of cogenerated steam for nominal steam production. The refinery of the future would have a swing boiler with full standalone cold restart capability to maximise coproduc- tion potential for the refinery and the grid. The digital trans - formation allows real-time integration between the refinery and the electricity producer. Energy efficiency equals lower greenhouse gas emissions. Q What optimal mass transfer/product separation con - figurations benefit the integration of catalytic reforming and aromatics complexes? A Sidhartha Aggarwal, Offering Management, Business Development, Refining Technologies & Catalysts, sidhar- tha.aggarwal@honeywell.com; Sharad Yadhav, Senior Offering Manager/Portfolio Manager – Petrochemicals, BTX, Honeywell UOP, sharad.yadhav@honeywell.com, Honeywell UOP Molecule management, particularly molecular precision, is one of the most critical aspects in optimising integrated catalytic reforming and aromatic complexes. The process begins with optimised separation in the naphtha splitter column. This ensures that all aromatic-generating mol - ecules, preferably rich in C 6 to C 8 hydrocarbons, are routed into the heavy naphtha stream while minimising lighter or non-naphthenic paraffins to reduce catalytic cracking and the resultant, lower-valued byproducts in the downstream complex. UOP’s proprietary CCR Platforming process employs specialised catalysts to maximise the conversion of heavy naphtha into aromatics. The main product from the Platforming unit is reformate, which is rich in aromatics components. In addition, byproducts such as fuel gas and co-products such as hydrogen and LPG are generated in the Platforming unit, which may have different applications depending upon the refinery configuration and needs. The reformate is further fractionated in the Platforming unit using debutaniser and/or depentaniser columns to remove low-value lighter hydrocarbons (C5 and lighter), simplify - ing downstream processing and lowering installation and maintenance costs. The C 7 - fraction from the reformate splitter proceeds to the proprietary UOP Extractive Distillation (ED) Sulfolane process, which utilises tetrahydrothiophene 1,1-dioxide (Sulfolane) as a solvent. This method effectively recovers high-purity benzene and toluene from hydrocarbon feeds, requiring less than 80% of the capital investment compared to traditional liquid-liquid extraction. Incorporating a proprietary Tatoray unit into an aromat - ics complex can significantly boost the yield of PX from naphtha. By feeding A9 and A10 byproducts with toluene into the Tatoray unit, additional methyl groups shift the chemical equilibrium from benzene production to xylenes, facilitating the production of mixed xylenes from low-value toluene and heavy aromatics. The proprietary UOP PX-Plus process selectively dis - proportionates toluene to produce benzene and xylenes, achieving a paraxylene concentration of about 90%, con - siderably higher than the 25% equilibrium achievable
through transalkylation technologies like Tatoray. The proprietary Parex process uses adsorptive separation to recover paraxylene from mixed xylenes, notably employing a solid zeolitic adsorbent (ADS-50) in a continuous format that simulates counter-current flow. The benzene-toluene fractionation (BTF) unit, featuring a dividing wall column (DWC) design, separates benzene, toluene, and xylenes in a single vessel, optimising plot size and reducing both capital and energy costs while enhanc - ing product purity. Finally, the xylenes fractionation unit is crucial for recovering xylene feed for the Parex process and light aromatics for Sulfolane. This unit includes multiple columns and is highly integrated with other plant sections for energy efficiency, utilising MD trays and proprietary High Flux tubes to maximise utilities and reduce capital investments. Q What new FCC stripper technologies are available that can deliver higher efficiency and optimised heat and pressure balance? A Rohit Agrawal, Project Development Manager, Honeywell UOP, rohit.agrawal@honeywell.com Today’s fluidised catalytic cracking (FCC) units have adopted reactor riser technologies that increase catalyst circulation rates and improve yields. As a result, the spent catalyst stripper often operates above the original catalyst flux design value, which can compromise hydrocarbon dis - placement efficiency and overall unit performance. UOP developed Advanced Fluidization (AF) spent cata - lyst packed stripping technology to improve both FCC unit yield performance and catalyst circulation (hydraulic) per- formance. UOP’s AF Packing incorporates recent advance - ments in stripper internal technology, consisting primarily of a bed of structured packing, and is the standard offer - ing for new and revamped units. AF Packing eliminates the rigid baffle design and the associated conical rolled plate construction. From a maintenance perspective, this option requires significantly less welding and post-weld heat treatment compared to baffle-type stripper technol - ogy. Additionally, structured packing is resistant to ero - sion, allowing UOP to expect the AF Packing to operate for at least two four to five-year operating campaigns, with commercial experience supporting even longer expected run lengths. AF Packing leads to significant benefits with improved yields and hydraulic performance: • Lowers delta coke operation and consequently reduces regenerator temperature. • Increases catalyst circulation (cat/oil ratio), leading to increased conversion. • Decreases dry gas yields, enhancing product selectivity to gasoline and liquefied petroleum gas (LPG). • Improves catalyst flux. • Reduces steam consumption, thus lowering cyclone velocity and main column traffic. • Enhances mechanical reliability, reducing turnaround time. More than 30 operating units have installed AF Packing for higher conversion and reduced steam consumption.
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PTQ Q2 2025
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