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Faster lead time for emergency catalyst delivery

An incident caused irreversible poisoning of a catalyst bed in a hydroprocessing unit. The incentive for immediate catalyst replacement was $400,000 per month, and the quoted lead time was unacceptably long.  The refiner used our network to identify two feasible alternatives for faster delivery.  The outcome was 2 months faster lead time and $800,000 margin saved.

Improved refinery lab accuracy:  Refinery lab analyses of FCC gasoline and reformate were incorrectly identifying aromatic compounds as isoparaffins and naphthenes, leading to errors over 50% in PIONA data, and causing incorrect diagnoses of unit performance.  Comparison of lab data with our large database of gasoline stream analyses enabled the refinery lab to correct the identification of the aromatic peaks and is now providing accurate and precise analyses of light oils streams.

Gasoline sulfur reduction by adjustment of splitter: Detailed hydrocarbon and sulfur speciation analyses showed carryover of thiophenic sulfur into the posttreater splitter overhead.  The refinery started using these analyses to guide adjustment of splitter operation to reduce gasoline sulfur with minimal octane loss.  The refinery is now investing in new lab equipment to enable doing this routinely.

Improved planning for Tier 3 sulfur strategy:  Phone conferences with market sources enabled this client to get up-to-date data on Tier 3 sulfur credit prices which led them to develop a better Tier 3 gasoline strategy. 

Incumbent supplier blowback from purchase of Independent Catalyst Test Report:  When this refiner purchased our Independent Catalyst Test Report, the entrenched incumbent catalyst supplier, preferring no competition, went complaining to the refiners’ upper management with legalistic objections citing our failure to provide a “chain of custody” for our test samples.  When we asked the supplier to explain their complaints and show an example of what a “catalyst sample chain of custody” looks like, there was no reply.  We know this supplier never requires a chain of custody for pilot plant test samples.  Such objections are totally bogus.

Revamped VGO hydrotreater fails in mild hydrocracking service:  A major licensor expanded this FCC pretreat unit, using a new high activity pretreat catalyst and adding a partial load of hydrocracking catalyst to enable mild hydrocracking. On startup, the actual feed was much more difficult than the design basis. The first cycle was 10 months versus 36 months expected, and the unit ran all 10 months as an FCC pretreater with no hydrocracking activity. The licensor did not identify the root cause which was high nitrogen and heavy polynuclear aromatics (HPNA) in the feed. The pretreat catalyst was unable to complete its job, meaning the hydrocracking catalyst was poisoned from day 1 by nitrogen and HPNAs.  The second cycle used a different catalyst supplier with regular feed monitoring and feed management.

Cycle life estimates for diesel reload vary from 7 to 44 months: Recent cycles on this low-pressure unit used stacked beds of 3 catalysts, 2 different CoMo’s and one NiMo.  The request for reload proposal requested quotes for the suppliers’ highest activity CoMo for the reload.  Cycle life estimates from the suppliers varied from 7 months to 44 months, demonstrating a point we make to our clients:  It is virtually impossible to predict cycle life.  Better to select catalysts based on comparison of initial activity in a pilot plant test done on catalysts that are known to have normal stability.

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Hoekstra war stories

In the past two years, there have been many field failures in ultra-low sulfur diesel (ulsd) hydrotreaters. By field failures we mean short cycles of less than half the expected cycle life. The root cause of these failures was overestimating what a catalyst can do in a hydrogen starved unit.


Cycle life estimates for catalyst reload vary from 7 to 44 months

It is very difficult to accurately predict the cycle life for a hydroprocessing unit. This is especially true with today’s highly variable feed slates. Despite this fact, catalyst suppliers are always asked to estimate cycle life when bidding for a catalyst reload, and they comply with the request ...


High aromatic/nitrogen feeds cause rapid initial deactivation in pilot plants

A feed sent to C Solutions in Thessaloniki, Greece caused catalyst to deactivate very rapidly when introduced on day one of a pilot plant run.  Analysis showed the feed to be full of high boiling aromatics and high in nitrogen. The pilot plant run was restarted with the usual 3-day break-in ...


Hydrogen-starved unit struggles to make ULSD

This is a 36 bar (525 psig) unit that was converted to ulsd service. The first two cycles used Albemarle KF-757 and lasted 6 months compared to one year expected cycle life. They switched to Topsoe catalyst for the next cycle and saw no improvement.

Two suppliers recommended replacing ...


Refinery weighs proposals for 10 ppm diesel

This refinery wanted to make 10 ppm diesel in blocked out commercial trials as preparation for upcoming diesel specifications. Some catalyst vendors said the refinery would need to double the reactor volume to make 10ppm. Other vendors said they had a new drop-in solution, a catalyst that will do the ...


Sulfur speciation analysis helps with feedstock management

Cycle life for successive runs on this diesel hydrotreater has varied from 6 to 18 months.The cycle history was analyzed to assess the difficulty of processing varying feeds. Sulfur speciation analysis enabled measurement of difficult sulfur in the feed components. The unit’s cycle life was found ...


Faster lead time for emergency catalyst delivery

An incident caused irreversible poisoning of a catalyst bed in a hydroprocessing unit. The incentive for immediate catalyst replacement was $400,000 per month, and the quoted lead time was unacceptably long.  The refiner used our network to identify two feasible alternatives for faster delivery.  ...