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CO2 Capture Project Phase 3 – Oxyfuel Large Scale Pilot and Demonstration Projects 2nd Oxyfuel Combustion Conference
12 – 16 September 2011
Capricorn Resort Yeppoon – Australia
Presenter:Leonardo F. de Mello Petrobras - Brazil
The CO2 Capture Project (CCP) The CO2 Capture Project (CCP) is an award-winning partnership of seven major energy companies working to advance the technologies that will underpin the deployment of industrial-scale CO2 capture and storage (CCS)
CO2 Capture Project
• Phase 1 – 2001-2004 – completed Technology Screening/Proof of Concept • Phase 2 – 2004-2009 – completed Intensive Development • Phase 3 – 2009-2013 – On going Demonstration Funded by a number of methods, including: • Full or Associate membership of the partnership • Government grants • In-kind contributions
Current members: BP (Program Operator), Chevron, ConocoPhillips, Eni, Petrobras, Shell & Suncor and associate member EPRI
CCP program objectives
In order to help make CCS a practical reality and utilised in many different industries and applications around the world, the CCP aims to accomplish the following goals:
Increase technical and cost knowledge associated with CO2 capture technologies and confirm that geological storage of CO2 is a secure and viable means of reducing greenhouse gas emissions
Reduce CO2 capture costs by 20-30% by supporting the development of improved technologies
Quantify remaining assurance issues surrounding geological storage of CO2 through site assessments, field surveys and numerical approaches; and rapid dissemination of results to stakeholder groups
Validate cost-effectiveness of monitoring developments with design and testing of emerging and integrated systems
Cooperate with interested parties to share information about both capture and storage demonstrations
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Oxy-combustion in Once-Through Steam Generator - OTSG
Three Phase Project: •Phase I (completed): Develop design basis and cost estimates for test and commercial scale OTSG
•Phase II (2011-13): Demo oxy-fuel combustion on 50 MMBTU/hr test boiler •Phase III (proposed): Demo oxy-fuel combustion, compression and purification on test boiler
Overall Objective: To demonstrate that oxy-fuel combustion is a safe, reliable and cost-effective technology for CO2 capture from once-through steam generators
Funding Partners: Cenovus Energy (host site), CO2 Capture Project, Devon, Praxair, Statoil, Meg Energy Technology Providers: Praxair – industrial gas & combustion technology TIW Western – boiler technology Image courtesy of Cenovus
The Oil Refinery Scenario
CO2 Emission Sources at a Typical Refinery Complex
RISER
Products - Gasoline - LPG - Propane
Typical Feeds - Vacuum Gasoil - Atmospheric Resid Steam
Air
REGENERATOR
Flue gas
10 – 20 % CO2
Overview of FCC converter
RISER
Products
Feed
Steam
REGENERATOR
O2 + CO2
O2
ASU
H2O
85 % CO2
Air
Oxy-combustion in FCC
CO2
Points of attention
• Enhanced heat removal from the catalyst bed • Catalyst fluidization and entrainment rates • Enhanced catalyst deactivation – O2 partial pressure • Combustion rates
Possible impacts in the process may come from different gas properties: Cp CO2 > Cp N2
ρ CO2 > ρ N2
Test Program
1) Same heat removal
Air
O2 N2
H
Oxy
O2 CO2
H
2) Same volume flow rate
Air
O2 N2
H
Oxy
O2 CO2
H
3) Same cyclones solids loading
Air
O2 N2
H
Oxy
O2 CO2
H
- Each condition will be tested with two types of feed - Two long term tests will be made to evaluate catalyst loss and deactivation - The flexibility obtained in condition 2 will be used to test an additional condition with increased feed rate
FCC Large Scale Pilot Unit
Capacity: cat. Inventory = 300 kg; feed flow rate = 200 kg/h (30 bpd) VGO; 1t/d CO2 emission
