Liquid impurities

The washing of filter cake is carried out to remove liquid impurities from valuable solid product or to increase recovery of valuable filtrates from the cake. Wakeman (1990) has shown that the axial dispersion flow model, as developed in Sec. 4.3.6, provides a fundamental description of cake washing. It takes into account such situations as non-uniformities in the liquid flow pattern, non-uniform porosity distributions, the initial spread of washing liquid onto the topmost surface of the filter cake and the desorption of solute from the solid surfaces. 

The washing of filter cake is carried out to remove liquid impurities from the valuable solid filter cake or to increase the recovery of valuable filtrate. Wake-man (1990) has shown that the axial dispersion flow model, as developed in... 

These supported cycloadducts were then treated with a base (LiOH, NaOH) in a mixture of water and alcohol to give the expected free acid derivatives. However, while the latter compounds were readily recovered, the same was not true for the ionic liquid 4b, which was obtained as a dark brown liquid impure by NMR analysis. Very likely, the basic hydrolysis of the ester function caused the deprotonation of the imidazolium ring leading to a series of undesired side-reactions. Therefore, milder reaction conditions were explored to cleave the Diels-Alder product from the ionic liquid support. Handy and Okello found that the best method was the cyanide-mediated transesterification that gave the corresponding methyl esters 9-11 and allowed recover of 4b in at least 90% yield. It was also demonstrated that the recovered 4b could be used for further supported syntheses. In fact, in two subsequent mns the yields of the final ester compound were similar, indicating that the ionic liquid 4b could be efficiently recycled. 

These two methods can be adapted for use in the commercially attractive area of polymer bound sensors. These offer, especially when coupled with fibre optics, a safe way of examining flammable solvents for their composition and levels of liquid impurities. 

Synonym Liquid Hydrogen Liquid Impure Camphor Liquid Nitrogen Liquid Nitrogen Dioxide Liquid Oxygen Liquid Petrolatum Liquified Phenol Litharge... 

Since liquid impurities may produce exudates in explosive compositions, to avoid this the crude product should be purified. For a preliminary washing, a dilute (2%) solution of sodium carbonate may be used. Picric acid reacts with the carbonate which then goes into solutions as sodium picrate. Instead of sodium carbonate milk of lime or calcium hydrogen carbonate may be used. 

Plant extracts from which expressed proteins are separated are very different from animal biological liquids. Impurities include not only foreign proteins but also peculiar lipids and polysaccharides, depending on the plant organ. The presence of polyphenols must also be considered for separation by chromatography. One of questionable characteristics of antibodies expressed... 

In course of crystallization the liquid impurities including solved gas are trapped in the solid layer. During expansion the volume of the enclosed gas is increasing and breaks up the solid, so that impurities are transported to the surface without remelting parts of the crystals. 

The final purity after the pressure sweating step is limited by the melt which adheres at the porous crystal layer. Therefore there is no significant difference between the experiments under 15 bar C02, 50 bar N2 and 175 bar N2 atmosphere which means that there is already enough gas solved at 15 bar CO2 respectively 50 bar N2 in the liquid impurities to transport them with the escaping gas to the crystal layer surface. 

The apparatus for open-tube diffusion consists of a silica furnace tube with a continuously flowing gas. The exit end may be at atmospheric pressure or at reduced pressure. The impurity source may be a vaporizing solid whose vapors are carried to the semiconductor by a carrier gas. The carrier gas may be bubbled through a liquid impurity source. The carrier gas takes up source molecules, which then decompose at elevated temperatures. Liquid sources are maintained at or near room temperature. This arrangement has an advantage over the use of solid sources in terms of easier control of source temperature and, thus, impurity concentrations in the carrier gas. 

Fig. 3 Effect of the content of the impurities water (filled circles) and 1-methylimidazole (open circles) on the resulting peak areas (and hence vapour pressure) of 1 pL toluene in [C6mim]Cl (ionic liquid + impurity = 7.872 mmol) [74]...

Slag (in metallurgical processing) refers to the solid or liquid impurities removed from molten metal. 

Multistage AFS systems are highly efficient in the removal of solid and liquid impurities in air however, vapors pose risks of accelerated GT corrosion. The development of filtration solutions for vapor removal remains an active area of research [41],... 

After condensation, the liquid impurities are not warmed very much before they are removed to prevent re-evaporation. To accomplish this, the heat exchanger is separated into three vertically mounted sections, as shown in Fig. 5, with impurity removal taps at the bottom of each section. ITie liquid impurities which are removed from the first tap, if at room temperature, are pentane, butane, and water. The second tap drains off principally propane and ethane while the last removes methane. The heat exchangers used are of the Giauque-Hampson type shown in Fig. 2. The impure gas flows on the outside of the tubes while the purified gas flows countercurrent through the inside of the tubes. 

The liquid impurities are drained off every fifteen minutes and exhausted in a nearby field where they eventually evaporate. No attempt is made to recover either the gas or the refrigeration in the cold liquids. With comparatively few modifications in the system, a considerable saving in purifier refrigeration requirements could be made by heat exchange with the exhausting gases. However, since the purifier refrigeration requirements are small relative to the liquefiers, the additional complexity was not considered worthwhile for a plant of this size and with an initial life expectancy of one year. 

Figure 14.7 Decrease in impurity content of 1.5 filter cake volumes suffice to remove the filter cake with the amount of washing liquid impurities stemming from adhering mother used for a displacement washing. The amount phase, is referenced to the filter cake volume. Typically,...

Standalone production sites Intermediate-sized natural gas processing plants that are similarly responsible for a variety of processes involved in removing liquids, impurities, and inert gases from natural gas, including fractionation, sweetening, treatment, dehydration, and compression. 

If a liquid is pure, the breakdown mechanism in it is similar to that in gases. If a liquid contains liquid impurities in the form of... 

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