1. Petroleum 2. INDEX 2). Formation of petroleum 3). History of petroleum 5). 3. What is Petroleum?In a lay man‘s language, PETROLEUM is FUEL.Fuels are materials that give off heat when they are burned. A fuelmay be a solid, a liquid, or a gas. Fuels that come from theremains of living things are called fossil fuels. Wood, coal, naturalgas and the liquid fuel petroleum are common fossil. 4. TYPES OF ENERGY – THE FUEL OF LIFE 5. Consumption of Energy by MankindPetroleum is energy, stored deep in the earth by nature. This isa non- renewable energy source because petroleum suppliesare limited and they draw on finite resources that willeventually dwindle. Petroleum includes crude oil, condensateand natural gas. 6. How is Petroleum formed?Petroleum is made primarily ofmixtures ofhydrocarbons, compounds ofcarbon, and hydrogen.Scientists believe petroleumhydrocarbons come from theremains of tiny animals andplants that lived millions ofyears ago.The idea that oil was created from dinosaurs is a myth, there simply werenot enough of them to create such large amounts of oil. 7. STAGE 1When tiny organisms die, they sink to the bottom of the sea and are mixed with mud and silt. 8. STAGE III STAGE II Lack of oxygen at the bottom of sea keeps the Bacteria removes most animals and plants from of the decaying completely.oxygen, nitrogen, phosp The partially horus, and decomposed organisms sulfur, leaving mainly create a slimy mass, hydrogen and carbon. which is then covered. with layers of sediments. 9. STAGE IVOver millions of years, many layers of sedimentpile on top of the once-living organisms. When the depth of burial reaches about 10,000 feet, natural heat of the earth and intense pressure combine to act upon the mass. The end result, over time, is the formation of petroleum 10. Petroleum deposits are locked in porous rocks almost likewater is trapped in a wet sponge .When crude oil comes out ofthe ground , it can be as thin as water or as thick as tar. 11. The first Petroleum Well Petroleum was discovered at a shallow depth of only 21 metres through ―Drake‘s well‖ The first petroleum was drilled in Pennsylvania, USA in 1859. Early modern discoveries of petroleum relied on these small surface wells. In the United States, bores that were used for water began producing crude oil. At that time, petroleum was called coal oil. The discovery of petroleum eventually closed the nineteenth century whale-oil industry.You could say that the oil and gas industry has helped to save the whale! 12. WHO FINDS PETROLEUM AND WHERE? 13. FINDING PETROLEUM WAS ONCE A JOB FOR PROSPECTORS WHO DUG WELLS INPLACES THAT THEY THOUGHT WOULD BE SUITABLE - PERHAPS A LINE OF HILLS OR ASWAMP. SO THEY DRILLED A HOLE THERE AND IT WAS KNOWN AS A ―WILD-CAT‖ WELL.BUT THE DEMAND FOR PETROLEUM BECAME TOO GREAT TO RELY ON GUESSWORK.WILD-CAT PROSPECTORS HAD TO GIVE WAY TO SPECIALIST SCIENTISTS. THESESCIENTISTS ARE GEOLOGISTS AND GEOPHYSICISTS. 14. GEOLOGISTS INTERESTED IN SEDIMENTARY ROCKS. THESE ARE CALLED SEDIMEN- TOLOGISTS. GEOLOGISTS STUDYING FOSSILS ARE CALLED PALAEONTOLOGISTS.GEOLOGISTSSTUDY ROCKS AND GEOLOGISTSSOILS IN THE SPECIALISING IN THE CHEMISTRY OF ROCKSLAYERS OF THE AND THE FLUIDS THEY CONTAIN ARE GEOCHEMISTS.EARTH‘S CRUST GEOPHYSICISTS STUDY AND MEASURE THE PHYSICAL PHENOMENA OF THE EARTH. THEY MEASURE TEMPERATURE, MAGNETI SM, EARTH MOVEMENTS, WATER FLOW, ASSESS EARTHQUAKES. 15. The Geologists work togetherwith 3 objectives FIRST, TO IMPROVE OUR KNOWLEDGE AND UNDERSTANDING OF THE EARTH (WHAT IT IS AND WHAT MAKES IT TICK). SECOND, TO FIND OUT WHAT IS THE NATURE OF THE EARTH FOR THE CONSTRUCTION OF TUNNELS, BUILDINGS, POWER STATIONS AND OTHER STRUCTURES. AND THIRD, TO EXPLORE THE EARTH FOR PETROLEUM, NATURAL GAS AND MINERALS, AND TO ESTABLISH WHETHER THESE ARE SUITABLE FOR COMMERCIAL EXPLOITATION. 16. Of every 100 new wells drilledonly about 44 produce oil.When scientists think theremay be oil in a certainplace, a petroleum companybrings in a drilling rig andthey need to drill a well.The typical oil well is aboutone mile deep. 17. Petroleum is found in threeforms: as a solid, calledbitumen; as a liquid, whichis usually called crude oil orcondensate; and as agas, such as methane and ethane.Both liquid oil and naturalgas are generally foundtogether.Whether a discoverybecomes an oil or a gas fielddepends solely on whetherthere is more of one fossilfuel or the other fossil fuelin the area. 18. We can‘t use crude oil as itcomes out of the ground.We must change it intofuels that we can use. Thefirst stop for crude oil is atan oil refinery. A refinery isa factory that processes oil.The refinery cleans andseparates the crude oil intomany fuels and products.The most important one isgasoline. Other petroleumproducts are dieselfuel, heating oil, and jetfuel. Industry usespetroleum to make plasticsand many other products. 19. Petroleum Producing States 20. Major Petroleum ProductsInk Hand lotion DashboardsHeart valves Toothbrushes LuggageCrayons Guitar strings DVD‘sParachutes Movie film BalloonsEnamel Aspirin Paint brushesAntiseptics Sunglasses FootballsPurses Glue DyesDeodorants Artificial limbs AntihistaminesPantyhose Ballpoint pens SkisOil filters Golf balls PerfumesPajamas Contact lenses Shoe PolishCassettes Dice FertilizersFishing Rods Trash bags InsecticidesElectrical tapes Shampoo Cold CreamFloor wax Cameras DetergentsTires Toothpaste Nail polish 21. Oil and the EnvironmentPetroleum products –gasoline, medicines, fertilizers, and others havehelped people all over the world. But there is a trade-off. If drilling is not carefully regulated, it may disturb fragile land and ocean environments. Petroleum production and petroleum products may cause air and water pollution. Transporting oil may endanger wildlife if it‘s spilled on rivers and oceans. Burning gasoline to fuel our car pollutes the air. Even the careless deposal of motor oil drained from the family car can pollute streams and rivers. 22. Fuel for thoughtPhd scholar at the Center Energy and Environment, TERI University,Aditi Banerjee is currently pursuing her research in the area of biomassutilization for ethanol production . There has been widespread concernover global warming and climate change caused by use the use of fossilfuels. In this regard, biofuels like bioethanol and biodiesel have emergedas a sustainable and greener alternative in fossil fuels.Ethanol is a type of an alcohol, used in whisky, bear, rum, wine, etc.However, ethanol can also be blended with petrol as a fuel additive tomake it more fuel efficient and help reduce air pollution. Generally,ethanol is produced from sugarcane molasses ( a waste stream forsugar production factory). But it‘s not an adequate source to meet therising demand for ethanol production which Is required to blend withpetrol. Therefore, new source or feedstocks are explored for productionof ethanol.
A candle is a solid block of wax with an embedded wick, which is ignited to provide light, and sometimes heat, and historically was used as a method of keeping time.
A candle manufacturer is traditionally known as a chandler.[1] Various devices have been invented to hold candles, from simple tabletop candle holders, to elaborate chandeliers.[2]
For a candle to burn, a heat source (commonly a naked flame) is used to light the candle's wick, which melts and vaporizes a small amount of fuel, the wax. Once vaporized, the fuel combines with oxygen in the atmosphere to form a flame. This flame provides sufficient heat to keep the candle burning via a self-sustaining chain of events: the heat of the flame melts the top of the mass of solid fuel; the liquefied fuel then moves upward through the wick via capillary action; the liquefied fuel finally vaporizes to burn within the candle's flame.
