Phan Thị Kim Phúc (Vietnamese pronunciation: [faːŋ tʰɪ̂ˀ kim fúk͡p̚]; born April 6, 1963), referred to informally as the Napalm girl, is a South Vietnamese-born Canadian woman best known as the nine-year-old child depicted in the Pulitzer Prize-winning photograph taken at Trảng Bàng during the Vietnam War on June 8, 1972. The well-known photo, by AP photographer Nick Ut, shows her at nine years of age running naked on a road after being severely burned on her back by a South Vietnamese napalm attack.
Background
Phan Thi Kim Phúc and her family were residents of the village of Trảng Bàng in South Vietnam. On June 8, 1972, South Vietnamese planes dropped a napalm bomb on Trảng Bàng, which had been attacked and occupied by North Vietnamese forces. Kim Phúc joined a group of civilians and South Vietnamese soldiers who were fleeing from the Caodai Temple to the safety of South Vietnamese-held positions. The Republic of Vietnam Air Force
pilot mistook the group for enemy soldiers and diverted to attack. The
bombing killed two of Kim Phúc's cousins and two other villagers. Kim
Phúc received third degree burns after her clothing was burned by the
fire. Associated Press photographer Nick Ut's
photograph of Kim Phúc running naked amid other fleeing villagers,
South Vietnamese soldiers and press photographers became one of the most
haunting images of the Vietnam War. In an interview many years later, she recalled she was yelling, Nóng quá, nóng quá ("too hot, too hot") in the picture. The New York Times
editors were at first hesitant to consider the photo for publication
because of the nudity, but eventually approved it. A cropped version of
the photo—with the press photographers to the right removed—was featured
on the front page of The New York Times the next day. It later earned a Pulitzer Prize and was chosen as the World Press Photo of the Year for 1973.
After snapping the photograph, Ut took Kim Phúc and the other injured children to Barsky Hospital in Saigon, where it was determined that her burns were so severe that she probably would not survive. After a 14-month hospital stay and 17 surgical procedures including skin transplantations, she was able to return home. A number of the early operations were performed by Finnishplastic surgeon Aarne Rintala. It was only after treatment at a renowned special clinic in Ludwigshafen, West Germany, in 1982, that Kim Phúc was able to properly move again.
Ut continued to visit Kim Phúc until he was evacuated during the fall of Saigon, and they now speak almost weekly via telephone.
Thumbnails of the film footage showing the events just before and after the photograph was taken
Audio tapes of President Richard Nixon, in conversation with his chief of staff, H. R. Haldeman in 1972, reveal that Nixon mused, "I'm wondering if that was fixed", after seeing the photograph.
After the release of this tape, Ut commented, "Even though it has
become one of the most memorable images of the twentieth century,
President Nixon once doubted the authenticity of my photograph when he
saw it in the papers on 12 June 1972... The picture for me and
unquestionably for many others could not have been more real. The photo
was as authentic as the Vietnam War itself. The horror of the Vietnam
War recorded by me did not have to be fixed. That terrified little girl
is still alive today and has become an eloquent testimony to the
authenticity of that photo. That moment thirty years ago will be one Kim
Phúc and I will never forget. It has ultimately changed both our
lives."
Less publicized is the film shot by British television cameraman Alan Downes for the British ITN news service and his Vietnamese counterpart Le Phuc Dinhm who was working for the American television network NBC, which shows the events just before and after the photograph was taken
(see image on right). In the top-left frame, a man stands and appears
to take photographs as a passing airplane drops bombs. A group of
children, Kim Phúc among them, run away in fear. After a few seconds,
she encounters the reporters dressed in military fatigues, including Christopher Wain who gave her water (top-right frame) and poured some over her burns.
As she turns sideways, the severity of the burns on her arm and back
can be seen (bottom-left frame). A crying woman, Kim Phúc's grandmother,
Tao, runs in the opposite direction holding her badly burned
grandchild, 3-year-old Danh, Kim Phúc's cousin, who died of his injuries
(bottom-right frame). Sections of the film shot were included in Hearts and Minds (1974), the Academy Award-winning documentary about the Vietnam War directed by Peter Davis.
Adult life
Forgiveness
made me free from hatred. I still have many scars on my body and severe
pain most days but my heart is cleansed. Napalm is very powerful, but
faith, forgiveness, and love are much more powerful. We would not have
war at all if everyone could learn how to live with true love, hope, and
forgiveness. If that little girl in the picture can do it, ask
yourself: Can you?
Phúc was removed from her university as a young adult studying
medicine and used as a propaganda symbol by the communist government of
Vietnam. Due to constant pain she considered suicide but in 1982 she found a New Testament in a library that lead her to become a Christian. Her faith enabled her to forgive. In 1986, she was granted permission to continue her studies in Cuba. Prime Minister of Vietnam Phạm Văn Đồng
became her friend and patron. After arriving in Cuba, she met Bui Huy
Toan, another Vietnamese student and her future fiancé. In 1992, Phúc
and Toan married. On the way to their honeymoon in Moscow, they left the
plane during a refuelling stop in Gander, Newfoundland, and asked for political asylum in Canada, which was granted. The couple now live in Ajax, Ontario, near Toronto, and have two children. In 1996, Phúc met the surgeons who had saved her life. The following year, she passed the Canadian Citizenship Test with a perfect score and became a Canadian citizen. In 2015, it was reported that she was receiving laser treatment at a hospital in Miami, Florida, to reduce the scarring on her left arm and back. The treatment is being provided free of charge.
Kim Phúc Foundation
In
1997 she established the first Kim Phúc Foundation in the U.S., with
the aim of providing medical and psychological assistance to child
victims of war. Later, other foundations were set up, with the same name, under an umbrella organization, Kim Phúc Foundation International.
In 2004, Phúc spoke at the University of Connecticut about her life and experience, learning how to be "strong in the face of pain" and how compassion and love helped her heal.
On December 28, 2009, National Public Radio broadcast her spoken essay, "The Long Road to Forgiveness," for the "This I Believe" series. In May 2010, Phúc was reunited by the BBC with ITN correspondent Christopher Wain, who helped to save her life. On May 18, 2010, Phúc appeared on the BBC Radio 4 programme It's My Story.
In the programme, Phúc related how she was involved through her
foundation in the efforts to secure medical treatment in Canada for Ali Abbas, who had lost both arms in a rocket attack on Baghdad during the invasion of Iraq in 2003.
On February 11, 2019 Kim Phúc was awarded the 2019 Dresden Peace
Prize in recognition of her work with UNESCO and as an activist for
peace.
Recognition
In 1996, Kim Phúc gave a speech at the United States Vietnam Veterans Memorial on Veterans Day.
In her speech, she said that one cannot change the past, but everyone
can work together for a peaceful future. Rev. John Plummer, a Vietnam veteran,
who believed he took part in coordinating the air strike with the
Republic of Vietnam Air Force (though Plummer's entire chain of command
and declassified documents indicate otherwise) met with Phúc briefly and was publicly forgiven. Plummer later admitted to The Baltimore Sun he had lied, saying he was "caught up in the emotion at the Vietnam Veterans Memorial on the day Phuc spoke". Canadian filmmaker, Shelley Saywell, made a documentary about their meeting.
On November 10, 1994, Kim Phúc was named a UNESCO Goodwill Ambassador. Her biography, The Girl in the Picture, was written by Denise Chong
and published in 1999. In 2003, Belgian composer Eric Geurts wrote
"The Girl in the Picture," dedicated to Kim Phúc. It was released on
Flying Snowman Records, with all profits going to the Kim Phúc Foundation. On October 22, 2004, Kim Phúc was made a member of the Order of Ontario, and received an honorary Doctorate of Law from York University
for her work to support child victims of war around the world. On
October 27, 2005, she was awarded an honorary degree in Law from Queen's University in Kingston, Ontario. On June 2, 2011, she was awarded the honorary degree of Doctor of Laws from the University of Lethbridge. On May 19, 2016, she was awarded a Doctor of Civil Law, Honoris Causa by Saint Mary's University (Halifax).
