Mathieu Lucquiauda, Laura Herraiza, Hannah Chalmersa, Jon Gibbinsb
a School of Engineering, University of Edinburgh, The King’s Buildings, Edinburgh, EH9 3JL, UKb Department of Mechanical Engineering, University of Sheffield, Sheffield, S1 3JD, UK
UKCCSRC PROGRAMME CONFERENCE 4-5th September 2019, Edinburgh, UK
Integration Options for Low-Carbon Hydrogen and Power Synergies (WP AC4)
Presentation outline
Low-carbon Hydrogen and Electricity in CCUS ClustersResearch objectivesIntegrating an Hydrogen plant & a gas turbine power plant Steam methane reforming (SMR) hydrogen plant downstream of a H-class Gas Turbine Gas-heated reformer (GHR) downstream of an aeroderivative Gas Turbine
Key findingsNext Steps
• Hydrogen and electricity are two key low-carbon vectors with a valuable role for the long-term decarbonisation of the whole energy system.
Low-carbon H2 and Electricity in CCUS clusters
• Both vectors may be generated in low-carbon CCUS industrial clusters and benefit from a common infrastructure for natural gas supply, electricity grid and transport and geological storage of CO2.
CCUS Cost Challenge Taskforce report, 2018 3
• Objective: Capital cost reduction of the CO2 capture system
Efficient and flexible thermodynamic integrationallowing for flexible generation of low-carbon hydrogen and electricity.
• This work investigates synergistic design options for simultaneous generation of low-carbon hydrogen by steam methane reforming (SMR) and low-carbon electricity in combined cycle gas turbine (CCGT)
SMR
CCGT
Carbon Capture
Carbon Capture
GT SMRCarbon Capture
Base
Cas
eIn
tegr
ated
Sy
stem
Low-carbon H2 and Electricity: Research objectives
Natural GasAir CO2-depleted Flue Gas
Natural GasAir
Natural GasAir
Heat
Flue Gas
Heat
Flue Gas
Heat
Flue GasFlue Gas
Natural Gas
Steam cycle
Flue Gas
CO2
CO2-depleted Flue Gas
CO2
CO2-depleted Flue Gas
CO2
H2
H2
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Low-carbon H2 and Electricity: Background
• The integrated system is based on the concept of sequential combustion applied to combined cycle gas turbine power pants (CCGT) and steam methane reformers (SMR), where the excess oxygen in the gas turbine exhaust gas (ca. 10- 14 vol% O2 ) is used as the source of oxygen for combustion in the SMR furnace/combustion chamber.
Lower total flow rate entering in the capture plant - CAPEXIncrease in CO2 concentration in the capture plant – CAPEX and OPEX
Previous work on using sequential combustion in thermal power plants with capture Gonzalez Díaz, Sanchez Fernandez, Gibbins, and Lucquiaud, M., (2016) Sequential supplementary firing in CCGT with PCC: A technology
option for Mexico for low-carbon electricity generation and EOR, Int J GHG Control: http://dx.doi.org/10.1016/j.ijggc.2016.06.007
Sanchez del Rio, Gibbins, Lucquiaud, (2017) On the retrofitting and repowering of coal power plants with post-combustion carbon capture: An advanced integration option with a gas turbine windbox, Int J GHG Control: http://dx.doi.org/10.1016/j.ijggc.2016.09.015
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Source: AirScience Technologies Inc. 2009
Source: CO2CRC
Natural Gas Natural Gas
AirPSA Tail Gas
Source: General Electric Company (GE)
Source: CB Energy Recovery
GT Flue Gas Steam
SMR Flue Gas
Flue Gas
GT SMR
HSRG PCC
• A purpose built SMR downstream of a H-class commercially available gas turbine • The SMR size is approx. three times the size of the largest commercially available SMR
CO2
CO2-depleted Gas
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SMR H2 plant downstream of a H-class Gas Turbine
H-class Gas Turbine SMR HSRG & Steam Turbines
O2 ≈ 11.3 vol%CO2 ≈ 4.5 vol%
O2 ≈ 1 vol%CO2 ≈ 15 vol%
Natural Gas
Air
Tail Gas
Hydrogen
Flue Gas to Capture PlantGT Exhaust flue gas
Natural Gas
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SMR H2 plant downstream of a H-class Gas Turbine
Steam methane reformer: Performance
Combustion of NG and tail gas in-duct burnersusing GT exhaust gas as oxygen source (instead of air)
Reforming reactions inside metallic tubes filled with nickel based catalystPre-reformerCnH2n+2 + n H2O → n CO + (2n+1) H2ReformerCH4 + H2O ↔ CO + 3 H2CO + H2O ↔ CO2 + H2
GT EFG (Integrated)
T (ºC) 631m (kg/s) 849%vol CO2 4.50%vol O2 11.26
Air (base case per SMR
T (ºC) 15m (kg/s) 104%vol CO2 0.04%vol O2 20.95
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SMR H2 plant downstream of a H-class Gas Turbine
H-class Gas Turbine SMR HSRG & Steam Turbines
Natural Gas
Air
Hydrogen
Flue Gas to Capture PlantGT Exhaust flue gas
Heat recovery to generate steam for the process
Heat recovery to generate steam for the steam turbines
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SMR H2 plant downstream of a H-class Gas Turbine
SMR furnace SMR Feed HX
Pre-reformer Feed HX
Sulphur absorber HX
Superheater
Flame temperature @ SMR furnace
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SMR H2 plant downstream of a H-class Gas Turbine
SMR H2 plant downstream of a H-class Gas Turbine
Assumptions & Constrains of the integrated system• GT Exhaust flue gas completely replaces combustion air in the furnace.• The purpose-built SMR is designed/sized to maintain:
• Reformer Equilibrium Temperature @ 910 ºC (same as in Base Case)• Oxygen excess @ 1 vol% (same as in Base Case)
• The same H2 production is possible by keeping the same Steam-to-Carbon ratio the pre-reformer and in the reformer.
