (%), while the analyst calculates catalyst activity from the measured conversion.
• The analyst evaluates catalyst activity and selectivity by comparing conversion and product yields at the specified catalyst-to-oil ratio and, for selectivity comparisons, at the same conversion level.
• The laboratory performs the test at the specified temperature of 516 °C (960 °F) and considers results obtained at other temperatures separately because they may not directly match results from the standard test temperature.
• The laboratory checks the mass balance of the test results and repeats the test when the calculated mass balance falls outside the permitted range.

Link to ASTM D5154