Engine Exhaust Particulates

Avinash Kumar AgarwalAtul DharNikhil SharmaPravesh Chandra Shukla Editors

Energy, Environment, and SustainabilitySeries Editors: Avinash Kumar Agarwal · Ashok Pandey

Energy, Environment, and Sustainability

Series editors

Avinash Kumar Agarwal, Department of Mechanical Engineering, Indian Instituteof Technology Kanpur, Kanpur, Uttar Pradesh, IndiaAshok Pandey, Distinguished Scientist, CSIR-Indian Institute of ToxicologyResearch, Lucknow, Uttar Pradesh, India

This books series publishes cutting edge monographs and professional booksfocused on all aspects of energy and environmental sustainability, especially as itrelates to energy concerns. The Series is published in partnership with theInternational Society for Energy, Environment, and Sustainability. The books inthese series are editor or authored by top researchers and professional across theglobe. The series aims at publishing state-of-the-art research and development inareas including, but not limited to:

• Renewable Energy• Alternative Fuels• Engines and Locomotives• Combustion and Propulsion• Fossil Fuels• Carbon Capture• Control and Automation for Energy• Environmental Pollution• Waste Management• Transportation Sustainability

More information about this series at http://www.springer.com/series/15901

Avinash Kumar AgarwalAtul Dhar • Nikhil SharmaPravesh Chandra ShuklaEditors

Engine Exhaust Particulates

123

EditorsAvinash Kumar AgarwalDepartment of Mechanical EngineeringIndian Institute of Technology KanpurKanpur, Uttar Pradesh, India

Atul DharSchool of EngineeringIndian Institute of Technology MandiMandi, Himachal Pradesh, India

Nikhil SharmaDepartment of Mechanical EngineeringIndian Institute of Technology KanpurKanpur, Uttar Pradesh, India

Pravesh Chandra ShuklaDepartment of Mechanical EngineeringIndian Institute of Technology BhilaiBhilai, Chhattisgarh, India

ISSN 2522-8366 ISSN 2522-8374 (electronic)Energy, Environment, and SustainabilityISBN 978-981-13-3298-2 ISBN 978-981-13-3299-9 (eBook)https://doi.org/10.1007/978-981-13-3299-9

Library of Congress Control Number: 2018961730

© Springer Nature Singapore Pte Ltd. 2019This work is subject to copyright. All rights are reserved by the Publisher, whether the whole or partof the material is concerned, specifically the rights of translation, reprinting, reuse of illustrations,recitation, broadcasting, reproduction on microfilms or in any other physical way, and transmissionor information storage and retrieval, electronic adaptation, computer software, or by similar or dissimilarmethodology now known or hereafter developed.The use of general descriptive names, registered names, trademarks, service marks, etc. in thispublication does not imply, even in the absence of a specific statement, that such names are exempt fromthe relevant protective laws and regulations and therefore free for general use.The publisher, the authors and the editors are safe to assume that the advice and information in thisbook are believed to be true and accurate at the date of publication. Neither the publisher nor theauthors or the editors give a warranty, express or implied, with respect to the material contained herein orfor any errors or omissions that may have been made. The publisher remains neutral with regard tojurisdictional claims in published maps and institutional affiliations.

This Springer imprint is published by the registered company Springer Nature Singapore Pte Ltd.The registered company address is: 152 Beach Road, #21-01/04 Gateway East, Singapore 189721,Singapore

Preface

Energy demand has been rising remarkably due to increasing population andurbanization. Global economy and society are significantly dependent on the energyavailability because it touches every facet of human life and its activities.Transportation and power generation are two major examples. Without the trans-portation by millions of personalized and mass transport vehicles and availability of24 � 7 power, human civilization would not have reached contemporary livingstandards.

The International Society for Energy, Environment and Sustainability (ISEES)was founded at Indian Institute of Technology Kanpur (IIT Kanpur), India, inJanuary 2014 with the aim of spreading knowledge/awareness and catalysingresearch activities in the fields of energy, environment, sustainability and com-bustion. The society’s goal is to contribute to the development of clean, affordableand secure energy resources and a sustainable environment for the society and tospread knowledge in the above-mentioned areas and create awareness about theenvironmental challenges, which the world is facing today. The unique wayadopted by the society was to break the conventional silos of specializations(engineering, science, environment, agriculture, biotechnology, materials, fuels,etc.) to tackle the problems related to energy, environment and sustainability in aholistic manner. This is quite evident by the participation of experts from all fieldsto resolve these issues. ISEES is involved in various activities such as conductingworkshops, seminars and conferences in the domains of its interest. The society alsorecognizes the outstanding works done by the young scientists and engineers fortheir contributions in these fields by conferring them awards under variouscategories.

The second international conference on “Sustainable Energy and EnvironmentalChallenges” (SEEC-2018) was organized under the auspices of ISEES from 31December 2017 to 3 January 2018 at J N Tata Auditorium, Indian Institute ofScience Bangalore. This conference provided a platform for discussions betweeneminent scientists and engineers from various countries including India, USA,South Korea, Norway, Finland, Malaysia, Austria, Saudi Arabia and Australia. Inthis conference, eminent speakers from all over the world presented their views

v

related to different aspects of energy, combustion, emissions and alternative energyresources for sustainable development and a cleaner environment. The conferencepresented five high-voltage plenary talks from globally renowned experts on topicalthemes, namely “Is It Really the End of Combustion Engines and Petroleum?” byProf. Gautam Kalghatgi, Saudi Aramco; “Energy Sustainability in India:Challenges and Opportunities” by Prof. Baldev Raj, NIAS Bangalore; “MethanolEconomy: An Option for Sustainable Energy and Environmental Challenges” byDr. Vijay Kumar Saraswat, Hon. Member (S&T), NITI Aayog, Government ofIndia; “Supercritical Carbon Dioxide Brayton Cycle for Power Generation” by Prof.Pradip Dutta, IISc Bangalore; and “Role of Nuclear Fusion for EnvironmentalSustainability of Energy in Future” by Prof. J. S. Rao, Altair Engineering.

