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1、Hybrid and Alternative Fuel VehiclesBy James D Halderman and Tony Martin 2009 Pearson Education, Inc.Pearson Prentice HallUpper Saddle River, NJ 07458Hybrid and Alternative Fuel VehiclesBy James D Halderman and Tony Martin 2009 Pearson Education, Inc.Pearson Prentice HallUpper Saddle River, NJ 07458
2、OBJECTIVESAfter studying Chapter 4, the reader should be able to:1. Describe how the proper grade of gasoline affects engine performance.2. List gasoline purchasing hints.3. Discuss how volatility affects driveability.4. Explain how oxygenated fuels can reduce CO exhaust emissions.5. Discuss the adv
3、antages and disadvantages of various alternative fuels.Hybrid and Alternative Fuel VehiclesBy James D Halderman and Tony Martin 2009 Pearson Education, Inc.Pearson Prentice HallUpper Saddle River, NJ 07458AUTOMOTIVE FUEL REFININGPetroleum (meaning rock oil) crude can be as thin and light colored as
4、apple cider or as thick and black as melted tar. Thin crude oil has a high American Petroleum Institute (API) gravity and, therefore, is called high-gravity crude and thick crude oil is called low-gravity crude. High-gravity-type crude contains more natural gasoline and its lower sulfur and nitrogen
5、 contents make it easier to refine. Low-sulfur crude oil is also known as “sweet” crude and high-sulfur crude oil is also known as “sour.”Hybrid and Alternative Fuel VehiclesBy James D Halderman and Tony Martin 2009 Pearson Education, Inc.Pearson Prentice HallUpper Saddle River, NJ 07458Processes Re
6、fining is a complex combination of interdependent processing units, Called distillation.Hybrid and Alternative Fuel VehiclesBy James D Halderman and Tony Martin 2009 Pearson Education, Inc.Pearson Prentice HallUpper Saddle River, NJ 07458DistillationDistillation works because crude is composed of hy
7、drocarbons with a wide range of molecular weights and, therefore, a broad range of boiling points. Each product was assigned a temperature range and the product was obtained by condensing the vapor that boiled off in this range at atmospheric pressure (atmospheric distillation). The earliest crude s
8、tills were simple pot stills consisting of a container where crude was heated and a condenser to condense the vapor. Later, distillation became a continuous process with a pump to provide crude flow, a furnace to heat the crude, and a distillation column to separate the different boiling cuts. Hybri
9、d and Alternative Fuel VehiclesBy James D Halderman and Tony Martin 2009 Pearson Education, Inc.Pearson Prentice HallUpper Saddle River, NJ 07458Cracking The discovery that hydrocarbons with higher boiling points could be broken down (cracked) into lower-boiling hydrocarbons by subjecting them to ve
10、ry high temperatures offered a way to correct the mismatch between supply and demand. This process, thermal cracking, was used to increase gasoline production starting in 1913. It is the nature of thermal cracking to make a lot of olefins, which have higher octane numbers but may cause engine deposi
11、ts. Eventually heat was supplemented by a catalyst, transforming thermal cracking into catalytic cracking. A catalyst is a material that speeds up or otherwise facilitates a chemical reaction without undergoing a permanent chemical change itself. Catalytic cracking produces gasoline of higher qualit
12、y than thermal cracking. Hybrid and Alternative Fuel VehiclesBy James D Halderman and Tony Martin 2009 Pearson Education, Inc.Pearson Prentice HallUpper Saddle River, NJ 07458Hydrocracking is similar to catalytic cracking in that it uses a catalyst, but the catalyst is in a hydrogen atmosphere. Othe
13、r types of refining processes include:ReformingAlkylationIsomerizationHydrotreatingDesulfurizationHybrid and Alternative Fuel VehiclesBy James D Halderman and Tony Martin 2009 Pearson Education, Inc.Pearson Prentice HallUpper Saddle River, NJ 07458Hybrid and Alternative Fuel VehiclesBy James D Halde
14、rman and Tony Martin 2009 Pearson Education, Inc.Pearson Prentice HallUpper Saddle River, NJ 07458ShippingThe gasoline is transported to regional storage facilities by tank railway car or by pipeline. In the pipeline all gasoline from many refiners is often sent through the same pipeline and can bec
15、ome mixed. All gasoline is said to be miscible meaning that it is capable of being mixed because each grade is created to specification so there is no reason to keep the different gasoline brands separated except for grade. Regular grade, midgrade, and premium grades are separated in the pipeline an
16、d the additives are added at the regional storage facilities and then shipped by truck to individual gas stations. Hybrid and Alternative Fuel VehiclesBy James D Halderman and Tony Martin 2009 Pearson Education, Inc.Pearson Prentice HallUpper Saddle River, NJ 07458GASOLINEGasoline is a term used to
17、describe a complex mixture of various hydrocarbons refined from crude petroleum oil for use as a fuel in engines. Most gasoline is blended to meet the needs of the local climates and altitudes. Hybrid and Alternative Fuel VehiclesBy James D Halderman and Tony Martin 2009 Pearson Education, Inc.Pears
18、on Prentice HallUpper Saddle River, NJ 07458What Is a California Gas Can?When researching for ways to reduce hydrocarbon emissions in California, it was discovered that leakage from small gasoline containers used to refill small lawnmowers and other power equipment was a major source of unburned gas
19、oline entering the atmosphere. As a result of this discovery, a new design for a gas can (container) was developed that is kept closed by a spring and uses O-rings to seal the opening. Hybrid and Alternative Fuel VehiclesBy James D Halderman and Tony Martin 2009 Pearson Education, Inc.Pearson Prenti
20、ce HallUpper Saddle River, NJ 07458Hybrid and Alternative Fuel VehiclesBy James D Halderman and Tony Martin 2009 Pearson Education, Inc.Pearson Prentice HallUpper Saddle River, NJ 07458VOLATILITYVolatility describes how easily the gasoline evaporates (forms a vapor). The definition of volatility ass
21、umes that the vapors will remain in the fuel tank or fuel line and will cause a certain pressure based on the temperature of the fuel. Hybrid and Alternative Fuel VehiclesBy James D Halderman and Tony Martin 2009 Pearson Education, Inc.Pearson Prentice HallUpper Saddle River, NJ 07458Winter Blend Re
22、id vapor pressure (RVP) is the pressure of the vapor above the fuel when the fuel is at 100F (38C). Increased vapor pressure permits the engine to start in cold weather. Gasoline without air will not burn. Gasoline must be vaporized (mixed with air) to burn in an engine. Cold temperatures reduce the
23、 normal vaporization of gasoline; therefore, winter-blended gasoline is specially formulated to vaporize at lower temperatures for proper starting and driveability at low ambient temperatures. Hybrid and Alternative Fuel VehiclesBy James D Halderman and Tony Martin 2009 Pearson Education, Inc.Pearso
24、n Prentice HallUpper Saddle River, NJ 07458Summer Blend At warm ambient temperatures, gasoline vaporizes easily. The volatility of summer-grade gasoline should be about 7.0 psi RVP. According to ASTM standards, the maximum RVP should be 10.5 psi for summer-blend gasoline. Hybrid and Alternative Fuel
25、 VehiclesBy James D Halderman and Tony Martin 2009 Pearson Education, Inc.Pearson Prentice HallUpper Saddle River, NJ 07458Volatility ProblemsAt higher temperatures, liquid gasoline can easily vaporize, which can cause vapor lock. Vapor lock is a lean condition caused by vaporized fuel in the fuel s
26、ystem. This vaporized fuel takes up space normally occupied by liquid fuel. Vapor lock is caused by bubbles that form in the fuel, preventing proper operation of the fuel-injection system. Hybrid and Alternative Fuel VehiclesBy James D Halderman and Tony Martin 2009 Pearson Education, Inc.Pearson Pr
27、entice HallUpper Saddle River, NJ 07458If winter-blend gasoline (or high-RVP fuel) is used in an engine during warm weather, the following problems may occur:1. Rough idle2. Stalling 3. Hesitation on acceleration4. Surging Hybrid and Alternative Fuel VehiclesBy James D Halderman and Tony Martin 2009
28、 Pearson Education, Inc.Pearson Prentice HallUpper Saddle River, NJ 07458The RVP can be tested using the test kit.Hybrid and Alternative Fuel VehiclesBy James D Halderman and Tony Martin 2009 Pearson Education, Inc.Pearson Prentice HallUpper Saddle River, NJ 07458DISTILLATION CURVEBesides Reid vapor
29、 pressure, another method of classifying gasoline volatility is the distillation curve. A curve on a graph is created by plotting the temperature where the various percentage of the fuel evaporates. Hybrid and Alternative Fuel VehiclesBy James D Halderman and Tony Martin 2009 Pearson Education, Inc.
