Catalyst – solid sorbent – or support therefor: product or process – Catalyst or precursor therefor – Metal – metal oxide or metal hydroxide
Reexamination Certificate
2000-10-13
2003-02-11
Bell, Mark L. (Department: 1755)
Catalyst, solid sorbent, or support therefor: product or process
Catalyst or precursor therefor
Metal, metal oxide or metal hydroxide
C502S313000, C502S315000, C502S316000, C423S625000, C423S626000, C423S628000, C423S630000, C423S631000, C501S127000
Reexamination Certificate
active
06518219
ABSTRACT:
The invention relates to a catalyst for hydrorefining fraction oils and its preparation process as well as a carrier of the catalyst and its preparation process. More particularly, this invention relates to a catalyst for hydrorefining fraction oils, which comprises metal(s) and/or metal oxide(s) of Group VIB and metal(s) and/or metal oxide(s) of Group VIII, and its preparation process as well a carrier of the catalyst and its preparation process.
In recent years, the quality of crude oil resources is showing a tendency to deteriorate steadily worldwide; the content of sulfur, nitrogen and aromatics in the oils is also increasing obviously. The conflict between the ever-stringent environment regulations and this critical reality becomes intensified day by day. It is well known that hydrogenation process is one of the most efficient means for improving quality of the oils, in which hydrotreating catalyst is the most significant key technology. Therefore, many leading companies have already devoted themselves to improving the existing hydrotreating catalysts and continuously developing hydrotreating catalysts having better properties. The current trend in developing hydrotreating catalyst is focused on further reducing the metal content in the catalyst, increasing its catalytic activity and modifying the properties of carrier to render it more suitable for hydrotreating the inferior-quality oils.
Hydrotreating catalysts generally comprise metals and/or metal oxides having hydrogenation function as components and a catalyst carrier, some of the catalysts may contain additives also.
The mostly used metal and/or metal oxide possessing hydrogenation function is selected from metals and met al oxides of Group VIB and metals and/or metal oxides of Group VIII of the Periodic Table of Elements. Said metal and/or metal oxide of Group VIII can be one or more selected from the group consisting of the metals and/or metal oxides of iron, cobalt, nickel, ruthenium, rhodium, palladium, osmium, iridium and platinum, of which nickel and cobalt are mostly selected. Said metal and/or metal oxide of Group VIB can be one or more selected from the group consisting of the metals and/or metal oxides of chromium, molybdenum and tungsten, of which molybdenum and tungsten are mostly selected.
The mostly used additive is one or more selected from the group consisting of the oxides of magnesium, oxides of phosphorus and fluorine.
The mostly used catalyst carriers are those made of silica, alumina and silica-alumina, of which alumina is the most extensively applied catalyst carrier.
In U.S. Pat. No. 3,779,903, a carrier having pore volume of 0.15-0.45 ml/g is prepared via drying and calcining an alumina sol, from which a catalyst comprising 10-18 wt % nickel oxide, 25-40 wt % tungsten oxide and 1-9 wt % fluorine is obtained after the steps of impregnating the carrier with a solution of tungsten and nickel, drying and calcining. However, the catalyst has a high metal content, especially a very high the nickel content, hence resulting in a very high cost of the catalyst.
In U.S. Pat. No. 4,330,395 a catalyst for hydrorefining fraction oils is prepared by taking tungsten compound and aluminum compound as row materials, through drying, calcining and impregnating the carrier with a solution of nickel compound, and thereafter, sulfurizing and fluorinating the catalyst with sulfur compound and fluorine compound, respectively. This catalyst also has the same drawback of overhigh metal content, besides, the preparation process of the catalyst is relatively complex.
In CN 85,104,438B, a hydrorefining catalyst comprising 1-5 wt % nickel oxide, 12-35 wt % tungsten oxide and 1-9 wt % fluorine is manufactured by taking high-purity boehmite as precursor of the catalyst carrier, which is prepared through hydrolysis reaction of alkoxyl aluminium or alkyl aluminium. Although the catalyst has lower metal content and is one of the most active hydrorefining catalysts for fraction oils in the prior art, the cost of the catalyst is still relatively high because the precursor of the catalyst carrier is made of the expensive boehmite.
