CRACKING OF PETROLEUM

SUBMITTED TO

EGNR. ONYENANU & ENGR. CHINYELU

OF

THE DEPARTMENT OF CHEMICAL ENGINEERING

FACULTY OF ENGINEERING

NNAMDI AZIKIWE UNIVERSITY, AWKA

IN PARTIAL FULFILMENT OF THE REQUIREMENT OF THE COURSE

PETROLEUM REFINNING PROCESSES (ChE 586)

BY

GROUP E

OBIEFUNA KINGSLEY TOCHUKWU 2018214007

CHIKEZIE PRECIOUS CHIBUEZE 2018214015

ONWUGHARA CHARLES IZUCHUKWU 2015214065

OKEKE FLORENCE IFEYINWA 2018214006

ORAGUI DANIEL UGOCHUKWU 2018214017

NOVEMBER 30, 2023

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 Table of Contents

WHAT IS PETROLEUM? .....................................................................................1

Refining of Petroleum ........................................................................................1

Distillation in Petroleum Refining .....................................................................2

Limitation of Distillation in Petroleum Refining...............................................3

Why Cracking is Required .................................................................................3

OVERVIEW OF CRACKING PROCESS ............................................................4

History and Development of Cracking ..............................................................6

CRACKING PROCESS ........................................................................................7

Thermal Cracking ..............................................................................................7

Catalytic Cracking............................................................................................18

Pyrolysis ...........................................................................................................23

REFERENCES.....................................................................................................25

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WHAT IS PETROLEUM?

Petroleum, also called crude oil, is a naturally occurring liquid found beneath the
earth’s surface that can be refined into fuel. A fossil fuel, petroleum is created by the
decomposition of organic matter over long period of time, and can be extracted to
be used to power vehicles, heating units, and machine, and can be converted into
plastics. Petroleum is gotten from the Latin word “Petra” meaning “rock,” and
“oleum” meaning “oil.” It consists of hydrocarbons of various molecular weights
and other organic compounds. Majority of the world relies on petroleum for many
goods and services. This has made the petroleum industry a major influence on world
politics and the global economy. Petroleum is recovered from underneath the earth
surface by drilling and then refined and separated into different types of fuels of
differing molecular weights and varying compositions. Key components of
petroleum include hydrocarbons such as methane, ethane, propane, and complex
molecules like benzene. After extraction, crude oil undergoes refining processes to
separate and purify its components, yielding products like gasoline, diesel, jet fuel,
and petrochemicals.

Refining of Petroleum
Petroleum refining is a complex industrial process that transforms crude oil into a
variety of valuable products, meeting market demands and regulatory standards.
Petroleum refining begins with the distillation, or fractionation, of crude oils into
separate hydrocarbon groups. The resultant products are directly related to the
characteristics of the crude processed. Most distillation products are further
converted into more usable products by changing the size and structure of the
hydrocarbon molecules through cracking, reforming, and other conversion
processes.

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Distillation in Petroleum Refining
Distillation, being the fundamental step in petroleum refining, serves as the initial
separation process to obtain various hydrocarbon fractions from crude oil. The
process begins with the crude oil feedstock, a mixture of hydrocarbons obtained
from beneath the earth’s surface. The crude oil is pretreated to a high temperature to
facilitate ease in distillation. After pretreatment, the crude in introduced into a
distillation tower, also known as crude unit, where the crude undergoes fractionation
into different components based on their boiling points. As the crude moves up the
tower, it encounters decreasing pressure, causing it to vaporize. The hydrocarbons
vaporize at different heights within the tower. The vaporized hydrocarbons rise
through the tower and are condensed back into liquid form as the meet cooler
temperatures at higher levels of tower or a passed through a condenser.

