Mercury emissions control in two hazardous waste
incineration plants with dry and semi-dry gas cleaning
X. Chaucherie – Prof. Dr. B. W. Vosteen – P. Berg
April 15th, 2015 – VDI Wissensforum – 15th Conference on
Mercury Measurement and Control, Meliá Hotel, Düsseldorf
Gestion des Déchets Spéciaux
Agenda
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Objectives
Some fundamental considerations
Mercury emissions control with dry Air Pollution Control (APC)
HWI plant 1 at a glance
Method
Results from Hazardous Waste Incineration (HWI) plant 1
Mercury emissions control with semi-dry APC
HWI plant 2 at a glance
Method
What is PRAVO®100 agent?
Preliminary results from HWI plant 2
Conclusions and outlook
2
Objectives
Objectives 1
To get better understandings on mercury emissions control in HWI
plants with dry and semi-dry APC
Mercury monitoring upstream and downstream APC
Establishing reliable data on the mercury abatement efficiency
Total respect of the Emission Level Value (ELV) in France
(i.e. complying with 50 µg/Nm3 db as daily average maximum)
4
Objectives 2
To test and validate the patented Bromine-enhanced mercury
abatement technology (EP1386655) from Vosteen Consulting GmbH
Positive feedback from German HWI plants with wet APC (BAYER)
Dr. R. Kanefke: “Flexible and reliable low-cost technology”
Combination of high-temperature bromide injection into post-combustion
chamber and injection of “conventional” activated carbon upstream APC
Test-licence granted by Vosteen Consulting GmbH (with active support)
CaBr2 52% w. provided by ICL-IP free of charge
Precipitation agent PRAVO®100 provided by Vosteen Consulting GmbH
and its partner PAN Chemie Dr. Gábor Fülöp eK (for application at the
semi-dry APC)
5
Some fundamental considerations
Some fundamental considerations (1/4)
Chlorine-enhanced Hg-oxidation
Thermodynamics
Thermodynamics
Relevant global reactions
4 HCl + O2
SO2 + Cl2 + H2O
SO2 + 0,5 O2
Hg + Cl2
∆G as Free Reaction Enthalpy
2 H2O + 2 Cl2
SO3 + 2 HCl
SO3
HgCl2
∆G<<00
∆G
∆G∆G
< 0< 0
∆G∆G
< 0< 0
∆G∆G
< 0< 0
Chlorine less effective in Hg-oxidation because Cl2/Cltotal << 1
SO2 is consuming Cl2 already during boiler passage
Source: Vosteen Consulting GmbH / VGB PowerTech, issue 3/2006, page 70 to 75
7
Some fundamental considerations (2/4)
Bromine-enhanced Hg-oxidation
Thermodynamics
Thermodynamics
∆G as Free Reaction Enthalpy
Relevant global reactions
4 HBr + O2
SO2 + Br2 + H2O
SO2 + 0,5 O2
Hg + Br2
2 H2O + 2 Br2
SO3 + 2 HBr
SO3
HgBr2
∆G << 00
∆G
∆G
>
0,∆G
∆G<<00
∆G > 0,
∆G ∆G
< 0< 0
∆G ∆G
< 0< 0
Bromine highly effective in Hg-oxidation because Br2/Brtotal
SO2 is not consuming Br2 during boiler passage
1
Source: Vosteen Consulting GmbH / VGB PowerTech, issue 3/2006, page 70 to 75
8
Some fundamental considerations (3/4)
Mercury removal from flue gases
Source: Vosteen Consulting GmbH / Diploma thesis A. Pohontsch in 2000 and diploma
thesis R. Kanefke in 2002
9
Some fundamental considerations (4/4)
Influence of mass ratio Br/Hg on mercury removal efficiency η
at HWI Plant of BAYER / Currenta in Leverkusen-Bürrig
(raw gas mercury concentration 9600 µg/Nm3 db by continuous spiking)
mass ratio
Br/Hg
Source: Vosteen Consulting GmbH / Diploma thesis R. Kanefke in 2002
10
Mercury emissions control by dry APC
HWI plant 1 with dry APC at a glance
Rotary kiln with an annual capacity of 60 000 tons per year
HW waste
Injection of activated
carbon and lime
- Solid
- Pasty
- Liquid
Eau
Emuls
ion
Echan
ge
chaleu
r
Rotary kiln
Post-combustion
chamber
Boiler
Quench
Bagfilter
Stack
12
Details of HWI plant 1 (1/4)
Rotary kiln and its head
13
Details of HWI plant 1 (2/4)
Stack, quench and silo for slaked lime and AC
Stack,
60 m high
Quench:
Slender Nozzle Spray Cooler
Slaked Lime Ca(OH)2
AC (silo behind)
14
Details of HWI plant 1 (3/4)
Baghouse (pulse jet filter)
15
Details of HWI plant 1 (4/4)
Mercury Freedom System of Fisher ScientificTM
Continuous monitoring of the
mercury species
Hg(0), Hg(2+) and HgT
under harsh conditions
in the raw gas
upstream of the bagfilter
16
Method at HWI plant 1 (1/5)
Overview
Mercury emission control tests
Lime LHOIST SP®
AC NORIT GL50®
Eau
ICL CaBr2 52%
w.