The conference included 27 technical sessions on topics related to energy andenvironmental sustainability including 5 plenary talks, 40 keynote talks and 18invited talks from prominent scientists, in addition to 142 contributed talks, and 74poster presentations by students and researchers. The technical sessions in theconference included Advances in IC Engines: SI Engines, Solar Energy: Storage,Fundamentals of Combustion, Environmental Protection and Sustainability,Environmental Biotechnology, Coal and Biomass Combustion/Gasification, AirPollution and Control, Biomass to Fuels/Chemicals: Clean Fuels, Advances in ICEngines: CI Engines, Solar Energy: Performance, Biomass to Fuels/Chemicals:Production, Advances in IC Engines: Fuels, Energy Sustainability, EnvironmentalBiotechnology, Atomization and Sprays, Combustion/Gas Turbines/FluidFlow/Sprays, Biomass to Fuels/Chemicals, Advances in IC Engines: NewConcepts, Energy Sustainability, Waste to Wealth, Conventional and AlternateFuels, Solar Energy, Wastewater Remediation and Air Pollution. One of thehighlights of the conference was the rapid-fire poster sessions in (i) EnergyEngineering, (ii) Environment and Sustainability and (iii) Biotechnology, wheremore than 75 students participated with great enthusiasm and won many prizes in afiercely competitive environment. More than 200 participants and speakers attendedthis four-day conference, which also hosted Dr. Vijay Kumar Saraswat, Hon.Member (S&T), NITI Aayog, Government of India, as the chief guest for the bookrelease ceremony, where 16 ISEES books published by Springer, Singapore, undera special dedicated series “Energy, Environment, and Sustainability” were released.This is the first time that such significant and high-quality outcome has beenachieved by any society in India. The conference concluded with a panel discussionon “Challenges, Opportunities & Directions for Future Transportation Systems”,where the panellists were Prof. Gautam Kalghatgi, Saudi Aramco; Dr. RaviPrashanth, Caterpillar Inc.; Dr. Shankar Venugopal, Mahindra and Mahindra; Dr.Bharat Bhargava, DG, ONGC Energy Center; and Dr. Umamaheshwar, GETransportation, Bangalore. The panel discussion was moderated by Prof. AshokPandey, Chairman, ISEES. This conference laid out the road map for technologydevelopment, opportunities and challenges in energy, environment and sustain-ability domains. All these topics are very relevant for the country and the world inthe present context. We acknowledge the support received from various fundingagencies and organizations for the successful conduct of the second ISEES

vi Preface

conference SEEC-2018, where these books germinated. We would therefore like toacknowledge SERB, Government of India (special thanks to Dr. Rajeev Sharma,Secretary); ONGC Energy Center (special thanks to Dr. Bharat Bhargava); TAFE(special thanks to Sh. Anadrao Patil); Caterpillar (special thanks to Dr. RaviPrashanth); Progress Rail, TSI, India (special thanks to Dr. Deepak Sharma);Tesscorn, India (special thanks to Sh. Satyanarayana); GAIL, Volvo; and ourpublishing partner Springer (special thanks to Swati Mehershi).

The editors would like to express their sincere gratitude to a large number ofauthors from all over the world for submitting their high-quality work in a timelymanner and revising it appropriately at short notice. We would like to express ourspecial thanks to Dr. Tapan Kumar Pradhan, Dr. Atul Dhar, Dr. Akhilendra PratapSingh, Dr. Ludovica Luise, Dr. Joonsik Hwang, Dr. Chetan Patel, Dr. PraveshChandra Shukla, Dr. Sundeep Singh, Dr. Rohit Singla, Dr. Rajesh Prasad, Dr.Vikram Kumar, Dr. Dev Prakash Satsangi, Dr. Anoop Kumar Shukla, Mr. ManeeshKumar, Mr. Neeraj Sharma, Mr. Sunil Kumar, Mr. Yeshudas Jiotode and Mr.Pawan Kumar, who reviewed various chapters of this book and provided veryvaluable suggestions to the authors to improve their manuscript.

This book covers different aspects of both diesel and gasoline engine particu-lates. The first half of this book is about diesel engine particulates, and the secondhalf of this book is about gasoline engine particulates. This book provides acomprehensive insight into the motor vehicles’ particulates, its formation andcomposition, location of particulates, measurement, characterization and toxicol-ogy. This book also focuses on exhaust after-treatment devices and their compar-ison. Apart from this, the effect of engine design and operation variables, emissionlegislation and emission measurement are presented. Engine exhaust after-treatmentconcepts such as HC adsorbed systems, NO traps and advanced engines like RCCI,GDI and HCCI engines are covered in this book. The text in every chapter iscomplemented by illustrations and is written by field expert.

