工况条件对活性炭吸附-脱附CS_(2)的影响

Study on the adsorption and desorption of CS_(2) on activated carbon under different operating conditions

CS_(2)是一种典型的工业化学毒物,对人体和环境危害极大,目前常用去除方法为活性炭吸附。笔者采用动态吸附装置研究活性炭对CS_(2)吸附-脱附性能,考察温度、气体流速、CS_(2)浓度和气流湿度对活性炭吸附-脱附CS_(2)的影响。结果表明:活性炭对CS_(2)吸附量和残存量随着吸附温度的升高而降低。当流速小于625 mL/min,随着流速的增加,活性炭对CS_(2)吸附量增加,残存量降低;当流速大于625 mL/min,随着流速的增加,活性炭对CS_(2)的吸附量降低,残存量增加。活性炭对CS_(2)吸附量随着CS_(2)质量浓度增加而增加。但当CS_(2)质量浓度小于1 643 mg/m^(3)时,随着质量浓度的增加,残存量增加;当CS_(2)质量浓度大于1 643 mg/m^(3),随着质量浓度的增加,残存量降低。随着湿度的增加,活性炭对CS_(2)吸附量降低,残存量增加。综合上述研究结果可以得出:吸附温度、气体流速、CS_(2)浓度和湿度等工况条件对活性炭CS_(2)吸附量和残存量均有较大影响,其中CS_(2)浓度对吸附的影响最大,而脱附残存量主要与吸附温度和CS_(2)浓度有关。为实现活性炭高效吸附和脱附,最佳工艺条件为:干燥状态下,吸附温度25℃,流速小于625 mL/min, CS_(2)质量浓度为1 643 mg/m^(3)。

CS_(2) is a common solvent and chemical raw material, with high toxicity, high volatility, low boiling point, flammability and explosive characteristics. It is easy to be distributed to the environment duringits production and service, which is extremely harmful to the human body and environments. In order to control CS_(2) emissions, Chinese Regulation requires CS_(2) content to be lower than 10 mg/m^(3) in current industrial exhaust emissions and the maximum allowable concentration in workshops. Using activated carbon to remove CS_(2) is not only low cost, easy to operate, but also has better adsorption performance. However, external operating processes, such as flow rate, temperature, concentration, and humidity, seriously affect the adsorption-desorption performance of activated carbon. Therefore, it is necessary to systematically investigate the effects of different operating process conditions on the adsorption and desorption of CS_(2) by activated carbon. A dynamic device was used to study the adsorption-desorption performance of activated carbon on CS_(2) and the effects of temperature, flow rate, concentration, and humidity on the adsorption-desorption of CS_(2) by activated carbon were investigated. The experimental results showed that the activated carbon adsorption quantity and residual quantity for CS_(2) decreased with the increase of adsorption temperature. When the flow rate was less than 625 mL/min, with the increase of flow velocity, the activated carbon adsorption quantity of CS_(2) increased, the residual quantity reduced. When the velocity was greater than 625 mL/min, with the increase of flow velocity, the activated carbon adsorption quantity of CS_(2) was reduced and the residual stock increased. The adsorption quantity of activated carbon to CS_(2) increased with the increase of CS_(2) concentration, but when the concentration of CS_(2) was less than 1 643 mg/m^(3), the residual quantity increased with the increase of CS_(2) concentration. When the concentration of CS_(2) was greater than 1 643 mg/m^(3), the residue quantity decreased with the increase of CS_(2) concentration. With the increase of humidity, the activated carbon adsorption quantity of CS_(2) was reduced and the residual quantity increased.