Differences Between Kerosene and Diesel

Kerosene and diesel is part of crude oil’s byproducts as a result of the refining process. Crude oil, also called petroleum, is extracted from the ground and then taken to the refinery stage where several molecular constituents will be derived. Among others, lies the diesel and kerosene which are often confused by some people. As a result, people tend to use these fuels interchangeably. While these are byproducts of crude oil, they differ in physical and chemical properties, and the interchangeable use may tend out to be inefficient in custom applications. This article brings the distinction between kerosene and diesel.

                                 

kerosene

Kerosene, also known as paraffin, lamp oil, and coal oil (an obsolete term), is a combustible hydrocarbon liquid which is derived from petroleum. It is widely used as a fuel in aviation as well as households. Its name derives from Greek: (keros) meaning "wax", and was registered as a trademark by Canadian geologist and inventor Abraham Gesner in 1854 before evolving into a genericized trademark. It is sometimes spelled kerosine in scientific and industrial usage. The term kerosene is common in much of Nigeria, Ghana, Argentina, Australia, Canada, India, New Zealand, and the United States. Liquid paraffin (called mineral oil in the US) is a more viscous and highly refined product that is used as a laxative. Paraffin wax is a waxy solid extracted from petroleum.

Kerosene is widely used to power jet engines of aircraft (jet fuel) and some rocket engines and is also commonly used as a cooking and lighting fuel, and for fire toys such as poi. In parts of Asia, kerosene is sometimes used as fuel for small outboard motors or even motorcycles.

Properties

Kerosene is a low viscosity, clear liquid formed from hydrocarbons obtained from the fractional distillation of petroleum between 150 and 275 °C (300 and 525 °F), resulting in a mixture with a density of 0.78–0.81 g/cm3 (0.45–0.47 oz/cu in) composed of carbon chains that typically contain between 10 and 16 carbon atoms per molecule.

 It is miscible in petroleum solvents but immiscible in water.

The distribution of hydrocarbon length in the mixture making up kerosene ranges from a number of carbon atoms of C6 to C20, although typically kerosene predominantly contains C9 to C16 range hydrocarbons.

The ASTM International standard specification D-3699-78 recognizes two grades of kerosene: grades 1-K (less than 0.04% sulfur by weight) and 2-K (0.3% sulfur by weight). 1-K grade kerosene burns cleaner with fewer deposits, fewer toxins, and less frequent maintenance than 2-K grade kerosene, and is the preferred grade of kerosene for indoor kerosene heaters and stoves.

Irrespective of crude oil source or processing history, kerosene's major components are branched and straight-chain alkanes and naphthenes (cycloalkanes), which normally account for at least 70% by volume.

Aromatic hydrocarbons in this boiling range, such as alkylbenzenes (single ring) and alkyl naphthalenes (double ring), do not normally exceed 25% by volume of kerosene streams. Olefins are usually not present at more than 5% by volume.

The flash point of kerosene is between 37 and 65 °C (100 and 150 °F), and its autoignition temperature is 220 °C (428 °F).

The freeze point of kerosene depends on the grade, with commercial aviation fuel standardized at −47 °C (−53 °F).

1-K grade kerosene freezes around −40 °C (−40 °F, 233 K).

Heat of combustion of kerosene is similar to that of diesel fuel; its lower heating value is 43.1 MJ/kg (around 18,500 Btu/lb), and its higher heating value is 46.2 MJ/kg (19,900 Btu/lb).

Uses

The fuel, also known as heating oil in the UK and Ireland, remains widely used in kerosene lamps and lanterns in the developing world. Although it replaced whale oil, the 1873 edition of Elements of Chemistry said, "The vapor of this substance [kerosene] mixed with air is as explosive as gunpowder."

In less-developed countries kerosene is an important source of energy for cooking and lighting. It is used as a cooking fuel in portable stoves for backpackers. As a heating fuel, it is often used in portable stoves and is sold in some filling stations. It is sometimes used as a heat source during power failures.

Cooking

In countries such as India and Nigeria, kerosene is the main fuel used for cooking, especially by the poor, and kerosene stoves have replaced traditional wood-based cooking appliances. As such, an increase in the price of kerosene can have a major political and environmental consequence. Kerosene is used as a fuel in portable stoves.

Engines

In the early to mid-20th century, kerosene or tractor vaporizing oil (TVO) was used as a cheap fuel for tractors and hit 'n miss engines The engine would start on gasoline, then switch over to kerosene once the engine warmed up. On some engines a heat valve on the manifold would route the exhaust gases around the intake pipe, heating the kerosene to the point where it was vaporized and could be ignited by an electric spark.

