The purpose of this work is to study the desorption characteristics of water vapor on zeolites saturated with water vapor. Three kinds of zeolite; zeolite 3A, zeolite 4A, and zeolite 5A were used as adsorbent. The desorption experiments with several different temperatures in the range of 90∼150℃ and several different flow rates in the ranges of 0∼0.4 L/min on zeolite bed were carried out. The desorption ability of water vapor was most effective on zeolite 5A among the compared zeolites. The higher the desorption temperature of water vapor was, the faster the desorption velocity was. The desorption ability of water vapor with an air supply was higher than that without an air supply. The most appropriate air flow rate was considered as 0.1 L/min.

The purpose of this work is to study the adsorption and desorption characteristics of acetone vapor and toluene vapor from adsorption tower in the VOCs recovery device. The six kinds of activated carbon with different pore structures were used and the adsorption and desorption characteristics were compared according to pore structure, desorption temperature, and adsorption method, respectively. Adsorption capacity of acetone vapor and toluene vapor by batch method was higher than that by dynamic method. Especially, activated carbon with medium-sized or large pores had more difference in adsorption capacity according to adsorption methods as a result of gradually condensation of vapors on relatively mesopore and large pores. Activated carbons with relatively large pores and relatively small saturated adsorption capacity had excellent desorption ability.

This work is to compare the experiment results by a continuous fixed-bed adsorption of water vapor, acetone vapor, and toluene vapor on zeolite 13X (SAU) and silica-alumina (SAK). SAU and SAK have very different pore structure but similar composition as inorganic adsorbent. The relationship between the equilibrium adsorption capacity and specific pore size range were studied. Adsorption of water vapor was more suitable on SAU than SAK because SAU has relatively more developed pores around 5 Å than SAK in the pore range of 10 ~ 100 Å. Adsorption of acetone vapor was more suitable on SAK than SAU because SAK has relatively more developed pores around 5~10 Å than SAK in the pore range of less than 10 Å. Adsorption of toluene vapor was more suitable on SAK than SAU because SAK has relatively more developed pores in the pore range of 10~100 Å than SAK. Adsorption capacity of the adsorbent was closely related to the surface area generated in the specific pore size region. But it was difficult to distinguish the relationships between adsorption capacity and micro area, and the external surface area of adsorbent.

The purpose of this work is to present the experiment results by a dynamic adsorption of water vapor on pelletized zeolites (ADZ300, ADZ400, and ADZ500) in fixed bed. The breakthrough curves of water vapor with several different concentrations and temperature in the range of 25～45 ℃ on zeolite bed were investigated. In the same conditions, the breakthrough time on ADZ400 and ADZ500 were little longer than ADZ300, and the equilibrium adsorption capacity on ADZ500 was highest. The higher the concentration of water vapor was, the faster the breakthrough time was, and the slope of breakthrough curves showed a tendency to increase. The faster the flow rate of water vapor was, the faster the breakthrough time was relatively, but variations between flow rate and breakthrough time did not have a proportional relationship. The breakthrough curve maintained constant gradient in spite of variation of flow rate in the same concentration. The temperature rise in zeolite bed by adsorption heat was occurred in the early stage of adsorption. After water molecule layers were formed on the surface of zeolite, the temperature was slowly cooled by water vapors continuously flowed in as constant temperature. The greater the concentration of water vapor and adsorption temperature were, the temperature difference in zeolite bed was increased.

This study is to investigate the relationship between pore structures of activated carbons and adsorption characteristics of toluene vapor using dynamic adsorption method. The surface areas of below 10Å in the pore diameter of activated carbons used in this experiment were in the range of 72～93％ of total cumulative surface area and the toluene vapor equilibrium adsorption capacities were in the range of 350～390mg/g. Activated carbons having larger toluene adsorption capacity than the compared activated carbons had relatively pores in the pore diameter range of 7～10Å. Linear relationship between equilibrium adsorption capacity and cumulative surface area was in the diameter range of over 7Å. It was thought that toluene vapor was relatively well adsorbed on surfaces of pores of over 7Å.