超重力共沉淀法制备气相醛加氢催化剂研究

发布时间：2018-05-14 02:06

  本文选题：超重力共沉淀 + 醛加氢　； 参考：《东北石油大学》2011年硕士论文

【摘要】：丁醇和辛醇是重要的有机化工原料和化学助剂,主要用于制造增塑剂,广泛用于各种塑料和橡胶制品中,通过丁醛、辛烯醛加氢制得。 醛加氢反应是丁、辛醇生产过程中的关键过程之一,决定丁、辛醇产品的质量和收率。醛加氢反应根据使用的催化剂和进料状态不同被分为液相法和气相法。液相法采用镍系催化剂,反应器为填充床;气相法采用铜基催化剂,反应器为列管式固定床。气相法因反应压力低、工艺设备简单而被广泛使用,国内引进的丁辛醇装置大部分采用气相法。目前,使用的气相醛加氢催化剂主要是铜锌催化剂。 铜锌催化剂的活性与活性组分铜的分散度成线性关系,提高催化剂中活性组分铜的分散度有利于提高催化剂的加氢活性及加氢选择性。铜锌催化剂一般采用共沉淀法制备,在搅拌釜中完成共沉淀反应。传统搅拌釜由于结构上的限制,导致微观混合不均匀,而且共沉淀反应和老化反应在同一反应器内进行,晶体生长过程中的过饱和度不均匀,导致制备的催化剂中晶粒度不均一、晶粒度大,活性组分的分散度不高。 本文采用超重力共沉淀法制备气相醛加氢用铜锌催化剂,共沉淀反应在极大强化了相间传质过程的超重力环境下进行,实现微观混合均匀,共沉淀产物及时移出反应体系,老化反应在完全的宏观混合区完成,制备的催化剂晶粒度小、大小均匀,有效地提高了活性组分的分散度。 分析了超重力共沉淀法制备催化剂的影响因素,优化了催化剂制备工艺条件,并对制备的催化剂进行系统表征。在300ml加氢评价装置上进行了催化剂加氢评价试验,以大庆石化丁醛和辛烯醛为原料,在反应压力0.45MPa、热点温度180～200℃、体积空速0.4h~(-1)、氢醛体积比8000:1的工艺条件下,丁醛/辛烯醛转化率大于99.5%,丁醇/辛醇选择性大于99.0%,催化剂表现出良好的加氢活性和加氢选择性。
[Abstract]:Butanol and octanol are important organic chemical raw materials and chemical auxiliaries, mainly used in the manufacture of plasticizers, widely used in various plastics and rubber products, through hydrogenation of butyral and octenaldehyde. Aldehyde hydrogenation is one of the key processes in the production of butadiene and octanol, which determines the quality and yield of butadiene and octanol. The hydrogenation of aldehydes can be divided into liquid phase method and gas phase method according to the catalyst and feed state used. Nickel catalyst was used in liquid phase method with packed bed in reactor, and copper based catalyst was used in gas phase method, and the reactor was tubular fixed bed. Gas phase method is widely used because of its low reaction pressure and simple process equipment. At present, the gas phase aldehyde hydrogenation catalyst is mainly copper zinc catalyst. There is a linear relationship between the activity of Cu-Zn catalyst and the dispersion of active component copper. Increasing the dispersion of active component copper in the catalyst is beneficial to improve the hydrogenation activity and hydrogenation selectivity of the catalyst. Copper and zinc catalysts are prepared by coprecipitation method and coprecipitated reaction is completed in agitator. Because of the structural limitation of the traditional agitator, the microcosmic mixing is not uniform, and the coprecipitation reaction and the aging reaction are carried out in the same reactor, and the supersaturation in the crystal growth process is not uniform. As a result, the prepared catalyst is characterized by heterogeneous grain size, large grain size and low dispersion of active components. In this paper, copper and zinc catalysts for gas phase aldehyde hydrogenation were prepared by using high gravity coprecipitation method. The coprecipitation reaction was carried out in a hypergravity environment which greatly strengthened the mass transfer process between phases. The microcosmic mixing was achieved, and the coprecipitation products moved out of the reaction system in time. The aging reaction was completed in the complete macroscopical mixing region. The prepared catalyst was of small grain size and uniform size, which effectively increased the dispersity of the active components. The factors affecting the preparation of catalysts by hypergravity coprecipitation were analyzed, the preparation conditions of catalysts were optimized, and the prepared catalysts were systematically characterized. The catalyst hydrogenation evaluation test was carried out in the 300ml hydrogenation evaluation unit. Under the conditions of reaction pressure of 0.45 MPa, hot spot temperature of 180 ~ 200 鈩，

本文编号：1885827