【作者】 张谦；

【导师】 朱家骅； 茅启昌；

【作者基本信息】 四川大学 ， 化学工程， 2003， 硕士

【摘要】 二甲醚(DME)具有一系列优良的物理化学性质，除广泛用于制药、染料、农药等工业和替代氟里昂用作汽溶胶喷射剂和制冷剂外，作为一种新型清洁能源，二甲醚市场前景非常乐观，是正在世界范围内迅速崛起的朝阳化工产品。 本文结合泸天化(集团)公司开发天然气化工深加工产品的战略部署，对10万吨／年二甲醚项目进行可行性研究。这么大规模的二甲醚装置国际上尚无先例，技术文献也大都严格保密。作者总结了前期参与设计的1万吨／年二甲醚工业试验装置的实践经验和运行情况，发现了引进日本东洋工程公司(TEC)二步法甲醇脱水工艺生产二甲醚技术在合成圈热量平衡上存在的问题。通过深入分析与计算，认为： 1．TEC技术其合成圈系统不能达到热量平衡，其主要原因是甲醇预热器换热量不足，产品气离开系统的温度(142℃)过高。 2．由此造成的欠热工况会使装置在正常生产工况下合成圈内的开车加热器也不能退出。这种情况放大到10万吨／年规模很可能会影响到合成圈的正常运行。分析发现，欠热工况还会向精馏工序转移，带来更多的不利影响。 3．合成系统的热量平衡与全系统的热能利用好坏会影响到装置的重要技术经济指标，必须进行工艺流程和设备的优化设计，这是占领低价四川大学工程硕卜专业学位论文 位、大容量二甲醚产品能源市场的技术要害。 在此基础上，作者提出了二步法甲醇脱水工艺10万吨/年二甲醚生产装置的优化流程，并采用ECSS软件对全系统进行了物料平衡。还完成了关键设备进出气换热器，DME精馏塔和甲醇蒸馏塔的详细工艺设计。本设计的特点是装置内热能利用充分，流程简洁明畅，工艺条件温和，操作简易方便。而且设备台数较少，设备制作立足于国内现状，均能在国内制造而不需进口，可大大降低项目投资。 按国家现行基本建设政策和市场价格对本项目进行了财务评价计算。工程总投资估算值13880万元，项目的内部收益率所得税前为13.82%，高于基准收益率12%。其它各项效益指标及盈亏平衡分析结果均表明本项目具有很强的抗风险能力。 上述各方面问题的研究结果表明，10万吨/年二甲醚项目符合国家产业政策和未来能源市场发展方向，市场预测乐观，工艺方案合理，工艺技术成熟可靠，投资估算和财务评价结果也表明项目经济效益明显。本研究证明沪天化10万吨/年二甲醚项目可行。更多还原

【Abstract】 Dimethylether (DME) is widely used as raw materials with many excellent physical and chemical properties for manufacturing of pharmacy, dye, pesticide etc. It is also a ideal substitute for trichlorofluoromethane as refrigerant or spraying solvent. Recently DME as a new clean fuel, its production capacity has been expanding rapidly with a very promising world market evaluation.This paper makes a fundamental feasibility investigation and engineering study to the suggested project of 100kt/a DME for LuTianhua Group Co., combining with the implemented strategy of downstream products development for the chemical productions based on natural gas processing in the compony. This will be the first DME project with such a large scale in the world. There is no example to follow and most all the "know how" skills keep secret strictly. The author carries out a sound analysis to the problems existing in the 10kt/a DME pilot experimental systems, in which the author accumulated valuable experiences through the design and trial running. The serious disfigurement of energy balance is found in the synthesis loop of the Two-step Methanol Dehydration Process which was imported from TEC Co. of Japan. Through careful analysis and calculation, the following conclusions are obtained:1. The main reason for the energy balance problem existing in TEC technique is the deficiency of heat exchange capability of the heater for methanol pre-heating in the synthesis loop. As a result the temperature of product gas is too high (142 ) at the output end.2. Consequently, the deficiency of process energy lets to a problem. The auxiliary heat exchanger in the synthesis loop designed for system starting operation could not exit under the normal production conditions. This problem would affect the operation very seriously if it is scaled up to the large scale of 100kt/a. Furthermore, the condition of energy deficiency will spread to the distillation loop and cause much more adverse affects to the system,3. The energy balance for the synthetic loop and rational utilization of heat energy in the whole system are very important in affecting the technological and economical performances of DME process process. A optimal analysis must be done to the process layout and equipment design. This would be the key factor for the product to take over the huge market of DME with a competitive advantage of lower price.Based on the the above analyses, the author proposed an optimal design for the 100kt/a DME plant with Two-step Methanol Dehydration Process, using the software ECSS, a detailed material balance is made to the whole system. The process design is completed for the key equipment of heat exchanger for the process streams of inlet and outlet, DME rectifying tower and methanol distillation tower. The characteristic advantages of this design are summarized as follows: full utilization of heat energy within the system, compact and clear flow sheet, moderate process condition and flexibility and facility for operation. And the number of equipment is less than the original technique of TEC Co.. The design makes it possible for all the equipment to be manufactured domestically so the project investment can be greatly reduced.According to the current infrastructure policy and the market price, it is estimated that the total project investment is 138.8 million RMY. The inner yield before income tax is 13.82%, which is higher the basic requirement of yield 12%.The analysis of profit and loss and other benefit index indicate that the risk sustaining ability of this project is very strong.It is proven by this work that the project of 100kt/a DME for LuTianhua Group Co. is in accordance with the country’ s current industrial policy and the direction of development of energy market. There is an optimistic prediction of market. The process design is rational and the technique is reliable. The estimation of investment and evaluation of finance indicate the economic profit. All the evidence obtained by this investigation show a positiv更多还原