CN 1,169,336A discloses a catalyst for hydrorefining fraction oils and its preparation process. The catalyst consists of 1-5 wt % nickel oxide, 12-35 wt % tungsten oxide, 1-9 wt % fluorine and alumina as the remainder. Said alumina was prepared by compounding one or more microporous alumina(s) with one or more macroporous alumina(s) in the weight ratio of 75:25-50:50. In said microporous alumina, the volume of pores having a diameter of less than 80 angstrom accounts for more than 95% of the total pore volume; in said macroporous alumina, the volume of pores having a diameter of 60-600 angstrom accounts for more than 70% of the total pore volume. The preparation process of the catalyst comprises, forming and calcining the alumina precursor; then impregnating the material obtained in the previous steps sequentially with a fluorine-containing aqueous solution and a nickel-tungsten containing precursors aqueous solution; drying and calcining after each impregnation step. Said alumina precursor is a mixture of the precursors of said microporous alumina and said macroporous alumina. In this mixture, the ratio of said microporous alumina precursor to said macroporous alumina precursor is so set that the weight ratio of said microporous alumina to said macroporous alumina in the final catalyst product falls in the range of 75:25-50:50. In the alumina carrier of the catalyst as prepared by this process, the volume of pores having a diameter ranging from 40-100 angstrom accounts for higher than 75% of the total pore volume and the catalyst is one of the most active hydrotreating catalysts for fraction oils in the prior art, but the preparation process of the catalyst is rather complex due to the use of two kinds of alumina.
In addition, CN 1,105,053A discloses a catalyst suitable for hydrorefining heavy fraction oils. Said catalyst comprises 1-5 wt % nickel oxide, 15-38 wt % tungsten oxide and 1-9 wt % fluorine as well as a carrier of modified alumina that is obtained by high-temperature treatment in the present of air and steam. The pore distribution of the modified alumina is concentrated in the range of 60-200 angstrom. However, obviously the process has shortcomings in its complicated preparation technology and high energy-consumption as a result of the adoption of high-temperature treatment with air and steam.
As a carrier of hydrogenation catalyst, the differences in pore structure, acidity and preparation method of the alumina manifest a great influence on the catalytic performance. Therefore, many preparation methods have been developed in the prior art in order to meet the requirements of different catalysts for the properties of the carriers.
Take &ggr;-Al
2
O
3
for example, pseudo-boehmite via calcination forms &ggr;-Al
2
O
3
which is a mostly used carrier or substrate of catalysts. The properties of &ggr;-Al
2
O
3
play a very important role in the comprehensive performance of the catalyst when it is used as the carrier or substrate of the catalyst. In general, it is desired that the pseudo-boehmite should have a relatively high crystallinity. The content of bayerite as impurity shall be at very low level, preferable nonexistent. In addition, the content of ion impurities shall be at low level also, the acid radical ions in the alumina product, such as the sulfuric acid radical ions shall not be higher than 2 wt % and alkali metal oxides not higher than 0.15 wt %. The &ggr;-Al
2
O
3
carrier formed by calcination of pseudo-boehmite shall possess relatively larger specific surface area, higher strength and proper pore volume as well as narrow pore distribution.
In the prior art, a conventional process for preparing pseudo-boehmite and &ggr;-Al
2
O
3
is known as sodium meta-aluminate (or sodium aluminate)-aluminium sulfate (aluminium nitrate, aluminium muriate, nitric acid, or sulfuric acid) process.
U.S. Pat. No. 2,980,632 discloses a process for preparing an alumina-based catalyst, comprising pr
Li Dadong
Liu Bin
Liu Xuefen
Nie Hong
Shi Yahua
Bell Mark L.
China Petro-chemical Corporation
Hailey Patricia L.
Morrison & Foerster / LLP
LandOfFree
Catalyst for hydrorefining fraction oils, its carrier and... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Catalyst for hydrorefining fraction oils, its carrier and..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Catalyst for hydrorefining fraction oils, its carrier and... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3157162