低共熔溶剂对乙烷和正丁烷的吸收性能研究

Study on the Absorption Properties of Ethane and n-Butane in Deep Eutectic Solvents

通过开展乙烷和正丁烷在分子型低共熔溶剂癸酸-油酸(1∶2)中的稳态和动态吸收实验研究,考察低共熔溶剂对轻烃VOCs的吸收性能,为解决石化行业VOCs深度治理难的问题提供一种新方法。采用饱和溶解法考察了乙烷和正丁烷在癸酸-油酸(1∶2)中的溶解性能,采用动态鼓泡吸收法考察了乙烷和正丁烷在癸酸-油酸(1∶2)中的吸收效率和再生性能。饱和溶解实验中,乙烷和正丁烷在低共熔溶剂中的溶解度随温度降低、压力升高而升高,其中15℃条件下,乙烷和正丁烷在癸酸-油酸(1∶2)吸收的Henry系数分别为2.073 MPa和0.133 MPa,达到与离子液体相当或更高水平,由此证明癸酸-油酸(1∶2)对轻烃具有较高的吸收容量;动态鼓泡实验中,VOCs去除率随模型气流量降低、VOCs浓度增大而升高,温度对动态吸收效率的影响是溶解度和分子热运动的双重作用结果,在相同条件下正丁烷相比乙烷表现出更高的去除率,其中在20℃、正丁烷浓度10000μmol/mol、气体流量30 mL/min的动态吸收条件下,正丁烷去除率可达到99.99%以上,且再生过程中低共熔溶剂对正丁烷的动态去除率无明显下降,表明癸酸-油酸(1∶2)对轻烃具有优异的吸收效率和良好的再生性能。上述研究成果证明了低共熔溶剂作为吸收剂可实现轻烃VOCs的深度回收,可为用于石化行业油气回收或VOCs治理的基础研究及工业化应用提供理论和数据支撑。

Through the steady state and dynamic absorption experiments of ethane and n-butane in molecular eutectic solvent capric acid-oleic acid(1∶2),the absorption performance of low eutectic solvent to light hydrocarbon VOCs was investigated,which provided a new method to solve the difficult problem of VOCs treatment in petrochemical industry.The solubility of ethane and n-butane in capric acid-oleic acid(1∶2)was investigated by saturated solution method,and the absorption efficiency and regeneration performance of ethane and n-butane in capric acid-oleic acid(1∶2)were investigated by dynamic bubble absorption method.In the saturation dissolution experiment,the solubility of ethane and n-butane in low eutectic solvent increased with the decrease of temperature and the increase of pressure.Under the condition of 15℃,the Henry coefficients of ethane and n-butane absorption in capric acid-oleic acid(1∶2)were 2.073 MPa and 0.133 MPa,respectively,which reached the same level or higher than that of ionic liquid.It was proved that capric acid-oleic acid(1∶2)had a high absorption capacity for light hydrocarbons.In the dynamic bubble experiment,the removal rate of VOCs increased with the decrease of model gas flow rate and the increase of VOCs concentration.The influence of temperature on the dynamic absorption efficiency was the result of the dual action of solubility and molecular thermal motion.Under the same conditions,n-butane showed a higher removal rate than ethane.Under the dynamic absorption conditions of 20℃,n-butane concentration of 10000μmol/mol and gas flow rate of 30 mL/min,the n-butane removal rate can reach more than 99.99%,and the dynamic removal rate of n-butane by low eutectic solvent did not decrease significantly during the regeneration process.The results showed that capric acid-oleic acid(1∶2)had excellent absorption efficiency and good regeneration performance for light hydrocarbons.The above research results proved that the low eutectic solvent as an absorber can realize the deep recovery of light hydrocarbon VOCs,which can provide theoretical and data support for the basic research and industrial application of oil and gas recovery or VOCs treatment in the petrochemical industry.