Fig 1 Process flow diagram for Atmospheric distillation of crude oil

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Different fractions are collected at different levels of the tower. Lighter components,
such as gases and naphtha, are collected at the top, while heavier components, like
diesel and lubricating oils, are collected at lower level. The heaviest component that
does not vaporize effectively remain as residue at the bottom of the tower. This
residue may undergo further processing. The separated fractions are cooled and then
stored for further processing or distribution, or as a feedstock for subsequent refining
processes such as cracking, desulfurization, and other treatments to produce specific
refined products.

Limitation of Distillation in Petroleum Refining

Despite distillation being the fundamental step in the refining process, there are
various limitations to it. Some of these limitations include;

1. Temperature Sensitivity: Distillation relies on boiling point differences, and

some hydrocarbons have close boiling points. This makes it difficult to
separate components effectively.
2. Incomplete Separation: It is very difficult to obtain complete separation of
all components using distillation. Certain fractions may contain a mixture of
hydrocarbons.
3. Heavy Residues: Distillation leaves behind heavy residues that contain high
molecular weight compounds. These residues are less valuable and may often
times require further processing.
4. Limited Yield of High-Value Products: Distillation tends to produce a
significant amount of lower-value products, such as heavy oils, which may
have limited market demand.

Why Cracking is Required

Due to the limitations on distillation of petroleum, cracking is required for the
following reasons.
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 1. Conversion of Heavy Fractions: Cracking is required to break down heavier
and less valuable hydrocarbons into lighter, more valuable products like
gasoline and diesel.
2. Maximizing Yield of Valuable Products: Cracking increases the yield of
high-demand products by converting large, less useful hydrocarbons to
smaller and valuable ones.
3. Octane Improvement: Catalytic cracking, in particular, helps improve the
octane number of gasolines by producing branched and cyclic hydrocarbons.
Octane number in of itself is a standard measure of a fuel’s ability to withstand
compression in an internal combustion engine without detonating.
4. Adaptation to Market Demands: Cracking allows refineries to adapt to
changing market demands. As the demand of gasoline increases, refineries can
adjust the cracking processes to produce a more gasoline component.
5. Removal of Impurities: Cracking processes, like hydrocracking, often
involve the removal of impurities such as sulfur, which is crucial for meeting
environmental standards.

OVERVIEW OF CRACKING PROCESS

Cracking is a conversion process which involves the breaking down of long and
heavy hydrocarbon molecules to simpler ones by the action of heat, catalyst or both.
It is a process whereby complex organic molecules such as kerogens or long-chain
hydrocarbons are broken down into simpler molecules such as light hydrocarbons,
by the breaking of carbon-carbon bonds in the precursors.

The rate of cracking and the end products are strongly dependent on
the temperature and presence of catalysts. Cracking is the breakdown of a
large hydrocarbons into smaller, more useful alkanes and alkenes. Simply put,
hydrocarbon cracking is the process of breaking a long chain of hydrocarbons into

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short ones. This process requires high temperatures More loosely, outside the field
of petroleum chemistry, the term "cracking" is used to describe any type of splitting
of molecules under the influence of heat, catalysts and solvents, such as in processes
of destructive distillation or pyrolysis. Fluid catalytic cracking produces a high yield
of petrol and LPG, while hydrocracking is a major source of jet fuel, diesel
fuel, naphtha, and again yields LPG.

During cracking, hydrocarbon molecule, CnH2n +2 with n (i.e. number of carbon

atoms) greater than 25 splits into two, almost at the middle, giving a saturated
molecule and another unsaturated molecule. All cracking reactions ultimately give
rise to coke and hydrogen. During this process, it involves numerous chemical
reactions based on free radicals. Some vital reactions that take place are stated below.

