共查询到17条相似文献,搜索用时 62 毫秒
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提出了一种新的三塔精馏工艺用于合成甲醇的精制过程。在采用差压双效精馏实现系统内热集成的方案中,新工艺将加压塔塔顶蒸汽分为两部分,一部分作为预塔再沸器的供热源,其余部分作为常压塔再沸器的供热源,实现了供热蒸汽的完全热集成。同时将常压塔塔底出料的高纯软水和加压塔塔底部分含盐水回用为预塔萃取水,实现了系统内工艺软水的完全集成,既节约了工艺软水,又减少了系统的废水排放量。运用Aspen Plus定态模拟方法,对Lurgi工艺,文献中提到的W-C工艺和新的Z-W工艺进行对比研究,研究结果表明Z-W工艺比现有Lurgi工艺节约能量21.4 %,节约软水100 %,减少废水排出量81.4 %;比文献中W-C工艺节约能量11.7 %,节约软水100 %,减少废水排出量68.5 %。 相似文献
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针对现苯-甲苯塔热集成工艺的不足,提出了苯-甲苯分离的双效热集成节能新工艺。采用化工模拟软件Aspen one V7.2,选取Peng-Robinson热力学模型,分别对苯-甲苯分离的传统精馏流程、苯-甲苯塔热集成精馏流程及苯-甲苯塔双效热集成精馏流程进行了模拟计算和分析。结果表明,在产品质量和收率相同的条件下,采用双效热集成精馏新工艺和现工业装置苯-甲苯热集成精馏工艺相比,其总加热量降低了13.4 MW,节能率40.22%,节能效果显著;所增加的甲苯塔第一效精馏塔操作真空度不高,塔顶蒸汽可采用空冷器冷却,其余设备和现有苯-甲苯塔热集成精馏工艺相同,装置改造投资少,容易推广实施。 相似文献
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我公司20kt/a甲醇三塔双效精馏工艺系统于2004年底开车,当月即采出符合GB338-92的优质产品。通过对精馏系统的试车、开车和生产操作经验进行总结发现,保证三塔(预塔、加压塔、常压塔)的物料、气液、热量平衡是精馏系统稳定操作的基础,预精馏塔的操作稳定与否更是关系到精馏系统能否正常运行的关键。[第一段] 相似文献
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《中国石油和化工标准与质量》2016,(12)
本文主要是针对三塔双效精馏工艺和四塔双效精馏新工艺进行研究,通过对改进的三塔双效精馏工艺进行了解可知,加压塔产生的蒸汽可以作为常压塔的热源来使用,能够提升使用的效果。四塔双效精馏新工艺是三塔双效精馏工艺的升级版,在使用流程中增加了加压塔功能,有利于得到精甲醇产品,能够在塔底进行污水的排放。通过对两种新工艺的稳态进行模拟,需要对这两种新工艺的使用方法进行了解,能够展现出换热器两侧的温差,有利于换热器的正常工作。 相似文献
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基于对醋酸甲酯与甲醇二元共沸特性的分析,提出热集成变压精馏分离醋酸甲酯和甲醇的工艺. 利用Aspen Plus软件对该分离过程进行模拟,以NRTL活度系数方程为物性计算方法,其二元相互作用参数由气液相平衡数据回归,分析了加压塔和常压塔的理论板数、进料位置及回流比对分离效果的影响,并进行了能耗比较. 结果表明,该工艺能很好地分离醋酸甲酯和甲醇,较佳的工艺条件为:加压塔操作压力909 kPa,理论板数32,第21块板进料,回流比4.2,塔釜醋酸甲酯纯度99.8%;常压塔操作压力101 kPa,理论板数30,第20块板进料,回流比4.6,塔釜甲醇纯度99.0%. 与常规变压精馏相比,热集成变压精馏可节能达45.8%;与以水为萃取剂的萃取精馏分离工艺相比,热集成变压精馏分离工艺更适合醋酸甲酯与甲醇体系的分离. 相似文献
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针对常规变压分离碳酸二甲酯和甲醇工艺能耗较高的问题,文中提出了分离该体系的热集成变压精馏新工艺。采用Aspen Plus软件及Wilson物性方法,以年度总费用最小为目标对两塔的塔板数、进料位置、回流比等参数进行了优化,结果为总塔板数常压塔24块,加压塔11块;进料位置为常压塔第6块,加压塔第7块;回流比常压塔为1.5,加压塔为1.2。加压塔塔顶和常压塔塔底的温差为74℃,满足完全热集成的条件。完全热集成变压分离该工艺总能耗成本为0.114×106美元/a,年度总费用为0.185 8×106美元/a,相比于常规变压精馏工艺,完全热集成工艺可节省能耗约46%,年度总费用节省约39.2%。模拟结果表明:碳酸二甲酯和甲醇产品纯度(质量分数)可达到99.5%,满足分离要求。完全热集成变压精馏工艺可以经济、有效地分离该共沸物。 相似文献
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Juntao Zhang Shengrong Liang Xiao Feng 《Chemical Engineering and Processing: Process Intensification》2010