Emuls
ion
Echan
ge
chaleu
r
Hg-bombs / HgCl2 1% Hg w.
Upstream APC
Hg(0) / Hg(2+) / HgT
Downstream APC
HgT
17
Method (2/5)
Hg monitoring systems
Continuous mercury monitoring systems
Slightly modified “Mercury Freedom System” for raw gas
measurements from Thermo ScientificTM
Specific measurement cycle configuration for harsh conditions
25-minutes measurement period followed by a 5-min “zero” period
3-hours calibration tests every 24 hours (zero and span-check)
Upstream APC
Analyser
Measuring principle
Downstream APC (stack)
THERMO Hg Freedom
SICK Mercem
Advanced cold vapor
atomic fluorescence
Photometry, cold vapor
atomic absorption
Dilution rate
40 - 80
No dilution
HgT concentration range
(µg/Nm3 db)
0 - 3000
0 - 250 (QAL1 : 0 - 45)
Hg(0) / Hg(2+) speciation
Yes
No
Detection limit (µg/Nm3)
Response time
1
< 1,5
1 minute
3 minutes
18
Method (3/5)
Mercury spiking, injection of bromide and AC
Mercury spiking into the rotary kiln
Continuous injection of an aqueous HgCl2 1% Hg w.
From 500 to 3000 µg/Nm3 db
Discontinuous injection of Hg-bombs
From 25 g to 200 g
Bromide injection and AC injection for mercury control
Injection into the post-combustion chamber of aqueous CaBr2 52% w.
Ratio Br / Hg up to > 400
Injection upstream the bagfilter of NORIT GL50® activated carbon
Conventional AC with positive feedback on dioxins abatement
400-hours test campaign in 2014 - 2015
19
Method (4/5)
Burner arrangement and Hg injection at RK Head
Photo 1 - Injection of HgCl2 1% w. into the RK
20
Method (5/5)
Injection of CaBr2 and HgCl2
Photo 1 - Injection of CaBr2 52% w. into the PCC
Photo 2 - Dosing pumps for CaBr2 and HgCl2
Photo 3 - CaBr2 IBC and HgCl2 container
21
Results (1/7)
Reliable mercury measurements upstream APC (e.g. during spiking)
2250
3
Spiking at theorical 2000 µg/Nm db
1750
3
Spiking at theorical 1000 µg/Nm db
3
HgT concentration (µg/Nm db)
2000
1500
3
Spiking at theorical 500 µg/Nm db
1250
1000
750
500
250
0
10:45
11:05
11:25
11:45
12:05
12:25
12:45
13:05
13:25
13:45
14:05
14:25
14:45
15:05
15:25
Time (2014)
22
Results (2/7)
Reliable mercury measurements downstream APC (stack)
SICK Mercem vs. NF EN 13211 Hg measurement standard (by
certified laboratory APAVE)
Before the mercury tests campaign (µg/Nm3 db)
SICK Mercem
NF EN 13211
7,9
7,0
After the mercury tests campaign (µg/Nm3 db)
SICK Mercem
NF EN 13211
15,9
14,0
23
Results (3/7)
During Hg measurements upstream & downstream APC
(normal operating conditions)
Different amounts of Hg in hazardous waste
Mainly ionic mercury upstream the bagfilter - even in case of
chlorinated waste only, but not always
Hg concentration at stack mainly below the ELV (50 µg/Nm3 db)
Hg removal efficiency : 90%, but it can be enlarged by bromide addition
HgT concentration (µg/Nm3 db)
Upstream APC
Downstream APC
Average
297
31
Standard deviation
187
18
Speciation
Hg(2+) : 75% average
Hg(0) : 25% average
24
Results (4/7)
More is the mercury oxidized, more is the removal efficiency
100
95
Filter temperature : 210°C
HgT abatement efficiency (%)
90
85
80
AC GL50 : 130 mg/Nm3 db
75
AC GL50 : 180 mg/Nm3 db
AC GL50 : 250 mg/Nm3 db
70
65
60
The AC GL50 flowrate is also important !