As the mass of solid fuel is melted and consumed, the candle grows shorter. Portions of the wick that are not emitting vaporized fuel are consumed in the flame. The incineration of the wick limits the exposed length of the wick, thus maintaining a constant burning temperature and rate of fuel consumption. Some wicks require regular trimming with scissors (or a specialized wick trimmer), usually to about one-quarter inch (~0.7 cm), to promote slower, steady burning, and also to prevent smoking. In early times, the wick needed to be trimmed quite frequently, and special candle-scissors, referred to as "snuffers" until the 20th century, were produced for this purpose, often combined with an extinguisher. In modern candles, the wick is constructed so that it curves over as it burns (see picture on the right), so that the end of the wick gets oxygen and is then consumed by fire—a self-trimming wick.[3]
Components
Wax[
The hydrocarbon C31H64 is a typical component of paraffin wax, from which most modern candles are produced.
Unlit candles
Candles were once made from tallow and beeswax until after about 1850, they were made mainly from spermaceti and purified animal fats (stearin). Today, most candles are made from paraffin wax.[4] Candles can also be made from beeswax, soy, other plant waxes, and tallow (a by-product of beef-fat rendering). Gel candles are made from a mixture of mineral oil and a polymer.[5]
The candle can be made of
paraffin (a product of petroleum refining) microcrystalline wax stearin (now produced almost exclusively from palm waxes though initially manufactured from animal fats) beeswax (a byproduct of honey collection) gel (a mixture of polymer and mineral oil) some plant waxes (generally palm, carnauba, bayberry, or soybean wax) tallow (rarely used since the introduction of affordable and cheap wax alternatives) spermaceti (extracted from the head of a Sperm Whale)
The size of the flame and corresponding rate of burning is controlled largely by the candle wick.
Production methods utilize extrusion moulding.[4] More traditional production methods entails melting the solid fuel by the controlled application of heat. The liquid is then poured into a mould or a wick is repeatedly immersed in the liquid to create a dipped tapered candle. Often fragrance oils, essential oils or aniline-based dye is added.
Wick[edit source | editbeta]
Main article: Candle wick
A candle wick works by capillary action, drawing ("wicking") the melted wax or fuel up to the flame. When the liquid fuel reaches the flame, it vaporizes and combusts. The candle wick influences how the candle burns. Important characteristics of the wick include diameter, stiffness, fire-resistance, and tethering.
A candle wick is a piece of string or cord that holds the flame of a candle. Commercial wicks are made from braided cotton. The wick's capillarity determines the rate at which the melted hydrocarbon is conveyed to the flame. If the capillarity is too great, the molten wax streams down the side of the candle. Wick are often infused with a variety of chemicals to modify its burning characteristics. For example, it is usually desirable that the wick not glow after the flame is extinguished. Typical agents are ammonium nitrate and ammonium sulfate.[4]
Characteristics[edit source | editbeta]
Light[edit source | editbeta]
A room lit up in the glow of many candles
Based on measurements of a taper-type, paraffin wax candle, a modern candle typically burns at a steady rate of about 0.1 g/min, releasing heat at roughly 80 W.[6] The light produced is about 13 lumens, for a luminous efficacy of about 0.16 lumens per watt (luminous efficacy of a source) - almost a hundred times lower than an incandescent light bulb.
The luminous intensity of a typical candle is thus approximately one candela. The SI unit, candela, was in fact based on an older unit called the candlepower, which represented the luminous intensity emitted by a candle made to particular specifications (a "standard candle"). The modern unit is defined in a more precise and repeatable way, but was chosen such that a candle's luminous intensity is still about one candela.
Temperature[edit source | editbeta]
See also: Combustion
The hottest part of the flame is just above the very dull blue part to one side of the flame, at the base. At this point, the flame is about 1,400 °C. However note that this part of the flame is very small and releases little heat energy. The blue color is due to chemiluminescence, while the visible yellow color is due to radiative emission from hot soot particles. The soot is formed through a series of complex chemical reactions, leading from the fuel molecule through molecular growth, until multi-carbon ring compounds are formed. The thermal structure of a flame is complex, hundreds of degrees over very short distances leading to extremely steep temperature gradients. On average, the flame temperature is about 1,000 °C.[7][citation needed] The color temperature is approximately 1,000 K.
Candle flame[edit source | editbeta]
Candle flame with zones marked
A candle flame has three distinct regions. The innermost zone, directly above the wick contains wax vapors that have just been vaporized. The middle zone, the yellow portion of the flame is an oxygen depleted zone, where partial oxidation has occurred, but insufficient oxygen exists to burn all of the vapors present. The temperature in this region is hotter than the innermost zone, but cooler than the outer zone. The outer zone is the area where the flame is the hottest and the oxidation process is complete.[8]
History of study[edit source | editbeta]
One of Michael Faraday's significant works was The Chemical History of a Candle, where he gives an in-depth analysis of the evolutionary development, workings and science of candles.[9] Hazards[edit source | editbeta]
According to the U.S. National Fire Protection Association, candles are one of the leading sources of residential fires in the U.S. with almost 10% of civilian injuries and 6% of civilian fatalities from fire attributed to candles.[10]
A candle flame that is longer than its laminar smoke point[11] will emit soot. Soot inhalation has known health hazards. Proper wick trimming will substantially reduce soot emissions from most candles.
The liquid wax is hot and can cause skin burns, but the amount and temperature are generally rather limited and the burns are seldom serious. The best way to avoid getting burned from splashed wax is to use a candle snuffer instead of blowing on the flame. A candle snuffer is usually a small metal cup on the end of a long handle. When placed over the flame the oxygen supply is cut off. They were used daily when the candle was the main source of lighting a home, before electric lights were available.
Glass candle holders are sometimes cracked by thermal shock from the candle flame, particularly when the candle burns down to the end. When burning candles in glass holders or jars, users should avoid lighting candles with chipped or cracked containers, and stop use once 1/2 inch or less of wax remains.
A former worry regarding the safety of candles was that a lead core was used in the wicks to keep them upright in container candles. Without a stiff core, the wicks of a container candle could sag and drown in the deep wax pool. Concerns rose that the lead in these wicks would vaporize during the burning process, releasing lead vapors — a known health and developmental hazard. Lead core wicks have not been common since the 1970s. Today, most metal-cored wicks use zinc or a zinc alloy, which has become the industry standard. Wicks made from specially treated paper and cotton are also available. Regulation[edit source | editbeta]
Candles and candle accessories pose a risk to property and people. Risk can be reduced by ensuring products comply with international standards.
Protecting consumers must be a priority for manufacturers, buyers, importers and retailers of candles and their accessories. International markets have developed a range of Standards and Regulations to ensure compliance, at the same time as maintaining and improving safety, including:
Europe: GPSD, EN 15493, EN 15494, EN 15426, EN 14059, REACH, RAL-GZ 041 Candles (Germany), French Decree 91-1175 USA: ASTM F2058, ASTM F2179, ASTM F2417, ASTM F2601, ASTM F2326, California Proposition 65, CONEG China: QB/T 2119 Basic Candle, QB/T 2902 Art Candle, QB/T 2903 Jar Candle, GB/T 22256 Jelly Candle[12] Accessories[edit source | editbeta]
Candle holders[edit source | editbeta]
A candle in a candle stick
Decorative candle holders, especially those shaped as a pedestal, are called candlesticks; if multiple candle tapers are held, the term candelabrum is also used. The root form of chandelier is from the word for candle, but now usually refers to an electric fixture. The word chandelier is sometimes now used to describe a hanging fixture designed to hold multiple tapers.
Many candle holders use a friction-tight socket to keep the candle upright. In this case, a candle that is slightly too wide will not fit in the holder, and a candle that is slightly too narrow will wobble. Candles that are too big can be trimmed to fit with a knife; candles that are too small can be fitted with aluminium foil. Traditionally, the candle and candle holders were made in the same place, so they were appropriately sized, but international trade has combined the modern candle with existing holders, which makes the ill-fitting candle more common. This friction tight socket is only needed for the federals and the tapers. For tea light candles, there are a variety of candle holders, including small glass holders and elaborate multi candle stands. The same is true for votives. Wall sconces are available for tea light and votive candles. For pillar type candles, the assortment of candle holders is broad. A fireproof plate, such as a glass plate or small mirror, is a candle holder for a pillar style candle. A pedestal of any kind, with the appropriate- sized fireproof top, is another option. A large glass bowl with a large flat bottom and tall mostly vertical curved sides is called a hurricane. The pillar style candle is placed at the bottom center of the hurricane. A hurricane on a pedestal is sometimes sold as a unit.
