SECTION VII: EFFICIENT WASTE-TO-ENERGY “Increase of power plant efficiency by using best available FGC - technologies” by Mr. Bernd Morun, Director General of DrySo Tec Consult, Germany

1. Increase of power plant
efficiency by using best
available FGC- technologies
Dr. B. Morun
DrySoTec
Table of contents:
1.: clean gas values for MWI- plants and “how to reach it”
2.: criteria for BAT (best available technology) and energy efficiency
3.: comparison of different FGC- technologies
4.: practical experience / results with dry absorption plants
- changing wet scrubber technology to dry absorption
- changing semi-wet system to dry absorption
- optimized dry- system for city- heating
- desulphurisation in an industrial plant
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2. Abstract of the 17.BImSchV (D) ; EU Guideline 2000/76/EG
Clean gas values for FGC- relevant components:
DAV HHAV
HCl: < 10 mg/Nm3,dry < 60 mg/Nm3,dry
SO2: < 50 mg/Nm3,dry < 200 mg/Nm3,dry
HF: < 1 mg/Nm3,dry < 4 mg/Nm3,dry
Hg: < 30 µg/Nm 3,dry < 50 µg/Nm3,dry
NOx: < 200 mg/Nm3,dry < 10 mg/Nm3,dry
Dust: < 10 mg/Nm3,dry < 30 mg/Nm3,dry
Cd/Tl: < 0,05 mg/Nm3,dry*
PCDD/-DF: < 0,1 ng/Nm3,dry*
TOC: < 10 mg/Nm3,dry
DAV: Daily average value
HHAV: Half hourly average value
*) for each measurement period
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Raw gas values and necessary absorption rates
17. BImSchV for acid components:
HCl SO2 HF
DAV HHAV DAV HHAV DAV HHAV
< 10 < 60 < 50 < 200 <1 <4 m g/Nm 3,tr
Raw gas Necessary minimum-
HCl absorption rate (%) (DAV)
1000 99,00
2000 99,50
3000 99,67
4000 99,75
SO2
300 83,33
600 91,67
1000 95,00
1500 96,67
2000 97,50
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3. Basic techniques currently used for flue gas cleaning:
- wet flue gas cleaning
- semi-wet scrubber
- (conditioned) dry absorption
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Flue gas cleaning in a waste incineration plant with wet cleaning:
Gasburner SCR- cat
Fixed bed
coke filter
Quench
Lime HCl- and SO2- scrubber Heat exchanger
Spray dryer Fabric filter Booster fan ID fan
(Each m3 water input for conditioning leads to appr. 800 KW loss in heat)
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4. Flue gas cleaning with a semi wet system (and additional additive)
17.BIm SchV
Milk of lime /
w ater
Furnace
Kessel Sprü
Spr üh-
absorber GWF
Spray-
Spray-
absorption
Filter
SCR
NH4OH
Activated
additional coke
Kakmilch/
Kakmilch/ Additiv Residue
HOK
(Each m3 water input for conditioning leads to appr. 800 KW loss in heat)
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Conditioned dry absorption system with lime:
Ca(OH)2
Water powder
ID- fan
Emission
Source Reactor
to Stack
Filter
Recirculation
Residue
(Each m3 water input for conditioning leads to appr. 800 KW loss in heat)
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5. (New) Simple dry flue gas cleaning with NaHCO3:
NaHCO3 Activated
Carbon
Fan Fabric
filter
Mill
(red.)
Emission source
ID-
Fan
Heat
Residue exchanger
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Today important:
Clean gas values and energy effiency in accordance with RL2008/98/EG
Since 2007/08: approx. 50 % of the new builded incineration plants in
Germany have a “simple” dry FGC- system* using NaHCO3, activated
coke and an optimized energy recovery.
Examples: - HKW Blumenthal, Bremen
- Continental Korbach
- TVR Schwarza, Schwarza
- EBS Bernburg, Bernburg
- EVI Emlichheim, Emlichheim
- TREA Gießen, Gießen
- EVA Harmuth, Essen
- MVV Gersthofen
…….
*) because each m3 water input for conditioning leads to appr. 800 KW loss in heat
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6. Criteria for finding the best available technology (BAT)
Absorption rate
Operating costs System- availability / -security
(Energy, Personnel, M&I…)
Behavior at pollutant peaks/
Residue disposal costs BAT suddently changing flue gas
Additive supply costs Investment costs
Regulation action
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Known absorption rates with different techniques:
Technique: Wet Spray- MKT- Conditioned Total dry
absorption system dry-absorption** (Bicar)
Additiv: CaO CaO CaO/Ca(OH)2 Ca(OH)2 NaHCO3
typical HCL >99 ~98 >99 >98 >99
absorption rate (%):
SO2 ~90 ~75 ~85 ~70 >95
stöchiom. ratio: ~1,1 ~2,2 ~2,0 >2,3 ~1,2
(Additiv/(HCl+SO2))
Heavy metals and organic Emissions are adsorbed with high efficiency by blowing in
activated carbon powder. This point is here not further discussed.
