Catalyst – solid sorbent – or support therefor: product or process – Catalyst or precursor therefor – Metal – metal oxide or metal hydroxide
Reexamination Certificate
2000-04-28
2002-04-09
Bell, Mark L. (Department: 1755)
Catalyst, solid sorbent, or support therefor: product or process
Catalyst or precursor therefor
Metal, metal oxide or metal hydroxide
C502S314000, C502S315000, C502S316000, C502S319000, C502S321000, C502S323000, C502S324000, C148S403000, C148S561000
Reexamination Certificate
active
06368996
ABSTRACT:
FIELD OF THE INVENTION
The present invention relates to a hydrogenation catalyst and its preparation.
BACKGROUND OF THE INVENTION
The hydrogenation has been extensively applied in processes such as the hydrogenation of olefin, alkyne, aromatics, nitro compounds, carbonyl groups, nitrile groups and other unsaturated compounds, and hydrorefining of crude products such as caprolactam in chemical, especially fine chemical, engineering field. The most widely used catalyst in these processes is skeletal nickel (Raney nickel) catalyst which has been applied in the industry for many years and has become technically matured, and so long no other catalyst can substitute for it. In recent years, a widely reported amorphous alloy catalyst has shown its superiority to Raney nickel catalyst in respect of activity and selectivity with the momentum of taking the place of Raney nickel catalyst.
Amorphous alloys are a new kind of catalyst materials in which the atoms are in short-range ordered but long-range disordered arrangements, thus ensuring that the catalysts have an increased number of active sites in a uniform distribution. However, ordinary amorphous alloys have the disadvantage of low activity and small specific surface area, which cannot exceed 10 m
2
/g even after various chemical and physical treatments, thus its prospect of industrial application is limited. In this connection, CN1073726A discloses a process for the preparation of a large-surface-area Ni(Fe or Co)—Re—P amorphous alloy catalyst by alloying nickel or Fe or Co—Re—P and aluminum using the rapid quenching and moulding method and then leaching out the aluminum with alkali to obtain an amorphous alloy catalyst having a specific surface area of up to 50-130 m
2
/g which make it possible to be used in industry. In comparison with Raney nickel catalyst, the Re—Ni—P catalyst has a distinctly higher activity in the saturation-hydrogenation of olefin and aromatic hydrocarbons (see CN1146443A).
CN1152475A discloses a ferric magnetic amorphous alloy catalyst consisting essentially of 45 to 91 wt % nickel, 2 to 40 wt % iron based on the weight of the catalyst and P in balance. The catalyst obtained in this manner has higher catalytic activity than the catalyst described in the CN1073726A.
U.S. Pat. No. 3,839,011 discloses a Raney nickel catalyst and its preparation. The catalyst is prepared by melting nickel and aluminum, pouring the molten alloy into a flowing water stream to be cooled. A readily crushable catalyst of low bulk density is obtained by this process. However, this process cannot provide an amorphous alloy catalyst having an amorphous structure of adequate stability.
U.S. Pat. No. 5,090,997 discloses a process for preparing a Raney nickel catalyst. The catalyst is obtained by heating the molten aluminum alloy to a temperature of 50 to 500° C. above its melting point, atomizing the liquid melt with water or a mixture of water and gas, then cooling the atomized alloy in water or air to obtain a fine particle Raney nickel catalyst. It is difficult to obtain an amorphous catalyst having a higher degree of amorphism by this method owing to its lower cooling rate.
The caprolactam is a main material for producing nylon-6. The purification of caprolactam is a key process for producing caprolactam. The process for producing area Ni(Fe or Co)—Re—P amorphous alloy catalyst by alloying nickel or Fe or Co—Re—P and aluminum using the rapid quenching and moulding method and then leaching out the aluminum with alkali to obtain an amorphous alloy catalyst having a specific surface area of up to 50-130 m
2
/g which make it possible to be used in industry. In comparison with Raney nickel catalyst, the Re—Ni—P catalyst has a distinctly higher activity in the saturation-hydrogenation of olefin and aromatic hydrocarbons (see CN1146443A).