• Initiation: Here a single molecule breaks down into 2 free radicals. Only a
smaller portion of freed radicals undergoes initiation, but it is sufficient to
produce free radicals that are necessary to carry forward the reaction.
CH3CH3 → 2CH3
• Abstraction of Hydrogen: Here the second molecules become a free radical
as it removes a hydrogen atom from another molecule
CH3● + CH3CH3 → CH4 + CH3CH2●
• Radical Decomposition: Here free radicals break into other free radical and
an alkane. This reaction gives rise to alkene products.
CH3CH2● → CH2=CH2 + N
• Radical Addition: This reaction results in the formation of aromatic products.
Here radical reacts with an alkene to produce a free radical.
CH3CH2● + CH2=CH2 → CH3CH2CH2CH2●

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 • Termination: Here 2 radicals react with each other to form products that are
not free radicals. This reaction results in two forms namely recombination and
disproportionation.
CH3● + CH3CH2● → CH3CH2CH3
CH3CH2● + CH3CH2● → CH2=CH2 + CH3CH3

History and Development of Cracking

The first thermal cracking method known as the Shukhov cracking process was

invented by the Russian engineer Vladimir Shukhov in 1891. It was developed

further in 1913 by William Merriam Burton, a chemist who worked for the Standard

Oil Company (Indiana), which later became the Amoco Corporation. Burton used

the process to break up large nonvolatile hydrocarbons into gasoline. Various

improvements to thermal cracking were introduced into the 1920s. Also in the 1920s,

French chemist Eugène Houdry improved the cracking process with catalysts to

obtain a higher-octane product. His process was introduced in 1936 by the Socony-

Vacuum Oil Company (later Mobil Oil Corporation) and in 1937 by the Sun Oil

Company (later Sunoco, Inc.). Catalytic cracking was itself improved in the 1940s

with the use of fluidized or moving beds of powdered catalyst. During the 1950s, as

demand for automobile and jet fuel increased, hydrocracking was applied to

petroleum refining. This process employs hydrogen gas to improve the hydrogen-

carbon ratio in the cracked molecules and to arrive at a broader range of end

products, such as gasoline, kerosene (used in jet fuel), and diesel fuel. Modern low-

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temperature hydrocracking was put into commercial production in 1963 by the

Standard Oil Company of California (later the Chevron Corporation).

CRACKING PROCESS

The cracking process is very important for the commercial production of light fuels

such as gasoline, fuel oil, and gas oils. Because the simple distillation of crude oil

produces amounts and types of products that are not consistent with those required

by the marketplace, subsequent refinery processes change the product mix by

altering the molecular structure of the hydrocarbons. One of the ways of

accomplishing this change is through cracking. There are two main cracking

processes used in the petroleum sector. They are:

1. Thermal cracking

2. Catalytic cracking

Thermal Cracking

Thermal cracking is a crucial process in the petroleum industry. It allows for the

efficient production of useful products such as gasoline, diesel fuel, and jet fuel from

heavier hydrocarbons. It involves the use of high temperatures (typically in the

range of 450 °C to 750 °C) and pressures (up to about 70 atmospheres) to break the

large hydrocarbons into smaller ones. Thermal cracking gives mixtures of products

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containing high proportions of hydrocarbons with double bonds - alkenes. Some

application of thermal cracking include:

Visbreaking

Fig 2 Process flow diagram of visbreaking unit

Visbreaking (means viscosity breaking) is a mild form of thermal cracking which

significantly lowers the viscosity of heavy crude-oil residue without affecting the

boiling point range. The conversion of the residues is achieved by heating the residue

feedstock at high temperatures in a furnace (800°-950° F). The process fluid is

passed through a soaking zone, located either in the furnace or in an external drum,

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under controlled temperature and pressure. The heater effluent is then quenched with

a quenching medium (usually gas oil) to stop the reaction and control overcracking.

Atmospheric vacuum residues and Solvent Deasphalter bottoms are typical feeds of

the Visbreaking unit which transforms the feed to gas, gasoline, gas oil, and

Visbroken bottom residue depending on the process severity and feedstock

characteristics. It is one of the not very popular in the petroleum refineries compared

to other conversion techniques.

Product stability of the visbreaker residue is the main concern in selecting the

severity of the visbreaker operating conditions. Increasing visbreaking will initially

lead to a reduction in the visbroken fuel oil viscosity. However, fuel oil stability will

decrease as the level of severity increases beyond a certain point.

