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Steam reforming is used for producing hydrogen in refineries and other industries like Fertilizer
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IOC R&D CENTRE
Mainak Sarkar & I. R. Choudhury
HGU Fundamentals and R&D Technical Services
COURSE ON “PETROLEUM REFINING TECHNOLOGY”Jan 31 – Feb 3 , 2011
IOC R&D Centre
IOC R&D CENTRE
Presentation Outline
• Overview – Hydrogen demand and supply sources
– Refinery Hydrogen Management
• Steam Reforming of Naphtha / NG– Process Fundamentals & Catalysts
– Poisoning of Catalyst
• PSA Purification• HGUs in Indian Refineries• HGU Facility at IOC R&D Centre
– Features of HGU Pilot Plant
• Tender Catalyst Evaluation – Evaluation Methodology
– Performance Criteria
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Hydrogen is Everywhere
Car
Refinery
Gas Station
Stationary FC
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Demand for Hydrogen H2 is essential in industrial process
World wide H2 consumption : 50 Million Tonnes per year
USERS CONSUMPTION, %
FERTILIZER INDUSTRY (AMMONIA) 57
REFINERIES 27
METHANOL 10
OTHER 6
Shell, 2004
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Hydrogen Production Routes
Raw material ProcessNatural Gas
Steam Reforming Refinery off-gasesLPGNaphtha
Kerosene, gas oilMethanol ReformingDMEAmmonia Cracking
Coal GasificationBiomass
Water Electrolysis
Nearly all H2 production is based on fossil fuels at present.
30%
48%
18% 4%
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Different Technologies
TECHNOLOGY STATUSSTEAM REFORMING COMMERCIAL
PARTIAL OXIDATION (POX) R&D / COMMERCIAL
AUTO THERMAL REFOMING (ATR) R&D / COMMERCIAL
GASIFICATION COMMERCIAL
THERMAL CRACKING R&D
WATER GAS SHIFT REACTION (WGS) COMMERCIAL
WATER ELECTROLYSIS COMMERCIAL (Small Scale)
THERMOCHEMICAL R&D
PHOTOCATALYTIC PROCESS R&D
PHOTO ELECTRIC R&D
PHOTO BIOLOGICAL R&D
FERMENTATIVE R&D
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Purification Techniques
• PRESSURE SWING ADSORPTION (PSA)– Based on differences in adsorption and diffusion of
different components • MEMBRANE SEPARATION
– Based on selective permeation through membrane• CRYOGENIC SYSTEM
– Based on differences in relative volatility of hydrogen and other impurities
• METAL HYDRIDE– Based on metal alloys; Used in semiconductor
industry
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PSA MEMBRANE CRYOGENICS
H2 capacity, mm scfd 1-200 1-50+ 10-75+
Feed H2 content, % >40 >25-50 >10
Feed pressure, psig/Mpa 150-600/1.03-4.13
300-2300/2.07-15.85
>75-1100/0.52-7.58
H2 product pressure Feed pressure Much lower than feed pressure
Feed pressure or lower
H2 recovery, % 75-92 85-95 90-98
H2 product purity 99.9+ 90-98 90-96
Pretreatment requirement None Minimum CO2, H2O removal
Multiple products No No Liquid hydrocarbons
Capital cost Medium Low High
Scale economics Moderate Modular Good
Comparison of Purification Systems
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Economic Analysis
20
40
70+
Pres
sure
, Bar
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Hydrogen Generation Statistics
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HYDRODESULPHURISATION
HYDROTREATING
HYDROCRACKING
HYDRO FINISHING
Why Refinery Needs Hydrogen ?
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Typical H2 Usage in Refinery
Process Hydrogen Requirement (Std. m3/BBL)
Hydrocracking 40 – 85HydrotreatingVGO 20 – 35 Distillates 10 – 20 Naphtha 5 – 15 Aromatics Saturation 5 – 15 Isomerization 1 – 5
more H2… H2… H2...Shrinking Refining Margin & Clean Fuel Mandate
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Hydrotreater Vents
Hydrocracker Vents / Purges
FCC Off Gas
Catalytic Reformer Off Gas
Purification of
Production by Steam Reforming of
oNatural GasoNaphtha
Partial Oxidation of o Fuel Oil
Sources of H2 in Refinery
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HYDROGEN PRODUCTION
BY
STEAM REFORMING OF NAPHTHA / NG
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Generic Hydrogen Plant Flowsheet
35 30 28 23 21 20Pressure, kg/cm2 g
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Objective of Each Section
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The main objective of pre-desulphurisation plant is to reduce the sulphur content in the sour naphtha feedstock for the hydrogen generation plant since sulphur is a poison for reformer catalyst .
