Novel Approach to Ammonia Plant Revamps with ZoneFlow Reactor - PowerPoint PPT Presentation

ZoneFlow TM Reactor Technologies, LLC Novel Approach to Ammonia Plant Revamps with ZoneFlow™ Reactor Technology SANJIV RATAN & Michael Ralston ZoneFlow Reactor Technologies, LLC (ZFRT), USA Prof. Juray de Wilde, Universite Catholique De Louvain (UCL), Belgium

Presentation Outline  Introduction  Steam Reforming “pellet” catalyst - Status quo  ZoneFlow TM (ZF) Reactor Technology - an innovative breakthrough  ZF development status and validation programs  Application of ZF Reactor Technology in ammonia plants • ZF Single-Pass Reactors (ZF-SP) • ZF Convective Pre-Reforming Reactors (ZF-CPR) • ZF for Post Reforming (ZF-PR) Confidential information of ZONEFLOW REACTOR TECHNOLOGIES, LLC 2

Introduction  Projected global growth for nitrogen fertilizers: 2% per year  Ammonia plant revamp / expansion is the potential driver  Expansion often constrained by primary reformer / SMR (dP, TSM, firing)  Proven solutions in place for typical 20-30% additional capacity but often constrained by existing SMR (mainly catalyst ) limitations Confidential information of ZONEFLOW REACTOR TECHNOLOGIES, LLC 3

Ammonia Plant Syngas Generation Front-end Confidential information of ZONEFLOW REACTOR TECHNOLOGIES, LLC 4

Steam Reforming Pellet Catalyst - Status Quo  Inherent deficiencies of the conventional "pellet" steam reforming catalyst, limiting reformer capacity increase: • high pressure drop • catalyst attrition / breakage from thermal cycling • limited heat transfer and associated higher tube temperatures • flow / temperature non-uniformity due to random packing • very low catalyst effectiveness Confidential information of ZONEFLOW REACTOR TECHNOLOGIES, LLC 5

ZoneFlow Reactor Technology – an Innovative Breakthrough  Advanced high-performance structured catalyst  Step improvement of key performance parameters • up to 2 times higher heat transfer (along with internal radiative transfer) • up to 70% lower pressure drop • up to 10 times higher catalyst effectiveness • high strength metal substrate; longer stable life • annular flexible casing; near-wall flow jets • adaptive structure for Convective pre-reforming Confidential information of ZONEFLOW REACTOR TECHNOLOGIES, LLC 6

Conventional SMR Catalyst v/s ZF Reactors  from random packing to engineered foil structure; also non-acidic and steam stable  from limited surface (GSA) enhancement Conventional ZoneFlow TM pellet structured to high GSA fin structure catalyst Catalyst  from strength-limited voidage of ~ 50 % to ~ 90% voidage with robust substrate  ZF offers step reduction in dP combined with multifold increase in heat transfer Confidential information of ZONEFLOW REACTOR TECHNOLOGIES, LLC 7

Conventional SMR Catalyst v/s ZF Reactors  from diffusion-limited active site access to micro-layered full surface access  from random packing tube wall contact to flexible casing for uniform proximity to wall Conventional ZoneFlow TM pellet structured catalyst Catalyst  Increased catalyst effectiveness ; higher resistance to coking and upsets ; longer life  from limited crush strength against thermal cycling to durable metal substrate  No attrition from thermal cycling; stable dP and flow uniformity over full operating life Confidential information of ZONEFLOW REACTOR TECHNOLOGIES, LLC 8

ZF CFD Modeling (dP and Heat Transfer) 1.E+02 250% New SMRs Relative Heat Transfer Coefficient 1.E+01 200% Empty tube Revamps hf / dP/dz 1.E+00 150% Different ZF Casing Designs 1.E-01 100% 1.E-02 50% 1.E-03 0% 5.E+01 5.E+02 5.E+03 5.E+04 5.E+05 5.E+06 0% 50% 100% 150% 200% dP/dz Relative Δ P Confidential information of ZONEFLOW REACTOR TECHNOLOGIES, LLC 9

ZF Kinetic Modeling and FEA Analysis Confidential information of ZONEFLOW REACTOR TECHNOLOGIES, LLC 10

ZF Commercial Demonstration Installation Extraction Operation Confidential information of ZONEFLOW REACTOR TECHNOLOGIES, LLC 11

Demonstrated Results Compared to Pellet Tubes  80 o C lower TMT  24% lower pressure drop  No hot spots  ZF operation >15,000 hrs with several thermal cycles  Lower S/C ratio operation was not available Confidential information of ZONEFLOW REACTOR TECHNOLOGIES, LLC 12

