Processes Tested:

Mineral Wool Manufacturing

Locations Monitored:

Afterburner Stack 

# Comprehensive Emissions Test Report

Afterburner Stack USG Interiors, Inc. Red Wing, Minnesota Carbon Monoxide & Sulfur Dioxide Engineering Testing

Test Date: September 13, 2005

Report Date: September 23, 2005

Prepared for:

Larry Dettmer USG Interiors, Inc.

(651) 388-3513

Prepared by:

Pace Analytical Services, Inc. Field Services Division 1700 Elm Street, Suite 200

Minneapolis, MN 55414 (612) 607-1700

Pace Project No. 0509-102

## Table of Contents

Report Cover 1 Table of Contents 2

Executive Summary 3
Introduction 4 Results Summary 5

Detail Tables 6

Table 1 CO & SO 2 Determinations, Afterburner Stack 7 Table 2 Airflow Determinations, Afterburner Stack 8

Process Description 9

Test Procedures 10 Figure 1 Test Location Schematic, Afterburner Stack 13

Signatures 14

Appendix A Field Data Sheet s and Documentation A-1 Appendix B Quantitation and Laboratory Reports B-1 Appendix C Calculation Equations C-1 Appendix D Quality Assurance Information D-1 Appendix E Source/Process/ Plant Information E-1

## Executive Summary

USG Interiors contracted Pace Analytical Services, Inc. to perform Carbon Monoxide
(CO) and Sulfur Dioxide (SO 2 ) emissions engineering testing on the afterburner stack at
the USG Interiors facility located in Redwi ng, Minnesota. Testing was performed on
September 13, 2005. Summary results ar e highlighted in the following table:

Test Results Summary

Parameter Run 1 Run 2 Run 3 Average

Volumetric Airflow

ACFM 65160 78530 72780 72160
SCFM 18310 22450 18270 19680
DSCFM 16960 20790 16910 18220

Emission Rate (LB/HR)

CO 0.21 <0.09 <0.07 <0.13
SO 2 427 538 426 463

Emission Concentration (PPM Dry)

CO 2.9 <1.0 <1.0 <1.6
SO 2 2522 2591 2523 2546

## Introduction

Pace Analytical Services, Inc. personnel conducted CO & SO 2 emission engineering
testing on the afterburner st ack at the USG Interiors facility located in Redwing,
Minnesota. James Trowbridge and Chris Norm an performed on-site testing activities.
Terry Borgerding provided administrative pr oject management. Larry Dettmer with USG
Interiors coordinated plant activities during test ing. On-site activities consisted of the
following measurements:

- CO, three independent one-hour monitoring periods.
- SO2, three independent one-hour monitoring periods.

- Orsat gas composition, integrated gas sa mples collected concurrent with above.

- Volumetric airflow, measurements during each constituent test run.

The project objectives we re to quantify CO & SO 2 emission constituents and compare
them to applicable air emissions regulations stipulated by MPCA and the facility permit.
These measurements were performed at norma l operating condition. Quality protocols
comply with all regulatory compliance testing requirements.

Subsequent sections summarize the test resu lts and provide descriptions of the process
and test methods. Supporting information and raw data are in the appendices.

## Results Summary

Results of CO & SO 2 determinations are summarized in Table 1. The CO emission rate
averaged 0.13 LB/HR at an average concentration of 1.6 PPM Dry. The SO 2 emission rate averaged 463 LB/HR at an average c oncentration of 2546 PPM Dry.

Subsequent tables provide expanded det ail of the testing results.

The data in this report are indicative of emission characteristi cs of the measured
sources for process conditions at the time of the test. Representations to other sources
and test conditions are beyond the scope of this report.

## Detail Tables

## USG Red Wing
Red Wing, Minnesota CO & SO2 Determinations Report Date: 9/23/05 Afterburner Stack TEST 1

Parameter Run 1 Run 2 Run 3 A verage Date of Run 9/13/2005 9/13/2005 9/13/2005 9/13/2005 Time of Run 1315-1400 1659-1744 1812-1857 Sample Duration (Minutes) 45 45 45

Stack Temperature (°F) 1353 1322 1569 1415 Duct Moisture Content (%v/v) 7.4 7.4 7.4 7

Volumetric Flow Rate ACFM 65,180 78,540 72,770 72,160 SCFM 18,320 22,450 18,270 19,680 DSCFM 16,970 20,790 16,910 18,220