Kanpur, India Avinash Kumar AgarwalAtul Dhar

Nikhil SharmaPravesh Chandra Shukla

Preface vii

Contents

Part I General

1 Introduction to Engine Exhaust Particulates . . . . . . . . . . . . . . . . . . 3Avinash Kumar Agarwal, Atul Dhar, Nikhil Sharmaand Pravesh Chandra Shukla

2 Ultrafine Particles in Concern of Vehicular Exhaust—AnOverview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7Shailendra Kumar Yadav, Rajeev Kumar Mishraand Bhola Ram Gurjar

Part II Diesel Particulates

3 Image-Based Flame Temperature and Soot Analysis of BiofuelSpray Combustion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41Joonsik Hwang, Felix Sebastian Hirner, Choongsik Bae,Chetankumar Patel, Tarun Gupta and Avinash Kumar Agarwal

4 Characteristics and Fundamentals of Particulates in DieselEngine . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55Khawar Mohiuddin and Sungwook Park

5 Numerical Modelling of Soot in Diesel Engines . . . . . . . . . . . . . . . . 71Pavan Prakash Duvvuri, Rajesh Kumar Shrivastavaand Sheshadri Sreedhara

6 Physico-chemical Properties of Diesel Exhaust Particulates . . . . . . 121Jianbing Gao and Guohong Tian

Part III Alternate Fuel Origin Particulates

7 Oxygenated Fuel Additive Option for PM Emission Reductionfrom Diesel Engines—A Review . . . . . . . . . . . . . . . . . . . . . . . . . . . 141Parameswaran Vijayashree and V. Ganesan

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8 Technological Evolution of Spark Ignition Direct InjectionEngine . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 165Nikhil Sharma and Avinash Kumar Agarwal

9 Alternative Fuels for Particulate Control in CI Engines . . . . . . . . . 181Sam Shamun, Pablo Garcia and Erik Svensson

10 Particulate Emissions from Hydrogen Diesel FuelledCI Engines . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 199Priybrat Sharma and Atul Dhar

Part IV Gasoline Particulates

11 Particulate Emission from Gasoline Direct Injection Engine . . . . . . 215Ludovica Luise

12 Nanoparticle Emissions in Reactivity-Controlled CompressionIgnition Engine . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 239Mohit Raj Saxena and Rakesh Kumar Maurya

x Contents

Editors and Contributors

About the Editors

Avinash Kumar Agarwal is Professor in theDepartment of Mechanical Engineering at IndianInstitute of Technology Kanpur. His areas of interestare IC engines, combustion, alternative fuels, conven-tional fuels, optical diagnostics, laser ignition, HCCI,emission and particulate control, and large boreengines. He has published 24 books and more than230 international journal and conference papers. He isFellow of SAE (2012), ASME (2013), ISEES (2015)and INAE (2015). He has received several awards suchas the prestigious Shanti Swarup Bhatnagar Award inengineering sciences (2016), Rajib Goyal Prize (2015)and NASI-Reliance Industries Platinum Jubilee Award(2012).

Atul Dhar has been Assistant Professor at IIT Mandisince 2013. He received his M.Tech. and Ph.D. fromthe Department of Mechanical Engineering, IITKanpur, in 2006 and 2013, respectively. He wasawarded the European Union Erasmus MundusFellowship in 2013 and the Young Scientist Awardfrom the International Society for Energy, Environmentand Sustainability in 2015. He has edited 3 books andpublished 12 chapters and more than 35 internationalpeer-reviewed journal papers.

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Nikhil Sharma is Scientist at the Engine ResearchLaboratory, IIT Kanpur, India. He received his M.Tech.in mechanical engineering from NIT Hamirpur, India,in 2012, and his Ph.D. from IIT Kanpur in 2017.He was former Assistant Professor at Amity Uni-versity’s Department of Mechanical and AutomationEngineering, Noida. His areas of research includealternative fuels for IC engines (biodiesel, alcohols),emission control and particulate characterization.

Pravesh Chandra Shukla is Assistant Professor in theDepartment of Mechanical Engineering, IIT Bhilai.After completing his Ph.D. at IIT Kanpur, he worked asa postdoc at Lund University, Sweden. His researchinterests include internal combustion engines, alterna-tive fuels (biodiesel, alcohols, HVO), diesel emissionsand their control, unregulated emissions from dieseland gasoline engines, after-treatment devices and fuelspray and its characterization. He has authored 25research publications and 2 chapters.

Contributors

Avinash Kumar Agarwal Engine Research Laboratory, Department ofMechanical Engineering, Indian Institute of Technology Kanpur, Kanpur, India

Choongsik Bae Department of Mechanical Engineering, Korea AdvancedInstitute of Science and Technology, Daejeon, Republic of Korea

Atul Dhar School of Engineering, Indian Institute of Technology Mandi, Mandi,India

Pavan Prakash Duvvuri Department of Energy Science and Engineering, IndianInstitute of Technology Bombay, Mumbai, India; Combustion Research, CumminsTechnical Center India, Pune, India

V. Ganesan Department of Mechanical Engineering, Indian Institute ofTechnology Madras, Chennai, India

xii Editors and Contributors

Jianbing Gao University of Surrey, Surrey, UK

Pablo Garcia Lund University, Lund, Sweden

Tarun Gupta Department of Civil Engineering, Indian Institute of TechnologyKanpur, Kanpur, India

Bhola Ram Gurjar Centre for Transportation System, Indian Institute ofTechnology Roorkee, Roorkee, India

Felix Sebastian Hirner Department of Mechanical Engineering, Korea AdvancedInstitute of Science and Technology, Daejeon, Republic of Korea

Joonsik Hwang Department of Mechanical Engineering, Korea AdvancedInstitute of Science and Technology, Daejeon, Republic of Korea; CombustionResearch Facility (CRF), Sandia National Laboratories, Albuquerque, USA

Ludovica Luise Oxford Brookes University, Oxford, UK

Rakesh Kumar Maurya Advanced Engine and Fuel Research Laboratory,Department of Mechanical Engineering, Indian Institute of Technology Ropar,Punjab, India

