“Cellulose fibres can be produced in an efficient and environmentally sustainable manner by using ionic liquids.” This was the conclusion drawn following studies by BASF and the Denkendorf Institute for Textile Chemistry and Chemical Fibers (ITCF).

Practical tests carried out jointly by BASF and the ITCF for more than a year are said to have shown that the efficiency of the production process can be greatly enhanced by the use of ionic liquids. This is said to be because in ionic liquids, cellulose shows clearly better results for dissolving behaviour and technically useful concentrations. “Cellulose fibres produced by means of ionic liquids already have properties comparable to those of conventionally made fibres,” said Dr Eric Uerdingen from the New Business Development team at BASF’s Intermediates division.

Around the globe, most cellulose fibres are currently manufactured from so-called dissolving pulp by means of the viscose process. Although this technology has been improved continuously in the past decades, it consumes more than two metric tons of chemical additives and considerable fresh water volumes per metric ton of cellulose fibre made, requiring major wastewater treatment efforts. In contrast to this, the ionic liquids used as solvent can be almost entirely recycled. This also applies to the water required in fibre spinning. In addition to this, additive consumption drops significantly.

Since late last year BASF has also been collaborating with the University of Alabama (UoA) in the United States. This collaborative endeavour focuses on fundamental cellulose processing research with a view to expanding the use of renewable resources.

Occurring at a volume of some 700 billion tons, cellulose is the earth’s most widespread natural organic chemical and, thus, highly important as a bio-renewable resource. Even out of the 40 billion tons nature renews every year, only 0.1 billion tons are used as feedstock for further processing.

A more intensive exploitation of cellulose as a bio-renewable feedstock has to date been prevented by the lack of a suitable solvent that can be used in chemical processes. Now, the use of ionic liquids for the first time is said to permit a simple production of cellulose solutions at concentrations that are technically attractive. This new technology therefore opens up great potential for cellulose processing.

A more intensive exploitation of cellulose as a bio-renewable feedstock has to date been prevented by the lack of a suitable solvent that can be used in chemical processes. Now, the use of ionic liquids for the first time permits a simple production of cellulose solutions at concentrations that are technically attractive. This new technology therefore opens up great potential for cellulose processing.