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基于恒摩尔流和正规溶液理论建立了O_2-Kr-Xe间歇精馏塔模型,应用BRK法求得各操作条件和返复全回流式操作方式对组分回收率的影响,表明塔板数、上升气量和回流比的增加以及合适的板上持液量都有利精馏操作,通过返复全回流式操作可提高组分的回收率。 相似文献
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基于恒摩尔流和正规溶液理论建立了O_2-Kr-Xe间歇精馏塔模型,应用BRK法求得各操作条件和返复全回流式操作方式对组分回收率的影响,表明塔板数、上升气量和回流比的增加以及合适的板上持液量都有利精馏操作,通过返复全回流式操作可提高组分的回收率。 相似文献
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为研究离子液体在反应精馏中的作用,采用离子液体1-丁基-3-甲基咪唑硫酸氢盐([BMIM]HSO4)作为催化剂,对乙酸和乙醇合成乙酸乙酯的反应精馏流程进行了计算模拟。在确定了参数的酯化反应动力学的基础上,用Aspen Plus软件建立了反应精馏流程,研究了催化剂用量、精馏段理论板数、反应段理论板数、乙醇进料位置、进料摩尔比、持液量及回流比等参数对反应精馏过程的影响。研究结果表明,塔顶乙酸乙酯的质量分数随催化剂用量、精馏段理论板数、反应段理论板数和持液量增大而增大,工艺流程存在最佳回流比以及最佳进料酸醇摩尔比。得到的优化条件如下:离子液体与乙酸摩尔比为1:2.5,进料酸醇摩尔比为4:1,理论塔板数为21块,乙酸和催化剂在第7块理论塔板进料,乙醇在第19块理论塔板进料,塔板持液量0.1L,回流比为4,塔顶乙酸乙酯的质量分数可以达到98.73%。 相似文献
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Aspen Plus软件优化脱除液化气中二硫化物的精馏过程 总被引:1,自引:0,他引:1
利用Aspen Plus软件对以液化石油气(LPG)和二硫化物体系的精馏过程进行了模拟计算。实验得到了达到分离任务时的最小回流比和最小理论塔板数。综合考虑操作费用和设备费用确定了实际的回流比和塔板数。对操作过程进行了优化,塔板数为9,第7块塔板进料,回流比为0.3时,原料中二甲基二硫浓度在400×10^-6以内时,都满足分离要求。 相似文献
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The maximum-profit problem in the operation of a batch distillation column separating a binary mixture is studied. From the objective function made in this paper, such problem can be transformed under special condition, into either maximum-distillate or minimum-time problem. Reflux ratio is chosen as control variable. Digital method is worked out by using optimal control theory to find the condition of optimal operation. In deriving present mathematic model, the liquid hold-up in plates and in condenser as well as the plate efficiency are taken into account. The proposed optimal operation is compared theoretically with the conventional constant reflux ratio and constant overhead composition policies and the results show that the proposed optimal operation can lead to/nuch higher profits. To demonstrate the practical usefulness of the proposed optimal policy, experimental work is carried out in a 4 sieve trays 0.17M diameter batch distillation column with ethanolwater system. Agreement is found between the experimental data and the computed results from present model. 相似文献
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间歇精馏循环全回流操作是一种具有前景的新型操作方式。文中在循环全回流操作的基础上,首次提出了无累积罐循环全回流新操作方式。通过数学模型对其进行模拟,模拟计算比较了新方式、恒回流比间歇操作和塔顶储罐一次全回流操作3种操作方式。模拟结果表明:无累积罐新操作方式的全回流阶段时间由2个因素决定,全回流开始时精馏塔内的浓度梯度情况和精馏塔内持液的平均浓度。随着全回流-全采出操作的进行,后续循环中的全回流阶段的时间增加,全采出阶段时间减少。当进料浓度低时,新操作方式的分离效率比恒回流比方式高26.4%—30.1%,并通过模拟揭示了新操作方式的特点。研究表明:无累积罐循环全回流操作方式是一种新型高效的分离操作。 相似文献
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提出了一种过程始终为全回流操作的间歇精馏新型操作方式,其特征在于沿塔身不同高度设置有多个中间累积罐,操作中整塔始终处于全回流状态,每隔一段时间将下一级储罐内的液体转移至上一级储罐,塔顶储罐内液体作为产品转移到产品储槽。建立了该流程的数学模型并采用Matlab软件进行模拟,当目标产品浓度相同时,新操作方式的可以节省操作时间,在最优化的中间累计罐密集程度下,可节省50%左右,与具体操作参数相关;最后采用乙酸-水二元物系对该操作方式进行了试验验证,且整塔运行稳定易于操作控制。 相似文献
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夹紧区是精馏塔内出现的浓度几乎不变的区域,对于三元物系来说,根据夹紧区在塔内出现的位置可分为:上、中和下加紧区.在无穷板数和任一瞬时釜浓下选择不同的回流比可使分批精馏处于不同夹紧区下操作.文中讨论了三元恒回流比分批精馏过程中夹紧区的演变,在Rayleigh方程的基础上建立了应用夹紧区原理确定多元恒回流比分批精馏最小回流比的方法.该方法并不要求相对挥发度为常数,并且能准确计算顶浓,克服了通常所采用的Underwood公式法的缺陷,为多元分批精馏的简捷设计奠定了基础. 相似文献
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Anuj Narang Amos Ben-Zvi Artin Afacan David Sharp Sirish L. Shah Biao Huang 《Education for Chemical Engineers》2012,7(4):e187-e195
A two-level full factorial design and/or a central composite design are used to optimize the operation of a distillation column by manipulating three variables: the feed flow rate, the reflux ratio and the steam flow to the reboiler. The response variable of interest is a profit function where the objective of this experiment is to examine the effect of each of the three factors and their interactions on this profit function. This is accomplished in a sieve tray type continuous distillation column operated at ambient pressure to separate a methanol–isopropanol mixture. Students were asked to determine the significant variables and the optimal operating conditions for steam rate, reflux ratio and feed rate such that the profit is maximized. As a result, this experiment not only exposes students to an industrially relevant unit operation but it also helps complement the classroom teaching on design of experiment concepts. 相似文献
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Optimal operations of extractive distillation for regular and middle-vase1 batch columns are presented based on a profit function. Detailed models are used for the rigorous dynamic optimization considering all operational decision variables, including reflux ratio, solvent feed rate, heat duties, and possible product withdrawals during the process. Optimal feed distribution and stream configuration at the middle section of the middle-vessel column are investigated. Separation of a minimum boiling azeotropic binary mixture (acetone and methanol using water as solvent) involving different separation duties and feed compositions is presented as a case study. The pereformanance of the middle-vessel column is signicantly influenced by the middle-section stream configuration, with the best profit when the stream configuration is allowed to vary during the operation. The optimal operating policy for the middle-vessel column involved the feed being charged mainly to the reboiler still with low holdup in the middle vessel during the operation. 相似文献