Rajeev Mishra Department of Environmental Engineering, Delhi TechnologicalUniversity, New Delhi, India

Khawar Mohiuddin Department of Mechanical Convergence Engineering,Graduate School of Hanyang University, Seoul, Republic of Korea

Sungwook Park School of Mechanical Engineering, Hanyang University, Seoul,Republic of Korea

Chetankumar Patel Department of Mechanical Engineering, Indian Institute ofTechnology Kanpur, Kanpur, India

Mohit Raj Saxena Advanced Engine and Fuel Research Laboratory, Departmentof Mechanical Engineering, Indian Institute of Technology Ropar, Punjab, India

Nikhil Sharma Engine Research Laboratory, Department of MechanicalEngineering, Indian Institute of Technology Kanpur, Kanpur, India

Priybrat Sharma School of Engineering, Indian Institute of Technology Mandi,Mandi, India

Rajesh Kumar Shrivastava Combustion Research, Cummins Technical CenterIndia, Pune, India

Pravesh Chandra Shukla Department of Mechanical Engineering, IndianInstitute of Technology Bhilai, Bhilai, India

Editors and Contributors xiii

Sam Shamun Lund University, Lund, Sweden

Sheshadri Sreedhara Department of Mechanical Engineering, Indian Institute ofTechnology Bombay, Mumbai, India

Erik Svensson Lund University, Lund, Sweden

Guohong Tian University of Surrey, Surrey, UK

Vijayashree Department of Mechanical Engineering, Indian Institute ofTechnology Madras, Chennai, India

Shailendra Kumar Yadav Department of Environmental Engineering, DelhiTechnological University, New Delhi, India

xiv Editors and Contributors

Part IGeneral

Chapter 1Introduction to Engine ExhaustParticulates

Avinash Kumar Agarwal, Atul Dhar, Nikhil Sharmaand Pravesh Chandra Shukla

Abstract Emission legislations are getting stringent throughout the word andresearchers/OEMs are working to meet these challenging emission norms. Thisbook covers different aspects of diesel and gasoline engine particulates. The topicsprovide a comprehensive insight into motor vehicle origin particulates, its forma-tion, and composition, measurement, characterization and toxicology. This bookalso focuses on exhaust gas after-treatment devices with emphasis on some basicaspects. Apart from this, particulate emissions from alternative fuels have also beenincluded in this book. The text in every chapter is complemented by illustrationsand is written by domain experts. Overall, this book covers a wide range of topicrelated to engine exhaust particles and will be of interest to established researchersin the field as well as upcoming researchers. The topics are organized in threedifferent sections, namely, (i) general, (ii) diesel particulates, (iii) alternate fuelorigin particulates.

Keywords Diesel engine particulates � Gasoline engine particulatesAlternative fuels � RCCI

A. K. Agarwal (&) � N. SharmaEngine Research Laboratory, Department of Mechanical Engineering,Indian Institute of Technology Kanpur, Kanpur, Indiae-mail: akag@iitk.ac.in

A. DharSchool of Engineering, Indian Institute of Technology Mandi, Mandi, India

P. C. ShuklaDepartment of Mechanical Engineering, Indian Institute of Technology Bhilai,Bhilai, India

© Springer Nature Singapore Pte Ltd. 2019A. K. Agarwal et al. (eds.), Engine Exhaust Particulates, Energy, Environment,and Sustainability, https://doi.org/10.1007/978-981-13-3299-9_1

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1.1 Introduction

There is a growing consensus amongst health experts all over the world that theparticles in nano- and ultra-fine range (<100 nm diameter) have relatively higheradverse effect on the human health. First part of the book comprises generalintroduction, which includes two chapters. First chapter is introduction and thesecond chapter is based on ultra-fine particles. Around the world, researchers areworking on vehicles with advanced technology, both gasoline and diesel fuelled.This chapter covers ultra-fine particulate matter (UFPs) emissions, process of for-mation, physico-chemical characteristics, fate of particulate transport and theirhealth impact. A section of this chapter highlights the needs for future research onUFPs.

The second part of the book is specific to diesel particulates, which includes fourchapters. The very first chapter in this section is related to image-based flametemperature and soot analysis of biofuel spray combustion. In this chapter, animage-based temperature and soot analysis were introduced and applied to sprayflames of biodiesel and diesel combustion in a constant volume combustionchamber. The second chapter is related to characteristics and fundamentals ofparticulates from diesel engines. This chapter covers the basics of soot emissionfrom CI engines and composition of soot along with its structure. Fundamentals ofparticle formation, oxidation, adsorption and condensation of soot have been dis-cussed in the later part of this chapter. Soot in the CI engines is produced due tofuel-rich combustion. The third chapter of this section is related to numericalmodelling of soot in diesel engines. Numerical modelling of soot in diesel engineshas evolved over four decades from simple empirical correlations to complexaerosol dynamics and detailed kinetics. This chapter presents a brief overview ofmodelling the soot in diesel engines. This chapter starts with a description ofphysical and chemical processes involved in soot formation, namely, gas-phasekinetics, nucleation, surface reactions and coagulation. The fourth chapter of thissections deals with physico-chemical properties of diesel exhaust particulates. Itsuggests that diameter of diesel PM is smaller than 1 lm that could be easilyinhaled into respiratory system. The PM diameter is smaller if turbocharger andcommon rail are used. The formation mechanism of diesel PM is complex, and thecylinder combustion conditions have a huge effect on PM physico-chemicalproperties. In this chapter, the detailed analysis of diesel PM physico-chemicalproperties is made, such as particulate ingredients, diameter and mass distributions,microstructures and oxidation behaviours. Diesel PM mainly contains soot, solubleorganic fraction and ash whose percentages change with PM formation conditions,such as engine load and speed, engine type and fuel type. The researches onmicrostructures and oxidation behaviour make the foundation of decreasing PMemission and optimizing particulate after-treatment devices.

