Development Of Hydrofinishing Catalyst For Lube Base Oil Production

Aromatics content and colour of lube base oil are important quality specifications,which are related to oxidation stability of lube base oil.There are two lube base oil hydrofinishing methods to reduce the aromatics content and improve the colour of lube base oil:one is clay hydrofinishing process,a kind of physical prosess,but it has the drawback of higher labor strength.lower yield, higher energy consumption and worse quality,moreover,clay dust and spent clay residue may pollute the enviroment; the other is hydrofinishing process,compared to clay finishing process,the advantages of hydrofinishing process are as follows:①better quality;②higher yield;③lower energy consumption;④less environmental pollution problem;⑤less labor strength.But most ordinary hydrofinishing process can't improve the oxidation stability of the lube base oil, so it can't meet much stricter lube base oil specifications, it has the great significance for developing new hydrofinishing technology. The hydrofinishing catalyst is the core of the hydrofinishing technology, so it is urgent to develop a new hydrofinishing catalyst to effectively and economically improve the oxidation stability of lube base oil.The goal of this paper is to develop a hydrofinishing catalyst for lube base oil production, this paper introduced aromatic hydrocarbon ring opening reaction network. Fristly. amorphous silica-alumina carrier was prepared using co-precipitation method and preparation conditions, such as the content of Al2O3, pH value of the colloid, were examined in detail, and amorphous silica-alumina materials were characterized with the following characterization techniques:XRD, XRF, NH3-TPD and BET; the results of amorphous silica-alumina preparation conditions showed that the amount of acidity center wouldl increase,then decrease as the content of Al2O3 increased; as pH value of the colloid increased, surface area of amorphous silica-alumina would decrease,but pore volume and average pore diameter would gradually increase; the characterization results exhibited that the final amorphous silica-alumina had medium strength acidity and higher surface area and pore volume, thus the chain-broken ability was weak, and assured higher liquid yield. then using amorphous silica-alumina and Al2O3 as carrier, noble metal as hydrogenation components, the hydrofinishing catalyst with low metal content was prepared by highly dispersed co-impregnation method; then performance evaluation of hydrofinishing catalyst was carried out on a 20ml fixed-bed hydrogenation test unit, and operating conditions affecting catalyst performance were also investigated. Evaluation results exhibited that using hydroisomerization product of No.2 and No.4 vacuum fraction produced by No.1 Refining plant as feedstocks, the product qualities are as follows:aromatics content of less than 3%, colour of less than 0.5/1.0(No.2/No.4 vacuum fraction),oxidation stability (150℃) of more than 340min,total liquid yield of 100%; using isodewaxing product of No.2 and No.3 vacuum fraction produced by No.2 Refining plant as feedstocks, the product qualities are as follows: aromatics content of less than 3%, saybolt colour of more than 28#,liquid yield of 100%,which meet the APIⅡ/Ⅲlube base oil specification.