January 2026
Special Focus—Sustainability and the Energy Transition
Advancing clean fuels: Jazan refinery’s gasoline optimization achievement
This article elaborates on a landmark achievement for Saudi Aramco’s clean fuel gasoline production initiative in the Jazan refinery complex. By addressing technical challenges and
leveraging innovative process adjustments, the project not only met but exceeded targets for benzene reduction and aromatics control to improve gasoline quality. This project highlights the refinery’s commitment to aligning with regional environmental standards while maximizing economic value.
Background. Saudi Aramco’s 400,000-bpd Jazan Refinery Complex (JZRC) is a full conversion oil refinery that processes Arabian crude oil. It is integrated with a 3.8-GW vacuum residue (VR) gasification power block, called the Jazan Integrated Gasification and Power Company (JIGPC), which produces hydrogen (H2), steam and other necessary utilities like nitrogen, oxygen, etc., to sustain refinery operations. This configuration is detailed in FIG. 1.
FIG. 1. The JZRC’s general flow integration.
The refinery has multiple hydroprocessing and conversion units to meet Saudi Arabia’s fuel demand, as well as export petrochemical building blocks of benzene and paraxylene. Naphtha hydrotreating (NHT), heavy naphtha reforming and continuous catalyst regeneration (CCR) units are part of the refinery’s gasoline block, providing feed to the aromatics area, including the paraxylene complex (PXC) and benzene extraction unit (BEU), as shown in FIG. 2.
FIG. 2. Overview of the JZRC’s units and H2 distribution.
The purpose of this naphtha and aromatics complex is to produce an aromatic-rich reformed naphtha cut called reformate. In turn, reformate is used to produce PX and benzene, along with H2-rich gas, that is consumed by the NHT unit, the diesel hydrotreater (DHT), the light naphtha isomerization (ISOM) unit and the aromatics processing units within the refinery. The feed to this operating area is comprised of sour straight-run naphtha from the crude distillation unit (CDU), cracked naphtha from the hydrocracker, as well as imported naphtha from an outside supplier.
Due to the presence of contaminants (organic nitrogen and sulfur), hydroprocessing of the reformer feed in the NHT is always necessary to meet final product quality and environmental regulations, as well as the health of the downstream catalytic processes affected by catalyst poisons—e.g., sulfur, nitrogen, and metals, among others.
The JZRC was initially designed to produce high-octane, clean-fuel gasoline for domestic consumption and generate petrochemical intermediates such as benzene and PX for export. However, design limitations in the aromatics complex—particularly in the BEU and PXC—hindered the refinery’s ability to meet evolving Saudi Clean Fuels specifications, which mandate benzene levels < 1 vol% and aromatics < 35 vol% (FIG. 3).
FIG. 3. The JZRC’s current operational constraints vs. design conditions.
These constraints necessitated a shift in operational strategy, focusing on maximizing benzene removal and reforming severity adjustment to ensure compliance.
Technical challenges/limitations in clean fuels production. The BEU, originally intended to extract benzene from CCR reformate, operated at only 20% of its intended capacity due to design limitations discovered during unit performance test runs. This resulted in benzene recycling and, with design hydraulic constraints, limited benzene removal efficiency. Concurrently, the inoperable adsorption unit in the PXC eliminated the critical benzene-toluene cut, further impeding BEU functionality at higher capacity operation.
The limitations in the aromatics complex led to a cascade of operational challenges to the existing operation of the gasoline pool, as indicated in FIG. 4:
- Benzene production fell by 3,800 bpd, with excessive light reformate re-routed to the gasoline pool.
- Mixed xylenes production decreased by 8,000 bpd due to heavy reformate dilution, elevating aromatics content to 35 vol% and rendering it non-compliant with clean fuels standards.
- Light raffinate from the BEU, containing elevated benzene levels (~10%), constrained ISOM throughput.
FIG. 4. The JZRC’s aromatic complex limitations, leading to non-compliance of clean fuels gasoline.
Innovative resolution to overcome design challenges. The JZRC team devised a multi-pronged strategy to address these challenges, using process simulations modeled with blending scenarios to identify optimal feedstock combinations, targeting the shifting of benzene precursors from the CCR unit’s feed to the ISOM unit’s feed. The proposed solution also addressed the requirement of BEU mothballing, followed by a mega revamp of the unit to rectify all operational and design issues. FIG. 5 provides a detailed overview of the unit’s operation and impact on the gasoline pool.
FIG. 5. The JZRC’s current operational constraints vs. the optimized gasoline initiative’s operation.
Challenges were resolved, with major changes involving the shifting of benzene precursors (FIG. 6):
- High benzene in the light reformate. To compensate for the absence of the benzene-toluene cut to the BEU, the NHT splitter was planned to be optimized for directing C6 hydrocarbons (benzene precursors) to the CCR feed. Post startup of the ISOM unit, NHT splitter adjustments were made that redirected benzene and 90% of the precursors to the light naphtha stream. Simulationsa confirmed benzene reduction in the reformate from 4 wt% to < 1 wt%, meeting clean fuels standards.