The Girl in the Picture
The Girl in the Picture: The Kim Phúc Story, the Photograph and the Vietnam War by Denise Chong
is a 1999 biographical and historical work tracing the life story of
Kim Phúc. Chong's historical coverage emphasizes the life, especially
the school and family life, of Kim Phúc from before the attack, through
convalescence, and into the present time.
The Girl in the Picture deals primarily with Vietnamese
and American relationships during the Vietnam War, while examining
themes of war, racism, immigration, political turmoil, repression,
poverty, and international relationships through the lens of family and
particularly through the eyes and everyday lives of women. Kim Phúc and
her mother, Nu, provide the lens through which readers of The Girl in the Picture experience war, strife, and the development of communism in Vietnam. Like Chong's first book, The Girl in the Picture was shortlisted for the Governor General's Literary Award for non fiction.
"The Salvation of 'Napalm Girl'"
In a December 21, 2017, article for The Wall Street Journal,
Kim Phúc wrote that the trauma she suffered in the napalm strike still
requires treatment, but that the psychological trauma was greater: "But
even worse than the physical pain was the emotional and spiritual pain."
This led directly to her conversion to Christianity, which she credits
with healing the psychological trauma of living over forty years being
known to the world as "Napalm Girl". "My faith in Jesus Christ is what
has enabled me to forgive those who had wronged me," she wrote, "no
matter how severe those wrongs were."
A Byzantine ship uses Greek fire against a ship of the rebel, Thomas the Slav, 821. 12th century illustration from the Madrid Skylitzes
Greek fire was an incendiary weapon used by the Eastern Roman (Byzantine) Empire beginning c. 672.
Used to set light to enemy ships, it consisted of a combustible
compound emitted by a flame-throwing weapon. Greek fire was first used
by the Greeks besieged in Constantinople (673–78). Some historians
believe it could be ignited on contact with water, and was probably
based on naphtha and quicklime. The Byzantines typically used it in naval battles
to great effect, as it could continue burning while floating on water.
The technological advantage it provided was responsible for many key
Byzantine military victories, most notably the salvation of Constantinople from two Arab sieges, thus securing the Empire's survival.
The impression made by Greek fire on the western European Crusaders was such that the name was applied to any sort of incendiary weapon, including those used by Arabs, the Chinese, and the Mongols. However, these mixtures used different formulas than the Byzantine Greek fire, which was a closely guarded state secret. Byzantines also used pressurized nozzles (siphōns) to project the liquid onto the enemy, in a manner resembling a modern flamethrower.
Although usage of the term "Greek fire" has been general in
English and most other languages since the Crusades, original Byzantine
sources called the substance a variety of names, such as "sea fire" (Medieval Greek: πῦρ θαλάσσιονpŷr thalássion), "Roman fire" (πῦρ ῥωμαϊκόνpŷr rhōmaïkón), "war fire" (πολεμικὸν πῦρpolemikòn pŷr), "liquid fire" (ὑγρὸν πῦρhygròn pŷr), "sticky fire" (πῦρ κολλητικόνpŷr kollētikón), or "manufactured fire" (πῦρ σκευαστόνpŷr skeuastón).
The composition of Greek fire remains a matter of speculation and debate, with various proposals including combinations of pine resin, naphtha, quicklime, calcium phosphide, sulfur, or niter. In his history of Rome, Titus Livy describes priestesses of Bacchus dipping fire into the water, which did not extinguish, "for it was sulphur mixed with lime."
History
Incendiary and flaming weapons were used in warfare for centuries before
Greek fire was invented. They included a number of sulfur-, petroleum-, and bitumen-based mixtures.
Incendiary arrows and pots containing combustible substances surrounded
by caltrops or spikes, or launched by catapults, were used as early as
the 9th century BC by the Assyrians and were extensively used in the Greco-Roman world as well. Furthermore, Thucydides mentions that in the siege of Delium in 424 BC a long tube on wheels was used which blew flames forward using a large bellows.
The Roman author Julius Africanus, writing in the 3rd Century AD,
records a mixture that ignited from adequate heat and intense sunlight,
used in grenades or night attacks:
Automatic fire also
by the following formula. This is the recipe: take equal amounts of
sulphur, rock salt, ashes, thunder stone, and pyrite and pound fine in a
black mortar at midday sun. Also in equal amounts of each ingredient
mix together black mulberry resin and Zakynthian asphault, the latter in
a liquid form and free-flowing, resulting in a product that is sooty
colored. Then add to the asphalt the tiniest amount of quicklime. But
because the sun is at its zenith, one must pound it carefully and
protect the face, for it will ignite suddenly. When it catches fire, one
should seal it in some sort of copper receptacle; in this way you will
have it available in a box, without exposing it to the sun. If you
should wish to ignite enemy armaments, you will smear it on in the
evening, either on the armaments or some other object, but in secret;
when the sun comes up, everything will be burnt up.
In naval warfare, the Eastern Roman Emperor Anastasius I (r. 491–518) is recorded by chronicler John Malalas to have been advised by a philosopher from Athens called Proclus to use sulfur to burn the ships of Vitalianus. Greek fire proper, however, was developed in c. 672 and is ascribed by the chronicler Theophanes to Kallinikos (Latinized Callinicus), an architect from Heliopolis in the former province of Phoenice, by then overrun by the Muslim conquests:
At that time Kallinikos, an
artificer from Heliopolis, fled to the Romans. He had devised a sea fire
which ignited the Arab ships and burned them with all hands. Thus it
was that the Romans returned with victory and discovered the sea fire.
The accuracy and exact chronology of this account is open to question: Theophanes reports the use of fire-carrying and siphōn-equipped ships by the Byzantines a couple of years before the supposed arrival of Kallinikos at Constantinople.
If this is not due to chronological confusion of the events of the
siege, it may suggest that Kallinikos merely introduced an improved
version of an established weapon. The historian James Partington
further thinks it likely that Greek fire was not in fact the creation
of any single person but "invented by chemists in Constantinople who had
inherited the discoveries of the Alexandrian chemical school." Indeed, the 11th-century chronicler George Kedrenos records that Kallinikos came from Heliopolis in Egypt, but most scholars reject this as an error.
Kedrenos also records the story, considered rather implausible by
modern scholars, that Kallinikos' descendants, a family called Lampros, "brilliant," kept the secret of the fire's manufacture and continued doing so to Kedrenos' time.
Kallinikos' development of Greek fire came at a critical moment in the Byzantine Empire's history: weakened by its long wars with Sassanid Persia, the Byzantines had been unable to effectively resist the onslaught of the Muslim conquests. Within a generation, Syria, Palestine, and Egypt had fallen to the Arabs, who in c. 672 set out to conquer the imperial capital of Constantinople. Greek fire was used to great effect against the Muslim fleets, helping to repel the Muslims at the first and second Arab sieges of the city. Records of its use in later naval battles against the Saracens
are more sporadic, but it did secure a number of victories, especially
in the phase of Byzantine expansion in the late 9th and early 10th
centuries.
Utilisation of the substance was prominent in Byzantine civil wars,
chiefly the revolt of the thematic fleets in 727 and the large-scale
rebellion led by Thomas the Slav
in 821–823. In both cases, the rebel fleets were defeated by the
Constantinopolitan Imperial Fleet through the use of Greek fire. The Byzantines also used the weapon to devastating effect against the various Rus' raids on the Bosporus, especially those of 941 and 1043, as well as during the Bulgarian war of 970–971, when the fire-carrying Byzantine ships blockaded the Danube.
The importance placed on Greek fire during the Empire's struggle
against the Arabs would lead to its discovery being ascribed to divine
intervention. The Emperor Constantine Porphyrogennetos (r. 945–959), in his book De Administrando Imperio, admonishes his son and heir, Romanos II
(r. 959–963), to never reveal the secrets of its composition, as it was
"shown and revealed by an angel to the great and holy first Christian
emperor Constantine"
and that the angel bound him "not to prepare this fire but for
Christians, and only in the imperial city." As a warning, he adds that
one official, who was bribed into handing some of it over to the
Empire's enemies, was struck down by a "flame from heaven" as he was
about to enter a church.
