Dry Sorbent Injection

for SO2, SO3, Hg and HCl
SO2, SO3 Dry Sorbent Injection , Hg & HCl

Our experience, technology and customer support set 

UCC apart from other suppliers. UCC ensures optimum 

plant performance through sophisticated predictive 

modeling for the injection grid design, on-site testing 

to validate sorbent type and injection rate, and proactive 

lab testing and evaluation of the effects on existing ash 

handling systems. UCC offers the expertise, confidence 

and single point accountability our customers expect in 

dry sorbent injection systems.

•	Performance-based turnkey solutions

•	Over 25,000 hours of DSI demonstration testing

•	VIPERTM mill technology delivers the highest

	 removal efficiency and greatest cost savings

Utilities are actively evaluating various technologies and strategies to comply with EPA emissions 

regulations. Removal efficiency, capital and operating cost, plant life, outage requirements, 

scalability and impact on existing air pollution control (APC) equipment are typical considerations 

and trade-offs. Many plants have determined that Dry Sorbent Injection (DSI) delivers a simple, 

low cost solution to effective pollution control for their environmental fleet planning. 

Since 2004, United Conveyor Corporation (UCC) has pioneered dry sorbent injection technology 

which injects selected sorbents into the flue gas to control SO2, SO3, mercury and HCI. UCC leads 

the industry in demonstration testing and is recognized as the technology leader that delivers 

system performance and confidence to our customers. Our experience removes the guesswork 

and we work closely with customers to deliver a reliable solution to each plant’s specification. 

UCC Advantage

Many plants are looking for a single, comprehensive solution for the removal of 

pollutants required by EPA MATS and CSAPR/CAIR regulations. Determining factors 

include complex chemistry, fluid dynamics, sorbent selection, injection location and 

interaction with existing APC equipment such as ACI systems, fuel additives and 

fabric filter / ESP collection. UCC has extensive experience with simultaneous SO2, 

SO3, HCI and Hg removal to deliver comprehensive compliance strategies in a timely 

and economical manner. 

Multi-Pollutant Control Capability

UCC is committed to innovation and technology that deliver performance 

advantages in our dry sorbent injection systems. Continuing efforts focus on 

particle dispersion to improve removal efficiency, elimination of plugging 

and system design practices that drive operational reliability. 

•	Splitters

The UCC design is optimized and tested for even sorbent distribution 

and high removal efficiency while minimizing the risk of plugging.

•	Injection Lances

The unique UCC design maximizes particle dispersion and eliminates 

plugging with no impact on pressure drop. 

•	CFD Modeling

UCC specializes in Computational Fluid Dynamic (CFD) modeling of 

plant duct flows to predict and enhance sorbent distribution in flue gas, 

thereby maximizing performance and minimizing sorbent usage.

Innovation

•	Hydrated Lime

•	Trona

•	Sodium Bicarbonate

•	Activated Carbon

•	Other Mercury Sorbents
Confidence On-Site Test and Demonstrations

UCC has conducted over 65 full-scale demonstration 

tests and has over 25,000 hours of experience. This is 

the most hands-on, practical experience in the industry 

and provides clear differentiation in a crowded market. 

UCC test experience includes a strong technical 

understanding of SO2, SO3, HCI and Hg removal and 

any multi-pollutant combination. 

Our fleet of mobile test equipment incorporates the 

latest injection and milling technology and is fully 

automated to generate reliable, high quality data. 

This unique capability provides the answers our 

customers need to make critical compliance decisions.

Full-scale, on-site demonstration testing is used to validate the plant’s compliance strategy 

and optimize the overall performance of the DSI system. Utilities understand the need to 

report compliance decisions to shareholders, and therefore require experienced planning, 

execution and professional reporting of demonstration tests. 

Every boiler unit is unique and emissions are influenced by coal type, combustion conditions, 

ductwork, temperature and other APC equipment. During testing, modifications can be 

made to the injection grid, sorbent combinations and injection rates to maximize emissions 

removal. The ability to devise a meaningful, customized test plan and efficiently confirm 

emissions compliance is heavily influenced by prior experience.

When you need it done right, 

you can count on UCC

UCC process engineers are actively involved to ensure that demonstration testing goes smoothly and that the 

results directly support emission control strategy decisions.

• CFD modeling (computational fluid dynamics) of the particle dispersion can be used to predict and enhance

performance and minimize sorbent usage prior to testing.

• Test matrices are developed that leverage UCC experience and data from previous tests. Conveying 	 	

requirements are determined using UCC proprietary pneumatic programs. 

• A comprehensive test plan is submitted to the plant in advance and serves as the “playbook” for execution.

UCC demonstration equipment incorporates the latest injection 

and milling technology and is installed and operated with minimal 

disruption to the plant.