ZFRT Pilot Plant  At Materials and Process Engineering (IMAP) Division in Université catholique de Louvain (UCL), Belgium  Facilities and campaigns for extensive testing of ZF reactors under various commercial conditions and beyond  In collaboration with Professor Gilbert Froment  Operational 2Q 2018 Confidential information of ZONEFLOW REACTOR TECHNOLOGIES, LLC 13

ZFRT Pilot Plant Installation Confidential information of ZONEFLOW REACTOR TECHNOLOGIES, LLC 14

Ammonia Plant Revamps  Revamp approaches • ZF-SP reactors replacing pellets to allow capacity increase without added dP or increase in tube temperatures • Adding ZF-CPR Reactors in primary reformer convection zone to utilize high grade convective heat for producing additional hydrogen instead of steam • Use of ZF-PR reactors in post-reformers or heat-exchange reformers for step capacity increase , which are inherently heat-transfer limited and capital intensive Confidential information of ZONEFLOW REACTOR TECHNOLOGIES, LLC 15

Typical Reforming Section of a Ammonia plant 500-550 o C 450-500 o C 950-1000 o C 780-820 o C H2/N2 vol. ratio ~3 0.3-0.5% CH 4 10-13% CH 4 Confidential information of ZONEFLOW REACTOR TECHNOLOGIES, LLC 16

ZF-SP Reactors for Stressed SMRs  Stressed SMR Indicators / Attributes • Pressure drop (and build up) limiting throughput • Loss of catalyst activity and related heat transfer or Shorter EOR activity • Hotter tubes / Hot spots • Carbon formation at inlet • Catalyst bridging / settling from thermal cycling • Shorter (remaining) tube life  Replacing (pellet) catalyst in these SMRs with ZF-SP Reactors can overcome these deficiencies Confidential information of ZONEFLOW REACTOR TECHNOLOGIES, LLC 17

ZF-SP for De-Stressing of SMR SMR Stressed ZF-SP replacing SMR De-Stressing Design Operation pellets Relative Capacity, % 100 95 100 Capacity limitations - dP, TSM removed S/C Ratio 3.3 3.5 3.2 Outlet temp, C 800 793 804 Approach to Equilibrium EOR C -10 -12 -7 CH4 slip, vol % 12 12 12 Radiant Pressure drop, bar 2.8 2.8 2.3 Relative Radiant duty % 100 97 99 Avg. Heat flux kW/m2 75 72 75 Bridgwall temp, C 950 950 948 Max. Tube Skin temperature C 860 860 857 Confidential information of ZONEFLOW REACTOR TECHNOLOGIES, LLC 18

ZF-SP Reactors for Debottlenecking  Achieve capacity in excess of nameplate (~ 105 %), while utilizing design margins in SMR burners and fans  Higher average heat flux without exceeding tube design temperature  Improved temperature uniformity  Extended tube life and improved reliability and availability  Better catalyst performance and “life cycle” costs  Extended EOR  Optimized operation and reforming severity Confidential information of ZONEFLOW REACTOR TECHNOLOGIES, LLC 19

ZF-SP for Debottlenecking Reference ZF-Radiant Relative Capacity, % 100 105 Capacity limitations dP, TSM removed S/C Ratio 3.3 3.1 Outlet temp, C 800 810 Approach to Equilibrium C -10 -7 CH4 slip, vol % 12 12 Radiant Pressure drop, bar 2.8 2.5 Relative Radiant duty % 100 103 Avg. Heat flux kW/m2 75 77 Bridgwall temp, C 950 950 Max. Tube Skin temperature C 860 860 Confidential information of ZONEFLOW REACTOR TECHNOLOGIES, LLC 20

Pre-reforming In-situ efficient use of higher grade convective heat using existing process coils ZoneFlow TM Adiabatic pre-reforming Mixed feed (APR) Radiant Zone Adiabatic Pre- Steam reformer Methane Flue gas to stack Convective zone Syngas Confidential information of ZONEFLOW REACTOR TECHNOLOGIES, LLC 21

ZF Convective Pre-reforming (ZF-CPR)  Non-adiabatic convective pre-reforming using ZF-CPR inserts  In-situ horizontal loading in the mixed feed superheat coils  Avoids major modifications around the primary reformer and also the related extended downtime  Tailored structured packing for very low dP, high GSA and (low temp reforming) activity  Further optimization of dP in combination with ZF-SP in SMR radiant tubes  For revamps, up to 15% additional reforming without increasing SMR firing duty. Confidential information of ZONEFLOW REACTOR TECHNOLOGIES, LLC 22