The sour naphtha from the battery limit may contain up to 600 ppm wt Sulphur.
The sour naphtha is desulphurized in the PDS where the sulphur is converted to H2S which subsequently is removed in the Stripper.
The pre-desulphurisation unit is designed for removing the bulk sulphur in the naphtha feed in order to minimise the desulphuriser (ZnO) catalyst consumption in FDS section
RSH + H2 ↔ RH + H2S
RCI + H2 ↔ RH + HCI
RNH2 + H2 ↔ RH + NH3
R=R + H2 ↔ R-R
Pre-desulphurisation section (PDS)
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CoMoX Reactor I
Sour naphtha super heater
Fuel gas from b.l.
Naphtha stripper
Naphtha cooler
Naphtha separator
Sour water to b.l.
H2 compressor
Make up H2 from b.l.
vaporizer
Sour Naphtha
feed
Stripper reboiler
HP Steam
Feed product
exchanger
Sweet naphthato b.l.
Stripper overhead separator
Overhead condenser
Sour gas to b.l.
Overhead separator
TYPICAL BLOCK DIAGRAM OF PDS SECTION
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Typical Feed for PDS Section
Properties
Distillation Range C5 – 140 0C
Specific Gravity (15 0C) 0.723
Total Sulphur (ppmw) 600
Nitrogen (ppmw) 4
Chlorin (ppmw) 6
Hydrocarbon type (vol%)
Parafins 62.3
Olefins 0.5
Naphthenes 25
Aromatics 12.2
Total Metals ppbw 80
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Properties
Sulphur Content (ppmw) max 2
Nitrogen Content (ppmw) max 0.5
Metal Content (ppbw) Non traceable
Product and Operating Parameters Of PDS Section
Parameters Unit Value
Reactor Inlet/Outlet Temp (SOR/EOR) 0C 290/330292/333
Weighted Average Bed Temp (WABT) 0C 310
H2 Partial Pressure kg/cm2g 27
LHSV h-1 3.2
H2/Oil Nm3/m3 72
Typical Product Specification
Typical Operating Parameters
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This section consists of two reactors in series HDS Reactor Desulphurizer Reactor
HDS Reactor contains CoMoX type of catalyst and converts all type of organic sulphur and chlorine compounds to H2S and HCl
Desulphurizer Reactor contains Chlorine guard and Sulphure guard beds. Cl-guard removes HCl and S-guard removes H2S from the desulphurized naphtha stream
Allowable Sulphur and Chlorine slippage from FDS section is <0.2ppmw and < 0.1 ppmw respectively
Feed Desulphurisation Section (FDS)
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Operates at 350-400oC (WABT 392oC ) Temperature and 35 bar pressure
LHSV is very high i.e. In the range of 7-8 h-1
Major ‘S’ compounds present in Light Naphtha are COS, mercaptans, organic sulphides, disulphides, thiophenes and react as follows
RSH + H2 ↔ RH + H2S
Other impurities such as chlorine, nitrogens and olefins also get removed because of the side reactions
RCI + H2 ↔ RH + HCI RNH2 + H2 ↔ RH + NH3
R=R + H2 ↔ R-R
HDS Reactor
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ZnO acts as S-guard and absorbs H2S
ZnO + H2S ↔ ZnS + H2O
HCl reacts with Cl-guard which may contain Al2O3, NaAlO2 or Na2O Al2O3 + 6HCl 2AlCl3 + 3H2O Na2O + 2HCl 2NaCl + H2O HCl + NaAlO2 AlOOH + NaCl HCl + 2NaAlO2 Al2O3 + 2NaCl + H2O K2CO3+HCL 2KCL+H20+CO2
Since HCl reacts with the Zinc Oxide to ‘mobile’ ZnCl2, the chlorine guard bed is installed before the ZnO bed
The Desulphurizer Reactor acts as lead lag arrangement
In lead lag arrangement, the lag bed acts as a guard bed and lead bed takes the high sulphur loading. Once the lead bed gets exhausted the lag bed takes the load
Allowable H2S slippage limit for Lead bed is 10 ppmv; ‘S’ slip may increase with low operating temperature, high carbon dioxide or water content in the feed
Desulphurizer Reactor (Guard Bed)
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Lead Lag Arrangement
48-R-02 A 48-R-02 B
FromCoMox
Desulphurized Feed
R-A R-B
ZnObeds
ClGuard
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The main objective of Pre-reformer reactor is to convert higher hydrocarbons (C5-90) into lighter gaseous mixture containing primarily CH4, H2, CO and CO2
The main reactions occurring inside a pre-reformer are:CnHm + nH2O -----> nCO + (n +m/2)H2 (Endothermic)
∆H0298= 1175 kJ/mole (for n=7)
CO + 3H2 ↔ CH4 + H2O (Exothermic)
∆H0298= -206 kJ/mole
CO + H2O ↔ CO2 + H2 (Exothermic)
∆H0298 = - 41 kJ/mole
Pre-reformer is an adiabatic fixed-bed reactor
Pre-reforming is typically carried out at 480 -520 0C and steam to carbon ratio 1.8 – 3.0
Pre-Reforming Section
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Component Feed Composition (mol%)
Product Composition (mol%)
Naphtha 74.62 ---
Hydrogen 25.38 23.76
Methane --- 51.01
CO2 --- 24.84
CO --- 0.85
C2+ --- <0.2
A typical feed and product composition of a Pre-reformer
Note: Maximum allowable ethane and higher hydrocarbon (C2+) slippage is 0.2 mol%
Pre-Reforming Section contd..