Types of Visbreaking Processes

There are two types of visbreakers;

1. Coil Visbreaking process

2. Soak visbreaking process

Coil Visbreaking Process

The Coil Visbreaking process achieves conversion by high-temperature cracking

within a dedicated soaking coil in the furnace. Coil visbreaking is described as a

high-temperature, short-residence-time conversion process.Heating of the material

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to predetermined heater outlet temperatures and rapid quenching of furnace outlets

facilitates the thermal cracking and altered viscosity necessary for further

processing. The feedstock is introduced into the heated coil in the furnace and

slightly cracked. Reaction temperatures range from 450 to 495 °C while working

pressures range from 3 to 20 bar.

Fig 3 Coil Type Visbreaking Process

After exiting from the furnace, the visbroken products are quickly quenched to stop

the cracking reactions. To avoid coking in the fractionation tower, the quenching

phase is crucial. The most frequent quenching streams are gas oil and Visbreaker

residue. After quenching, the effluent is transferred to the fractionator’s lower

section, where it is flashed. The fractionator separates the yield into gas, gasoline,

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gas oil, and Visbreaker tar (residue). The fractionated gas oil is steam stripped to

remove volatile components before being mixed with the Visbreaker bottoms or

routed for further processing, such as hydrotreating, catalytic cracking, or

hydrocracking.

The main advantage of the coil-type design is the two-zone fired heater. This type of

heater provides a high degree of flexibility in heat input, resulting in better control

of the material being heated. With the coil-type design, decoking of the heater tubes

is accomplished more easily by the use of steam-air decoking.

Soaker Visbreaking Process

The soaker-type Visbreaking process is very similar to the coil-type process except

the conversion is proceeded mainly in a vessel called Soaker after the heater. It

achieves some conversion within the heater. However, the majority of the conversion

occurs in a reaction vessel or soaker which holds the two-phase effluent at an

elevated temperature for a predetermined length of time. Soaker visbreaking is

described as a low-temperature, high-residence-time route.

The soaker drum design allows the heater to operate at a lower outlet temperature

by providing the residence time required to achieve the desired cracking reactions.

This lower heater outlet temperature results in lower fuel cost which is the advantage

over the coil-type visbreaking process. The basic configuration of the Soaker Process

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includes the heater, soaker, and fractionators, and a vacuum tower can also be applied

to recover more distillate products.

Fig 4 Soaker Visbreaking Process

Soaker cracking often involves less capital investment, uses less energy, and has

longer on-stream durations. Product qualities and yields from the coil and soaker

drum design are essentially the same at a given severity and are independent of the

visbreaker configuration.

Steam Cracking

In steam cracking, a gaseous or liquid hydrocarbon feed like naphtha, LPG,

or ethane is diluted with steam and briefly heated in a furnace in the absence of

oxygen. Typically, the reaction temperature is very high, at around 850 °C. The

reaction occurs rapidly with the residence time of the order of milliseconds and flow

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rates approaching the speed of sound. After the cracking temperature has been

reached, the gas is quickly quenched to stop the reaction in a transfer line heat

exchanger or inside a quenching header using quench oil.

Fig 5 Typical Steam Cracking Process

The products produced in the reaction depend on the composition of the feed, the

hydrocarbon-to-steam ratio, and on the cracking temperature and furnace residence

time. Light hydrocarbon feeds such as ethane, LPGs, or light naphtha give mainly

lighter alkenes, including ethylene, propylene, and butadiene. Heavier hydrocarbon

feeds give some of the same products, but also those rich in aromatic

hydrocarbons and hydrocarbons suitable for inclusion in gasoline or fuel oil.

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A higher cracking temperature (severity) favors the production

of ethene and benzene, whereas lower severity produces higher amounts of propene,

butene and liquid products. The process also results in the slow deposition of coke,

a form of carbon, on the reactor walls. This degrades the efficiency of the reactor, so

reaction conditions are designed to minimize this. Nonetheless, a steam cracking

furnace can usually only run for a few months at a time between de-coking’s.