As the latter incident demonstrates, the Byzantines could not avoid
capture of their precious secret weapon: the Arabs captured at least one
fireship intact in 827, and the Bulgars captured several siphōns and much of the substance itself in 812/814. This, however, was apparently not enough to allow their enemies to copy it (see below).
The Arabs, for instance, employed a variety of incendiary substances
similar to the Byzantine weapon, but they were never able to copy the
Byzantine method of deployment by siphōn, and used catapults and grenades instead.
Greek fire continued to be mentioned during the 12th century, and Anna Komnene gives a vivid description of its use in a naval battle against the Pisans in 1099. However, although the use of hastily improvised fireships is mentioned during the 1203 siege of Constantinople by the Fourth Crusade,
no report confirms the use of the actual Greek fire. This might be
because of the general disarmament of the Empire in the 20 years leading
up to the sacking, or because the Byzantines had lost access to the
areas where the primary ingredients were to be found, or even perhaps
because the secret had been lost over time.
Records of a 13th-century event in which "Greek fire" was used by
the Saracens against the Crusaders can be read through the Memoirs of
the Lord of Joinville during the Seventh Crusade.
One description of the memoir says "the tail of fire that trailed
behind it was as big as a great spear; and it made such a noise as it
came, that it sounded like the thunder of heaven. It looked like a
dragon flying through the air. Such a bright light did it cast, that one
could see all over the camp as though it were day, by reason of the
great mass of fire, and the brilliance of the light that it shed."
In the 19th century, it is reported that an Armenian by the name of Kavafian approached the government of the Ottoman Empire
with a new type of Greek fire he claimed to have developed. Kavafian
refused to reveal its composition when asked by the government,
insisting that he be placed in command of its use during naval
engagements. Not long after this, he was poisoned by imperial
authorities, without their ever having found out his secret.
Manufacture
General characteristics
As Constantine Porphyrogennetos' warnings show, the ingredients and
the processes of manufacture and deployment of Greek fire were carefully
guarded military secrets. So strict was the secrecy that the
composition of Greek fire was lost forever and remains a source of
speculation.
Consequently, the "mystery" of the formula has long dominated the
research into Greek fire. Despite this almost exclusive focus, however,
Greek fire is best understood as a complete weapon system of many
components, all of which were needed to operate together to render it
effective. This comprised not only the formula of its composition, but
also the specialized dromon ships that carried it into battle, the device used to prepare the substance by heating and pressurizing it, the siphōn projecting it, and the special training of the siphōnarioi who used it. Knowledge of the whole system was highly compartmentalised,
with operators and technicians aware of the secrets of only one
component, ensuring that no enemy could gain knowledge of it in its
entirety. This accounts for the fact that when the Bulgarians took Mesembria and Debeltos in 814, they captured 36 siphōns and even quantities of the substance itself, but were unable to make any use of them.
The information available on Greek fire is exclusively indirect, based on references in the Byzantine military manuals and a number of secondary historical sources such as Anna Komnene and Western European chroniclers, which are often inaccurate. In her Alexiad, Anna Komnene provides a description of an incendiary weapon, which was used by the Byzantine garrison of Dyrrhachium in 1108 against the Normans. It is often regarded as an at least partial "recipe" for Greek fire:
This fire is made by the following arts. From the pine
and the certain such evergreen trees inflammable resin is collected.
This is rubbed with sulfur and put into tubes of reed, and is blown by
men using it with violent and continuous breath. Then in this manner it
meets the fire on the tip and catches light and falls like a fiery
whirlwind on the faces of the enemies.
At the same time, the reports by Western chroniclers of the famed ignis graecus are largely unreliable, since they apply the name to any and all sorts of incendiary substances.
In attempting to reconstruct the Greek fire system, the concrete
evidence, as it emerges from the contemporary literary references,
provides the following characteristics:
It burned on water, and, according to some interpretations, was
ignited by water. In addition, as numerous writers testify, it could be
extinguished only by a few substances, such as sand (which deprived it
of oxygen), strong vinegar, or old urine, presumably by some sort of
chemical reaction.
It was a liquid substance, and not some sort of projectile, as verified both by descriptions and the very name "liquid fire."
At sea, it was usually ejected from a siphōn, although earthenware pots or grenades filled with it or similar substances were also used.
The discharge of Greek fire was accompanied by "thunder" and "much smoke."
Theories on composition
The first and, for a long time, most popular theory regarding the composition of Greek fire held that its chief ingredient was saltpeter, making it an early form of gunpowder.
This argument was based on the "thunder and smoke" description, as well
as on the distance the flame could be projected from the siphōn, which suggested an explosive discharge. From the times of Isaac Vossius,
several scholars adhered to this position, most notably the so-called
"French school" during the 19th century, which included chemist Marcellin Berthelot.
This view has been rejected since, as saltpeter does not appear to have
been used in warfare in Europe or the Middle East before the 13th
century, and is absent from the accounts of the Muslim writers—the foremost chemists of the early medieval world—before the same period. In addition, the nature of the proposed mixture would have been radically different from the siphōn-projected substance described by Byzantine sources.
A second view, based on the fact that Greek fire was
inextinguishable by water (some sources suggest that water intensified
the flames) suggested that its destructive power was the result of the
explosive reaction between water and quicklime. Although quicklime was certainly known and used by the Byzantines and the Arabs in warfare,
the theory is refuted by literary and empirical evidence. A
quicklime-based substance would have to come in contact with water to
ignite, while Emperor Leo's Tactica indicate that Greek fire was often poured directly on the decks of enemy ships, although admittedly, decks were kept wet due to lack of sealants. Likewise, Leo describes the use of grenades, which further reinforces the view that contact with water was not necessary for the substance's ignition.
Furthermore, C. Zenghelis pointed out that, based on experiments, the
actual result of the water–quicklime reaction would be negligible in the
open sea. Another similar proposition suggested that Kallinikos had in fact discovered calcium phosphide, which can be made by boiling bones in urine within a sealed vessel. On contact with water, calcium phosphide releases phosphine,
which ignites spontaneously. However, extensive experiments with it
also failed to reproduce the described intensity of Greek fire.
Consequently, although the presence of either quicklime or
saltpeter in the mixture cannot be entirely excluded, they were not the
primary ingredient. Most modern scholars agree that Greek fire was based on either crude or refined petroleum, comparable to modern napalm. The Byzantines had easy access to crude oil from the naturally occurring wells around the Black Sea (e.g., the wells around Tmutorakan noted by Constantine Porphyrogennetos) or in various locations throughout the Middle East. An alternate name for Greek fire was "Median fire" (μηδικὸν πῦρ), and the 6th-century historian Procopius records that crude oil, called "naphtha" (in Greek: νάφθαnaphtha, from Old Persian𐎴𐎳𐎫naft) by the Persians, was known to the Greeks as "Median oil" (μηδικὸν ἔλαιον). This seems to corroborate the use of naphtha as a basic ingredient of Greek fire. Naphtha was also used by the Abbasids in the 9th century, with special troops, the naffāṭūn, who wore thick protective suits and used small copper vessels containing burning oil, which they threw onto the enemy troops. There is also a surviving 9th century Latin text, preserved at Wolfenbüttel in Germany, which mentions the ingredients of what appears to be Greek fire and the operation of the siphōns used to project it. Although the text contains some inaccuracies, it clearly identifies the main component as naphtha. Resins were probably added as a thickener (the Praecepta Militaria refer to the substance as πῦρ κολλητικόν, "sticky fire"), and to increase the duration and intensity of the flame. A modern theoretical concoction included the use of pine tar and animal fat along with other ingredients.
A 12th century treatise prepared by Mardi bin Ali al-Tarsusi for Saladin records an Arab version of Greek fire, called naft,
which also had a petroleum base, with sulfur and various resins added.