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∆T across the Pre-reformer catalyst bed for different feed stock
Feed Type ∆T over the Cat bed (0C)
Natural Gas -25 to -30
Naphtha +15 to +20
Propane / Butane 0
0 0.5 1 1.5 2 2.5430440450460470480490500510520530
Temperature profile across the Pre-reformer catalyst bed
NaphthaNatural GasButane
Distance from the top the Cat Bed (m)
Bed
Tem
pera
ture
, deg
. C
Temperature Profile
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The key operating parameters for a pre-reformer reactor are:
Parameters Operating range
Pre-reformer inlet temperature, 0C 470 – 490
Pre-reformer inlet pressure, Kg/cm2 a 30 – 28
Pre-reformer outlet pressure, Kg/cm2 a 28 – 26
LHSV, Hr-1 2 – 2.5
Steam to Naphtha ratio, (Kmol/Kmol) 22 – 14
Pre-Reformer Operating Range
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Removal of Higher Hydrocarbons & larger Feedstock Flexibility
Flexibility in operation of Tubular Reformer w.r.t lower S/C ratio and higher feed preheat temperature
Protection of Downstream catalysts from poisoning of ‘S’ and other impurities
Capacity Increase
Overall Energy Savings
Advantages of incorporating Pre-reforming step prior to Reforming are:
Advantages of Pre-Reformer
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Pre-reformer catalyst is typically Ni based
The catalyst is supplied in Oxide form supported on some refractory material such as Alumina (Al2O3), Magnesium Oxide (MgO) etc
The catalyst is active in reduced form – Ni crystalNiO + H2 Ni + H2O
Normal expected life of pre-reforming catalyst is 1.5 to 2 yrs
Life assessment of pre-reformer catalyst is done by plotting Z- 90 curve with days of operation
Pre-reformer Catalyst
Z-90 = (Prereformer max. Temp. - Prereformer min. Temp.) x 0.90 + Prereformer min. Temp
The bed height corresponding to this temperature is called the Z-90 of prereformer catalyst
In case of NG feed, Z-90 is measured when the temperature becomes steady after endotherm
Z- 90 = Prereformer Max. Temperature - (Prereformer Max. temperature - Prereformer mini. Temp.) x 0.90
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Z-90 Curve
0 50 100 150 2000
500
1000
1500
2000
Pre Reformer Z 90
Days in operation
Be
d D
ep
th, m
m Abnormal
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Reforming section is the heart of the Hydrogen generation unit
The main objective is to produce Synthesis gas (CO + H2) from CH4
The reforming is highly endothermic and require external heat supply
Reformer reactor is a large furnace with multiple tube rows filled with catalyst running vertically along the furnace box
The normal inlet and outlet temperature of a typical reformer is 650-665 0C and 880-890 0C respectively
Reforming Section
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Component Feed Composition (mol%)
Product Composition (mol%)
Hydrogen 23.76 67.91
Methane 51.01 1.97
CO2 24.84 9.65
CO 0.85 20.47
A typical feed and product composition of a Reformer
Reforming Section contd..