Compound Concentration mg/dscm CO 3.3 <1.2 <1.2 <1.9 SO2 6721 6904 6724 6783

PPM, Dry CO 2.9 <1.0 <1.0 <1.6 SO2 2522 2591 2523 2546

Compound Mass Rate (LB/HR) CO 0.21 <0.09 <0.07 <0.13 SO2 427 538 426 464 

## Table 1

## USG Red Wing
Red Wing, Minnesota Airflow Measurements Pace Project No. 0509-102 Afterburner Stack Report Date: 9/23/05 TEST 1

Parameter Run 1 Run 2 Run 3 Average Date of Run 9/13/ 2005 9/13/2005 9/13/2005

Time of Measurem ent 1315 1630 1845 1315-1845

Number of Sampling Ports 2 2 2

Number of Points Sampled 16 16 16

Barometric Pressure (In. Hg) 28.97 28.97 28.97 28.97

Static Pressure (In. WC) -1.32 -1.44 -1.37 -1.38

Absolute Flue Gas Pressure (In. Hg) 28.87 28.86 28.87 28.87

Average Flue Gas Temper ature (F) 1353 1322 1569 1415

Average Moisture Content (%v/v) 7.4 7.4 7.4 7.4

Dr y Molecular Wt. of Gas ( lb/lb-mole ) 30.8 30.8 30.8 30.8

Flue Gas Average Velocity (FPS) 47.14 56.81 52.63 52.19

Duct Dimension (Inches) 65.0 65.0 65.0

Duct Cross-sectional Area (Sq. Ft.) 23.04 23.04 23.04

Volumetric Flow Rate ACFM 65,180 78,540 72,770 72,160

SCFM 18,320 22,450 18,270 19,680

DSCFM 16,970 20,790 16,910 18,220 

## Table 2

## Process Description

USG produces mineral wool at its plant in Red Wing. Mineral wool is produced by

melting and fiberizing raw materials. The major component is slag, which is a byproduct from the steel industry. Stone is used as an additive to change the melt

chemistry to produce the best quality wool for production. The mineral wool is then sent

to other facilities to be made into products such as ceiling tiles. USG has two cupolas

for melting raw materials. A cupola is a vertic al cylindrical shaft furnace used to melt

incoming minerals and then direct the molten slag out of a discharge notch. Once out of

the notch, the molten sl ag (approximately 2600 o F) flows down troughs and is then

placed on rotating wheels. As the wheel rotate s, the molten slag is forced off the wheel

into a “wall” of air, which converts (fi berizes) the molten slag into fibers. Once the

mineral wool is formed, it is collected in a large “Blow Chamber” (one for each cupola)

and is baled for shipment.

Main emission sources involved in this pr ocess are the two c upolas, where the stone

and slag are heated and melted with coke and the blow chambers where the wool fibers

are collected. Cupola melt rate is limited to 22.07 tons/hr. Pollution control equipment

for the cupolas include a baghouse and thermal oxidizer. Pollution control equipment for

the blow chamber includes a dr y filter system. After the air passes through the dry filter

system, then it is exhaus ted to the atmosphere.

The operating rates for the test were withi n the range of normal ope rating parameters.

## Test Procedures

EPA Method 1 specifies test location acceptabilit y criteria and defines the minimum number of traverse points fo r representative sampling. Linear measurements from upstream and downstream flow disturbances and the duct equivalent diameter are compared and the distances related to number of diameters. A flow disturbance can be defined as anything that changes or upsets the direction of fl ow within the duct including bends, dampers, fans, shape or size transitions and open flames. Method 1 stipulates that test ports should be loca ted at least eight diameter s downstream and two diameters upstream of any flow disturbanc e. The minimum acceptable criteria are two diameters downstream and 0.5 diameters ups tream of flow disturbances. The test location must also be free of cyclonic or multidirectional flow. Once the distances have been determined, the values are used to select the minimum number of traverse points for representative sampling. Shorter distances r equire a greater number of traverse points. The test site configuration is shown in Figure 1 and has the following characteristics:

Test Location: Afterburner Stack Duct Cross-sectional Dimension: 65” Distance From Upstr eam Disturbance: ~1620“ Number of Duct Diameters: ~24.9 Distance To Downstream Disturbance: ~204 “ Number of Duct Diameters: ~3.1 Cyclonic or Multidirectional Flow: No, verified Number of Traverse Points: 16

EPA Method 2 defines procedures used to measure linear velocity and volumetric flow rate of a confined gas str eam. Using traverse points determined by EPA Method 1, multiple differential pressure measurem ents (pitot impact opening versus static pressure) are made using a pitot tube and diffe rential pressure gauge. The individual measurements are averaged and combined with the gas density to calculate the average gas velocity. The velocity and duct cross-sectional area are used to calculate the volumetric flow rate. The volumetric flow rate is expressed as actual cubic feet per minute (ACFM), standard cubic f eet per minute (SCFM), and dr y standard cubic feet per minute (DSCFM). The technician maintains comprehensive test records on handwritten field data sheets. Details of the equipment used to measure gas velocity include:

