SMR PRE-REFORMER DESIGN: Case Study

Refinery Process Stream Purification Refinery Process Catalysts Troubleshooting Refinery Process Catalyst Start-Up / Shutdown
Activation Reduction In-situ Ex-situ Sulfiding Specializing in Refinery Process Catalyst Performance Evaluation Heat & Mass
Balance Analysis Catalyst Remaining Life Determination Catalyst Deactivation Assessment Catalyst Performance
Characterization Refining & Gas Processing & Petrochemical Industries Catalysts / Process Technology - Hydrogen Catalysts /
Process Technology – Ammonia Catalyst Process Technology - Methanol Catalysts / process Technology – Petrochemicals
Specializing in the Development & Commercialization of New Technology in the Refining & Petrochemical Industries
Web Site: www.GBHEnterprises.com
GBH Enterprises, Ltd.
SMR PRE-REFORMER DESIGN
Case Study #0618416GB/H
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SMR Pre-Reformer Design: Case study
Objective: Evaluation of a proposed SMR Pre-Reformer design.
Background
Pre-Reformers
 React hydrocarbon feed with steam to give a methane rich product
suitable for further downstream reforming.
 Pre-reforming works as an adiabatic steam reforming step over a Ni based
catalyst.
 The basis for the reforming may be considered
as the reaction between a hydrocarbon and steam
• steam / methane reaction
• water / gas shift reaction
Typical Pre-Reformer Installation:

SMR Pre-Reformer Design: Case Study #0618416GB/H
Contents
1. SMR Pre-Reformer Design
2. Inlet Baffle Design
3. Outlet Collector
4. Hold Down Grating
5. Floating Hold Down Screen
6. Catalyst Drop Out Nozzle
7. Thermowell Detail
8. Technical Performance requirements
9. SMR Pre-Reformer Isolation
Technical Review and Commentary on Proposed Design
APPENDIX
A. Operating / Mechanical Data
B. Materials Specifications
C. Fabrication and Inspection Requirements
D. Weights
E. Nozzle Data
F. Instrument Connections
G. Manholes

SMR Pre-Reformer

Inlet Baffle
INLET BAFFLE NOTE:
1. Number, size and placement of support vanes by EPC contractor
minimum 4 vanes required.
2. Final design and details by EPC contractor.

Outlet Collector
Table of Dimensions
Nozzle Specifications:
A, o
C: 198
B, mm: 25
Open Area, m2
: 0.56
ΔP, bar: 2.86
C, mm: 25
D, o
C: 250
Notes:
1. Uniformly perforate elliptical head with (“A”) “B” Dia. Holes pitch may be
square or triangular.
2. Collector must withstand tabulated DP plus bed weight.
3. Open area tabulated is effective (i.e., hole area x wire screen open area)
4. Final design and details by EPC Contractor. Supplied by vessel vendor.

Hold Down Grating
Notes:
1. Vessel vendor to install (2) sets of continuous rings at indicated elevations
shown on sheet 6 to accommodate catalyst bed heights depending on
which catalyst supplier is used. The continuous rings above hold down
grating from overturning while allowing up and down movement. Rings to
be welded to the shell.
2. Minimum open area is 70%.
3. Final design and details by EPC contractor.

Floating Hold down Screen
Note:
1. Wire Screen to be 6 x 6 x 1.19 mm Diameter wire.
2. Vessel vendor shall supply sufficient 1.0 mm diameter wire for field use to
lace screen sections together along the overlaps.
3. Match mark sections for field installation. Screen sections and ring
segments must pass through vessel manhole.
4. Final design and details by EPC Contractor.

Catalyst Dropout Nozzle

Thermowell Design Details

SMR Pre-Reformer Isolation

Technical Review and Commentary on Proposed Design
Bed Temperature Measurement:
Bed temperature measurement is provided via a single thermo-well. There is no
indication of the number of measurement points this will contain. For a vessel of
this diameter a single thermo-well does not provide adequate coverage through
the vessel.
Pre-reforming catalysts should not be allowed to come into contact with liquid
water. The proposed temperature control arrangement (both upstream and
downstream of the reactor) provides a potential source of water to enter the
system. In any future statement with respect to pre-reformer performance it will
be assumed that water injected upstream of the pre-reformer feed pre-heater will
be fully vaporized before coming into contact with the catalyst bed.
Should this be found to not be the case in ultimate operation of the plant this will
invalidate any performance guarantees that may be offered at the time of catalyst
purchase.
Note: Without additional information we are unable to comment on the
suitability or otherwise of the proposed temperature control arrangement.
Inlet Gas distributor:
GBHE has no experience on this type of design and cannot comment on its
performance. The inlet pipe does not meet the GBHE’s ‘straight length’
requirement and hence even more importance is placed on the good
performance of the distributor itself. Good distribution is essential to ensure even
flow through the bed.
Hold Down Grid:
It is proposed to place a hold down grid on top of the bed together with a wire
mesh. Use of a wire mesh can lead to the potential risk of a partial blockage
resulting in mal-distribution in flow. The use of wire mesh screens in the reactor
is unacceptable.

