Today, millions of trucks undergo road-bound treks to transport goods. The diesel engines that power these vehicles support this system. These engines, which also are found in buses and some smaller automobiles, require diesel fuel, which needs to adhere to certain specifications.
Rudolf Diesel invented the diesel engine in Powered by a fuel that was considered an unwanted byproduct or distillate of crude oil refining for decades prior, the new engine burned fuel at a lower rate, making better use of the heat generated. It was also was, and still is, safer than gasoline because its vapors did not explode or ignite as easily. Despite its efficiency—diesel contains ten percent more energy per gallon than gasoline— diesel engines did not take off for some time.
Due to issues with environmental and public health, standard forms of diesel fuel have adapted over the years. One of the more recent progressions is the limitation of sulfur content in diesel fuels. As ofa maximum of 15 ppm sulfur in diesel has been the norm for on-road vehicles. It has since been set at that limit for non-road vehicles, locomotives, and marine vessels.
The Chemistry of Diesel Fuel
In general, there are two primary grades of standard diesel fuel : Diesel 1 and Diesel 2. Diesel 2 is general purpose, being able to sustain heavy loads and providing better fuel economy. In fact, No. The two types of oil can be blended. Please note that three of these are variants of Diesel 1, and three are of Diesel 2.
The distinction here is sulfur content, meaning that Grade No. To combat fossil fuel emissions, many trucks now use biodiesel or a biodiesel blend, a fuel comprised of mono-alkyl esters of long chain fatty acids and derived from vegetable oils or animal fats.
This means that diesel importers are required to use a specific volume of biodiesel based on a percentage of its petroleum product sales. In fact, intrucks and other heavy-duty motors in America will burn 3 billion gallons of biodiesel fuel.
This will limit the amount of carbon dioxide emitted into the atmosphere. However, not everyone is pleased with this. ASTM D somewhat discusses biodiesel, but this alternative fuel source is the focus of several other ASTM standards, which are referenced in the document. It covers additional information in its annexes. Your email address will not be published. This site uses Akismet to reduce spam.
Learn how your comment data is processed. Skip to content Diesel Fuel Background Today, millions of trucks undergo road-bound treks to transport goods.Revision This is a preview of the paper, limited to some initial content. Full access requires DieselNet subscription. Please log in to view the complete version of this paper. The beginnings of the petrochemical industry date back to the s.
A few years later, incrude oil was discovered in Pennsylvania in the United States. The first product refined from crude in Pennsylvania was also kerosene, used as lamp oil . Since only a fraction of the crude could be refined into kerosene, the early refiners were left with quantities of petroleum by-products.
These petroleum by-products attracted the attention of Rudolf Diesel, the inventor of compression ignition reciprocating engine. Diesel—whose first engine concept was designed to use coal dust as the fuel—recognized that liquid petroleum products might be better fuels than coal.
The engine was re-designed for operation with liquid fuels, resulting in a successful prototype in Both the engine and the fuel still bear the name of Diesel. Petroleum crude oils are composed of hydrocarbons of three major classes: 1 paraffinic, 2 naphthenic or cycloparaffinicand 3 aromatic hydrocarbons.
Unsaturated hydrocarbons olefins rarely occur in the crude. In modern chemistry, the respective groups of hydrocarbons are called alkanes and cycloalkanes. The composition of the crude can vary from thin light-colored brownish or greenish crude oils of low density, to thick and black oils resembling melted tar.
In the refining process, the crude oil is converted into transportation fuels—gasoline, jet fuel, and diesel fuel—and other petroleum products, such as liquefied petroleum gas LPGheating fuel, lubricating oil, wax, and asphalt.
High-gravity crude oils contain more of the lighter products needed for the production of transportation fuels, and generally have lower sulfur content. Modern refining processes can also convert low-gravity crude oils into lighter products, at an added expense of more complex processing equipment, more processing steps, and more energy. A schematic of modern refinery with diesel streams highlighted is shown in Figure 1 . In the primary distillation column, operating under atmospheric pressure, the crude oil feedstock is separated into a number of streams of increasingly higher boiling point, which are called straight-run products e.
In most refineries, the atmospheric bottoms are further fractionated by a second distillation carried out under vacuum.
The quantity and quality of the streams drawn off from distillation depends on the chemical composition of the crude oil. Crude oils also yield proportions of gasoline, diesel, residual fuel oil, and other products which are usually different from the product demand patterns in particular markets. The only way to balance the refinery production pattern with market demands is through downstream conversion processes. In these conversion processes large hydrocarbon molecules are broken into smaller ones by application of heat, pressure, or catalysts.