30、Pearson Prentice HallUpper Saddle River, NJ 07458DRIVEABILITY INDEXA distillation curve shows how much of a gasoline evaporates at what temperature range. To predict cold weather driveability, an index was created called the Driveability Index, also called Distillation Index, abbreviated DI.The DI w
31、as developed using the temperature for the evaporated percentage of 10 percent (labeled T10), 50 percent (labeled T50), and 90 percent (labeled T90). The formula for DI is:DI = 1.5 T10 + 3 T50 + T90The total DI is a temperature and usually ranges from 1000 to 1200F. The lower values of DI generally
32、result in good cold-start and warm-up performance. A high DI number is less volatile than a low DI number. Hybrid and Alternative Fuel VehiclesBy James D Halderman and Tony Martin 2009 Pearson Education, Inc.Pearson Prentice HallUpper Saddle River, NJ 07458NORMAL AND ABNORMAL COMBUSTIONThe octane ra
33、ting of gasoline is the measure of its antiknock properties. Engine knock (also called detonation, spark knock, or ping) is a metallic noise an engine makes, usually during acceleration, resulting from abnormal or uncontrolled combustion inside the cylinder. Hybrid and Alternative Fuel VehiclesBy Ja
34、mes D Halderman and Tony Martin 2009 Pearson Education, Inc.Pearson Prentice HallUpper Saddle River, NJ 07458Normal combustion occurs smoothly and progresses across the combustion chamber from the point of ignition. Hybrid and Alternative Fuel VehiclesBy James D Halderman and Tony Martin 2009 Pearso
35、n Education, Inc.Pearson Prentice HallUpper Saddle River, NJ 07458During periods of spark knock (detonation), the combustion speed increases by up to 10 times to near the speed of sound. The increased combustion speed also causes increased temperatures and pressures, which can damage pistons, gasket
36、s, and cylinder heads. Hybrid and Alternative Fuel VehiclesBy James D Halderman and Tony Martin 2009 Pearson Education, Inc.Pearson Prentice HallUpper Saddle River, NJ 07458OCTANE RATINGThe antiknock standard or basis of comparison was the knock-resistant hydrocarbon isooctane, chemically called tri
37、methylpentane (C8H18), also known as 224 trimethylpentane. If a gasoline tested had the exact same antiknock characteristics as isooctane, it was rated as 100-octane gasoline. If the gasoline tested had only 85% of the antiknock properties of isooctane, it was rated as 85 octane. Remember, octane ra
38、ting is only a comparison test. The two basic methods used to rate gasoline for antiknock properties (octane rating) are the research method and the motor method. Each uses a model of the special cooperative fuel research (CFR) single-cylinder engine. The research method and the motor method vary as
39、 to temperature of air, spark advance, and other parameters. The research method typically results in readings that are six to ten points higher than those of the motor method. For example, a fuel with a research octane number (RON) of 93 might have a motor octane number (MON) of 85. Hybrid and Alte
40、rnative Fuel VehiclesBy James D Halderman and Tony Martin 2009 Pearson Education, Inc.Pearson Prentice HallUpper Saddle River, NJ 07458The octane rating posted on pumps in the United States is the average of the two methods and is referred to as (R + M) 2, meaning that, for the fuel used in the prev
41、ious example, the rating posted on the pumps would beRON + MON = 93 + 85 = 89 2 2 The pump octane is called the antiknock index (AKI). Hybrid and Alternative Fuel VehiclesBy James D Halderman and Tony Martin 2009 Pearson Education, Inc.Pearson Prentice HallUpper Saddle River, NJ 07458GASOLINE GRADES
42、 AND OCTANE NUMBERThe posted octane rating on gasoline pumps is the rating achieved by the average of the research and the motor methods. Hybrid and Alternative Fuel VehiclesBy James D Halderman and Tony Martin 2009 Pearson Education, Inc.Pearson Prentice HallUpper Saddle River, NJ 07458Except in hi
43、gh-altitude areas, the grades and octane ratings are as follows:GradesOctane ratingRegular87Midgrade (also called Plus)89Premium91 or higherHybrid and Alternative Fuel VehiclesBy James D Halderman and Tony Martin 2009 Pearson Education, Inc.Pearson Prentice HallUpper Saddle River, NJ 07458OCTANE IMP
44、ROVERSOctane improvers (enhancers) can be grouped into three broad categories:1. Aromatic hydrocarbons (hydrocarbons containing the benzene ring) such as xylene and toluene2. Alcohols such as ethanol (ethyl alcohol), methanol (methyl alcohol), and tertiary butyl alcohol (TBA)3. Metallic compounds su
45、ch as methylcyclopentadienyl manganese tricarbonyl (MMT)Propane and butane, which are volatile byproducts of the refinery process, are also often added to gasoline as octane improvers. The increase in volatility caused by the added propane and butane often leads to hot-weather driveability problems.