Modifications on the SMR performance• A larger flow rate of GT exhaust flue gases at a higher temperature than the air stream (base case) is used for
combustion in the SMR furnace. The adiabatic flame temperature decreases from 1795 to 1568 ºC.• Change in the dominant heat transfer mechanism: Convective heat transfer becomes more significant than radiative
heat transfer -> 2nd Option: Convective Reformers.• Additional steam generation for power in the Heat Recovery Steam Generator.
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Results and key findings• A reduction of 30% in the flue gas flow rate feed to the
PCC plant and a CO2 conc. of 15 %vol, compared to 4.5vol% at the GT exhaust, leads to 20% reduction in theabsorber packing volume.
• The base case SMR absorber is redundant.• The net power output increases by ca. 11% (67 MWe).• 67MW of additional power is generated at a marginal
efficiency of 47.5% LHV with a ‘fully subsidised’ absorber.
Configuration Base Case Integrated
Performance parameters: SMR CCGT H-class GT + SMR + SC
H2 production (Nm3/h) 762,000 -- 767,000Power output (MWe) [1] 27.3 584.5 679.3NG feedstock (kg/s) 51 -- 51NG fuel (kg/s) 15 22 40Additional power output (MWe) -- -- 67
Capture plant: 2 x PCC Plants 1 x PCC PlantFlue gas flow rate (kg/s) 616 849 1,037CO2 conc (%vol) 18.9 4.5 15.1Absorber packing vol (m3) 11,146 11,690 18,850Number of absorbers 1 2 2[1] With Carbon capture and CO2 compression train
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SMR H2 plant downstream of a H-class Gas Turbine
Source: CO2CRC
Aeroderivative GT Convective reformer
PCC Source: General Electric Company (GE)
Source: CB Energy Recovery
HSRG
Source: Haldor & Topsoe
PSA Tail Gas
• A purpose built gas-heated reformer (convection heat transfer) downstream of a commercially available aeroderivative gas turbine engine.
• The reformer size is 50% larger than a commercially available gas-heated reformer
GT Flue Gas
SMR Flue Gas
Flue Gas
Steam
Natural Gas
Air CO2-depleted GasCO2
Gas-heated reformer (GHR) downstream of an aeroderivative Gas Turbine
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Performance of a Gas Heated Reformer
Combustion Chamber
Convection Section
Fuel: Tail Gas & Natural Gas or Tail Gas onlyO2 source: Air or GT Exhaust Flue Gas
Flue gas inlet (1270°C)
(600°C)(450°C)
(800°C)
Steam methane reforming
Air (Base Case)T (ºC) 100m (kg/s) 58.34%vol CO2 0.03%vol O2 20.74
GT EFG (Integrated)
T (ºC) 491m (kg/s) 148.05%vol CO2 3.37%vol O2 13.66
Flue gas outlet(600°C)
Flue gas outlet(600°C)
Gas-heated reformer (GHR) downstream of an aeroderivative Gas Turbine
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Aero-derivative Gas Turbine Gas Heated Reformer
HSRG & Steam Turbines
O2 ≈ 13.7 vol%CO2 ≈ 3.4 vol%
O2 ≈ 6.5 vol%CO2 ≈ 10.2 vol%
Natural Gas Hydrogen
Flue Gas to Capture Plant
AirPSA Tail Gas
GT Exhaust flue gas
Heat recovery to generate steam for the process
Heat recovery to generate steam for the steam turbines
Steamto Capture Plant
Natural Gas
Gas-heated reformer (GHR) downstream of an aeroderivative Gas Turbine
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GHR convection section
ReformerFeed HX NG Feed HX
Gas-heated reformer (GHR) downstream of an aeroderivative Gas Turbine
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Gas-heated reformer (GHR) downstream of an aeroderivative Gas Turbine
Assumptions & Constrains of the integrated system• Aeroderivative GT exhaust gas completely replaces the combustion air in the GHR combustion chamber• The GHR is sized in order to :
• Maintain reformer equilibrium temperature approach @ 350 ºC (Same as in Base Case)• Produce enough steam for the reboiler in the capture plant• The same H2 production is possible by keeping the same Steam-to-Carbon ratio in the reformer.