Refineries use thermal cracking visbreaking and cokingcatalytic cracking, and hydrocracking also utilizing catalyst, but carried out under a high pressure of hydrogen to increase the yield of desired products by cracking unwanted heavy fractions.
The final products are obtained by blending conversion products crack components with the primary distillation streams. Both blended and straight-run products may require a varying degree of upgrading, to reduce the content of sulfur, nitrogen, and other compounds. A range of processes called hydroprocessing use hydrogen with an appropriate catalyst to upgrade refinery streams.
Hydroprocessing can vary from mild condition hydrofinishing that removes reactive compounds like olefins and some sulfur and nitrogen compounds, to more severe condition hydrotreating that saturates aromatic rings and removes almost all sulfur and nitrogen compounds.
As apparent from Figure 1, diesel fuels used in road transportation are distillate fuelsi. Petroleum residuum materials are contained in heating oils, as well as in marine fuels also known as bunker fuels.
Those products usually have largely different properties from distillate diesel fuels. Abstract : Diesel fuel is a mixture of hydrocarbons obtained by distillation of crude oil. The important properties which are used to characterize diesel fuel include cetane number or cetane indexfuel volatility, density, viscosity, cold behavior, and sulfur content. Diesel fuel specifications differ for various fuel grades and in different countries.Revision This is a preview of the paper, limited to some initial content.
Full access requires DieselNet subscription. Please log in to view the complete version of this paper. Combustion in diesel engines is very complex and until the s, its detailed mechanisms were not well understood. The application of laser-sheet imaging to the conventional diesel combustion process in the s was key to greatly increasing the understanding of this process.
This paper will review the most established combustion model for the conventional diesel engine. This is different from combustion strategies that attempt to significantly increase the proportion of premixed burning that occurs—such as various flavours of low temperature combustion.
The basic premise of diesel combustion is its unique way of releasing the chemical energy stored in the fuel. To perform this process, oxygen must be made available to the fuel in a specific manner to facilitate combustion. One of the most important aspects of this process is the mixing of fuel and air, which is often referred to as mixture preparation. In diesel engines, fuel is often injected into the engine cylinder near the end of the compression stroke, just a few crank angle degrees before top dead center .
The liquid fuel is usually injected at high velocity as one or more jets through small orifices or nozzles in the injector tip. It atomizes into small droplets and penetrates into the combustion chamber. The atomized fuel absorbs heat from the surrounding heated compressed air, vaporizes, and mixes with the surrounding high-temperature high-pressure air.
Rapid ignition of some premixed fuel and air occurs after the ignition delay period. This rapid ignition is considered the start of combustion also the end of the ignition delay period and is marked by a sharp cylinder pressure increase as combustion of the fuel-air mixture takes place.
Increased pressure resulting from the premixed combustion compresses and heats the unburned portion of the charge and shortens the delay before its ignition. It also increases the evaporation rate of the remaining fuel. Atomization, vaporization, fuel vapor-air mixing, and combustion continue until all the injected fuel has combusted. Therefore, excess air present in the cylinder after the fuel has combusted continues to mix with burning and already burned gases throughout the combustion and expansion processes.
At the opening of the exhaust valve, excess air along with the combustion products are exhausted, which explains the oxidizing nature of diesel exhaust. In other words, the majority of the air inducted into the cylinder of a diesel engine is compressed and heated, but never engages in the combustion process.
Oxygen in the excess air helps oxidize gaseous hydrocarbons and carbon monoxide, reducing them to extremely small concentrations in the exhaust gas. While these two factors are most important, there are other parameters that may dramatically influence them and therefore play a secondary, but still important role in the combustion process. For instance:. It is therefore important to realize that the combustion system of the diesel engine is not limited to the combustion bowl, injector sprays, and their immediate surroundings.
Rather, it includes any part, component, or system that may affect the final outcome of the combustion process. Abstract : In diesel engines, fuel is injected into the engine cylinder near the end of the compression stroke. During a phase known as ignition delay, the fuel spray atomizes into small droplets, vaporizes, and mixes with air. The balance of fuel that had not participated in premixed combustion is consumed in the rate-controlled combustion phase.Composition of gasoline and diesel.
Both gasoline and diesel fuel consist of hundreds of different hydrocarbon molecules. In addition, several bio-origin components, such as ethanol in gasoline blending, are common.
Gasoline contains mainly alkanes paraffinsalkenes olefinsand aromatics. Diesel fuel consists mainly of paraffins, aromatics and naphthenes. Paraffinic hydrocarbons, especially normal paraffins, improve ignition quality of diesel fuel, but low-temperature properties of these paraffins tend to be poor.
