Isopropanol (IPA) is a clear, colourless, mobile liquid with an alcoholic odour. It is miscible with water and ethyl alcohol and reacts with strong oxidants.
IPA, also known as isopropyl alcohol, is a low-cost solvent used in many industrial and consumer products and as an extractant. Outlets include cosmetics and personal care products, de-icers, paints and resins, pharmaceuticals, food, inks and adhesives. It is also used as solvent for oil and gums and in the manufacture of fishmeal concentrates. Low-grade IPA is used in motor oils.
Other applications include its use as a cleaning and drying agent in the manufacture of electronic parts and metals, and as an aerosol solvent in medical and veterinary products. It can also be used as a coolant in beer manufacture, a coupling agent, a polymerisation modifier, a de-icing agent and a preservative.
Some chemical compounds are manufactured from IPA, in particular derivative ketones, such as methyl isobutyl ketone (MIBK), isopropylamines and isopropyl esters.
Weather-related shipping delays in the Midwest and east coast during the winter, and closure of the Houston Ship Channel due to an oil spill, led to a tightening of supply.
Normally, that would lead to an increase in prices. However, buyers held back from purchasing to see how long the delays would last and what impact – if any – they would have on the IPA market. It was believed that buyers had already purchased enough product for the first quarter.
In early April, it was heard that US IPA suppliers were selling at a discount. This led to speculation that US suppliers have excess IPA they were trying to move. As IPA is used as a de-icer, demand appeared to inch up during the winter months. However, as the winter passed, demand from that sector levelled off.
IPA is also used in paints and resins, and could see increased demand as the summer construction season kicks off. In addition, low-grade IPA is used in motor oils, and an improved automotive sector could push IPA demand up.
The US IPA market during the first quarter of 2014 was a roller coaster of propylene-driven increases, shipping delays, a softening of prices and an eventual market correction.
ICIS-assessed prices of IPA increased 5 cents/lb in February. Producers had attempted an 8 cent increase. Some sources indicated that the full 8 cents did go through. However, it was determined that the 8 cent increase was not widespread, and was implemented on an account-by-account basis.
In late March, IPA prices fell 3 cents. Sources said the January and February increases were artificial, and that the market was correcting itself.
IPA market sources attending the International Petrochemical Conference (IPC) in San Antonio in late March speculated that IPA prices could remain flat for the second quarter of 2014, with a slight possibility of a 1 or 2 cent increase on the high end of current ranges.
There are two commercial routes used in manufacturing IPA. One is an older method based on indirect hydration of refinery-grade propylene (RGP). This process uses sulfuric acid to form isopropyl sulfate, which is then hydrolyzed with steam to form sulfuric acid and IPA. The crude IPA is then distilled to the desired purity.
The second route uses the direct hydration of chemical-grade propylene (CGP) (90-99%). This method eliminates the need for sulfuric acid. Instead, propylene and water are heated and the liquid-vapor mixture is pressurised, and passed into a trickle flow reactor containing sulfonated polystyrene (PS) ion-exchange resins. Alternatively, the reaction can be carried out in a gas phase over a phosphoric acid-based fixed-bed catalyst.
There is also a liquid-phase route employing a soluble tungsten catalyst. The IPA is distilled from the aqueous solution.
The IPA market is expected to remain steady throughout spring and into summer. However, as a propylene-derived petrochemical, any fluctuations in feedstock prices could have an impact.
IPA is also used in pharmaceutical and personal care products, and movement in those areas could increase demand and prices for IPA. However, sentiment in the market points to steady IPA prices over the next few months.