A bobèche is a drip-catching ring, which may also be affixed to a candle holder, or used independently of one. They can range from ornate metal or glass, to simple plastic, cardboard, or wax paper. Use of paper or plastic bobèches is common at events where candles are distributed to a crowd or audience, such as Christmas carols or other concerts/festivals.
Candle followers[edit source | editbeta]
These are glass or metal tubes with an internal stricture partway along, which sit around the top of a lit candle. As the candle burns, the wax melts and the follower holds the melted wax in, whilst the stricture rests on the topmost solid portion of wax. Candle followers are often deliberately heavy or 'weighted', to ensure they move down as the candle burns lower, maintaining a seal and preventing wax escape. The purpose of a candle follower is threefold:
To contain the melted wax - making the candle more efficient, avoiding mess, and producing a more even burn As a decoration - either due to the ornate nature of the device, or (in the case of a glass follower) through light dispersion or colouration And sometimes to shield the flame from wind.
Candle followers are often found in churches on altar candles.
Candle snuffers[edit source | editbeta]
Main article: Candle snuffer
Candle snuffers are instruments used to extinguish burning candles by smothering the flame with a small metal cup that is suspended from a long handle, and thus depriving it of oxygen. An older meaning refers to a scissor-like tool used to trim the wick of a candle. With skill, this could be done without extinguishing the flame. The instrument now known as a candle snuffer was formerly called an "extinguisher" or "douter". Etymology[edit source | editbeta]
The word candle comes from Middle English candel, from Old English and from Anglo-Norman candele, both from Latin candla, from candre, to shine.[13] History[edit source | editbeta]
Bees wax candles from the alemannic grave field of Oberflacht (de), Germany dating to 6th/7th century A.D. The oldest surviving bees wax candles north of the Alps. Main article: History of candle making
The earliest known candles originated in China around 200 BC, and were made from whale fat. Candles did not appear in Europe or the Middle East until sometime after AD 400, due largely to the availability of olive oil for burning in lamps.[14] The early European candle was made from various forms of natural fat, tallow, and wax. In the 18th century, spermaceti, oil produced by the sperm whale, was used to produce a superior candle.[15] Late in the 18th century, colza oil and rapeseed oil came into use as much cheaper substitutes.
"Until of late years, candles were solely manufactured from bees' wax, spermaceti, or tallow. The application of scientific chemical research...all the best candles are now made from the pure solid and crystallizable margaric and stearic acids. These are freed from the fluid oleic acid, and from glycerine, which exist in combination with them in ordinary tallow, as well as from other analogous substances, as from paraffin (a carbo-hygroneous substance resembling spermaceti, prepared from tar and peat), the stearic and margaric acid in the cocoa-nut oil and the palm oil, besides the old substance spermaceti, and wax both vegetable and animal." —Candles, -Eighth edition, Encyclopedia Britannica, 1853
Paraffin was first distilled in 1830, and revolutionized candle-making, as it was an inexpensive material which produced a high-quality, odorless candle that burned reasonably cleanly. The industry was devastated soon after, however, by the distillation of kerosene (confusingly also called paraffin oil or just paraffin). Recently resin based candles that are freestanding and transparent have been developed, with the claim that they burn longer than traditional paraffin candles. They are usually scented and oil based.
In the Middle Ages in Europe, tallow candles were the most common candle. By the 13th century, candle making had become a guild craft in England and France. The candle makers (chandlers) went from house to house making candles from the kitchen fats saved for that purpose, or made and sold their own candles from small candle shops.[16]
Timekeeping[edit source | editbeta]
Main article: Candle clock
An advent candle burning on the fourth day of December.
With the fairly consistent and measurable burning of a candle, a common use was to tell the time. The candle designed for this purpose might have time measurements, usually in hours, marked along the wax. The Song dynasty in China (960–1279) used candle-clocks.[17] By the 18th century, candle-clocks were being made with weights set into the sides of the candle. As the candle melted, the weights fell off and made a noise as they fell into a bowl. A form of candle-clock was used in coal-mining until the 20th century.[citation needed] In the days leading to Christmas some people burn a candle a set amount to represent each day, as marked on the candle. The type of candle used in this way is called the Advent candle,[18] although this term is also used to refer to a candle that decorates an Advent wreath. Use[edit source | editbeta]
Before the invention of electric lighting, candles and oil lamps were commonly used for illumination. In areas without electricity, they are still used routinely. Until the 20th century, candles were more common in northern Europe. In southern Europe and the Mediterranean, oil lamps predominated. In the developed world today, candles are used mainly for their aesthetic value and scent, particularly to set a soft, warm, or romantic ambiance, for emergency lighting during electrical power failures, and for religious or ritual purposes. Scented candles are used in aromatherapy.
Religion[edit source | editbeta]
Main article: Ceremonial use of lights#Candles
Candles are used in the religious ceremonies of many faiths.
History of Candles Candles have been used for light and to illuminate man's celebrations for more than 5,000 years, yet little is known about their origin.
It is often written that the first candles were developed by the Ancient Egyptians, who used rushlights or torches made by soaking the pithy core of reeds in melted animal fat. However, the rushlights had no wick like a true candle. Early Wicked Candles
The Egyptians were using wicked candles in 3,000 B.C., but the ancient Romans are generally credited with developing the wicked candle before that time by dipping rolled papyrus repeatedly in melted tallow or beeswax. The resulting candles were used to light their homes, to aid travelers at night, and in religious ceremonies.
Historians have found evidence that many other early civilizations developed wicked candles using waxes made from available plants and insects. Early Chinese candles are said to have been molded in paper tubes, using rolled rice paper for the wick, and wax from an indigenous insect that was combined with seeds. In Japan, candles were made of wax extracted from tree nuts, while in India, candle wax was made by boiling the fruit of the cinnamon tree.
It is also known that candles played an important role in early religious ceremonies. Hanukkah, the Jewish Festival of Lights which centers on the lighting of candles, dates back to 165 B.C. There are several Biblical references to candles, and the Emperor Constantine is reported to have called for the use of candles during an Easter service in the 4th century. Middle Ages
Most early Western cultures relied primarily on candles rendered from animal fat (tallow). A major improvement came in the Middle Ages, when beeswax candles were introduced in Europe. Unlike animal-based tallow, beeswax burned pure and cleanly, without producing a smoky flame. It also emitted a pleasant sweet smell rather than the foul, acrid odor of tallow. Beeswax candles were widely used for church ceremonies, but because they were expensive, few individuals other than the wealthy could afford to burn them in the home.
Tallow candles were the common household candle for Europeans, and by the 13th century, candlemaking had become a guild craft in England and France. The candlemakers (chandlers) went from house to house making candles from the kitchen fats saved for that purpose, or made and sold their own candles from small candle shops. Colonial Times
Colonial women offered America's first contribution to candlemaking, when they discovered that boiling the grayish- green berries of bayberry bushes produced a sweet-smelling wax that burned cleanly. However, extracting the wax from the bayberries was extremely tedious. As a result, the popularity of bayberry candles soon diminished.
The growth of the whaling industry in the late 18th century brought the first major change in candlemaking since the Middle Ages, when spermaceti -- a wax obtained by crystallizing sperm whale oil -- became available in quantity. Like beeswax, the spermaceti wax did not elicit a repugnant odor when burned, and produced a significantly brighter light. It also was harder than either tallow or beeswax, so it wouldn't soften or bend in the summer heat. Historians note that the first "standard candles" were made from spermaceti wax. 19th Century Advances
Most of the major developments impacting contemporary candlemaking occurred during the 19th century. In the 1820s, French chemist Michel Eugene Chevreul discovered how to extract stearic acid from animal fatty acids. This lead to the development of stearin wax, which was hard, durable and burned cleanly. Stearin candles remain popular in Europe today.
In 1834, inventor Joseph Morgan helped to further the modern-day candle industry by developing a machine that allowed for continuous production of molded candles by using a cylinder with a movable piston to eject candles as they solidified. With the introduction of mechanized production, candles became an easily affordable commodity for the masses.
Paraffin wax was introduced in the 1850s, after chemists learned how to efficiently separate the naturally-occurring waxy substance from petroleum and refine it. Odorless and bluish-white in color, paraffin was a boon to candlemaking because it burned cleanly, consistently and was more economical to produce than any other candle fuel. Its only disadvantage was a low melting point. This was soon overcome by adding the harder stearic acid, which had become widely available. With the introduction of the light bulb in 1879, candlemaking began to decline. The 20th Century
Candles enjoyed renewed popularity during the first half of the 20th century, when the growth of U.S. oil and meatpacking industries brought an increase in the byproducts that had become the basic ingredients of candles – paraffin and stearic acid.
