Comparison of different solvents

Examples of more recent work on this topic have been published, for example by Hellweg et and Bauer and Maciel using LCA for the comparison of different solvent alternatives... 

A systematic review and comparison of different solvents and aqueous-to-solvent ratios for isoflavone extraction efficiency. 

TABLE IV. Comparison of Different Solvents In the Depolymerization of Consolidation Coal... 

Originally, the empirical solvent parameters have been introduced to provide guidelines for the comparison of different solvent qualities and for an orientation in the search for an understanding of the complex phenomena in solution chemistry. Indeed, the choice of the right solvent for a particular application is an everyday decision for the chemist which solvent should be the best to dissolve certain products, and what solvent should lead to increased reaction yields and/or rates of a reaction ... 

Table 6 Comparison of Different Solvent Emission Control System...

Air-Organic Solvent and Other Partition Constants Comparison of Different Organic Solvents... 

Comparison of Different Organic Solvent-Water Systems... 

DDT, dieldrin Hexane-isopropanol, hexane-acetone, hexane-isopropanol, acetone Comparison of different extraction solvents [293]... 

The effect of different solvents has been studied in photoinitiated SRN1 reactions. However, the marked dependence of solvent effects on the nature of the aromatic substrate, the nucleophile, its counterion and the temperature at which the reaction is carried out often make comparisons cumbersome. 

Comparison of different compounds in the same solvent distinctly indicates a decrease in AO from left to right (Table I). This may correspond to an increase in acidity, i.e., to an increasing proportion of the colored form (8) in this direction.29... 

A greater contrast is provided by the first-order rate of decarboxylation of malonic acid. In Table XV.4 are gathered some data from a compilation of Clark (Zoc. dt) on the effect of different solvents. The data in H2O of Hall (Zoc. cit.) are included for comparison purposes. Here, over a range... 

These several assumptions do not lead to the same conclusions. For example, transfer activity coefficients obtained by the tetraphenylarsonium tetraphenyl borate assumption differ in water and polar aprotic solvents by up to 3 log units from those based on the ferrocene assumption. From data compiled by Kratochvil and Yeager on limiting ionic conductivities in many organic solvents, it is clear that no reference salt can serve for a valid comparison of all solvents. For example, the tetraphenylarsonium and tetraphenyl borate ions have limiting conductivities of 55.8 and 58.3 in acetonitrile. Krishnan and Friedman concluded that the solvation enthalpy of... 

In Germany, production plants for extracts, e.g. hop extract, are operated with subcritical separation (Figure 6). In these plants, heat recovery measures may significantly reduce the energy consumption. Energy calculations were performed for the example of a SCF extraction plant for processing 15 t hops/24 h with extraction at 300 bar and 60 C, separation at 60 bar and 40 C, a specific solvent mass flow of 10 kg CO2 / (h kg. hops) and an extraction time of 4 h. A comparison of different process variants for... 

Kxcii is the acidity constant of the acid and K-Raae is the basicity constant of the base. For a corresponding acid-base system, AAcid is the reciprocal of ABase- In equations (4) and (5) [aH ] denotes the proton activity, and ca and cb are respectively the conventional activities of the acid and the base and are set equal to the concentration c in very dilute solutions. The hydrogen ion activity on the contrary is expressed in absolute units and at first glance it seems rather arbitrary to make the distinction. We shall see, however, that (4) and (5) give us practical and serviceable expressions for the acidity and basicity constants which now permit comparisons between different solvents. 

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