What Goes On In An Oil

Refinery?

----REACTIONS - SEPARATIONS----

Crude Oil is fractionated to usable products

What shall we learn here? Petroleum and natural gas are transported, stored near Refinery, then

What is the Purpose of an Oil Refinery?

What Goes In / Out of the Refinery?

How Do You Get from Crude Oil to Products?

– Separations

– Chemical Reactions cont...

here we shall learn - Cont.

How Do You Get from Crude Oil to

Products?

– Separations

– Chemical Reactions

– Major Equipment

– Minimizing Pollution

What do The Engineers Do?

Refer the following books also

1. Gary, J.H. and Handwerk, G.E “Petroleum Refining Technology and Economics”, 4th edition, Marcel Dekker Inc., New York, 2001.

1. Nelson, W.L. “Petroleum Refinery Engineering”, 4th edition, McGraw-Hill, New York, 1980.

1. Mayers, Robert A., editor “ Handbook of Petroleum Refining Processes”,2nd edition, McGraw-Hill, New York, 1997, 3rd edition,2003.

Overview

THE PURPOSE OF AN OIL REFINERY IS TO TRANSFORM CRUDE OIL INTO USEFUL PRODUCTS AS EFFICIENTLY, PROFITABLY AND ENVIRONMENTALLY SOUND A WAY AS POSSIBLE

Overview - Cont.

The price and quality of crudes are variable. The

price and specifications of the products are to be

maintained. Government regulations add

constraints. There has to be a differential between

the price of crude and products; products are

essential in everyday life. Government subsidies

need to be kept to a minimum.

MY CUSTOMERS KEEP ME IN BUSINESS

How Do I Keep In Business ?

I need to design and erect the plants utilizing

logistics and use efficient technology.

I need to operate (control) the plant in the most

efficient manner possible.

Flow of feedstock to refinery, products to users

need to be done smoothly.

I need to keep the equipment running all the time.

I NEED PLANNERS, ENGINEERS!

OK, But...

WHAT GOES ON IN AN OIL

REFINERY?

Very Simplified

Petroleum and

Petrochemical

Flowchart

Oil

WellCrude

OilSeparations

Co

nve

rsio

ns

Sep

arat

ion

s

and

Pu

rifi

cati

on

s

Natural

Gas

Propane &Butane

Naphtha(C

5 - C

10)

Gas Stove

Fuel

Gasoline

Jet Fuel

Fuel

RX Ethylene Polyethylene (Glad Bags)

RX

RX Polymers (7 UP Bottles) (Barbeque Grills)

RX

RX Organic Chemicals

More Polymers

(Aspirin, Hair Spray)

(Football Helmet, Astro

Turf, Nylon)

Home Heating

Oil, Lubricating

Oil, Wax

Diesel Fuels

Kerosene &

Gas Oils (C10

+)

Coke(Carbon Material Similar to Coal)

Steel Making

AsphaltRoads Pot Holes

Purifications remove sulfur and heavy metals

RX = Chemical Reactions

Graphite Fibers

(Tennis Racquets)

THE REFINERY

Petroleum refining begins with: crude oil distillation,

followed by subsequent processing such as chemical

treating, catalytic reforming, hydrotreating,

hydrocracking, fluid catalytic cracking and thermal

cracking to produce a wide variety of petroleum

products.

The capacity of the refinery is typically defined by the

total capacity of atmospheric distillation units operating

in the refinery.

Fuels (motor gasoline, diesel and distillate

fuel oil, liquefied petroleum gas, jet fuel,

residual fuel oil, kerosene and coke)

Finished nonfuel products (solvents,

lubricating oils, greases, petroleum wax,

petroleum jelly, asphalt, and coke)

Chemical industry feed stocks (naphtha,

ethane, propane, butane, ethylene,

propylene, butylenes, butadiene, benzene,

toluene, and xylene).

The products of the refinery fall into three categories:

No two refineries are identical

Once the refinery is constructed switching to another type

of crude or change of the product distribution (because of

product demand pattern changes or specification

changes or environmental and health regulations) will be

difficult.

Refinery equipment are expensive and long life hence

not easy to replace or modify.

What Is Crude Oil?

Crude Oil is a liquid mixture of many

organic chemicals found underground. It is

the result of organic matter decaying over

thousands of years; hence the name fossil

fuel

Crude oil is found all over the world and

varies tremendously in its density,

aromatics, sulfur, and metals content

Major Refinery Products LPG (Propane/Butane)

GASOLINE (hundreds of blends)

JET FUELS

DIESEL FUELS

LUBRICATING OILS AND GREASES

ASPHALTS

COKE (not the kind you drink )

FEED STOCK FOR CHEMICAL FERTILIZER

MANUFACTURE

FUEL FOR THERMAL POWER PLANTS

Gasoline Specifications

Gasoline (Petrol) must meet many criteria which

change with the time of year and geographic

location. Some critical specifications are:

Vapor Pressure

Octane

Aromatics / Benzene Content

Sulfur Content

Gasoline is always a blend of a number of streams in

the refinery

Other Specifications

Other refinery products must meet other

specifications such as:

Cetane number

Density

Pour Point

Flash Point

Viscosity

So, How Do You Make Good

Stuff Out Of That Gooey Crude?

