Lhoist North America

Cement Industry Experience

DSI for Acid Gas Control

October 5, 2011
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Sorbacal® Product Development

Emission Control Hydrates

• From a standard hydrate to a high performance 

hydrated lime

 Standard hydrated lime

 Sorbacal® H: First generation emission control hydrated lime

 Sorbacal® SP/SPS: Next generation - high pore volume and 

high specific surface area hydrated lime

• The decisive parameters to enhance the gas/solid 

contact are Pore Volume and Specific Surface 

Area of the reagent
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Sorbacal® –

A Widespread Product

Municipal and hospital solid waste 

incineration

Industrial waste incineration

HCl

SO2

SO2

HF

HCl

Sludge incineration

SO2 HCl

SO3 plume in Power plants

SO3

Brick and tile factories, cement plants, 

Glass industry, Non ferrous metals ...

SO2

HCl

HF
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Standard Hydrate

• Physical characteristics

 Surface 14 – 18 m2/g (BET)

• Reaction depending on temperature and humidity

• Disadvantage: Difficult to achieve high 

performance for certain applications

• Physical characteristics

 Finer particles and high surface area

 Surface > 20 m2/g (BET)

Sorbacal® H

Range of Products
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Sorbacal® SP and SPS

Sorbacal® SP

• Physical characteristics

 High porosity

 Surface > 40 m2/g (BET)

• High removal capacity through controlled influence 

of porosity (accessibility by acidic components)

Sorbacal® SPS

• Sorbacal® SP is activated before use to allow the 

gases to reach the porosities more easily

Important to Note: These products differ in Physical 

Structure (crystal form), but not in Chemistry (i.e. 

Ca(OH)2-Content)
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Factors That Impact DSI

Effectiveness

• Flue gas properties

 Temperature

 Moisture

 Competing acid gases

 CO2 concentration

• Reagent properties

 Particle surface area

 Pore shape, size and volume

 Particle size distribution

• System properties

 Distribution of reagent injection

 In-flight residence time

 Particulate control device
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Demonstration and 

Commercial Use Experience

• Injection trials in Europe have led 

to commercial use of DSI 

technology with Sorbacal®

products within the cement 

industry

 For SO2, HCl, HF

• Case Studies/References 

available
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Sorbacal® 

Lime Injection

Typical Cement Plant Layout
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Typical DSI Equipment Arrangement
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• August 2011 Full Scale Trial with Major Cement Producer in US

 4-Stage Pre-calciner Kiln, capacity of ~ 1 million tons of clinker a year

 Tested standard hydrate and Sorbacal® SPS

 3 Injection Locations

 1- Inlet of ID Fan 

 2- Dust Return Into Kiln Feed

 3- Inlet of Baghouse

Cement Industry Trial

3
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 Ran various injection feed rates

 Monitored HCl utilizing FTIR and SO2 by CEMS

 Collected Baghouse dust samples for chloride analysis

 Limited trial length, limitation on low end feed rate

Cement Industry Trial, con’t

• DSI Proven to be Effective Alternative 

to Scrubbers 

 Depends on site specifics, but in this trial:

 Injection at the ID Fan provided optimal 

solution 

• Temperature ~ 720F

• Good Mixing and Dispersion in Baghouse

 Cement NESHAP HCl emission limits 

(3ppm) can be achieved

• Additionally, greater than 70% removal of 

SO2 was achieved

• Both standard hydrate and Sorbacal® SP 

could meet HCl requirements, but at different 

feed rates
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Trial Results - HCl

• Standard Hydrate at Constant Feed Rate (~ 1 TPH)

 Varying Injection Locations (Temperature and Mixing)

 Result – Injection at Inlet of ID Fan Optimal Location for HCl Reduction
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Trial Results - HCl

• Standard Hydrate Injected at Optimal Injection Location (ID Fan Inlet)

 Varying Feed Rate

 Result – Can meet NESHAP HCl limit with standard hydrate at high feed 

rates 
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Trial Results - HCl

• Standard Hydrate vs. Sorbacal® SP at ID Fan Inlet

 Approximately 1 TPH Feed Rate

 Result – Can meet NESHAP HCl limit with Sorbacal® SP at this feed rate

 Limitation of this trial was feeder turn down ratio

 Lower feed rates may obtain NESHAP HCl emission limits
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Trial Results – SO2

• Standard Hydrate Injected at Optimal Injection Location (ID Fan Inlet)

 Varying Feed Rate
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Trial Results – SO2

• Standard Hydrate vs. Sorbacal® SP at ID Fan Inlet

 Approximately 1 TPH Feed Rate
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Summary

• DSI Utilizing Hydrated Lime Can Be An Effective Solution to 

Achieve NESHAP HCl Emission Limit Compliance

 Standard hydrated lime may be acceptable in some applications

 Others may require high quality enhanced hydrates such as 

Sorbacal® SP

 Will depend on site specific parameters

 Baghouse dust will need to be bled due to chloride buildup

• Next Steps

 Additional trials are to be performed at other sites to duplicate results

 Optimize feed rates required to meet the 3ppm limit

 May not require 1 TPH; this was a limitation of the feeder

• Contact

Melissa Sewell

Lhoist North America (formerly Chemical Lime Company)

melissa.sewell@lhoist.com

817.806.1549