- BEU hydraulic constraints. Given the BEU’s inability to process light reformate effectively, the unit was preserved for mothballing, with preparations underway for a major revamp. In the interim, heavy reformate was rerouted to the PXC, which was expected to increase mixed xylene production by 12,000 bpd–17,000 bpd and eliminate throughput constraints in the ISOM unit.
- PXC adsorbent tower limitations. The inoperable Xymax unit prevented the generation of the benzene-toluene cut. Upon startup, the benzene-toluene cut would be exported via a dedicated jump-over line as a special-grade benzene product, ensuring operational continuity until the revamp of the BEU.
FIG. 6. Challenges were resolved, with major changes involving the shifting of benzene precursors.
FIG. 7 details the innovative solutions used to resolve the existing limitations in operational constraints, preventing the production of clean fuel gasoline from the Jazan refinery.
FIG. 7. Innovative solutions to optimize clean fuels gasoline production.
Test run implementation and outcomes. Considering the practical feasibility of the initiative from concept to implementation, a 3-wk test run was conducted on the units—including the NHT, the CCR unit, the ISOM unit and PX unit—to achieve clean fuel specifications in the Jazan refinery, targeting the following objectives:
- Reduce benzene in the reformate to < 1 wt%
- Increase mixed xylene production to 12,000 bpd–17,000 bpd
- Reduce benzene and aromatics in the gasoline pool to ≤ 1 vol% vol and ≤ 35 vol%, respectively
- Enhance light naphtha production to offset ISOM feed loss from the BEU’s light raffinate.
Several milestones for conducting tests have been reached, including tank inventories for test preparations to unit feed adjustments, optimizations of columns and conversion enhancements of reactors. FIG. 8 shows a portion of the test run, detailing how column tray temperature adjustments changed the benzene concentration in light and heavy naphtha and reformate products.
FIG. 8. A portion of test run data, showing how column tray temperature adjustments changed the benzene concentration in light and heavy naphtha and reformate products.
Upon successful implementation and adjustments in all units, the following are the test run’s key achievements:
- Benzene reduction: Benzene content in CCR’s reformate was successfully reduced from 4 wt% to 0.93 wt%, meeting and exceeding the clean fuels threshold.
- Mixed xylene production: Mixed xylene output is projected to increase from a baseline of 8,000 bpd to 12,000 bpd–17,000 bpd (ongoing).
- Gasoline pool compliance: Aromatics content in the gasoline pool was reduced to 38 vol%—targeting 35 vol% post-alkylate blending (ongoing).
During the test, several operational challenges were addressed:
- Low excess oxygen in the CCR heaters: This was addressed by fixing stuck burner air registers, troubleshooting forced-draft fan flow and recalibrating instrumentation.
- High ΔP in the ISOM reactor: Maintained up to 3.9 bar (max limit of 4.5 bar) at 80% throughput through flow dynamics optimization (H2-to-hydrocarbon ratio).
- Non-aromatics C9 contamination in the heavy reformate: This was addressed by adjusting CCR throughput and severity, leading to improved conversion of heavier components.
Economics and strategic impact. The project’s success has far-reaching implications. By reducing benzene and aromatics in the gasoline pool, the JZRC ensures compliance with Euro VI and other global standards, expanding market access for its products. Optimized CCR and ISOM operations lowered energy consumption, with excess oxygen levels in heaters dropping to 2 vol%–3 vol%, improving thermal efficiency. Economically, the ability to produce on-spec blended gasoline for the local market at competitive octane levels enhances the profitability of the refinery and reduces the need to import gasoline for the Kingdom’s southern region. Strategically, the refinery is positioned to adapt to evolving clean fuel mandates, reinforcing Saudi Aramco’s leadership in sustainable refining.
Takeaways. The Jazan refinery’s gasoline optimization test run exemplified the power of collaboration, innovation and data-driven decision-making and shows that operational ingenuity can overcome design limitations. By systematically addressing technical barriers, from reactor dynamics to blending logistics, the project has validated a scalable blueprint for clean fuels production. As global demand for low-benzene, high-octane gasoline grows, the JZRC’s achievements not only bolster Saudi Aramco’s operational excellence but also contribute to a cleaner energy future. The journey continues, with ongoing efforts to sustain the low benzene/aromatics contents and explore expanded markets for mixed xylenes, ensuring the refinery remains at the forefront of industrial transformation and enhances its position as a key supplier in Saudi Arabia’s energy landscape.
ACKNOWLEDGEMENTS
The authors extend their gratitude to the Jazan refinery’s management, Saudi Aramco, the Process and Control Systems Department, and the Global Optimizer team for their pioneering collaboration and visionary problem-solving in transforming inherent design constraints into a groundbreaking achievement under challenging operational conditions.
NOTES
a Conducted using Aspen HYSYS
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