Experience with straw firing in Danish combined heat and power plantsExperience with straw firing in Danish combined heat and power plants
KALEIDOSKOP BIOMASSE, ÖSTEREISCHE AKADEMIE DER WISSENSCHAFTEN, 9. NOVEMBER 2018
CARSTEN ERSKOV HENDRIKSEN NOVEMBER 2018
Ørsted 1 develops energy systems that are green, independent and economically viable
2
– ~5,900 employees
– Active in Scandinavia, United Kingdom, Germany, The Netherlands, USA and Taiwan
Major Shareholders: – Danish State 50.1% – Seas NVE 9.5% – Capital Group >5%
Wind Power Distribution & Customer Solutions
Bioenergy
– Global leader in offshore wind with 3.8GW installed
– Active in all parts of the value chain - develop, construct, own and operate offshore wind farms
– Significant and attractive build -out plan of 5GW towards 2022
– Ambition of 11 -12GW installed offshore wind capacity by 2025
– Largest power distributor in Denmark with 1 mill. customers
– Largest energy solutions provider in Denmark with 900,000 residential and industrial customers
– Developing green, innovative and cost efficient customer solutions
– #1 in Danish heat and power generation with 25% of market
– Converting heat and power plants from coal and gas to biomass
– Innovative waste -to -energy technology (Renescience)
– Energy storage solutions
Note 1 Ørsted was named DONG Energy A/S until 2017. DONG Energy A/S was a merger in 2006 of six Danish production and distribution companies of power, heat, oil and gas
Bioenergy will exit coal by 2023
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First major utility to fully exit coal
Put t ing furt he r a ct ion be hind Ø rst e d ’s vision o f le a d ing t he e ne rgy t ra nsfo rm a t ion
He a t cust om e rs support e a rly coa l pha se -out
Biomass conversions facilitate zero coal from 2023
Ø rst e d fue l consum pt ion (PJ)
66%
2016 2017 2023
Wa st e OilBiom a ss Na t ura l ga s Coa l
Background for straw firing in Denmark in combined heat and power plants
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CO 2-re duct ion in De nm a rk by re p la c ing coa l ba se d pow e r p roduct ion by w ind pow e r, b iom a ss a nd na t ura l ga s
Po lit ica l a g re e m e nt in 1993 t o ob liga t e pow e r p la nt s t o a pp ly 1 .4 m illion t ons o f b iom a ss (m a inly st ra w ) fo r pow e r p roduct ion in ye a r 2000
Lim it e d na t iona l a nd int e rna t iona l e xpe rie nce w it h st ra w com bust ion in 1993 La rge de ve lopm e nt p rog ra m fo r de ve lopm e nt a nd de m onst ra t ion o f st ra w
com bust ion t e chno logy init ia t e d O bliga t ion t o be fulfille d in 2008
Facts about Denmark
Non agricultural
Other crops
Forest Denmark 5 .8 m illio n inha b it a nt s To t a l a re a 4 3 .0 0 0 km 3 Fa rm la nd 2 6 .0 0 0 km 3 (6 2 %) St ra w co p s 1 4 .0 0 0 km 3 (4 0 %) St ra w p ro d uc t io n 5 .8 m illio n t o nne s St ra w fo r e ne rg y 1 ,6 m illio n t o nne s St ra w fo r e ne rg y 2 4 PJ
Land use
Straw utilization
So ur
ce : D
an m
ar ks
St at
is tik
, 2 01
< 1 % a ssum ing
- 1 b a le a p p ro x. 5 0 0 kg
- Tra nsp o rt a t io n b y t ruck, 2 4 b a le s p e r t ruck
- Ave ra g e d ist a nce fro m p ick-up a re a : 5 0 km
Facts about straw resources in Denmark
36%
0%
0,0
0,5
1,0
1,5
2,0
2,5
3,0
3,5
2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 2017
M io
to nn
es p
er y
ea r
Mio tonnes per year
Halmudbytte og halmanvendelse efter enhed, afgrøde, område, anvendelse og tid
Enhed: -
2006
2007
2008
2009
2010
2011
2012
2013
2014
2015
2016
2017
050
Mio tonnes per year
7
0,0
20,0
40,0
60,0
80,0
100,0
120,0
140,0
160,0
180,0
1990 1992 1994 1998 2000 2002 2004 2006 2008 2010 2012 2014 2016
PJ
Heat Pumps Waste Biogas Wood Straw Solar Wind
St ra w co nsum p t io n fo r e ne rg y p urp o se s incre a se d fro m 1 2 t o 2 4 PJ fro m 1 9 9 0 t o 2 0 1 6
Re ne w a b le co ve re d 2 5 % o f t he t o t a l e ne rg y co nsum p t io n in 2 0 1 6
Straw as fuel for power production
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Technical challenges: •low energy density – large volumes •potassium and chlorine
• slagging, fouling and corrosion • flue gas cleaning • utilization of residues
Handling of straw
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4 tonnes straw per hectare 500 kg big bales 24 bales on each truck