Any direct relation with the Byzantine formula is unlikely. An Italian
recipe from the 16th century has been recorded for recreational use; it
includes coal from a willow tree, alcohol, incense, sulfur, wool and
camphor as well as two undetermined components (burning salt and pegola); the concoction was guaranteed to "burn under water" and to be "beautiful."
Methods of deployment
Use of a cheirosiphōn ("hand-siphōn"), a portable flamethrower, used from atop a flying bridge against a castle. Illumination from the Poliorcetica of Hero of Byzantium.
The chief method of deployment of Greek fire, which sets it apart from similar substances, was its projection through a tube (siphōn), for use aboard ships or in sieges. Portable projectors (cheirosiphōnes, χειροσίφωνες) were also invented, reputedly by Emperor Leo VI. The Byzantine military manuals also mention that jars (chytrai or tzykalia) filled with Greek fire and caltrops wrapped with tow and soaked in the substance were thrown by catapults, while pivoting cranes (gerania) were employed to pour it upon enemy ships. The cheirosiphōnes especially were prescribed for use at land and in sieges, both against siege machines and against defenders on the walls, by several 10th-century military authors, and their use is depicted in the Poliorcetica of Hero of Byzantium. The Byzantine dromons usually had a siphōn
installed on their prow under the forecastle, but additional devices
could also on occasion be placed elsewhere on the ship. Thus in 941,
when the Byzantines were facing the vastly more numerous Rus' fleet, siphōns were placed also amidships and even astern.
Projectors
The use of tubular projectors (σίφων, siphōn)
is amply attested in the contemporary sources. Anna Komnene gives this
account of beast-shaped Greek fire projectors being mounted to the bow
of warships:
As he [the Emperor Alexios I] knew that the Pisans
were skilled in sea warfare and dreaded a battle with them, on the prow
of each ship he had a head fixed of a lion or other land-animal, made
in brass or iron with the mouth open and then gilded over, so that their
mere aspect was terrifying. And the fire which was to be directed
against the enemy through tubes he made to pass through the mouths of
the beasts, so that it seemed as if the lions and the other similar
monsters were vomiting the fire.
Some sources provide more information on the composition and function
of the whole mechanism. The Wolfenbüttel manuscript in particular
provides the following description:
...having built a furnace right at the front of the ship,
they set on it a copper vessel full of these things, having put fire
underneath. And one of them, having made a bronze tube similar to that
which the rustics call a squitiatoria, "squirt," with which boys play, they spray [it] at the enemy.
[They] began blowing with smiths’ bellows at a furnace in
which there was fire and there came from it a great din. There stood
there also a brass [or bronze] tube and from it flew much fire against
one ship, and it burned up in a short time so that all of it became
white ashes...
The account, albeit embellished, corresponds with many of the
characteristics of Greek fire known from other sources, such as a loud
roar that accompanied its discharge.
These two texts are also the only two sources that explicitly mention
that the substance was heated over a furnace before being discharged;
although the validity of this information is open to question, modern
reconstructions have relied upon them.
Proposed reconstruction of the Greek fire mechanism by Haldon and Byrne
Based on these descriptions and the Byzantine sources, John Haldon
and Maurice Byrne designed a hypothetical apparatus as consisting of
three main components: a bronze pump, which was used to pressurize the
oil; a brazier, used to heat the oil (πρόπυρον, propyron, "pre-heater"); and the nozzle, which was covered in bronze and mounted on a swivel (στρεπτόν, strepton).
The brazier, burning a match of linen or flax that produced intense
heat and the characteristic thick smoke, was used to heat oil and the
other ingredients in an airtight tank above it, a process that also helped to dissolve the resins into a fluid mixture.
The substance was pressurized by the heat and the usage of a force
pump. After it had reached the proper pressure, a valve connecting the
tank with the swivel was opened and the mixture was discharged from its
end, being ignited at its mouth by some source of flame. The intense heat of the flame made necessary the presence of heat shields made of iron (βουκόλια, boukolia), which are attested in the fleet inventories.
The process of operating Haldon and Byrne's design was fraught
with danger, as the mounting pressure could easily make the heated oil
tank explode, a flaw which was not recorded as a problem with the
historical fire weapon. In the experiments conducted by Haldon in 2002 for the episode "Fireship" of the television series Machines Times Forgot,
even modern welding techniques failed to secure adequate insulation of
the bronze tank under pressure. This led to the relocation of the
pressure pump between the tank and the nozzle. The full-scale device
built on this basis established the effectiveness of the mechanism's
design, even with the simple materials and techniques available to the
Byzantines. The experiment used crude oil mixed with wood resins, and
achieved a flame temperature of over 1,000 °C (1,830 °F) and an
effective range of up to 15 meters (49 ft).
Hand-held projectors
Detail of a cheirosiphōn
The portable cheirosiphōn ("hand-siphōn"), the earliest analogue to a modern flamethrower,
is extensively attested in the military documents of the 10th century,
and recommended for use in both sea and land. They first appear in the Tactica of emperor Leo VI the Wise, who claims to have invented them. Subsequent authors continued to refer to the cheirosiphōnes, especially for use against siege towers, although Nikephoros II Phokas also advises their use in field armies, with the aim of disrupting the enemy formation. Although both Leo VI and Nikephoros Phokas claim that the substance used in the cheirosiphōnes
was the same as in the static devices used on ships, Haldon and Byrne
consider that the former were manifestly different from their larger
cousins, and theorize that the device was fundamentally different, "a
simple syringe [that] squirted both liquid fire (presumably unignited)
and noxious juices to repel enemy troops." The illustrations of Hero's Poliorcetica show the cheirosiphōn also throwing the ignited substance.
Grenades
Ceramic grenades that were filled with Greek fire, surrounded by caltrops, 10th–12th century, National Historical Museum, Athens, Greece
In its earliest form, Greek fire was hurled onto enemy forces by
firing a burning cloth-wrapped ball, perhaps containing a flask, using a
form of light catapult, most probably a seaborne variant of the Roman light catapult or onager. These were capable of hurling light loads, around 6 to 9 kg (13 to 20 lb), a distance of 350–450 m (380–490 yd).
Effectiveness and countermeasures
Although the destructiveness of Greek fire is indisputable, it did not make the Byzantine navy invincible. It was not, in the words of naval historian John Pryor, a "ship-killer" comparable to the naval ram, which, by then, had fallen out of use.
While Greek fire remained a potent weapon, its limitations were
significant when compared to more traditional forms of artillery: in its
siphōn-deployed version, it had a limited range, and it could be used safely only in a calm sea and with favourable wind conditions.
The Muslim navies eventually adapted themselves to it by staying
out of its effective range and devising methods of protection such as
felt or hides soaked in vinegar.
In literature
In William Golding's 1958 play The Brass Butterfly, derived from his Envoy Extraordinary (novella),
the Greek inventor Phanocles demonstrates explosives to the emperor
Mamillius. The emperor decides that his empire is not ready for this or
for Phanocles's other inventions and sends him on "a slow boat to
China".
In Victor Canning's stage play Honour Bright (1960), the crusader Godfrey of Ware returns with a casket of Greek Fire given to him by an old man in Athens.
In C. J. Sansom's historical mystery novel Dark Fire, Thomas Cromwell sends the lawyer Matthew Shardlake to recover the secret of Greek fire, following its discovery in the library of a dissolved London monastery.
In Mika Waltari's novel The Dark Angel,
some old men who are the last ones who know the secret of Greek fire
are mentioned as present in the last Christian services held in Hagia Sophia before the Fall of Constantinople. The narrator is told that in the event of the city's fall, they will be killed so as to keep the secret from the Turks.
In George R. R. Martin's fantasy series of novels A Song of Ice and Fire, and its television adaptation Game of Thrones,
wildfire is similar to Greek fire. It was used in naval battles as it
could remain lit on water, and its recipe was jealously guarded.
Oil refineries are typically large, sprawling industrial complexes with extensive piping running throughout, carrying streams of fluids between large chemical processing units, such as distillation columns. In many ways, oil refineries use much of the technology, and can be thought of, as types of chemical plants.
