New 'green' solvent could help clean our air: study

Researchers have developed an eco- friendly liquid mixture that could help trap harmful pollutants from the air.

The non-flammable solvent contains urea and choline salt, a common ingredient in chicken feed, said researchers from Unite de Chimie Environnementale et Interactions sur le Vivant in France.

Harmful gaseous pollutants in the form of volatile organic compounds are often released into the air when chemicals are used, for example in cleaning products.

Many methods have already been developed to clean contaminated air, for instance, liquid mixtures that can absorb and trap volatile organic compounds are often used.

Although effective, many of the current methods can be quite expensive, toxic or even unstable, researchers said.
 

They focused their attention on deep eutectic solvents, which are made by mixing two compatible components together to form a resulting liquid product at room temperature.

Laboratory studies were conducted to test how well each new mixture in their liquid forms could absorb three harmful volatile chemicals. These were toluene, acetaldehyde and dichloromethane.

The researchers measured their partition coefficients between the vapour and liquid phases for seven different deep eutectic solvents.

A solvent based on choline chloride and urea was found to dissolve up to 500 times more harmful chemicals than is possible with water at 30 degrees Celsius.

According to Leila Moura, lead author of a study published in the journal Environmental Chemistry Letters, there are many reasons why deep eutectic solvents should be considered when it comes to cleaning air.

Their absorption ability is similar or even superior to ionic liquids and organic solvents of similar purpose.

Moura said that, in general, deep eutectic solvents are easier to prepare and more biodegradable than potentially toxic ionic liquids.

Such solvents are also more biodegradable than the commonly used but more expensive silicone oils, she said.