【作者】 刘健；

【导师】 张述伟；

【作者基本信息】 大连理工大学 ， 化学工艺， 2008， 硕士

【摘要】 以煤炭资源替代部分油、气资源,是我国经济建设可持续发展的必由之路。我国的石油、天然气储量相对不足,煤储量丰富,因此发展煤制油、天然气和化工产品的研究具有重大的意义。甲醇消费量仅次于乙烯、丙烯和苯排第四位。甲醇不仅是重要的化工原料,也是洁净燃料。发展大型煤制甲醇,是国家能源安全的需要,也是化学工业高速发展的需要。甲醇合成的原料气为CO和H₂,可由煤、天然气、轻油、裂解气及焦炉气来制取。近年来,随着天然气和石油资源的日趋紧张,在富产煤的地方利用以煤为原料制取甲醇备受重视。在以鲁奇炉制煤气为原料生产甲醇的工艺流程中,煤气的净化工段是十分重要的环节。煤气中的硫化物在甲醇生产中会产生非常有害的影响,会造成催化剂中毒,故需除净。采用鲁奇炉加压气化技术生产的甲醇合成气中含有一定量的轻烃物质、二氧化碳、硫化物、氨气以及苯等有害杂质,必须将其除去。低温甲醇洗法是利用低温下（-50℃～-70℃）甲醇的优良特性脱除原料气中的轻质油、二氧化碳、硫化氢、硫氧化碳和氰化物等的物理吸收法,能将合成气中的硫化物脱至0.1ppm。低温甲醇洗法的特点:吸收能力大,气体净化度高,出口气中二氧化碳可脱除至10-20ppm;作为吸收剂的甲醇易得,价格低廉;选择性好,甲醇对CO₂、H₂S、COS的溶解度大,但对H₂、CO、CH₄的溶解度小;沸点低,它的热再生温度低,能耗低。甲醇洗净化后的甲醇合成气中还含有CH₄等惰性气体,必须控制在一定的量以下,以鲁奇炉生产的合成气中的甲烷含量较高,通过深冷分离的方法将惰性气体甲烷回收,省去了传统的甲烷转化装置,得到了较纯净的甲烷副产品,可作为国内LPG燃料和天然气的替代和补充。由于鲁奇炉固定床加压气化的技术生成气中甲烷含量大以及当前国内天然气市场前景广阔的原因,将低温甲醇洗净化后的合成甲醇的原料气采用深冷回收惰性气体甲烷的流程具有很强的实际意义。低温甲醇洗与深冷分离均属于冷法操作,在低温下配合使用,节能效果良好。采用低温甲醇洗工艺和深冷分离相结合的工艺流程,有效地脱除了硫化氢和二氧化碳等气体,回收了合成甲醇工段的惰性气体甲烷。本文用通用流程模拟软件对全流程进行了模拟和优化分析,设计出了更加节能的工艺流程。更多还原

【Abstract】 Using coal resource to substitute partial oil and gas resource is the only way for economic sustainable development of our country. The reserves of oil and natural gas is not abundant relatively, but the coal reserves is abundant, so it’s important to develop the study of using coal to make oil, natural gas and chemical product. The consumption of methanol is inferior to the ethylene, the propylene and the benzene and ranks four. Methanol is not only important chemical raw material, but also it is pure fuel. To develop the study of using coal to make methanol is not only the need of our country’s energy safety, but also it is the need of high speed of development of chemical industry. The crude gas of methane-synthesis is carbon monoxide and hydrogen, and they can be made by coal, natural gas, light hydrocarbon, pyrolysis gas and coke oven gas. Recently, with the lack of natural gas and petroleum resource day after day, taking use of coal to produce methanol is recognized in the place which has plenty of coal resource. During the technology process of producing methanol using the Lurgi furnace coal gas as raw material, the workshop section of coal gas purification is very important tache. The sulfide of coal gas can make a very bad effect during the process of methanol production, and it can make the catalyst poison, so it must be cleaned utterly.The methanol synthesis gas adopting the Lurgi furnace pressurized coal gasification technology contains certain amount of light hydrocarbon material, carbon dioxide, sulfur oxides, ammonia, benzene and other harmful impurities, and they must be cleared. The Rectisol process is a physical absorption method of using the excellent character of low temperature methanol to remove the light hydrocarbon, carbon dioxide, sulfureted hydrogen, carbon oxysulfide, cyanide and so on, and it can remove the sulfides from the synthesis gas by 0.1ppm. The characters of the Rectisol process are as follows: good absorbency, high gas purification degree, carbon dioxide can be removed from export gas by 10-20ppm, and the inorganic and carbon oxysulfide can be cleaned by less than 0.1 ppm; as a absorbent, the methanol can be acquired easily, and it is very cheap; its selectivity is good, and the solubility of carbon dioxide, sulfureted hydrogen and carbon oxysulfide is very big, but the solubility of hydrogen, carbon monoxide and methane is very small; the temperature of boiling point is low, and its hot regeneration temperature is low, and the enemy of consumption is also low. The purified methanol synthesis gas after Rectisol process also contains the inert gases, such as methane and so on, so it must be controlled below certain amount. The methane content of synthesis gas made by Lurgi furnace is very high, the inert gas methane can be withdrawn by deep refrigeration separation, and this process can save the equipments of methane translation and acquires a purified methane side product which can be used as the substitute or supply of LPG fuel and natural gas.Because the content of methane in the technology generation gas using the Lurgi fixed bed furnace is very high and current domestic natural gas’s market foreground is very extensive, the process of adopting deep refrigeration to withdraw methane inlet gases from the raw material gas for methanol synthesis after the purification of Rectisol process has strongly actual meaning. Both the Rectisol process and deep refrigeration separation are operated at low temperature, so the effect of energy saving is pretty good when using them together. Adopting the process of the integration about Rectisol process and deep refrigeration separation, the sulfureted hydrogen and carbon dioxide gas was eliminated effectively and the inert gas methane of the phase of methanol-synthesis was withdrawn. This paper has designed a more economy process by the simulation and optimization analysis for the total flow using current simulation software.更多还原