Crude methanol distillation is an energy-intensive separation process and contributes significantly to the cost of methanol production. Although a number of energy-efficient distillation systems have been proposed, there is potential for energy savings in methanol distillation. To further reduce the energy consumption of methanol distillation, a novel five-column multi-effect distillation process is proposed in this work, which is essentially an improved version of an existing four-column scheme. The four-column scheme is made up of a pre-run column, a higher-pressure column, an atmospheric column and a recovery column. The new five-column scheme adds a medium-pressure column after the original higher-pressure column. In this way, the load of the original higher-pressure and atmospheric columns can be decreased by about 30%. The five-column arrangement creates a multi-effect distillation configuration involving efficient heat integration between higher-pressure and medium-pressure columns, atmospheric and recovery columns, and recovery and pre-run columns. Steady-state process simulation results indicate that temperature differences at two sides of each heat exchanger are appropriate, allowing effective heat transfer. Economic analysis shows that the energy consumption of the five-column scheme can be reduced by 33.6% compared to the four-column scheme. Significant savings in operating costs can therefore be achieved, resulting in an economically viable process for methanol distillation. 相似文献
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研究了包含甲醇、水、丙二醇和二丙二醇四组分混合物的分离问题,针对混合物的特征和分离要求,提出四产品Kaibel隔壁精馏塔的分离工艺,并利用Aspen Plus软件对Kaibel塔进行设计与节能分析。首先,设计了分离四组分混合物的三塔精馏流程(TCD)和热集成三塔精馏流程(HTCD);其次,开展了四产品Kaibel塔分离四组分混合物的模拟研究,取得了满足分离要求的塔设计参数;最后,采用能量衡算和㶲损失分析相结合的方法,对Kaibel塔的用能特征进行了分析和比较。研究表明,与热集成三塔精馏流程相比,四产品Kaibel塔在操作费用方面不占优势,但在设备投资方面具有明显优势,可以实现在一个塔内四组分的分离,总㶲损失可降低9.41%。 相似文献
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A process composed of a fixed-bed and a distillation column with a side withdraw, mainly methanol, is developed to hydrolyze methyl acetate (MA) as a typical byproduct in polyvinyl alcohol (PVA) and pure terephthalic acid (PTA) factory. The process is simulated by employing the equilibrium stage model RadFrac and plug flow model Rplug in Aspen Plus. Experiments are also carried out in a lab-scale to evaluate the process. The results show that at the molar ratio of water to methyl acetate about 4.0-5.0 in the feed stream and the volume ratio of distillate to feed MA above a critical value, the side product contains more than 80% (by mass) (MeOH) and less than 2% (by mass) MA, while the bottom contains more than 46% (by mass) acetic acid (HAc) and less than 0.5% (by mass) methanol with almost complete conversion of MA. Compared with the old catalytic distillation process we proposed before, this process can cut down 47.6% energy consumption and a distillation column. 相似文献