55
50
45
40
15
20
25
30
35
40
45
50
55
60
65
70
75
80
85
90
95
Hg(2+) (% )
25
Results (5/7)
Almost 100% Hg oxidation achieved with mass ratio Br/Hg > 300
3
Hg conc. upstream APC (µg/Nm db)
2000
1750
100
3
AC GL50 : 250 mg/Nm db ; Lime : 110 kg/h
90
CaBr2 52% w. 2*7,5 l/h
(Br/Hg = 200)
CaBr2 52% w. 2*12,5 l/h
(Br/Hg = 320)
80
70
1500
60
1250
3
HgCl2 1% Hg w. (1500 µg/Nm db th.)
50
1000
40
750
30
500
20
250
0
08:30
3
Hg(0)
Hg(2+)
HgT
HgT (Stack)
Hg conc. downstream APC (µg/Nm db)
2250
10
08:40
08:50
09:00
09:10
09:20
09:30
09:40
09:50
10:00
10:10
10:20
0
10:30
Time (2014)
26
Results (6/7)
Respect of the Hg ELV (50 µg/Nm3 db) with strong Hg spiking
50
3
AC GL50 : 250 mg/Nm db ; Lime : 90 kg/h
40
3
Stack HgT concentration (µg/Nm db)
45
35
CaBr2 52% w. 65 l/h
STOP CaBr2
30
Hg-bomb 100 g
Hg-bomb 200 g
25
HgCl2 1% Hg w. (3000 µg/Nm 3 db th.)
STOP HgCl2
20
Hg-bomb 25 g
Hg-bomb 50 g
15
10
5
0
13:30
14:00
14:30
15:00
15:30
16:00
16:30
17:00
17:30
18:00
18:30
19:00
Time (June 2014)
27
Results (7/7)
Low HBr emissions concentrations at stack: < 3 mg/Nm3 db
Trials by injecting CaBr2 52% w. in the PCC without Hg spiking (with
certified laboratory LECES) => worst cases !
AC GL50®: 250 mg/Nm3 db ; Lime: 140 kg/h
CaBr2 52% w.
(l/h)
Stack HgT
(µg/Nm3 db)
HBr
(mg/Nm3 db)
SO2
(mg/Nm3 db)
SO3
(mg/Nm3 db)
25
<5
0,6
17,3
0,05
25
<5
0,6
49
0,03
50
<5
0,7
19,6
0,03
50
<5
2,3
1,9
0,02
75
<5
2,8
30,6
0,03
75
<5
0,6
16,2
0,02
28
Mercury emissions control by semi-dry APC
HWI plant 2 with semi-dry APC at a glance
Rotary kiln with an annual capacity of 60 000 tons per year
Injection of activated carbon and lime
Post-combustion
chamber
HW waste
Boiler
Quench
(Spray Cooler)
Bagfilter
Droplet separator
- Solid
- Pasty
Scrubber
- Liquid
Rotary kiln
Stack
Scrubber off-water is recycled to the spray cooler
30
Details of HWI plant 2 (1/1)
Quench and scrubber
Quench (Rotary Spray Cooler)
Scrubber
31
Method at HWI plant 2 (1/2)
Continuous mercury emissions monitoring system
Only at stack : SICK MERCEM 300Z
Mercury spiking into the rotary kiln
Discontinuous injection of Hg-bombs
From 100 g up to 400 g
Mercury emissions control
Injection into the post-combustion chamber of aqueous CaBr2 52% w.