The popularity of candles remained steady until the mid-1980s, when interest in candles as decorative items, mood-setters and gifts began to increase notably. Candles were suddenly available in a broad array of sizes, shapes and colors, and consumer interest in scented candles began to escalate.
The 1990s witnessed an unprecedented surge in the popularity of candles, and for the first time in more than a century, new types of candle waxes were being developed. In the U.S., agricultural chemists began to develop soybean wax, a softer and slower burning wax than paraffin. On the other side of the globe, efforts were underway to develop palm wax for use in candles. Today's Candles
Candles have come a long way since their initial use. Although no longer man's major source of light, they continue to grow in popularity and use. Today, candles symbolize celebration, mark romance, soothe the senses, define ceremony, and accent home decors — casting a warm and lovely glow for all to enjoy.
Wax usually refers to a substance that is a solid at ambient temperature and that, on being subjected to slightly higher temperatures, becomes a low viscosity liquid. The chemical composition of waxes is complex; all of the products have relatively wide molecular weight profiles, with the functionality ranging from products, which contain mainly normal alkanes to those, which are mixtures of hydrocarbons and reactive functional species.
For centuries, the honeycomb of bees, i.e., beeswax, was the material commonly referred to as wax. Substances having typical wax characteristics have traditionally come from insects, e.g., beeswax; from vegetables, e.g., carnauba. And from animal, e.g., spermaceti, origins (1). Waxes from mineral and synthetic Supplies have been developed both as substitutes for waxes from traditional Supplies and for new applications. Waxes from minerals and synthetic Supplies now surpass waxes from traditional Supplies in tonnage and commercial importance.
Waxes obtained from natural Supplies such as vegetables or insects are subject to weather conditions, which may severely affect the stability of supply and price and, to a lesser extent, the consistency of the products. Waxes from minerals and synthetic Supplies are less susceptible to weather conditions, and thus have a more stable supply and price.
Insect and Animal Waxes
Beeswax. White [8012-89-3J and yellow [8006-40-4J beeswax has been known for over 2000 years, especially through its use in the fine arts (2). References to wax prior to the nineteenth century are probably to beeswax. Beeswax is secreted by bees and is used to construct the combs in which bees store their honey. Removing the honey and melting the comb in boiling water harvest the wax; the melted product is then filtered and cast into cakes. The yellow beeswax cakes can be bleached with oxidizing agents to white beeswax, a product much favored in the cosmetic industry.
The composition of beeswax varies, depending on its geographic origin. The major components are esters of C30 and C32 alcohols with C16 acids, free C25 to C31 carboxylic acids, and C25 to C31 hydrocarbons (4). Beeswax typically has a melting point of 640C, a penetration (hardness) of 20 dmm at 250C and 76 dmm at 43.30C (ASTM D1321), a viscosity of 1470 mm2/s at 98.90C, an acid number of 20, and a saponification number of 84. The major use of beeswax is in the cosmetic industry, with smaller amounts used in pharmaceuticals and candle production.
Spermaceti. Spermaceti [8002-23-il is derived from the head oil of the perm whale. Owing to the present status of the sperm whale as an endangered species, however, the material is no longer an item of commerce and has been replaced by other natural and synthetic waxes.
Vegetable Waxes
Carnauba. The source of carnauba wax [8015-86-9] is the palm tree, whose wax-producing stands grow almost exclusively in the semiarid northeast section of Brazil. Carnauba wax forms on the fronds of the palm, and is removed by cutting the fronds, drying, and mechanically removing the wax. Impurities are removed from the wax by melting and filtering or centrifuging. Wide fluctuations in price and availability have caused markets served by carnauba wax to seek replacements. Whereas there is no other single wax, which combines all the properties of carnauba, suitable substitutes are available for most applications.
The major components of carnauba wax are aliphatic and aromatic esters of long-chain alcohols and acids, with smaller amounts of free fatty acids and alcohols, and resins. Carnauba wax is very hard, with a penetration of 2 dmm at 250C and only 3 dmm at 43.30C. Carnauba also has one of the higher melting points for the natural waxes at 840C, with a viscosity of 3960 mm2/s at 98.90C, an acid number of 8, and a saponification number of 80.
The hardness and high melting point, when combined with its ability to disperse pigments such as carbon black, allows Carnauba wax increasing use in the thermal printing inks. Carnauba is also widely used to gel organic solvents and oils, making the wax a valuable component of solvent and oil paste formulations. Carnauba polishes to a high gloss and thus is widely used as a polishing agent for items such as leather, candies, and pills. Other uses include cosmetics and investment casting applications (see COPPER ALLOYS, CAST COPPER ALLOYS).
Candelilla. Candelilla wax [8006-44-8j is harvested from shrubs in the Mexican states of Coahuila and Chihuahua and, to a very small degree, in the Big Bend region of Texas in the United States (6). The entire mature plant is uprooted and immersed in boiling water acidified with sulfuric acid. The wax floats to the surface and is filtered .The major components of Candelilla wax are hydrocarbons, esters of long-chain alcohols and acids, long-chain alcohols, sterols, and neutral resins, and long- chain acids. Typically, Candelilla wax has a melting point of 700C, a penetration of 3 dmm at 250C, an acid number of 14, and a saponification number of 55. Principal markets for Candelilla include cosmetics, foods, and pharmaceuticals
Japan Wax. Japan wax [8001-39-6] is a fat and is derived from the berries of a small tree native to Japan and China cultivated for its wax. Japan wax is composed of triglycerides, primarily tripalmitin. Japan wax typically has a melting point of 530C, an acid number of 18, and a saponification number of 217. Principal markets include the formulation of candles, polishes, lubricants, and as an additive to thermoplastic resins. The product has some food-related applications.
Ouricury Wax. Ouricury wax [68917-70-4] is a brown wax obtained from the fronds of a palm tree, which grows in Brazil. Ouricury is difficult to harvest, as it does not flake off the frond as does carnauba wax; rather, it must be scraped free. Ouricury is sometimes used as a replacement for carnauba in applications that do not require a light-colored wax.
Rice-Bran Wax. Rice-bran wax [8016-60-2] is extracted from crude rice-bran oil. It can be degummed, the fatty acid content reduced by solvent extraction, and bleached. The wax is primarily composed of esters of lignoceric acid ~43 wt %), behenic acid (16 wt %), and C22-C36 alcohols (28 wt %).
Jojoba. Jojoba oil [61789-91-1] is obtained from the seeds of the jojoba plant grown in semiarid regions of Costa Rica, Israel, Mexico, and the United States. The oil is made up of ca 80 wt % of esters of eicos- 1 1-enoic and docos- 13-enoic acids, and eicos-11-en-1-ol, and docos-13-en-1-ol, ca 17 wt % of other liquid esters, with the balance being free alcohols, free acids, and steroids. Jojoba oil is used primarily in the formulation of cosmetics. Hydrogenated jojoba oil is a wax used in candles and other low volume specialty applications.
Castor Wax. Castor wax [8001-78-31 is catalytically hydrogenated castor bean oil. The wax has a melting point of 860C, acid number of 2, saponification number of 179, and an iodine number of 4. Castor wax is used primarily in the formulation of cosmetics. Derivatives of castor wax are used as surfactants and plastics additives.
Bayberry Wax. Bayberry wax [8038-77-5] is removed from the surface of the berry of the bayberry (myrtle) shrub by boiling the berries in water and skimming the wax from the surface of the water. The wax is green and made up primarily of lauric, myristic, and palmitic acid esters. The wax has a melting point of 45~C, an acid number of 15, a saponification number of 220, and an iodine number of 6. The wax has an aromatic odor and is used primarily in the manufacture of candles and other products where the distinctive odor is desirable.