46、Hybrid and Alternative Fuel VehiclesBy James D Halderman and Tony Martin 2009 Pearson Education, Inc.Pearson Prentice HallUpper Saddle River, NJ 07458OXYGENATED FUELSOxygenated fuels contain oxygen in the molecule of the fuel itself. Examples of oxygenated fuels include methanol, ethanol, methyl ter
47、tiary butyl ether (MTBE), tertiary-amyl methyl ether (TAME), and ethyl tertiary butyl ether (ETBE).The extra oxygen in the fuel helps ensure that there is enough oxygen to convert all the CO into CO2 during the combustion process in the engine or catalytic converter.Hybrid and Alternative Fuel Vehic
48、lesBy James D Halderman and Tony Martin 2009 Pearson Education, Inc.Pearson Prentice HallUpper Saddle River, NJ 07458Methyl Tertiary Butyl Ether (MTBE) MTBE is manufactured by means of the chemical reaction of methanol and isobutylene. Unlike methanol, MTBE does not increase the volatility of the fu
49、el, and is not as sensitive to water as are other alcohols. The maximum allowable volume level, according to the EPA, is 15% but is currently being phased out due to concern with health concerns, as well as MTBE contamination of drinking water if spilled from storage tanks. Hybrid and Alternative Fu
50、el VehiclesBy James D Halderman and Tony Martin 2009 Pearson Education, Inc.Pearson Prentice HallUpper Saddle River, NJ 07458Tertiary-Amyl Methyl Ether Tertiary-amyl methyl ether (TAME) is an oxygenate added to gasoline and is flammable and can form explosive mixtures with air. It is slightly solubl
51、e in water, very soluble in ethers and alcohol, and in most organic solvents including hydrocarbons. TAME is an ether, which contains an oxygen atom bonded to two carbon atoms. Hybrid and Alternative Fuel VehiclesBy James D Halderman and Tony Martin 2009 Pearson Education, Inc.Pearson Prentice HallU
52、pper Saddle River, NJ 07458Ethyl Tertiary Butyl Ether ETBE is derived from ethanol. The maximum allowable volume level is 17.2%. The use of ETBE is the cause of much of the odor from the exhaust of vehicles using reformulated gasoline. Hybrid and Alternative Fuel VehiclesBy James D Halderman and Ton
53、y Martin 2009 Pearson Education, Inc.Pearson Prentice HallUpper Saddle River, NJ 07458Ethanol Ethyl alcohol is drinkable alcohol and is usually made from grain. Adding 10% ethanol (ethyl alcohol or grain alcohol) increases the (R + M) 2 octane rating by three points. The alcohol added to the base ga
54、soline, however, also raises the volatility of the fuel about 0.5 psi. Most automobile manufacturers permit up to 10% ethanol if driveability problems are not experienced. The oxygen content of a 10% blend of ethanol in gasoline, called E-10 is 3.5% oxygen by weight. Hybrid and Alternative Fuel Vehi
55、clesBy James D Halderman and Tony Martin 2009 Pearson Education, Inc.Pearson Prentice HallUpper Saddle River, NJ 07458Hybrid and Alternative Fuel VehiclesBy James D Halderman and Tony Martin 2009 Pearson Education, Inc.Pearson Prentice HallUpper Saddle River, NJ 07458Methanol Methyl alcohol is made
56、from wood (wood alcohol), natural gas, or coal. Methanol is poisonous if ingested and tends to be more harmful to the materials in the fuel system and to separate when combined with gasoline unless used with a co-solvent. A co-solvent is another substance (usually another alcohol) that is soluble in
57、 both methanol and gasoline and is used to reduce the tendency of the liquids to separate.Methanol can damage fuel system parts. Methanol is corrosive to lead (used as a coating of fuel tanks), aluminum, magnesium, and some plastics and rubber. Methanol can also cause rubber products (elastomers) to
58、 swell and soften. Methanol itself is 50% oxygen. Gasoline containing 5% methanol would have an oxygen content of 2.5% by weight. Hybrid and Alternative Fuel VehiclesBy James D Halderman and Tony Martin 2009 Pearson Education, Inc.Pearson Prentice HallUpper Saddle River, NJ 07458All alcohols absorb
59、water, and the alcohol-water mixture can separate from the gasoline and sink to the bottom of the fuel tank. This process is called phase separation. To help avoid engine performance problems, try to keep at least a quarter tank of fuel at all times, especially during seasons when there is a wide te
60、mperature span between daytime highs and nighttime lows.Hybrid and Alternative Fuel VehiclesBy James D Halderman and Tony Martin 2009 Pearson Education, Inc.Pearson Prentice HallUpper Saddle River, NJ 07458Hybrid and Alternative Fuel VehiclesBy James D Halderman and Tony Martin 2009 Pearson Educatio
61、n, Inc.Pearson Prentice HallUpper Saddle River, NJ 07458ALCOHOL ADDITIVES ADVANTAGES AND DISADVANTAGESThe advantages and disadvantages of using alcohol as an additive to gasoline can be summarized as follows: Hybrid and Alternative Fuel VehiclesBy James D Halderman and Tony Martin 2009 Pearson Educa
62、tion, Inc.Pearson Prentice HallUpper Saddle River, NJ 07458Advantages1. Alcohol absorbs moisture in the fuel tank.2. Ten percent alcohol added to gasoline raises the octane rating, (R + M) 2, by three points.3. Alcohol cleans the fuel system.4. Alcohol reduces CO emissions because it contains oxygen
63、. Hybrid and Alternative Fuel VehiclesBy James D Halderman and Tony Martin 2009 Pearson Education, Inc.Pearson Prentice HallUpper Saddle River, NJ 07458Disadvantages1. The use of alcohol can result in the clogging of fuel filters with dirt and other debris cleaned from the fuel tank, pump, and lines
64、.2. Alcohol raises the volatility of fuel about 0.5 psi; this can cause hot-weather driveability problems.3. Alcohol reduces the heat content of the resulting fuel mixture (it has about one-half of the energy content of gasoline); 60,000 to 75,000 British thermal units (BTUs) per gallon for alcohol
65、versus about 130,000 BTUs per gallon for gasoline.4. Alcohol absorbs water and then separates from the gasoline, especially as temperature drops. Separated alcohol and water on the bottom of the tank can cause hard starting during cold weather. Alcohol does not vaporize easily at low temperatures. H
66、ybrid and Alternative Fuel VehiclesBy James D Halderman and Tony Martin 2009 Pearson Education, Inc.Pearson Prentice HallUpper Saddle River, NJ 07458TESTING GASOLINE FOR ALCOHOL CONTENTTake the following steps when testing gasoline for alcohol content.1. Pour suspect gasoline into a small clean beak
67、er or glass container. DO NOT SMOKE OR RUN THE TEST AROUND SOURCES OF IGNITION!2. Carefully fill the graduated cylinder to the 10-mL mark.3. Add 2 mL of water to the graduated cylinder by counting the number of drops from an eyedropper. (Before performing the test, the eyedropper must be calibrated
68、to determine how many drops equal 2.0 mL.)4. Put the stopper in the cylinder and shake vigorously for 1 minute. Relieve built-up pressure by occasionally removing the stopper. Alcohol dissolves in water and will drop to the bottom of the cylinder.5. Place the cylinder on a flat surface and let it st
69、and for 2 minutes.6. Take a reading near the bottom of the cylinder at the boundary between the two liquids.7. For percent of alcohol in gasoline, subtract 2 from the reading and multiply by 10. Hybrid and Alternative Fuel VehiclesBy James D Halderman and Tony Martin 2009 Pearson Education, Inc.Pear
70、son Prentice HallUpper Saddle River, NJ 07458For example,The reading is 3.1 mL: 3.1 - 2 = 1.1 X 10 = 11% alcoholThe reading is 2.0 mL: 2 - 2 = 0 X 10 = 0% alcohol (no alcohol)If the increase in volume is 0.2% or less, it may be assumed that the test gasoline contains no alcohol. Alcohol content can