Aromatics in gasoline have high octane numbers. However, aromatics and olefins may worsen engine cleanliness, and also increase engine deposits, which is an important factor for new sophisticated engines and after-treatment devices.
Aromatics may lead to carcinogenic compounds in exhaust gases, such as benzene and polyaromatic compounds. Olefins in gasoline may lead to an increase in the concentration of reactive olefins in exhaust gases, some of which are carcinogenic, toxic or may increase ozone forming potential. Additives may be needed to ensure adequate properties of gasoline and diesel fuel. Instead, focus is given to alternative blending or replacement options of gasoline and diesel. However, engine technology together with legislation and standards for gasoline and diesel are discussed briefly.
Gasoline — legislation and standards. The engine and after-treatment technology impose requirements on fuel quality. Basic fuel analyses were developed to screen general performance and operability of fuels in internal combustion engines. Fuel properties important in environmental contexts, such as compatibility of fuel with emission control devices, were defined subsequently.
The functionality and general performance of gasoline can be defined, for example, in terms of octane rating, volatility, olefin content, and additives. Environmental performance can be defined, for example, in terms of aromatics, olefins, benzene content, oxygenates, volatility, and sulfur lead is not allowed in most countries.
Fuel properties are controlled by legislation and by fuel standards. There are also a number of other regional and national standards on fuels.
The European standard EN includes more extensive requirements than Fuel Quality Directive to ensure proper functionality of gasoline on market. The ASTM standard includes a number of classes, waivers, and exceptions taking into account climate, region and, for example, ethanol content of gasoline. The fuel must contain no more than 2. Table 1.This application claims benefit under 35 U. Provisional Patent Application No.
This application claims priority to and benefits from the foregoing, the disclosure of which is incorporated herein by reference. The present invention relates to fuel compositions. More specifically, it relates to diesel fuel compositions that contain no more than 30 ppm of active detergent additive or active dispersant additive or mixtures thereof. Diesel engines have been used in applications such as stationary power generation, locomotives, ships, trucks, and automobiles.
These engines, unlike gasoline engines, lack an ignition source, i. Air is compressed to high pressure resulting in sufficiently high temperature to cause auto-ignition when diesel fuel is introduced into the combustion chamber. Fuel injectors, therefore, are a significant element in the system to deliver fuel to the engine. Proper operation of the fuel injector is critical to the smooth operation of the engine for optimum power, fuel consumption, and emissions control. Optimized operation relies on precise injection timing, fuel volume delivery, and designed spray pattern.
Diesel fuel has the tendency to form solid deposits in many engine applications at high temperature. Carbon deposits, if not controlled, build up at the injector nozzle tip and lead to restricted flow volume and spray pattern.
Larger fuel droplets in the combustion chamber require more time to burn efficiently. Lacking sufficient timing, fuel economy and emissions are affected adversely. Detergent additives are commonly employed in diesel fuels to minimize or eliminate fuel injector nozzle tip carbon deposits. It has now been found that diesel engine injector deposits can be reduced or eliminated by use of diesel fuel stability and antioxidant additives.
The present invention is directed to a fuel composition comprising a major amount of hydrocarbons boiling in the diesel range and an effective deposit-controlling amount of at least one stability additive or at least one antioxidant additive or mixtures thereof, and wherein the fuel composition contains no more than 30 ppm of active detergent additive or active dispersant additive or mixtures thereof.
The present invention is directed to a method of reducing injector deposits in a direct injection diesel engine comprising supplying a fuel composition comprising a major amount of hydrocarbons boiling in the diesel range and an effective deposit-controlling amount of at least one stability additive or at least one antioxidant additive or mixtures thereof, and wherein the fuel composition contains no more than 30 ppm of active detergent additive or active dispersant additive or mixtures thereof to an internal combustion engine.
The present invention further provides a fuel composition comprising a major amount of hydrocarbons boiling in the diesel range and an effective deposit-controlling amount of a fuel additive composition of the present invention. The present invention also provides a method of improving the compatibility of a fuel additive composition comprising blending together the components of the fuel additive composition of the present invention.Diesel fuel is the common term for the petroleum distillate fuel oil sold for use in motor vehicles that use the compression ignition engine named for its inventor, German engineer Rudolf Diesel.
He patented his original design in One of the fuels that Rudolf Diesel originally considered for his engine was vegetable seed oil, an idea that eventually contributed to biodiesel production and use today. Diesel fuel is refined from crude oil at petroleum refineries. Beforemost diesel fuel sold in the United States contained high quantities of sulfur. Sulfur in diesel fuel produces air pollution emissions that are harmful to human health. Inthe U. Environmental Protection Agency issued requirements to reduce the sulfur content of diesel fuel sold for use in the United States.
