Supercritical carbon dioxide comparison

Michor, H. Marr, R. Gamse, T. Schilling, T. Klingsbichel, E. Schwab, H. Enzymatic Catalysis in Supercritical Carbon Dioxide Comparison of Different Lipases and a Novel Esterase. Biotechnol. Lett. 1996b, 18, 79-84. Miller, D. A. Blanch, H. W. Prausnitz, J. M. Enzyme-Catalyzed Interesterification of Triglycerides in Supercritical Carbon Dioxide. Ind. Eng. Chem. Res. 1991, 30, 939-946. 

H Michor, R Marr, T Gamse, I Schilling, E Klingsbichel, H Schwab. Enzymatic catalysis in supercritical carbon dioxide comparison of different lipases and a novel esterase. Biotechnol Lett 18(l) 79-84, 1996. 

Gomez AM, Lopez CP and de la Ossa EM. 1996. Recovery of grape seed oil by liquid and supercritical carbon dioxide extraction a comparison with conventional solvent extraction. Chem Eng J 61(3) 227—231. 

M. Khasjeh, Y. Yamini, F. Sefidkon and N. Bahramifar, Comparison of essential oil composition of Carum copticum obtained by supercritical carbon dioxide extraction and hydrodistillation methods. Food Chem. 86 (2004) 587-591. 

Agricultural processing will still incorporate solvents. As an example, soybean flakes were extracted with supercritical carbon dioxide to produce a solvent-free, good-quality soybean oil. During the SFE process, volatile compounds were trapped on a porous polymer trap attached at the exhaust port of the SFE apparatus. The volatile profile obtained from the sorbent trap was found to be similar to the headspace profile from the SFE/soybean oil removed during the same extraction. In addition, crude soybean oil was heated in a stirred reactor and the volatiles, which were stripped by supercritical carbon dioxide in an attempt to improve oil properties, were collected on sorbent traps and analyzed by the above method for comparison. The described methodology permits the characterization of volatiles and semivolatUes in SEE soybean oil and can be used to monitor the extraction and quality of the resultant oil (Snyder and King, 1994). 

Figure 6 Comparison of the rate constants in supercritical carbon dioxide to those in liquid isopropanol at high pressures (Okamoto, 1990).

G. Durand, Comparison of lipase-catalyzed esterification in supercritical carbon dioxide and in u-hexane, Biotechnol. Lett. 1990, 12, 11-16. 

Dumont, T. Barth, D. Corbier, C. Branlant, G. Perrut, M. Enzymatic Reaction Kinetic Comparison in an Organic Solvent and in Supercritical Carbon Dioxide. Biotechnol. Bioeng. 1992, 39, 329-333. 

Guan, W., Li, S., Yan, R., Tang, S. and Quan, C. (2007) Comparison of essential oils of clove buds extracted with supercritical carbon dioxide and other three traditional extraction methods. Food Chemistry 101 (4), 1558-1564. 

The present work reports results and observations on the enzymatic synthesis of oleyl oleate (which is a synthetic analogue of jojoba oil) in supercritical carbon dioxide. Special stress was laid on the comparison between batch and continuous systems for the above mentioned synthesis. Influence of different reaction parameters on the reaction yield and initial reaction rates was studied. 

Recently supercritical carbon dioxide has been used as a solvent in dyeing textiles and fibers. In comparison with conventional techniques, this method has the advantage of complete separation of the remaining dyestuff from the solvent. Furthermore, there is no need in purification of waste water or in drying textiles [1-5]. 

As a comparison and reproduction to recent works done by DeSimone and coworkers [2], attempts were made in the free radical polymerization of acrylic acid (AA) in supercritical carbon dioxide (SCCO2) with Azoisobutyronitrile (AIBN) as initiator. 

Fratianni, A. Carboni, M.F. Irano, M. Panfili, G. 2002. A critical comparison between traditional methods and supercritical carbon dioxide extraction for determination of tocochromanols in cereals. Eur. Food Res. Tech. 215 353-358. 

Supercritical or high pressure carbon dioxide can induce polymer crystallization and plasticize polymers. The systematic study on the interaction of carbon dioxide with twenty different crystalline and amorphous polymers has been performed and various influencing parameters have been determined. Through the examination, analysis and comparison of the yield strength, ultimate elongation and modulus both before and after treatments in supercritical carbon dioxide at 3000 psi and 70°C, it was found that two main factors, i.e., degree of crystallinity and the presence of a polar side chain group, e g., ester. 

Comparison of a supercritical carbon dioxide cleaning system with two non-carbon dioxide systems using the SEMATECH cost-of-ownership model. 

Comparison of the Use of Different Types of Membranes for Caffeine/Supercritical Carbon Dioxide Membrane Separation... 

Reis-Vasco EMC, Coelho JAP, Palavra AMF. Comparison of pennyroyal oils obtained by supercritical carbon dioxide extraction and hydrodistillation. Flavour Fragrance J 1999 14 156-160. 

Figure 6.6 Comparison of SFC with HPLC packed columns. When mixed with methanol and additives, supercritical carbon dioxide allows the rebuilding of the whole range of polarities required by the principal types of analyte.

Figure 8.7 Comparison of effects of mass transfer limitations in the desorption of alachlor from activated carbon using supercritical carbon dioxide tests with several flow rates and carbon mesh size. SLPM = Standard liters per minute.

By factoring out solute volatility, the enhancement factor allows comparison of solvent and secondary solute effects. Empirically, there is a linear relationship between the log of the enhancement factor and solvent density. For nonpolar and polar solutes in supercritical carbon dioxide, plots of enhancement factor coincide, indicating that differences in solubility are primarily due to vapor-pressure differences. Nonlinear behavior is noted in the case of high solubilities. The enhancement m pure fluids is relatively independent of solute structure but is sensitive to solvent polarity and density. 

Variations in the thomal properties (v and vi from above) and the mechanical properties (vii from above) for polymaic materials are discussed sq arately in Sec. 3. This section details our results on sorption and swelling of polymers by carbon dioxide and the dissolution characteristics of various polymeric materials under a variety of conditions. A comparison will be shown for wdght change data of twenty different polymers that have been treated in both sub- and supercritical carbon dioxide at seven different conditions. These results are discussed in general to isolate important factors which affect the weight change (and possibly dimensions) of polymers. 

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