Mineral Waxes
Montan Wax. Montan wax [8002-53-7] is derived by solvent extraction of lignite (qv). The earliest production on a commercial scale was in Germany during the latter half of the nineteenth century, and Germany continues to supply the majority of the world‘s production of Montan wax. Montan wax production at Amsdorf is part of a massive coal-mining operation from a continuous vein and raw material is expected to last for decades. The composition of Montan wax depends on the material from which it is extracted, but all contain varying amounts of wax, resin, and asphalt. Black Montan wax may be further processed to remove the resins and asphalt, ~ is known as refined Montan wax. White Montan wax has been reacted with alcohols to form esters. The wax component of Montan is a mixture of long. chain (C24-C30) esters (62-68 wt %), long-chain acids (22-26 wt %), and long. chain alcohols, ketones, and hydrocarbons (7-15 wt %). Crude Montan wax fro~ Germany typically has a melting point of 800C, an acid number of 32, and a saponification number of 92.
The largest traditional use for Montan waxes was as a component in on~ time hot-melt carbon-paper inks. With the decrease in the use of carbon-paper inks, uses for the refined grades have become predominant, mainly in the formulation of polishes and as plastics lubricants.
Peat Waxes. Peat waxes are much like Montan waxes in that they contain three main components: a wax fraction, a resin fraction, and an asphalt fraction. The amount of asphalt in the total yield is influenced strongly by the solvent used in the extraction. Montan waxes contain ca 50 wt % more of the wax fraction than peat waxes, and correspondingly lower percentages of the resin and asphalt fractions. The wax fraction in peat wax is chemically similar to that of the wax fraction in Montan wax.
Ozokerite and Ceresin Waxes. Ozokerite wax [OO1-75-O] was a product of Poland, Austria, and in the former USSR where it was mined. True ozokerite no longer seems to be an article of commerce, and has been replaced with blends of petroleum-derived paraffin and microcrystalline waxes. These blends are designed to meet the specific physical properties required by the application involved.
Ceresin wax [8001-75-0] originally was a refined and bleached ozokerite wax, but now is a paraffin wax of very narrow molecular weight distribution or blend of petroleum waxes.
Petroleum Waxes. Waxes derived from petroleum are hydrocarbons of three types: paraffin [64742-43-4] (clay- treated); semi microcrystalline or intermediate; and microcrystalline [64742-42-31 (clay-treated). Semi microcrystalline waxes are not generally marketed as such (7). Others include acid-treated, chemically neutralized, and hydro treated; and paraffin and hydrocarbon waxes, untreated. The quality and quantity of the wax separated from the crude oil depends on the source of the crude oil and the degree of refining to which it has been subjected prior to wax separation. Petroleum waxes are produced in massive quantities throughout the world. Subject to the wax content in the crude, paraffin and, to a substantially lesser degree, microcrystalline waxes are produced in almost all countries of the world that refine crude oil.
A paraffin wax is a petroleum wax consisting principally of normal alkanes. Microcrystalline wax is a petroleum wax containing substantial proportions of branched and cyclic saturated hydrocarbons, in addition to normal alkanes. Semi microcrystalline wax contains more branched and cyclic compounds than paraffin wax, but less than microcrystalline. A classification system based on the refractive index of the wax and its congealing point as determined by ASTM D938 was developed (9).
Table 3. Typical Properties of Petroleum Waxes Wax Property Paraffin Microcrystalline Flash point, closed cup, C 204’ 260’ Viscosity at 98.90C, mm-9/s 4.2-7.4 10.2-25 Melting range, ~C 46-68 60-93 Refractive index at 98.9~C 1.430-1.433 1.435-1.445 Number average molecular weight 350-420 600-800 Carbon atoms per molecule 20-36 30-75 Ductility crystallinity of solid wax Friable to crystalline Ductile-plastic to tough-brittle Value is minimum.
Paraffin wax is macro crystalline, brittle, and is composed of 40-90 wt % normal alkanes, with the remainder C18-C36 isoalkanes and cycloalkanes. Paraffin wax has little affinity for oil content: fully refined paraffin has less than 1 wt %; crude scale, 1-2 wt %, and slack [64742-61-61, above 2 wt %. Within these classes, the melting point of the wax determines the actual grade, with a range of about 46-71‖C. Typical properties of petroleum waxes are listed in Table‗3.
The separation of paraffin wax from crude oil occurs during distillation, as shown in Figure 1. The distillate is processed to remove oil to the degree desired through solvent extraction. It is then decolorized, usually by hydrogenation, but percolation through bauxite is also used. Microcrystalline wax is produced either from the residual fraction of crude oil distillation or from crude oil tank bottoms 10). After deasphalting of the residual fraction, heavy lubricating oil is removed by solvent extraction. The degree of solvent extraction is dictated by the economics of the lubrication oil market. The filtrate is crude petrolatum, a dark-colored, unctuous material containing oil and microcrystalline wax. Percentages of each may vary, but are usually about 40 wt % wax and 60 wt % oil. This material is then solvent-extracted for the wax. Because microcrystalline wax has great affinity for oil, the oil content of the wax is 1-4 wt %, depending on the grade of the wax. Unlike paraffin wax, oil is held tightly in the crystal lattice of the microcrystalline wax, and does not migrate to the surface. The microcrystalline waxes obtained from petrolatums are generally known as plastic grades, with penetrations greater than 11 dmm at 25‘C.
Crude oil contains high molecular weight fractions, which are soluble at the high temperatures found in underground formations, but not very soluble at ambient conditions once the crude oil is produced. These high molecular weight fractions precipitate onto the walls and floors of storage tanks, and are known as crude oil tank bottoms. Crude oil tank bottoms are essentially crude Oil with very high wax contents and are processed as indicated in Figure 1. The microcrystalline waxes obtained from crude oil tank bottoms are generally known as hard grades, with penetrations less than 11 dmm at 250C.
The Bundesges undheitsamt (BGA) of Germany also has specifications for refined petroleum waxes used in food applications. Many other countries reference either the FDA or BGA specifications for their food regulations. Petroleum wax is widely used in chewing gum to modify the properties of the chewing gum base. The wide range of properties available help chewing gum base manufacturers formulate a broad variety of chewing gum, ranging from the traditional hard stick gum to the softer bubble gum. Petroleum wax can also be used as protective coatings for fruits, vegetables, and cheeses. Petroleum wax is outstanding as a cost-effective moisture and gas barrier, and food- packaging applications are a major market for refined food-grade petroleum wax. Blends of paraffin and microcrystalline wax are used by themselves or in combination with other additives such as high molecular weight polyethylene and ethylene vinyl acetate copolymers to improve the performance of paper packaging such as paperboard boxes, paper containers, and flexible packaging.
Petroleum waxes are also widely used in other industrial applications. Paraffin waxes are added to rubber during compounding, and exude to the surface during curing, which helps protect the rubber from degradation resulting from ozone. Paraffin and other waxes can be added to plastics, especially poly (vinyl chloride) (PVC) as lubricants. Both paraffin and microcrystalline waxes are widely used to help control the properties of hot-melt adhesives. Dispersions of microcrystalline are added to ink to improve slip and rub properties. Petroleum waxes are used in many consumer applications such is cosmetics, polishes, and candles. Unrefined petroleum waxes are often used n fireplace logs.
Synthetic Waxes
Polyethylene Waxes. Low molecular weight (less than ca 10,000 Mn) polyethylenes [9002-88-41 having wax like properties are made either by high-pressure polymerization or low-pressure (Zeigler-type catalysts) polymerization. All the products have the same basic structure, but the processes yield products h distinctly different properties. Some polyethylenes have fairly low density owing to branching that occurs during the polymerization. Molecular weight distributions, expressed as the weight average molecular weight divided by the number average molecular weight, or polydispersity, also varies widely among the different processes, as does the range of molecular weights available.
Differences among the processes have a major impact on the use of the products. Products from a particular process or manufacturer may dominate one market, while products from a different process may be preferred in a different application. Major uses include hot-melt adhesives for applications requiring high temperature performance, additives to improve the processing of plastics, slip and rub additives for inks and paints, and cosmetic applications.
Products used in food applications require regulatory approvals. This regulation includes a maximum amount of hexane-soluble material with other requirements. The amount of material extracted by hexane is a function of molecular weight and branching. The FDA under the synthetic petroleum wax regulation, 21 CFR 172.888, regulates polyethylenes in the 500-1200-molecular weight range. In addition to molecular weight requirements, this regulation includes an absorbance test to verify the suitability of the product for food applications.
Some by-product polyethylene waxes have been recently introduced. The feedstock for these materials is mixtures of low molecular weight polyethylene fractions and solvent, generally hexane, produced in making polyethylene plastic resin. The solvent is stripped from the mixture, and the residual material offered as polyethylene wax. The products generally have a wider molecular weight distribution than the polyethylene waxes synthesized directly, and are offered to markets able to tolerate that characteristic. Some of the by-product polyethylene waxes are distilled under vacuum to obtain a narrower molecular weight distribution.
