As product specifications grow more stringent, successful production depends on reactor internals that can outperform standard distribution tray technology. Conventional distribution trays, even advanced bubble-cap designs, are notorious for low uniformity of vapour–liquid distribution and undesirable thermal maldistribution. Shell reactor internals can outperform existing distributor tray technology. 

With an improved nozzles lay-out, the latest generation SHELL High-Dispersion (HD2) trays offer uniform liquid-gas distribution over the catalyst bed for a wide range:

  • liquid-gas rates and ratios (Low Gas HD Tray for low gas flowrates processes) 
  • feed qualities (Dirty Duty HD Tray for fouling feeds) and applications (HCU, DHT, Chemicals…)
shell high-dispersion trays

About the technology

Shell HD trays have benefited from extensive experiments in Shell Global Solutions’ pressurised testing facilities, advanced computer simulations and more than 25 years of experience in Shell and non‑Shell refineries.

The substantially high-performance profile of Shell HD trays makes them essential components in any hydroprocessing reactor, especially when paired with other Shell reactor internals such as the Shell ultra-flat quench (UFQ) interbed internals. Even in retrofit applications, Shell HD trays offer performance benefits by lowering start-of-run temperatures, decreasing catalyst deactivation and raising end-of-run weighted average bed temperatures. They boast an extremely low occurrence of stagnant zones and channelling for a wide range of operations along with a reduced susceptibility to tilt and fouling (see Figure 1).

Technology description

Owing to their excellent vapour–liquid and thermal distribution, Shell HD trays function equally well as top distribution and interbed distribution trays to aid full catalyst utilisation throughout the reactor. Also, unlike other distributors’ designs that require a deep layer of inert distributive packing, Shell HD trays enable the reactor beds to be filled with active catalyst.

Shell’s proprietary nozzle design harnesses vapour momentum to create overlapping coverage, which improves wetting, even in severe fouling applications. In addition to improved production performance, the mechanical configuration of each tray is engineered for easy boltless access, cleaning and catalyst loading, all of which improve turnaround time significantly.

Shell HD trays enable the reactor to operate efficiently for a wide range of feed rates and types (typically −70 to +50% of the normal operating feed rate). This is true for both liquid and gas feeds, although operation with gas feed only is also viable.

In addition to improving catalyst utilisation thereby enabling a longer cycle length, higher throughput or improved product specification, the optimised mechanical design of the HD trays provides a shorter and safer installation time.

Business Value

Upcoming fuel trends demand new hydroprocessing methods. Shell Global Solutions strives to equip refiners to meet these trends using proprietary reactor internals technology.

Shell HD trays have the potential to vastly improve refiners’ cycle lengths through slower catalyst deactivation, lower inlet temperatures (as required for stringent product specifications) and improved thermal distribution. Documented case studies have demonstrated higher throughput capacity and the ability to process heavier feeds. In one case, Shell HD trays offered up to 30% higher utilisation of the catalyst for hydrotreating reactors and up to 50% more for hydrocracking reactors. Ultimately, Shell HD trays offer improved reactor performance while minimising capital expenditure and investment costs.

Have you considered how you can:

  • Increase cycle length and throughput?
  • Improve catalyst usage?
  • Increase production despite heavier feedstock?
  • Develop new, quality products that meet clean fuel specifications?
  • Improve safety and cut turnaround times during and after a revamp?
  • Process more difficult feeds?

If you answered yes to any of these questions, Shell Global Solutions would like to discuss with you how to help improve your operations and boost your margin. Contact us.

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Fouling Abatement

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About Reactor internals

Shell’s latest-generation reactor internals technology is applied to grass-roots units and is used for replacing lower-performing trays in revamps. Shell has over 25 years of operational experience with reactor internals.