INL RESEARCH & DEVELOPMENT

Science

Advanced Offgas Test System

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Background

For decades, INL has developed, tested, and used a wide

variety of mixed waste

treatment technologies and

offgas control systems

designed specifically for use

in mixed waste treatment.

Treatment technologies have

included fluidized bed

calcination, melting, incineration, steam reforming, thermal

desorption, low-temperature

oxidation, super-critical water

oxidation, and thermal

desorption. Offgas control

technologies and systems

have been tailored to meet

specific technology and

regulatory requirements while

maximizing performance in

mixed waste facilities.

Several small and pilot-scale

test systems currently exist at

INL for mixed waste treatment and offgas system

testing – including the

recently built Advanced

Offgas Test System.

About the System

This advanced test system

includes innovative control

technologies designed and

optimized for potential use in

calcination, steam reforming,

vitrification and other thermal

treatment processes. This test

bed is uniquely designed to

demonstrate technologies for

compliance with applicable

air emission regulations

including the Environmental

Protection Agency’s Hazardous Waste Combustor Maximum Achievable Control

Technology standards.

The Idaho National Laboratory has developed, tested and used different offgas system

designs and technologies for mixed waste thermal treatment. The Advanced Offgas

Test System provides a pilot-scale offgas test capability for testing individual offgas

control technologies in an integrated system. The System components, configuration, source

term and operation can be varied for specific test objectives.

System Description

The modular nature of this

system can be modified to fit

various potential configurations. The illustration on the

reverse side is a process

diagram of the system used in

conjunction with INL’s Cold

Crucible Induction Melter.

The following is a brief

description of each stage in

the process.

Thermal Reaction

Chamber— This chamber

performs nonselective, noncatalytic NOx

 reduction in a

three-stage process. The

offgas is first heated electrically to 1200°C and a reductant is injected to create a

reducing atmosphere where

NOx is reduced to N2. Then,

water is injected to reduce the

temperature to about 850°C.

Finally, air is injected to

complete oxidation of the

carbon monoxide and other

products of incomplete

combustion produced in the

first stage.

Quench— Offgas leaving

the Chamber is fully

quenched to about 70°C.

Wet Electrostatic Precipitator Scrubber— A wet

electrostatic precipitator

scrubber is designed to

This Advanced Offgas Test

System is the cornerstone of

the INL’s integrated offgas test

bed system that allows pilotscale research.
INL RESEARCH & DEVELOPMENT

Management Contact

Nolan Olson

Manager, Process

Engineering Department

Nolan.Olson@inl.gov

(208) 526-4161

Technical Contacts

Nick Soelberg

Nicholas.Soelberg@inl.gov

(208) 526-6923

Steve Priebe

Stephen.Priebe@inl.gov

(208) 526-0898

INL R&D

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05-GA50158

efficiently remove acid gases

and residual particulate

matter. This scrubber is

unique in that water-cooled

tubes condense some of the

moisture in the offgas –

improving the scrubbing

performance.

Reheater— After scrubbing,

the offgas is reheated with air

to raise the temperature above

its dew point.

HEPA Filter— Although not

required in all systems,

provision has been made, in

this example, to include a

HEPA filter for final filtration.

Activated Carbon Bed

Adsorber— A vertical bed

of activated carbon removes

mercury in the offgas. If

interested in removing other

species, such as acid gases,

the activated carbon can be

replaced with other sorbents.

Selective Catalytic Reduction— Provision has

been made to add a selective

catalytic reduction unit after

the carbon bed adsorber. If

there is a need to study

another reduction unit, then

the chamber at the front of the

offgas system will not be

operated.

Induced Draft Fan— A

100 standard cubic feet per

minute (scfm) induced draft

fan provides the motive force

for the offgas system.

Instrumentation— The

system is fully instrumented

with process controllers and

pressure, temperature and

flow indicators. Ports are

located throughout the system

to allow access for sample

and continuous emission

monitor probes.

System Capabilities

The system has a nominal

inlet flow rate range of five to

ten scfm. The inlet offgas

temperature can range from

200°C to about 1200°C. The

gas composition to be tested

can vary using compressed

gas mixtures to simulate

many different offgas source

terms. Additionally, various

thermal process units can be

integrated into this system,

such as the Cold Crucible

Induction Melter or a fluidized bed unit. This flexibility

allows the capability to

provide representative offgas

source terms for most of the

technologies being employed

or considered by DOE for

processing radioactive waste.

Conceptual process

diagram for the

Advanced Offgas

System test bed.

Idaho National

Laboratory

P.O. Box 1625

Idaho Falls, ID 83415

Cold Crucible

Induction Melter

Thermal

Reaction

Chamber

Quench

Scrub Tank

Wet Electrostatic

Precipitator Scrubber

Reheater

HEPA Filter

Selective

Catalytic

Reduction

Induced

Draft

Fan

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