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The main reaction occuring in Reformer is : CH4 + H2O ↔ CO + 3H2
with side reactions CH4 + 2H2O ↔ CO2 + 4H2
CO2 + H2 ↔ CO + H2O CH4 →C + 2H2
C + H2O↔CO+ H2
CO + 3H2 ↔CH4 + H2O
Process parameter affecting the equilibrium position:Process Variables Changes Hydrogen Yield Notes
Pressure Increase Decrease Plant economy dictates pressure parameter
Temperature Increase Increase Limited by tube metallurgy
Steam to Carbon Ratio Increase Increase Dictates by Plant Design
Reforming Reaction and Thermodynamics
(Endothermic) ΔH0298 = +205.9 kJ /mol
(Endothermic) ΔH0298 = +164.9 kJ /mol
(Endothermic) ΔH0298 = +41.0 kJ /mol
(Endothermic) ΔH0298 = +74.6 kJ /mol
(Endothermic) ΔH0298 = +131.3 kJ /mol
(Exothermic) ΔH0298 = -205.9 kJ /mol
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Parameters Operating range
Reformer inlet temperature, 0C 650 – 665
Reformer outlet temperature, 0C 885 – 890
Reformer inlet pressure, Kg/cm2 a 28 – 26
Reformer outlet pressure, Kg/cm2 a 24 – 23
GHSV, Hr-1 1500 – 1800
Steam to Methane ratio, (Kmol/Kmol) 2.8 – 3.0
The key operating parameters for a Reformer reactor are:
Reformer Operating Range
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Reformer furnaces are available in various geometry, tubes arrangement and burner arrangements
The most common types are: Top fired Box furnace (M/s Technip & Linde) Side fired Box furnace (M/s Haldor Topsøe)
Reformer Furnace
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Different Reformer Configurations
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Schematic Diagram of a Reformer Tube
Reformer Tube
CatalystInlet Pigtail
Top Flange Feed
CatalystSupport Grid
11.6 m
Tube metallurgy
35 Ni 25 Cr & Niobium
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Ni–based catalysts dispersed on various supports like γ-alumina, α-alumina, magnesium aluminate, calcium aluminate spinels etc.
In some cases ZrO2 is also used in the support for increase in stability
Promoters such as K2O, MgO, CaO, and SrO are used to minimize carbon formation; small amount of SiO2 prevents the evaporation of K2O and other alkali oxides
4-hole or 7-hole structure of reformer catalyst ensures high mechanical strength, thermal stability and low pressure drop
The performance of the Reforming catalyst is measured in terms of methane slippage in the reactor effluent
Reforming Catalyst
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Johnson Matthey (46-3Q)
Topsøe (R-67-7H)
Component
Ni Oxide, wt% 23 >12
Other oxides, wt%(K2O, ZrO2, SiO2)
7 <0.2
Support Balance Balance
Typical average crush strength (kg) (radial)
100 100
Shape
Typical chemical properties of steam reforming catalyst from different vendors
Catalyst Properties
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Shift conversion stands for Water Gas shift reactionCO+ H2O ↔ CO2 + H2 H0
298 = - 41 kJ/mol
The main objective of this section is to enhance the hydrogen yield and at the same time reduces the emission of CO
Thermodynamics:Slightly ExothermicPressure has no effect on the equilibriumAt high temperature, this is equilibrium controlled reaction
Depending up on the reaction temperature and catalyst type, shift reactors can be further classified as
• High temperature shift reactor – HTS• Medium temperature shift reactor – MTS• Low temperature shift reactor – LTS
Shift Conversion Section
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Shift Type Inlet Temp( 0C) Outlet Temp(0C)
HTS 340-350 410-420
MTS 200-205 330-340
LTS 200-205 220-230
The general configuration for the shift converter section is either HTS followed by LTS (Technip, Linde) or MTS followed by LTS (Topsøe)
Some time only HTS or only MTS may also present
In the HTS reactor because of the unfavorable equilibrium, the CO conversion is low compared to MTS reactor. On the other hand, HTS catalyst is more resistance to sulphur poison
CO slippage is the controlling criterion for the shift reactor performance
Shift Conversion Section contd..
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Component Composition (mol%)
HTS inlet HTS outlet LTS inlet LTS outlet
Hydrogen 66.2 69.6 69.6 70.8
Methane 5.5 4.9 4.9 4.7
CO2 11.6 20.6 20.6 23.8
CO 16.7 4.8 4.8 0.7
Component Composition (mol%)
MTS inlet MTS outlet LTS inlet LTS outlet
Hydrogen 67.91 72.47 72.47 73.16
Methane 1.97 1.69 1.69 1.65
CO2 9.56 22.51 22.51 24.44
CO 20.47 3.33 3.33 0.75
Inlet / Outlet composition of Shift Converter
Shift Conversion Section contd..