The third section of the book comprises alternate fuel origin particulates, whichincludes six chapters. The first chapter of this section comprehensively reviews theoxygenated fuel additives for sustainable emission reduction from diesel engines.

4 A. K. Agarwal et al.

In this chapter, authors embark on the analysis and review of the application ofoxygenated alternative fuels such as biodiesel, acetone–butanol–ethanol(ABE) solution and water emulsion as oxygenated fuel reformulation strategies.Attention was focused to precisely bring out the effect of ABE to reduce mostemissions. Further, various fuel properties of these kinds of fuels should be eval-uated accurately and should be made available to researchers so that increase/decrease in emissions of NOx, PM, CO, HC, PAHs and POPs can be accuratelyestablished. This can be done at national and international levels with the support ofgovernments. Transport sector is an important factor for economic development ofa country. The second chapter of this section is related to evolution, particulateemissions and morphological characteristics of spark ignition direct injectionengine. Morphology and particle number (PN)/PM emission w.r.t. gasohol arediscussed in this chapter. This chapter also makes a comparative analysis of GDIversus PFI concepts. A detailed discussion on PM formation and emission from aGDI engine is discussed. Overall, this chapter gives some basic understanding ofGDI engine and emission formation and control techniques. In comparison to sparkignition (SI) engine, the compression ignition (CI) engines produce relativelyhigher engine-out particulate matter (PM) emissions. The third chapter in thissection is related to alternative fuels for particulate control in CI engines. The factthat diesel combustion in CI engines is highly stratified promotes the production ofPM with a high particulate number (PN). Since NOx emissions from this com-bustion strategy are another major drawback, exhaust gas recirculation (EGR) iswidely used to reduce these emissions. Fourth chapter of this section is related toparticulate emissions from hydrogen diesel fuelled CI engines. Compression igni-tion engines are much-celebrated power plants for both heavy transport and sta-tionary applications, owing to their high thermal efficiency and high values oflow-speed torque. However, CI engines are infamous for emission of black smoke,mostly composed of soot/particulates. The prime effect of hydrogen addition ondiesel particulate emissions is reduction of carbon content in the fuel mixture due todilution effect. The reduction of carbon, which is the main constituent of soot, leadsto a reduction of PM emissions as compared to a baseline diesel engine. The fifthchapter of this section is related to particulate emissions from GDI engines.Relatively higher volumetric efficiency as well as better charge cooling helpsincrease the effective compression ratios of these engines, hence increasing theoverall brake thermal efficiency. This chapter gives a general overview of howparticulates are formed inside the GDI engines and the main parameters that affecttheir formation during combustion. Soot emissions along with other possibleparameters affecting it are discussed. The last chapter of this section is related tonanoparticle emissions in reactivity controlled compression ignition (RCCI) engine.Relatively smaller size particles having diameter typically *20 nm dominate inRCCI combustion regime. This chapter summarizes the concept, benefits andlimitations of RCCI combustion regime. This chapter deals with the particulateemission characteristics of RCCI engines. RCCI combustion is a potential alter-native technology to meet the Euro-VI norms along with higher thermal efficiency.

1 Introduction to Engine Exhaust Particulates 5

Overall, this book covers a wide range of topics related to engine exhaustparticles and will be of interest to researchers in the field. Specific topics covered inthis book include the following:

1. Introduction to engine exhaust particulates,2. Ultra-fine particles in concern of vehicular exhaust—an overview,3. Image-based flame temperature and soot analysis of biofuel spray combustion,4. Characteristics and fundamentals of particulates in diesel engine,5. Numerical modelling of soot in diesel engines,6. Physico-chemical properties of diesel exhaust particulates,7. Oxygenated fuel additive option for pm emission reduction from diesel engines

—a review,8. Technological evolution of spark ignition direct injection engine,9. Alternative fuels for particulate control in CI engines,

10. Particulate emissions from hydrogen diesel fuelled CI engines,11. Particulate emission from gasoline direct injection engines,12. Nanoparticle emissions in reactivity controlled compression ignition engine.

6 A. K. Agarwal et al.

Chapter 2Ultrafine Particles in Concernof Vehicular Exhaust—An Overview

Shailendra Kumar Yadav, Rajeev Kumar Mishraand Bhola Ram Gurjar

Abstract There is a growing consensus among health experts all over the worldthat the particles in nano- and ultrafine range (<100 nm diameter) are having sig-nificant vulnerable effect on the human health regarding carcinogenicity and car-diovascular diseases. Worldwide experimental study on the vehicles with advancedtechnology, both gasoline and diesel, shows reduction in PM mass but increasedparticle number mainly in the ultrafine range known as the ultrafine particles(UFPs). Hence, characterization of particulates in terms of their size distribution andnumber is of great importance for the vehicles operating on different fuels and awide range of technology spectrum. New emission regulations, Euro V and Euro VIimplemented in Europe, which are likely to get harmonized in India, will cover onlydiesel and gasoline direct injection engines. UFPs are emitted from almost everyfuel combustion process, including diesel, gasoline, and jet engines, as well asexternal combustion processes such as burning of woods, coal, and other naturalphenomena like forest fires. Consequently, there is growing concern that peopleliving in close proximity to highly trafficked roadways and other sources ofcombustion-related pollutants (airports and rail yards) may be exposed to significantlevels of UFPs and other air toxics. This chapter covers the UFPs process offormation, physiochemical characteristics, the fate of transportation, and healthimpact. The last section of this chapter highlights mainly about the needs of thefuture research on UFPs.