71、also be checked using an electronic tester.Hybrid and Alternative Fuel VehiclesBy James D Halderman and Tony Martin 2009 Pearson Education, Inc.Pearson Prentice HallUpper Saddle River, NJ 07458AIR-FUEL RATIOSFuel burns best when the intake system turns it into a fine spray and mixes it with air befo
72、re sending it into the cylinders. In fuel-injected engines, the fuel becomes a spray and mixes with the air in the intake manifold. There is a direct relationship between engine airflow and fuel requirements; this is called the air-fuel ratio.Hybrid and Alternative Fuel VehiclesBy James D Halderman
73、and Tony Martin 2009 Pearson Education, Inc.Pearson Prentice HallUpper Saddle River, NJ 07458The air-fuel ratio is the proportion by weight of air and gasoline that the injection system mixes as needed for engine combustion. The mixtures, with which an engine can operate without stalling, range from
74、 8 to 1 to 18.5 to 1.Hybrid and Alternative Fuel VehiclesBy James D Halderman and Tony Martin 2009 Pearson Education, Inc.Pearson Prentice HallUpper Saddle River, NJ 07458These ratios are usually stated by weight, such as:8 parts of air by weight combined with 1 part of gasoline by weight (8:1), whi
75、ch is the richest mixture that an engine can tolerate and still fire reliably.18.5 parts of air mixed with 1 part of gasoline (18.5:1), which is the leanest practical ratio. Richer or leaner air-fuel ratios cause the engine to misfire badly or not run at all.Hybrid and Alternative Fuel VehiclesBy Ja
76、mes D Halderman and Tony Martin 2009 Pearson Education, Inc.Pearson Prentice HallUpper Saddle River, NJ 07458Stoichiometric Air-Fuel RatioThe ideal mixture or ratio at which all of the fuel combines with all of the oxygen in the air and burns completely is called the stoichiometric ratio, a chemical
77、ly perfect combination. In theory, this ratio is an air-fuel mixture of 14.7 to 1. Hybrid and Alternative Fuel VehiclesBy James D Halderman and Tony Martin 2009 Pearson Education, Inc.Pearson Prentice HallUpper Saddle River, NJ 07458The stoichiometric ratio is a compromise between maximum power and
78、maximum economy. Hybrid and Alternative Fuel VehiclesBy James D Halderman and Tony Martin 2009 Pearson Education, Inc.Pearson Prentice HallUpper Saddle River, NJ 07458Stoichiometric Air-Fuel Ratio for Various Fuels FuelHeat energy(BTU/gal)StoichiometricratioGasolineAbout 130,00014.7:1Ethyl (ethanol)
79、 alcoholAbout 76,0009.0:1Methyl (methanol) alcoholAbout 60,0006.4:1Hybrid and Alternative Fuel VehiclesBy James D Halderman and Tony Martin 2009 Pearson Education, Inc.Pearson Prentice HallUpper Saddle River, NJ 07458HIGH-ALTITUDE OCTANE REQUIREMENTSAs the altitude increases, atmospheric pressure dr
80、ops. The air is less dense because a pound of air takes more volume. The octane rating of fuel does not need to be as high because the engine cannot intake as much air. This process will reduce the combustion (compression) pressures inside the engine. In mountainous areas, gasoline (R + M) 2 octane
81、ratings are two or more numbers lower than normal (according to SAE, about one octane number lower per 1000 ft or 300 m in altitude).Hybrid and Alternative Fuel VehiclesBy James D Halderman and Tony Martin 2009 Pearson Education, Inc.Pearson Prentice HallUpper Saddle River, NJ 07458Hybrid and Altern
82、ative Fuel VehiclesBy James D Halderman and Tony Martin 2009 Pearson Education, Inc.Pearson Prentice HallUpper Saddle River, NJ 07458REFORMULATED GASOLINEReformulated gasoline (RFG) is manufactured by refiners to help reduce emissions. The gasoline refiners reformulate gasoline by using additives th
83、at contain at least 2% oxygen by weight and reducing the additive benzenes to a maximum of 1% by value. Two other major changes done at the refineries are as follows:1. Reduce light compounds. Refineries eliminate butane, pentane, and propane, which have a low boiling point and evaporate easily.2. R
84、educe heavy compounds. Refineries eliminate heavy compounds with high boiling points such as aromatics and olefins. The purpose of this reduction is to reduce the amount of unburned hydrocarbons that enter the catalytic converter, which makes the converter more efficient, thereby reducing emissions.
85、Hybrid and Alternative Fuel VehiclesBy James D Halderman and Tony Martin 2009 Pearson Education, Inc.Pearson Prentice HallUpper Saddle River, NJ 07458What Is “Top Tier” Gasoline”Top tier gasoline is gasoline that has specific standards for quality, including enough detergent to keep all intake valve
86、s clean. The standards developed by the four automobile manufacturers, including BMW, General Motors, Honda, and Toyota. Top tier gasoline exceeds the quality standards developed by the World Wide Fuel Charter (WWFC) that was established in 2002 by vehicle and engine manufacturers. The gasoline comp
87、anies that agreed to make fuel that matches or exceeds the standards as a top tier fuel include Chevron Texaco and Conoco Phillips. Ford has specified that BP fuel, sold in the eastern and Midwestern states, is the recommended fuel to use in Ford vehicles. Hybrid and Alternative Fuel VehiclesBy Jame
88、s D Halderman and Tony Martin 2009 Pearson Education, Inc.Pearson Prentice HallUpper Saddle River, NJ 07458Hybrid and Alternative Fuel VehiclesBy James D Halderman and Tony Martin 2009 Pearson Education, Inc.Pearson Prentice HallUpper Saddle River, NJ 07458To help ensure proper engine operation and
89、keep fuel costs to a minimum, follow these guidelines:1. Purchase fuel from a busy station to help ensure that it is fresh and less likely to be contaminated with water or moisture.2. Keep the fuel tank above one-quarter full, especially during seasons in which the temperature rises and falls by mor
90、e than 20F between daytime highs and nighttime lows. This helps to reduce condensed moisture in the fuel tank and could prevent gas line freeze-up in cold weather.3. Do not purchase fuel with a higher octane rating than is necessary. Try using premium high-octane fuel to check for operating differen
91、ces. Most newer engines are equipped with a detonation (knock) sensor that signals the vehicle computer to retard the ignition timing when spark knock occurs. Hybrid and Alternative Fuel VehiclesBy James D Halderman and Tony Martin 2009 Pearson Education, Inc.Pearson Prentice HallUpper Saddle River,
92、 NJ 074584. Avoid using gasoline with alcohol in warm weather, even though many alcohol blends do not affect engine driveability. If warm-engine stumble, stalling, or rough idle occurs, change brands of gasoline.5. Do not purchase fuel from a retail outlet when a tanker truck is filling the undergro
93、und tanks. During the refilling procedure, dirt, rust, and water may be stirred up in the underground tanks. This undesirable material may be pumped into your vehicles fuel tank.6. Do not overfill the gas tank. After the nozzle clicks off, add just enough fuel to round up to the next dime. Adding ad
94、ditional gasoline will cause the excess to be drawn into the charcoal canister. This can lead to engine flooding and excessive exhaust emissions.7. Be careful when filling gasoline containers. Always fill a gas can on the ground to help prevent the possibility of static electricity buildup during th
95、e refueling process. Hybrid and Alternative Fuel VehiclesBy James D Halderman and Tony Martin 2009 Pearson Education, Inc.Pearson Prentice HallUpper Saddle River, NJ 07458Hybrid and Alternative Fuel VehiclesBy James D Halderman and Tony Martin 2009 Pearson Education, Inc.Pearson Prentice HallUpper S
96、addle River, NJ 07458ALTERNATIVE FUELSAlternative fuels include a number of fuels besides gasoline for use in passenger vehicles. Hybrid and Alternative Fuel VehiclesBy James D Halderman and Tony Martin 2009 Pearson Education, Inc.Pearson Prentice HallUpper Saddle River, NJ 07458EthanolEthanol, also