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HT Shift Catalyst
HT shift catalyst is based on Fe3O4 promoted with Cr2O3 to prevent sintering
The typical composition of HT catalyst is 90 wt% Fe3O4 & 10 wt% Cr2O3
For activation the catalyst is reduced in situ in a controlled atmosphere of H2 & CO
The active form is a spinel with composition FeIIFeIII2-xCrxO4
Excess steam is used during activation to avoid the formation of metal carbide
This catalyst is tolerant to sulfur and chlorine compounds
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A typical composition of MT Shift catalyst includes ZnO:Cr2O3:CuO= 1:0.24:0.24 with 2% –5% MnOx, Al2O3 and MgO promoters
The typical composition of LTS catalyst is 32-33 wt% CuO, 34-53 wt% ZnO and 15-33 wt% Al2O3
MTS and LTS catalysts are sensitive to sulphur and chlorine in feed
Both MT/LT shift catalysts need to be reduced with H2 to form the active species Cu
Reduction reaction is exothermic and temperature excursions above 230-250°C may cause catalyst sintering; so H2 is diluted with N2
MT / LT Shift Catalyst
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Sulphur - Ni is good sulphur absorbent (One atomic layer) Detected by hot spots on the surface of reformer tubes – hot bands, hot patches, giraffe necking and increase of methane slippage at exit of reactor
Poisoning of Catalyst
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Chlorine - usually present as organic Cl or HCl - is similar to sulphur
- accelerates the sintering of the metal crystallites - serious poison for Cu shift catalyst (MTS/LTS)
Arsenic - found in naphtha feedstock - severe and irreversible catalyst poison - also contaminates metal of pipework and reformer tubes
Si, P & Alkali - found in liquid feedstock - poison the reforming catalyst
Olefins - Highly exothermic; 1.0 % ethylene in NG leads to increase of 29 0C - carbon formation
Poisoning of Catalyst contd..
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The objective of this section is to enrich Hydrogen in the HGU effluent
Pressure Swing Adsorption (PSA) route is used in general
Principle: Desired component is adsorbed at high pressure while impurities are rejected at low pressure
Adsorbents used:• Na- Silicates: for H2O adsorption• Activated charcoal for CO2 removal• Molecular sieves for CO/CH4 removal
Multi vessel systems. One vessel is in adsorption while the others are in various stages of regeneration.
Waste stream from the PSA (Purge Gas) is burnt in the Reformer as fuel
Purification Section: PSA Unit
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Quality
Hydrogen mole% >99.99
Methane + Carbon dioxide+ Carbon monoxide ppmv <20
Nitrogen Mole% Balance
Chlorides + Chlorine ppmv <1
Water (dew point at 1atm.) 0C -80
Total sulphur ppmv <1 ppmv
Total nitrogen (excl.N2) ppmv <1ppmv
Molecular mass Kg/kmol 2.02O/L Pressure Kg/cm2g 20.0O/L Temp. 0C 40-45
Hydrogen Quality at PSA outlet
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Typical PFD of a PSA System
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HGUs in Indian Refineries
HGU in IndianOil Operated / Subsidiary RefineriesS. No. Refinery Unit Licensor Capacity, MTPA Year of
Commissioning1
GujaratHGU-I Linde A G 38000 1993HGU-II Haldor Topsøe 11000 1999HGU-III Haldor Topsøe 72500 2010
2Panipat
HGU-I Haldor Topsøe 38000 1999HGU-II (A/B) Haldor Topsøe 70000 (2 Chains) 2005
3Mathura
HGU-I Haldor Topsøe 34000 1999HGU-II Technip 60000 2005
4Haldia
HGU-I Haldor Topsøe 15000 1999HGU-II Technip 75000 2010
5Barauni
HGU-I Haldor Topsøe 34000 2002HGU-II Linde A G --- Under construction
6 Guwahati HGU Technip 10000 20027 Digboi HGU Technip 7000 20038
CPCL* HGU-I Technip 16064 1999HGU-II Technip 56000 2004
* Indian Oil Subsidiary company
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HGU in Other Indian Refineries
S. No.
Owner
Refinery Unit Licensor Capacity, MTPA
Year of Commissioning
1 HPCL Vishak Refinery Technip 18000 2000Mumbai Refinery Haldor Topsøe 14500 2000
2 BPCL Mumbai Refinery (HGU-I) Haldor Topsøe 14500 1999Mumbai Refinery (HGU-II) Haldor Topsøe 45000 2005Kochi Refinery (KRL) Technip 18650 2000
3 NRL Numaligarh Refinery Haldor Topsøe 38000 20004 RPL Jamnagar Refinery Linde A G 165000 20055 MRPLHGU-I Technip 20000 1996
HGU-II Technip 23000 1999
HGUs in Indian Refineries contd..
