1、Alternative Fuels Emissions, Economics, and PerformanceALTERNATIVE FUELS: Emissions, Economics, and Performance Timothy T. Maxwell Jesse C. Jones Mechanical Engineering Department Texas Tech University Published by: Society of Automotive Engineers, Inc. 400 Commonwealth Drive Warrendale, PA 15096-00
2、01 U.S.A. Phone: (412) 776-4841 Fax: (412) 776-5760 Copyright 1995 Society of Automotive Engineers, Inc. eISBN: 978-0-7680-3608-4Library of Congress Cataloging-in-Publication Data Maxwell, T. T. Alternative fuels: emissions, economics, and performance / Timothy T. Maxwell, Jesse C. Jones p. cm. Incl
3、udes index. ISBN 1-56091-523-4: $59.00 1. Motor fuels. I. Jones, Jesse C. II. Title. TP343.M295 1994 94-23270 629.2538dc20 CIP Copyright 1995 Society of Automotive Engineers, Inc. ISBN 1-56091-523-4 All rights reserved. Printed in the United States of America. Permission to photocopy for internal or
4、 personal use, or the internal or personal use of specific clients, is granted by SAE for libraries and other users registered with the Copyright Clearance Center (CCC), provided the base fee of $.50 per page is paid directly to CCC, 222 Rosewood Dr., Danvers, MA 01923. Special requests should be ad
5、dressed to the SAE Publications Group. 1-56091-523-4/95 $.50. SAE Order No. R-143PREFACE This text was written as a reference for personnel responsible for purchasing, maintaining, and operating vehicles for state and local gov- ernment agencies, school districts, universities, and private companies
6、. Current information on alternative fuels technology, legislation, vehicle conversions, fuel properties, and refueling equipment is included. Alter- native fuels legislation considered to be representative of state law is included in the form of law enacted by the State of Texas. The federal Clean
7、Air Act Amendments of 1990 and the Comprehensive National Energy Policy Act of 1992 are also discussed in relation to their impact on the use of alternative fuels. A review of basic engine performance and terminology is also presented. This review provides the reader with the basic foundation of eng
8、ine technology necessary to fully understand the material presented in later chapters. An overview of cost benefit analysis relative to the alternative fuels conversion decision is included to assist the reader in determining the economic viability of adopting a particular fuel. Refueling facilities
9、 necessary for the various alternative fuels are described. Vehicle conversion hardware and procedures for both spark ignition and compression ignition engines are discussed and a list of vendors is provided. A glossary of terms relevant to alternative fuels is also included. This book can be used a
10、s a reference and as text for alternative fuels instruction. The information presented here was originally assembled for use in a series of seminars on alternative fuels and is intended to provideii Alternative Fuels: Emissions, Economics and Performance an understanding of the fundamentals of alter
11、native fuels and related topics. The material included is appropriate for use as a textbook for workshops and specialized training courses for a wide variety of person- nel associated with vehicle selection, operation, maintenance, and testing. This material will provide fleet managers who are consi
12、dering adding alternatively fueled vehicles to their fleets with an understanding of the essentials necessary for making informed decisions. Lubbock, Texas December 1993 Timothy T. Maxwell Jesse C. JonesACKNOWLEDGEMENTS The authors are indebted to many individuals, agencies, and companies for provid
13、ing technical information, encouragement, and advice during the preparation of this book. Personnel from the Texas Railroad Com- mission, General Services Commission, Air Control Board, and South- west Research Institute in San Antonio assisted the authors in presenting a workshop on alternative fue
14、ls during the fall of 1992 which provided the incentive for preparation of a comprehensive text on alternative fuels. These workshops were funded, in part, by the State of Texas Governors Energy Office, largely through the efforts of James P. McIntyre, now retired. The Texas General Land Office, thr
15、ough their sponsorship of the Annual Alternative Fuels Market Fair and Symposium, provided a forum for contact with industry representatives involved in alternative fuels component and systems sales. These contacts were essential in collect- ing information on equipment available and in establishing
16、 the cost of various hardware items. We would be remiss if we did not mention the knowledge gained in par- ticipating in the 1989-90 SAE Methanol Marathon/Challenge and in the 1991-93 SAE Natural Gas Vehicle Challenge administered by the Soci- ety of Automotive Engineers and Argonne National Laborat
17、ories and sponsored by the U.S. Department of Energy, General Motors, and the Canadian Department of Energy, Mines, and Resources. In addition to the competition sponsors, Allied Signal, Air Products and Chemicals, Felpro, Mesa Environmental, and many other companies providediv Alternative Fuels: Em