97、 called ethyl alcohol or grain alcohol, because it is usually made from grain and is the type of alcohol found in alcoholic drinks such as beer, wine, and distilled spirits like whiskey. Ethanol is composed of two carbon atoms and six hydrogen atoms with one added oxygen atom. Hybrid and Alternative
98、 Fuel VehiclesBy James D Halderman and Tony Martin 2009 Pearson Education, Inc.Pearson Prentice HallUpper Saddle River, NJ 07458Conventional ethanol and cellulose ethanol is the same product, but are produced using non-food portion of the feedstock. Conventional ethanol is derived from grains, such
99、as corn, wheat, or soybeans.Cellulose ethanol can be produced from a wide variety of cellulose biomass feedstock, including agricultural plant wastes (corn stalks, cereal straws), plant wastes from industrial processes (sawdust, paper pulp) and energy crops grown specifically for fuel production. Th
100、ese non-grain products are often referred to as bio-mass.Hybrid and Alternative Fuel VehiclesBy James D Halderman and Tony Martin 2009 Pearson Education, Inc.Pearson Prentice HallUpper Saddle River, NJ 07458Two processing options are employed to produce fermentable sugars from cellulose biomass: Usi
101、ng acid hydrolysis to break down the complex carbohydrates into simple sugars. Enzymes are employed to convert the cellulose biomass to fermentable sugars. The final step involves microbial fermentation yielding ethanol and carbon dioxide. Hybrid and Alternative Fuel VehiclesBy James D Halderman and
102、 Tony Martin 2009 Pearson Education, Inc.Pearson Prentice HallUpper Saddle River, NJ 07458The majority of the ethanol in the United States is made from:CornGrainSorghumWheatBarleyPotatoesIn Brazil, the worlds largest ethanol producer, it is made from sugarcane. Hybrid and Alternative Fuel VehiclesBy
103、 James D Halderman and Tony Martin 2009 Pearson Education, Inc.Pearson Prentice HallUpper Saddle River, NJ 07458The major steps in the dry mill process include:1. Milling. The feedstock passes through a hammer mill which turns it into a fine powder called meal.2. Liquefaction. The meal is mixed with
104、 water and then passed through cookers where the starch is liquefied.3. Saccharification. The mash from the cookers is cooled and the secondary enzyme is added to convert the liquefied starch to fermentable sugars (dextrose).4. Fermentation. Yeast is added to the mash to ferment the sugars to ethano
105、l and carbon dioxide. 5. Distillation. The alcohol leaves the top of the final column at about 96% strength, and the residue mash, called silage, is transferred from the base of the column to the co-product processing area.6. Dehydration. The alcohol product at this stage is called anhydrous ethanol
106、 (pure, without water). 7. Denaturing. Ethanol that will be used for fuel must be denatured, or made unfit for human consumption, with a small amount of gasoline (2-5%), methanol, or denatonium benzoate. This is done at the ethanol plant.Hybrid and Alternative Fuel VehiclesBy James D Halderman and T
107、ony Martin 2009 Pearson Education, Inc.Pearson Prentice HallUpper Saddle River, NJ 07458E-85Vehicle manufacturers have available vehicles that are capable of operating on gasoline plus ethanol or a combination of gasoline and ethanol called E-85. E-85 is composed of 85% ethanol and 15% gasoline. Pur
108、e ethanol has an octane rating of about 113, whereas E-85, which contains 35% oxygen by weight, has an octane rating of about 100 to 105 compared to regular unleaded gasoline rating of 87. Hybrid and Alternative Fuel VehiclesBy James D Halderman and Tony Martin 2009 Pearson Education, Inc.Pearson Pr
109、entice HallUpper Saddle River, NJ 07458E-85 has less heat energy than gasoline.Gasoline = 114,000 BTUs per gallonE-85 = 87,000 BTUs per gallonThis means that the fuel economy is reduced by 20% to 30% if E-85 is used instead of gasoline. Hybrid and Alternative Fuel VehiclesBy James D Halderman and To
110、ny Martin 2009 Pearson Education, Inc.Pearson Prentice HallUpper Saddle River, NJ 07458The 15% gasoline in this blend helps the engine start, especially in cold weather. Vehicles equipped with this capability are commonly referred to as alternative fuel vehicle (AFV), Flex Fuel, flexible fuel vehicl
111、es, or FFV.Hybrid and Alternative Fuel VehiclesBy James D Halderman and Tony Martin 2009 Pearson Education, Inc.Pearson Prentice HallUpper Saddle River, NJ 07458E-85 vehicles use fuel system parts designed to withstand the additional alcohol content, modified driveability programs that adjust fuel d
112、elivery and timing to compensate for the various percentages of ethanol fuel, and a fuel compensation sensor that measures both the percentage of ethanol blend and the temperature of the fuel. This sensor is also called a variable fuel sensor. Hybrid and Alternative Fuel VehiclesBy James D Halderman
113、 and Tony Martin 2009 Pearson Education, Inc.Pearson Prentice HallUpper Saddle River, NJ 07458Hybrid and Alternative Fuel VehiclesBy James D Halderman and Tony Martin 2009 Pearson Education, Inc.Pearson Prentice HallUpper Saddle River, NJ 07458Hybrid and Alternative Fuel VehiclesBy James D Halderman
114、 and Tony Martin 2009 Pearson Education, Inc.Pearson Prentice HallUpper Saddle River, NJ 07458The benefits of E-85 vehicles are less pollution, less CO2 production, and less dependence on oil. Hybrid and Alternative Fuel VehiclesBy James D Halderman and Tony Martin 2009 Pearson Education, Inc.Pearso
115、n Prentice HallUpper Saddle River, NJ 07458MethanolMethanol, also known as methyl alcohol or wood alcohol, is a chemical compound with chemical formula that includes one carbon atom and four hydrogen atoms and one oxygen. Hybrid and Alternative Fuel VehiclesBy James D Halderman and Tony Martin 2009
116、Pearson Education, Inc.Pearson Prentice HallUpper Saddle River, NJ 07458Methanol is a light, volatile, colorless, tasteless, flammable, poisonous liquid with a very faint odor. It is used as an antifreeze, solvent, and fuel, and to denature ethanol. Methanol burns in air forming CO2 (carbon dioxide)
117、 and H2O (water). A methanol flame is almost colorless. Because of its poisonous properties, methanol is also used to denature ethanol. Methanol is often called wood alcohol because it was once produced chiefly as a byproduct of the destructive distillation of wood. Hybrid and Alternative Fuel Vehic
118、lesBy James D Halderman and Tony Martin 2009 Pearson Education, Inc.Pearson Prentice HallUpper Saddle River, NJ 07458Hybrid and Alternative Fuel VehiclesBy James D Halderman and Tony Martin 2009 Pearson Education, Inc.Pearson Prentice HallUpper Saddle River, NJ 07458The biggest source of methanol in
119、 the United States is coal. Using a simple reaction between coal and steam, a gas mixture called syn-gas (synthesis gas) is formed. The components of this mixture are carbon monoxide and hydrogen, which through an additional chemical reaction, are converted to methanol. Hybrid and Alternative Fuel V
120、ehiclesBy James D Halderman and Tony Martin 2009 Pearson Education, Inc.Pearson Prentice HallUpper Saddle River, NJ 07458Methanol is toxic and can cause blindness and death. It can enter the body by ingestion, inhalation, or absorption through the skin. Dangerous doses will build up if a person is r
121、egularly exposed to fumes or handles liquid without skin protection. If methanol has been ingested, a doctor should be contacted immediately. The usual fatal dose is 4 fl oz (100-125 mL). Hybrid and Alternative Fuel VehiclesBy James D Halderman and Tony Martin 2009 Pearson Education, Inc.Pearson Pre