Pitot Tube: S-Type Differential Pressure Gauge: Oil Manometer Temperature Device: Type K Thermocouple Barometer Type: Electronic Digital Barometer Gas Density Determination: EPA Method 3 Gas Moisture Determination: EPA Method 4

EPA Method 3B defines procedures to quantify carbon dioxide (CO 2 ) and oxygen (O 2 ) concentrations from stationary combustion s ources. A multi-poi nt, integrated, gassample is collected simultaneously with other emissions testing. Using traverse points determined from EPA Method 1, sample gases ar e extracted from em ission stream at a constant rate. Each point is sampled for a uniform length of time over the course of a test period equal to other test constituents. A TedlarTM, aluminized MylarTM or other inert material bag contains t he collected gas sample prior to sample analyses. An Orsat gas analyzer quantifies the CO 2 and O 2 concentrations by measuring the changes in volume after selective chemical gas adsorpti on. Below are the deta ils of the procedures for measuring gas composition:

Filter Material: Glass fiber filter or equivalent Moisture removal: Condenser Bag Material: Aluminized MylarTM Gas Analyzer: Orsat

EPA Alternative Method 4 defines procedures to measur e the moisture content of emissions gas streams from stationary sour ces. The moisture content of the gas stream is determined using alternative Me thod 4. Wet bulb/dry bulb temperature measurements of the gas stream are re corded. Psychometric charts and vapor pressure of water tables are used to calculat e the moisture content of the gas streams.

EPA Method 6C defines procedures to m easure sulfur dioxide (SO 2 ) from stationary sources. A stainless steel sampling probe and a heat-traced TeflonTM sampling line draw a sample of the gas stream from the duct to a thermo-electric gas conditioner to remove moisture. The sample gas stream is delivered to an API M600CLD ultraviolet gas analyzer to quantify SO 2 emissions. Zero grade cylinder air provides zero gas and span gases include varying concent rations of EPA Protocol 1 SO 2 standards. A computerized data acquisition system and stripchart recorder (in parallel) log SO 2 concentrations for one-minute averages. T he logged results are integrated to test periods and tabulated with sp readsheet software. The operator also maintains comprehensive test records on handwritten fi eld data sheets. Equipment used for SO 2 testing include:

Probe Material: Stainless Steel Moisture Removal: Thermo-electric Transfer Line: TeflonTM Instrument: API M600CLD Analytical Technique: Ultraviolet detector Calibration Gas: EPA Protocol 1

EPA Method 10 defines procedures to measure Ca rbon Monoxide (CO) emissions from stationary sources. A st ainless steel sampling probe and a heat-traced TeflonTM sampling line draw a sample of the gas stream from the du ct to a thermo-electric gas conditioner to remove moisture. The samp le gas stream is de livered to a Thermo Environmental Instruments Model 48H non-dispersive in frared analyzer to quantify CO concentrations. Zero grade cylinder air pr ovides zero gas and span gases include varying concentrations of EPA Protocol 1 CO standards. A computerized dataacquisition system and stripchart recorder (in parallel) log CO concentrations for oneminute averages. The logged results are int egrated to test peri ods and tabulated with spreadsheet software. The oper ator also maintains comprehensive test records on handwritten field data sheets. Equipm ent used for CO testing include:

Probe Material: Stainless Steel Moisture Removal: Thermo-electric Transfer Line: TeflonTM Instrument: TEI Model 48H Analytical Technique: Non-dispersive Infrared Calibration Gas: EPA Protocol 1

## Report Signatures

Field Testing and Reporting Performed by: Pace Analytical Services, Inc. Field Services Division 1700 Elm Street, Suite 200 Minneapolis, MN 55414

Field Testing Affirmation

All field testing was performed in accordance with stated test methods subject to modifications and deviations listed herein. Raw field data presented in this report accurately reflects results and information as recorded at the time of tests or otherwise noted.

_________________________________ Date _____________ James Trowbridge Field Analyst

Report Affirmation

To the best of my knowledge, this report accurately represents the compiled field and laboratory information with no material omissions, alterations or misrepresentations.

Responsible Charge Affirmation

I have reviewed the information herein and it is approved for distribution.

_________________________________ Date _____________ Terry Borgerding Operations Manager Air/Water