Propylene, also called propene, a colourless, flammable, gaseous hydrocarbon, C3H6, obtained from petroleum; large quantities of propylene are used in the manufacture of resins, fibres, and elastomers, and numerous other chemical products. As for its physical properties, it is a gas at room temperature, is soluble in hydrocarbon solvents, it is flammable, combustible, and has a low flash point, and also has a faint butane-like odor. The melting point of propylene is −169.4 °C [−301.4 °F], and its boiling point is −47 °C [−53.8 °F]. Propylene is second only to ethylene as an important raw material for producing other organic chemicals and, like ethylene, it has virtually no use “as-is”. Rather, it used alone (as in production of Polypropylene) or after reaction with other chemicals (as in production of acrylonitrile, propylene oxide and oxo-alcohols) for a large variety of industrial products.
Propylene was invented in 1950 by Fontana and is characterized by disorderly structure with an elevated molecular weight. The first commercial FCC unit was built by The M.W. Kellogg Company in Standard Oil of New Jersey’s Baton Rouge, Louisiana refinery and commissioned in May 1942. Between 1942 and 1944 Kellogg built 22 of 34 FCC units constructed throughout the U.S, and the FCC process quickly became a major contributor to worldwide propylene and butylene production.
There are several major licensors of conventional commercial olefin technologies, including: Lummus Technology, KBR, Linde, Technip, and the Shaw Group. In addition to the traditional pyrolysis and recovery technologies, new routes to ethylene and propylene production are being developed. The nameplate capacity for today’s worldscale crackers can well be over 1,000,000 MTY of propylene. Naphtha is the predominate feed for steam crackers.
BASF SE, China National Petroleum Corp. (CNPC), Eni SpA, Enterprise Products Partners L.P., Exxon Mobil Corp., Formosa Plastics Group (FPG), Ineos Group Ltd., LyondellBasell Industries AF S.C.A., Reliance Industries Ltd., Royal Dutch Shell PLC, Saudi Basic Industries Corp. (SABIC), Sinopec Corp., The Dow Chemical Company, Total S.A., Valero Energy Corp. are some of the leading producers of Propylene.
Global propylene capacity was 97.7MMT in 2011 against a demand of 80 MMT. The capacity is expected to increase to 119 MMT in 2015 with demand reaching 98MMT. SABIC, Borouge, Dow, IRPC Pcl (Thailand) and Reliance Industries Ltd are some of the companies which announced ethylene capacity expansion plans starting 2012 to 2017. In India total ethylene capacity is expected to reach 4987 KTA by 2016-17 and Reliance Industries Ltd has planned capacity expansion to2898 KTA by 2016-17 followed by IOC at 565 KTA, HMEL at 450, HPL Halida at 345 KTA, ONGC OPAL at 340 KTA, and BPCL at 170 KTA.
Polypropylene and other propylene based derivatives, such as propylene oxide and acrylonitrile, have strong positions in durable goods production. The automobile and housing industries, as they begin to recover, will remain dependent on these materials. Increased utilization of plastics in automobiles to lighten weight and thus improve mileage will offer further growth opportunities. A rapidly evolving consumer base in Asia (mainly China and India) continues to drive demand growth for propylene based derivatives. Growth of propylene derivative demand in India is also being fueled by consumers moving into the middle class.
Meanwhile, Propylene prices have increasingly become volatile from 500 $/tonne (Spot CFR NE Asia) in April 2002 it has touched close to 1500 $/tonne in recently in March 2012 and currently at 1150 $/tonne in June 2012. (Source ICIS)
Polypropylene can be processed by virtually all thermoplastic-processing methods. Most typically PP Products are manufactured by: Extrusion Blow Moulding, Injection Moulding, and General Purpose Extrusion. PP applications include Buckets, bowls, crates, toys, medical components, washing machine drums, battery cases, bottle caps. Elastomer modified for bumpers, etc. Talc filled for additional stiffness at elevated temperatures - jug kettles, etc. OPP films for packaging (e.g. crisps, biscuits, etc.). Fibres for carpets, sports clothing and Geotextiles for erosion
Propylene production in refineries:
In a crude oil refinery, propylene is a coproduct of FCC units producing useful lighter products from atmospheric and vacuum gas oils. An FCC unit transforms these heavy oils into motor gasoline, fuel oils and significant quantities of olefins, especially butylenes and propylene.The main purpose of refinery is to produce motor gasoline and various grades of fule oils by separating crude oil into useful high value fractions and converting the other fractions into high value components by various specialized processes.
Propylene production in refineries
Catalytic dehydrogenation of propane produces propylene. This process is attractive when the local propane supply is abundant and steady, with a stable price structure relative to propylene. Two predominant propane dehydrogenation technologies are available, the UOP Oleflex process and the Lummus Catofin process.
Metathesis – the catalytic disproportionation of ethylene and butene – is an alternative method for the on purpose generation of propylene. This process enables propylene production from other olefinic products generated in an FCC unit or olefin plant.
Another potential propylene production technology, Methanol-to-propylene (MTP), is a catalytic conversion process developed by Lurgi. It is much like MTO process (as in ethylene section), but the products are propylene, gasoline, fuel gas and LPG rather than short chain olefins.