tailieunhanh - Thermodynamics Interaction Studies Solids, Liquids and Gases Part 4

Tham khảo tài liệu 'thermodynamics interaction studies solids, liquids and gases part 4', kỹ thuật - công nghệ, cơ khí - chế tạo máy phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | 170 Thermodynamics - Interaction Studies - Solids Liquids and Gases Fig. 1. Calorimeter immersion scheme Tian type. l Sensors System 2 Sample cell 3 Sample 4 Heat Sink 5 Heat resistance for calibration 6 Insulation jacket 7 Output of resistance to power supply 8 Output of sensors system to interface multimeter. Fig. 2. Thermogram obtained for the immersion of an activated carbon pellet ore CAP in benzene Thermodynamic of the Interactions Between Gas-Solid and Solid-Liquid on Carbonaceous Materials 171 Figure 2 shows a typical thermogram obtained for the immersion of an activated carbon pellet ore CAP in benzene. It can be seen in the range of 0 to 500 seconds the baseline obtained which illustrates the heat balance and low noise level in the calorimetric signal. Table 1 shows the values of surface properties obtained by immersion calorimetry for this same sample two samples obtained by the modification of the CAP. Sample Eo kJ mol Wo cm3 g Sbet m2 g CAP 1248 CAPRED 1089 CAPN65 1253 Table 1. Surface properties obtained for three activated carbons by gas adsorption The sample CAPRED is a modification of CAP obtained by heating the same until 1373 K under nitrogen for 3h. CAPN65 sample is a sample obtained by modification of CAP through the impregnation of CAP with 65 HNO3 and heating it to 473 K for 2 hours. As shown in Table 1 the modification with HNO3 and 65 did not produce a significant change in the surface properties of the sample. This behavior is attributed to the low temperature at which it made the change which did not affect the porous structure of the solid. The modification to 1373K nitrogen affected the pore structure of the solid reducing the volume of micropores and consequently the surface area there of in Figure 3 shows the isotherms of nitrogen at 77 K for these three samples. Fig. 3. Nitrogen adsorption isotherms at 77 K for the three carbons under study The isotherm can be observed further that the sample has CAPRED