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Refinery PDS FDS/HDS Pre-Reformer Reformer Shift PSA bedsGujarat HGU-II Yes Yes Single Reactor Side Fired MT only 1 x 5Gujarat HGU-III Yes Yes Single Reactor Side Fired MT & LT 2 x 6
Mathura HGU-I No Yes Single Reactor Side Fired MT only 1 x 101 x 5
Panipat HGU-I No Yes Single Reactor Side Fired MT & LT 1 x 10
Panipat HGU-II (A/B) Yes Yes Single Reactor Side Fired MT & LT 1x12(2 chains)Haldia HGU-I Yes Yes Single Reactor Side Fired MT only 1 x 5
Barauni HGU-I No Yes Single Reactor Side Fired MT & LT 1 x 10
Units Designed by M/s Haldor Topsøe
Refinery PDS FDS/HDS Pre-Reformer Reformer Shift PSA bedsGujarat HGU-I No Yes No Top Fired HT only 1x10
Mathura HGU-II Yes Yes Two Reactors Top Fired HT & LT 1 x 12
Haldia HGU-II Yes Yes Single Reactor Top Fired HT & LT 1 x 10Guwahati HGU No Yes Single Reactor Top Fired HT & LT 1 x 10
Digboi HGU No Yes No Top Fired HT only 1x5
Units Designed by M/s Technip & M/s Linde
Different HGU Plant Configurations
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GENERAL BLOCK DIAGRAM OF HGU BY HTAS
Naptha Pump
NaphthaVaporiser
NAPTHA(FEED)Surge Vessel
PreheaterHydrogena
tor
CL guard/Sulphur
guard
CL
gu
ard
/S
ulp
hu
r g
ua
rdP
re-R
efo
rme
r
I D
Fa
n
Boiler
MT
sh
ift
Co
nve
rte
r
LT S
hift
C
on
vert
er
BFW Exchangers
BFWExchanger
Deaerator
DMWPreheater
Fin FanCoolers
Process Con.Vessels
CW
E
xch
an
ge
r
PSA UNIT
H2 TO HDT
H2 Recycle Comp
H2
R
EF
OR
ME
R
STA
CK
Steam Drum HP Steam
H P STEAM FOR PROCESS & EXPORT
F D
Fa
n
FU
EL
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GENERAL BLOCK DIAGRAM OF HGU BY OTHER LICENSORS
Naptha Pump
NaphthaVaporiser
NAPTHA(FEED)Surge Vessel
PreheaterHydrogena
tor
CL guard/Sulphur
guard
CL
gu
ard
/S
ulp
hu
r g
ua
rdP
re-R
efo
rme
r
I D
Fa
n
Boiler
HT
sh
ift
Co
nve
rte
r
LT S
hift
C
on
vert
er
BFW Exchangers
BFWExchanger
Deaerator
DMWPreheater
Fin FanCoolers
Process Con.Vessels
CW
E
xch
an
ge
r
PSA UNIT
H2 TO HDT
H2 Recycle Comp
H2
R
EF
OR
ME
R
STA
CK
Steam Drum HP Steam
H P STEAM FOR PROCESS & EXPORT F D Fan
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HYDROGEN GENERATION UNITS
AT
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Hydrogen generation Unit
Water Electrolizer
Pilot Scale Steam Reformer
Supplies Hydrogen for Hydroprocessing
Pilot Plants
Catalyst Evaluation and Data generation for different projects
Hydrogen Generation Facility
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HGU Pilot Plant Facility
HGU PILOT PLANT
• HGU Pilot plant is the 1st of its kind in India
• Indigenously designed by R&D centre and
fabricated by M/s Xytel India
• Miniature Steam Reformer
• It can exactly simulate the operating parameters
of any commercial unit
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Objectives of HGU Pilot Plant
Catalyst selection & evaluation from different vendor and recommendation of the same to refineries
Kinetic data generation for in-house model development
Optimization Studies Trouble shooting Feed and product evaluation Catalyst health monitoring / deactivation studies Competitors technology assessment Development of new technologies
With model application
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Different Sections of Pilot Plant
• Liquid feed section– Naphtha Tank + Weighing Balance– DM water tank + Weighing Balance– Feed Pump for Naphtha– Pumps for DM water– Naphtha Vaporizer– Steam generator
• Gas Feed Section– H2, N2, CH4, CO2, CO & Natural gas (NG)– Mass flow controllers for each gas– Drier for each gas
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• FDS Section– Hydrogenation
– Desulfurization (Sulfur and Chlorine guard beds)
• REFORMER Section– Pre-Reformer– Reformer
• SHIFT Section– High/Medium Temperature Shift (HTS/MTS)– Low Temperature Shift (LTS)
Or a combination of these
Reactor Section
Different Sections of Pilot Plant contd ..