S. K. Yadav � R. K. Mishra (&)Department of Environmental Engineering, Delhi Technological University,New Delhi, Indiae-mail: rajeevmishraiitr@gmail.com

S. K. Yadave-mail: skkky_envirph123@yahoo.com

B. R. GurjarCentre for Transportation System, Indian Institute of Technology Roorkee,Roorkee, Indiae-mail: bholafce@iitr.ac.in

© Springer Nature Singapore Pte Ltd. 2019A. K. Agarwal et al. (eds.), Engine Exhaust Particulates, Energy, Environment,and Sustainability, https://doi.org/10.1007/978-981-13-3299-9_2

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Keywords Air pollution � Ultrafine particles (UFPs) � Formation processParticle size distribution � Transport � Heath impact

2.1 Introduction

Particulate matter (PM) has been noted for a long time as an atmospheric pollutant.Even, the residents of ancient Rome were aware of “pestilential vapor and roadsoot” problem which is now referred to as air pollution (Kahl et al. 1997). Before1950, the terminology particulate matter had a meaning of large diameter, generatedfrom coal combustion from industrial activities and home heating, most of the effortthat time was to acquire the control of fuel modification technology with some focusregarding particle measurements (Mishra et al. 1974). In the 1950s and early 1960sdue to the approach of the radioactive aftermath from the ground atomic test in theUnited States and abroad, the harmful and toxic effects of PM rose to a greater levelwhich resulted in the immediate human health-related problems. Later in the periodof 1960s and 1970s, the speedy process of policy and technological interventionslead to the eventual improvement in air quality. With the advancement in scienceand technology, the measurement techniques of air pollution improved and itsadverse impact on human health’s properties evolved, which led to the assessmentof people’s health, and the physicochemical properties of particulate matter becamea larger issue for health workers, scientists, and policymakers. Therefore, thetechnology is needed to include the ability to measure particle size and concen-tration at elaborative levels of detection and the power to detect human health riskassessment (Mishra et al. 1974; Hester et al. 2016).

The term “Particulate Matter” is generally used to point out the combination ofaerosol (liquid droplet) and solid particles that differ in size. Aerodynamic diameter,surface area, the type of fuel used, conditions of ambient temperature, combustiontemperature, and composition of particulates are the factors affecting the size ofparticulate matter which mainly depend upon the time and location of that particulararea. Particles may include elemental (black) and organic carbon compounds,sulfates (SO4

2�) and nitrates (NO3�), soil particles (crustal material), trace metals,

and sea salt also with different ratios (Harrison et al. 1998; Coburn 2000).Now particulate matter has categorized in different size ranges of diameter with

the improvement of measurement technology (PM10 � 10 µm, PM2.5 � 2.5 µm,Fine Particle � 0.1 µm, UFPs � 100 nm, and nanoparticle � 30 nm) (Hesteret al. 2016).

The word “diameter” is broadly used to describe particle size, but particles areinfrequently spherical with single diameter, so in this concern, Honey and McQuitty(1976) refer to eight distinct measures of particle size. Generally, the most useful is“aerodynamic diameter” (Dey et al. 2012).

8 S. K. Yadav et al.

Generally, PM10 and PM2.5 are measured in the “mass concentration” basis butin case of ultrafine and nanoparticles (due to their negligible mass), they aremeasured based on the particle number per unit volume as particle number per cm3

(PNC) (Baldauf et al. 2016). Therefore, different sizes of particulate matter can bealso classified into the following way: PM10 (as thoracic fraction � 10 µm), PM2.5

(as respirable fraction � 2.5 µm), PM1 (alveolar fraction � 1 µm), and ultra-fine � 0.1 µm. PM10 and PM2.5 combinedly known as coarse particle (coarsefraction) (Air Quality Science 2011).1

On April 30, 1971, Environmental Protection Agency (EPA) established theNational Ambient Air Quality Standard (NAAQS) in which total suspended particle(TSP) was a standard for particulate matter as an indicator after getting proper linkbetween particulate matter and its adverse impact on human health and property.According to the first periodic review of NAAQS in 1981, TSP was changed toPM10 as an indicator of particulate matter’s estimation. Later in 1997, PM2.5 asparameter was added to NAAQS in the second review. Because EPA’s concern wasthat PM-NAAQS should focus on particle size which is lesser than or equal to PM10

and PM2.5, it should be considered separately, which demonstrated that the sub-group of inhalable particles is small enough to penetrate/pass through the thoracicregion (the tracheobronchial and alveolar region) of the respiratory tract.EPA-NAAQS review aimed to improve the NAAQS for particulate matter. Thismodification was based on the evidence of health issues related to the exposure(short and long term) of fine particles in areas that already meeting the existingPM10 standard.

2

Till now, there are no such standard criteria to make the ultrafine particulatematter as an indicator. In the 2006 workshop on air pollution by WHO, ultrafineattracted a lot of attention and base level work (Baldauf et al. 2016) (Table 2.1).3

2.2 Fundamental of Particle Emission from Engine

With the start of the evolution, the first trade-off between the utility and amenityarose with fire, but what proved to be the greatest of all was the rise of the industrialrevolution. But this was the beginning of all the reasons responsible for thedegradation of ambient air with an increase in the emission sources. Smokeemission from motor vehicles proved to be the major concern for the rise in airpollution. This resulted in overall changes in temperature and disturbed the airequilibrium of the Earth, which resulted in global warming and other health-relatedissues. The smoke released from the vehicular exhaust and its sheer visibility,coupled with malodorous emission, proved to be irritant to eyes and nose, thus

1Review DL Health Impacts of Ultrafine Particles.2Integrated Review Plan for the National Ambient Air Quality Standards for Particulate Matter.3Coast S, Quality A, District M Chapter 2 Air Quality and Health Effects.

