DEPARTMENT OF TE TRANSPORT 662 .A3 OCT 2 - 197Z leport No. FHWA-RD-72-15 no.FHWA- LIBRARY RD-72-15 Tunnel Ventilation and Air Pollution Treatment S. J. Rodgers, F. Roehlich, Jr., and C. A. Palladino Mine Safety Appliance Research Corporation Evans City, Pennsylvania 16033 " 4 *r5 ov June 30, 1970 This document is available to the public through the National Technical Information Service, Springfield, Virginia 22151. Prepared for FEDERAL HIGHWAY ADMINISTRATION Office of Research Washington, D.C. 20590 NOTICE This document is disseminated under the sponsorship of the Department of Transportation in the interest of information exchange. The United States Government assumes no liability for its contents or use thereof. The contents of this report reflect the views of the contracting organization, which is responsible for the facts and the accuracy of the data presented herein. The contents do not necessarily reflect the official views or policy of the Department of Transportation. This report does not constitute a standard, specification, or regulation. — , , ot TE "department \{\Jnv+*y Aolm.'n.'str^^n. TRANSPORTATION u.S. ^e^er^l •; .A3 no- FHWA- ^ "ECHNICAL REPORT tTANTD^ T$T CE l|Q(?2. 1. Report No. 2. Government Accession No. 3. Recipient's CataloglNo. .-/r FHWA-RD-72-15, LIBRARY 4. Title and Subtitle 5. Report Dote \s * QctOl Tunnel Ventilation and Air Pollution Treatment Date of Preparation 6. Performing Organization Code 7. Author's) 8. Performing Organization Report No. Sheridan J. Rodgers , Ferdinand Roehlich, Jr., Cataldo A. Palladino MSAR-71-187 9. Performing Organization Name and Address 10. Work Unit No. Mine Safety Appliance Research Corporation FCP 33F3012 Evans. City, Pennsylvania 16033 11. Contract or Grant No. FH-ll-7597 13. Type of Report and Period Covered 12. Sponsoring Agency Name and Address Final Report U.S. Department of Transportation June 30, 1970 Federal Highway Administration Washington, D. C. 20590 14. Sponsoring Agency Code Ab 2980 15. Supplementary Notes 16. Abstract The dangers such as harmful physiological effects and nuisances for various tunnel air impurities for occupants were usually negligible, especially because of limited exposure periods. Only carbon monoxide, hydrocarbons, nitrogen oxides, and particulates pose any significant problems. From the foregoing analysis, standards of American Conference of Government and Industrial Hygienists, Federal ambient air and occupational safety and health regulations, and tunnel occupancy, tentative limits include: Safety for Unmanned Tunnels Carbon Monoxide 500 ppm Nitric Oxide 37.5 ppm Nitrogen Dioxide • 5 ppm Particulates lOmg/meter" A computer program was developed and validated to predict various significant air contaminants. Instrumentation to monitor tunnel air quality was proposed. Treatments of tunnel air for either discharge to the surroundings or recycling were examined. Economic and processing constraints such as dilute concentrations were probed. Limited laboratory tests were conducted. Removal of carbon monoxide appears to be impractical. Adsorption of nitrogen dioxide and more noxious hydrocarbons by activa- ted carbon showed promise. Particulates can be largely removed by electrostatic precipitation, filtration, and wet scrubbing. 17. Keywords 18. Distribution Statement TnTinel f Mr pollutants Availability unlimited. Ventilation Instrumentation, Air Purifica' The public can obtain this document through tion, Air Quality Standards the National Technical Information Service, Springfield, Virginia 22151. 19. Security Classif. (of this report) 20. Security Classif. (of this page) 21. No. of Pages 22. Price Unclassified Unclassified 267 Form DOT F 1700.7 <s-69) ABSTRACT This study, funded by the Department of Trans- portation, Federal Highway Administration, was aimed at evaluating current air quality in existing tunnels and determining means of upgrading air quality in existing and future tunnels. The study consisted of six phases: 1. Identify the types and quantities of impurities in vehicular tunnels. 2. Evaluate the physiological effects of these impurities on tunnel workers and transients. 3. Establish air quality criteria for vehicular tunnels. 4. Determine available methods for improving air quality in vehicular tunnels. 5. Perform laboratory tests to demon- strate the applicability of selected purification procedures. 