Experimental and modeling studies on the solubility of sub‐ and supercritical carbon dioxide (scCO₂) in potato starch and derivatives

Abstract

The solubility of CO2 in native potato starch (NPS) and potato starch acetate (SA) at two different temperatures (50°C and 120°C) and various pressures (up to 25 MPa) was determined using a magnetic suspension balance. Within the experimental window, a maximum solubility of 31 mg CO2/gsample for NPS and 79.4 mg CO2/gsample for SA was obtained. The CO2 sorption behavior is highly depending on the temperature and pressure. The solubility data were modeled with the Sanchez Lacombe equation of state (S‐L EOS). The swelling (Sw) values, as predicted using the S‐L EOS, were relatively small and a maximum value of 6.1% was obtained for SA at 25 MPa and 120°C. POLYM. ENG. SCI., 2011. © 2010 Society of Plastics Engineers

Process‐product studies on starch acetylation reactions in pressurised carbon dioxide

“…Similar observations are known for a range of reactions carried out in supercritical CO 2 . For the system under study, the optimum pressure of 15 MPa is likely the results of two opposing effects, improved solubility of CO 2 and associated higher mass transfer rates of AAH in the starch matrix when increasing the pressure to the critical point and a compressive effect at higher pressures leading to a reduction in the free starch volume and lower mass transfer rates [Muljana et al , submitted; 13, 14, 24–27].…”

“…We have recently reported exploratory studies on the synthesis of starch acetate in pressurised CO 2 using acetic anhydride as the reagents and sodium acetate as catalyst in sub‐ and supercritical CO 2 12. In addition, thermodynamic properties of the system starch/CO 2 like CO 2 solubility 13 and effects of CO 2 on starch gelatinisation 14 have been explored.…”

Thermoplastic starch and glutaraldehyde modified thermoplastic starch foams prepared using supercritical carbon dioxide fluid as a blowing agent

“…For example, cell densities (cell diameters) of the scCO 2 a TPS series varied from approximately 1.1 × 10 8 cells/cm 3 (approximately 230 μm) to approximately 1.6 × 10 8 cells/cm 3 (approximately 210 μm) and to approximately 2.8 × 10 8 cells/cm 3 (approximately 160 μm), as scCO 2 pressure increased from 7 to 9 and to 11 MPa, respectively. The increase in cell density of scCO 2 a TPS foams with increasing scCO 2 pressure is most likely attributed to the presence of increased soluble amounts of scCO 2 during the foaming processes . As reported by Tsivintzelis et al, the key factor that controls the cell size is the generation of more nuclei as pressure increase, which in turn leads to structures with increased cell density.…”

Supercritical carbon dioxide and polymers: an interplay of science and technology

“…These are usually measured by using a magnetic suspension balance . However, theoretical approaches also remain popular in view of the possibility of garnering an a priori estimation of both quantities. This is not trivial since even small changes in the chemical structure of the polymer can have a dramatic influence on the solubility .…”