HCl Removal in the Presence of SO2 Using

Dry Sodium Sorbent Injection

Yougen Kong, Mike Wood

Solvay Chemicals Inc.

Houston, Texas
Dry Sodium Sorbent Injection

Proven results - Again

The recent EPA proposals for controlling HAPs,

specifically HCl, has raised questions regarding 

efficacy of sodium DSI systems to treat high lev

in the presence of SO2.

Seeing the need for reliable data, Solvay Chemic

SOLVAir Solutions group contracted a series of to model coal fired power plants using moderate 

coal with high levels of chlorides.

As expected, sodium sorbents were easily able 

compliance even with the tightest emissions lim
Test at EERC, University of North Dakota

 A pilot plant Central Appalachian Coal

(CAPP)

Two PM control devices

ESPBag house

Four sodium sorbents and one

hydrated lime

Flue gas duct diameter: 6” The

small duct size allows excellent

mixing between sorbent and flue

gas, and consequently may result

in better efficiencies than may be

experienced in field applications.
CAPP Coal Analyses

Chlorine, μg/g 954–970Heat Value, Btu/lb 11,496

Ash 11.28 11.85

Oxygen (Ind) 10.05 8.48

Sulfur (%) 0.78 0.78Nitrogen 1.22 1.22Carbon 71.63 72.63

Hydrogen 5.04 5.05

Ultimate Analysis, as received, %

Ash 11.29 11.85Fixed Carbon 52.16 52.26Volatile Matter 33.76 33.24Moisture 2.79 2.64

Proximate Analysis, as received,% Sample 1 Sample 2
Sorbents

Trona (S200)

d50: 30 μm, d90: 125 μm

Milled Trona (S250)

d50: 15 μm, d90: 60 μm

Milled Sodium Bicarbonate (S350)

d50: 12 μm, d90: 40 μm

Finely Milled Sodium Bicarbonate (S450

d50: 7 μm ,d90: 17 μm

Hydrated Lime

d90: 45 μm, purity: 96.8%
Injection Upstream of ESP















	

 


 °

   

  

Residence Time: ~ 2.5 seconds
Injection Upstream of Baghouse











	

 


 "°

   

  

• Residence Time in duct: ~ 1 second

• Baghouse was cleaned before each run
Sorbent Performance

HCl Removal
0.00010.0010

0.01000.1000

0.0 0.2 0.4 0.6 0.8 1.0 1.2 

Total NSR

HClatStack(lb/mmBtu)

S200 S250 S350 S450

HCl Removal with Sorbent Injected at ES

Utility MACT Limi

Boiler MACT Lim
0.00010.0010

0.01000.1000

0 0.2 0.4 0.6 0.8 1 1.2 1.4 

Total NSR

HClatStack(lb/mmBtu)

S200 S250 S350 Hydrated Lime

HCl Removal with Sorbent Injected at Bagho

Utility MACT LimiBoiler MACT Lim
Sorbent Performance

Some SO2 is unavoidably removed coinc

with the removal of HCl. Higher reactivity 

HCl than SO2 would suggest lower levels 

removal
SO2 Removal with Sorbent Injected at ESP 

0

0.20.40.60.8

1

1.2

1.41.6

0 0.2 0.4 0.6 0.8 1 1.2 

Total NSR

SO

2

atStack(lb/mmBtu)

S200 S250 S350 S450
SO2 Removal with Sorbent Injected at Bagh

0

0.20.40.60.8

1

1.21.4

0 0.2 0.4 0.6 0.8 1 1.2 1.4 

Total NSR

SO

2

atStack(lb/mmBtu)

S200 S250 S350 Hydrated Lime
Sorbent Performance

Combined HCl and SO2 results
HCl Removal vs. SO2 Removal - ESP

0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%

0% 10% 20% 30% 40% 50% 60% 70% 80% 90% 

SO2 Removal Rate (%)

HClRemovalRate(%)

S200 S250 S350 S450
HCl Removal vs. SO2 Removal - Baghous

0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%

0% 10% 20% 30% 40% 50% 60% 70% 80% 9

SO2 Removal Rate (%)

HClRemovalRate(%)

S200 S250 S350
Summary

 Dry Sodium Sorbent Injection using trona or sodium

bicarbonate is a cost effective way to mitigate HCl, SO2 

Low capital cost.Small footprintShort installation timeCompatible with ESP and Baghouses.

 Able to achieve high removal rates for HCl (>99%) an(>90%)

Able to meet the HCl limit in both the proposed Utility MACT 

lb/MMBtu) and the Industrial Boiler MACT (0.022 lb/MMBtu)

 Effective over a wide temperature range (275 0F – 150 Has been implemented at hundreds of sites in the Un

States and Europe including industrial sites, waste inc

and coal-fired power plants.