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Gas-heated reformer (GHR) downstream of an aeroderivative Gas Turbine
Configuration Base Case Integrated
Performance parameters: GHR CCGT Aero GT + GHR + SC
H2 production (Nm3/h) 73,558 -- 73,558Power output (MWe) [1] 57.3 71.5NG feedstock (kg/s) 5 -- 7NG fuel (kg/s) 0.2 2.9 2.9Additional power output (MWe) -- -- 14.2
Capture plant: 2 x PCC Plants 1 x PCC PlantFlue gas flow rate (kg/s) 71 148 162CO2 conc (%vol) 14.1 3.4 10.2Absorber packing vol (m3) 751 1,142 1,543Number of absorbers 1 1 1[1] With Carbon capture and CO2 compression train
Results and key findings• Reduction of 30% of the flue gas flow rate to the PCC
plant and a CO2 conc. of 10.2 %vol, compared to 3.4vol% at the aeroderivative GT exhaust, leads to 20%reduction in the absorber packing volume.
• The base case SMR absorber is redundant• The net power output increases by 25% (14.2 MWe)• 14.2MW of additional power is generated at a
marginal efficiency of 17%LHV with a ‘fullysubsidised’ absorber
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Results and key findings (summary)
Steam Methane Reformer (SMR) Gas Heated Reformer (GHR)
Configuration: H2 plant CCGT Integrated H2 plant CCGT Integrated
Performance parameter: 4x SMR H-class GT H-class GT + SMR
1x GHR Aero GT Aero GT + GHR
H2 production (Nm3/h) 762,000 -- 767,000 73,558 -- 73,558Power output [1] (MWe) 27.3 584.5 679.3 0 57.3 71.5Additional power output (MWe) -- -- 67.4 -- -- 14.2NG feedstock (kg/s) 51 -- 51 5 -- 7NG Fuel (kg/s) 15 22.2 40 0.2 2.9 2.9Net thermal eff (MWe/MWthNG) [1] -- 56.6 65.7 -- 42.9 53.5
Capture plant (MEA 30 wt%) 2 x PCC Plant 1 x PCC Plant 2 x PCC Plant 1 x PCC PlantFlue gas flow rate (kg/s) 616 849 1,037 71 148 162CO2 conc (%vol) 18.9 4.5 15.1 14.1 3.4 10.2Absorber packing vol (m3) 11,146 11,690 18,850 751 1,142 1,543Number of absorbers 1 2 2 1 1 1Note [1]: With CO2 capture and CO2 compressionSMR: Steam methane reformer; GHR: Gas heated reformer; GT: Gas Turbine;
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Key messages
• Reduction of number of absorbers could reduce capital costs
• No technical barriers identified. Larger conventional designs are needed.
• Effective thermodynamic integration allows
-Higher electricity production per unit of fuel at constant hydrogen output
-Higher hydrogen production per unit of fuel at constant power output
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Next Steps to develop the concept further
• Collaborative study with engineering contractors (gas turbine + SMR designers andoperators) focusing on
- Detailed capital costs and techno-economic analysis
- Feasibility study for large scale deployment
• Identify key factors with large effect on the short- and long-term variability indemand for both vectors
• Engineer flexibility in gas turbine, SMR and capture plant to cope with variabilityof output
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Mathieu Lucquiauda, Laura Herraiza, Hannah Chalmersa, Jon Gibbinsb
a School of Engineering, University of Edinburgh, The King’s Buildings, Edinburgh, EH9 3JL, UKb Department of Mechanical Engineering, University of Sheffield, Sheffield, S1 3JD, UK
UKCCSRC PROGRAMME CONFERENCE 4-5th September 2019, Edinburgh, UK
Integration Options for Low-Carbon Hydrogen and Power Synergies (WP AC4)
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