Ethanol is already used in many of Perstorp’s polyols. Historically, ethanol has also been a raw material in the production of butyraldehyde, which is the core of chemical production. Because of the price increase in mid-2008 ethanol has once again become topical as a suitable raw material in the chemical industry.
Perstorp is examining ways of once again producing butyraldehydes from ethanol with the help of modern technology.
Projects are being run where ethanol to ethylene could be building blocks for both plastics and chemicals, which would then be completely renewable.
Along with ethanol is butanol, which is an alcohol not too dissimilar to ethanol. This can also be generated by fermenting the same raw materials. Perstorp currently produces butanol and are looking at ways of how fermentation can be used to produce butanol from renewable raw materials, which would then be bio-butanol.
The most common way of producing renewable ethanol is by fermenting sugar and starch-rich raw materials. The US produces the most ethanol, closely followed by Brazil. Europe is lagging far behind in third place. Almost all ethanol produced in the US is from maize, which is crushed and pre-treated to become a porridge-like mash, which is then fermented. Fermentation takes place by yeast breaking down glucose under anaerobic conditions, forming ethanol in the glucose due to lack of oxygen.
The ethanol process using sugar cane as a raw material has a similar fermentation process. The difference is that when the sugar can is crushed you get a sugary juice, which the yeast then converts to ethanol. This avoids the conversion of starches to glucose (sugar).
Wheat is used as a raw material in Europe and the process is similar to that of maize. The biggest difference between maize, wheat and sugar can is the price. Wheat is the most expensive, making it difficult for European ethanol producers to compete with sugar can-based ethanol.