2 Ultrafine Particles in Concern of Vehicular Exhaust … 9

becoming a major concern (Eastwood 2008). There are three types of emissionsfrom engines which are exhaustive means substances that come out of an exhaustsystem into the atmosphere, evaporative emission means evaporation of gasolinevapors from the fuel tank and fuel system, whereas crankcase emission formulationof emission particles by unburnt, compressed air/fuel mixture entering the crank-case from the combustion area. To control these emissions, technological imple-mentations have been like catalytic converter which converts toxic gases andpollutants generating from internal combustion into less toxic pollutants by cat-alyzing a redox reaction. The other method is charcoal canister which involvesusing a part of evaporative emission control system (EVAP). Its ultimate roleincludes absorbing fuel vapors from the vent and later releasing it back into engine

Table 2.1 Summary of national ambient air quality standard promulgated for particulate matter(www.epa.gov/pm-pollution/table-historical-particulate-matter-pm-national-ambient-air-quality-standards-naaqs)

Finalrule

Indicator Ave.time

Level From

1971 TSP (totalsuspendedparticles) � 25–45 lm

24-h 260 lm/gm3 (primary)150 lm/gm3

(secondary)

Not to be exceeded more thanonce per year

Annual 75 lm/gm3 (primary) Annual average

1987 PM10 24-h 150 lm/gm3 Not to be exceeded more thanonce per year on average over a3-year period

Annual 50 lm/gm3 Annual arithmetic mean,averaged over 3 years

1997 PM2.5 24-h 65 lm/gm3 98th percentile, averaged over3 years

Annual 15 lm/gm3 Annual arithmetic mean,averaged over 3 years

PM10 24-h 150 lm/gm3 Initially promulgated 99thpercentile, averaged over3 years, when 1997 standardswere vacated the form of 1987standards remained in place (notto be exceeded more than onceper year, on average over3 years

Annual 50 lm/gm3 Annual arithmetic mean,averaged over 3 years

2006 PM2.5 24-h 35 lm/gm3 98th percentile, averaged over3 years

Annual 15 lm/gm3 Annual arithmetic mean,averaged over 3 years

PM10 24-h 150 lm/gm3 Not to be exceeded more thanonce a year, on average over a3-year period

10 S. K. Yadav et al.

through the purge valve and then burned. The last method includes the use ofpositive crankcase ventilation (PCV) device with its aim of reducing the harmfulvapors from the crankcase of the engine (ocregister.com 2008; GammaTechnologies 2018; Kathuria 2002).

2.2.1 Combustion of Vehicles Fuel and Emission Exhaust

An engine combustion is a process of exothermic chemical reactions in which rapidoxidation of fuel substance occurs with liberation of heat energy at a faster rate thanits dissipation by transport process (convection, radiation, and conduction). Asshown in Fig. 2.1 “Particulate Emission from Motors,” there are four input com-ponents in concern of particulate formation within engine: Fuel, lubricant oil, air,and material disintegration. Ash and carbonaceous mostly generated within theengine during the combustion process, but other fractions (organic fraction, Sulfatefraction, and nitrate fraction) generated within the exhaust system of motor vehi-cles. In the broader sense, fuel and lubricant oil may be the source of all above-mentioned fractions in different ratios of composition, but air and materialdisintegration may be general sources of ash fraction in the engine. So, in concernof Engine Exhaust, it can be arranged by the following descending order:

Fuel[Lubricant[Air[Material Disintegration

The combination of the combustion process, premixed flame, diffusion flameand ignition delay with fuel spray along with an air mixture, starts the particulatematter formation in different sizes and chemical composition ranges. Endothermicchemical reaction with high temperature with a low oxygen concentration promotesthe “pyrolysis” phenomena. Carbonaceous fraction or soot is generated with help ofpyrolysis process, but, compared to the absence of oxygen, insufficient amount ofoxygen is more suitable to sensitize the soot formation through pyrolysis. Highcombustion temperature generates lower molecular weight carbonaceous fraction,whereas low combustion temperature generates higher molecular weight carbona-ceous fraction through polymerization and the predominance of condensation.There is organic fraction, within the engine, generally generated by two ways:direct ways, which is unburned and overmixed with air–fuel passes or escapes fromcombustion and indirect way, in which quenching of fuel by continuous mixinginterrupts the pyrolytic process (fuel to soot conversion). The formation of ashfraction in the engine arises from inorganic component in fuel or some inorganicadditives in fuel (adding for improving the efficiency of combustion). Lubricant canbe considered as the nonfuel source of particulate emission in vehicle’s combustion(Eastwood 2008; Brimblecombe et al. 2009).

After the combustion in an engine or reaching the exhaust valve, the engineexhaust has to take a lot of transformation toward particle formation. As mentionedin Fig. 2.1, there is affecting factors like dilution, cooling, wind speed, and ambient

2 Ultrafine Particles in Concern of Vehicular Exhaust … 11

humidity, which are governing the particle formation near tailpipe emission undernucleation mode, accumulation mode, and coarse mode (Eastwood 2008).

2.2.2 Regulations for Emission Control

With the advancement in technology and rapid urbanization, smoke became moreinimical as compared to the first fine civilization because of the use of fossil fuelinstead of wood as the principal fuel.

