Mercury emissions control in two hazardous waste incineration plants with dry and semi-dry gas cleaning

Transcription

1 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 15 th Conference on Mercury Measurement and Control, Meliá Hotel, Düsseldorf Gestion des Déchets Spéciaux Agenda Cliquez et modifiez le titre 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

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/nm 3 db as daily average maximum) 4

3 Objectives 2 To test and validate the patented Bromine-enhanced mercury abatement technology (EP ) 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) CaBr 2 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

4 Some fundamental considerations (1/4) Chlorine-enhanced Hg-oxidation Relevant global reactions Thermodynamics Thermodynamics G as Free Reaction Enthalpy 4 HCl + O 2 2 H 2 O + 2 Cl 2 G G < < 00 SO 2 + Cl 2 + H 2 O SO HCl G G < 0< 0 SO 2 + 0,5 O 2 SO 3 G G < 0< 0 Hg + Cl 2 HgCl 2 G G < 0< 0 Chlorine less effective in Hg-oxidation because Cl 2 /Cl total << 1 SO 2 is consuming Cl 2 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 Relevant global reactions Thermodynamics Thermodynamics G as Free Reaction Enthalpy 4 HBr + O 2 2 H 2 O + 2 Br 2 G < 0 SO 2 + Br 2 + H 2 O SO HBr G > 0, 0, G < 0 SO 2 + 0,5 O 2 SO 3 G G < 0 < 0 Hg + Br 2 HgBr 2 G G < 0 < 0 Bromine highly effective in Hg-oxidation because Br 2 /Br total 1 SO 2 is not consuming Br 2 during boiler passage Source: Vosteen Consulting GmbH / VGB PowerTech, issue 3/2006, page 70 to 75 8

5 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 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/nm 3 db by continuous spiking) mass ratio Br/Hg Source: Vosteen Consulting GmbH / Diploma thesis R. Kanefke in

6 Mercury emissions control by dry APC HWI plant 1 with dry APC at a glance Rotary kiln with an annual capacity of tons per year HW waste - Solid Injection of activated carbon and lime - Pasty - Liquid Eau Emuls ion Echan ge chaleu r Rotary kiln Post-combustion chamber Boiler Quench Bagfilter Stack 12

7 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

8 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

9 Method at HWI plant 1 (1/5) Overview Mercury emission control tests Lime LHOIST SP AC NORIT GL50 Eau Emuls ion ICL CaBr 2 52% w. Echan ge chaleu r Hg-bombs / HgCl 2 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 Scientific TM 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 Downstream APC (stack) Analyser THERMO Hg Freedom SICK Mercem Measuring principle Advanced cold vapor atomic fluorescence Photometry, cold vapor atomic absorption Dilution rate No dilution HgT concentration range (µg/nm 3 db) (QAL1 : 0-45) Hg(0) / Hg(2+) speciation Yes No Detection limit (µg/nm 3 ) 1 < 1,5 Response time 1 minute 3 minutes 18

10 Method (3/5) Mercury spiking, injection of bromide and AC Mercury spiking into the rotary kiln Continuous injection of an aqueous HgCl 2 1% Hg w. From 500 to 3000 µg/nm 3 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 CaBr 2 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 Method (4/5) Burner arrangement and Hg injection at RK Head Photo 1 - Injection of HgCl 2 1% w. into the RK 20

11 Method (5/5) Injection of CaBr 2 and HgCl 2 Photo 1 - Injection of CaBr 2 52% w. into the PCC Photo 2 - Dosing pumps for CaBr 2 and HgCl 2 Photo 3 - CaBr 2 IBC and HgCl 2 container 21 Results (1/7) Reliable mercury measurements upstream APC (e.g. during spiking) Spiking at theorical 2000 µg/nm 3 db HgT concentration (µg/nm 3 db) 1750 Spiking at theorical 1000 µg/nm 3 db 1500 Spiking at theorical 500 µg/nm 3 db :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