The requirements were phased in over time, beginning with diesel fuel sold for vehicles used on roadways and eventually including all non-road diesel fuel. Diesel fuel now sold in the United States for on-highway use is ultra-low sulfur diesel ULSDwhich has a sulfur content of 15 parts per million or less.
Most diesel fuel sold for off-highway or non-road use is also ULSD. Click to enlarge. Most freight and delivery trucks as well as trains, buses, boats, and farm, construction, and military vehicles have diesel engines.
Some small trucks and cars also have diesel engines. Diesel fuel is also used in diesel engine generators to generate electricity, such as in remote villages in Alaska, among other locations around the world.
Many industrial facilities, large buildings, institutional facilities, hospitals, and electric utilities have diesel generators for backup and emergency power supply. Indistillate fuel essentially diesel fuel consumption by the U. Diesel fuel explained. What is energy? Units and calculators. Use of energy. Energy and the environment.
Also in What is energy? Forms of energy Sources of energy Laws of energy. Also in Units and calculators explained Units and calculators Energy conversion calculators British thermal units Btu Degree days. Also in U. Also in Use of energy explained Use of energy Energy use in industry Energy use for transportation Energy use in homes Energy use in commercial buildings Energy efficiency and conservation.
Also in Energy and the environment explained Energy and the environment Greenhouse gases Greenhouse gases and the climate Where greenhouse gases come from Outlook for future emissions Recycling and energy.
Nonrenewable sources. Oil and petroleum products. Diesel fuel. Heating oil. Also in Oil and petroleum products explained Oil and petroleum products Refining crude oil Where our oil comes from Imports and exports Offshore oil and gas Use of oil Prices and outlook Oil and the environment. Also in Gasoline explained Gasoline Octane in depth Where our gasoline comes from Use of gasoline Prices and outlook Factors affecting gasoline prices Regional price differences Price fluctuations History of gasoline Gasoline and the environment.Diesel fuelalso called diesel oilcombustible liquid used as fuel for diesel enginesordinarily obtained from fractions of crude oil that are less volatile than the fractions used in gasoline.
In diesel engines the fuel is ignited not by a spark, as in gasoline enginesbut by the heat of air compressed in the cylinder, with the fuel injected in a spray into the hot compressed air. Diesel fuel releases more energy on combustion than equal volumes of gasoline, so diesel engines generally produce better fuel economy than gasoline engines. In addition, the production of diesel fuel requires fewer refining steps than gasoline, so retail prices of diesel fuel traditionally have been lower than those of gasoline depending on the location, season, and taxes and regulations.
On the other hand, diesel fuel, at least as traditionally formulated, produces greater quantities of certain air pollutants such as sulfur and solid carbon particulates, and the extra refining steps and emission-control mechanisms put into place to reduce those emissions can act to reduce the price advantages of diesel over gasoline.
In addition, diesel fuel emits more carbon dioxide per unit than gasoline, offsetting some of its efficiency benefits with its greenhouse gas emissions. Performance criteria are cetane number a measure of ease of ignitionease of volatilization, and sulfur content. The highest grades, for automobile and truck engines, are the most volatile, and the lowest grades, for low-speed engines, are the least volatile, leave the most carbon residue, and commonly have the highest sulfur content.
Sulfur is a critical polluting component of diesel and has been the object of much regulation. Lower sulfur content reduces emissions of sulfur compounds implicated in acid rain and allows diesel vehicles to be equipped with highly effective emission-control systems that would otherwise be damaged by higher concentrations of sulfur.
Heavier grades of diesel fuel, made for use by off-road vehicles, ships and boats, and stationary engines, are generally allowed higher sulfur content, though the trend has been to reduce limits in those grades as well.
In addition to traditional diesel fuel refined from petroleumit is possible to produce so-called synthetic diesel, or Fischer-Tropsch diesel, from natural gasfrom synthesis gas derived from coal see coal utilizationor from biogas obtained from biomass.
Also, biodiesela biofuelcan be made primarily from oily plants such as the soybean or oil palm. These alternative diesel fuels can be blended with traditional diesel fuel or used alone in diesel engines without modification, and they have very low sulfur content. Alternative diesel fuels are often proposed as means to reduce dependence on petroleum and to reduce overall emissions, though only biodiesel can provide a life cycle carbon dioxide benefit. Seven grades of diesel fuel specified by the American Society of Testing and Materials are shown in the table.
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