Fig. 2.1 Particle emission from vehicle engine

12 S. K. Yadav et al.

Back to the earlier period, the forests of England were compromised due toexpansion in the rate of population, which involved dire need of wood as a sourceof fuel and land for performing agriculture. When these issues were under scrutiny,it was written in the form of regulations into the legislative record. The first reg-ulation was issued by Edward I (reigned 1272–1307) which include a royalproclamation of forbidding coal burning in London. After that, Edward II (reigned1307–1327) came up with more stringent regulation of torturing the personsresponsible for fouling the air with coal smoke, whereas Richard II (reigned 1377–1399) adopted a humbler and an economic approach of controlling the use of coalby implementing taxation on coal burning. Later Henry V (reigned 1413–1422)established a commission which was used to regulate the entry of coal into London,and Elizabeth I (reigned 1558–1603) framed a new legislation against coalburning whenever there was a parliament sitting (Eastwood 2008; Brimblecombeet al. 2009).

By the time passed, in 1819, the problem reached at an alarming rate that acommittee was appointed by parliament to investigate the preventive measures tomake steam engines and furnaces less prejudicial to public health. As the industrialrevolution advanced, the chimney stacks were constructed at a prescribed height.

With tensions increasing among the member of Parliament, due to emissionsfrom locomotives and industries which finally led to the formation of the RailwayClauses Act of 1845, and also from factory furnaces by the Town ImprovementsClauses Act of 1847. Later in 1875, the law of English also regulated factory smokefrom the chimney under clauses in Public Health Acts. These laws and legislationwere flexible and depend on the amount and concentration of smoke which helpedin further laying down of the Smoke Abatement Act of 1926, which promoted thelocal authorities with power interested to enforce the provision of equipment in thenew building with the ultimate aim of prevention of smoke. Following these cri-teria, several towns established “smoke-free zones,” wherein all forms of smokegeneration were prohibited. The London smog scenario (December 4–9, 1992)brought a major change due to heavy casualties resulting in the introduction of theClean Air Act of 1959, making the emission of dark smoke an offense. But apartfrom so many changes and introductions in the laws, the mortality and morbidityrate in London for certain respiratory diseases remained same until the early 1960s.After this period of industrialization, the laws have finally done its part in con-trolling the smoke emission, thus resulting in the change of mass concentrationreduction from 300 to 60 g/m3 with some evidence of improvement in publichealth. The worldwide evolution of emission regulation has started since WorldWar II when the use of the automobile was augmented in government as well aspublic domain. With this, the first emission regulation (California AmbientResource Board) came in 1958, which was enforced in California state due tochanges in the ambient air quality because of rise in air pollution. With an aim toimprove vehicular pollution, the USA in 1960 rolled out an Environment ProtectionAgency (EPA) which aimed to shut down or improve the quality of old vehiclemodels. Following this pattern on emission control, Europe, Japan, and other Asiancountries formulated and introduced emission control techniques in their countries.

2 Ultrafine Particles in Concern of Vehicular Exhaust … 13

In the beginning, the laws and emission standards only covered gaseous pollutantslike unburnt total hydrocarbons, carbon monoxide (CO), and oxides of nitrogen(NOx). However, first time in 1985, California Ambient Resource Board (CARB)introduced a new regulation as particulate matter specially for diesel-run vehicles.Till July 1988, the emission regulation in Europe covered only gaseous pollutants,but from 1988 onward PM10 was introduced diesel vehicles. Similarly, in India, anew emission standard was introduced covering the whole country under CentralMotor Vehicle Rule (CMVR) NO. 15 for idling emissions, whereas for gaseouspollutant, mass emission standards were introduced from 1991 for gasoline high dutyvehicles and in 1992 for diesel vehicles. Generally, Indian emission regulations are inharmonization with European regulations. Emission road is directly associated withfuel roadmap. Currently, vehicles in Europe are practicing Euro VI norms with sulfurlevel of about 10 ppm, which introduced since 2014 and it covers PM2.5 and par-ticulate matter for both gasoline and diesel direct injection vehicles. In India cur-rently, all vehicles are running on Bharat Stage IV norms with over 50 ppm sulfurlevel, which has resulted in drastic reduction in diesel sulfur since 1996. As per thelatest information by the government, India is looking forward to introducing BharatStage-VI by 2020, thus skipping Bharat Stage-V which will result in ultralow sulfurbelow 100 ppm. Almost every pollutant is tightened nearly up to 90% from theirbaseline norms since they were introduced showing the stringency of the emissionnorms. With the latest reports on rising level of air pollution, the Light DieselVehicle (LDV) and passenger cars particle emission standards have to tighten untilEuro VI to the level of 98.2% from its baseline standards. By adopting advancedengines and exhaust techniques after desired treatment technologies, vehicle man-ufacturers can now meet these very high stringent norms. Even after the stringentrules and norms, 98% could not show much improvement and effectiveness inambient air quality. This can be proved from the increased rate of mortality due to airpollution, specifically ultrafine particles, which has resulted in various health-relatedissues like bronchitis, asthma and hardening of blood veins, cardiovascular diseases,and spread of cancers of different organs in both old and young generations. More onEuro and Bharat Stage (BS) standards is given at the end of this chapter (Eastwood2008; Williams 2004; Damanik et al. 2018).4

2.3 Ultrafine Particulates Matter (UFPs)

According to M. Harrison, UFPs got more scientific and regulatory attention afterprogress of the nanotechnology and nanoparticles measuring techniques (Harrisonet al. 1998). The terminology “Ultrafine Particles” in ambient air does not have auniversally accepted definition; however, particles less than 200 nm may be consid-ered UFP but definitions are usually based on Particle Number Count (PNC), where

4Commercial M Euro vi.

14 S. K. Yadav et al.