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7. Advantages and disadvantages of different techniques:
Technique: wet Spray- MKT-System (cond.) Dry- Total dry
absorption absorption (Bicar)
Additiv: CaO CaO CaO/Ca(OH)2 Ca(OH)2 NaHCO3
Behavior at pollutant (-) (---) (++) (+) (+++)
peaks:
Additiv supply costs: (+++) (++) (-) (-) (--)
Residue disposal costs: (++) (--) (-) (--) (++)
Space requirements: (---) (--) (--) (++) (++)
Handling milk of lime: yes yes yes no no
Investment costs: (---) (--) (--) (+++) (++)
Availability: (+-) (+-) (+) (+++) (+++)
Operating costs: (---) (--) (--) (++) (++)
Regulation action: (+-) (-) (++) (++) (+++)
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Absorption rate vs. Stöchiometric ratio in comparision
Abscheideverhalten verschiedener Additive
of different additives:
gegenüber SO und HCl 2
NaHCO3 Ca(OH)2
fürHCl
für SO2 für SO2
f ür HCl special lime SP
neue HSH
100
90 al te HSH
special lime A
80
70
Normal lime
Normal hydrat
60
50
40
30
20
10
0
0 1 2 3 4 5 6 7
Stoechiometric ratio
StöchiometrischesVerhältnis (stöch.Molzahl Additiv / SO2)
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8. Examples related to practice; increasing of energy- efficiency
by changing the FGC- system
A) Conversion of a wet system to a total dry system
Picture: (old) FGC- system of the MVA Weisweiler
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MVA Weisweiler (3 Lines for 16t Waste/h each)
Raw gas values (acids):
HCl: 900 bis max. 3.000 mg/Nm3
SO2: 350 bis max. 1.000 mg/Nm3
HF: 30 bis max. 40 mg/Nm3
Vol.- stream: 76.000 Nm3/h,tr
Cleangas values:
Wet system: Dry system:
HCl: << 5 mg/Nm3 HCl: << 5 mg/Nm3
SO2: << 5 mg/Nm3 SO2: << 5 mg/Nm3
HF: < 1 mg/Nm3 HF: < 1 mg/Nm3
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9. Picture: New FGC- system of the MVA Weisweiler
(Line 1 since 06.2010 in oparation; L 2 since Februar 2011; L 3 starting April 2011)
The clean gas values are the same as with 2 stage wet scrubber before
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Expected energy savings for all three lines in comparison to the wet
system (validated for the first line started june 2010; 2. line is running since
February 2011; 3. line starts at this moment):
- electrical energy consumption: ca. 15.000 MWh/a = minus 48 %
- Use of natural gas: ca. 54.000 MWh/a = minus 97 %
- steam consumption/
expanded use of flue gas heat: ca. 31.000 MWh/a = minus 84 %
(without additional benefits for less maintenance and lower personal costs)
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10. B) Conversion of a semi wet system to a dry FGC- system:
MHKW Rosenheim:
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B) Conversion of a semi wet system to a dry FGC- system:
Picture: MHKW Rosenheim; old FGC- system (until 2009)
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11. Picture: MHKW Rosenheim with NaHCO3- FGC- system and
additional use of flue gas heat (after 2008)
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After conversion founded:
- 10% increase of burned waste because the (old) Bottleneck
FGC- system was not further given
- > 2 MWh/h expanded use of flue gas heat (and the possibility of more in
future by using the rest- heat in cleangas (160 110 °C) if necessary
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12. MHKW Rosenheim; comparison of running costs semi wet / dry:*
Difference
milk of lime
system
CaO NaHCO3
Running costs (only) (semi
2008 2009
wet)to
NaHCO3
(dry)
Costs for additive € 188.000 308.329 120.329
Costs for residues € 353.000 181.975 -171.025
Costs for electr. Power € 50.200 23.400 -26.800
Costs for spare parts € 25.000 5.000 -20.000
Maintenance & Repair € 50.000 5.000 -45.000
Total costs € 666.200 523.704 -142.496
(Without additional benefits for the plus of heat energy (2 MW))
*) linearisized for direct comparison
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C) RPF- plant with optimized energy- output: TREA Gießen
Basic data:
Volume stream: appr. 22 - 25.000 Nm3/h
Temperature in Filter: appr. 165 °C
HCl (raw gas): appr. 2.300 mg/Nm3
SO2 (raw gas): appr. 800 mg/Nm3
HCl (clean gas): under limit of detection
SO2 (clean gas): ca. 1 - 10 mg/Nm3
RPF: ca. 3 t RPF/h
Pure production of district heating
Coverage of appr. 12 % of the complete district heating
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13. C) RPF- plant with optimized use of energy: TREA Gießen
Principle FGC- system:
Residue
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TREA Gießen; Wirkungsgrad
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14. D: Example of industrial desulfurization: Lead- Factory
In this case: Two possibilities of dry sorption are tested:
Dry sorption with special hydrated lime (> 40 m2/g)
A) Dry sorption with NaHCO3
Constellation:
Air / dust from
production- room
Additives
T = 40 - 60°C
ID- fan
T > 150 °C
T ~ 50 °C
Oven Fabric filter
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Comparison between different additives
900
SO2 without additives
800 SO2 with 104 kg/h Sorbacal
SO2 with 40 kg/h NaHCO3
SO2 in stack (mg/Nm³)
700
600
500
400
300
200
100
0
0 50 100 150 200 250 300 350 400
Time (min)
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15. Are the important points for BAT fulfilled with the total dry NaHCO3- system?
Energy efficiency of the FGC
Absorption rate
Operating costs
(Energy, Personnel, M&I…) System - availability / -security
Behavior at pollutant peaks/
Residue disposal costs suddently changing flue gas
BAT
Additive supply costs Investment costs
Regulation action
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Thanks for your attention !
DrySoTec contact in Spain:
ingeniería del P.A.E. Ibarrabarri, edif. A1
GORCO medio ambiente 48940 LEIOA (Vizcaya)
944635244 / 944801223
gorco@gorco.es
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