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• What type of flexibility can be built into a hydrocracker to quickly shift from naphtha to diesel output?

  Feb-2025

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Answers

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• James Esteban, Unicat Catalyst Technologies, James.Esteban@unicatcatalyst.com

  In the ever-evolving landscape of hydroprocessing, the ability to adapt operations swiftly is paramount for refiners aiming to optimise production and meet market demands. A well-designed graded bed system, particularly utilising Unicat’s Advanced Filtration System (AFS) and MagAFS technologies, is essential for enhancing the operational flexibility of hydrocrackers. These systems not only optimise catalyst performance but also ensure that refiners can respond effectively to changing product requirements, such as shifting from naphtha to diesel output.

  The design of the catalyst bed is fundamental to the efficiency and longevity of hydrocracking operations. AFS technology provides a unique solution by offering high available void space and optimised flow channels, mitigating pressure drop, which is critical in maintaining consistent reactor performance. The AFS allows for uniform distribution of reactants, ensuring that the catalyst operates at peak efficiency throughout its lifecycle.

  Refineries utilising AFS have reported significant improvements in operational metrics. For instance, one facility experienced a 150% increase in cycle length compared to traditional grading systems, leading to reduced downtime and enhanced profitability. This extended cycle life translates to lower operational costs and improved throughput, allowing refiners to maximise output without compromising product quality.

  Hydrocracker flexibility
  The flexibility built into hydrocracker operations through advanced catalyst systems like AFS and MagAFS is multifaceted. The ability to quickly adjust operational parameters allows refiners to optimise yields based on real-time market conditions. When transitioning from naphtha to diesel production, the graded bed system can accommodate changes in feed composition and processing conditions without significant downtime. In one case, a refinery successfully shifted its output from naphtha to diesel within a matter of hours, thanks to the rapid response capabilities enabled by the AFS. This adaptability not only meets immediate market demands but also positions the refinery to capitalise on price fluctuations, enhancing overall profitability.

  Integration of demetalisation catalysts within the AFS framework enhances the ability to process a wider range of feedstocks. By effectively removing contaminants such as metals, these catalysts prolong the life of the primary hydrocracking catalysts and facilitate smoother transitions between different product outputs. Facilities employing Unicat’s demetalisation and grading catalysts have reported a minimum of a 30% reduction in catalyst replacement frequency, significantly lowering maintenance costs and improving operational efficiency. This reduction in downtime and/or process unit utilisation is crucial for maintaining continuous production and meeting customer demands.

  Significant demetalisation of the feed to the hydrocracker using MagAFS is seen in commercial operations on naphtha (light coal tar). This process has successfully demonstrated the removal of up to 98% total solids and 60-100% various metals in the feed steam, as shown in Table 1.

  Although vanadium is not shown in the tested liquid stream, the mass susceptibility (magnetising characteristic) of V₂O₃ (1,976 x 10-6 c.g.s. unit) is much higher than that of NiO (600 x 10-6 c.g.s. unit). Therefore, V₂O₃ is easier than NiO to be removed by MagAFS.

  In conclusion, the implementation of a well-designed graded bed system using AFS and MagAFS technologies is vital for enhancing the flexibility of hydrocracker operations. By ensuring optimal catalyst performance and facilitating quick adjustments in production outputs, these systems empower refiners to confidently navigate the complexities of the market effectively. The commercial performance results underscore the tangible benefits of these technologies, demonstrating that refiners can achieve longer run lengths, lower pressure drops, and improved profitability. As industry continues to evolve, the importance of such innovative solutions will only grow, positioning refiners to meet both economic and environmental challenges head-on.

   

  Jan-2025