Decoking requires the furnace to be isolated from the process and then a flow of

steam or a steam/air mixture is passed through the furnace coils. This converts the

hard solid carbon layer to carbon monoxide and carbon dioxide. Once this reaction

is complete, the furnace can be returned to service.

Coking

Coking is a severe method of thermal cracking used to upgrade heavy residuals into

lighter products or distillates. It is often considered to be the last stage in the refining

process since the heaviest fractions (tar) are converted into very useful products such

as straight-run gasoline (coker naphtha) and various middle-distillate fractions used

as catalytic cracking feedstock. The process so completely reduces hydrogen that the

residue is a form of carbon called “coke.”

Types of Coking Processes

Different types of coking processes exist but the two most common processes are:

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 1. Delayed coking

2. Fluid (contact or continuous) coking.

Delayed Coking

The process includes a fractionator, furnace, two coke drums, and stripper. the

feedstock is charged directly to the fractionator, where it is heated, and the lighter

fractions are removed as middle distillates. The bottom of the fractionator is pumped

to the coking furnace and then heated to the temperature range of 485–500°C. The

heated feedstock enters one of the pairs of coking drums, where the cracking

reactions continue. The energy obtained in the furnace passages is sufficient to

perform the cracking reaction when the coking drum is filled. In the furnace, steam

is injected to prevent the formation of premature coking. In addition, to prevent the

formation of coke in the furnace, short residence time and high mass velocity in the

furnace are required. Overhead stream in the coking drum, gases, naphtha, middle

distillates and coker heavy gas oil are sent to the fractionator for separation, then

separated and sent to downstream units for post-treatment and coke deposits on the

inner surface. For continuous operation, two coke drums are used; while one is

onstream, the other is decoking. The temperature in the coke drum ranges from 415

to 465°C and the pressure varies between 2 and 6 bar. Coker heavy gas oil is recycled

as a coker feed and combined with fresh preheated feed and fed to the furnace, or

used in other refining processes such as hydrocracker or gas oil hydrotreater or as a

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catalytic fluid cracking feed. The Coke drum is usually onstream about 24 hours

before filling with porous coke.

Fig 6 Schematic of Delayed Coking Process

Fluid Coking

Fluid coking is a thermal cracking process consisting of a fluidized bed reactor and

a fluidized bed burner. Vacuum residue is preheated and fed to a scrubber that

operates at 370°C. It is then injected through nozzles to a fluidized bed of coke

particles. Cracking reactions take place in the reactor at a temperature of 500–550°C,

and the feed is converted to vapour and lighter gases, which enter the scrubber after

passing through the cyclones at the top of the reactor. From the scrubber, the reactor

16
products are sent to the fractionator. Steam enters from the bottom of the reactor to

remove heavy hydrocarbons from the coke surface. The evolution of vapour from

the cracking of the feed, and the addition of steam, gives intense mixing of the coke

particles within the reactor. The coke formed in the reactor flows continuously to the

burner, where it is heated to 593–677°C and burns with partial combustion of 15–

30% of the coke by injecting air into the burner. Coke combustion produces flue

gases with low heating value which are rich in carbon monoxide. Parts of the heated

coke particles are returned to the reactor to provide energy for the endothermic

cracking reactions and to maintain the reactor temperature. After cooling, the

remaining coke is removed from the process as a stream of fine particles of

‘petroleum coke’ and is burned in power plants or cement industries. This coke is

very isotropic, rich in ash and sulphur and therefore not used in the carbon and

graphite industry.

