Starch modifications in supercritial CO2

Promotie: dhr. H. Muljana, 13.15 uur, Academiegebouw, Broerstraat 5, Groningen

Proefschrift: Starch modifications in supercritial CO2

Promotor(s): prof.dr.ir. L.P.B.M. Janssen, prof.dr.ir. H.J. Heeres, prof.dr. F. Picchioni

Faculteit: Wiskunde en Natuurwetenschappen

Contact: Henky Muljana, tel. 62222032700, e-mail: hmuljana@yahoo.com

Starch modifications in supercritial CO2

Supercritical CO₂ is potential to be applied as the solvent alternative in the starch modification as it plays a special role both in physical and chemical modification of the starch, concludes Henky Muljana in his thesis. The development and application of environmentally benign solvents for the chemical industry is of prime importance to reduce emissions of traditionally used organic solvents. Among the various green solvents available, supercritical CO₂ (scCO₂) is considered a very promising option. It is not toxic, relatively inert and is known to have a positive effect on the rate and selectivity of many chemical reactions.

Chemical modification of starch is commonly carried out in aqueous media. Though water is considered a green, environmentally benign solvent, the use of water in starch modification reactions has several drawbacks such as reduced selectivity due to side reactions involving water, and high energy expenses to remove the water in the product work-up.

The goal of the PhD project of Muljana was to assess the application of scCO₂ as an alternative solvent for water and organic solvents such as dimethyl sulfoxide (DMSO) and pyridine for chemical starch modification. His research covers in-depth experimental and modeling studies, with a focus on the esterification of starch with acetic anhydride (AAH) and fatty acid derivatives, and also provides insights on a fundamental level on starch-CO₂ interactions. Moreover, Muljana determined important product properties such as viscosity, hydrophobicity, and thermal properties of the products and compared them with the products made in water.