Petrochemical plant in the Kingdom of Saudi Arabia

Petrochemicals, also called petroleum distillates, are chemical products derived from petroleum. Some chemical compounds made from petroleum are also obtained from other fossil fuels, such as coal or natural gas, or renewable sources such as corn or sugar cane.

The two most common petrochemical classes are olefins (including ethylene and propylene) and aromatics (including benzene, toluene and xylene isomers). Oil refineries produce olefins and aromatics by fluid catalytic cracking of petroleum fractions. Chemical plants produce olefins by steam cracking of natural gas liquids like ethane and propane. Aromatics are produced by catalytic reforming of naphtha. Olefins and aromatics are the building-blocks for a wide range of materials such as solvents, detergents, and adhesives. Olefins are the basis for polymers and oligomers used in plastics, resins, fibers, elastomers, lubricants, and gels.[1][2]

Global ethylene and propylene production are about 115 million tonnes and 70 million tonnes per annum, respectively. Aromatics production is approximately 70 million tonnes. The largest petrochemical industries are located in the USA and Western Europe; however, major growth in new production capacity is in the Middle East and Asia. There is substantial inter-regional petrochemical trade.

Primary petrochemicals are divided into three groups depending on their chemical structure:

The prefix "petro-" is an arbitrary abbreviation of the word "petroleum"; since "petro-" is Ancient Greek for "rock" and "oleum" means "oil". Therefore, the etymologically correct term would be "oleochemicals". However, the term oleochemical is used to describe chemicals derived from plant and animal fats.



Petrochemical feedstock sources

The adjacent diagram schematically depicts the major hydrocarbon sources used in producing petrochemicals are:[1][2][3][4]

Methane and BTX are used directly as feedstocks for producing petrochemicals. However, the ethane, propane, butanes, naphtha and gas oil serve as optional feedstocks for steam-assisted thermal cracking plants referred to as steam crackers that produce these intermediate petrochemical feedstocks:

  • Ethylene
  • Propylene
  • Butenes and butadiene
  • Benzene

In 2007, the amounts of ethylene and propylene produced in steam crackers were about 115 Mt (megatonnes) and 70 Mt, respectively.[5] The output ethylene capacity of large steam crackers ranged up to as much as 1.0 – 1.5 Mt per year.[6]

Steam crackers are not to be confused with steam reforming plants used to produce hydrogen and ammonia.

Manufacturing locationsEdit

Like commodity chemicals, petrochemicals are made on a very large scale. Petrochemical manufacturing units differ from commodity chemical plants in that they often produce a number of related products. Compare this with specialty chemical and fine chemical manufacture where products are made in discrete batch processes.

Petrochemicals are predominantly made in a few manufacturing locations around the world, for example in Jubail & Yanbu Industrial Cities in Sauid Arabia, Texas & Louisiana in the USA, in Teesside in the Northeast of England in the United Kingdom, in Rotterdam in the Netherlands, and in Jamnagar & Dahej in Gujarat, India. Not all of the petrochemical or commodity chemical materials produced by the chemical industry are made in one single location but groups of related materials are often made in adjacent manufacturing plants to induce industrial symbiosis as well as material and utility efficiency and other economies of scale. This is known in chemical engineering terminology as integrated manufacturing. Speciality and fine chemical companies are sometimes found in similar manufacturing locations as petrochemicals but, in most cases, they do not need the same level of large scale infrastructure (e.g., pipelines, storage, ports and power, etc.) and therefore can be found in multi-sector business parks.

The large scale petrochemical manufacturing locations have clusters of manufacturing units that share utilities and large scale infrastructure such as power stations, storage tanks, port facilities, road and rail terminals. In the United Kingdom for example, there are 4 main locations for such manufacturing: near the River Mersey in Northwest England, on the Humber on the East coast of Yorkshire, in Grangemouth near the Firth of Forth in Scotland and in Teesside as part of the Northeast of England Process Industry Cluster (NEPIC). To demonstrate the clustering and integration, some 50% of the United Kingdom's petrochemical and commodity chemicals are produced by the NEPIC industry cluster companies in Teesside.

List of significant petrochemicals and their derivativesEdit

The following is a partial list of the major commercial petrochemicals and their derivatives:

Chemicals produced from ethylene
Chemicals produced from propylene
Chemicals produced from benzene
Chemicals produced from toluene
Chemicals produced from xylenes

Petrochemicals productsEdit

Petrochemicals Fibers Petroleum Chemicals
Basic Feedstock

2-Ethylhexanol (2-EH)
Acetic acid
Acrylonitrile (AN)
Bis(2-ethylhexyl) phthalate (dioctyl phthalate)
Dimethyl terephthalate (DMT)
1,2-Dichloroethane (ethylene dichloride or EDC)
Ethylene glycol (EG)
Ethylene oxide (EO)
Formaldehyde Moulding Compound (FMC)
Linear alkyl benzene (LAB)
Methyl tert-butyl ether (MTBE)
Propylene oxide
Purified terephthalic acid (PTA)
Styrene monomer (SM)
Thermosetting Resin (Urea/Melamine)
Vinyl acetate monomer (VAM)
Vinyl chloride monomer (VCM)

Acrylic fiber
Acrylonitrile butadiene styrene (ABS)
Acrylonitrile styrene (AS)
Polybutadiene (PBR)
Polyvinyl chloride (PVC)
Polyethylene (PE)
Polyethylene terephthalate (PET)
Polypropylene (PP)
Polystyrene (PS)
Styrene butadiene (SBR)
Acrylic-formaldehude (AF)
Marine fuel oil
Petroleum refining
Adhesives and sealants
Construction chemicals
Corrosion control chemicals
Cosmetics raw materials
Electronic chemicals and materials
Flavourings, fragrances, food additives
Pharmaceutical drugs
Specialty and industrial chemicals
Specialty and industrial gases
Inks, dyes and printing supplies
Packaging, bottles, and containers
Paint, coatings, and resins
Polymer additives
Specialty and life sciences chemicals
Surfactants and cleaning agents

See alsoEdit


  1. ^ a b Sami Matar and Lewis F. Hatch (2001). Chemistry of Petrochemical Processes. Gulf Professional Publishing. ISBN 0-88415-315-0. 
  2. ^ a b Staff (March 2001). "Petrochemical Processes 2001". Hydrocarbon Processing: 71–246. ISSN 0887-0284. 
  3. ^ SBS Polymer Supply Outlook
  4. ^ Jean-Pierre Favennec (Editor) (2001). Petroleum Refining: Refinery Operation and Management. Editions Technip. ISBN 2-7108-0801-3. 
  5. ^ Hassan E. Alfadala, G.V. Rex Reklaitis and Mahmoud M. El-Halwagi (Editors) (2009). Proceedings of the 1st Annual Gas Processing Symposium, Volume 1: January, 2009 - Qatar (1st ed.). Elsevier Science. pp. 402–414. ISBN 0-444-53292-7. 
  6. ^ Steam Cracking: Ethylene Production (PDF page 3 of 12 pages)

External linksEdit

  Media related to Petrochemicals at Wikimedia Commons