The crude oil feedstock has typically been processed by an oil production plant. There is usually an oil depot at or near an oil refinery for the storage of incoming crude oil feedstock as well as bulk liquid products.
Petroleum refineries are very large industrial complexes that
involve many different processing units and auxiliary facilities such as
utility units and storage tanks. Each refinery has its own unique
arrangement and combination of refining processes largely determined by
the refinery location, desired products and economic considerations.
Some modern petroleum refineries process as much as 800,000 to
900,000 barrels (127,000 to 143,000 cubic meters) of crude oil per day.
According to the Oil and Gas Journal in the world a total of 636
refineries were operated on the 31 December 2014 for a total capacity of
87.75 million barrels (13,951,000 m3).
Jamnagar Refinery is the largest oil refinery, since 25 December 2008, with a processing capacity of 1.24 million barrels (197,000 m3). Located in Gujarat, India, it is owned by Reliance Industries.
History
The Chinese were among the first civilizations to refine oil. As early as the first century, the Chinese were refining crude oil for use as an energy source. Between 512 and 518, in the late Northern Wei Dynasty, the Chinese geographer, writer and politician Li Daoyuan introduced the process of refining oil into various lubricants in his famous work Commentary on the Water Classic.
In the Northern Song Dynasty
(960–1127), a workshop called the "Fierce Oil Workshop", was
established in the city of Kaifeng to produce refined oil for the Song
military as a weapon. The troops would then fill iron cans with refined
oil and throw them toward the enemy troops, causing a fire – effectively
the world's first "fire bomb".
The workshop was one of the world's earliest oil refining factories
where thousands of people worked to produce Chinese oil powered
weaponry.
Prior to the nineteenth century, petroleum was known and utilized in various fashions in Babylon, Egypt, China, Philippines, Rome and Azerbaijan. However, the modern history of the petroleum industry is said to have begun in 1846 when Abraham Gessner of Nova Scotia, Canada devised a process to produce kerosene from coal. Shortly thereafter, in 1854, Ignacy Łukasiewicz began producing kerosene from hand-dug oil wells near the town of Krosno, Poland.
The world's first systematic petroleum refinery was built in Ploiești, Romania in 1856 using the abundant oil available in Romania.
In North America, the first oil well was drilled in 1858 by James Miller Williams in Oil Springs, Ontario, Canada. In the United States, the petroleum industry began in 1859 when Edwin Drake found oil near Titusville, Pennsylvania.
The industry grew slowly in the 1800s, primarily producing kerosene for
oil lamps. In the early twentieth century, the introduction of the
internal combustion engine and its use in automobiles created a market
for gasoline that was the impetus for fairly rapid growth of the
petroleum industry. The early finds of petroleum like those in Ontario
and Pennsylvania were soon outstripped by large oil "booms" in Oklahoma, Texas and California.
Samuel Kier established America's first oil refinery in Pittsburgh on Seventh avenue near Grant Street, in 1853. Polish pharmacist and inventor Ignacy Łukasiewicz established an oil refinery in Jasło, then part of the Austro-Hungarian Empire (now in Poland) in 1854. The first large refinery opened at Ploiești, Romania, in 1856–1857. After being taken over by Nazi Germany, the Ploiești refineries were bombed in Operation Tidal Wave by the Allies during the Oil Campaign of World War II. Another close contender for the title of hosting the world's oldest oil refinery is Salzbergen in Lower Saxony, Germany. Salzbergen's refinery was opened in 1860.
At one point, the refinery in Ras Tanura, Saudi Arabia owned by Saudi Aramco was claimed to be the largest oil refinery in the world. For most of the 20th century, the largest refinery was the Abadan Refinery in Iran. This refinery suffered extensive damage during the Iran–Iraq War. Since 25 December 2008, the world's largest refinery complex is the Jamnagar Refinery Complex, consisting of two refineries side by side operated by Reliance Industries Limited in Jamnagar, India with a combined production capacity of 1,240,000 barrels per day (197,000 m3/d). PDVSA's Paraguaná Refinery Complex in Paraguaná Peninsula, Venezuela with a capacity of 940,000 bbl/d (149,000 m3/d) and SK Energy's Ulsan in South Korea with 840,000 bbl/d (134,000 m3/d) are the second and third largest, respectively.
Prior to World War II in the early 1940s, most petroleum
refineries in the United States consisted simply of crude oil
distillation units (often referred to as atmospheric crude oil
distillation units). Some refineries also had vacuum distillation units as well as thermal cracking units such as visbreakers (viscosity breakers, units to lower the viscosity
of the oil). All of the many other refining processes discussed below
were developed during the war or within a few years after the war. They
became commercially available within 5 to 10 years after the war ended
and the worldwide petroleum industry experienced very rapid growth. The
driving force for that growth in technology and in the number and size
of refineries worldwide was the growing demand for automotive gasoline
and aircraft fuel.
In the United States, for various complex economic and political
reasons, the construction of new refineries came to a virtual stop in
about the 1980s. However, many of the existing refineries in the United
States have revamped many of their units and/or constructed add-on units
in order to: increase their crude oil processing capacity, increase the
octane rating of their product gasoline, lower the sulfur
content of their diesel fuel and home heating fuels to comply with
environmental regulations and comply with environmental air pollution
and water pollution requirements.
The size of oil refining market in 2017 was valued over USD 6
trillion in 2017 and is set to witness a consumption of over 100 million
barrels per day (MBPD) by 2024. Oil refining market will witness an
appreciable growth because of rapid industrialization and economic
transformation. Changing demographics, growing population and
improvement in living standards across developing nations are some of
factors positively influencing the industry landscape.
Oil refining in the United States
In the 19th century, refineries in the U.S. processed crude oil primarily to recover the kerosene.
There was no market for the more volatile fraction, including gasoline,
which was considered waste and was often dumped directly into the
nearest river. The invention of the automobile shifted the demand to
gasoline and diesel, which remain the primary refined products today.
Today, national and state legislation require refineries to meet
stringent air and water cleanliness standards. In fact, oil companies in
the U.S. perceive obtaining a permit to build a modern refinery to be
so difficult and costly that no new refineries were built (though many
have been expanded) in the U.S. from 1976 until 2014, when the small
Dakota Prairie Refinery in North Dakota began operation. More than half the refineries that existed in 1981 are now closed due to low utilization rates and accelerating mergers.
As a result of these closures total US refinery capacity fell between
1981 and 1995, though the operating capacity stayed fairly constant in
that time period at around 15,000,000 barrels per day (2,400,000 m3/d).
Increases in facility size and improvements in efficiencies have offset
much of the lost physical capacity of the industry. In 1982 (the
earliest data provided), the United States operated 301 refineries with a
combined capacity of 17.9 million barrels (2,850,000 m3) of
crude oil each calendar day. In 2010, there were 149 operable U.S.
refineries with a combined capacity of 17.6 million barrels (2,800,000 m3) per calendar day. By 2014 the number of refinery had reduced to 140 but the total capacity increased to 18.02 million barrels (2,865,000 m3)
per calendar day. Indeed, in order to reduce operating costs and
depreciation, refining is operated in fewer sites but of bigger
capacity.
In 2009 through 2010, as revenue streams in the oil business
dried up and profitability of oil refineries fell due to lower demand
for product and high reserves of supply preceding the economic recession, oil companies began to close or sell the less profitable refineries.
Operation
Raw or unprocessed crude oil is not generally useful in industrial applications, although "light, sweet" (low viscosity, low sulfur)
crude oil has been used directly as a burner fuel to produce steam for
the propulsion of seagoing vessels. The lighter elements, however, form
explosive vapors in the fuel tanks and are therefore hazardous,
especially in warships.
Instead, the hundreds of different hydrocarbon molecules in crude oil
are separated in a refinery into components that can be used as fuels, lubricants, and feedstocks in petrochemical processes that manufacture such products as plastics, detergents, solvents, elastomers, and fibers such as nylon and polyesters.
