Absorption temperature

Absorption. Oil absorption is another process used for recovery of LPG and natural gas Hquids from natural gas. Recovery is enhanced by loweriag the absorption temperature to —45°C and by keeping the molecular weight of the absorption oil down to 100. Heat used to separate the product from the absorption oil contributes to the cost of recovery. Therefore, this process has become less competitive as the cost of energy has iacreased. A simplified flow diagram of a typical oil-absorption process is shown ia Figure 2. 

K. T. V. Grattan, R. K. Selli, and A. W. Palmer, Fiber-optic absorption temperature sensor using fluorescence reference channel, Rev. Sci. Instrum. 57, 1175-1178 (1986). 

The absorption curves in Fig. 2.4a were analyzed by a linear fitting to the JMAK equation from which the reaction rate constant, k, and the reaction order,p, can be determined. The values of the reaction order p are listed in Table 2.4. At the lowest absorption temperature of 250°C, the p parameter is close to 2, and then it decreases to about 1, remaining close to this value at all the other temperatures. The different values of the reaction order suggest that different mechanisms are controlling the rates at various temperature ranges of absorption. It can be seen from Table 2.3, that the value of 2 (1.83 in Table 2.4) suggests that the transformation of Mg to... 

In summary, one can say that NaAlH is one of the most extensively researched hydride. Although the desorption/absorption temperatures and time durations for a... 

The Active Magnesia Process (24) can be viewed as the gas phase equivalent of the Wellman-Lord (to be discussed below) in that it serves primarily to concentrate the SO2 values in the combustion effluent to a suitable concentration for feed to an oxidative process yielding sulphuric acid. The absorption temperature, however, is quite low compared with typical combustion effluent temperatures. 

Solution processes for removal of SO2 from effluent gas streams normally require lower absorption temperatures than do gas phase techniques. Thus, of the four listed in Table IV only the Molten Salt Method has the capability of accepting high temperature flue gas without cooling. In all but one of the cases, elemental sulphur is the end product and in the single instance of the Ammoniacal Solution Process, sulphur is a coproduct with ammonium sulphate. This process has been extensively examined and developed in a number of countries, and is chemically interesting because of the unusual redox reaction that is suspected to take place between the products of air oxidation of SO2 absorbed in ammonia solution. Both products, sulphur and ammonium sulphate, are normally saleable commodities. 

Absorption of the nitrogen oxide components (NOx) of the process gas stream is conducted in a sieve tray-type absorption column. This tower contains 59 sieve trays, of which the top 45 trays contain herringbone cooling coils to remove heat of reaction/dilution and maintain low absorption temperatures. 

The absorption column is required to absorb nitrous reaction gases thus producing 80% (wt.) nitric acid product (dissolved impurity-free basis). This is achieved by the countercurrent absorption of the nitrogen oxide components from the reaction gas into a water/weak-acid media. The column specification requires an operating pressure of 950 kPa and an absorption temperature in the range of 10°C to 65°C. 

In order to improve the kinetics of the Li-N-H system, Xie et al. [96] prepared Li2NH hollow nanospheres by plasma metal reaction based on the Kirkendall effect. The special nanostructure showed significantly improved hydrogen storage kinetics compared to that of the Li2NH micrometer particles. The absorption temperature decreased markedly, and the absorption rate was enhanced dramatically because... 

The Gesellschaft fiir Stickstoffdiinger, at Westerregeln, add anything up to 10 per cent. CaCU to the powdered carbide, the absorption temperature of the N being only 700° C. The product, containing 20 per cent. N, 45 per cent. Ca, 19.5 per cent. C, 6.5 per cent. Cl, and 9 per cent, impurities, is put on the market under the name Stickstoffkalk. ... 

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