So, How Do You Make Good

Stuff Out Of That Crude?

So, How Do You Make Good Stuff

Out Of That Crude?

THERMAL, CATALYTIC

REACTIONS

&

PHSICAL SEPARATIONS

Separation based on molecular size and boiling point

Changing the molecular size of components

Changing the molecular shape of components

Removal of contaminants

Processing options

So, How Do You Make Good Stuff Out Of

That Crude?

Separate crude into light, middle and heavy

fractions

Convert low octane components to higher octane

components of petrol.

Blend intermediate streams together to meet

product specifications

Convert the very heavy stuff to heavy oils

Convert heavy oils, recover petrol, diesel, jet fuel

Remove sulfur/nitrogen through reaction

SEPARATIONS

SEPARATIONS - CRUDE FRACTIONATION

HUGE DISTILLATION COLUMNS

– ATMOSPHERIC DISTILLATION

– VACUUM DISTILLATION

TYPICAL SIZE: 150,000 BARRELS/DAY

750 DEGREES F

OTHER SEPARATIONS

FLASH

DISTILLATION

ABSORPTION

ADSORPTION

LIQUID-LIQUID EXTRACTION

REACTIONS

REACTIONS

Almost all the reactions in the refinery use

special catalysts that increase the rate and

selectivity of the reaction. This improves

efficiency and reduces unwanted

byproducts.

Reactions to Make Higher Octane

ISOMERIZATION

C-C-C-C-C-C --> C C

nC6 C-C-C-C iC6

REFORMING

C-C-C-C-C-C-C --> C

nC7 C C-CH3

C C toluene

C

Reactions To Make Higher Octane

ALKYLATION

C C

C=C-C + C-C-C --> C-C-C-C-C

C

propylene isobutane isoheptane (2,2,dmp)

Reactions To Convert Heavy Oils

HYDROCRACKING

H2 + heavy oil --> gasoline + diesel

550 F 300 F 450 F

use boiling point to describe oils

CAT CRACKING

heavy oil --> gasoline + propylene, butane,

other “light ends”

550 F 300 F

Reactions To Convert Residue

Residue is the “bottom of the barrel” - the

material that is left in the bottom of the

crude/vacuum distillation towers

COKING

residue + heat --> coke + heavy oil

> 900 F solid 550 F

Reactions To Remove Sulfur

HYDRODESULFURIZATION

2 R-SH + H2 --> 2 R + 2 H2S

mercaptan hydrocarbon

SULFUR RECOVERY

convert H2S to elemental sulfur: 2 H2S + 2 O2 --> SO2 + S + 2 H2O 2 H2S + SO2 --> 3S + 2 H2O

MAJOR REFINERY EQUIPMENT

Vessels-Reactors, Separators, Storage Tanks

Pumps & Compressors

Furnaces

Heat Exchangers

Instruments (measure flow, temperature,

pressure, composition)

Control Systems

MINIMIZING POLLUTION

Operate Furnaces Efficiently

Waste Material Goes To The Flare Stack

Avoid Spills & Accidental Releases

Special Treatment of Sewer Water

Lots of Paper Work!

Crude oils may contain trace amounts of

metals such as nickel and vanadium, as well

as salts.

Most of the nonhydrogen, non-carbon

elements found in crude oils are undesirable

and are removed from the hydrocarbons in

total or in part during refinery processing.

WHAT ARE THE STUFF REMOVED FROM

THE CRUDE?

Sulfur

– converted to elemental sulfur

– in high sulfur fuel oil

– in coke

Heavy Metals (nickel, vanadium)

– in high sulfur fuel oil and coke

Nitrogen (organic nitrogen)

– most is converted to ammonia and neutralized

– in high sulfur fuel oil and coke

ENGINEERS PLAY AN IMPORTANT

ROLE IN THE REFINERY

What Roles Do Engineers Play?

Operations Engineer

Maintenance Engineer

Control Systems Engineer

Design Engineer

Health/Safety/Environmental Engineer

Planning / Scheduling Engineer

Reliability Engineer

Plant Manager

Other Ways Chemical Engineers

Support The Refining Industry

Research & Development Engineers

Technical Sales Engineers

Engineering & Construction Engineers

Governmental Regulators (EPA)

University Professors

Other Engineering Disciplines In

The Refinery

Mechanical Engineers - design &

maintenance of compressors, vessels …

Electrical Engineers - electrical,

instrumentation, controls

Computer Scientists - main plant control &

information systems

Summary

Refineries are well designed chemical

processing plants that use reactions and

separations to convert crude oil into

gasoline and other valuable products

Chemical engineers play a role in keeping

these plants running safely and efficiently