THE 12th EUROPEAN GASIFICATION CONFERENCE March 10–13, 2014 Rotterdam, The Netherlands
Vaskiluoto CFB Gasificaton Plant
Juhani Isaksson, Valmet Power
2
12 March, 2014 © Valmet | Author / Title 3
Valmet Power - gasification offering
4
Product gas for
industrial kilns
• Sawdust, forest
residues, fresh wood,
bark
• 20 – 80 MWfuel units
• Typically includes a
dryer
• Dusty product gas
• Also other types of
kilns possible
Product gas for
power boilers
• Woody biomass,
bark, peat, straw…
• Superior electricity
efficiency
• (Existing) power
boilers
• 50 – 300 MWfuel
units
• Typically includes a
dryer
• (Gas filtering)
Product gas from
waste for power
production
• Waste-derived fuel
• High electricity
efficiency
• Typically a new gas
boiler
• Gas filtering -> clean
product gas
• 50 – 100 MWfuel units
or multiple units
connected to a boiler
Indirect
gasification of
biofuels
• Suitable for clean
biofuels
•Suitable for cases
HIGH HEATING VALUE
GAS is needed 8 SNG,
refinery feed motors)
Cofiring is an efficient way to use biomass
Example:100 MW of biofuel available at the district
5
100 MW, fuel Small boiler,
efficiency 25 % 25 MW
green electricity
100 MW, fuel Large boiler,
efficiency 40 % 40 MW
green electricity
+
160 MW
coal electricity 400 MW coal
The final outcome is 60 %
more green electricity !
Valmet scope in Vaskiluodon Voima’s gasification project
Full scope services with total plant optimization
– Fuel receiving and handling
– Drying
– Gasification
– Boiler modifications
– Automation, electrification and instrumentation
Wet biomass
Existing PC boiler
Instrumentation,
electrification
and automation
Biomass receiving
and pre-handling Large-scale belt dryer CFB gasifier
140 MWfuel
Product gas
Dried biomass
VASKILUOTO GASIFICATION PLANT
Date Author Title INTERNAL 7
FUEL STORAGE
AND HANDLING
PC BOILER
CFB
GASIFIER
DRYER
Valmet CFB gasifier
CFB Gasifier
Size 20 – 140 (300) MWth
Fuel Biomass, waste
Gasification media Air
Operating
temperature
750 – 900 C
Operating pressure 5-30 kPa(g)
Product gas
heating value
3-7 MJ/nm3 (LHV)
8
Fuel feeding CFB reactor
Bottom ash removal
Cyclone
Product gas line
Product gas/
gasification air
- heat exchanger
Biomass dryer Vaskiluodon Voima
Vaasa, Finland
9
Start-up 2012
Process Gasification (140 MW)
Materal Forest resudues (chips)
Size 274 m2 / 2 950 ft2
Layer type Single
Heat source Water/glycol-50%
73 - 85°C / 163 - 185°F
Capacity 10 metric tons/h
of evaporated water
Fuel Moisture vs. Gasifier output
Fuel moisture ( waste ) 20% 30% 40%
Gasifier max output 100 89 77
Waste fuel: HHV dry 22,5 MJ/kg, Ash 7,6%
CFB gasifier
Date Author Title 10
0
1
2
3
4
5
6
7
8
20 40
Ga
s h
ea
t va
lue
ho
t M
J/m
3n
Fuel Moisture
Gas heat value MJ/m3n hot ( incl. sensible heat )
Vaskiluoto Biomass Gasification plant
and the main experiences of the project
11.3.2013
Matti Tiilikka
Project manager
Vaskiluodon Voima Oy 11
Vaskiluoto 2
Investments:
‒ Boiler plant 1982
‒ Desulphurization plant 1993
‒ New turbine plant 1998
In technical terms, the plant is
fit for use until 2030
Main figures:
‒ Electricity output 230 MW
‒ District heat output 175 MW
Vaskiluodon Voima Oy 12
Vaskiluoto Power Plant
Main project drivers
Main drivers for the project:
To replace large amount (25-40%) of coal with renewable CO2-neutral fuel.
‒ The gasification plant will be run on full capacity and coal firing will be
reduced on boiler part loads.
