3. 工艺流程确定

本设计为年产量为3万吨五氟氯乙烷加氢脱氯制备五氟乙烷工艺，经最后计算结果分析，本流程考虑采用多个反应器同时进行反应，所以相关流程可以分为3个部分的工艺操作。为方便叙述，本工艺分各各工段进行具体说明。

反应工段：五氟氯乙烷和氢气分别通过泵进入换热器，将氢气经过压缩和增湿后在经过经期加热器预热至一定的温度，将氢气、五氟氯乙烷通入已经加入催化剂Pd／C的固定床列管反应器中充分接触混合反应。

吸收工段：从混合器中出来的高温气体先经过废热锅炉回收热量，气体冷却再进冷却塔冷却到-4.7℃～19.5℃，使其中的HF、CF3CH3被液化即可分离，剩余得混合气体再通入水循环塔，用清水吸收HCl，再将剩余得混合气体送入精馏塔精制。

精制工段：精制部分是将产物和未反应得原料进行分离，获得较高纯度的五氟乙烷。使用精馏塔是复合精馏塔，由于五氟乙烷和五氟氯乙烷的沸点相差很少，所以以甲醇为萃取剂采用萃取精馏法分离五氟乙烷和五氟氯乙烷，再将五氟氯乙烷循环加入反应器。

4. 工艺参数

(1) 生产能力：30000t五氟乙烷

  每年的生产时间：320天

  即3906.3kg/h五氟乙烷

(2) 产品规格：

五氟氯乙烷转化率为74.5%，五氟乙烷选择性为74.4%

(3) 其他工艺参数：

原料五氟氯乙烷温度：25℃      

进料氢气温度：25℃

5. 设计原则

设计原则主要包括：产品的质量控制指标、安全、操作方便、投资省、便于安装等。

本设计查阅相关资料和参考了五氟氯乙烷生产厂家工艺参数后，确定了五氟乙烷合成的工艺路线和生产流程；继而针对年产3万吨五氟氯乙烷加氢脱率制备五氟乙烷工艺的设计任务进行相关的物料衡算和热量衡算，使用AUTOCAD绘制具有控制点图，车间设备布局和主要设备设计图的工艺流程图，并撰写和编写设计报告。

关键词： 五氟氯乙烷；五氟乙烷；加氢脱氯

Preparation of pentafluoroethane by hydrodechlorination of 30,000 tons/year of pentafluorochloroethane

Design project: Fluorine 30,000 tons/year of pentafluorochloroethane hydrodechlorination to prepare pentafluoroethane process design, pentafluoroethane (R125) as a colorless and odorless gas, and non-combustible gas. Because pentafluoroethane has the characteristics of extremely low toxicity and good metal compatibility, it plays an extremely important role in industrial production. At the same time, chlorofluorocarbons (CFCs), which are widely used as refrigerants, industrial cleaning agents and gas expansion agents, have many uses but have a strong destructive effect on the atmospheric ozone layer. At present, China has stopped the production and use of HCFCs. However, the treatment of existing CFCs is still a problem, and the development of alternatives to ODS has become one of the topics most concerned by researchers in the field of fluorochemicals.As an important species, pentachlorochloroethane (CFC-115) has become an ideal alternative. Therefore, the study of the hydrogenation of pentafluorochloroethane to prepare pentafluoroethane has certain practical significance.

1.Design source

HCFCs are harmful to the ozone layer. Now the process prepares existing CFCs through the process to produce pentafluoroethane that is harmless to the ozone layer. Pentafluoroethane can be used as a refrigerant, bactericide, and fire extinguishing agent in the chemical market. Full of possibilities,the country is now vigorously developing green chemistry.The transformation of fluorination plants to produce pentafluoroethane is a highly economical issue. To obtain high-purity pentafluoroethane, we need to solve the impurities generated during the reaction and need to upgrade the purification method because pentachlorofluoroethane is difficult. Removing from pentafluoroethane requires us to design more to obtain higher purity pentafluoroethane