122、ntice HallUpper Saddle River, NJ 07458M-85Some flexible fuel vehicles are designed to operate on 85% methanol and 15% gasoline. Methanol is very corrosive and requires that the fuel system components be constructed of stainless steel and other alcohol-resistant rubber and plastic components. The hea
123、t content of M-85 is about 60% of that of gasoline. Hybrid and Alternative Fuel VehiclesBy James D Halderman and Tony Martin 2009 Pearson Education, Inc.Pearson Prentice HallUpper Saddle River, NJ 07458PropanePropane is normally a gas but is easily compressed into a liquid and stored in inexpensive
124、containers. When sold as a fuel, it is also known as liquefied petroleum gas (LPG) or LP-gas because the propane is often mixed with about 10% of other gases such as butane, propylene, butylenes and mercaptan, to give the colorless and odorless propane a smell. Propane is nontoxic, but if inhaled, c
125、an cause asphyxiation through lack of oxygen. Propane is heavier than air and lays near the floor if released into the atmosphere. Propane is commonly used in forklifts and other equipment used inside warehouses and factories because the exhaust from the engine using propane is not harmful. Propane
126、comes from a byproduct of petroleum refining of natural gas. In order to liquefy the fuel, it is stored in strong tanks at about 300 psi (2000 kPa). The heating value of propane is less than that of gasoline; therefore, more is required, which reduces the miles per gallon economy. Hybrid and Alterna
127、tive Fuel VehiclesBy James D Halderman and Tony Martin 2009 Pearson Education, Inc.Pearson Prentice HallUpper Saddle River, NJ 07458Hybrid and Alternative Fuel VehiclesBy James D Halderman and Tony Martin 2009 Pearson Education, Inc.Pearson Prentice HallUpper Saddle River, NJ 07458Compressed Natural
128、 Gas (CNG)Another alternative fuel that is often used in fleet vehicles is compressed natural gas or CNG and is often referred to as a natural gas vehicle (NGV). Look for the blue CNG label on vehicles designed to operate on compressed natural gas. Hybrid and Alternative Fuel VehiclesBy James D Hald
129、erman and Tony Martin 2009 Pearson Education, Inc.Pearson Prentice HallUpper Saddle River, NJ 07458Natural gas has to be compressed to about 3000 psi (20,000 kPa) or more so that the weight and the cost of the storage container is a major factor when it comes to preparing a vehicle to run on CNG. Th
130、e tanks needed for CNG are typically constructed of 0.5 inch (3 mm) thick aluminum reinforced with fiberglass. The octane rating of CNG is about 130 and the cost per gallon is about half of the cost of gasoline. However, the heat value of CNG is also less and therefore, more is required to produce t
131、he same power and the miles per gallon is less. Hybrid and Alternative Fuel VehiclesBy James D Halderman and Tony Martin 2009 Pearson Education, Inc.Pearson Prentice HallUpper Saddle River, NJ 07458Compressed natural gas is made up of a blend of methane, propane, ethane, N-butane, carbon dioxide, an
132、d nitrogen. Once it is processed, it is at least 93% methane. Natural gas is nontoxic, odorless, and colorless in its natural state. It is odorized during processing, using ethyl mercaptan (“skunk”), to allow for easy leak detection. Natural gas is lighter than air and will rise when released into t
133、he air. Since CNG is already a vapor, it does not need heat to vaporize before it will burn, which improves cold start-up and results in lower emissions during cold operation. Hybrid and Alternative Fuel VehiclesBy James D Halderman and Tony Martin 2009 Pearson Education, Inc.Pearson Prentice HallUp
134、per Saddle River, NJ 07458Natural gas has an octane rating of about 115 octane. The stoichiometric ratio, the point at which all the air and fuel is used or burned is 16.5:1 compared to 14.7:1 for gasoline. This means that more air is required to burn one pound of natural gas than is required to bur
135、n one pound of gasoline.Engine changes needed to optimize the use of CNG as a fuel include the following: Hybrid and Alternative Fuel VehiclesBy James D Halderman and Tony Martin 2009 Pearson Education, Inc.Pearson Prentice HallUpper Saddle River, NJ 07458The CNG engine is designed to include:Increa
136、sed compression ratioStrong pistons and connecting rodsHeat resistant valvesFuel injectors designed for gaseous fuel instead of liquid fuel Hybrid and Alternative Fuel VehiclesBy James D Halderman and Tony Martin 2009 Pearson Education, Inc.Pearson Prentice HallUpper Saddle River, NJ 07458When compl
137、etely filled, the CNG tank has 3600 psi of pressure in the tank. When the ignition is turned on, the alternate fuel electronic control unit activates the high-pressure lock-off, which allows high-pressure gas to pass to the high-pressure regulator. The high-pressure regulator reduces the high-pressu
138、re CNG to approximately 170 psi and sends it to the low- pressure lock-off. The low-pressure lock-off is also controlled by the alternate fuel electronic control unit and is activated at the same time that the high-pressure lock-off is activated. From the low-pressure lock-off, the CNG is directed t
139、o the low-pressure regulator. This is a two-stage regulator that first reduces the pressure to approximately 4 to 6 psi in the first stage and then to 4.5 to 7 inches of water in the second stage. From here, the low-pressure gas is delivered to the gas mass sensor/mixture control valve. This valve c
140、ontrols the air-fuel mixture. The CNG gas distributor adapter then delivers the gas to the intake stream. Hybrid and Alternative Fuel VehiclesBy James D Halderman and Tony Martin 2009 Pearson Education, Inc.Pearson Prentice HallUpper Saddle River, NJ 07458There are three commonly used CNG refilling
141、station pressures which include:P24-2400 PSIP30-3000 PSIP36-3600 PSIHybrid and Alternative Fuel VehiclesBy James D Halderman and Tony Martin 2009 Pearson Education, Inc.Pearson Prentice HallUpper Saddle River, NJ 07458Try to find and use a station with the highest pressure to help ensure a long rang
142、e. Filling at lower pressures will result in less compressed natural gas being installed in the storage tank thereby reducing the driving range. Hybrid and Alternative Fuel VehiclesBy James D Halderman and Tony Martin 2009 Pearson Education, Inc.Pearson Prentice HallUpper Saddle River, NJ 07458P-SER
143、IES FUELSP-series fuels are blends of the following:Ethanol (ethyl alcohol)Methyltetrahydrofuron, abbreviated MTHFNatural gas liquids, such as PentanesButaneThe ethanol and MTHF are produced from renewable feed stocks, such as corn, wastes paper, biomass, agricultural waste, and wood waste (scraps a
144、nd sawdust). The components used in P-type fuel can be varied to produce regular grade, premium grade, or fuel suitable for cold climates.Hybrid and Alternative Fuel VehiclesBy James D Halderman and Tony Martin 2009 Pearson Education, Inc.Pearson Prentice HallUpper Saddle River, NJ 07458Composition
145、of P-Series Fuels (by volume)ComponentRegular GradePremium GradeCold WeatherPentanes plus32.5%27.5%16.0%MTHF32.5%17.5%26.0%Ethanol35.0%55.0%47.0%Butane0.0%0.0%11.0%Hybrid and Alternative Fuel VehiclesBy James D Halderman and Tony Martin 2009 Pearson Education, Inc.Pearson Prentice HallUpper Saddle R
146、iver, NJ 07458Alternate Fuel Comparison Chart CharacteristicPropaneCNGMethanolEthanolRegular Unleaded GasOctane10413010010087-93BTU per gallon91,000N.A.70,00083,000114,000-125,000Gallon Equivalent1.15122 cubic feet 1 gallon of gasoline1.81.51On-board fuel storageLiquidGasLiquidLiquidLiquidMiles/gall
147、on as compared to gas85%N.A.55%70%100%Relative tank size required to yield driving range equivalent to gasTank is 1.25 times largerTank is 3.5 times largerTank is 1.8 times largerTank is 1.5 times largerPressure200 psi3000-3600 psiN.A.N.A.N.A.Cold Weather CapabilityGoodGoodPoorPoorGoodVehicle Power5