18、issions, Economics, and Performance hardware, fuel, and advice to the Texas Tech teams. Much of the infor- mation on methanol and natural gas fueled vehicles included in the text came from the experience gained in preparing and testing these vehicles for the five competitions. Finally, we need to re
19、cognize the support received from individuals and firms in the local area. Energas, the natural gas supply company for Lubbock, Texas, provided funding and CNG refueling access, as well as loaned equipment, for Texas Tech Universitys natural gas programs. Scoggin-Dickey GM Parts provided specialty p
20、erformance parts and advice for both the methanol and natural gas programs. Dubose Automo- tive and Machine provided invaluable support for precision machining, engine assembly, and dynamometer testing. Martha Hise, from Texas Techs Division of Continuing Education, administered the three series of
21、workshops related to alternative fuels presented by the authors and generally added the levity needed to make that experience enjoyable. Mrs. Carmen Hernandez helped in so many ways by providing secre- tarial services, accessing reference material, scheduling and arranging trips, etc. Invaluable ass
22、istance was provided by many individuals that are not spe- cifically mentioned by name here. The list is so long that we didnt feel that it was appropriate to try to include it; besides, we worried about unintentionally leaving someone out that should be recognized. To say that this text could not h
23、ave been written without an enormous amount of help is an understatement. We want to thank every person, govern- ment agency, and company that has contributed in any way to this effort and add our hope that the product reflects the quality of the assistance.TABLE OF CONTENTS Chapter 1 Chapter 2 Chap
24、ter 3 Chapter 4 Chapter 5 Chapter 6 Chapter 7 Chapter 8 Glossary Appendices Appendix A Appendix B Appendix C Index Introduction Review of Engine Technology Characteristics of Alternative Fuels Conversion of Spark Ignition Engines Conversion of Compression Ignition Engines Refueling Facilities Legisl
25、ation and Policies Cost Considerations Design of a CNG Refueling Facility Vendors with CARB Approved Conversion Kits Equipment Suppliers 1 13 29 75 123 143 163 197 239 277 299 303 307CHAPTER 1 INTRODUCTION 1.1 Background The primary automotive fuels currently in use are gasoline and diesel. These fu
26、els have powered the vast majority of ground vehicles since the early part of the 20th century; however, a few countries like Italy, Brazil, and New Zealand have developed vehicle transportation systems based on other fuels, primarily as a result of economic considerations associ- ated with feedstoc
27、k availability. Development of the internal combus- tion engine has closely paralleled the availability of better quality gasolines and diesel fuels with more desirable combustion characteris- tics and less variability. Standards for gasoline and diesel have been established to ensure that these fue
28、ls meet minimum requirements and to allow vehicle manufacturers to design engines for specific fuel proper- ties (ASTM 439 Specification for Automotive Gasoline, Federal Specifi- cation VV-G-1690C, and SAE J312 OCT88 for gasoline, and ASTM D-975 and SAE J313 JUN89 for diesel). Important spark igniti
29、on (SI) engine fuel considerations include octane number (anti-knock character- istics); heating value; vapor pressure; density; and the blending of addi- tives including anti-oxidants, corrosion inhibitors, biocides, anti-static compounds, and demulsifiers. Diesel fuel characteristics of concern in
30、- clude cetane number (compression ignition effectiveness), heating value, sulfur content, viscosity, volatility, cloud point, and flash point.2 Chapter 1 In the 1920s it was discovered that the anti-knock characteristic of gaso- line could be greatly improved by adding lead alkyls, primarily tetra-
31、 ethyl lead (TEL). The addition of TEL to gasoline increases the octane and allows the compression ratio of a spark ignition engine to be increased (the addition of approximately three grams of TEL per gallon of gasoline provides an average gain of 10 in octane number 1). A higher compres- sion rati
32、o provides a more energy efficient engine and produces more power. The lead in gasoline also tends to form deposits on upper cylinder components, which protect valve seats, but pose a problem for spark plugs. Environmental problems associated with lead toxicity recognized during the 1960s were large
33、ly due to lead in vehicle exhaust emissions. This toxicity problem ultimately led to the elimination of TEL from gaso- line. In addition to the other problems associated with its use, lead poisons the catalyst systems used to reduce exhaust emissions. The move to unleaded fuels caused many changes i