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• Gas/Liquid separation section– High pressure Separator (HPS)– Pressure control valve– Level control valve– Condensate collection tank + Weighing balance– Wet Gas meter (WGM)– Off gas sampling arrangement
Different Sections of Pilot Plant contd ..
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S
GAURD
Cl
GAURD
NAPHTHA PUMP
NAPHTHA TANK
NAPHTHA HEATER
FOR GAS ANALYSIS
WET GAS METER
CONDENSATE WATER
WATER PUMP
WATER TANK
STEAM GENERATOR
HYDROGEN
R EFORMER
SULPHURREMOVAL
R-400 HIGH PRESSURE SEPARATOR
R-600R-300 R-500
P REREFORMER
NITROGEN
METHANE
NATURAL GAS
CO2
CO
TO R- 400, 500, 700 & 800
TO R- 300, 400, 500, 700 & 800
TO R- 300, 400, 500, 700 & 800
TO R- 400
TO R- 500 & 700
TO R- 500 & 700
PFD of HGU Pilot Plant
IOC R&D CENTRE
R-800
CONDENSATE WATER
HIGH PRESSURE SEPARATOR
FOR GAS ANALYSIS
WET GAS METER
R-700
WATER PUMP
WATER TANK
STEAM GENERATOR
FROM R-600
HTS / MTS
REACTOR
LTS
REACTOR
PFD of HGU Pilot Plant contd..
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Operating Range
• REACTOR CAPACITY : Cat volume: 50 - 100 cc
• OPERATING TEMPERATURES : – 450oC max for HDS & Guard Bed Reactor– 600oC max for Pre reformer – 950oC max for Reformer – 550oC max for HTS/MTS – 350oC max for LTS Reactor
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• PRESSURE : – 50 bar max for HDS/ Pre reformer/ Reformer– 35 bar max for HTS/ LTS Reactor
• NAPHTHA FEED RATE : 20 - 450 ml/h (C5 - 1000C)
• WATER FLOW RATE : 60-600 ml/h
• FEED GAS FLOWRATE : – 10-500 SLPH for NG, CH4, CO, CO2 – 16-800 SLPH for H2
Operating Range contd..
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Additional Features of HGU Pilot PlantPLC system for remote controlState of the art instrumentation for measuring all
major operating parameters during start-up, shutdown and normal operation
Five internal Thermocouples in each reactor for adjusting catalyst bed temperature
Flexible operation– All 6 reactors in series– Any one reactor or reactors in combination–Separate sampling arrangement for each
reactor–By-pass of HDS section for sulfiding & start-up
6 Reactors in series –Electrical heaters for each reactor.
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Off gas sampling arrangements GC for online/off line off gas analysis
Provision of steam startup line to check steam qualityProvision for slop tankWater de-aeration facility Emergency pump for waterComprehensive safety features
– Temperature safety switch for each reactor
– Pressure safety valve & Rupture disc in each reactorUPS for bake up power supply
Additional Features of HGU Pilot Plant
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Feed / Product Characterization FacilitiesFeed/product N, S, Cl AnalyzerFeed naphtha ASTM, SIMTBP, sp. gr and detailed component analysis DM water quality analysis (TDS etc)
Catalyst CharacterizationSurface area, pore volume analyzerXRD & XRF for catalyst chemical compositionCrushing strength measurement (Side Crush Strength for Reformer Catalyst)Apparatus for Bulk Density measurement
Additional Features of HGU Pilot Plant
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Tender Catalyst Evaluation
• PDS / FDS Catalyst
• Pre-Reformer Catalyst
• Reformer Catalyst
• HT – Shift Catalyst
• MT – Shift Catalyst
• LT – Shift Catalyst
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Steps involved in Tender Cat Evaluation
Catalyst ex-situ drying (if recommended by vendor)
Sizing of catalyst (only for Reformer catalyst)
Catalyst Loading
Catalyst reduction by vendor’s recommended procedure
Determination of the operating parameter
Steam start-up through start-up line
Start Feed
Set operating parameters
Stabilization
Product gas analysis& Material Balance
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Sizing of catalyst (Only for Reformer Catalyst)