Kerosene is used to fuel smaller-horsepower outboard motors built by Yamaha, Suzuki, and Tohatsu. Primarily used on small fishing craft, these are dual-fuel engines that start on gasoline and then transition to kerosene once the engine reaches optimum operating temperature.

Today, kerosene is mainly used in fuel for jet engines in several grades. One highly refined form of the fuel is known as RP-1, and is often burned with liquid oxygen as rocket fuel. These fuel grade kerosenes meet specifications for smoke points and freeze points. The combustion reaction can be approximated as follows, with the molecular formula C12H26 (dodecane):

2 C12H26(l) + 37 O2(g) → 24 CO2(g) + 26 H2O(g); ∆H˚ = -7513 kJ

In the initial phase of liftoff, the Saturn V launch vehicle was powered by  the reaction of liquid oxygen with RP-1.[45] For the five 6.4 meganewton sea-level thrust F-1 rocket engines of the Saturn V, burning together, the reaction generated roughly 1.62 × 1011 watts (J/s) (162 gigawatt) or 217 million horsepower.

Kerosene is sometimes used as an additive in diesel fuel to prevent gelling or waxing in cold temperatures.

In chemistry

Kerosene is used as a diluent in the PUREX extraction process, but it is increasingly being supplanted by dodecane. In X-ray crystallography, kerosene can be used to store crystals. When a hydrated crystal is left in the air, dehydration may occur slowly. This makes the color of the crystal become dull. Kerosene can keep air from the crystal.

It can be also used to prevent air from re-dissolving in a boiled liquid, and to store alkali metals such as potassium, sodium, and rubidium (with the exception of lithium, which is less dense than kerosene, causing it to float).

Kerosene vapor diffused in the air (as from a lamp wick) will burn at a maximum flame temperature of 990 °C (1814 °F). In a stoichiometric mixture with oxygen, the flame temperature of kerosene can reach 2393 °C (3801 °F).

In entertainment

Kerosene is often used in the entertainment industry for fire performances, such as fire breathing, fire juggling or poi, and fire dancing. Because of its low flame temperature when burnt in free air, the risk is lower should the performer come in contact with the flame. Kerosene is generally not recommended as fuel for indoor fire dancing, as it produces an unpleasant (to some) odor, which becomes poisonous in sufficient concentration. Ethanol was sometimes used instead, but the flames it produces look less impressive, and its lower flash point poses a high risk.

In industry

As a petroleum product miscible with many industrial liquids, kerosene can be used as both a solvent, able to remove other petroleum products, such as chain grease, and as a lubricant, with less risk of combustion when compared to using gasoline. It can also be used as a cooling agent in metal production and treatment (oxygen-free conditions). In the petroleum industry, kerosene is often used as a synthetic hydrocarbon for corrosion experiments to simulate crude oil in field conditions.

Others

Kerosene can be applied topically to hard-to-remove mucilage or adhesive left by stickers on a glass surface (such as in show windows of stores).

It can be used to remove candle wax that has dripped onto a glass surface; it is recommended that the excess wax be scraped off prior to applying kerosene via a soaked cloth or tissue paper.

It can be used to clean bicycle and motorcycle chains of old lubricant before re-lubrication.

It can also be used to thin oil-based paint used in fine art. Some artists even use it to clean their brushes; however, it leaves the bristles greasy to the touch

Toxicity

Ingestion of kerosene is harmful or fatal. Kerosene is sometimes recommended as a folk remedy for killing head lice, but health agencies warn against this as it can cause burns and serious illness. A kerosene shampoo can even be fatal if fumes are inhaled.

People can be exposed to kerosene in the workplace by breathing it in, swallowing it, skin contact, and eye contact. The US National Institute for Occupational Safety and Health (NIOSH) has set a recommended exposure limit of 100 mg/m3 over an 8-hour workday.

Diesel

Diesel fuel in the general is any liquid fuel used in diesel engines, whose fuel ignition takes place, without any spark, as a result of compression of the inlet air mixture and then injection of fuel. It does not mix with water. (Glow plugs, grid heaters and block heaters help to achieve high temperatures for combustion during engine startup in cold weather.) Diesel engines have found broad use as a result of higher thermodynamic efficiency and thus fuel efficiency. This is particularly noted where diesel engines are run at part-load; as their air supply is not throttled as in a petrol engine, their efficiency still remains very high.

The most common type of diesel fuel is a specific fractional distillate of petroleum fuel oil, but alternatives that are not derived from petroleum, such as biodiesel, biomass to liquid (BTL) or gas to liquid (GTL) diesel, are increasingly being developed and adopted. To distinguish these types, petroleum-derived diesel is increasingly called petrodiesel. Ultra-low-sulfur diesel (ULSD) is a standard for defining diesel fuel with substantially lowered sulfur contents.