Ratio Br / Hg up to > 400
Injection upstream the bagfilter of NORIT GL50® activated carbon
Conventional AC with positive feedback on dioxins abatement
Injection of PRAVO®100 agent into the alkaline scrubber (pH = 7,5)
20-hours tests campaign in 2014
32
Method at HWI plant 2 (2/2)
What is PRAVO®100 agent?
PRAVO®100: inorganic alkaline Precipitation Agent of Vosteen
Consulting GmbH, produced by PAN Chemie Dr. Gábor Fülöp eK
(Germany)
Main compounds: sodium polysulfide, sodium thiosulfate, bromide and
sodium hydroxide
No relevant H2S development during applications at acidic and alkaline
scrubbers (TÜV measurements at WWT plant of Town Karslruhe and at
MSWI plant of HEAG Südhessische Energie AG in Darmstadt)
No aquatic toxicity: PRAVO oxidized by air into sulphur and sulphate
References :
BAYER/Currenta at its 4 rotary kiln HWI plants in Leverkusen-Bürrig, Dormagen and Uerdingen with wet
APC system applying PRAVO since 2004
Town Karlsruhe at its 2 stationary fluidized bed incinerators in the WWT plant Karlsruhe-Neureuth (sewage
sludge combustion) with wet APC system applying PRAVO since 2008
HEAG Südhessische Energie AG at its 3 municipal solid waste incinerators lines of HKW Darmstadt with wet
APC system applying PRAVO since 2008
Emschergenossenschaft Lippeverband (EGLV) at its 2 stationary fluidized bed incinerators in the WWT
plant Bottrop (sewage sludge combustion) with wet APC system applying PRAVO since 2013
33
Preliminary results (1/2)
Only CaBr2 with strong Hg spiking : respect of the Hg ELV (50 µg/Nm3 db)
100
3
AC GL50 : 260 mg/Nm db : Lime : 90 kg/h
80
3
HgT stack concentration (µg/Nm db)
90
70
60
CaBr2 52% w.
2*20 l/h
Hg-bomb
100 g
CaBr2 52% w.
2*35 l/h
Hg-bomb
200 g
STOP CaBr2
Hg-bomb
300 g
Hg-bomb
400 g
50
40
30
20
10
0
13:20
13:40
14:00
14:20
14:40
15:00
15:20
15:40
16:00
16:20
16:40
17:00
17:20
17:40
18:00
Time (2014)
34
Preliminary results (2/2)
CaBr2 & PRAVO® with same strong Hg spiking : lower Hg stack values
100
3
AC GL50 : 260 mg/Nm db : Lime : 130 kg/h
80
3
HgT stack concentration (µg/Nm db)
90
CaBr2 52%
2*20 l/h
CaBr2 52%
2*35 l/h
STOP CaBr2
STOP Pravo
70
Pravo 1 l/h
60
Hg-bomb
100 g
50
Hg-bomb
200 g
Hg-bomb
300 g
Hg-bomb
400 g
40
30
20
10
0
7:45
8:05
8:25
8:45
9:05
9:25
9:45 10:05 10:25 10:45 11:05 11:25 11:45 12:05 12:25 12:45 13:05 13:25 13:45 14:05
Time (2014)
35
Conclusions and outlook
Conclusions and outlook
More is the mercury oxidized, more is the removal efficiency
Up to 99,9% Hg removal efficiency with AC NORIT GL50®
With well-chosen AC mass flowrate
Almost 100% Hg oxidation achieved with mass ratio Br/Hg > 300
Efficient Hg emission control by dry APC only
Respect of the Hg ELV (50 µg/Nm3 db) with strong Hg spiking
Low HBr stack emissions (< 3 mg/Nm3 db)
More efficient Hg emission control by dry APC with wet FGD
at the tail-end (“semi-dry APC”)
PRAVO®100 agent combined to CaBr2 injection very promising
To be confirmed in 2015 with continuous Hg spiking trials
37
Thanks for your attention !
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