12 Results (2/7) Reliable mercury measurements downstream APC (stack) SICK Mercem vs. NF EN Hg measurement standard (by certified laboratory APAVE) Before the mercury tests campaign (µg/nm 3 db) SICK Mercem NF EN ,9 7,0 After the mercury tests campaign (µg/nm 3 db) SICK Mercem NF EN ,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/nm 3 db) Hg removal efficiency : 90%, but it can be enlarged by bromide addition HgT concentration (µg/nm 3 db) Upstream APC Downstream APC Average Standard deviation Speciation Hg(2+) : 75% average Hg(0) : 25% average 24

13 Results (4/7) More is the mercury oxidized, more is the removal efficiency Filter temperature : 210 C HgT abatement efficiency (%) AC GL50 : 130 mg/nm3 db AC GL50 : 180 mg/nm3 db AC GL50 : 250 mg/nm3 db The AC GL50 flowrate is also important! Hg(2+) (%) 25 Results (5/7) Almost 100% Hg oxidation achieved with mass ratio Br/Hg > 300 Hg conc. upstream APC (µg/nm 3 db) Hg(0) Hg(2+) HgT HgT (Stack) HgCl2 1% Hg w. (1500 µg/nm 3 db th.) AC GL50 : 250 mg/nm 3 db ; Lime : 110 kg/h CaBr2 52% w. 2*7,5 l/h (Br/Hg = 200) CaBr2 52% w. 2*12,5 l/h (Br/Hg = 320) Hg conc. downstream APC (µg/nm 3 db) :30 08:40 08:50 09:00 09:10 09:20 09:30 09:40 09:50 10:00 10:10 10:20 10:30 Time (2014) 26

14 Results (6/7) Respect of the Hg ELV (50 µg/nm 3 db) with strong Hg spiking AC GL50 : 250 mg/nm 3 db ; Lime : 90 kg/h Stack HgT concentration (µg/nm 3 db) CaBr 2 52% w. 65 l/h HgCl 2 1% Hg w. (3000 µg/nm 3 db th.) Hg-bomb 25 g Hg-bomb 50 g Hg-bomb 100 g Hg-bomb 200 g STOP HgCl 2 STOP CaBr :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/nm 3 db Trials by injecting CaBr 2 52% w. in the PCC without Hg spiking (with certified laboratory LECES) => worst cases! AC GL50 : 250 mg/nm 3 db ; Lime: 140 kg/h CaBr 2 52% w. (l/h) Stack HgT (µg/nm 3 db) HBr (mg/nm 3 db) SO 2 (mg/nm 3 db) SO 3 (mg/nm 3 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

15 Mercury emissions control by semi-dry APC HWI plant 2 with semi-dry APC at a glance Rotary kiln with an annual capacity of tons per year Injection of activated carbon and lime HW waste - Solid Post-combustion chamber Boiler Quench (Spray Cooler) Bagfilter Droplet separator - Pasty Scrubber - Liquid Rotary kiln Stack Scrubber off-water is recycled to the spray cooler 30

16 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 CaBr 2 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

17 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 H 2 S 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 Preliminary results (1/2) Only CaBr 2 with strong Hg spiking : respect of the Hg ELV (50 µg/nm 3 db) AC GL50 : 260 mg/nm 3 db : Lime : 90 kg/h HgT stack concentration (µg/nm 3 db) CaBr2 52% w. 2*20 l/h Hg-bomb 100 g Hg-bomb 200 g CaBr2 52% w. 2*35 l/h Hg-bomb 300 g Hg-bomb 400 g STOP CaBr :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

18 Preliminary results (2/2) CaBr 2 & PRAVO with same strong Hg spiking : lower Hg stack values AC GL50 : 260 mg/nm 3 db : Lime : 130 kg/h HgT stack concentration (µg/nm 3 db) CaBr2 52% 2*20 l/h Pravo 1 l/h Hg-bomb 100 g Hg-bomb 200 g CaBr2 52% 2*35 l/h Hg-bomb 300 g Hg-bomb 400 g STOP CaBr2 STOP Pravo :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

19 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/nm 3 db) with strong Hg spiking Low HBr stack emissions (< 3 mg/nm 3 db) More efficient Hg emission control by dry APC with wet FGD at the tail-end ( semi-dry APC ) PRAVO 100 agent combined to CaBr 2 injection very promising To be confirmed in 2015 with continuous Hg spiking trials 37 Thanks for your attention! Titre de la présentation Sous-titre de la présentation