Types

Diesel fuel is produced from various sources, the most common being petroleum. Other sources include biomass, animal fat, biogas, natural gas, and coal liquefaction.

Petroleum diesel

Petroleum diesel, also called petrodiesel, or fossil diesel is the most common type of diesel fuel. It is produced from the fractional distillation of crude oil between 200 °C (392 °F) and 350 °C (662 °F) at atmospheric pressure, resulting in a mixture of carbon chains that typically contain between 9 and 25 carbon atoms per molecule.

Synthetic diesel

Synthetic diesel can be produced from any carbonaceous material, including biomass, biogas, natural gas, coal, and many others.

Biodiesel

Biodiesel made from soybean oil

Fatty-acid methyl ester (FAME), more widely known as biodiesel, is obtained from vegetable oil or animal fats (biolipids) which have been transesterified with methanol. It can be produced from many types of oils, the most common being rapeseed oil (rapeseed methyl ester, RME) in Europe and soybean oil (soy methyl ester, SME) in the US. Methanol can also be replaced with ethanol for the transesterification process.

Hydrogenated oils and fats

This category of diesel fuels involves converting the triglycerides in vegetable oil and animal fats into alkanes by refining and hydrogenation, such as H-Bio. The produced fuel has many properties that are similar to a synthetic diesel, and are free from the many disadvantages of FAME.

DME

Dimethyl ether, DME, is a synthetic, gaseous diesel fuel that results in clean combustion with very little soot and reduced NOx emissions.

Uses

Diesel uses less fuel than rich burn spark ignition engines which use a stoichiometric air-fuel ratio (just enough air to react with the fuel).

The viscosity requirement of diesel fuel is usually specified at 40 °C. A disadvantage of diesel as a vehicle fuel in cold climates is that its viscosity increases as the temperature decreases, changing it into a gel (see Compression Ignition – Gelling) that cannot flow in fuel systems. Special low-temperature diesel contains additives to keep it liquid at lower temperatures, but starting a diesel engine in very cold weather may still pose considerable difficulties. Another disadvantage of diesel engines compared to petrol/gasoline engines is the possibility of diesel engine runaway failure. Since diesel engines do not need spark ignition, they can run as long as diesel fuel is supplied. Fuel is typically supplied via a fuel pump. With turbocharged engines, the oil seals on the turbocharger may fail, allowing lubricating oil into the combustion chamber, where it is burned like regular diesel fuel.

Trucks

Diesel fuel is widely used in most types of transportation.

Railroad

Diesel displaced coal and fuel oil for steam-powered vehicles in the latter half of the 20th century, and is now used almost exclusively for the combustion engines of self-powered rail vehicles (locomotives and railcars).

Aircraft

Diesel engines for airships were developed in both Germany and the United Kingdom by Daimler-Benz and Beardmore.

Military vehicles

Armored fighting vehicles use diesel because of its lower flammability risks and the engines' higher provision of torque and a lower likelihood of stalling.

Cars

Diesel-powered cars generally have a better fuel economy than equivalent gasoline engines and produce less greenhouse gas emissions.

Tractors and heavy equipment

Today's tractors and heavy equipment are mostly diesel-powered. Among tractors, only the smaller classes may also offer gasoline engines.

Other uses

Poor quality diesel fuel has been used as an extraction agent for liquid-liquid extraction of palladium from nitric acid mixtures.

Diesel fuel is also often used as the main ingredient in the oil-base mud drilling fluid. The advantage of using diesel is its low cost and its ability to drill a wide variety of difficult strata, including shale, salt, and gypsum formations. Diesel-oil mud is typically mixed with up to 40% brine water. Due to health, safety, and environmental concerns, Diesel-oil mud is often replaced with vegetable, mineral, or synthetic food-grade oil-base drilling fluids, although diesel-oil mud is still in widespread use in certain regions.

Chemical composition

Petroleum-derived diesel is composed of about 75% saturated hydrocarbons (primary paraffin including n, iso, and cycloparaffins), and 25% aromatic hydrocarbons (including naphthalenes and alkylbenzenes). The average chemical formula for common diesel fuel is C12H24, ranging approximately from C10H20 to C15H28.

Summary of Diesel versus Kerosene

Diesel and kerosene are both crude oil byproducts separated by distillation process due to boiling points difference.

Because of Diesel high boiling point, it is extracted after kerosene.

Kerosene is colorless but can also be dyed blue. And Diesel is a reddish fuel.

Kerosene is used in home heating and cooling systems or old lamps whereas diesel is used largely in industries and automobiles word-wide.