Several of the polymerization processes allow different functionality to be added to the backbone of the polymer, including copolymers of ethene, propene, hexene, vinyl acetate, and acrylic acid, with warlike properties. Copolymers of ethene with other olefins provide a method of extending the range of properties available. The addition of other olefins creates a branched polymer, which decreases the melting point and hardness, while increasing viscosity as compared to a linear polyethylene of the same molecular weight distribution. Longer branches created through the addition of hexene show a larger effect than those from propene. Copolymers with vinyl acetate and acrylic acid provide a method of introducing oxygen functionality. These products may be further reacted with metal salts to form ionomers.
In addition to co polymerization, polyethylene's terminated as ketones. Alcohols, and carboxylic acids with molecular weights as high as 700 Daltons are now available. The products offer the same chemical functionality as common fatty alcohols and acids, but are higher melting and harder. Similar to the fatty alcohols and acids, derivatives such as ethoxylates, esters, and amides also are available as higher melting versions of the fatty derivatives.
Functional polyethylene waxes provide both the physical properties obtained by the high molecular weight polyethylene wax and the chemical properties of an oxidized product, and one derived from a fatty alcohol or acid. The functional groups improve adhesion to polar substrates, compatibility with polar materials, and dispersibility into water. Uses include additives for inks and coatings, pigment dispersions, plastics, cosmetics, toners, and adhesives.
Fischer-Tropsch Waxes. Polyethylene wax [8OO2-74-2] production is based on the Fischer-Tropsch synthesis, which is basically the polymerization of carbon monoxide under high pressure and over special catalysts to produce hydrocarbons (see FUELS, SYNTHETIC-LIQUID FUELS). Distillation is then used to separate the hydrocarbons into different products, including liquid fuels and waxes with melting points ranging from about 45-1060C. Currently the waxes are produced in large volumes in South Africa and Malaysia, with an estimated 12,000-14,000 t consumed in the United States in 1994. Uses are similar to those for polyethylene waxes, including hot-melt adhesives and additives for inks and coatings.
Chemically Modified Waxes. Hydrocarbon waxes of the microcrystalline, polyethylene, and polyethylene classes are chemically modified to meet specific market needs. In the vast majority of cases, the first step is air oxidation of the wax with or without catalysts (11). The product has an acid number usually no higher than 30 and a saponification number usually no lower than 25. An alternative step is the reaction of the wax with a polycarboxylic acid, e.g., maleic, at high temperature (12). Through its carboxyl groups, the oxidized wax can be further modified in such reactions as saponification or esterification. Oxidized wax is easily emulsified in water through the use of surfactants or simple soaps, and is widely used in many coating and polish applications.
Substituted Amide Waxes. The product of fatty acid amidation has unique wax like properties (13). Probably the most widely produced material is N,N‘distearylethylenediamine [110-30-5], which has a melting point of ca 140‘C, an acid number of ca 7, and a low melt viscosity. Because of its unusually high melting point and unique functionality, it is used in additive quantities to raise the apparent melting point of thermoplastic resins and asphalts, as an internal-external lubricant in the compounding of a variety of thermoplastic resins, and as a processing aid for elastomers.
Polymerized a-Olefins. Some polymers of higher a-olefins, e.g., C>20, have wax like properties and are sold as synthetic waxes. The polymerization process yields highly branched materials, with broad molecular weight distributions. Properties of the individual products are highly dependent on the a-olefin monomers and polymerization conditions. Melting points for the products range from 540C to 740C, with number average molecular weights ca 2600-2800, and penetrations at 250C of 5-12 dmm. The unique structure makes these products very effective when used in additive amounts to modify the properties of paraffin wax, primarily for use in candles. The products can increase the hardness and opacity of the paraffin, without increasing the cloud point or viscosity. Other uses include mold release for polyurethane foams, additives for casting wax, and additives for leather treating.
Analytical Techniques
Most waxes are complex mixtures of molecules with different carbon lengths, structures, and functionality. Attempts to measure the exact chemical composition are extremely difficult, even for the vegetable waxes, which are based on a relatively few number of basic molecules. Products such as oxidized microcrystalline wax not only have a mixture of hydrocarbon lengths and types as starting materials, but also add complexity through the introduction of various types of carboxylic functionality onto those hydrocarbons during the oxidation process.
Because of the difficulty in analysis of chemical composition, most of the routine test procedures on waxes are for the measurement of the physical proper-ties of the waxes and are used to compare the properties of waxes within a class. Some properties, such as acid number or saponification number, give insight into the chemical functionality of the product, and are widely used for products, which contain carboxyl groups such as vegetable, Montan, and oxidized waxes. Increasingly, instrumental methods such as gas chromatography (GC), gel permeation (also known as size exclusion) chromatography (GPC), refractive index (RI), differential scanning calorimetry (DSC), infrared spectroscopy (IR), and nuclear magnetic resonance (NMR) are being used to further characterize the products. Properties such as molecular weight distribution, degree of branching, degree of crystallinity, and functionality can be readily measured with these techniques.
Melting and Congealing Points. Selection of the proper melting point method depends upon the characteristics of the wax. Drop melting point (ASTM D127) is suitable for amorphous waxes, e.g., microcrystallines, but is not reliable for higher viscosity synthetic waxes, for which ring-and-ball softening point (ASTM D36) should be used. ASTM D87 may evaluate waxes whose time-temperature cooling curves exhibit plateaus, e.g., paraffin wax. Open or closed capillary tubes are used to measure the melting point of many of the natural waxes. The congealing point (ASTM D938) is the temperature at which a melted wax ceases to flow, and is more consistent than melting points for some waxes.
Hardness (Penetration). The standard test for the hardness of waxes in industry is the penetration test (ASTM D1321). This test measures the depth in tenths of a millimeter that a needle of a certain configuration under a given weight penetrates the surface of a wax at a given temperature. A series of penetrations measured at different temperatures, rather than at a single temperature, is preferred.
Color. On solidification of a wax and depending on factors such as the rate of cooling, the amount of occluded air, and surface finish, the color of solidified samples of the same wax may be different. For this reason, the color of most waxes is judged only while molten, although some commercial standards for certain waxes, e.g., carnauba, are based on the color of the solid wax. The accurate measurement of color in light-colored, i.e., amber to off-white to white, waxes is difficult but very important because of the additional processing costs required to achieve the light color. The two most widely used color standards providing numerical measurement are ASTM D1500, which is used to measure dark-brown to off-white color, and ASTM D156, which is used to measure off- white to pure white.
Oil content. The production of petroleum waxes involves the removal of oil; therefore, the oil content (actually the percentage of oil and low molecular weight fractions) is one indication of the quality of the wax. Oil content is determined (ASTM D721) as that percentage of the wax soluble in methyl ethyl ketone at -31.7 degrees C.
Viscosity. Although traditionally of little importance in the evaluation of vegetable and insect waxes, viscosity is an important test for mineral and synthetic waxes. One of the most frequently used tests, ASTM D88, is used to measure the time in seconds required for a specified quantity of wax at a specified temperature to flow by gravity through an orifice of specified dimensions. This viscosity is expressed in Saybolt Universal Seconds (SUS) at the temperature of the test. The SI unit for kinematic viscosity is mm2/s (=cSt).
Acid Number. The acid number (ASTM D1386) is the milligrams of potassium hydroxide necessary to neutralize one gram of wax, and indicates the amount of free carboxylic acid present. The test is widely used for vegetable and insect waxes, and synthetic waxes containing carboxylic acid groups.
Saponification Number. The saponification number (ASTM D1387) is the milligrams of potassium hydroxide, which react with one gram of wax under elevated temperatures, and indicates the amount of free carboxylic acid plus any ester materials, which may be saponified. Both the acid number and saponification numbers are generally provided to give an indication of the free carboxylic acid and ester content of vegetable and insect waxes, and synthetic waxes containing carboxylic acids and or esters.
Differential Scanning Calorimetry (DSC). The dsc has become widely used to characterize waxes. Under controlled heating and cooling rates, the amount of energy consumed or released is measured. Curves of heat flow v/s temperature provide insight into the thermal characteristics of a wax, including crystalline transitions such as solid-to-solid, solid-to-liquid, and liquid-to-solid. Common values obtained from the curves include the initial and ending temperatures for heat flow, and heat of fusion, expressed as joules per gram.
