【作者】 金力强；

【导师】 韩方煜；

【作者基本信息】 青岛科技大学 ， 化学工程， 2006， 硕士

【摘要】 最近，我国自主开发了苯乙烯生产的配套技术，这些技术具有无污染，无腐蚀的优点，但存在能耗较高问题。研究如何通过改造苯乙烯装置用能方案以降低其能耗，具有重大的现实意义。 本文围绕这一主题，基于某工程实例，开展了苯乙烯装置的节能技术研究。 通过对新旧装置的单元能耗数据的进行对比，发现改造后新装置能耗升高的主要部位在乙苯精馏单元，表现为高压蒸汽消耗量上升，原因主要在于改造后烷基化单元苯循环量过大。经分析发现，高苯烯比的烷基化反应催化剂和烷基化产物先分离后进行烷基转移的工艺路线是导致苯循环量增加主要原因。 采用人工智能图表法合成了乙苯部分的最优换热网络，以此作为指导，提出了乙苯部分的节能方案。此方案只需改变乙苯部分的工艺管道，用蒸汽凝液代替循环水来移走多乙苯塔冷凝器的热量，不需增加换热器，改动量较小。计算结果表明，此节能方案可以达到节省冷却水81.7t／h和多回收1.6t／h低压蒸汽的效果。 对苯乙烯装置苯乙烯部分的换热网络进行了研究，结合苯乙烯部分的实际换热网络流程，提出了苯乙烯部分的节能方案。此方案以脱氢气为乙苯回收塔再沸器供热充分利用其高品位的能量，需要新增2个换热器。计算结果表明，采用此方案可以节省冷却水128.5t／h，节省中压蒸汽2.5t／h。 本文应用夹点技术对苯乙烯装置进行了用能诊断。结果显示，苯乙烯装置中，传统采用废热锅炉发生低压蒸汽的热回收方案值得商榷，这些高温位的能量完全可以用来加热装置中的高温冷物流，从而节省高品位公用工程的消耗量。 通过采用夹点技术对苯乙烯装置的用能方案进行调优处理，提出了全流程能量集成的节能改造方案。此方案以烷基化产物代替中压蒸汽为乙苯回收塔再沸器供热，以脱氢产物代替高压蒸汽为乙苯塔再沸器供热，需要移动3台换热器的位置。计算结果表明，在改造工程量较小的情况下，此方案可以节省高压蒸汽7.8t／h，节省中压蒸汽3.8t／h，效益可达720.7万元／年。更多还原

【Abstract】 The styrene production process has been developed by China independently. It is clean, without pollution and corrosion, but consumes substantial amount of energy. It is of great significance to study the energy-saving problem by optimizing the energy using scheme of styrene production process.Focusing on the subject and according to the real situation of a certain styrene plant, the energy saving technology of the styrene production process was studied in this paper.Based on the mathematical simulation, the energy consumption of each section was analyzed comparatively. The results show that the energy consumption arising was demonstrated by the high-pressure steam volume increasing. It was caused by the increased benzene recycling amount. Both the catalyst with high molar ratio of benzene to ethylene and process route composed of separating and then trans-alkylation’s reaction could cause high benzene recycling amount.The heat exchanger network of the ethyl-benzene section was studied, and the detailed reconstruction was put forward. Only the process pipe is changed, no more heat exchanger need to be added in this reconstruction. The calculation results showed that the ethylene-benzene section could save 81.7t/h cooling water and 1.6t/h low-pressure steam.The heat exchanger network of the styrene section was studied. A retrofit plan with only two more heat exchanger added was presented in this paper. The calculation results showed that the styrene section could save 128.5t/h cooling water and 2.5t/h middle-pressure steam.Energy diagnosis on styrene process was done by using pinch technology. Results showed that the energy recovery through generating low-pressure steam in waste heat boiler needs to be discussed. These heat streams could be used to heat the high temperature cold streams, so the high-quality heat utility could be saved.更多还原