Cumene is used almost exclusively (about 98% of output) to make phenol and co-product acetone. Other uses are as a thinner for paints, lacquers and enamels, as a constituent of some petroleum-based solvents, and in high octane aviation fuel.
It is also used in the manufacture of polymerisation catalysts, catalysts for acrylic and polyester type resins, and as a raw material for peroxides and oxidation catalysts.
Another use is in the manufacture of cumene sulphonic acid, used as a catalyst in some esterification syntheses, but more importantly for sodium (or ammonium) cumene sulphonate used in detergent and household liquids. This outlet consumes about 5000 tonne/year cumene in western Europe.
Europe remains net short of cumene and sources most of its shortfall from the US. There has been better availability of cumene this year compared to last because of more slack in the US system. Demand has fallen off in the US and new cumene and phenol capacity in Asia has backed out US exports. Additional capacity went onstream in the first half of 2005 for Kumho P&B Chemicals and LG Petrochemical in South Korea, Chang Chun Petrochemical in Taiwan and Shanghai Gaoqiao Petrochemical in China.
European consumption into phenol has been healthy this year and cumene units are running well and at near capacity. Players say supply and demand is quite balanced.
Domo CaproLeuna is up for sale and the company said a sale could be achieved by January 2006.
The European merchant market is very limited with most major cumene producers integrated downstream into phenol production. Most European and US prices are fixed according to formulae based on benzene and propylene feedstock costs.
In the US, the August contract cumene price was calculated at 37.5 cent/lb fob (based on industry formulae), down from July’s level of 38.5-39.0 cent/lb. Cumene prices reached a record high of 53 cent/lb in November 2004 driven by rocketing benzene prices.
Modern cumene technology is based on the reaction of propylene and benzene either in the liquid or gas phases. These processes initially used solid phosphoric acid (vapour phase) or aluminium chloride (liquid phase) catalysts.
However, in recent years, production economics have been radically changed by processes which use zeolite catalysts with a rapid shift, particularly in the US, to these zeolitebased systems. These routes offer lower costs through high benzene-to-cumene selectivity, high product purities and the ability to regenerate the catalyst, eliminating the problem of waste disposal.
A further development has been the combination of the catalytic reaction with distillation in a single column, using the heat from the exothermic reaction in the distillation and thus reducing the amount of energy required.
HEALTH AND SAFETY
Cumene is a colourless, flammable liquid with a characteristic odour. It reacts violently with acids and strong oxidants. It is a fire and explosion hazard and above 31°C explosive vapour/air mixtures may be formed and there is a risk of flashback. Vapour can irritate the eyes and nose and excessive exposure can lead to headaches and narcosis.
The outlook for cumene is tied very closely to phenol and its derivatives, particularly bisphenol A and polycarbonate (PC). The global phenol market is tipped to grow at over 4%/year to 2009. The PC sector is tipped to grow at an average 8%/year down from the highs of 11%/year seen in recent years.
For cumene, DeWitt’s latest forecast puts average growth in the period 2005-10 at 1.9%/year in western Europe, and 3.8%/year globally. DeWitt says that about 2m tonne/year additional capacity worldwide will be needed to total 15m tonne/year by 2010, specifically 600 000 tonne/year in North America, 400 000 tonne/year each in eastern Europe and Asia-Pacific, 285 000 tonne/year in western Europe, 250 000 tonne/year in the Middle East and 70 000 tonne/year in Latin America.
The main challenge for cumene in the future is the shortage, and potentially higher price values, of benzene and propylene feedstocks. Cumene (and phenol/acetone) will have to compete with other derivatives such as styrene and polypropylene for benzene and propylene molecules.
EUROPEAN CUMENE CAPACITY, ’000 TONNE/YEAR
|BP||Gelsenkirchen, ?Germany?Marl, Germany||498??250|
|Dow Chemical||Terneuzen, ?Netherlands||700|
|Lukoil Neftochem||Burgas, Bulgaria||45|
|Omsk Kauchuk||Omsk, Russia||100|
|Polimeri Europa||Torro Torres, Italy?Priolo, Italy||300?320|
|SSME Azot||Severodonetsk, Ukraine||30|
Profile last published 4 August 2003; Chemical Profile is published fortnightly.