Introduction to Jurong Island

Up to the 1960s, the southern islands off Jurong, namely Pulau Ayer Chawan, Pulau Ayer Merbau, Pulau Merlimau and Pulau Seraya housed fishing villages.

From 1960 to 1970, three big oil companies planned to house their facilities on the islands. Esso was located on Pulau Ayer Chawan, Singapore Refinery Company on Pulau Merlimau and Mobil Oil on Pulau Pesek.

To increase economic growth, the Government of Singapore decided to enhance the petrochemical industry. By the 1980s, after 10 years of rapid industrialisation, the Singapore

Planning began in 1991 by JTC Corporation (formerly Jurong Town Corporation), while actual land reclamation began in 1995. Jurong Island was officially declared open on 14^th October 2000 by the former Prime Minister, Mr Goh Chok Tong. The original seven islets had a land area of 991 hectares, but after land reclamation, Jurong Island has a total land area of more than 3000 hectares today.

ExxonMobil in the Petrochemical Industry

Why ExxonMobil?

ExxonMobil is one of the leading energy companies in the world. It produces and markets fuels, petrochemicals, and lubricants worldwide, all of which are very important to the world today. Furthermore, ExxonMobil has a production plant situated on Singapore’s very own Jurong Island!

ExxonMobil has invested S$4 billion in an oil refinery plant on Jurong Island. The refining of crude oil is the most basic of all processes, because it separates all the components of crude oil so that they can be used in various other ways in the manufacturing of many products mentioned above.

What is crude oil?

Crude oil is a fossil fuel. It is useful because it contains hydrocarbons, substances that contain hydrogen and carbon atoms. Hydrocarbons can produce a lot of energy when burned, thus making it suitable for providing for energy needs.

Here are some hydrocarbons present in crude oil:

Paraffins or Alkanes

• They have a general formula of C_nH_2n+2
• The molecules are straight- or branched-chain
• They can be in gaseous or liquid state at room temperature depending on the type of molecule

Aromatics

• They have a general formula of C₆H₅ - Y (Y is a longer, straight molecule)
• They have ringed structures with one or more rings
• The rings contain 6 carbon atoms with double and single bonds alternating between the carbon atoms
• They are usually liquids at room temperature

Naphthenes & Cycloalkanes

• They have a general formula of C_nH_2n
• They have ringed structures with one or more rings
• The rings contain single bonds between the carbon atoms
• They are usually liquids at room temperature

The Refining Process

The oil refining process starts with a fractional distillation column. As different hydrocarbons have different boiling points, they can be separated by fractional distillation. The crude oil is heated and the various hydrocarbon chains turn to gaseous state when they reach their respective boiling points! When in gaseous state, the various gases pass into different trays where they are then cooled and condensed back into liquid form, before being further processed. It's that easy!

As you can see, crude oil contains many different products such as:

Petroleum gas

• Petroluem gas is used for heating, cooking and making plastics
• It is made up of small alkanes containing 1 to 4 carbon atoms
• It has a boiling range of below 40 degrees Celsius
• It is often liquified under pressure to create liquefied petroleum gas (LPG)

Naphtha or Ligroin

• This will be further processed to make petrol
• It is a mix of alkanes containing 5 to 9 carbon atoms
• It has a boiling range of 60 to 100 degrees Celsius

Petrol

• Petrol is used as motor fuel
• It is usually in liquid state
• It is a mix of alkanes and cycloalkanes containing 5 to 12 carbon atoms
• It has a boiling range 40 to 205 degrees Celsius

Kerosene

• Kerosene is used as fuel for jet engines and tractors and is also the starting material for making other products
• It is usually in liquid state
• It is a mix of aromatics and alkanes containing 10 to 18 carbons
• It has a boiling range 175 to 325 degrees Celsius

Diesel oil

• It is used for diesel fuel and heating oil and it is also the starting material for making other products
• It is usually in liquid state
• It is made up of alkanes containing 12 or more carbon atoms
• It has a boiling range of 250 to 350 degrees Celsius

Lubricating oil

• It is used for motor oil, grease, other lubricants
• It is usually in liquid state
• It is made up of a long chain (20 to 50 carbon atoms) of alkanes, cycloalkanes and aromatics
• It has a boiling range of 300 to 370 degrees Celsius

Fuel oil

• It is used for industrial fuel and is also the starting material for making other products
• It is usually in liquid state
• It is made up of a long chain (20 to 70 carbon atoms) of alkanes, cycloalkanes and aromatics
• It has a boiling range of 370 to 600 degrees Celsius

Residuals

• They are used to make bitumen, asphalt, tar and waxes, and is also the starting material for making other products
• They are usually in solid state
• They are made up of multiple-ringed compounds with 70 or more carbon atoms
• They have a boiling range of greater than 600 degrees Celsius

Chemical Processing

Once the crude oil has been fractioned, the fractions can be changed into different types by cracking (breaking large hydrocarbons into smaller ones), unification (combining small pieces to make larger hydrocarbons) and alteration (rearranging different pieces to make different hydrocarbons).

Cracking can be done using heat, where the hydrocarbons are heated to very high temperatures until they break apart, or by using a catalyst to speed up the cracking reaction.

Coking, a sub-process of cracking, is where residuals are heated until they crack into heavy oil, petrol and naphtha. A pure carbon residue (coke) is left behind, which is then cleaned and sold.

Unification uses catalytic reforming. A catalyst is used to combine naphtha into aromatics which can then be used in making chemicals and blending petrol.

Alteration uses a process called alkylation. Molecularly light compounds are mixed in the presence of a catalyst to produce high octane hydrocarbons, which are used in petrol blends.

Putting all the processes together in a diagram, we get:

Further Processing of the Fractions

The fractions have to be then treated to remove impurities like organic compounds that contain sulphur, nitrogen, oxygen, water, dissolved metals and inorganic salts. The fractions are passed through either sulphuric acid (to remove unsaturated hydrocarbons with C=C double bonds, nitrogen compounds, oxygen compounds and residuals), an absorption column full of drying agents to remove water, or sulphur treatment and hydrogen sulphide to remove sulphur and other sulphur compounds.

The fractions are then cooled and blended to make products such as petrol with or without additives, lubricating oils and kerosene of varying grades, jet fuel, diesel fuel, heating oil and chemicals of varying grades for making plastics and other polymers, which are used to make plastic bags, toys, diapers and many more products we use every day.

Safety - Environmental & Industrial

Oil refinery releases many chemicals and contaminants into the environment and atmosphere. As a result, the air and water surrounding a refinery plant is likely to get polluted, which is ultimately bad for our health and the environment. Furthermore, there is also the concern of noise pollution as these refinery plants are apt to emit noise levels above the appropriate level for urban places. This air, water and noise pollution can pose health risks for the human population.

As such, oil refineries have to be located away from major urban districts, which is the case of the ExxonMobil plant on Jurong Island, located a safe distance away from the Singapore mainland.

Oil refining is also a very dangerous job because many products are highly flammable, present in very large quantities, and also, many of the refining processes require high temperatures and pressures. This means that there is a high risk of large-scale fires and explosions. Also, many refining processes use toxic and corrosive chemicals, so storage and handling of these chemicals must be done with care. Therefore, these chemicals are contained in closed systems that monitor and control the exposure of the chemicals. Workers are also specially trained in process technology and operation in safe conditions and supervised closely. They are also taught to be prepared for any emergency and be on their toes at all times. Equipment and facilities in the refineries are always carefully maintained. Also, the island is closed to visitors to prevent theft of fuels, which could lead to terror attacks.