148、-10% power loss10-20% power loss4% power increase5% power increaseStandardToxicityNontoxicNontoxicHighly toxicToxicToxicCorrosivenessNon-corrosiveNon-corrosiveCorrosiveCorrosiveMinimally corrosiveSourceNatural gas/Petroleum refiningNatural gas/Crude OilNatural gas/CoalSugar and starch crops/BiomassC
149、rude oilHybrid and Alternative Fuel VehiclesBy James D Halderman and Tony Martin 2009 Pearson Education, Inc.Pearson Prentice HallUpper Saddle River, NJ 07458DIESEL FUEL Diesel fuel must meet an entirely different set of standards than gasoline. The fuel in a diesel engine is not ignited with a spar
150、k, but is ignited by the heat generated by high compression. The pressure of compression (400 to 700 PSI or 2800 to 4800 kilopascals) generates temperatures of 1200 to 1600F (700 to 900C), which speeds the pre-flame reaction to start the ignition of fuel injected into the cylinder. All diesel fuel m
151、ust be clean, be able to flow at low temperatures, and be of the proper cetane rating. Hybrid and Alternative Fuel VehiclesBy James D Halderman and Tony Martin 2009 Pearson Education, Inc.Pearson Prentice HallUpper Saddle River, NJ 07458Cleanliness. It is imperative that the fuel used in a diesel en
152、gine be clean and free from water. Unlike the case with gasoline engines, the fuel is the lubricant and coolant for the diesel injector pump and injectors. Good-quality diesel fuel contains additives such as oxidation inhibitors, detergents, dispersants, rust preventatives, and metal deactivators. H
153、ybrid and Alternative Fuel VehiclesBy James D Halderman and Tony Martin 2009 Pearson Education, Inc.Pearson Prentice HallUpper Saddle River, NJ 07458Low-temperature fluidity. Diesel fuel must be able to flow freely at all expected ambient temperatures. One specification for diesel fuel is its pour p
154、oint, which is the temperature below which the fuel would stop flowing. Cloud point is another concern with diesel fuel at lower temperatures. Cloud point is the low-temperature point at which the waxes present in most diesel fuels tend to form wax crystals that clog the fuel filter. Hybrid and Alte
155、rnative Fuel VehiclesBy James D Halderman and Tony Martin 2009 Pearson Education, Inc.Pearson Prentice HallUpper Saddle River, NJ 07458Cetane number. The cetane number for diesel fuel is the opposite of the octane number for gasoline. The cetane number is a measure of the ease with which the fuel ca
156、n be ignited. The cetane rating of the fuel determines, to a great extent, its ability to start the engine at low temperatures and to provide smooth warm-up and even combustion. The cetane rating of diesel fuel should be between 45 and 50. The higher the cetane rating, the more easily the fuel is ig
157、nited. Hybrid and Alternative Fuel VehiclesBy James D Halderman and Tony Martin 2009 Pearson Education, Inc.Pearson Prentice HallUpper Saddle River, NJ 07458The flash point is the temperature at which the vapors on the surface of the fuel will ignite if exposed to an open flame. The flash point does
158、 not affect diesel engine operation. However, a lower-than-normal flash point could indicate contamination of the diesel fuel with gasoline or a similar substance. Hybrid and Alternative Fuel VehiclesBy James D Halderman and Tony Martin 2009 Pearson Education, Inc.Pearson Prentice HallUpper Saddle R
159、iver, NJ 07458ASTM also classifies diesel fuel by volatility (boiling range) into the following grades:Grade #1. This grade of diesel fuel has the lowest boiling point and the lowest cloud and pour points, as well as a lower BTU content less heat per pound of fuel. As a result, grade #1 is suitable
160、for use during low-temperature (winter) operation.Grade #2. This grade has a higher boiling range, cloud point, and pour point as compared with grade #1. It is usually specified where constant speed and high loads are encountered, such as in long-haul trucking and automotive diesel applications.Hybr
161、id and Alternative Fuel VehiclesBy James D Halderman and Tony Martin 2009 Pearson Education, Inc.Pearson Prentice HallUpper Saddle River, NJ 07458Diesel Fuel Specific Gravity TestingThe density of diesel fuel should be tested whenever there is a driveability concern. The density or specific gravity
162、of diesel fuel is measured in units of API gravity. API gravity is an arbitrary scale expressing the gravity or density of liquid petroleum products devised jointly by the American Petroleum Institute and the National Bureau of Standards. The measuring scale is calibrated in terms of degrees API. Oi
163、l with the least specific gravity has the highest API gravity. The formula for determining API gravity is as follows:Degrees API gravity = (141.5 specific gravity at 60F) 131.5The normal API gravity for #1 diesel fuel is 39 to 44 (typically 40).The normal API gravity for #2 diesel fuel is 30 to 39 (
164、typically 35). A hydrometer calibrated in API gravity units should be used to test diesel fuel. Hybrid and Alternative Fuel VehiclesBy James D Halderman and Tony Martin 2009 Pearson Education, Inc.Pearson Prentice HallUpper Saddle River, NJ 07458Hybrid and Alternative Fuel VehiclesBy James D Halderm
165、an and Tony Martin 2009 Pearson Education, Inc.Pearson Prentice HallUpper Saddle River, NJ 07458Diesel Fuel HeatersDiesel fuel heaters, either coolant or electric, help prevent power loss and stalling in cold weather. The heater is placed in the fuel line between the tank and the primary filter. Som
166、e coolant heaters are thermostatically controlled, which allows fuel to bypass the heater once it has reached operating temperature. Hybrid and Alternative Fuel VehiclesBy James D Halderman and Tony Martin 2009 Pearson Education, Inc.Pearson Prentice HallUpper Saddle River, NJ 07458Ultra Low-Sulfur
167、Diesel FuelDiesel fuel is used in diesel engines and is usually readily available throughout the United States, Canada, and Europe, where many more cars are equipped with diesel engines. Diesel engines manufactured to 2007 or newer standards must use ultra low-sulfur diesel fuel containing less than
168、 15 part per million (PPM) of sulfur compared to the older low sulfur specification of 500 PPM. The purpose of the lower sulfur amount in diesel fuel is to reduce emissions of nitrogen oxides (NOx) and particulate matter (PM) from heavy-duty highway engines and vehicles that use diesel fuel. The emi
169、ssion controls used on 2007 and newer diesel engines requires the use of ultra low sulfur diesel (ULSD) for reliable operation. Hybrid and Alternative Fuel VehiclesBy James D Halderman and Tony Martin 2009 Pearson Education, Inc.Pearson Prentice HallUpper Saddle River, NJ 07458Hybrid and Alternative
170、 Fuel VehiclesBy James D Halderman and Tony Martin 2009 Pearson Education, Inc.Pearson Prentice HallUpper Saddle River, NJ 07458Ultra Low Sulfur Diesel (ULSD) will eventually replace the current highway diesel fuel, low sulfur diesel, which can have as much as 500 ppm of sulfur. ULSD is required for
171、 use in all model year 2007 and newer vehicles equipped with advanced emission control systems. ULSD looks lighter in color and has less smell than other diesel fuel. Hybrid and Alternative Fuel VehiclesBy James D Halderman and Tony Martin 2009 Pearson Education, Inc.Pearson Prentice HallUpper Saddl
172、e River, NJ 07458BIODIESELBiodiesel is a domestically produced, renewable fuel that can be manufactured from vegetable oils, animal fats, or recycled restaurant greases. Biodiesel is safe, biodegradable, and reduces serious air pollutants such as particulates (PM), carbon monoxide, and hydrocarbons.