Petroleumfossil fuels are burned in internal combustion engines to provide power for ships, automobiles, aircraft engines, lawn mowers, dirt bikes, and other machines. Different boiling points allow the hydrocarbons to be separated by distillation.
Since the lighter liquid products are in great demand for use in
internal combustion engines, a modern refinery will convert heavy
hydrocarbons and lighter gaseous elements into these higher value
products.
The oil refinery in Haifa, Israel is capable of processing about 9 million tons (66 million barrels) of crude oil a year. Its two cooling towers are landmarks of the city's skyline.
Oil can be used in a variety of ways because it contains hydrocarbons of varying molecular masses, forms and lengths such as paraffins, aromatics, naphthenes (or cycloalkanes), alkenes, dienes, and alkynes.
While the molecules in crude oil include different atoms such as sulfur
and nitrogen, the hydrocarbons are the most common form of molecules,
which are molecules of varying lengths and complexity made of hydrogen and carbonatoms, and a small number of oxygen atoms. The differences in the structure of these molecules account for their varying physical and chemical properties, and it is this variety that makes crude oil useful in a broad range of several applications.
Once separated and purified of any contaminants and impurities,
the fuel or lubricant can be sold without further processing. Smaller
molecules such as isobutane and propylene or butylenes can be recombined to meet specific octane requirements by processes such as alkylation, or more commonly, dimerization. The octane grade of gasoline can also be improved by catalytic reforming, which involves removing hydrogen from hydrocarbons producing compounds with higher octane ratings such as aromatics. Intermediate products such as gasoils can even be reprocessed to break a heavy, long-chained oil into a lighter short-chained one, by various forms of cracking such as fluid catalytic cracking, thermal cracking, and hydrocracking. The final step in gasoline production is the blending of fuels with different octane ratings, vapor pressures,
and other properties to meet product specifications. Another method for
reprocessing and upgrading these intermediate products (residual oils)
uses a devolatilization process to separate usable oil from the waste asphaltene material.
Oil refineries are large scale plants, processing about a hundred thousand to several hundred thousand barrels of crude oil a day. Because of the high capacity, many of the units operate continuously, as opposed to processing in batches, at steady state or nearly steady state for months to years. The high capacity also makes process optimization and advanced process control very desirable.
Major products
Crude oil is separated into fractions by fractional distillation. The fractions at the top of the fractionating column have lower boiling points than the fractions at the bottom. The heavy bottom fractions are often cracked into lighter, more useful products. All of the fractions are processed further in other refining units.
A breakdown of the products made from a typical barrel of US oil.
Petroleum products are materials derived from crude oil (petroleum) as it is processed in oil refineries. The majority of petroleum is converted to petroleum products, which includes several classes of fuels.
Oil refineries also produce various intermediate products such as hydrogen, light hydrocarbons, reformate and pyrolysis gasoline.
These are not usually transported but instead are blended or processed
further on-site. Chemical plants are thus often adjacent to oil
refineries or a number of further chemical processes are integrated into
it. For example, light hydrocarbons are steam-cracked in an ethylene plant, and the produced ethylene is polymerized to produce polyethene.
Because technical reasons and environment protection demand a
very low sulfur content in all but the heaviest products, it is
transformed to hydrogen sulfide via catalytic hydrodesulfurization and removed from the product stream via amine gas treating. Using the Claus process,
hydrogen sulfide is afterwards transformed to elementary sulfur to be
sold to the chemical industry. The rather large heat energy freed by
this process is directly used in the other parts of the refinery. Often
an electrical power plant is combined into the whole refinery process to
take up the excess heat.
According to the composition of the crude oil and depending on
the demands of the market, refineries can produce different shares of
petroleum products. The largest share of oil products is used as "energy
carriers", i.e. various grades of fuel oil and gasoline. These fuels include or can be blended to give gasoline, jet fuel, diesel fuel, heating oil, and heavier fuel oils. Heavier (less volatile) fractions can also be used to produce asphalt, tar, paraffin wax, lubricating and other heavy oils. Refineries also produce other chemicals, some of which are used in chemical processes to produce plastics and other useful materials. Since petroleum often contains a few percent sulfur-containing molecules, elemental sulfur is also often produced as a petroleum product. Carbon, in the form of petroleum coke, and hydrogen
may also be produced as petroleum products. The hydrogen produced is
often used as an intermediate product for other oil refinery processes
such as hydrocracking and hydrodesulfurization.
Petroleum products are usually grouped into four categories:
light distillates (LPG, gasoline, naphtha), middle distillates
(kerosene, jet fuel, diesel), heavy distillates and residuum (heavy fuel
oil, lubricating oils, wax, asphalt). These require blending various
feedstocks, mixing appropriate additives, providing short term storage,
and preparation for bulk loading to trucks, barges, product ships, and
railcars. This classification is based on the way crude oil is distilled
and separated into fractions.
Lubricants (produces light machine oils, motor oils, and greases, adding viscosity stabilizers as required), usually shipped in bulk to an offsite packaging plant.
Paraffin wax, used in the packaging of frozen foods,
among others. May be shipped in bulk to a site to prepare as packaged
blocks. Used for wax emulsions, construction board, matches, candles,
rust protection, and vapor barriers.
Sulfur (or sulfuric acid),
byproducts of sulfur removal from petroleum which may have up to a
couple percent sulfur as organic sulfur-containing compounds. Sulfur and
sulfuric acid are useful industrial materials. Sulfuric acid is
usually prepared and shipped as the acid precursor oleum.
Bulk tar shipping for offsite unit packaging for use in tar-and-gravel roofing.
Asphalt used as a binder for gravel to form asphalt concrete, which is used for paving roads, lots, etc. An asphalt unit prepares bulk asphalt for shipment.
Petrochemicals are organic compounds that are the ingredients for the chemical industry, ranging from polymers and pharmaceuticals, including ethylene and benzene-toluene-xylenes ("BTX") which are often sent to petrochemical plants for further processing in a variety of ways. The petrochemicals may be olefins or their precursors, or various types of aromatic petrochemicals.
Desalter unit washes out salt from the crude oil before it enters the atmospheric distillation unit.
Crude Oil Distillation unit (Atmospheric distillation): Distills the
incoming crude oil into various fractions for further processing in
other units. See continuous distillation.
Vacuum distillation
further distills the residue oil from the bottom of the crude oil
distillation unit. The vacuum distillation is performed at a pressure
well below atmospheric pressure.
Naphtha hydrotreater unit uses hydrogen to desulfurize naphtha from atmospheric distillation. Must hydrotreat the naphtha before sending to a catalytic reformer unit.
Catalytic reformer converts the desulfurized naphthamolecules into higher-octane molecules to produce reformate
(reformer product). The reformate has higher content of aromatics and
cyclic hydrocarbons which is a component of the end-product gasoline or
petrol. An important byproduct of a reformer is hydrogen released during
the catalyst reaction. The hydrogen is used either in the hydrotreaters
or the hydrocracker.
Distillate hydrotreater desulfurizes distillates (such as diesel) after atmospheric distillation. Uses hydrogen to desulfurize the naphtha fraction from the crude oil distillation or other units within the refinery.
Fluid Catalytic Cracker
(FCC) upgrades the heavier, higher-boiling fractions from the crude oil
distillation by converting them into lighter and lower boiling, more
valuable products.
Hydrocracker
uses hydrogen to upgrade heavy residual oils from the vacuum
distillation unit by thermally cracking them into lighter, more valuable
reduced viscosity products.
Alternative processes for removing mercaptans are known, e.g. doctor sweetening process and caustic washing.
Coking units (delayed coking,
fluid coker, and flexicoker) process very heavy residual oils into
gasoline and diesel fuel, leaving petroleum coke as a residual product.
Alkylation unit uses sulfuric acid or hydrofluoric acid to produce high-octane components for gasoline blending. Converts isobutane and butylenes into alkylate, which is a very high-octane component of the end-product gasoline or petrol.
Dimerization unit converts olefins into higher-octane gasoline blending components. For example, butenes can be dimerized into isooctene which may subsequently be hydrogenated to form isooctane.
