低碳燃料醇共沸脱水技术的数模计算及验证

MATHEMATICAL MODELLING AND VERIFYING TESTS OF AZEOTROPIC WATER-REMOVAL TECHNIQUE FOR HIGHER ALCOHOLS

对低碳燃料醇环己烷共沸蒸馏脱水三塔(甲醇塔、共沸塔和脱水塔)流程中的各塔进行了数模计算,并用小型筛板塔进行验证。模型包括Wilson、NRTL和UNIQUAC。沿塔身十六套552个组分计算值与实测值的平均偏差为约0.8—0.9%(摩尔);107个温度点的平均偏差约2℃(以UNIQUAC最好)。说明采用的数模计算方法,包括数模计算本身及所采用的平衡模型参数及基础物性参数都是可靠的,可满足进一步工程设计的需要。

Mathematical modelling and verifying tests with a small sieve-plate column were conducted for simulating methanol column, azeotrope column and water-removal column which were to be used for removal of water from higher alcohols with cyclohexane as a azeotrope former. Wilson,NRTL and UNIQUAC models were chosen for modelling. The average deviations of calculated values from experimental values for 16 sets of data along the column were 0.8-0.9%(mol) for 552 points of component and 2℃ for 107 points of temperature. The calculating results indicated that the UNIQUAC model is the best one. These results also showed that the modelling method used and the vapor liquid equilibrium data as well as the physical constants used for modelling were all reliable and satisfactory for the design of distillation column.