Reformer catalyst size is bigger than reactor annular space The catalyst are broken. Then the broken catalyst are sieved. Catalyst of particular size range are taken for loading Bulk Density (BD) is determined
Catalyst Loading: Following parameters need to be considered for determining the loading volume
LHSV / GHSV Maximum Feed pump capacity Maximum Water pump capacity Minimum and maximum limit of MFC
Step Details
)(
)/(,
)(
)/(3
3
3
3
mlumeCatalystVo
hmGasrateGHSV
mlumeCatalystVo
hmFeedrateLHSV
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Heating zone-1
Top Dead end
Pre-Heating Zone
Catalyst Bed
CATALYST BEDALUMINA BALLS
Internal Thermocouple position
QUARTZ WOOL
Post-Heating Zone
Heating zone-2
Heating zone-3
Heating zone-4
Bottom Dead end
Thermo-well
Inlet
Out let
Typical Reactor Loading Diagram
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Determination of the operating parameter Feed rate
Naphtha rate (Pre-reformer catalyst) LHSV Gas rate (Reformer, HTS, MTS & LTS catalyst) GHSV
In case of synthetic feed Synthetic feed composition Based on refinery’s
reactor outlet composition. Steam rate Based on refinery’s Steam/gas ratio
Set operating parameters Temperature (Inlet / Outlet) Pressure (Inlet) Feed rate Gas rate Steam rate
Material Balance: Error limit (± 2 %)
Operating Parameters
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Tender Catalyst Evaluation Criteria
CATALYSTS PERFORMANCE PARAMETERS
HDS ‘S’ Slippage
ZnO ‘H2S’ Slippage
Prereformer Ethane & higher HC (C2+) Slippage
Reformer Methane Slippage
Shift (HT / MT / LT) CO Slippage
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CATALYSTS GUARANTY COMPOUND SLIPPAGE
HDS 0.2 ppm wt. Organic sulphur max
Pre-reformer 0.2 vol % C2+ dry basis (max)
Reformer 3 – 4.5 vol % CH4 dry basis (max)
HT Shift 6 vol % CO dry basis (max)
MT Shift 3.9 vol % CO dry basis (max)
LT Shift 1.0 vol % CO dry basis (max)
Typical Tender Evaluation Criteria
Tender Catalyst Evaluation Criteria
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Pre-Reformer Catalyst Evaluation
COMPOSITION OF EXIT GAS, VOL %
COMPONENTC2
+ fraction vol%
H2 CO CO2 CH4
COMMERCIAL PLANT Trace 23.7 0.2 17.8 58.3
VENDOR-A Trace 23.4 0.8 17.69 57.71
VENDOR-B Trace 23.03 0.79 17.18 57.98
VENDOR- C Trace 21.9 0.77 17.6 59.73
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Reformer Catalyst Evaluation
Component Commercial Plant
Vendor-1 Vendor-2
CH4 4.1 2.79 2.33
H2 66.8 69.32 69.61
CO 18.9 18.51 19.30
CO2 10.1 9.38 8.76
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CATALYST COMPOSITION OF EXIT GAS, VOL %
COMPONENT H2 CO CO2
COMMERCIAL PLANT 74.6 0.8 19.4
VENDOR- A 75.45 1.82 22.73
VENDOR-B 75.41 1.87 22.72
VENDOR- C 75.49 1.63 22.88
MTS Catalyst Evaluation
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CATALYST COMPOSITION OF EXIT GAS, VOL %
COMPONENT H2 CO CO2
COMMERCIAL PLANT 75.4 0.4 18.4
VENDOR-A 73.69 0.72 25.58
VENDOR-B 73.99 0.46 25.55
LTS Catalyst Evaluation
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Steps involved in running Pilot Plant
Catalyst ex-situ drying (if required)
Catalyst Loading Catalyst reduction (Pre-reformer, Reformer, HTS/MTS & LTS) as per vendor’s procedure
HDS section start-up (In case of sour naphtha )
Sulphiding as per vendor procedure (use by-pass line) Normal HDS operation till product sulfur < 1 ppm Divert HDS outlet to Sulfur guard bed
Steam start-up through start-up line
Feed start-up / Divert Sulphur guard (R-400) outlet to Pre-reformer
Stabilization
Product gas analysis , Material Balance and Yield calculation
All the reactors in series
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Conclusions
• Hydrogen Generation Unit is an integral part of todays’ Refinery configuration
• Understanding of different sections of HGU plant is essential for better monitoring/ troubleshooting, optimization and revamp studies
• IOC R&D Centre offers the state-of-the-art HGU catalyst evaluation facility for tender catalyst evaluation
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Thanks