There are also other uses for dimerization. Gasoline produced through
dimerization is highly unsaturated and very reactive. It tends
spontaneously to form gums. For this reason the effluent from the
dimerization need to be blended into the finished gasoline pool
immediately or hydrogenated.
Isomerization converts linear molecules such as normal pentane to higher-octane branched molecules for blending into gasoline or feed to alkylation units. Also used to convert linear normal butane into isobutane for use in the alkylation unit.
Steam reforming converts natural gas into hydrogen for the hydrotreaters and/or the hydrocracker.
Liquified gas storage vessels store propane and similar gaseous
fuels at pressure sufficient to maintain them in liquid form. These are
usually spherical vessels or "bullets" (i.e., horizontal vessels with
rounded ends).
Sour water stripper
Uses steam to remove hydrogen sulfide gas from various wastewater
streams for subsequent conversion into end-product sulfur in the Claus
unit.
Solvent refining use solvent such as cresol or furfural to remove unwanted, mainly aromatics from lubricating oil stock or diesel stock.
Solvent dewaxing remove the heavy waxy constituents petrolatum from vacuum distillation products.
Liquified gas (LPG) storage vessels for propane and similar gaseous
fuels at a pressure sufficient to maintain them in liquid form. These
are usually spherical vessels or bullets (horizontal vessels with rounded ends).
Storage tanks for storing crude oil and finished products, usually
vertical, cylindrical vessels with some sort of vapour emission control
and surrounded by an earthen berm to contain spills.
Flow diagram of typical refinery
The image below is a schematic flow diagram of a typical oil refinery that depicts the various unit
processes and the flow of intermediate product streams that occurs
between the inlet crude oil feedstock and the final end products. The diagram
depicts only one of the literally hundreds of different oil refinery
configurations. The diagram also does not include any of the usual
refinery facilities providing utilities such as steam, cooling water,
and electric power as well as storage tanks for crude oil feedstock and
for intermediate products and end products.
Schematic flow diagram of a typical oil refinery
There are many process configurations other than that depicted above. For example, the vacuum distillation
unit may also produce fractions that can be refined into end products
such as: spindle oil used in the textile industry, light machinery oil,
motor oil, and various waxes.
The crude oil distillation unit
The
crude oil distillation unit (CDU) is the first processing unit in
virtually all petroleum refineries. The CDU distills the incoming crude
oil into various fractions of different boiling ranges, each of which
are then processed further in the other refinery processing units. The
CDU is often referred to as the atmospheric distillation unit because it operates at slightly above atmospheric pressure.
Below is a schematic flow diagram of a typical crude oil
distillation unit. The incoming crude oil is preheated by exchanging
heat with some of the hot, distilled fractions and other streams. It is
then desalted to remove inorganic salts (primarily sodium chloride).
Following the desalter, the crude oil is further heated by
exchanging heat with some of the hot, distilled fractions and other
streams. It is then heated in a fuel-fired furnace (fired heater) to a
temperature of about 398 °C and routed into the bottom of the
distillation unit.
The cooling and condensing of the distillation tower overhead is
provided partially by exchanging heat with the incoming crude oil and
partially by either an air-cooled or water-cooled condenser. Additional
heat is removed from the distillation column by a pumparound system as
shown in the diagram below.
As shown in the flow diagram, the overhead distillate fraction
from the distillation column is naphtha. The fractions removed from the
side of the distillation column at various points between the column top
and bottom are called sidecuts. Each of the sidecuts (i.e., the
kerosene, light gas oil and heavy gas oil) is cooled by exchanging heat
with the incoming crude oil. All of the fractions (i.e., the overhead
naphtha, the sidecuts and the bottom residue) are sent to intermediate
storage tanks before being processed further.
Schematic flow diagram of a typical crude oil distillation unit as used in petroleum crude oil refineries.
Location of petroleum refineries
A party searching for a site to construct a refinery or a chemical plant needs to consider the following issues:
The site has to be reasonably far from residential areas.
Infrastructure should be available for supply of raw materials and shipment of products to markets.
Energy to operate the plant should be available.
Facilities should be available for waste disposal.
Refineries which use a large amount of steam and cooling water need
to have an abundant source of water. Oil refineries therefore are often
located nearby navigable rivers or on a sea shore, nearby a port. Such
location also gives access to transportation by river or by sea. The
advantages of transporting crude oil by pipeline are evident, and oil
companies often transport a large volume of fuel to distribution
terminals by pipeline. Pipeline may not be practical for products with
small output, and rail cars, road tankers, and barges are used.
Petrochemical plants and solvent manufacturing (fine
fractionating) plants need spaces for further processing of a large
volume of refinery products for further processing, or to mix chemical
additives with a product at source rather than at blending terminals.
Many governments worldwide have mandated restrictions on
contaminants that refineries release, and most refineries have installed
the equipment needed to comply with the requirements of the pertinent
environmental protection regulatory agencies. In the United States,
there is strong pressure to prevent the development of new refineries,
and no major refinery has been built in the country since Marathon'sGaryville, Louisiana
facility in 1976. However, many existing refineries have been expanded
during that time. Environmental restrictions and pressure to prevent
construction of new refineries may have also contributed to rising fuel
prices in the United States.
Additionally, many refineries (more than 100 since the 1980s) have
closed due to obsolescence and/or merger activity within the industry
itself.
Environmental and safety concerns mean that oil refineries are
sometimes located some distance away from major urban areas.
Nevertheless, there are many instances where refinery operations are
close to populated areas and pose health risks. In California's Contra Costa County and Solano County,
a shoreline necklace of refineries, built in the early 20th century
before this area was populated, and associated chemical plants are adjacent to urban areas in Richmond, Martinez, Pacheco, Concord, Pittsburg, Vallejo and Benicia, with occasional accidental events that require "shelter in place" orders to the adjacent populations. A number of refineries are located in Sherwood Park, Alberta, directly adjacent to the City of Edmonton. The Edmonton metro area has a population of over 1,000,000 residents.
Modern petroleum refining involves a complicated system of interrelated chemical reactions that produce a wide variety of petroleum-based products. Many of these reactions require precise temperature and pressure parameters.
The equipment and monitoring required to ensure the proper progression
of these processes is complex, and has evolved through the advancement
of the scientific field of petroleum engineering.
The wide array of high pressure and/or high temperature
reactions, along with the necessary chemical additives or extracted
contaminants, produces an astonishing number of potential health hazards
to the oil refinery worker.
Through the advancement of technical chemical and petroleum
engineering, the vast majority of these processes are automated and
enclosed, thus greatly reducing the potential health impact to workers.
However, depending on the specific process in which a worker is
engaged, as well as the particular method employed by the refinery in
which he/she works, significant health hazards remain.
Although U.S. occupational injuries were not routinely
tracked/reported at the time, reports of the health impacts of working
in an oil refinery can be found as early as the 1800s. For instance, an
explosion in a Chicago refinery killed 20 workers in 1890.
Since then, numerous fires, explosions, and other significant events
have from time to time drawn the public's attention to the health of oil
refinery workers. Such events continue today, with explosions reported in refineries in Wisconsin and Germany in 2018.
However, there are many less visible hazards that endanger oil refinery workers.
Chemical exposures
Given
the highly automated and technically advanced nature of modern
petroleum refineries, nearly all processes are contained within
engineering controls and represent a substantially decreased risk of
exposure to workers compared to earlier times.
However, certain situations or work tasks may subvert these safety
mechanisms, and expose workers to a number of chemical (see table above)
or physical (described below) hazards. Examples of these scenarios include:
System failures (leaks, explosions, etc.).
Standard inspection, product sampling, process turnaround, or equipment maintenance/cleaning activities.
Interestingly, even though petroleum refineries utilize and produce chemicals that are known carcinogens, the literature on cancer rates among refinery workers is mixed. For example, benzene has been shown to have a relationship with leukemia,
however studies examining benzene exposure and resultant leukemia
specifically in the context of oil refinery workers have come to
opposing conclusions. Asbestos-related mesothelioma
is another particular cancer-carcinogen relationship that has been
investigated in the context of oil refinery workers. To date, this work
has shown a marginally significant link to refinery employment and
mesothelioma.
