NaY沸石分子筛在VOCs处理中的应用

为深入研究分子筛吸附VOCs的性能，采用固定床动态吸附法，对NaY分子筛吸附3种典型VOCs的性能进行了探究，考察了吸附温度、湿度、进气浓度和吸附质物理性质对吸附容量的影响，并探讨了NaY分子筛的循环使用性能；通过Yoon-Nelson模型，从吸附动力学角度，对单组分VOCs吸附穿透曲线进行了拟合。结果表明：NaY分子筛对3种VOCs的吸附饱和时间分别为丙酮355 min，邻二甲苯320 min，乙酸乙酯220 min；相对应的平衡吸附容量分别为丙酮176 mg·g⁻¹，邻二甲苯196 mg·g⁻¹，乙酸乙酯185 mg·g⁻¹。NaY分子筛对VOCs吸附能力排序为邻二甲苯>乙酸乙酯>丙酮。温度由303 K升至328 K时，3种VOCs吸附容量均分别下降，邻二甲苯下降3.66%，乙酸乙酯下降2.87%，丙酮下降10.0%；VOCs相对湿度为30%时，吸附容量显著降低；进气浓度为660 mg·m⁻³时，出现吸附交叉的现象；NaY分子筛具有较好的循环使用性；吸附容量与沸点、分子质量存在正相关关系；3种VOCs在NaY分子筛固定床的吸附速率排序为乙酸乙酯>邻二甲苯>丙酮。Yoon-Nelson模型能够较好地模拟NaY分子筛吸附不同VOCs的过程，为分子筛的工业应用提供了参考。

Application of NaY zeolite molecular sieve in VOCs treatment

In order to further study the VOCs adsorption performance on zeolite, the adsorption performance of three typical VOCs on NaY molecular sieve was studied by fixed bed dynamic adsorption method. The effects of adsorption temperature, humidity, concentration of inlet and physical properties of adsorbent on adsorption capacity were investigated, as well as the recycling property of NaY molecular sieve. The adsorption penetration curve of single-component VOCs was fitted with the Yoon-Nelson model from the perspective of adsorption kinetics. The results showed that the saturated adsorption times of acetone, o-xylene, and ethyl acetate on NaY molecular sieve were 355, 320 and 220 min, respectively, and their corresponding equilibrium adsorption capacities were 176, 196 and 185 mg·g−1, respectively. The adsorption capacity of VOCs on NaY was in the order of o-xylene>ethyl acetate>acetone. When the temperature increased from 303 K to 328 K, the adsorption capacities of three VOCs decreased by 3.66%, 2.87% and 10.0% for o-xylene, ethyl acetate, and acetone, respectively. At VOCs relative humidity of 30%, its adsorption capacity decreased significantly. Adsorption curve intersection occurred when inlet concentration was 660 mg·m−3. NaY molecular sieve had a good recycling performance. A positive correlations were obseved between the adsorption capacity and the physical properties of VOCs such as boiling point, molecular weight. The order of adsorption rate of three VOCs on NaY was as follows: ethyl acetate>o-xylene>acetone. The Yoon-Nelson model parameters could accurately predict VOCs adsorption behavior of NaY molecular sieve in a fixed bed reactor. It can provide basic data for industrial application of molecular sieve.