Gas Chromatography (GC). Gas chromatography has been used for many years, especially on the relatively simple structures of vegetable and insect waxes. Use of the GC for petroleum and synthetic waxes was limited by the maximum carbon number which could be eluted, and the number of isomers for each carbon number. Improvements in technology have allowed wider use of this technique, with columns and equipment available, which can resolve carbon numbers up to C100. Good resolution can be obtained on products with generally only one type of structure, e.g., paraffins with a high preponderance of primary alkanes. Products such as microcrystalline wax, which contain several different branched isomers for each carbon number, plus some cyclic compounds, cannot be completely resolved, although useful information can still be obtained.
Gel Permeation Chromatography (GPC). The gpc (also known as size exclusion chromatography) is widely used to measure the molecular weight distribution for synthetic polyethylene waxes. Whereas gpc cannot match the resolution available in GC techniques, useful information regarding the molecular weight, and molecular weight distribution can be obtained for products with molecular weights too high for gas chromatography. The molecular weight is normally reported using the number average, Mn, or the weight average, Mw The ratio of the weight average to the number average is known as the polydispersity.Pd.
Infrared Spectroscopy (Ir). Infrared curves are used to identify the chemical functionality of waxes. Petroleum waxes with only hydrocarbon functionality show slight differences based on crystallinity, while vegetable and insect waxes contain hydrocarbons, carboxylic acids, alcohols, and esters. The ir curves are typically used in combination with other analytical methods such as DSC or gc/gpc to characterize waxes.
Nuclear Magnetic Resonance (NMR). The NMR analysis has been used in the polymer industry to measure properties such as amount and type of branching, polymerized ethylene oxide content, and hydroxyl content. The same techniques are applicable to waxes, and are used for both characterization and quality control.
Kerosene From Wikipedia, the free encyclopedia
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For other uses, see Kerosene (disambiguation).
An Australian kerosene bottle, containing blue-dyed kerosene.
Kerosene is a combustible hydrocarbon liquid. The name is derived from Greek: κηρός (keros) meaning wax. The word "Kerosene" was registered as a trademark by Abraham Gesner in 1854, and for several years, only the North American Gas Light Company and the Downer Company (to which Gesner had granted the right) were allowed to call their lamp oil "Kerosene" in the United States.[1] It eventually became a genericized trademark. It is sometimes spelled kerosine in scientific and industrial usage.[2] The term "kerosene" is usual in much of Canada, the United States, Australia and New Zealand.[3][4]
Kerosene is usually called paraffin in the UK, Ireland, Southeast Asia and South Africa. A more viscous paraffin oil is used as a laxative. A waxy solid extracted from petroleum is called paraffin wax. Kerosene is widely used to power jet engines of aircraft (jet fuel) and some rocket engines, but is also commonly used as a cooking and lighting fuel and for fire toys such as poi. In parts of Asia, where the price of kerosene is subsidized, it fuels outboard motors on small fishing boats.[5]
Kerosene lamps are widely used for lighting in rural areas of Asia and Africa where electrical distribution is not available or too costly for widespread use. Total kerosene consumption is equivalent to about 1.2 million barrels per day.[6]
Kerosene in some jurisdictions such as the U.S. is legally required[citation needed] to be stored in a blue container to avoid it being confused with the much more flammable gasoline, which is typically kept in a red container. In other jurisdictions, like many in Europe, there are no specific requirements for the storage of kerosene other than the container has to be closed and marked with its contents. Properties[edit source | editbeta]
Kerosene, a thin, clear liquid formed from hydrocarbons, with a density of 0.78–0.81 g/cm3, is obtained from the fractional distillation of petroleum between 150 °C and 275 °C, resulting in a mixture of carbon chains that typically contain between 6 and 16 carbon atoms per molecule.[7]
Regardless of the crude oil source or processing history, the major components of all kerosenes are branched and straight chain paraffins and naphthenes (cycloparaffins), which normally account for at least 70% by volume. Aromatic hydrocarbons in this boiling range, such as alkylbenzenes (single ring) and alkylnaphthalenes (double ring) do not normally exceed 25% by volume of kerosene streams. Olefins are usually not present at more than 5% by volume.[8]
The flash point of kerosene is between 37 and 65 °C (100 and 150 °F), and its autoignition temperature is 220 °C (428 °F).[9] The pour point of kerosene depends on grade, with commercial aviation fuel standardized at −47 °C (−53 °F).
Heat of combustion of kerosene is similar to that of diesel; its lower heating value is 43.1 MJ/kg (around 18,500 Btu/lb), and its higher heating value is 46.2 MJ/kg.[10]
Kerosene is immiscible in water (cold or hot), but miscible in petroleum solvents.
In the United Kingdom, two grades of heating oil are defined. BS2869 Class C1 is the lightest grade used for lanterns, camping stoves, wick heaters, and mixed with gasoline in some vintage combustion engines. BS2869 Class C2 is a heavier distillate, which is used as domestic heating oil. Premium kerosene is usually sold in 5 or 20 liter containers from hardware, camping and garden stores and is often dyed purple. Standard kerosene is usually dispensed in bulk by a tanker and is undyed.
National and international standards define the properties of several grades of kerosene used for jet fuel. Flash point and freezing point properties are of particular interest for operation and safety; the standards also define additives for control of static electricity and other purposes. History[edit source | editbeta]
Persian scholar Rāzi (or Rhazes) was the first to distill kerosene in the 9th century.
Abraham Gesner first distilled kerosene from bituminous coal and oil shale experimentally in 1846. Commercial production was achieved in 1854.
A queue for kerosene. Moscow, Russia, 1920s See also: coal oil
The process of distilling crude oil/petroleum into kerosene, as well as other hydrocarbon compounds, was first written about in the 9th century by the Persian scholar Rāzi (or Rhazes). In his Kitab al-Asrar (Book of Secrets), the physician and chemist Razi described two methods for the production of kerosene, termed naft abyad ("white naphtha"), using an apparatus called an alembic. One method involved using clay as an absorbent, whereas the other method involved using ammonium chloride (sal ammoniac).
The distillation process was to be repeated until the final product was perfectly clear and "safe to light", i.e. volatile hydrocarbon fractions had been mostly removed. Kerosene was also produced during the same period from oil shale and bitumen by heating the rock to extract the oil, which was then distilled.[11]
In 1846, Canadian geologist Abraham Gesner gave a public demonstration in Charlottetown, Prince Edward Island of a new process he had discovered. He heated coal in a retort and distilled from it a clear, thin fluid which he showed made an excellent lamp fuel. He coined the name "Kerosene" for his fuel, a contraction of keroselaion, meaning wax-oil.[12] The cost of extracting kerosene from coal was high.
Fortunately, Gesner recalled from his extensive knowledge of New Brunswick's geology a naturally occurring asphaltum called albertite. He was blocked from using it by the New Brunswick coal conglomerate because they had coal extraction rights for the province, and he lost a court case when their experts claimed albertite was a form of coal.[13] Gesner subsequently moved to Newtown Creek, Long Island, New York, in 1854, where he secured the backing of a group of businessmen. They formed the North American Gas Light Company, to which he assigned his patents.
Despite clear priority of discovery, Gesner did not obtain his first kerosene patent until 1854, two years after James Young's US patent. Gesner's method of purifying the distillation products appears to have been superior to Young's, resulting in a cleaner and better-smelling fuel. Manufacture of kerosene under the Gesner patents began in New York in 1854 and later in Boston, being distilled from bituminous coal and oil shale.[12]
In 1848, Scottish chemist James Young experimented with oil discovered seeping in a coal mine as a source of lubricating oil and illuminating fuel. When the seep became exhausted, he experimented with the dry distillation of coal, especially the resinous "boghead coal" (torbanite).
