1
Janusz Kertynski, Dr Bernhard Schreiner
Budapest, 13-14 October 2015
Increased flexibility of refineries by O2 enrichment.Sulphur recovery and new opportunities.
3
Actual needs of refining industry Efficiency increase and process excellence
• Low prices of crude oil (sustainable?)
• Growing demand on gasoline in Europe
• Tighter environmental regulations
• Refining capacity growth in Asia and the
Middle East
• Safety
• Flexibility
• Reliability
• Best possible utilization of
existing infrastructure
• Revamps and investments in
new infrastructure
• Need for low CAPEX solutions
4
Linde GasApplications for refineries and petrochemical industry
• Inertization of tanks, terminals, railway
tankers, road tankers etc.
• Nitrogen Services – Purging, drying,
pressure testing, temporary sourcing etc.
• Cryogenic condensation of volatile
compounds
• Industrial water treatment – e.g. pH
adjustment with CO2
• Reduction of NOx emission with use of
Ozone
• Oxygen enrichment in Sulphur Recovery
Units
• Oxygen enrichment of Fluid Catalytic
Cracking
• Oxygen enrichment in process fired
heaters (New development)
6
Effect of oxygen enrichment on flow of process air
Overall flow with same amount of oxygen at different enrichment levels
0
10
20
30
40
50
60
70
80
90
100
20 30 40 50 60 70 80 90 100
O2 concentration [%]
Flow
rate
[m³/h
]
Nitrogen
Total flowrate
7
Oxygen enrichment in Sulphur Recovery UnitsDescription of Claus Process for Sulphur Recovery
WHB
Thermal Stage Catalytic Stages
BurnerAcid Gas
Air(Oxygen)
RXNFURN
CatalyticConverters
Sulphur pit
SulphurCondensers
Reheaters
To TGTU
incinerator
2H2S + 3O2 2SO2 + 2H2O
Overall Chemistry: 2H2S + O2 2S + 2H2O
2H2S + SO2 3S + 2H2O
2H2S + SO2 3S + 2H2O
8
Oxygen enrichment in Sulphur Recovery Units3 Modes
Low level EnrichmentMedium level
Enrichment
High level Enrichment
(Double Combustion)
Enrichment Up to 28 % Oxygen Up to 45 % Oxygen Up to 100 % Oxygen
Add gaseous Oxygen
(GOX)
into existing air
blower discharge
Directly into
combustion zone
Stepwise into
combustion zones
(interstage cooling )
Adjustment at air-
based Claus unit for
revamp by O2
enrichment
Insert oxygen injector
into process air pipe
Substitution of the air-
based burner by new
burner (SURETM type)
Substitution of air-
based burner by new
burner(SURETM type)
&
Various measures like
e.g. installation of a
second waste heat
boiler
Capacity Increase Up to 35 % Up to 75 % Up to 150 %
9
Oxygen enrichment in Sulphur Recovery UnitsCapacity Increase
Case example:
3 CUs of same capacity are
operated (max. Sulphur
production 100 tons/day
– routinely all at a load of
80% of design capacity
In case one CU faces shut-
down the two other CUs left
running can take over the
load of the un-operated unit
by applying O2e running at a
load of 120 tpd
Capacity increase for Dp = constant(measured)
0
10
20
30
40
50
60
70
80
90
20 25 30 35 40
O2 [vol%]
Capa
city
incr
ease
[%]
90% H2S CW 90% H2S measured
50% H2S CW 50% H2S measured
10
Oxygen enrichment in Sulphur Recovery Units Ammonia (NH3) in Claus units
Precipitation of ammonium salts acc. to
NH3 + H2O + SO2 NH4HSO3
Often causes:
• Reduced plant availability
• Less Sulphur recovery efficiency
• Enhanced effort for plant maintenance
• Reduced throughput
Remedy: Improvement of Claus furnace operation
• Increased temperature
• Higher residence time
• Better mixing of the reactants
O2 enrichment to be considered
11
Oxygen enrichment in Sulphur Recovery Units Ammonia
(NH3) in Claus units – Measurements
Measured Ammonia destruction effects
Air, 21 vol.-% O2
Enriched air, 27-28 vol. -% O2
Different Claus units
0
300
200
100
NH3
[vppm]
A B C D E
Sampling of
Claus process gas
12
Trial results - mode 1: H2 demand *
AG + SWS gas + Air 100 %
AG + SWS gas + Air (less) + O2 (i.e. 26% enriched) 73 %
Trial results - mode 2: H2 demand *
AG + Air 100 %
