And Particulate Matter Emissions from Heavy-Duty Natural Gas Engines
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Graduate Theses, Dissertations, and Problem Reports 2006 Reduction of Toxic Air Contaminants (TACs) and particulate matter emissions from heavy-duty natural gas engines Hemanth K. Kappanna West Virginia University Follow this and additional works at: https://researchrepository.wvu.edu/etd Recommended Citation Kappanna, Hemanth K., "Reduction of Toxic Air Contaminants (TACs) and particulate matter emissions from heavy-duty natural gas engines" (2006). Graduate Theses, Dissertations, and Problem Reports. 1707. https://researchrepository.wvu.edu/etd/1707 This Thesis is protected by copyright and/or related rights. It has been brought to you by the The Research Repository @ WVU with permission from the rights-holder(s). You are free to use this Thesis in any way that is permitted by the copyright and related rights legislation that applies to your use. For other uses you must obtain permission from the rights-holder(s) directly, unless additional rights are indicated by a Creative Commons license in the record and/ or on the work itself. This Thesis has been accepted for inclusion in WVU Graduate Theses, Dissertations, and Problem Reports collection by an authorized administrator of The Research Repository @ WVU. For more information, please contact [email protected]. Reduction of Toxic Air Contaminants (TACs) and Particulate Matter Emissions from Heavy-Duty Natural Gas Engines Hemanth K. Kappanna Thesis Submitted to the College of Engineering and Mineral Resources at West Virginia University in partial fulfillment of the requirements for the degree of Master of Science in Mechanical Engineering Mridul Gautam, Ph.D., Chair Gregory. J. Thompson, Ph.D. W. Scott Wayne, Ph.D. Daniel. K. Carder, M.S. Department of Mechanical and Aerospace Engineering Morgantown, West Virginia 2006 Keywords: Exhaust Aftertreatment, Speciation, Toxic Air Contaminants, Natural Gas Engines ABSTRACT Reduction of Toxic Air Contaminants (TACs) and Particulate Matter Emissions from Heavy-Duty Natural Gas Engines Hemanth K. Kappanna Increasing urban pollution levels have driven the Federal and the local air control boards to impose stricter emissions regulations on heavy-duty engines earmarked for transit buses. This has made natural gas a promising fuel for reducing the emissions of oxides of nitrogen and predominantly particulate matter from heavy-duty transit buses. Recent research studies performed at WVU and elsewhere have showed that natural gas engines emit an order of magnitude lower PM emissions, on a mass basis, when compared to diesel engines without any exhaust aftertreatment devices. However, on a number basis the emissions from natural gas fueled buses were an order of magnitude higher than their diesel counterparts. This project was initiated by Southern California Air Quality Management District to design and develop an exhaust aftertreatment device for retrofitting urban transit buses powered by heavy-duty natural gas engines. The exhaust aftertreatment device was developed for a Cummins Westport C8.3G+ natural gas engine. Exhaust samples were collected by operating the vehicle on the Central Business District cycle on a chassis dynamometer. Regulated emissions were continuously measured while non- regulated emissions samples were collected on different media from a full flow dilution tunnel. In addition, PM concentrations and size distributions were also measured. The project consisted of three phases. In Phase I, complete speciation of the emissions and particle size measurements were performed from the engine, with and without the OEM oxidation catalyst. Based on this data, WVU and Lubrizol developed an exhaust aftertreatment device which consisted of a particulate filter and an oxidation catalyst. The emissions measurement from the transit bus with the newly installed exhaust aftertreatment device was performed in Phase II. After six months of on-road demonstration, the exhaust aftertreatment device was retested in Phase III to check for any deterioration in the performance. The speciation results showed that the new exhaust aftertreatment device reduced the emissions of metallic elements like iron, zinc and non- metallic minerals like calcium, phosphorus and sulfur derived from lube oil additives to non-detectable levels, which otherwise would form nuclei mode particles, thereby increasing the number of nanoparticles. The carbonyl compounds were reduced effectively by the oxidation catalyst to the levels below what were found in the dilution air. The PAHs and other heavier hydrocarbons identified as Toxic Air Contaminants (TACs) by CARB were reduced to non-detectable levels. This ultimately reduced the number of nanoparticles to the levels equal to that found in the dilution air. The Phase III results showed that the aged aftertreatment device performed efficiently without any deterioration. ACKNOWLEDGEMENTS As this brings me to the end of an extended master's career I would like to take this opportunity to thank all those who have supported me in fulfilling my aspirations. First and foremost, I would like to thank my advisor, Dr. Mridul Gautam, for accepting me as his student, for the confidence he had in me and for the unconditional support I received from him. Dr. Gautam I am grateful to you for fulfilling the irresistible offer. I am grateful to Daniel Carder for what he has taught me and the experience of learning from him, be it engines, emissions, work ethics, building PCs and much more. Hey Dan thanks for hooking me up with American football, a great pastime, and inviting me over to watch the playoffs. I would like to thank Dr. Gregory Thompson and Dr. Scott Wayne for being on my committee. I admire Dr Thompson for his organization and time management skills. I am thankful to Dr Wayne for providing the flow rate and temperature data when it was needed very much. Thanks are due to Tom Long Jr., Ted Christian, Curt Leasor and Chris Rowe. Chris is the man who made things a reality, if it was not for him it would have taken a week or more to complete the testing. Special thanks to Bobby John for taking the responsibility of particle size measurements. I would like to thank Tom Spencer, Ben Shade, Wesley Riddle, Richard Atkinson and Ron Jarett for all the technical help I received from them while working at EERC, Sabraton and Westover. I would like to thank my contemporaries Sam George, Gurudutt, Aseem, Vinay, Sairam, Michelangelo, Rafaello, Karthik, Shashi, Ravi, and Aaron for giving a great company all along my master's career. I am ever grateful to my dearest mom and dad for the sacrifices they have made to make me what I am today and the values of life they have taught me. I would like to thank my sister Latha Suresh and my brother in-law Dr. H.N. Suresh, I still cannot believe that you made me leave my beloved Bangalore for US and I am ever thankful for transferring me from deep well to an ocean. Bhavana and the little Bhanavee please forgive me for not being there to play with you girls. I am thankful to Dr. Haritha and Dr. Chandraprabha for treating me as their family member and gifting me an untiring Toyota Camry. I would like to remember my late brother Ravi Kumar and dedicate my career to him. iii TABLE OF CONTENTS ABSTRACT....................................................................................................................... ii ACKNOWLEDGEMENTS ............................................................................................iii TABLE OF CONTENTS ................................................................................................ iv LIST OF TABLES .......................................................................................................... vii TABLE OF FIGURES..................................................................................................... ix NOMENCLATURE........................................................................................................ xii 1 INTRODUCTION................................................................................................... 1 1.1 Introduction............................................................................................................. 1 1.2 Objective................................................................................................................. 4 2 LITERATURE REVIEW....................................................................................... 6 2.1 California Urban Bus Emissions Regulation .......................................................... 6 2.2 Natural Gas as Fuel................................................................................................. 9 2.3 Significance of Different Emission Components ................................................. 10 2.4 Previous Studies Comparing Emissions Between Diesel and CNG Engines....... 16 2.4.1 CARB Study................................................................................................. 16 2.4.2 TNO Automotive Study, Netherlands........................................................... 18 2.4.3 International School Bus Study .................................................................... 19 2.4.4 The Finnish National Bus Project................................................................. 20 2.5 CNG Engine Design Enhancement....................................................................... 22 2.6 Chemical Speciation............................................................................................. 23 2.7 Aftertreatment Devices........................................................................................