摘要
为了探究金属浸渍液中各物种在氧化铝载体表面的竞争吸附,通过在溶液中引入不同类型的添加剂进行了相应的平衡吸附试验。结果发现在七钼酸铵溶液中引入偏钨酸铵会在一定程度上降低钼平衡吸附量,二者在氧化铝中性羟基上的竞争吸附有利于减弱钨物种与氧化铝的强相互作用。在七钼酸铵溶液中分别引入硝酸铵、氯化铵、硫酸铵、丙三醇和聚乙二醇对钼平衡吸附量影响不大,但引入磷酸或其铵盐则可明显降低钼平衡吸附量,表明其可与钼物种产生较强的竞争吸附,从而减弱钼物种与氧化铝的相互作用,促进钼物种的硫化。引入柠檬酸铵也可明显降低钼平衡吸附量。另外,氧化铝载体在以[PMo_(12)O_(4)0]^(3-)结构为主的磷钼酸溶液中的钼平衡吸附量明显高于在以[P_(2)Mo_(5)O_(23)]^(6-)结构为主的磷钼酸溶液中的钼平衡吸附量。而且,通过调控含有柠檬酸的镍钼浸渍液中P/Mo物质的量之比,可以改变钼前驱体的分子结构以及游离的磷酸根和柠檬酸根离子的数量;并且氧化铝的钼平衡吸附量随着溶液中P/Mo物质的量之比的提高而逐渐降低。研究结果为统筹设计金属浸渍液的组成以及开发高效加氢催化剂提供了必要的理论和技术支持。
To study the competitive adsorption of various species on the surface of alumina carrier in metal impregnation solution,the corresponding equilibrium adsorption experiments were conducted by introducing different types of additives into the solution.The results showed that the addition of ammonium metatungstate into ammonium heptamolybdate solution could reduce molybdenum equilibrium adsorption capacity to a certain extent,and the competitive adsorption on the neutral hydroxyl groups of alumina was beneficial for weakening the strong interaction between tungsten species and alumina.Adding ammonium nitrate,ammonium chloride,ammonium sulfate,glycerol and polyethylene glycol into ammonium heptamolybdate solution had little effect on molybdenum equilibrium adsorption capacity,but adding phosphoric acid or its ammonium salt could significantly reduce molybdenum equilibrium adsorption capacity.The results showed that the molybdenum species could be adsorbed competitively,the interaction between molybdenum species and alumina was weakened,and the sulfidation of molybdenum species was promoted.The introduction of ammonium citrate could also significantly reduce molybdenum equilibrium adsorption capacity.In addition,molybdenum equilibrium adsorption capacity of the alumina carrier in the phosphomolybdic acid solution dominated by the[PMo_(12)O_(40)]^(3-)structure was significantly higher than that in the phosphomolybdic acid solution dominated by the[P_(2)Mo_(5)O_(23)]^(6-)structure.Furthermore,the molecular structure of molybdenum precursors and the amount of free phosphate and citrate ions could be changed by adjusting the P/Mo mole ratio in metal impregnation solutions containing citric acid.The molybdenum equilibrium adsorption capacity of the alumina carrier gradually decreased with the increase of the P/Mo mole ratio in the solution.The results provide the necessary theoretical and technical support for designing the composition of metal impregnation solution and developing high-efficiency hydrotreating catalyst.
作者
李会峰
李明丰
刘锋
聂红
Li Huifeng;Li Mingfeng;Liu Feng;Nie Hong(National Energy R&D Center of Petroleum Refining Technology,SINOPEC Research Institute of Petroleum Processing Co.,Ltd.,Beijing 100083)
出处
《石油炼制与化工》
CAS
CSCD
北大核心
2024年第10期1-8,共8页
Petroleum Processing and Petrochemicals
基金
国家重点研发计划项目(2017YFB0306500)
中石化石油化工科学研究院有限公司课题(R16091)。
关键词
氧化铝
钼平衡吸附量
金属前驱体
磷
柠檬酸
竞争吸附
alumina
molybdenum equilibrium adsorption capacity
metal precursor
phosphorous
citric acid
competitive adsorption