AG + Air (less) + O2 (i.e. 26% enriched) 62 %
Enhanced H2 partial pressure in the Claus process gas
reduces fuel gas consumption at the tailgas unit
* Amount of H2 to be added up-stream the hydrogenation step
Oxygen enrichment in Sulphur Recovery UnitsHydrogen savings at the tailgas unit (SCOT-type)
13
Gaseous
Oxygen
(GOX)
Central process control system
Controller
Air and oxygen toClaus main burner
Air
Gas distributor
Measuringand
controlunit
O2 analyzer
Tank / vaporizer
Equipment to be delivered by Linde
Equipment in refinery
Oxygen enrichment in Sulphur Recovery UnitsHydrogen savings at the tailgas unit (SCOT-type)
14
Oxygen enrichment in Sulphur Recovery UnitsTrials with O2 enrichment (Low level): Scope & hardware
Service offer:
• Consulting/Studies – Identification/verification of needs and bottlenecks
• Realisation of field trials out of one hand with low cost
• Tailored hardware solutions for oxygen supply/dosing/injection
• Ammonia services (sampling/analysis)
• Trial report and recommendation of target/fixed solution
OXYMIXTM Flowtrain and controller at the
plant site
OXYMIXTM Injector for safe
and efficient mixing of
oxygen into the process air
Portable tank (ISO Container) and
containerised vaporiser
15
1. FCC reactor 2. Regenerator 3. Boiler 4. Fractionation 5. Recycle oil
Gasoil
Gasoline
Crack gas
Steam Steam
Off-gas
Recycle oil
Residue
4
5
2
1
3
Vacuum gasoil
Oxygen
Regeneration air
O2 enrichment in FCC Processing
16
O2 enrichment in FCC Processing
Oxygen enrichment at the FCC regenerator is typically applied:
• If the air blower of the regeneration is limiting
• If the velocity in the regenerator is too high - abrasive effects and catalyst losses
• For increase of throughput of FCC feed
Oxygen enrichment at the FCC regenerator is proven technology which has the potential to:
• Increase flexibility towards heavier feeds, load changes and light products
• Increase capacity
• Reduce catalyst losses
• Improve economy substantially
17
Oxygen enrichment in process furnaces – OPFGeneral process description
Idea
Use Oxygen to improve furnace performances with low CAPEX:
• Higher capacity
• Higher efficiency
• Less NOx
Technology Basis
Injection of Oxygen stream in new burners or existing ones with
specific layout.
When?/Benefits
• Capacity increase
• Better flexibility – reduced influence of fuel composition changes
• Solving draft problems (overpressure issues)
• Improving flame stability - avoid impingement and big flames
• Higher fuel efficiency due to reduced amount of flue gas and
improved exchange in convection section
• Suitable for both natural draft and forced draft systems
18
Linde burner design and test center - Italy
Oxygen enrichment in process furnaces - OPFScope and services
• Consulting/Studies – Identification/verification of needs and bottlenecks
• Design review of the furnace (Linde Gas + Linde Engineering)
• Equipment supply (OXYMIXTM Flowtrain + OXYMIXTM Injector , burners)
• Burner testing
• Assistance for start-up
• Performance monitoring
• Gas supply
19
Oxygen enrichment in refining processes Summary
Oxygen enrichment comes with
• Increased plant capacity
• Increased flexibility (technically and conceptually)
• Potential fuel savings
• Improved combustion – e.g. NH3 destruction in Claus units
• Low CAPEX
Claus O2 enrichemnt trials – Refinery LOTOS 2014
Thank You
Contact information:
Dr Bernhard Schreiner - [email protected]
Janusz Kertynski – [email protected]
Thank You
22
Back-upOPF - Impact on NOx emission
NOx Reduction possible - Induced stratified combustion and induced flue gas recirculation due to specific layoutand burner design
Typic. Heater vs O2 Enriched heater
Typ. O2 Enrich.
H.R. ( MW) 1.43 1.43
O2 in C.A. ( %v) 21 24
NG flow (kg/hr) 108 108
O2 flow (Nm³/h) 0 52
Air flow (Nm³/h) 1600 1200
Pressure drop 100% 75%
NOx emissions 100% 76%