Overview of straw fired CHP plants in Denmark
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Plant Technology Commisioned Consumption Notes tonnes/year
Haslev CHP-plant Grate firing of straw 1989 26.000 Rudkøbing CHP-plant Grate firing of straw 1990 14.000 Slagelse CHP-plant Grate firing of straw 1990 30.000 Grenå CHP-plant CFB combustion of straw and coal 1992 40.000 Decommisioned Måbjerg bio boiler Grate firing of straw and wood 1993 65.000 Masnedø CHP-plant Grate firing of straw and wood 1996 45.000 Ensted bio boiler Grate firing of straw and wood 1998 150.000 Decommisioned Maribo-Sakskøbing CHP-plant Grate firing of straw 2000 45.000 Avedore unit 2 bio boiler Grate firing of straw 2001 150.000 Studstrupværket unit 4 Bio-dust co-firing of straw to coal 2002 10.000 Plant in reserve Amager CHP-plant unit 2 Bio-dust firing of straw and wood 2003 130.000 Plant in reserve Studstrupværket unit 3 Bio-dust co-firing of straw to coal 2005 30.000 From 2016 also wood pellets Fynsværket unit 9 Grate firing of straw 2009 150.000 Amager CHP-plant unit 1 Bio-dust firing of straw and wood 2009 350.000 Currently wood pellets Affald Varme Århus Grate firing of straw 2016 230.000
No t e s Plants in Bold text: Co nst ruct e d a nd /o r o p e ra t e d b y Ø rst e d /DO NG Ene rg y A/S o r m e rg ing co m p a nie s
Sheet1
Plant
Technology
Commisioned
Consumption
Notes
tonnes/year
1992
40,000
Decommisioned
1993
65,000
1996
45,000
1998
150,000
Decommisioned
Grate firing of straw
2002
10,000
2003
130,000
2005
30,000
Fynsværket unit 9
2009
350,000
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Bio dust firing – 2 plants co -firing of straw to coal plants and 2 plants co -firing of straw and wood pellets
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13
Co-firing of straw and coal in fluidized bed – 1 plant
Straw fired (grate) boilers
Learning elements from the small scale CHP plants
• Loca l fue l (m a x. 100 km ), He sst on ba le s ( st a nda rd size ) • Ma x. 2 da ys st o ra ge a t p la nt • Cra ne (m e a sure w e ight a nd m o ist ure cont e nt ) • Scre dde r syst e m a nd bo ile r scre w fe e de r • Boile r de sign
• Sla g • Sla gg ing supe rhe a t e r • Re duce t e m p . be fo re conve ct ive pa rt
• High t e m pe ra t ure co rro sion • Se le c t ion o f m a t e ria ls • Addit ive s (no t use d )
• Low t e m pe ra t ure co rro sion • Ash ut iliza t ion
• Bot t om a sh (80%) re cycle d t o fa rm la nd but fly a sh (20%) ca nno t be re cycle d due t o t he ca dm ium cont e nt
• NO x conside ra t ions • Lim it e d e xpe rie nce w it h SCR/SNCR, one p la nt w it h low dust SCR is t a ke n
int o ope ra t ion in 2016
Superheater design allowing slagging operation
Air pre he a t e r Dist ric t he a t ing flue ga s coo le r
Challenge with cold end corrosion for straw fired boiler
Conclusion – experience with straw firing in Danish CHP
Resources
There is a surplus of approx. 2 million tons straw per year. However, distance to source and yearly variation in yield might limit further growth in straw fired capacity in Denmark
Main technologies
– co-firing of straw in pulverized coal -fired power plants:
– approx. 15 % is possible if high -dust SCR deNOx technology is applied
– approx. 50% is possible i CFB technology is applied
– pulverized fired boilers: 100% straw is possible, if straw is processed in hammer mills for pellets or direct firing. However, 100% straw firing requires either SNCR or low dust SCR and a suitable boiler design for slagging operation of the superheaters
Challenges
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Experience with straw firing in Danish combined heat and power plants
Ørsted1 develops energy systems that are green, independent and economically viable
Bioenergy will exit coal by 2023
Background for straw firing in Denmark in combined heat and power plants
Facts about Denmark
Renewable energy production in Denmark
Straw as fuel for power production
Handling of straw
Grate firing of straw – 10 plants
Bio dust firing – 2 plants co-firing of straw to coal plants and 2 plants co-firing of straw and wood pellets
Co-firing of straw and coal in fluidized bed – 1 plant
Learning elements from the small scale CHP plants
Superheater design allowing slagging operation
Foliennummer 16
Biomass publication available