CAJ | 학술논문

运用Langmuir等温线方程和理想吸附溶液理论(IAST)两种方法计算了SAPO-34在混合气体中的单个物种表面浓度，并对比了计算值与实验值的吻合程度。考察了两个二元混合体系，分别为80 oC的甲醇和二甲醚以及25 oC的二甲醚和乙烯混合气，发现IAST计算值在实验压力范围内均与实验结果吻合；但是Langmuir理论计算值仅在酸性位覆盖率低于1/3时与实验值吻合较好，随着压力增加严重偏离实验值，而且Langmuir理论不能描述随压力增加低饱和吸附量物种覆盖率降低的现象。因此，针对包含不同饱和吸附量组分的混合气， Langmuir理论仅适用于描述表面浓度低时的反应动力学，当表面浓度高时应该采用IAST方法。
운용Langmuir등온선방정화이상흡부용액이론(IAST)량충방법계산료SAPO-34재혼합기체중적단개물충표면농도，병대비료계산치여실험치적문합정도。고찰료량개이원혼합체계，분별위80 oC적갑순화이갑미이급25 oC적이갑미화을희혼합기，발현IAST계산치재실험압력범위내균여실험결과문합；단시Langmuir이론계산치부재산성위복개솔저우1/3시여실험치문합교호，수착압력증가엄중편리실험치，이차Langmuir이론불능묘술수압력증가저포화흡부량물충복개솔강저적현상。인차，침대포함불동포화흡부량조분적혼합기， Langmuir이론부괄용우묘술표면농도저시적반응동역학，당표면농도고시응해채용IAST방법。
The use of the Langmuir isotherm for competitive adsorption and the use of ideal adsorbed solution theory (IAST) for calculating the surface concentrations of adsorbed species on a SAPO-34 catalyst exposed to a gas mixture were compared with experimental measurements. Two binary mixtures, namely, methanol and dimethyl ether (DME) at 80 °C and DME and ethene at 25 °C were used. IAST gave good agreement in the whole range of experimental concentrations, while Langmuir theory only gave good agreement up to when one-third of the acid sites were covered and then showed increasingly large deviations with increased pressure, and it failed to capture the phenomenon that the concentration of an adsorbed species with a smaller saturation adsorption capacity would de-crease with increased pressure. Thus, for reactions of gas mixtures whose components have differ-ent saturation adsorption capacities, Langmuir theory can only be used for the reaction kinetics when the surface concentrations are quite low, and IAST should be used when the surface concen-trations are high.