6. Recommend instrumentation for vehicular tunnels. Phase 1 consisted primarily of a literature survey of past tunnel studies as well as vehicle emission rates as a function of various driving modes. Those of major concern are CO, N0 X , HC and particulates. A computer program was developed which adequately predicts the concen- tration of various impurities as a function of driving mode and ventilation rates. Some on-site sampling was performed to verify the validity of the computer program. Phase 2 involved a survey of the literature to determine both short term and long term effects on humans exposed to specific tunnel impurities. These effects were considered in terms of both safe levels and comfort levels with respect to tunnel employees and tunnel transients. The work of Phase 3 evolved as a result of the findings in Phase 2. Criteria for tunnel impurity levels were established with the basic guidelines being the Recommended Levels of the American Conference of Governmental Industrial Hygienists, the EPA standards as set forth 1n the Federal Register and other references on the effects of air impurities on safety and comfort. Phase 4 involved a review of current literature on methods and procedures for purification of contaminated atmospheres. Typical purification systems which were reviewed included catalytic combustion, adsorption, absorp- tion, wet scrubbing and electrostatic precipitation. These methods were considered within the constraints imposed by tunnel atmospheres (i.e., low impurity levels and large gas volumes). An economic evaluation of selected systems was made. Phase 5 reguired laboratory evaluation of the most promising methods of tunnel atmosphere purification. Small scale testing was performed in a chamber containing actual automobile exhaust gases. Parameters which were studied included temperature, space velocity, residence time and so on. Hopcalite at 225°F to 250°F reduced the CO to zero. Activated carbon proved to be effective in the removal of NO2 and heavy hydrocarbons. Phase 6 reguired the recommendation of impurity monitors which should be used in tunnels. For tunnels where the air guality is maintained by ventilation, the recommen- dation was made that CO continued to be monitored and used as the primary indicator of tunnel ventilation rates. It was also recommended that smoke meters be installed in tunnels, particularly those which have heavy diesel traffic. TABLE OF CONTENTS Page No INTRODUCTION 1 RESULTS OF THE PROGRAM 3 Identification of Types and Quantities of Impurities in Vehicular Tunnels 3 Literature Survey 3 Computer Model 21 Emission Rates for CO, H-C, N0 X and Particulates 38 Verification of Computer Model 45 PHYSIOLOGICAL EFFECTS OF TUNNEL CONTAMINANTS 69 Contaminants Which Have Been Found in Tunnel Atmospheres 69 Selected Contaminant Levels for Vehicular Tunnels 72 Specific Limits for Manned Tunnels 72 Unmanned Tunnels 76 Summary of Recommended Levels 79 EVALUATION OF POLLUTANT REMOVAL METHODS 81 State of the Art - Applicable Control Technology 81 Applicable Tunnel Pollution Control Technology 83 Carbon Monoxide and Hydrocarbons 84 Catalytic Oxidation 87 Thermal Afterburning 93 Adsorption 94 Wet Scrubbing 97 Nitrogen Oxides 101 Source Control 105 Particulates 108 Tunnel Pollution Control - Feasibility and •Economic Evaluation 113 Tunnel Pollution Control Strategies 116 Exhaust Emission Projections 119 Tunnel Air Treatment: Problem Statement 125 Tunnel Ventilation Costs 130 Process Feasibility: CO and Hydrocarbons 134 Process Feasibility: Hydrocarbons 139 Process Feasibility: Particulates 143 Process Feasibility: Water Solubles 150 General Feasibility: Recycle & Compart- mentali zation 151 iii TABLE OF CONTENTS (Continued) Page No. Conclusions of Alternative Control Technologies 155 Selection of Control Techniques to be Evaluated 158 General Discussion 158 Carbon Monoxide Removal Systems 159 Hydrocarbons 159 Oxides of Nitrogen 159 Particul ates 160 Purification Test System 160 Run No. 1 - Blank 162 Run No. 2 - Cold Hopcalite 164 Run No. 3 - Activated Carbon 164 Run No. 4 - Purafil 166 Run No. 5 - Hot Hopcalite 166 Run No. 6 - Silica Gel -Hopcal i te 166 Run No. 7 - Hopcalite 167 Runs 8 and 9 - Filter Media 167 Run No. 10 - Mn02-Cu0 167 Run No. 11 - Charcoal Plus Hopcalite 167 Run No. 12 - Charcoal Plus Moisture Tolerant Hopcal i te 168 Purification Systems for Tunnels 168 TUNNEL INSTRUMENTATION 171 Carbon Monoxide ' 171 Smoke or Haze 173 Other Monitors 174 Hydrocarbons 174 Nitrogen Oxides 174 Total Aldehydes 174 Carbon Dioxide and Oxygen 174 Recommendations for Tunnel Instrumentation 174 CONCLUSIONS 177 REFERENCES 181 BIBLIOGRAPHY 191 A. Specific Tunnel Studies 191 B. General Tunnel Studies 192 C. Emission Rates 194 D. Traffic Surveys and Studies 197 E. Ventilation Requirements and Equipment 199 F. Physiological Effects 201 G. Emission Control 204 H. Pollutant Monitoring 205 TABLE OF CONTENTS (Continued) Page No. APPENDIX I - Final Report - IHF 209 APPENDIX II - Pollutant Removal Proceas Calculations 241 from Final Report — Patent Development Associates, Inc. LIST OF ILLUSTRATIONS Figure No. Page No m ii 1 Mean Hourly Traffic Flow Through Sumner Tunnel , By Time and