The lower limit on operating temperature for fluid coking is set by the behaviour of

the fluidized coke particles. If the conversion to coke and light ends is too slow, then

the coke particles become sticky and agglomerate within the reactor. This

phenomenon occurs in localised zones of the reactor, likely near the nozzles that

inject the (colder) liquid bitumen feed, giving rise to chunks of coke that fall to the

bottom of the bed. For this reason, optimising the method for introducing feed into

the reactor is crucial. This process generally yields less coke and more gas oil and

17
olefins compared to the delayed coking process. One disadvantage of the fluid

coking process is the high rate of coke accumulation inside the unit. The reactor

operates in a fouling mode, so coke deposits continuously on the interior surfaces

during operation. The reactor must be shut down for a month or more every 2 or 3

years to remove the accumulated coke, which can grow to be as thick as 1 meter on

the interior walls of the coker. The second disadvantage is the emission of significant

amounts of hydrogen sulphide and sulphur dioxide from the reactor burner.

Fig 7 Schematic of Fluid Coking Process

Catalytic Cracking

Catalytic cracking is similar to thermal cracking except that catalysts facilitate the

conversion of the heavier molecules into lighter products. Use of a catalyst (a

material that assists a chemical reaction but does not take part in it) in the cracking

reaction increases the yield of improved-quality products under much less severe

18
operating conditions than in thermal cracking. Typical temperatures are from 850°-

950° F at much lower pressures of 10-20 psi. The catalysts used in refinery cracking

units are typically solid materials such as zeolite, aluminum hydrosilicate, treated

bentonite clay, fuller’s earth, bauxite, and silica-alumina. They are used in the form

of powders, beads, pellets or shaped materials called extrudites.

Some common types of catalytic cracking processes are:

Fluid Catalytic Cracking (FCC)

This process is used in petroleum refineries to convert the low-value heavier long-

chain hydrocarbon refinery fractions such as heavy vacuum gas oils into greater

economic value lighter products, mainly gasoline, distillate, and LPG. The rapid

cracking reactions of the FCC unit depend upon the circulating or fluidization of a

powder zeolite catalyst with the liquid feed into a riser of the FCC reactor for a few

seconds. This unit is normally, installed to produce more gasoline with high octane

rating over residual fuel oil.

There are various amounts of contaminants present in the FCC feed such as sulfur,

nitrogen, conradson carbon residue (CCR), and metals, particularly in high boiling

fractions. These impurities have negative effects on the unit performance.

Hydrotreating significantly improves the properties of the FCC feeds through

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Hydrodesulfurization, Hydrodenitrogenation, Hydrodemetallization, Aromatic

saturation, and conradson carbon removal.

Fig 8 Schematic of Fluid Catalytic Cracking Process

The FCC feed is heated up to a temperature of about 315~425oC and mixed with hot

regenerated catalyst (640~760 oC) at the bottom of the riser, which is a long vertical

pipe. The liquid feed is vaporized due to the hot catalyst and goes up in the riser for

a short period of 2~10 seconds.

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The temperature at the riser outlet is a key factor in determining conversion and

product quality. At the top of the riser, the temperature reaches nearly 550 oC. The

riser is the main reactor in which the endothermic reactions take place. High

temperature favors the production of olefin-rich light gases at the expense of

gasoline, moderate temperature favors the production of gasoline, and lower

temperature increases the distillate yields.

From the top of the riser, the gaseous products flow into the fractionator column,

while the separated catalyst and some heavy liquid hydrocarbons flow back into the

disengaging zone of the FCC reactor. Steam is also injected into the stripper section

to remove the oil from the spent catalyst. The oil is stripped from the catalyst and

moves along with rising vapors to the fractionator. The spent catalyst is sent to the

regenerator at a temperature of 475–550 oC.

The coke on the spent catalyst, produced in the FCC cracking reactions, is burned

off in the regenerator by introducing air. The produced hot flue gases exit at the top

of the regenerator that contains carbon dioxide, carbon monoxide, water, and excess

air at the regenerator temperature. The flue gases can also be sent to the power

recovery unit to produce superheated steam.

The FCC unit operation remains at a steady state as long as a heat balance exists

between the heat produced in the regenerator and the heat consumed in the reactor.

