## 3 Results and Discussion  
### Analysis of Influence of Diffusion Resistance  
The essential condition of successful usage of the adsorbents is the determination of the scope of the process behaviour, where external diffusion resistance is absent. For that, the experimental research was preliminarily conducted on the laboratory unit to determine the linear velocity of gas supply, providing the absence of the external diffusion. According to the data in Figure 2, it is visible that when the linear velocity of the gas flow in the adsorber increases, both at the contact time of 0.6 s and at the contact time of 1.1 s, the adsorption capacity of the sample increases monotonically. At the velocity equal to \(\sim\)0.20 m/s, the adsorption capacity stops changing, which indicates the fact that external diffusion (mass transfer) does not influence the adsorption process any more. Generally, the influence of the supply of the substance from the flow to the external surface of the adsorbent granules is practically excluded at the flow rate of 0.25 m/s [1,8]. To correctly interpret the experimental data, the experiment must be conducted in similar conditions and with the same ingoing water concentration. The experimental data, obtained at a temperature of \(\sim\)18 \({}^{\circ}\)C in the saturator, were taken into account, which allowed providing \(14.6\div 15.5\) g/m\({}^{3}\) of the water content in the flow at the entrance to the adsorber. Hydrodynamical similarity-homogeneity of the layer filling (constant bulk density of the adsorbent)-was also provided. An important characteristic of the used sorbent was the temperature of its regeneration. Earlier, in [30] the adsorption characteristics of the prospective adsorbent based on aluminium oxide were presented at different temperatures of its regeneration (110 \({}^{\circ}\)C, 150 \({}^{\circ}\)C, 270 \({}^{\circ}\)C). It was shown that even after desiccant regeneration at 110 \({}^{\circ}\)C, its dynamic capacity by water exceeded the values, obtained for the foreign analogue, and the maximal values of the dynamic capacity were obtained when using the training temperature of  
Figure 2: Dependence of the dynamic capacity of the prospective aluminium-oxide adsorbent on the linear velocity of the gas flow in the adsorber of the laboratory unit at different time contacts: 1.1 s and 0.6 s (conditions: the saturator temperature is 18 \({}^{\circ}\)C, pressure is 0.1 MPa). 270 \({}^{\circ}\)C. In this connection, before conducting the mentioned tests, the samples Al\({}_{2}\)O\({}_{3}\) were subjected to thermal treatment at 270 \({}^{\circ}\)C for 2 h in the inert gas ambient (nitrogen). Before tests, the zeolite was trained at a temperature of 350 \({}^{\circ}\)C for two hours in the inert gas ambient (nitrogen). All the experiments presented hereafter were conducted on the pilot installation for two adsorbents: the prospective aluminium oxide adsorbent (Al\({}_{2}\)O\({}_{3}\)) and the commercial foreign adsorbent, based on the zeolite (NaX). The grain dimensions of the aluminium oxide adsorbent were: diameter-3.55 mm, height-5.2 mm; NaX sizes: diameter-4.2 mm, height-4.4 mm. Thus the equivalent adsorbent diameter (proportional to the ratio of the grain to its external surface) was approximately the same and amounted to d\({}_{\rm e}\) = 4.0 \(\div\) 4.2 mm. Effect of Layer Height on the Adsorption Characteristics of the Samples Al\({}_{2}\)O\({}_{3}\) and NaX  
The results (Table 1) were obtained at a gas consumption rate of 25 L/min (gas velocity was 0.21 m/s), pressure of 0.1 MPa and water concentration at the entrance of 14.6 \(\div\) 15.5 g/m\({}^{3}\). To compare the results, the layer retention time was reduced to 15 g/m\({}^{3}\), which corresponded to 100% of humidity at 18 \({}^{\circ}\)C.  
When the height of the adsorbent layer increases, its adsorption capacity also increases (Table 1). The protective power time of the layer increases at the expense of the increase in the dynamic capacity and the adsorbent volume.