To extend the lifetime of the existing power plant unit
To achieve capability to use multiple fuels (fuel cost optimization)
To guarantee a cost-effective district heating solution
Investment cost and benefits
Total investment cost 40 M€. State investment subsidy 10,8 M€
(Ministry of Employment and the Economy)
Cost savings:
‒ Reduction of CO2-emission cost, reduction of CO2-emissions
up to 230 000 t/yr.
‒ Feed-in tariffs of renewable energy
‒ Reduction of the environmental taxes of district heating
Other benefits:
‒ Low total cost compared with the construction of a totally new biofuel
power plant
‒ Gasification compared with wood pellet firing: higher cost of pellet
production (around +50%) and pellet milling is avoided
‒ Local fuels - Positive effects to the local economy, 15 M€/a.
• The new activities will employ 100 people in fuel logistics
Vaskiluodon Voima Oy 14
Project implementation
Main Schedule
Environmental permit 10.8.2010
Binding promise of the investment subsidy 8.4.2011
Contract with Metso Power Oy 6.5.2011
Start of the foundation work 1.9.2011 (4 months)
Start of the equipment installation 1.4.2012 (11 months)
Planned five weeks’ outage in August 2012 (15 months)
Start of test runs October 2012 (17 months)
Start of the commercial use January 2013 (20 months)
Vaskiluodon Voima Oy
Project experiences
Total project costs did stay in the frames of the budget
Installation time:
‒ The time schedule was very tight. That pressed final installation work
to late autumn and made the test running period quite challenging.
‒ Even so, the boiler modifications were made as planned during
5 weeks’ outage.
‒ The site safety was organised fine and there was only one minor
accident on site.
Test run:
‒ Only minor effects on PC-boiler operation, no boiler trips – great!
‒ The fuel unloading pockets were designed with high separating walls and
some types of trucks have had difficulties to operate between those walls.
‒ In the fuel sampling system there has been jamming with wet and cold peat.
‒ Temperature differences on the body material of air heaters have caused
distortion and damaged bellows of the gas ducts.
16 Vaskiluodon Voima Oy
Operation experiences
There has been no instabilities in the boiler evaporator.
NOx -emission level has been under the limits of environmental permit
(500 mg/m3(n)) – after the modification the emission level is around 350
mg/m3 and has been around 400 mg/m3 last year.
The warranty values are likely to be fulfilled. Warranty tests will be
carried out in March 2013.
The dyer has functioned fine. We have seen that investment quite
successful also because biofuels have been abnormal wet this year.
The potential risk of the hot corrosion of the superheaters was noticed
and therefore a theoretical study was made by Metso. As a result it was
decided to keep the rate of biofuel always under the rate of coal.
17 Vaskiluodon Voima Oy
12 March, 2014 © Valmet | Author / Title 18
Gasifier load
(70 – 132 MW)
Live steam pressure
Temperature and flow
Load following with coal
Reduction for nights
NOx content of boiler flue gases
12 March, 2014 © Valmet | Author / Title 19
200
225
250
275
300
325
350
375
400
425
450
0 % 10 % 20 % 30 % 40 % 50 % 60 %
NO
x m
g/N
m3 6
% O
2
Gasifier share of total fuel input
High O2 Low O2
SO2 content - before sulphur removal
12 March, 2014 © Valmet | Author / Title 20
0
50
100
150
200
250
300
350
400
450
500
550
5 % 10 % 15 % 20 % 25 % 30 % 35 % 40 % 45 % 50 % 55 %
SO
2
m
g/N
m3 6
% O
2
Gasifier share of total
First year availability
12 March, 2014 © Valmet | Author / Title 21
0.0 % 20.0 % 40.0 % 60.0 %
Fuel handling
Flame detection
Burner impeller damage
Air preheater imbalance
Air damper leakage
Torch test mailfunction
Distribution of causes for unavailability (total 3 %)
First operational year 2013/2014 availability was 97 %
Dryer (Titanic)
We are very pleased about the final results of this project and like to thank all
our suppliers for the fine co-operation!
22 Vaskiluodon Voima Oy
For further information contact: [email protected]