Shell chemicals companies are among the leading global producers of lower olefins - including ethylene, propylene, butadiene and isoprene - with world-scale production facilities in North America, Europe and Asia Pacific. Along with aromatics, lower olefins provide the basic building blocks of the modern petrochemical industry and without them our cars, homes, work places and schools would look very different.
Lower olefins are produced directly by the high temperature ‘cracking’ of hydrocarbons such as naphtha and gas oil in the presence of steam, or indirectly through extraction or separation from cracker and refinery co-products or streams. Lower olefins provide the building blocks for the petrochemical industry with production of many other chemical intermediates and polymers reliant on these key raw materials.
Ethylene – also known as ethene - is the main product of steam cracking. The applications of ethylene are numerous and ethylene derivatives are traded around the world.
Polyethylene accounts for more than 50% of world ethylene demand. The primary use of polyethylene is in film applications for packaging, carrier bags and bin/trash liners. Other applications include injection moulding, pipe extrusion, wire and cable sheathing and insulation, as well as extrusion coating of paper and cardboard.
Ethylene is also the starting point for production of a number of key derivatives such as ethylene oxide, styrene monomer (via ethyl benzene) and higher olefins.
Propylene - also known as propene - is one of the major chemical building blocks and is produced as both a refinery grade (co-product of refinery catalytic cracking) and a chemical grade (co-product of the steam cracking).
More than 60% of the world's propylene is used to make polypropylene, one of the most widely-used and versatile products of the petrochemical industry.
Other materials derived from propylene include: acrylonitrile (which is converted to acrylic fibres and coatings); propylene oxide (which then goes into polyurethane resins and other chemicals); oxo alcohols (which are used in PVC plasticisers and coatings); cumene (which is ultimately used to make epoxy resins and polycarbonate); and isopropyl alcohol (which is used as a solvent).
As a result, propylene can be found in countless end use products including: automotive components; carpets; computer disks; clear film food wrap; eyeglasses; flexible and rigid foams; glazing; moulded plastic goods such as buckets, food containers, kitchen utensils and wastebaskets; nitrile rubber hoses, seals and gaskets; paints and protective coatings; grocery bags; synthetic fibres; and wood products such as plywood and laminates.
Butadiene, also known as 1,3-butadiene, is used in the production of styrene-butadiene rubber (SBR) principally for the manufacture of tyres. SBR is also used in adhesives, sealants, coatings and in rubber articles like shoe soles.
Butadiene is also a precursor for the production of acrylonitrile-butadiene-styrene (ABS), which is widely used in items such as telephones, computer casings and other appliances.
Other polymers made from butadiene include styrene-butadiene latex, used for example in carpet backings and adhesives; nitrile rubber, used in hoses, fuel lines, gasket seals, gloves and footwear; and styrene-butadiene block copolymers which are used in many end-uses ranging from asphalt modifiers to adhesives, footwear and toys.
Other chemical intermediates made from butadiene include adiponitrile and chloroprene which are used, respectively, in the manufacture of nylon and neoprene.
Isoprene is mainly polymerised to produce polyisoprene, a synthetic rubber which closely resembles natural rubber. Polyisoprene can be found in a wide variety of rubber applications including medical equipment, baby bottle teats/nipples, toys, shoe soles, tyres, and elastic films and threads for golf balls or textiles. It is also used in adhesives and in paints and coatings.
Butyl rubber, made from isobutene with a small amount of isoprene, has outstanding impermeability to gases and is used, for example, in inner tubes. Styrene-isoprene-rubber is another copolymer that is used in pressure sensitive adhesives. Isoprene can also be used in viscosity improver additives and in the production of agrochemicals, pharmaceuticals and other fine chemicals.
Dicyclopentadiene (DCPD) is used in many products ranging from high quality optical lenses through to flame retardants for plastics and hot melt adhesives. As a chemical intermediate it is used in insecticides, as a hardener and dryer in linseed and soybean oil, and in the production of EPDM (ethylene propylene diene monomer) elastomers, metallocenes, resins, varnishes, and paints.
DCPD-containing products are also used in the production of hydrocarbon resins and unsaturated polyester resins used to make boats, baths and water tanks.
Piperylene, also known as 1,3-pentadiene, is used as an intermediate monomer in the manufacture of plastics, adhesives and resins. Piperylene-based products are present in many modern adhesives, such as those used in the manufacture of envelopes, parcel tapes, diaper fastenings and road markings.
1-butene is primarily used as a co-monomer in polymerisation processes to make important chemicals such as linear low density polyethylene (LLDPE) more flexible and more resilient. The 1-butene is distilled to give a very high purity product and can be supplied alongside a broad range of polyethylene comonomers, including 1-hexene and 1-octene.
1-butene can also help to create a more versatile range of polypropylene resins and is used in the production of polybutene, butylene oxide and solvents such as secondary butyl alcohol (SBA) and methyl ethyl ketone (MEK).
Our key strengths in lower olefins
- Large scale integrated manufacturing locations in multiple regions
- Strong global supply and logistics capabilities
- Major player in the merchant market
- Long term involvement and commitment – more than 75 years - to the sector
- Leaders in product stewardship support, including best practices for handling butadiene
More in Chemicals product portfolio
Aromatics such as benzene, toluene and xylene, are key chemical building blocks used in the production of a range of chemical intermediates and polymers.