Carbon dioxide, addition

Hotchkiss, J. H., Chen, J. H., and Lawless, H. T. (1999). Combined effects of carbon dioxide addition and barrier films on microbial and sensory changes in pasteurized milk. J. Dairy Sci. 82, 690-695. 

Ruas Madiedo, P., Bada Gancedo, J. C., Fernandez Garcia, E., Gonzalez de Llano, D., and Reyes Gavilan, C. G. D. L. (1996). Preservation of the micobiological and biochemical quality of raw milk by carbon dioxide addition a pilot-scale study. /. Food Prot. 59, 502-508. 

Stanton and Merz studied the reaction of carbon dioxide addition to zinc hydroxide, as a model for zinc metallo-enzyme human carbonic anhydrase IIJ 36. It was shown that the LDA calculations (DFT(SVWN)) were not reliable for locating transition state structures whereas the post-LDA ones (DFT(B88/P86)) led to the transition state structures and ener-... 

The original permeability could be regained when the steam addition was stopped. However, this was not the case when adding carbon dioxide to the feed instead of steam. This decreased the hydrogen flux from 90 to 13 Ndm3 m-2 s 1 and the permeability was lower than before, when carbon dioxide addition was stopped. This effect was attributed to carbon formation on the membrane surface. 

STD of refined methanol to the US Federal Grade AA specification. The unit is based on natural gas feedstock and was the first plant operating under low carbon concept conditions, i.e., carbon dioxide addition to improve the stoichiometry of the synthesis gas is not required. This unit is based on centrifugal compression throughout and includes three distillation columns. 

Reduction of sodium sulphate with charcoal at red heat produces sodium sulphide and carbon monoxide, along with sodium polysulphides and carbon dioxide. Addition of alcohol to a solution of sodium sulphate in aqueous hydrogen peroxide precipitates a complex derivative of the formula Na2SO H O,H202.10... 

As has already been described in Table 9.1, transport properties are enhanced in CXLs compared with conventional solvents. For example, diffusivities of solutes are enhanced up to 7-fold in carbon dioxide expanded methanol, with little effect being seen on the nature of the solute (benzene pyrazine). Therefore, it is thought that physical rather than chemical interactions are causing this phenomenon, including reduced viscosity and surface tension upon carbon dioxide addition. The solubility of solids, liquids and gases in CXLs will... 

Matsui, J. Sodesawa, T. Nozaki, F. Influence of carbon dioxide addition upon decay of activity of a potassium-promoted iron oxide catalyst for dehydrogenation of ethylbenzene. Appl. Catal. 1991, 67, 179-188. 

The composition of the produced biogas is typically about two-thirds methane and one-third carbon dioxide. Additionally the biogas may contain trace substances such as H2S, depending on the composition of the biomass, the process conditions and other parameters. The LHV of biogas, which depends mainly on methane content, ranges from 14 to 29 MJ m. ... 

Colourless liq. F.p — 63-5 . B.p. 61-2 . Sol. to 1% in HjO at 15 . Sol. EtOH. Et.,0. CgHg, McjCO, CSg. D 1-49843. Non-inflammable. Forms a hydrate with 18H. Forms constant-boiling mixture with 7% EtOH, b.p. 59 , and ivith 2-5% H,0. b p. 56 . < 1-44858. Mol. b-p. elevation, 38-8. Sp. heat at -20 , 0-234. Dissolves resins, fats, waxes, rubber, iodine, ozone, etc Decomposes slowly in air and especially in sunlight, giving phosgene, chlorine, hydrogen chloride, water, and carbon dioxide.. Addition of a small amount of EtOH retards the... 

Of critical importance, analysis of poly(methyl methacrylate) (PMMA) showed that at a saturation temperature, T, of 40°C, a saturation pressure, P%, of 1,500 psig (at these conditions, carbon dioxide is considered a supercritical fluid), and a saturation time, ts, of 24 h, a 1 mm thick disk absorbed 16.4 wt% carbon dioxide. Additionally, at a foaming temperature, Tf, of 120°C and a foaming time, tf, of 1 min, PMMA had a stable volumetric expansion ratio of 20. Other polymers also absorbed significant quantities of carbon dioxide, such as polystyrene (PS) and poly(vinylidene chloride-co-acrylonitrile) (P(VDC-AN)), which absorbed 8.9 and 2 wt% carbon dioxide, respectively, yet the stable foams that were formed had expansion ratios of less than 2 at the same conditions used to form the PMMA samples. Another polymer poly(vinyl methyl ketone) (PVMK) achieved an expansion ratio of 20. However, the foams were unstable, readily collapsed, and exhibited large voids ( 5 mm diameter), which are inconsistent with microcellular foams. The fact that PVMK readily collapsed after the foaming process made it difficult to determine the concentration of carbon dioxide in the sample. These results led to the eventual incorporation of the MMA monomer into the polymer formulation from the standpoint of carbon dioxide-induced microcellular foamability. 

Herskowitz T, Guggenberger L (1976) Carbon dioxide coordination chemistry. The stmcture and some chemistry of the novel carbon dioxide addition product chlorobis(carbon dioxide) tris(trimethylphosphine)iridium. J Am Chem Soc 98 1615-1616... 

Temperature influences fermentation kinetics. The alcohol yield is generally lower at elevated temperatures, in which case some of the alcohol may be entrained with the intense release of carbon dioxide. Additionally, most of the secondary products of glyceropyruvic fermentation are found in greater concentrations. Fatty acids, higher alcohols and their esters are the most affected their formation is at its maximum at about 20°C and then progressively diminishes. Low fermentation... 

How is this insured Many instruments can be purged with gases such as dry nitrogen. The flow of purge gas through the instrument reduces the concentration of water vapor and carbon dioxide. Additionally, the subsequent reduction in humidity helps to preserve sensitive optical parts such as the KBr windows used in beamsplitters. Many instruments currently manufactured have sealed and desiccated interferometers. In these instruments the interferometer has a cover over it and a seal isolating it from the atmosphere. A desiccant pack is contained under the cover that removes water vapor and CO2 from the atmosphere around the interferometer. This again helps reduce the concentration of water vapor and CO2 and helps to protect the beamsplitter. 

---