Foil Supported Catalysts Deliver High
Performance in Steam Reformers
Matthew Humphrys
25 Mar 2015
Westin Hotel Gurgaon, India
CATACELJM SSRTM
Patented foil supported catalysts deliver major
performance improvements to steam reformers
What is it, how does it work?
How does it compare to conventional pellets?
How is it deployed?
What is our experience in real reformers?
What can I expect in my plant?
What can I expect in a new plant?
Catalyst Pellets Heat Transfer
Catalyst promotes turbulence at tube wall by passively breaking-up the laminar gas film
Smaller pellets create more points of contact at the tube wall
Small pellets give higher heat transfer
Limitations arise from pressure drop
Thick "film" - Low HTC
Thin "film" - High HTC
Large Pellets
Small
Pellets
Structured Catalyst Heat Transfer
Structured catalyst promotes turbulence at tube wall by actively jetting the gas onto the gas film at the wall
Jets do not need high velocity to create high heat transfer
Voidage of structured catalysts >90%
Lower pressure drop than pellets for improved heat transfer
Thick "film" - Low HTC
Thinnest "film" - High HTC
Pellets
Structured
Catalyst
Catalyst is delivered as a coating
High temperature alloy foils shaped into a flexible
fan
Usual steam reforming catalyst materials coated
on the surface
Two decades of experience coating
catalysts on foils
Excellent adhesion in severe emission control
applications
Fans in stacks
Fans and rings formed in stacks 0.25 - 1.0 m each
Patented structure in the center
Facilitates deployment & removal
Ensures correct relationship between fan edges and tube wall
Active surface ~1.5 x QUADRALOBE (Q) pellets
More activity and longer life
Pressure drop ~0.8 x Q pellets
Heat transfer ~1.3 x Q pellets
More throughput or less fuel
Properties readily configurable
Flow impinges on tube wall
Impingement confirmed by CFD
CFD Modelling
SSR pressure drop similar to GQ
SSR heat transfer 30% higher than GQ
SSR step change in performance
Installed using patented tool technology
Reduces temperature in can reformer
Reduces fuel in can reformer
High performance expected in wide
range of plants
Hydrogen plant uprate
Ammonia plant production increase
Methanol plant throughput increase
PRIMARY reformer model and other tools used to estimate performance
Hydrogen plant uprate
Plant designed to use naphtha, now on natural gas
Customer looking for 15% additional capacity
Limited by reformer Tube Wall Temperature (TWT) of 890C
Balance of plant is capable
Solution: CATACELJM SSR in the reformer
Higher heat transfer reduces TWT
Allows 15% feed increase
TWT at the original 890C
Pressure drop similar to current
Efficient only 12.5% increase in firing
Ammonia plant production increase
Customer looking for more ammonia production
Primary reformer limited by TWT 892C
Summer, also limited by combustion air flow
Solution: CATACELJM SSR in primary reformer
Higher activity reduces approach to equilibrium
Methane slip reduced, some TWT reduction
Higher heat transfer also reduces TWT
Allows 2% higher fuel firing (yearly average)
Same feed, slightly higher outlet temperature
Lower slip from primary reformer
2.6% increase in ammonia production
TWT much lower, 875C, tubes last longer
Methanol plant throughput increase
Customer with side-fired reformer wants more production
Limited by combustion air
Bottom row burners are throttled to limit TWT
Solution: CATACELJM SSR in reformer
Higher activity & higher heat transfer
Reduced approach, less slip, lower TWT
Allows a bias of the burners towards the bottom with same total firing
Burner system is more efficient, 50C lower flue gas temperature
Increase feed 4.5%, same slip, similar TWT
4.4% increase in methanol production
Slightly lower pressure drop
New reformers
What happens if we design a new reformer to take
full advantage of the unique properties of
CATACELJM SSR?
New reformers
Higher activity and heat transfer
For similar TWT
Allows tubes with thinner walls
Less tubes needed for same heat transfer duty
Lower pressure drop
Allows less tubes
Allows longer tubes
Up to 15% less capital for the reformer
Terrace wall hydrogen plant reformer
Catalyst QUADRALOBEJM CATACELJM SSR
Number tubes - 352 322
Number tube rows - 2 2
Tube ID mm 108.0 111.4
Tube OD mm 132.0 132.0
Tube wall thickness mm 12.0 10.3
Tube heated length m 13.72 14.00
Furnace length m 36.03 32.95
Furnace width m 2.00 2.00
Heat load MW 134 134
Catalyst pressure drop bar 3.31 3.31
Minimum tube wall margin C 34 34
Relative cost % 100.0 90.2
Conclusions
CATACELJM SSR brings a significant improvement in reforming catalyst technology
Catalyst coated on foil substrate
Higher heat transfer, more activity, similar pressure drop
Has been demonstrated in two plants
Others coming on-stream in near future
Delivers major performance benefits to steam reformers
More capacity, especially when plant is operating at a limit
Capital cost up to 15% less with new plant designs
Thank you