Catalyst – solid sorbent – or support therefor: product or process – Miscellaneous
Reexamination Certificate
1999-09-29
2002-08-06
Griffin, Steven P. (Department: 1754)
Catalyst, solid sorbent, or support therefor: product or process
Miscellaneous
C502S305000, C502S315000, C502S325000, C423S625000, C423S626000, C423S628000, C423S629000
Reexamination Certificate
active
06429172
ABSTRACT:
This application is the national phase under 35 U.S.C. §371 of PCT International Application No.
PCT/JP99/00391 which has an International filing date of Jan. 29, 1999, which designated the United States of America.
The present invention relates to a method for manufacturing a pseudo-boehmite powder as a raw material for producing a carrier for a catalyst for hydrogenation refining. In particular, the present invention relates to a method for manufacturing pseudo-boehmite by effectively utilizing waste water and sludge discharged from the aluminum surface-processing steps, and the present invention also relates to a method for producing a catalyst carrier and a method for producing a hydrogenation catalyst.
BACKGROUND ART
In the petroleum refining, a catalyst, in which a metal component having a hydrogenation ability is carried on an alumina carrier, is used as catalyst for hydrogenation refining in many cases. The alumina carrier can be produced by mixing, kneading, and forming a fine powder of pseudo-boehmite as an alumina hydrate, followed by calcination. The pseudo-boehmite powder, which is used as a raw material for the alumina carrier as described above, is produced by using a first method (1) in which an aluminic acid or aluminum salt is formed from gibbsite (aluminum hydroxide) followed by performing a reaction therewith, or a second method (2) in which aluminum alkoxide is hydrolyzed to synthesize the pseudo-boehmite powder. The characteristics of the obtained catalyst are greatly affected by the quality and the characteristics of the alumina carrier and the pseudo-boehmite. Therefore, in general, a high purity aluminum source is used as the raw material of the pseudo-boehmite powder.
When an aluminum product to be used for building materials such as sashes made of aluminum is produced, a treatment is performed in which an aluminum oxide coating forms on the formed aluminum by means of an electrochemical method to improve the corrosion resistance, the abrasion resistance, and the appearance of beauty. This treatment uses a process comprising the steps of, for example, anodization, etching, and washing with water, and it is called the alumite treatment.
FIG. 1
shows a series of aluminum surface treatment process including the alumite treatment.
As shown in
FIG. 1
, the aluminum material is first subjected to the surface degreasing, and it is washed with water. After that, the material is subjected to the alkaline etching step. In the alkaline etching step, the surface of aluminum is dissolved with caustic soda or sodium hydroxide in an amount of several &mgr;m to several tens &mgr;m. Subsequently, the steps of washing with water, neutralization, and washing with water are performed, and then the material is subjected to anodization or an anodic oxidation step. In the anodization, an oxide coating is formed on the surface of the aluminum material in an electrolytic solution such as sulfuric acid. After the anodization, the washing step is further performed with water, optionally followed by coloring and sealing steps to obtain the product.
A large amount of alkaline waste liquid, in which metal aluminum is dissolved at a dense concentration, is produced in the alkaline etching step. In order to effectively utilize the alkaline waste liquid, aluminum hydroxide is deposited from the alkaline waste liquid. On the other hand, the resultant recovery liquid is reused by returning it as caustic soda to the alkali etching step. The deposited aluminum hydroxide has its water concentration of 12 to 15%, and it is a crystalline aluminum hydroxide called gibbsite. This product has been hitherto used as a material for cement and ceramic industries.
In the anodization step described above, an acidic waste liquid (sulfate waste liquid) dissolved with metal aluminum is also produced. In order to treat the acidic waste liquid, diffusion dialysis method has been hitherto used so that sulfuric acid and aluminum sulfate are recovered. In other cases, an alkaline waste liquid, which is produced by the alkaline etching, has been hitherto mixed with the acidic waste liquid to recover aluminum hydroxide.
Further, aluminum dissolved in a washing liquid also exists in the step of washing with water after the alkaline etching and the steps of washing with water before and after the anodization. The washing liquids are gathered and neutralized, followed by solid-liquid separation to obtain sludge or slime containing aluminum hydroxide. The aluminum hydroxide in the sludge has a high water content, and it is an amorphous aluminum hydroxide in a form of gel. Therefore, the aluminum hydroxide sludge has troubles concerning the treatment and disposal. The sludge contains a large amount of other metal components which are components of the aluminum alloy other than aluminum, and it has been hitherto processed by reclamation, or it has been hitherto processed by dissolving it in a by-product of aluminum sulfate. The aluminum sulfate contains colored ions such as those of copper and nickel having been contained in the aluminum alloy. Therefore, the aluminum sulfate is inferior in added value as compared with the high purity aluminum sulfate produced by dissolving gibbsite. As a result, for example, a problem arises in that the aluminum sulfate can be merely used for usage as a neutralizing aggregation treatment agent for processing the waste water.
The effective utilization and the problems, which relate to the waste liquid and the aluminum hydroxide sludge in the alumite processing as described above, are disclosed in detail in “Technology for Processing Waste (Aluminum Hydroxide Sludge) and Reproducing Resource from Waste” issued by the juridical foundation of Clean Japan Center (February, 1981). Factories for processing and treating alumite are present at not less than 1000 sites only in Japan. The amount of produced sludge exceeds 5000 tons per year. Therefore, the waste liquid, which is produced by the alumite processing or treatment, contains a large amount of valuable components. However, in the present circumstances, it is difficult to consider that such valuable components are sufficiently reused. Further, it is demanded to reuse aluminum scrap and aluminum waste produced from the alumite treatment and from other aluminum-processing sites.
DISCLOSURE OF THE INVENTION
An object of the present invention is to provide a method for reproducing a resource from waste, in which a waste liquid or a sludge containing aluminum as described above is utilized as a raw material for producing a catalyst carrier.
Another object of the present invention is to provide a novel process for producing pseudo-boehmite which serves as a raw material for a catalyst carrier. Still another object of the present invention is to provide a method for producing the catalyst carrier and a method for producing a hydrogenation refining catalyst based on the use of the novel process.
Still another object of the present invention is to provide a novel method for treating alumite including the process of effectively utilizing a waste liquid and an aluminum hydroxide sludge produced from the alumite treatment.
According to a first aspect of the present invention, there is provided a method for producing pseudo-boehmite, comprising the steps of dissolving metal aluminum in an acidic or alkaline aqueous solution to prepare an acidic or alkaline aluminum aqueous solution, and producing the pseudo-boehmite from the acidic or alkaline aqueous solution.
As described in the column of the background art, the pseudo-boehmite, which is the material for producing the alumina carrier for the catalyst, is generally produced by forming aluminic acid by using high purity gibbsite as a starting material, and then reacting the obtained product. The present inventors have found out that the pseudo-boehmite can be produced by reacting, under a predetermined condition, the alkaline aqueous solution or the acidic aqueous solution dissolved with a large amount of metal aluminum discharged in a large amount as a waste liquid from the aluminum-process
Ohashi Yuji
Segawa Hideo
Tsukada Takayuki
LandOfFree
Method of manufacturing pseudo-boehmite does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Method of manufacturing pseudo-boehmite, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Method of manufacturing pseudo-boehmite will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2884657