Notably, a meta-analysis which included data on more than 350,000
refinery workers failed to find any statistically significant excess
rates of cancer mortality, except for a marginally significant increase
in melanoma deaths.
An additional U.S.-based study included a follow-up period of 50 years
among over 17,000 workers. This study concluded that there was no
excess mortality among this cohort as a result of employment.
BTX stands for benzene, toluene, xylene. This is a group of common volatile organic compounds
(VOC's) that are found in the oil refinery environment, and serve as a
paradigm for more in depth discussion of occupational exposure limits,
chemical exposure and surveillance among refinery workers.
The most important route of exposure for BTEX chemicals is
inhalation due to the low boiling point of these chemicals. The
majority of the gaseous production of BTEX occurs during tank cleaning
and fuel transfer, which causes offgassing of these chemicals into the
air. Exposure can also occur through ingestion via contaminated water, but this is unlikely in an occupational setting.
Dermal exposure and absorption is also possible, but is again less
likely in an occupational setting where appropriate personal protective
equipment is in place.
Benzene, in particular, has multiple biomarkers
that can be measured to determine exposure. Benzene itself can be
measured in the breath, blood, and urine, and metabolites such as phenol, t,t-muconic acid (t,tMA) and S-phenylmercapturic acid (sPMA) can be measured in urine.
In addition to monitoring the exposure levels via these biomarkers,
employers are required by OSHA to perform regular blood tests on workers
to test for early signs of some of the feared hematologic outcomes, of
which the most widely recognized is leukemia. Required testing includes complete blood count with cell differentials and peripheral blood smear "on a regular basis". The utility of these tests is supported by formal scientific studies.
Physical hazards
Workers
are at risk of physical injuries due to the large number of
high-powered machines in the relatively close proximity of the oil
refinery. The high pressure required for many of the chemical reactions
also presents the possibility of localized system failures resulting in
blunt or penetrating trauma from exploding system components.
However, Bureau of Labor (BLS) statistical reports indicate that
petroleum refinery workers have a significantly lower rate of
occupational injury (0.7 OSHA-recordable cases per 100 full-time
workers) than all industries (3.1), oil and gas extraction (1.0), and
petroleum manufacturing in general (1.6).
Heat is also a hazard. The temperature required for the proper
progression of certain reactions in the refining process can reach 1600
degrees F.
As with chemicals, the operating system is designed to safely contain
this hazard without injury to the worker. However, in system failures
this is a potent threat to workers’ health. Concerns include both
direct injury through a heat illness or injury, as well as the potential for devastating burns should the worker come in contact with super-heated reagents/equipment.
Noise is another hazard. Refineries can be very loud
environments, and have previously been shown to be associated with
hearing loss among workers. The interior environment of an oil refinery can reach levels in excess of 90 dB. An average of 90 dB is the OSHA Permissible Exposure Limit (PEL) for an 8 hour work-day. Noise exposures that average greater than 85 dB over an 8 hour require a hearing conservation program to regularly evaluate workers' hearing and to promote its protection. Regular evaluation of workers’ auditory capacity and faithful use of properly vetted hearing protection are essential parts of such programs.
The theory of hierarchy of controls can be applied to petroleum refineries and their efforts to ensure worker safety.
Elimination and substitution
are unlikely in petroleum refineries, as many of the raw materials,
waste products, and finished products are hazardous in one form or
another (e.g. flammable, carcinogenic).
Examples of engineering controls include a fire detection/extinguishing system, pressure/chemical sensors to detect/predict loss of structural integrity, and adequate maintenance of piping to prevent hydrocarbon-induced corrosion (leading to structural failure). Other examples employed in petroleum refineries include the post-construction protection of steel components with vermiculite to improve heat/fire resistance. Compartmentalization
can help to prevent a fire or other systems failure from spreading to
affect other areas of the structure, and may help prevent dangerous
reactions by keeping difference chemicals separate from one another
until they can be safely combined in the proper environment.
Administrative controls
include careful planning and oversight of the refinery cleaning,
maintenance, and turnaround processes. These occur when many of the
engineering controls are shut down or suppressed, and may be especially
dangerous to workers. Detailed coordination is necessary to ensure that
maintenance of one part of the facility will not cause dangerous
exposures to those performing the maintenance, or to workers in other
areas of the plant. Due to the highly flammable nature of many of the
involved chemical, smoking areas are tightly controlled and carefully
placed.
Personal protective equipment
may be necessary depending on the specific chemical being processed or
produced. Particular care is needed during sampling of the
partially-completed product, tank cleaning, and other high-risk tasks as
mentioned above. Such activities may require the use of impervious
outer wear, acid hood, disposable coveralls, etc. More generally, all personnel in operating areas should use appropriate hearing and vision protection, avoid clothes made of flammable material (nylon, Dacron, acrylic, or blends), and full-length pants/sleeves.
Regulations
Worker health and safety in oil refineries is closely monitored by both OSHA and NIOSH. CalOSHA
has been particularly active in regulating worker health in this
industry, and adopted a policy in 2017 that requires petroleum
refineries to perform a Hierarchy of Hazard Controls Analysis (see above
"Controls" section) for each process safety hazard.
Below is a list of the most common regulations referenced in petroleum refinery safety citations issued by OSHA:
Corrosion of metallic components is a major factor of inefficiency in
the refining process. Because it leads to equipment failure, it is a
primary driver for the refinery maintenance schedule. Corrosion-related
direct costs in the U.S. petroleum industry as of 1996 were estimated at
US $3.7 billion.
Corrosion occurs in various forms in the refining process, such
as pitting corrosion from water droplets, embrittlement from hydrogen,
and stress corrosion cracking from sulfide attack.
From a materials standpoint, carbon steel is used for upwards of 80 per
cent of refinery components, which is beneficial due to its low cost. Carbon steel
is resistant to the most common forms of corrosion, particularly from
hydrocarbon impurities at temperatures below 205 °C, but other corrosive
chemicals and environments prevent its use everywhere. Common
replacement materials are low alloy steels containing chromium and molybdenum, with stainless steels containing more chromium dealing with more corrosive environments. More expensive materials commonly used are nickel, titanium, and copper
alloys. These are primarily saved for the most problematic areas where
extremely high temperatures and/or very corrosive chemicals are present.
Corrosion is fought by a complex system of monitoring,
preventative repairs and careful use of materials. Monitoring methods
include both offline checks taken during maintenance and online
monitoring. Offline checks measure corrosion after it has occurred,
telling the engineer when equipment must be replaced based on the
historical information they have collected. This is referred to as
preventative management.
Online systems are a more modern development, and are
revolutionizing the way corrosion is approached. There are several
types of online corrosion monitoring technologies such as linear
polarization resistance, electrochemical noise
and electrical resistance. Online monitoring has generally had slow
reporting rates in the past (minutes or hours) and been limited by
process conditions and sources of error but newer technologies can
report rates up to twice per minute with much higher accuracy (referred
to as real-time monitoring). This allows process engineers to treat
corrosion as another process variable that can be optimized in the
system. Immediate responses to process changes allow the control of
corrosion mechanisms, so they can be minimized while also maximizing
production output.
In an ideal situation having online corrosion information that is
accurate and real-time will allow conditions that cause high corrosion
rates to be identified and reduced. This is known as predictive
management.
Materials methods include selecting the proper material for the
application. In areas of minimal corrosion, cheap materials are
preferable, but when bad corrosion can occur, more expensive but longer
lasting materials should be used. Other materials methods come in the
form of protective barriers between corrosive substances and the
equipment metals. These can be either a lining of refractory material
such as standard Portland cement
or other special acid-resistant cements that are shot onto the inner
surface of the vessel. Also available are thin overlays of more
expensive metals that protect cheaper metal against corrosion without
requiring lots of material.
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