He extracted a number of useful liquids from it, one of which he named "paraffine oil", because at low temperatures, it congealed into a substance resembling paraffin wax. Young took out a patent on his process and the resulting products in 1850, and built the first truly commercial oil-works in the world at Bathgate in 1851, using oil extracted from locally mined torbanite, shale, and bituminous coal. In 1852, he took out a US patent for the same invention. These patents were subsequently upheld in both countries in a series of lawsuits, and other producers were obliged to pay him royalties.[12]
In 1851, Samuel Martin Kier began selling kerosene to local miners, under the name "Carbon Oil". He distilled this by a process of his own invention from crude oil. He also invented a new lamp to burn his product.[14] He has been dubbed the Grandfather of the American Oil Industry by historians.[15] Since the 1840s, Kier's salt wells were becoming fouled with petroleum. At first, Kier simply dumped the useless oil into the nearby Pennsylvania Main Line Canal, but later he began experimenting with several distillates of the crude oil, along with a chemist from eastern Pennsylvania.[16]
Ignacy Łukasiewicz, a Polish pharmacist residing in Lwów, had been experimenting with different kerosene distillation techniques, trying to improve on Gesner's process, using local seep oil. Many people knew of his work, but paid little attention to it. On the night of July 31, 1853, doctors at the local hospital needed to perform an emergency operation, virtually impossible by candlelight. They therefore sent a messenger for Łukasiewicz and his new lamps. The lamp burned so brightly and cleanly that the hospital officials ordered several lamps plus a large supply of fuel. Łukasiewicz realized the potential of his work and quit the pharmacy to find a business partner, and then travelled to Vienna to register his technique with the government. Łukasiewicz moved to the Gorlice region of Poland in 1854, and sank several wells across southern Poland over the following decade, setting up a refinery near Jasło in 1859.[17]
The widespread availability of cheaper kerosene was the principal factor in the precipitous decline in the whaling industry in the mid-to-late 19th century, as the leading product of whaling was oil for lamps. Fuel uses[edit source | editbeta]
Heating and lighting[edit source | editbeta]
Fuels for heating
Heating oil Wood pellet Kerosene Propane Natural gas Wood Coal
At one time, the fuel was widely used in kerosene lamps and lanterns. 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."[18] This may have been due to the common practice of adulterating kerosene with cheaper but more volatile hydrocarbon mixtures, such as naphtha.[19] Kerosene was a significant fire risk; in 1880, nearly two of every five New York City fires were caused by defective kerosene lamps.[20]
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.
A truck delivering kerosene in Japan
Kerosene is widely used in Japan as a home heating fuel for portable and installed kerosene heaters. In Japan, kerosene can be readily bought at any filling station or be delivered to homes.[citation needed]
In the United Kingdom and Ireland, kerosene is often used as a heating fuel in areas not connected to a gas pipeline network. It is used less for cooking where LPG is preferred owing to its (LPG's) easier lighting. Kerosene is still often the fuel of choice for range cookers such as Rayburn.
The Amish, who abstain from the use of electricity, rely on kerosene for lighting at night.
More ubiquitous in the late 19th and early 20th centuries, kerosene space heaters were often built into kitchen ranges, and kept many farm and fishing families warm and dry through the winter. At one time, citrus growers used a smudge pot fueled by kerosene to create a pall of thick smoke over a grove in an effort to prevent freezing temperatures from damaging crops. "Salamanders" are kerosene space heaters used on construction sites to dry out building materials and to warm workers. Before the days of electrically lighted road barriers, highway construction zones were marked at night by kerosene fired, pot-bellied torches. Most of these uses of kerosene created thick black smoke because of the low temperature of combustion.
A notable exception, discovered in the early 19th century, is the use of a gas mantle mounted above the wick on a kerosene lamp. Looking like a delicate woven bag above the woven cotton wick, the mantle is a residue of mineral materials (mostly thorium dioxide) which is heated to incandescence by the flame produced by the wick. The thorium and cerium oxide combination produces both a whiter light and a greater fraction of the energy in the form of visible light than a black body at the same temperature would. These types of lamps are still in use today in areas of the world without electricity, because they give a much better light than a simple wick-type lamp does.[citation needed]. Recently a multipurpose lantern which also doubles as cooking stove has been introduced in India in areas which do not have electricity.[21]
Transportation[edit source | editbeta]
In the mid-20th century, kerosene or tractor vaporising oil (TVO) was used as a cheap fuel for tractors. The engine would start on gasoline, then switch over to kerosene once the engine warmed up. 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.
In Europe following the Second World War, automobiles were modified similarly to run on kerosene rather than gasoline, which would have to be imported and was heavily taxed. Besides additional piping and the switch between fuels, the head gasket was replaced by a much thicker one to diminish the compression ratio (making the engine less powerful and less efficient, but able to run on kerosene). The necessary equipment was sold under the trademark "Econom".[22]
During the fuel crisis of the 1970s, Saab-Valmet developed and series-produced the Saab 99 Petro that ran on kerosene, turpentine or gasoline. The project, codenamed "Project Lapponia", was headed by Simo Vuorio, and towards the end of the 1970s, a working prototype was produced based on the Saab 99 GL. The car was designed to run on two fuels. Gasoline was used for cold starts and when extra power was needed, but normally it ran on kerosene or turpentine. The idea was that the gasoline could be made from peat using the Fischer–Tropsch process. Between 1980 and 1984, 3756 Saab 99 Petros and 2385 Talbot Horizons (a version of the Chrysler Horizon that integrated many Saab components) were made. One reason to manufacture kerosene-fueled cars was that in Finland kerosene was less heavily taxed than petrol.[23]
Kerosene is used to fuel smaller-horsepower outboard motors built by Yamaha Motors, Suzuki Marine, 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. Multiple fuel Evinrude and Mercury Racing engines also burn kerosene, as well as jet fuel.[24]
Today, kerosene is mainly used in fuel for jet engines in several grades. One form of the fuel known as RP-1 is 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):
37 C12H26(l) + /2 O2(g) → 12 CO2(g) + 13 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.[25] 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.[25]
Kerosene is sometimes used as an additive in diesel fuel to prevent gelling or waxing in cold temperatures.[26]
Ultra-low sulfur kerosene is a custom-blended fuel used by the New York City Transit to power its bus fleet. The transit agency started using this fuel in 2004, prior to the widespread adoption of ultra-low sulfur diesel, which has since become the standard. In 2008, the suppliers of the custom fuel failed to tender for a renewal of the transit agency's contract, leading to a negotiated contract at a significantly increased cost.[27]
Advert for an oil stove, from the Albion Lamp Company, Birmingham, England, c. 1900
In countries such as India and Nigeria,[28] kerosene is the main fuel used for cooking, especially by the poor, and kerosene stoves have replaced traditional wood-based cooking appliances. As such, increase in the price of kerosene can have a major political and environmental consequence. The Indian government subsidizes the fuel to keep the price very low, to around 15 US cents per liter as of February 2007, as lower prices discourage dismantling of forests for cooking fuel.[29] In Nigeria an attempt by the government to remove fuel subsidy which includes kerosene was met with strong opposition from the Nigeria populace.[30]
Kerosene is used as a fuel in portable stoves, especially in Primus stoves invented in 1892. Portable kerosene stoves earn a reputation of reliable and durable stove in everyday use, and perform especially well under adverse conditions. In outdoor activities and mountaineering, a decisive advantage of pressurized kerosene stoves over gas cartridge stoves is their particularly high thermal output and their ability to operate at very low temperature in winter or at high altitude.
Entertainment[edit source | editbeta]
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 odor, which becomes poisonous in sufficient concentration. Methanol was sometimes used instead, but the flames it produces look less impressive, and its lower flash point poses a high risk. Moreover, the catabolic products of methanol are highly toxic for the optic nerves, and can cause blindness when small amounts of methanol are swallowed. Swallowing larger amounts of methanol is lethal. Other uses[edit source | editbeta]
Insecticide[edit source | editbeta]
Kerosene has been found to be an effective pesticide. It is effective at killing a large number of insects, notably bed bugs and head lice. It can also be applied to standing pools of water in order to kill mosquito larvae.
Industrial[edit source | editbeta]
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).[31]
In the petroleum industry, kerosene is often used as a synthetic hydrocarbon for corrosion experiments to simulate crude oil in field conditions.
Medical[edit source | editbeta]
In X-ray crystallography, kerosene can be used to store crystals. When a hydrated crystal is left in air, dehydration may occur slowly. This makes the colour of the crystal become dull. Kerosene can keep air from the crystal.
Miscellanea[edit source | editbeta]
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).[32]
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.[32] It can be used to clean bicycle and motorcycle chains of old lubricant before relubrication.[32] Toxicity[edit source | editbeta]
Ingestion of kerosene is harmful or fatal. Kerosene should never be used to get rid of hair lice as it can cause burns and serious illness. A kerosene shampoo can even be fatal if fumes are inhaled.[33][34]