CN1152475A discloses a ferric magnetic amorphous alloy catalyst consisting essentially of 45 to 91 wt % nickel, 2 to 40 wt % iron based on the weight of the catalyst and P in balance. The catalyst obtained in this manner has higher catalytic activity than the catalyst described in the CN1073726A.
U.S. Pat. No. 3,839,001 discloses a Raney nickel catalyst and its preparation. The catalyst is prepared by melting nickel and aluminum, pouring the molten alloy into a flowing water stream to be cooled. A readily crushable catalyst of low bulk density is obtained by this process. However, this process cannot provide an amorphous alloy catalyst having a amorphous structure of adequate stability.
U.S. Pat. No. 5,090,997 discloses a process for preparing a Raney nickel catalyst. The catalyst is obtained by heating the molten aluminum alloy to a temperature of 50 to 500° C. above its melting point, atomizing the liquid melt with water or a mixture of water and gas, then cooling the atomized alloy in water or air to obtain a fine particle Raney nickel catalyst. It is difficult to obtain an amorphous catalyst having a higher degree of amorphism by this method owing to its lower cooling rate.
The caprolactam is a main material for producing nylon-6. The purification of caprolactam is a key process for producing caprolactam. The process for producing caprolactam comprises the following steps: benzene hydrogenation to cyclohexane, cyclohexane oxidization to cyclohexanone, cyclohexanone oximation to cyclohexanone oxime and Backmann rearrangement of cyclohexanoneoxime in oleum. The products obtained therefrom include caprolactam and unsaturated compounds. These by-products cannot be removed by extraction and distillation because of their analogical properties. However, the presence of these unsaturated compounds are disadvantageous because they can impair the physical-mechanical properties of the nylon-6 made by polymerizing &egr;-caprolactam, so they must be removed. During the purification of caprolactam, the unsaturated impurities are saturated by hydrogenation, while their physical-mechanical properties become distinguishable from that of caprolactam, so that these compounds are more easily removed in the subsequent extraction distillation steps. In conventional technology, Raney nickel catalyst is used, but Raney nickel catalyst, with its relatively low activity, larger amount of consumption and limited ability in removing all disturbing impurities, cannot meet the demand of the technological development.
DESCRIPTION OF THE INVENTION
The object of the present invention is to provide a new kind of amorphous alloy hydrogenation catalyst with high activity and high purification capability which has a higher degree of amorphism and higher stability in amorphous state and is particularly useful to hydrorefining of caprolactam, and its preparation.
The hydrogenation catalyst according to the invention comprises essentially Ni ranging between 60 and 98 wt %, Fe ranging between 0 and 20 wt %, one doping metal element selected from the group consisting of chromium, cobalt, molybdenum, manganese and tungsten ranging between 0 and 20 wt %, and aluminum ranging between 0.5 and 30 wt % based on the weight of said catalyst, wherein the weight percentages of iron and the doping element components should not be zero at the same time; and just one broad diffusion peak appears at about 2 &thgr;=45±1° on the XRD patterns of the catalyst within 2 &thgr; range from 20 to 80°.
The catalyst according to the present invention comprises preferably nickel ranging from 70 to 95 wt %, iron ranging from 0.1 to 15 wt %, a metal selected from the group consisting of chromium, cobalt, molybdenum, manganese and tungsten ranging from 0 to 15 wt %, and aluminum ranging from 1 to 15 wt % based on the total weight of said catalyst.
In said catalyst according to the present invention, the nickel content of amorphous alloy is more preferably in the range from 75 to 90 wt %, iron content is more preferably in range from 0.3 to 10 wt %, a metal selected from the group consisting of chromium, cobalt, molybdenum, manganese and tungsten content is more preferably in the range from 0.5 to 8 wt %, and aluminum content is more preferably in the range
Min Enze
Mu Xuhong
Shu Xingtian
Wang Xuan
Wang Ying
Bell Mark L.
China Petroleum Corporation
Hailey Patricia L.
LandOfFree
Hydrogenation catalyst and its preparation does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Hydrogenation catalyst and its preparation, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Hydrogenation catalyst and its preparation will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2906638