FCC Testing Unit
Catalyst inventory
Feed flow rate
x 150 x 280 to 2000
x 200 x 580 to 2000
Typical pilot plant
Test unit Full
scale unit
FCC Unit Retrofit
FCC Unit
Feed
Products
Air Flue gas
Air - fired operation
FCC Unit
Feed
Products
Flue gas
Oxy - combustion operation
CO 2 Recycle System - SOx scrubber - Compressor - Storage tank
Chemicals
Recycle gas
(CO 2 rich )
O 2 Supply System - Tank - Vaporizer - Control Skid
Liquid Oxygen (Lox)
Oxygen
CO 2 rich Flue gas
Waste water
Water
FCC Unit Retrofit
Oxygen Supply System
FCC Unit Retrofit
CO2 Recycle System
• Includes: catalyst fines and SOx removal unit, compressor, chiller, CO2 storage tank and piping;
FCC Unit Retrofit
Pre-operation
Objective: perform short oxy-combustion trials to evaluate the operability of the entire system, identify possible limitations of the units and anticipate problems so that the test program may be entirely carried-out Learnings: FCC unit oxy-combustion operation: - Air to oxygen transition is very fast and simple. However, there must be a close monitoring of excess O2 in flue gas since it may reach very low levels as recycling occurs Action taken: constant adjustment of O2 flow rate during transition
Excess O2 in Flue Gas
-2.0
0.0
2.0
4.0
6.0
8.0
10.0
12.0
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Time
wt%
Online O2LAB - O2
Oxidant flow rate
0.0
50.0
100.0
150.0
200.0
250.0
300.0
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Time
Kg
/h AirO2+CO2
Flue Gas Composition
0.010.020.030.040.050.060.070.080.090.0
100.0
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Time
% v
ol
LAB - CO2LAB N2Online CO2
Oxidant gas composition
-
5.000
10.000
15.000
20.000
25.000
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Time
% v
ol
Pre-operation / Air-O2 transition
• Air
• O2+CO2+N2
% v
ol, d
ry
% v
ol, d
ry
% v
ol, d
ry
Pre-operation
Learnings FCC unit oxy-combustion operation: -The starting regenerator temperature is critical for stable operation. As the gas is recycled, this temperature significantly decreases and coke burn rate in the regenerator is affected. Action taken: unit was adjusted to start operation at higher regenerator temperatures and a combustion promoter was used Recycle Compressor - After all oxy-combustion trials, the recycle compressor showed low efficiency and solid deposits were found inside both compression stages which obstructed suction and discharge valves. - The solid deposits were analyzed and the results suggest they are corrosion product from the presence of sulfuric acid. Action taken: adjustments in operation conditions and use of alternative materials improved compressor efficiency
Pre-operation
Preliminary Results
Product Yields, wt%
Base CaseOxyfuel - same inert flow rate
Fuel gas 3.0 3.9LPG 14.9 18.9Gasoline 43.2 41.7LCO 16.8 15.4Bottoms 17.9 15.2Coke 4.2 5.3Total 100.0 100.4Conversion 65.3 69.4
Same inert volumetric flow rate condition
- Air operation: 80,4 Nm3/h of N2
- Oxyfiring operation: 79,5 Nm3/h of N2+CO2
Base CaseOxyfuel - same inert flow rate
CO2 0 69.6O2 21 23.1N2 79 7.3
CO2 14.8 87.9O2 4.7 3.5N2 80.5 8.5
Recycle gas
Flue gas
Component%vol, dry
Final Remarks
The technical viability of oxy-firing an FCC unit has been demonstrated on a large scale pilot test unit
The transition from air to O2 and back was shown to be fast and simple, however care must be taken with the excess oxygen in flue gas
Corrosion inside the recycle compressor was observed as the oxycombustion flue gas has a very strong acidic property. Adequate handling of the gas is critical for long term operation.
The first result, in the same inert volumetric flow rate condition, showed an increase in feed rate conversion and the latest results indicate a CO2 content in flue gas close to 94% (dry basis)
Thank you!