34、n engine design. As an example, unleaded gasoline produced excessive exhaust valve wear in engines designed to burn leaded gasoline. The valve wear problems, which resulted from localized welding of the surface peaks of the valve to the valve seat, were subsequently solved by incorporating hardened
35、valve seats and stellite coatings for the valves. The move to harder valve seats later turned out to be of benefit to the use of alternative fuels which, like unleaded gasoline, contain no lead and thus do not provide a protective coating for the valve seat. Unleaded gasolines tend to have lower oct
36、ane ratings, 87 to 91, than do leaded gasolines. Thus, additives, oxygenated compounds such as alcohol, methyl tertiary butyl ether (MTBE), and ethyl tertiary butyl ether (ETBE), are mixed with gasoline to increase octane ratings. Since many of these additives are alcohol derivatives, they tend to h
37、ave the same problems (to a lesser degree) with degrada- tion of rubber and plastic components as do the leading alternative alcohol fuels, methanol and ethanol. With the advent of the oil embargo of the early 1970s and the subsequent lack of availability and increase in gasoline prices there appear
38、ed to be a clear mandate for greater energy independence in the U.S. Considerable research and incentives were supported by the Federal government at this time to encourage the use of energy alternatives and to conserve energy, thus reducing U.S. dependence on foreign oil. Unfortunately, much of the
39、 effort and commitment of the late 1970s and early 80s toward finding a long-term solution to the energy crisis had abated until eventsIntroduction 3 in the Middle-East during the summer of 1990 rekindled interest. If the U.S. wants to achieve energy independence, some alternative must be found to t
40、he present situation in which half of its crude oil (and automo- tive fuel) needs are satisfied by imports. The transportation fuel problem is not limited to just feedstock availabil- ity and security. The degradation of the environment affects every person on earth and, unless the quality of the ai
41、r is improved, future generations of Americans may be obliged to make significant changes in their lifestyle. The quality of the mantle of air that surrounds the earth has degraded to the extent that warnings are issued in many cities when contamination levels reach the danger zone. Joggers are warn
42、ed about jogging at times of the day when smog levels are high and many metropolitan areas in the world have enacted motor and other industrial emissions controls in an attempt to lower air pollution levels. Over 100 cities in the U.S. rou- tinely exceed acceptable ozone levels as a result of smog b
43、uildup. In Mexico City street vendors sell the opportunity to breathe 90 seconds of fresh air for $2.00. In the Los Angeles basin, which has the most strin- gent air pollution restrictions in the world, a major effort is underway to promote the use of alternative fuels in motor vehicles. In the beli
44、ef that alternative fuels may reduce air pollution, the South Coast Air Quality Management District, which regulates air pollution in the Los Angeles basin, in 1988 initiated a five-year, $30 million program to fund metha- nol and natural gas vehicle projects. The Clean Air Act Amendments of 1990 an
45、d the Comprehensive National Energy Policy Act of 1992 have further encouraged the automobile industry, fleet operators, and individual vehicle owners to consider alter- native fuels. New federal tailpipe emissions standards, scheduled to be phased in by the 1995 model year, are patterned after toug
46、h California standards. If the air quality in the non-attainment cities does not meet Federal clean air standards by the turn of the century, even more strin- gent requirements will be adopted, including the required use of alter- natively fueled vehicles in cities having unhealthy levels of carbon
47、monoxide. In California, the unquestioned leader in setting stringent emis- sion standards, increasingly tough standards have been adopted for application through the end of this century and into the 21st century. Beginning in 1998, 2% of the vehicles sold in California must have zero emissions. By
48、the year 2003, the zero emission requirement increases to 10% of the vehicles sold. Thirteen northeastern states have adopted4 Chapter 1 Californias Low Emission Vehicle (LEV) standards which become effective in 1995, and most of the other states have enacted vehicle emis- sion control legislation o
49、f one type or another. There is little doubt that significant changes are going to occur during the next ten years in the transportation segment of the U.S. economy, at least in the major metro- politan areas where air quality is marginal. Under the pressure of state and federal legislation, the big three U.S. automobile companies and 14 major oil companies have formed a con- sortium to sponsor a joint research program entitled the Auto/Oil Air Quality Improvement Program. The purpose of this program is to develop a combination of clean burning fuels and engine systems that will s
