Fine Catalysts Research Articles

An experimental study of the expansion characteristics of gas fluidized beds of fine catalysts

Experimental tests have been carried out on four commercial fine catalysts fluidized by three different gases to characterize the particulate expansion range, the minimum bubbling point, the dense-phase permeability and bubble hold-up in the aggregate regime. The results provide answers to some practical questions regarding the applicability of a recently proposed model of the fluidized state (the ‘particle bed model’) which offers a comprehensive fluid dynamic interpretation of gas and liquid fluidization.

Hydrocracking of Heavy Oils with Fine Powder Catalysts (Part 7)

石油系重質油に含まれる灰分が重質油水素化分解反応の触媒となりうることを明らかにするため, ベネズエラ Morichall 原油ほか3種類の重質油から単離した灰分粉末を触媒として, おのおのの重質油の水素化分解反応を500mlオートクレーブにて行った。灰分触媒はCo, Mo/Al2O3粉末触媒に比べると生成油の性状はやや劣るが, コーキング抑制能に優れ, 重質油の軽質化用触媒として有効であることがわかった。灰分触媒を用いる反応では, アスファルテン分や金属分の多い重質油ほどコーキングしやすい傾向がみられるが, そのような重質油でも, より多くの灰分触媒を用いることにより, 十分なコーキング抑制効果が得られた。

Hydrocracking of Heavy Oils with Fine Powder Catalysts (Part 6)

Hydrocracking of Heavy Oils with Fine Powder Catalysts (Part 6)

Hydrocracking of Heavy Oils with Fine Powder Catalysts (Part 5)

Hydrocracking of Heavy Oils with Fine Powder Catalysts (Part 5)

Hydrocracking of Heavy Oils with Fine Powder Catalysts (Part 4)

Hydrocracking of Heavy Oils with Fine Powder Catalysts (Part 4)

Hydrocracking of Heavy Oils with Fine Powder Catalysts (Part 3)

Hydrocracking of Heavy Oils with Fine Powder Catalysts (Part 3)

Hydrocracking of Heavy Oils with Fine Powder Catalysts (Part 2)

Hydrocracking of Heavy Oils with Fine Powder Catalysts (Part 2)

The silver catalyst in the hydrophobic oxygen electrode

Ten sorts of silver powder were tested as the catalysts for hydrophobic air electrodes in an alkaline electrolyte. The fine grain catalysts meet the demands of the electrodes better than the catalysts with large surface area which proved not to be satisfactory. The catalyst prepared by reduction of the aqueous suspension of a solid silver salt has the best properties. Electrochemical electrode behaviour is improved by using pure oxygen. The characteristics of some silver catalysts in hydrophilic electrodes were also determined.

Hydrocracking of Heavy Oils with Fine Powder Catalysts (Part 1)

Hydrocracking of Heavy Oils with Fine Powder Catalysts (Part 1)

The silver catalyst in the hydrophobic oxygen electrode

Ten sorts of silver powder were tested as the catalysts for hydrophobic air electrodes in an alkaline electrolyte. The fine grain catalysts meet the demands of the electrodes better than the catalysts with large surface area which proved not to be satisfactory. The catalyst prepared by reduction of the aqueous suspension of a solid silver salt has the best properties. Electrochemical electrode behaviour is improved by using pure oxygen. The characteristics of some silver catalysts in hydrophilic electrodes were also determined.

Determination of surface areas by an improved continuous flow method

Abstract : The determination of the surface areas of powders is of considerable importance for the quality control of composite propellants. For many years satisfactory control has been achieved by the use of an air permeability method but this was found unsuitable for very fine ammonium perchlorate and solid burning rate catalysts which are being used to an increasing extent in fast-burning compositions. Of the various methods considered for measuring the surface areas of these very fine powders, the continuous flow gas adsorption method appeared promising but had several disadvantages in operation. The report describes modification to the method which have removed the disadvantages. (Author)