• The industry’s most experienced field engineers are on-site for

supervision, operation and troubleshooting.

• DSI process engineers are on-site to provide real-time data

evaluation, consultation, and test plan adjustments as required 

to achieve best results.

The DSI process engineer consolidates and evaluates all the raw 

data from the COMS, CEMS, testing PLC and source testing. 

• Removal results are compared to a database of previous site

testing to confirm performance and improve results.

• A final test report is provided that summarizes the data and

reviews it against the test objectives.

• UCC personnel are a continuous resource during plant/fleet

emission control strategy evaluation and decision making.

Preparation and Logistics

Execution

Data Evaluation and Reporting

25,000+

•	Number of Demonstrations 65+

•	Over 25,000 Hours

	 Of Testing
Performance Advantage VIPERTM Mill Technology

The VIPERTM Mill is proven, reliable technology developed specifically for dry sorbent

injection. The patented VIPER Mill operates in-line with the DSI system and delivers the

smallest particle size, highest throughput and greatest cost savings in the industry. The 

result is 30-50% lower sorbent usage compared with as-delivered material. 

• Designed for trona and sodium bicarbonate

• Capacity: 0.5 – 7 tons per hour

• Median particle size: 9-15 μm (trona), 15-19 μm (SBC)

• Reduced sorbent usage saves millions of dollars

VIPER Milled Trona VIPER Milled SBC

Unmilled Trona Unmilled SBC

Trona Sodium Bicarbonate

Particulate Size – Trona Particulate Size – Sodium Bicarbonate 

Skid Mounted Installation with Automated Cleaning

The only mill developed 

specifically for DSI systems

tons per hour

operation

7

24/7

The VIPER Mill is equipped with an automated cleaning system to eliminate

sorbent build-up. The 30-minute cleaning cycle ensures consistency in particle 

size while balancing horsepower, temperature rise and sorbent 

throughput. The VIPER Mill uses either a simple bypass system

or redundant skid for uninterrupted DSI operation.

The VIPER Mill ships on a fully pre-piped and pre-wired skid

for simple installation and lower installed cost.
Dry Sorbent Injection Economic Advantage

VIPER Mill technology saves

utilities millions annually

The annual savings using VIPER Milling technology typically results in a payback

period of less than one year. Integration of a single VIPER Mill can reduce sorbent

costs by millions of dollars annually compared to other DSI systems. 

In a typical SO3 removal application, the 

VIPER Mill achieves aggressive ppm targets

while saving nearly $1 million per year 

compared with unmilled trona.

Dry sorbent injection is readily added to existing units and has a lower capital cost, yet 

higher operating cost, compared with dry scrubbers. An economic analysis comparing 

these solutions concludes that UCC’s DSI system with VIPER Mill technology has a lower

cash outlay and net present value beyond 15 years. Each plant has a unique footprint 

in terms of size, life expectancy, efficiency target and financial position and should 

consider all variables in their specific evaluation. 

In a typical SO2 removal application, the 

VIPER Mill can reduce sorbent usage by

30-50%. This delivers a $3.0 million 

annual savings over unmilled trona for a 

typical 500-MW PRB unit at a 60 percent

removal rate.

VIPER Mill –Smart Investment DSI vs. Dry Scrubber

Unmilled vs. UCC Milled Trona

Unit 

(MW)

SO3

(ppm)

SO3 Reduction

(% Removal)

Unmilled 

(ton/hr) Fine Milled

(ton/hr)

Annual 

Savings*

700 25 90% 0.7 0.4 $ 425,736

700 35 90% 1.0 0.5 $ 709,560

700 50 90% 1.3 0.6 $ 922,428

SO3 Economics

Eastern Bituminous Coal: Unmilled Trona vs. UCC Milled Trona

PRB: Unmilled Trona vs. UCC Milled Trona

Unit 

(MW)

Sulfur 

lb/mmbtu

SO2 Reduction

(% Removal)

Unmilled 

(ton/hr) Fine Milled

(ton/hr)

Annual 

Savings*

50 1.6 60% 2.4 1.7 $ 993,384

100 1.6 60% 4.8 3.4 $1,986,768

150 1.6 60% 7.2 5.1 $2,980,152

Unit 

(MW)

Sulfur 

lb/mmbtu

SO2 Reduction

(% Removal)

Unmilled 

(ton/hr) Fine Milled

(ton/hr)

Annual 

Savings*

100 0.8 60% 1.5 1.1 $ 638,604

250 0.8 60% 3.8 2.7 $1,617,797

500 0.8 60% 7.5 5.3 $3,193,020

SO2 Economics

* Based on Trona at $180/ton

Dry Sorbent 

Injection Dry Scrubber

Efficiency Target

90% SO2

90% HCl

90% Hg 

removal with ESP and 

milled trona/activated 

carbon

90% SO2

90% HCl 

90% Hg 

removal with ESP

Outage for Installation None 1 month

Lead Time 12 months 2 years

System Costs

(includes installation) $25M $250M

Operating Cost

(w/ sorbent costs) $20M / yr. $6.6M / yr.