Outlet Collector:
The outlet collector is, shown as covered by a wire cloth. As mentioned above
the use of wire mesh is unacceptable in the reactor.
Isolation system:
The sketch shown indicates that on an emergency shutdown the pre-reformer is
automatically bypassed and the reactor isolated. Apparently it is intended that the
bypass be used to maintain production during catalyst change out, or perhaps it
is a feature in the proposed start-up or shut down sequence?
Without more knowledge of the overall operating philosophy to be used GBHE is
unable to provide any detailed comment on adequacy of the proposed
arrangement.
Flaw List:
The list provided makes reference to the possible presence of BTX in the feed
but does not state how much.
Pre-Reforming catalyst can tolerate aromatic compounds and will successfully
operate in the presence of such components. The levels present may impact on
life of the catalyst and this can only be evaluated at the time of the catalyst
enquiry when performance/guarantee levels are being considered.
Inert Ballast:
Three types of inert materials are recommended. GBHE experience suggests
that only material of the following specification is acceptable;
Al2O3 99.0 wt% (min)
SiO2 0.2 wt% (max)
TiO2 0.5 wt % (max)

APPENDIX
A. Operating Data
Working temperature 515 0
C
Working Pressure 27.5 bar ga
Design temperature, upper / lower 535 / 4 0
C
Design pressure 33 bar ga
Vapor 79.08 kg/s
Molecular Weight 17.8
Density at working temperature 7.81 kg/m3
Mechanical Data
Diameter of Shell ID 3500 mm
Length between Tangent Lines 2500 mm
Height of skirt to bottom tangent line 7300 mm
Type of Heads Hemispherical
Wall Thickness
Shell 110 mm
Top Head 56 mm
Bottom Head 56 mm
Corrosion allowance 3 mm
Insulation thickness 200 mm (Hot)
Catalyst Volume 25.5 m3

B. Materials Specifications
Shell EN 10028-2 10CrMo9-10 Downcomers
Cladding/lining of Shell N/A Baffles
Heads EN 10028-2 10CrMo9-10 Internal Pipe
Fittings
Cladding/lining of Heads N/A Stud Bolts External
Reinforcing rings N/A Nuts External
Skirt (Top 2000mm) EN 10028-2 10CrMo9-10 Bolts Internal
Skirt Balance ASTM A516 – Gr.70 Nuts Internal
Jacket N/A Gaskets Internal
Shell flanges N/A Gaskets Internal
Nozzels prEN 10216-2 10cRmO9-10 “
(DN 350 and smaller)
Nozzles prEN 10216-2 10cRmO9-10 “
(DN 400 and larger)
Flanges (ASME) EN 10222-2 11CrMo9-10 Internal Wire
Screen
Flanges (Non-ASME) EN 10222-2 11CrMo9-10 Hold Down Grating
Welding fittings prEN 10216-2 10cRmO9-10 Floating Hold
Down rings
Stiffening rings N/A
Insulation Support Rings As Shell
Cleats for platforms, etc. As Shell
Internal Parts As Shell

C. Fabrication and Inspection Requirements
Inspection Authority Client Third Party, including
design review
Stress relieving Yes, per code
Special heat treatment Yes, EPC Contractor
Radiography Per Code
Other Non-destructive Testing Per Code
Chemical Analysis See GBHE
D. Weights
Erection weight (shipping weight) 58,000 kg
Total weight operating 105,000 kg
Total Weight Full of Water 124,000 kg
Max O/T Moment at Base 500 kNm
Max Base Shear 70 kN
E. Nozzle Data
Vapor In DN 750 CL 900 # RFLWN
Vapor Out DN 750 CL 900 # RFLWN
Drain DN 80 CL 900 # RFLWN
Utility Connection DN 50 CL 900 # RFLWN
Catalyst Unloading Connection DN 200 CL 900 # RFLWN
F. Instrument Connections
Diff Press Indicator DN 50 CL 900 # RFWN
Thermowell DN 80 CL 900 # RFWN
PG DN 50 CL 900 # RFWN
G. Manholes 600 I.D. CL 900# RFLWN

SMR PRE-REFORMER DESIGN: Case Study

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