PTQ Q1 2026 Issue

Due to the variability of the feed type to the unit, the period from June 15, 2023 to June 31, 2023 is evaluated by using a thermodynamic simulator, calibrated for the condi- tions of the test run after the technological modifications carried out between December 11, 2024 and December 13, 2024. The effective performances for the June 2023 period are then compared with the simulated perfor- mances considering the technology upgrade. u Calibration of the thermodynamic model with test run data: Using the proprietary Hysys thermodynamic simulator and in-house modelling from Axens (resulting in similar tendencies), the model was calibrated with the feed, operating conditions, and product data from the test run periods. These included the low conversion period at the design feed flow rate and the lowest operative reaction temperature, as well as the high conversion period at the design feed flow rate, which was constrained by the max - imum reaction temperature allowable under separation system limitations. Both the low and high conversion periods calibrate with a good parameter adjustment, allowing modelling in condi- tions of low and high conversion. The results of the model are presented in Table 7 .  Simulation of the 2023 period with technologi- cal modifications and evaluation : Considering that the period to be evaluated is one of low conversion, the Hysys simulator is used to apply calibration factors during this period. With the feed data and average operating condi- tions for the period from June 15, 2023 to June 31, 2023, the resulting unit products and conditions in the regen - erators are then compared in order to assess the impact of the technology upgrade. Table 8 shows the evaluation results. Based on Table 8 results, the main conclusions are as follows: u 5% increase in unit conversion, mainly by converting LCO to gasoline.  An increase in the coke produced, mainly due to a reduction in its hydrogen content.  A reduction in the dry gas produced.  An increase in the cat/oil ratio.  A reduction in the delta coke, allowing a higher percent- age of residual feed to be incorporated. Evaluation of new unit operating constraints During the high conversion period test run, the unit is maintained at the highest reaction temperature permissi- ble within the limitations of the separation section. It is found that the restriction in these conditions is con- centrated in the light ends recovery unit stripper, debu- taniser and depropaniser sections. Table 9 represents their use. It should be noted that the depropaniser tower is designed to operate at 105% of its base capacity. The debutaniser tower exceeds the design utilisation during the high conversion test. For its part, the main air blower operated at 95% of its maximum air capacity, with peaks of up to 97%. The wet gas compressor averaged 96% of its nominal capacity during the test and reached peaks of 100%. This

Light ends recovery section utilisation by unit

Unit

Utilisation (%)

Stripper

Debutaniser Depropaniser

102

1 Utilisation is defined as: (Products + Reflux)/(Products design + Reflux design).

Table 9

resulted in gasoline capacity limits being exceeded, over- loading the absorption system. Conclusions The technological modifications completed during the turn - around aimed to achieve two objectives: improvement in the unit’s performance (Scope A) and reduction of particu- late matter emissions (Scope B). Considering the results presented, an improvement in unit conversion, a reduction in dry gas, and increased LPG and gasoline yields are confirmed, as evaluated in a feed processed during a period in 2023. In addition, a reduction in particulate matter emissions is achieved in the range of 45% to 65% compared with the emissions of the period 2022-2023.

RS2, Sweetn’K, Sulfrex, and G-Series are marks of Axens. HYSYS is a mark of AspenTech.

This article is based on a presentation from the Axens/Technip Energies 15th FCC Forum in Prague, Czech Republic (12-15 May, 2025).

Further reading 1 ANCAP: www.ancap.com.uy/1581/1/historia-de-la-refineria.html 2 Axens: www.axens.net/solutions/advanced-process -licensing-solutions Francy Barrios is Lead Technology Engineer for FCC and sweeten- ing technologies at Axens. With 17 years of experience in the refining industry, specifically in FCC processes, her main responsibilities are the preparation of technical proposals for grassroots units and revamp projects for FCC and sweetening units (like the proprietary Sulfrex and proprietary Sweetn’K for LPG and kerosene), supervising FCC cata- lysts evaluation, and providing clients technical support. Barrios is a chemical engineer graduating from the Universidad de Los Andes of Venezuela. Email: francy.barrios@axensgroup.com Marcel Sabag is a refining professional at ANCAP’s La Teja Refinery in Montevideo, Uruguay, where he has actively contributed to key initiatives, including the technological revamp of the FCC unit, devel- opment of dynamic simulation models, and implementation of per- formance indicators and safety analyses. His work spans technical leadership in catalyst handling, instrumentation upgrades, and pro- cess troubleshooting. Sabag has presented at LARTC and FCC Forum meetings and was nominated for the ‘Outstanding Engineer’ award in 2024. He is a chemical engineer with a specialisation in process engineering. Email: msabag@ancap.com.uy

PTQ Q1 2026