173、 Biodiesel is defined as mono-alkyl esters of long-chain fatty acids derived from vegetable oils or animal fats which conform to ASTM D6751 specifications for use in diesel engines. Biodiesel refers to the pure fuel before blending with diesel fuel. Hybrid and Alternative Fuel VehiclesBy James D Hal
174、derman and Tony Martin 2009 Pearson Education, Inc.Pearson Prentice HallUpper Saddle River, NJ 07458Hybrid and Alternative Fuel VehiclesBy James D Halderman and Tony Martin 2009 Pearson Education, Inc.Pearson Prentice HallUpper Saddle River, NJ 07458Biodiesel blends are denoted as, BXX with XX repre
175、senting the percentage of biodiesel contained in the blend (i.e., B20 is 20% biodiesel, 80% petroleum diesel). Blends of 20% biodiesel with 80% petroleum diesel (B20) can generally be used in unmodified diesel engines; however, users should consult their OEM and engine warranty statement. Hybrid and
176、 Alternative Fuel VehiclesBy James D Halderman and Tony Martin 2009 Pearson Education, Inc.Pearson Prentice HallUpper Saddle River, NJ 07458Bio-diesel has the following characteristics:1. Purchasing biodiesel in bulk quantities decreases the cost of fuel.2. Biodiesel maintains similar horsepower, to
177、rque, and fuel economy. 3. Biodiesel has a higher cetane number than conventional diesel, which increases the engines performance. 4. Biodiesel has a high flash point and low volatility so it does not ignite as easily as petrodiesel, which increases the margin of safety in fuel handling. In fact, it
178、 degrades four times faster than petrodiesel and is not particularly soluble in water. 5. It is nontoxic, which makes it safe to handle, transport, and store. Maintenance requirements for B20 vehicles and petrodiesel vehicles are the same. B100 does pose a few concerns, however. 6. Biodiesel acts as
179、 a lubricant and this can add to the life of the fuel system components. Hybrid and Alternative Fuel VehiclesBy James D Halderman and Tony Martin 2009 Pearson Education, Inc.Pearson Prentice HallUpper Saddle River, NJ 07458E-DIESEL FUELE-diesel, also called diesohol outside of the United States, is
180、standard No. 2 diesel fuel which contains up to 15% ethanol.While E-diesel can have up to 15% ethanol by volume, typical blend levels are from 8% to 10%. Hybrid and Alternative Fuel VehiclesBy James D Halderman and Tony Martin 2009 Pearson Education, Inc.Pearson Prentice HallUpper Saddle River, NJ 0
181、7458SYNTHETIC FUELSSynthetic fuels were first developed using the Fischer-Tropsch method and has been in use since the 1920s to convert coal, natural gas, and other fossil fuel products into a fuel that is high in quality and clean-burning. The process for producing Fischer-Tropsch fuels was patente
182、d by two German scientists, Franz Fischer and Hans Tropsch, during World War I. The Fischer-Tropsch method uses carbon monoxide and hydrogen (the same synthesis gas used to produce hydrogen fuel) to convert coal and other hydrocarbons to liquid fuels in a similar process to hydrogenation, another me
183、thod for hydrocarbon conversion. The process using natural gas, also called gas-to-liquid (GTL) technology, uses a catalyst, usually iron or cobalt, and incorporates steam reforming to give off the byproducts of carbon dioxide, hydrogen, and carbon monoxide. Hybrid and Alternative Fuel VehiclesBy Ja
184、mes D Halderman and Tony Martin 2009 Pearson Education, Inc.Pearson Prentice HallUpper Saddle River, NJ 07458At present, Fischer-Tropsch fuels are very expensive to produce on a large scale, although research is underway to lower processing costs. However, some synthetic diesel fuel is currently bei
185、ng used in South Africa. Diesel fuel created using the Fischer-Tropsch diesel (FTD) process is often called GTL diesel. Hybrid and Alternative Fuel VehiclesBy James D Halderman and Tony Martin 2009 Pearson Education, Inc.Pearson Prentice HallUpper Saddle River, NJ 07458Coal to Liquid (CTL)Coal is ve
186、ry abundant in the United States and coal can be converted to a liquid fuel through a process called coal to liquid (CTL). The huge cost is the main obstacle to these plants. The need to invest $1.4 billion per plant before it can make product is the reason no one has built a CTL plant yet in the Un
187、ited States. Hybrid and Alternative Fuel VehiclesBy James D Halderman and Tony Martin 2009 Pearson Education, Inc.Pearson Prentice HallUpper Saddle River, NJ 07458There are two procedures that can be used to convert coal-to-liquid fuel.1. Direct In the direct method, coal is broken down to create li
188、quid products. First the coal is reacted with hydrogen (H2) at high temperatures and pressure with a catalyst. This process creates a synthetic crude, called syncrude, which is then refined to produce gasoline or diesel fuel.2. Indirect In the indirect method, coal is first turned into a gas and the
189、 molecules reassembled to create the desired product. This process involves turning coal into a gas called syngas. The syngas is then converted into liquid, using the Fischer-Tropsch (FT) process. Hybrid and Alternative Fuel VehiclesBy James D Halderman and Tony Martin 2009 Pearson Education, Inc.Pe
190、arson Prentice HallUpper Saddle River, NJ 07458Hybrid and Alternative Fuel VehiclesBy James D Halderman and Tony Martin 2009 Pearson Education, Inc.Pearson Prentice HallUpper Saddle River, NJ 07458SAFETY PROCEDURES WORKING WITH ALTERNATIVE FUEL VEHICLESAll fuels are flammable and many are explosive
191、under certain conditions. Whenever working around compressed gases of any kind (CNG, LNG, propane, or LPG), always wear personal protective equipment (PPE), including at least the following items:1. Safety glasses and/or face shield2. Protective gloves3. Long-sleeve shirt and pants to help protect b
192、are skin from the freezing effects of gases under pressure in the event that the pressure is lost4. If any fuel gets on the skin, the area should be washed immediately5. If fuel spills on clothing, change into clean clothing as soon as possible6. If fuel spills on a painted surface, flush the surfac
193、e with water and air dry. If simply wiped off with a dry cloth, the paint surface could be permanently damaged.7. As with any fuel burning vehicle, always vent the exhaust to the outside. If methanol fuel is used, the exhaust contains formaldehyde, which has a sharp odor and can cause severe burning
194、 of the eyes, nose, and throat.Do not smoke or have an open flame in the area when working around or refueling any vehicle.Hybrid and Alternative Fuel VehiclesBy James D Halderman and Tony Martin 2009 Pearson Education, Inc.Pearson Prentice HallUpper Saddle River, NJ 07458Step 1 Hybrid and Alternati
195、ve Fuel VehiclesBy James D Halderman and Tony Martin 2009 Pearson Education, Inc.Pearson Prentice HallUpper Saddle River, NJ 07458Step 2 Hybrid and Alternative Fuel VehiclesBy James D Halderman and Tony Martin 2009 Pearson Education, Inc.Pearson Prentice HallUpper Saddle River, NJ 07458Step 3 Hybrid
196、 and Alternative Fuel VehiclesBy James D Halderman and Tony Martin 2009 Pearson Education, Inc.Pearson Prentice HallUpper Saddle River, NJ 07458Step 4 Hybrid and Alternative Fuel VehiclesBy James D Halderman and Tony Martin 2009 Pearson Education, Inc.Pearson Prentice HallUpper Saddle River, NJ 0745
197、8Step 5 Hybrid and Alternative Fuel VehiclesBy James D Halderman and Tony Martin 2009 Pearson Education, Inc.Pearson Prentice HallUpper Saddle River, NJ 07458Step 6 Hybrid and Alternative Fuel VehiclesBy James D Halderman and Tony Martin 2009 Pearson Education, Inc.Pearson Prentice HallUpper Saddle
198、River, NJ 07458SUMMARY1. Gasoline is a complex blend of hydrocarbons. Gasoline is blended for seasonal usage to achieve the correct volatility for easy starting and maximum fuel economy under all driving conditions.2. Winter-blend fuel used in a vehicle during warm weather can cause a rough idle and
199、 stalling because of its higher Reid vapor pressure (RVP).3. Abnormal combustion (also called detonation or spark knock) increases both the temperature and the pressure inside the combustion chamber.4. Most regular-grade gasoline today, using the (R + M) 2 rating method, is 87 octane, midgrade (plus
200、) is 89, and premium grade is 91 or higher.5. Oxygenated fuels contain oxygen in its content to lower CO exhaust emissions.6. Gasoline should always be purchased from a busy station, and the tank should not be overfilled.7. Flexible fuel vehicles are designed to operate on gasoline or E-85.Hybrid an
201、d Alternative Fuel VehiclesBy James D Halderman and Tony Martin 2009 Pearson Education, Inc.Pearson Prentice HallUpper Saddle River, NJ 07458REVIEW QUESTIONS1. What is the difference between summer-blend and winter-blend gasoline?2. What is Reid vapor pressure?3. What is vapor lock?4. What does the (R + M) 2 gasoline pump octane rating indicate?5. What are five octane improvers that may be used during the refining process?6. What is stoichiometric?