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精馏作为过程工业中最重要和最常用的分离手段, 是耗能最大的单元操作。精馏塔一般从再沸器输入热量, 从冷凝器取走热量, 利用某些塔高温位的冷凝热加热其他塔的再沸器, 并将单塔节能技术与过程集成相结合, 实现塔系的热集成, 可充分挖掘系统内部的节能潜力, 达到减少公用工程消耗的目的。本文通过对某化工厂的苯乙烯装置精馏塔系的分析, 通过各个塔的温焓图之间的关系, 提出了精馏塔系内部热集成的措施, 包括直接热集成、调压热集成和双效精馏与间接热集成耦合等3种方案。对于后两个热集成方案, 采用Aspen Plus模拟改造后精馏塔的变化并验证了方案的可行性。结果表明, 苯乙烯装置采用该热集成措施能明显节省高品位蒸汽的消耗, 降低能量费用。 相似文献
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运用Aspen Plus软件回归文献数据校正了碳酸二甲酯(DMC)-水(H2O)混合物的UNIQUAC热力学模型参数,并以该模型为基础分析了水作为萃取剂萃取精馏分离DMC-甲醇(CH3OH)-水三元混合物的分离原理,结合混合组分的三角相图和物料组成设计了反向萃取精馏工艺,发现选用水为萃取剂可以利用DMC-水的部分互溶特性,通过三塔精馏即可分离DMC-甲醇-水三元混合物,沸点较高的DMC和少量水由塔顶馏出,而沸点较低的甲醇和大部分水由塔底采出,避免了DMC-甲醇二元共沸物的形成。同时,在相同分离要求下设计了变压精馏工艺,通过对两个精馏工艺参数模拟优化,发现萃取精馏工艺的总冷凝负荷和总加热负荷分别为888.7kW和898.2kW,其总能耗较变压精馏工艺节约了47.2%,萃取精馏工艺的年总费用(TAC)比变压精馏工艺下降了48.8%。 相似文献
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二甲醚作为燃料的替代品,其生产开发在化学工程领域受到了广泛关注。本文对合成气一步法制备二甲醚过程进行了模拟分析,提出了用水作为吸收剂并采用多效精馏的二甲醚生产新工艺。利用Aspen Plus化工模拟软件对吸收塔进行模拟比较了甲醇和水作为吸收剂的能耗,模拟结果表明,用水吸收较甲醇吸收总热负荷降低23.54%,总冷负荷降低35.97%,更为节能。从节能降耗角度出发,根据不同的分离任务,提出了采用两塔分离甲醇-水及三塔分离甲醇-水的两项工艺改进措施。结果表明,采用两塔分离甲醇-水工艺比原工艺二甲醚产量增加了11.50%,能量消耗无明显变化。进一步采用三塔精馏工艺总冷负荷比原工艺减少45.07%,总热负荷减少19.27%,且二甲醚产量增加11.15%,节能效果显著。 相似文献
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《Gas Separation & Purification》1994,8(1):37-43
A ternary feed mixture ABC can be separated into individual components through the use of a main distillation column with a thermally linked side rectifier. To enhance such a separation, a heat pump can be implemented to transfer heat from the condenser at the top of the side rectifier to the reboiler at the bottom of the main column. In this paper, one such heat pump is described and applied to an air distillation system separating the ternary mixture containing nitrogen, oxygen and argon. The separation is performed by a conventional double column with a crude argon side column. When this system is operated at an elevated pressure to obtain higher product pressures, the separation of oxygen and argon becomes very difficult and leads to reduced argon recovery. The proposed heat pump enhances the separation by providing a supplementary crude argon condensing duty through the vaporization of a liquid oxygen stream from the bottom of the low pressure (LP) column. This scheme improves the liquid/vapour ratio (L/V) in the bottom section of the LP column and, more importantly, increases the vapour feed to the crude argon column. This increased feed rate leads to a substantial increase in argon recovery for the elevated pressure air distillation process. 相似文献