retrofitting study of a 350mw hard coal fired power plant
TRANSCRIPT
1
18.05.2009, CCT2009 Dresden
Retrofitting study of a 350MW hard coal fired power plant with post combustion capture
-optimal integration pathways for minimizing
the energy penalty
Christoph Kümmritz, Jochen Oexmann, Alfons Kather, Christian Mehrkens (1)Gerald Kinger, Martin Burböck (2)
(2)EVN AGEVN PlatzA-2344 Maria EnzersdorfAustria
(1)Technical university Hamburg-HarburgDenickestr. 15 D-21073 HamburgGermany
2
EVN: a short overview…1.5m electricity, gas, heat and watercustomers in Lower Austria
more than 3m customers in 18 countries
1.5m electricity customers in Bulgaria
700,000 electricity costumers in Macedonia
1,800MWe generation capacity (Gas, coal, hydro, wind and biomass)
124,000 km electricity network, 13,300 km gas pipelines
70 drinking/waste water plants for 10m people
Construction and operation of waste incineration plant in Moscow (Russia)
3
specific CO2 emissions of power stations decreased by 16% (1998-2008)
-
0,10
0,20
0,30
0,40
0,50
0,60
0,70
1998 2000 2002 2004 2006 2008 2010 zukünftig
Dur
chsc
hn. s
pez.
CO
2 Em
issi
on E
VN th
erm
. Kra
ftw
erke
Reduktion durch weitere Maßnahmen
1998 - 2008-16%
more than 32% of produced energy from renewable sources (2007/08)
minimizing power network losses energy-related advisory servicealternative fuels (ie. LNG)
CCS – bridging technology on the way to a carbon free energy production
3) increase end-use energy efficiency
1) increase in energy efficiency 2) renewable energy
development of water & wind power in EVN
CCS … Carbon Capture and Storage
CO2 emission – EVN's mitigation route
1 2 3 44) CCS technology
4
Carbon Capture & Storage
Pre-Combustion(IGGC)
Oxyfuel
Post-Combustion
air
air
air
nitrogen
nitrogen
oxygen
oxygen
*) ASU=air seperation unit
ASU *)
LZA *)
hydrogen
CO2
reforming
CO2
flue gas
CO2 scrubbing
CO2
steam turbine
steam turbinegas turbine
CO2
compressorcoal, natural gas
coal, natural gas
H2
coal,gas
CO
2st
orag
e
tran
spor
t sys
tem
(i.e
.: pi
pelin
e)
CO2
compressor
CO2
compressor
5
"Dürnrohr Block II"• commissioning: 1986• natural gas / coal • Output: 352 MWel
• flue gas cleaning:- SCR deNOx- desulfurization (semi-dry)- ESP filter
• fresh water cooling• Net-efficiency: (coal fire) ~42%• program for simulation: EBSILON Professional
Power station Dürnrohr
6
to water treatment
flue gas cooler
blower
absorber column
desorber column
heat exchanger
solvent pumps
fluegas cooler: better absorption at lower temp.
absorber column: chemical absorption of CO2
Rich / Lean HX: heat recovery
desorber column: (+Reboiler) expel CO2 by heat
set-up of post-combustion equipment
from FGD to CO2 compressor
steam and condensate from power plant
to atmosphere
solvent: Monoethanolamine (MEA)loading: 0.5 mol CO2/mol MEACO2-quality > 99.5%
7
integration of PCC equipment into the plant
generatorflue gas cleaning
absorberdesorber /reboiler
compressor
flue gas steam
CO2 CO2
cooling water
electrical energy
existing power plant
1.2. 3.
turbine
boiler
cooling water
steam (heat)
(new) PCC equipment
8
heat (steam)
steam extraction form intermediate pressure turbine:• existing turbine offers possibility to extract steam (originally
planned district heating system was not realized)
boundary conditions:• allowed steam velocity max. 85m/s (turbine)
• steam pressure lowered due to reduced mass flow
• Treb. @ 3,13 bar = 135°C losses due to long pipes; lower limit for optimal operation of reboiler (2,05 bar; Treb. =125°C)
• Treb. @ 1,9 bar = 115°C desorber operated at atmopheric condition (Treb. =105°C). Specific higher heat demand but lower steam parameters needed, more steam of this parameters and velocity available
capture rates from 30% to 67% possible
integration of PCC equipment (3)
A3A4A5A6
9
integration of PCC equipment (4)
for a 90% capture rate: 1) pipe from IP to LP turbine: not sufficient
amount of steam for heat demand of reboiler
2) steam before intermediate heating: need for rebuilding boiler to maintain cooling
3) steam after intermediate heating: parameters 42bar, 530 °Cneeded: ~3,5bar
HZÜ
KZÜ
2
3
IP
1
boiler
10
Reboiler
3,5 bar
MCO2 compressor
efficiency loss 10,0%specific energy demand: 0,339 kWhe /kgCO2
extra turbineand generator
… most promising variation:
drawbacks:additional turbine and generator needed, extensive reconstruction work needed.
existing plantretro-fit
11
0
1
2
3
4
5
6
7
8
20 30 40 50 60 70 80 90 100
effic
ienc
y lo
ss (%
)
CO2 capture rate (%)
maximum capture rate (IP steam): 67%specific energy demand:0,309 kWhe/kg CO2
energetically optimum: 43,5%specific energy demand:0,287 kWhe/kg CO2
Results – efficiency loss
CO2 capture rate 90%:efficiency loss 10,02%, specific energy demand: 0,339 kWhe/kgCO2
12
Results – specific CO2 emissions (kgCO2/MWhe)
0
100
200
300
400
500
600
700
800
900
without CCS 43,5%, energeticallyoptimum
67%, max. capturerate with IP steam
90% capture rate
efficiency:42%
efficiency:38%
efficiency:35%
efficiency:32%
specific CO2 Emissions of modern combined cycle power plant
13
economic effects – influence of CCS on CoE
CO2 capture rate (%)
+23%+25% +28%
+40%cost of CCS cost of CCS
specific cost of electricity without CCSspecific cost of electricity without CCSincreased cost due to reduced outputincreased cost due to reduced output
CoE … (specific) cost of electricity
14
economic effects – CO2 abatement costCO2 capture rate
43,5% 67% 90%CO2 abatement cost
(EUR)47,6 46,1 47,9
(2008)
15
conclusionssummary – results:
• steam from existing IP turbine: minimum reconstruction work needed• capture rates of 30 to 67% at -3 to -7% efficiency loss possible• steam from boiler after intermediate heating: additional turbine and
generator needed• capture rate of 90% at -10% efficiency loss possible
summary – economic results• increase in CoE: at 90% capture rate +40%• CO2 abatement cost: 46 - 48 EUR/t CO2
every project is different• comparison to literature (VGB power-tech study*): -13% efficiency loss;
CO2 abatement cost: 47 EUR (at 90% capture rate)• reasons for deviations: freshwater cooling, quality of coal (lower specific
emission)• for serious cost estimations all integration options have to be checked
*CO2-Capture and Storage – VGB Report on the State of the Art, 2004