90% Removal – 600MW Unit with ESP/PRB Coal Cumulative Cash Outlay (NPV)

Milled Trona Injection Rate vs. Outlet SO3 Concentration

Hydrated Lime Injection

DSI systems are suitable for retrofit into units with 

SCRs and/or wet scrubbers for effective SO3 control. 

UCC has experience using hydrated lime and trona 

injection for SO3 removal and has achieved SO3

emission limits well below 5 ppm. Where trona is 

preferred, VIPER Milling technology will reduce sorbent

usage by 50%.

SO3 Removal with Cost Savings
Confidence Service and After-Market Support

The UCC commitment to quality is backed by 

thousands of hours of development, testing and 

evaluation. United Conveyor Corporation has one 

of the world’s most advanced research laboratories 

and conveyor test loops to simulate ash and 

reagent handling applications and validate design 

parameters. Our knowledge and experience in 

material behavior, product innovation and system 

development for challenging applications is 

unmatched in the industry. 

The addition of a DSI system introduces calcium or sodium-based by-products to the existing ash 

handling system. These by-products can alter the material characteristics of the existing fly ash, 

thereby affecting its flow properties and performance of existing hoppers and conveying pipes. In 

SO2 applications, the additional solids load could exceed the design capacity of your existing system. 

As the global leader in ash handling, UCC offers a comprehensive evaluation of your plant’s 

current ash removal capacity. We will analyze the ash by-product and recommend any system 

changes to accommodate the increased load and altered material flow characteristics caused by 

the sorbent injection.

Potential Impact to Existing Ash System

UCC supports you for 

the life of your system 

UCC is committed to providing the highest level of service for as long 

as you own your system. Our field service engineers are available worldwide 

to assist with erection and start-up, operator training and maintenance.

•	Replacement Parts

UCC offers the most readily available inventory of replacement parts to minimize 

downtime and reduce operating costs. Thousands of replacement parts are in stock and 

ready for next day shipment.

•	Preventative Maintenance

This program is designed to keep your DSI system operating at peak efficiency, proactively 

prioritizing maintenance resources and minimizing the risk of unexpected downtime.

•	Pre-outage and Outage Assistance

UCC inspection and advance planning ensures that parts are on-site before work begins, 

installed properly and tested, to deliver a smooth start-up.

UCC project management, field service and process engineering 

teams work hand-in-hand with customers to provide seamless 

execution of specification development, test and demonstration, 

design, erection and start-up, operation and maintenance training. 

UCC maintains a group of dedicated DSI process and field service 

engineers to work directly with customers during all phases of 

work, including after-market support.

Project Implementation and

Knowledgeable Resources
As an industry innovator, we have long been at the forefront of ash 

handling technology. We recognize the importance of providing customers 

with the best equipment and latest technology that meet their demanding 

requirements and plant needs.

With our own advanced testing and technology lab, we are able to maintain 

control over the quality and delivery of our systems and equipment. The 

result is superior and predictable performance for our customers.

Our dedicated team of engineers, sales, service and in-house designers 

spans the globe covering six continents, assuring you that we can provide 

exceptional service whenever needed. This is our commitment to you.

The UCC Commitment

unitedconveyor.com

Global Operations in:

United States • Europe • China • India

Systems in over 60 Countries

UCC® is a registered trademark of United Conveyor Corporation. All enclosed content is provided for information only. 

United Conveyor Corporation reserves right to change without notice any information contained within.

M13-02 ©2013 United Conveyor Corporation

UCC Material Handling Solutions

Fly Ash (Dilute, Medium and Dense Phase)

• Vacuum Systems

• Pressure Systems

Bottom Ash (Wet and Dry)

• Hydraulic Systems

• Pneumatic Systems

• Mechanical Systems

• Vibratory Systems

Mill Rejects

• Hydraulic System

• Pneumatic Systems

Economizer Ash

• Hydraulic Systems

• Mechanical Systems

• Pneumatic Systems

Dry Sorbent Injection

• Predictive (CFD) Modeling

• On-Site Testing and Demonstration

• Pneumatic Systems

• Installation

Lime Handling

• Truck and Rail Unloading

• Pneumatic Systems

System Components

• Crushers

• Mixer/Unloaders

• Gates/Valves

• Pipe/Fittings

• Filter/Separators

• Tanks/Vessels