Abstract
This paper presents the results of performance tests of various kinds of adsorbents by static and dynamic adsorption methods to select the optimum deodorant (adsorbent) for Hydrogen sulfide gas (H2S).
In the performance test by the static adsorption method, the amounts of H2S adsorbed of 15 different kinds of adsorbents (physical or chemical adsorbents) were measured.
The amounts adsorbed by adsorbents with high adsorption ability were 0.042-0.043 g/g at 30°C and an equilibrium pressure of 50 mmHg. The equilibrium adsorption amount adsorbed by chemical adsorbents were not higher when compared to physical adsorbents. The type of H2S adsorption isotherm in all of the adsorbents fit in Freundlich's adsorption isotherm. All of adsorbents may be used repeatedly when judged from the values of heat of adsorption. The relationships between the equilibrium adsorption amount and specific area, pore volume, mean pore radius, pH were studied, the slight correlation was observed between the mean pore radius and the equilibrium adsorption amount.
In the performance test of the dynamic adsorption method, we examined four kinds of adsorbents selected from the above-mentioned 15 kinds of adsorbents. The removal efficiency and the breakthrough time were used as the indexes.
In the removal efficiency performance test, the removal efficiency is related to the equilibrium adsorption amount measured by the static adsorption method.
However, in the 10% breakthrough time performance test (experimental conditions: inlet gas concentra-tion 100 ppm, bed height 7 cm, gas linear velocity 0.4 m/sec, contact time 0.147 sec, gas temperature 25°C, relative humidity 50%), the breakthrough time of the adsorbent, which was third in equilibrium adsorption amount (0.042g/g at 30°C, 50 mmHg), was only 34 min, while the breakthrough time of the adsorbent, which was eighth in equilibrium adsorption amount (0.034 g/g at 30°C, 50 mmHg), was 202 min, which was about 6 times longer than that for the first one.
These results suggest that the performance test only by the static adsorption method is insufficient and that the breakthrough time test by the dynamic adsorption method is important.
