nartc 2025
and achieving a net-zero emissions solu- tion during normal operation. The proposal for Option 1 also included the following modifications: • Simplified system: Fewer exchangers reduced complexity. • Reduced flanges and piping: Led to cost savings and easier installation. • Increased complexity: Additional equipment in the low-pressure section of the unit made the implementation more difficult. • Reactor #1 inlet control: A bypass of the heat exchangers was proposed for tem- perature control during normal operation. Additionally, a bypass of the fired heater would optimise the reaction section loop overall differential pressure in normal operations, allowing a lower recycle gas compressor utility consumption. Although Option 1 offered numerous advantages, it was ultimately not selected due to its impact on the stripper reboiler caused by the introduction of stripping steam, which would result in: • Higher capital and operational costs: The addition of a vacuum dryer system and utilities would significantly increase both capital and operational expenditures. • Increased complexity: The inclusion of additional equipment in the low-pressure section of the unit would make implemen- tation more challenging. Option 2: Optimised heat exchanger and heater solution Option 2 was chosen for its simpler design and greater cost-effectiveness: • Heat exchanger replacement: Six con- ventional heat exchangers were replaced by two STHEs, reducing the HAT from
• Simplified design: Fewer exchangers and piping led to reduced costs and easier implementation and maintenance. • Operational similarity: The design main- tained process continuity, allowing for seam- less integration into the existing operation. Cost Considerations In both options, the heat exchangers’ costs were similar, but Option 2 offered lower overall costs due to its simpler design. By eliminating the vacuum dryer and related equipment, Option 2 avoided significant capital expenditure. The electrical radi- ant heater further reduced fuel consump- tion and CO₂ emissions, making it the more cost-effective solution. Conclusion Axens Group’s offering for the DHT revamp project positions it to successfully increase capacity to 40,000 BPSD while target- ing CO₂ emissions reduction. Although Option 1 offers net zero emissions, its complexity and high costs make it less via- ble. Option 2 involves replacing traditional heat exchangers with STHEs distributed by Nectis and transitioning the heating source from a fired heater to a unique elec- tric tubular radiant heater designed by Heurtey Petrochem Solutions. This option provides an efficient, cost-effective solu- tion that aligns with both operational and environmental goals. This practical case study demonstrates the value of integrat- ing advanced technology with careful cost considerations to enhance refinery perfor- mance and sustainability.
Water injection
STHE-2
STHE-1
Reactor 2
Feed
1 Electric Tubular Radiant Heater
Reactor 1
2 Spiral Tube Heat Exchangers
Stripper
H
Air cooler
Makeup
Diesel
HP separator
Hex reboiler
BP separator
Advanced Technology equipment flow scheme: Option 2
Existing ow scheme
2 18 ˚F (10˚C) 16.3 MMBTU/h (e-heater) (4.8 MW) Advanced technology equipment ow scheme – Option 2
6 81 ˚F (45˚C) 51.6 MMBTU/h (15.1 MW)
No of exchangers: Hot approach Heaters duty Electricity cost : (1)
-2.4 MM USD/year 3.1 MM USD/year 1.8 MM USD/year 2.5 MM USD/year
– – – –
(2) Fuel savings :
Emission savings : (3)
Total savings
(1) Considering an electricity cost of 17.7 USD/MMBTU (2) Considering a fuel cost of USD/MMBTU (3) Considering CO emission cost of 70 USD/ton
CO savings ≈ 25,000 tons/year Zero emissions at Process Unit
Petrochem Solutions. This is presently the only proven electrical technology available on the market for hydrocarbon processing, enabling the achievement of net zero emis- sions at the unit level.
81ºF (45ºC) to 18ºF (10ºC) and reducing heater duty by 68%. • Fired heater replacement: The fired heater was replaced with an electrical tubular radiant heater, supplied by Heurtey
Contacts: Sindy.STONE@heurtey.net Jan.RENETEAU@nectis.net
Crystaphase optimisation helped refiner achieve up to double runtime and throughput
Austin Schneider Crystaphase
tor’s foulant profile, the Crystaphase team could turn to their data modelling capabil- ities for a projection of the pressure drop over the next year. The customer received some good news: the system would likely continue to perform without dP limitations over an extended cycle. The projection from Crystaphase was accurate, and when Cycle 1 completed, the hydrocracker’s runtime and through- put doubled with the Crystaphase optimi- sation. Since the completion of Cycle 1, other successful cycles have followed, with Crystaphase optimisations assisting. The most recently completed run was a full cycle without a pressure drop increase, shutting down at approximately 80% of the Cycle 1 runtime. The current cycle is on track to repeat the performance of Cycle 1, once again doubling the cumulative throughput. Conclusion With the guidance and technology of Crystaphase, operation has become much more stable over the long term, and pres- sure is no longer an imminent threat to the refinery’s cycle goals.
mid-cycle skim of the hydrocracker pre- treat reactor, Crystaphase installed an ActiPhase ® TRANS solution designed with enough capacity to reach the next sched- uled changeout, about one year later, with- out dP limitations. With the system installed, the cus- tomer met that goal. When the reactor was shut down for a scheduled full cata- lyst changeout, the customer installed an optimised ActiPhase system designed, together with Crystaphase, to extend the cycle length even further. Over the duration of that cycle, the reactor suffered several unrelated setbacks, including equipment failures. Despite all of these events, the pressure drop remained virtually flat after each restart. Through the mid-point of the hydroc- racker’s first complete cycle (Cycle 1) with the Crystaphase solution, the pressure drop appeared to remain effectively flat. Given the impressive results, the customer approached Crystaphase to see if the sys- tem could continue past its next sched- uled shutdown. Due to their work with the customer and understanding of the reac-
Not long after a summer turnaround, a major Gulf Coast refinery had a problem. The engineering team noticed a pressure drop (dP) increase in bed 1 of their hydro- cracker pretreat reactor shortly after start- up, all but guaranteeing they would not meet their cycle length goal without per- forming a mid-cycle skim. The site’s chal- lenges did not end there. A year later, they experienced an unexpected two-hour equipment shutdown. Upon restart, the team observed a dP increase in bed 2 while the state of bed 1 continued to worsen. The engineers had little time to dream about extending the cycle length; they needed just to keep the reactor online and running at the required rates. As in most refineries, the hydrocracker needed to deliver consistently high throughput for stable operations and to meet demand. The refinery’s engineers knew that the increased pressure drop could limit the hydrocracker’s performance. With their standard configuration, which utilised tra- ditional grading, the runtimes were short. Downtime from mid-cycle skims reportedly ranged from 20 to 60 days. At high-com-
plexity facilities, disruptions like these can seriously impact availability, profitability, and risk associated with turnaround and maintenance operations. Having worked with Crystaphase to solve tough challenges at other locations, the engineers turned to the company‘s filtra- tion technologies to deliver results with a novel, empirically based solution to a com- mon reactor problem: pressure drop due to crust layer formation. Working with the site’s process engi- neer, Crystaphase collected samples from two previous cycles to analyse and better understand the reactor’s foulant profile. After lab analysis of these samples, the Crystaphase team identified the foulants that appeared most likely to be contribut- ing to pressure drop. tailored solution From this detailed analysis, Crysta- phase’s process and development engi- neer, Umakant Joshi, and director of tech- nology, Austin Schneider, developed a tailored solution that could optimise the reactor’s configuration. Following the next
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