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In both the reactor and the regenerator, hydro cyclones are installed to remove any

solid catalyst particles carried out in the overheated gaseous stream.

Hydro Catalytic Cracking

A hydrocracking unit, takes gas oil which is heavier and has a higher boiling range

than distillate fuel oil, and cracks the heavy molecules into distillate and gasoline in

the presence of hydrogen and a catalyst. The hydrocracker upgrades low-quality

heavy gas oils from the atmospheric or vacuum distillation tower, the fluid catalytic

cracker, and the coking units into high-quality, clean-burning jet fuel, diesel, and

gasoline.

Fig 9 Block Flow Diagram of the Hydrocracking process

There are two main chemical reactions occurring in the hydrocracker: catalytic

cracking of heavy hydrocarbons into lighter unsaturated hydrocarbons and the

22
saturation of these newly formed hydrocarbons with hydrogen. The catalytic

cracking of the heavier hydrocarbons uses heat and causes the feed to be cooled as

it progresses through the reactor. The saturation of the lighter hydrocarbons releases

heat and causes the feed and products to heat up as they proceed through the reactor.

Hydrogen is also used to control the temperature of the reactor—it is fed into the

reactor at different points. This keeps the reactor temperature from cooling to the

point that cracking will not occur and from rising too high as to jeopardize the safety

of the operation

Pyrolysis

Pyrolysis is the converting of compounds into smaller fragments in the absence of

air with the application of heat. Pyrolysis of higher alkanes to produce a mixture of

lower alkanes and alkenes are referred to as cracking. Usually, it is carried out by

heating the higher alkanes to high temperatures (670K – 970K) under pressure

ranging from 6-7 atm, either in the presence or absence of a catalyst. The chemical

reaction for the same can be given as follows:

C6H14 → C6H12 + H2 + C4H8 + C2H6 + C3H6 + C2H4 + CH4

When alkane vapors are passed in the absence of air through red-hot metal, it breaks

down into smaller or simpler hydrocarbons. This specific process occurs at high

pressure and high temperatures without a catalyst. But can be carried out at lowed

23
pressures and temperatures in the presence of a catalyst such as palladium or

platinum.

Pyrolysis can be used to extract materials from items like tires or remove organic

contaminants from oily sludges and soils, and make biofuel from crops and waste.

It can assist in the breakdown of vehicle tires into some useful components on the

other hand also reducing the environmental impact of disposal of tires. Simply put,

cracking is the result of a pyrolysis treatment to hydrocarbon feedstock in that all

cracking operations are essentially pyrolysis but not all pyrolysis operations are

cracking operations.

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REFERENCES

1. Springer Handbook of Petroleum Technology Hsu Robinson (Editors).

2. Fundamentals of Petroleum Refinery by M.A Fahim.

3. Handbook of Petroleum Processing, 2nd Edition by Steven A. Treese, Peter

R. Pujado, David S. J. Jones.

4. Handbook of Petroleum Refining by James G. Speight

5. Bagheri SR. Mesophase Formation in Heavy Oil [thesis]. Edmonton:

University of Alberta; 2012

6. Sahu R, Song BJ, Im JS. A review of recent advances in catalytic

hydrocracking of heavy residues. Journal of Industrial and Engineering

Chemistry. 2015;27:12-24. DOI: 10.1016/j.jiec.2015.01.011

7. Hashemi R, Nassar NN, Almao PP. Nanoparticle technology for heavy oil in-

situ upgrading and recovery enhancement: Opportunities and challenges.

