多晶硅生产中还原尾气回收过程的节能降耗Aspen Plus模拟研究

发布时间：2018-03-10 00:00

本文选题：多晶硅　切入点：还原尾气分离　出处：《湖南大学》2014年硕士论文　论文类型：学位论文

【摘要】：近年，太阳能利用技术的不断发展，使得生产太阳能电池的原材料—多晶硅引起了人们的广泛关注。多晶硅的生产方法主要有改良西门子法、硅烷法、冶金法等，以改良西门子法生产多晶硅的应用最为广泛。但是从目前的生产状况来看，改良西门子法生产多晶硅的核心技术依旧掌握在仍然被发达国家垄断，因此国内多晶硅的生产技术落后、能耗高、生产成本相对较高等问题，特别是尾气干法回收工艺。该工艺作为多晶硅生产的核心工艺部分，对整个工艺的能量消耗、物料的循环利用有着重要的影响。因此，降低多晶硅生产中还原尾气分离回收利用过程的能耗是非常有意义的。本文以国内某公司年产3200吨多晶硅的生产装置为基础，以多晶硅生产还原尾气为研究对象，以氯硅烷为吸收剂，以氯化氢和氢气为目的产物，利用AspenPlus软件，选用NRTL物性方法和严格计算模块RadFrac，对尾气吸收解吸分离工艺流程进行模拟。吸收解吸分离工艺主要设备包括吸收塔、解吸塔和换热器，流程简单，，操作方便，结果可靠。模拟结果显示：氯化氢的吸收率达到99.00%，与原始吸收解吸工艺流程取得了相同的吸收解吸分离效果。其次，运用灵敏度分析法，对原吸收解吸分离工艺进行操作参数的优化，主要从以下几点进行模拟：吸收塔和解吸塔的各进料物流的温度、各设备的操作压力、吸收剂的流量以及吸收解吸两塔的理论塔板数等方面，以便确定各个操作参数对氯化氢吸收解吸效果和系统能耗的影响。最后，介绍了精馏塔设置中间换热器的工艺和分股进料工艺的节能原理以及其相关工艺参数的确定原则，提出改进的两种工艺流程，分别是解吸塔塔顶置中间冷凝器的工艺流程和富液分流分股进料的工艺流程，并且对两流程进行模拟分析，结果显示：与原始工艺的负荷相比，中间冷凝器工艺和分股进料工艺都有节能的迹象，相对来说，中间换热器工艺节能不是特别明显，但是采用分股进料工艺，吸收-解吸体系节能非常明显，可以使得低温冷量节约26.85%，蒸汽用量节约28.95%。可见，在多晶硅生产中还原尾气回收中采用分股进料工艺可以达到节能的效果。
[Abstract]:In recent years, the development of solar energy technology, the raw materials, polysilicon production of solar cells has attracted widespread attention. The main method of producing polysilicon have improved SIEMENS method, silane method, metallurgical method, the modified SIEMENS polysilicon production is most widely used. But from the present situation of the core. Technology for production of polysilicon in the improved SIEMENS method remain still monopolized by developed countries, so the domestic polysilicon production technology backward, high energy consumption, the production cost is relatively high, especially dry tail gas recovery process. The technology as the core technology of polysilicon production of the whole process, the energy consumption of the circulation of the material utilization an important influence. Therefore, reduction in the production of polysilicon reduction exhaust gas separation recycling process of the energy consumption is very meaningful.
The production device taking a domestic company with an annual output of 3200 tons of polysilicon based on polysilicon production reduction exhaust gas as the research object, using chlorosilane as absorbent to hydrogen chloride and hydrogen production by using AspenPlus software, the NRTL property method and strict RadFrac calculation module, the tail gas absorption desorption separation process was simulated. The absorption desorption separation process of main equipment including absorption tower and desorption tower and heat exchanger, simple process, convenient operation, reliable results. The simulation results show that the hydrogen chloride absorption rate reached 99%, and the original absorption desorption process has achieved the same effect of absorption and desorption separation.
Secondly, using the sensitivity analysis method, to optimize the operation parameters of the original absorption desorption separation process is simulated, mainly from the following points: absorption tower and desorption tower the feed stream temperature, the equipment operating pressure, the number of theoretical plates such as absorbent flow rate and absorption desorption tower two, in order to determine effects of various operating parameters on hydrogen chloride absorption desorption effect and energy consumption of the system.
Finally, the principle to determine the energy saving principle is introduced and the split column set of intermediate heat exchanger feeding process and related parameters, puts forward two kinds of process improvement, are the technology process and the rich liquid desorption tower top middle condenser shunt split feed, and simulation analysis of the two process, the results showed that: compared with the original process load, intermediate condenser technology and split feed process have such signs, relatively speaking, the middle of the heat exchanger energy-saving process is not obvious, but the split feed process, absorption desorption system of energy is very obvious, can make the cryogenic energy savings of 26.85%, steam saving 28.95%. visible in polysilicon production in reducing tail gas recovery by the split feed process can achieve the effect of energy saving.

【学位授予单位】：湖南大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TQ127.2;TM914.4

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