【作者】 孙宗伟；

【导师】 匡国柱；

【作者基本信息】 大连理工大学 ， 化学工程， 2008， 硕士

【摘要】 精馏过程广泛地用于石油、化工和天然气加工工业中,是当代工业应用最广的分离技术,同时也是能量密集型单元操作之一。在当今能源紧缺的情况下,对精馏过程的节能研究,就显得十分重要。热偶精馏是用主塔和副塔组成的复杂塔代替常规精馏塔序,由于其可逆混合特性,它可以降低过程中的不可逆有效能损失,可提高热力学效率,在热力学上是较理想的系统结构。即可节省设备投资,又可节省能耗,具有极为诱人的发展前景,因此吸引了许多来自学术界和工业界的目光。对于三元以上混合物系的多组分分离,热耦合精馏塔较传统分离序列有较显著的节能优势。本文通过模拟热耦合精馏塔,获得了不同进料条件对中间组分在预分馏塔塔顶产品流股中的分配比参数最优值的影响规律,进而为热耦合精馏塔的设计和操作提供了依据。文章采用Aspen Plus软件中RadFrac模型,在三塔模型的简洁法计算提供的初值基础上,对三组元混合物的热耦合分离作了严格的模拟研究。本文以三元混合物系分离过程为例,对两种常规分离序列与三种热耦合精馏序列进行了对比研究,考察了不同分离指数和不同进料组成条件下常规分离序列和热耦合精馏过程的热能消耗及其热力学效率。结果表明,热耦合精馏序列较常规精馏序列节能10%—50%,且具有更高的热力学效率,完全热耦合精馏过程具有最高的热力学效率。而且当分离指数接近1和分离指数小于1时,热耦合分离序列精馏过序列的节能效果更为显著,三元混合物的中间组分含量越高,热耦合精馏的节能效果越显著。更多还原

【Abstract】 Distillation, which is presently being applied to the industrial level in crude oil refine, chemical engineering and natural gas processing, is one of the most widely used separation technology in present industry and almost the largest energy consumption unit operation. Therefore, it is very important to have the investigation of the energy saving in the distillation process under the circumstance of energy source deficiency.Thermally coupled distillation column consists of two towers, and it is a kind of complex columns. It has much less irreversible energy loss and higher Thermodynamic Efficiency in distillation process because of the reversible mixed property. It both conserves energy and saves the equipment investment, but also has other merits, thus it has the extremely attractive prospects for development. Therefore, it attracts many eyes from academic and industry circles.Thermally coupled distillation columns can reduce energy consumption and capital investment comparing to conventional distillation consequences for separation of ternary and multi components mixtures with the application of Aspen Plus software, rigorous simulations were firstly performed to the thermally coupled distillation columns for ternary hydrocarbon mixture separation, focusing on how middle component fractional recovery influences overall expense under the conditions of different feed compositions and diverse relative volatilities.Thermodynamic efficiency calculations and energy requirements have been performed for the separation of ternary mixtures of hydrocarbons in both 2 kinds of conventional and 3 kinds of thermally coupled distillation sequences.When ternary mixtures were considered, energy savings achieved in the thermally coupled distillation sequences were between 10 and 50% in comparison to the two conventional distillation sequences. Regarding thermodynamic efficiency, thermally coupled distillation sequences presented the highest values in almost all of the cases considered. When the Ease of Separation Index is around 1 or less than 1, When the Ease of Separation Index is around 1 or less than 1, thermally coupled distillation columns are better. And when the middle component composition is higher, thermally coupled distillation columns is better.更多还原