Applied Energy. 2014;133:374-387. DOI: 10.1016/j.apenergy.2014.07.069

8. Nguyen MT, Nguyen NT, Cho J. A review on the oil-soluble dispersed catalyst

for slurry-phase hydrocracking of heavy oil. Journal of Industrial and

Engineering Chemistry. 2016;43:1-12. DOI: 10.1016/j.jiec.2016.07.057

9. Eshraghian A. Thermal and Catalytic Cracking of Athabasca VR and Bitumen

[thesis]. Calgary: University of Calgary; 2017

25
10.Sawarkar AN, Pandit AB, Samant SD. Petroleum residue upgrading via

delayed coking. The Canadian Journal of Chemical Engineering. 2007;85:1-

24. DOI: 10.1002/cjce.5450850101

11.DSJ J, Pujadó PP, editors. Handbook of Petroleum Processing. 1st ed.

Dordrecht: Springer; 2006. p. 1353. DOI: 10.1007/1-4020-2820-2

12.Rana MS, Sámano V, Ancheyta J. A review of recent advances on process

technologies for upgrading of heavy oils and residua. Fuel. 2007;86:1216-

1231. DOI: 10.1016/j.fuel.2006.08.004

13.Castañeda LC, Muñoz JAD, Ancheyta J. Combined process schemes for

upgrading of heavy petroleum. Fuel. 2012;100:110-127. DOI:

10.1016/j.fuel.2012.02.022

14.Prajapati R, Kohli K, Maity SK. Slurry phase hydrocracking of heavy oil and

residue to produce lighter fuels: An experimental review. Fuel.

2021;288:119686. DOI: 10.1016/j.fuel.2020.119686

15.Tsujino T. Recent development of Texaco gasification technology and its

applications. Fuel and Energy Abstracts. 1996;37:183. DOI: 10.1016/0140-

6701(96)88538-9

16.Jaeger H, Frohs W, editors. Industrial Carbon and Graphite Materials: Raw

Materials, Production and Application. 1st ed. Weinheim: Wiley; 2021. p.

1008 ISBN: 9783527336036

26
17.Gray MR. Upgrading Oilsands Bitumen and Heavy Oil. 1st ed. Edmonton:

The University of Alberta Press; 2015. p. 499 ISBN: 9781772120356

18.Fahim MA, Al-Sahhaf TA, Elkilani AS. Fundamentals of Petroleum Refining.

1st ed. Oxford: Elsevier; 2010. p. 516 ISBN: 9780444527851

19.Huc AY. Heavy Crude Oils: From Geology to Upgrading: An Overview. 1st

ed. Paris: IFP energies nouvelles publications; 2011. p. 516 ISBN:

9782710808909

20.Speight JG. Heavy oil Recovery and Upgrading. 1st ed. Cambridge: Gulf

professional publishing; 2019. p. 850 ISBN: 9780128130254

21.Speight JG. Heavy Oil and Extra-Heavy Oil Upgrading Technologies. 1st ed.

Oxford: Gulf professional publishing; 2013. p. 176 ISBN: 9780124045705

22.Clark JG. The Modification of Waxy Oil for Preparing a Potential Feedstock

for Needle Coke Production [thesis]. Pretoria: University of Pretoria; 2011

23.Edwards L. The history and future challenges of calcined petroleum coke

production and use in aluminum smelting. Journal of Metals. 2015;67:308-

321. DOI: 10.1007/s11837-014-1248-9

24.Vieman AA. The Impact of Phase Behaviour on Coke Formation in Delayed

Cokers [thesis]. Toronto: University Toronto; 2002

27
25.Escallón MM. Petroleum and Petroleum/Coal Blends as Feedstocks in

Laboratory-Scale and Pilot-Scale Cokers to Obtain Carbons of Potentially

High Value [thesis]. Pennsylvania: The Pennsylvania State University; 2008

26.Zhu H, Zhu Y, Xu Y. Transformation of microstructure of coal-based and

petroleum-based needle coke: Effects of calcination temperature. Asia-Pacific

Journal of Chemical Engineering. 2021;16. DOI: 10.1002/apj.2674

27.Wang G. Molecular Composition of Needle Coke Feedstocks and Mesophase

Development during Carbonization [thesis]. Pennsylvania: The Pennsylvania

State University; 2005

28