Aluminum chloride sludges

After removal of aluminum chloride sludge, the reaction mixture is fractionated to recover excess benzene (which is recycled to the reaction vessel), a light alkylaryl hydrocarbon, dodecylbenzene, and a heavy alkylaryl hydrocarbon. 

Modified aluminum chloride catalysts (aluminum chloride sludges, aluminum chloride monomethanolate, aluminum chloride-nitroalkane... 

Because 2,3-dimethylbutane is a very desirable component of aviation gasoline and because aluminum chloride is a particularly suitable catalyst for the production of this hexane by the ethylation of isobutane, much work has been done to develop processes for carrying out the reaction on a commercial scale in continuous flow operation. Excellent results have been obtained with liquid aluminum chloride sludges consisting of aluminum chloride dissolved or dispersed in complexes of aluminum chloride with highly unsaturated hydrocarbons. These sludges are insoluble in the... 

Treatment with aluminum chloride is one of the few chemical methods applied commercially to lubricants in the past 25 years. Aluminum chloride reacts with the undesirable sludge-forming hydrocarbons the complex reaction product is removed by settling. 

In certain reactions, such as the isomerization of butane and the alkylation of isoparaffins, problems of handling hydrogen chloride and acidic sludge are encountered. The corrosive action of the aluminum chloride-hydrocarbon complex, particularly at 70 to 100°C, has long been recognized and various reactor liners have been found satisfactory. 

In the United States, the iron oxide sludge is often discarded. In Germany, however, considerable effort has been expended toward the development of processes whereby the sludge can be converted into useful pigments. The reductions may be carried out so that black, yellow, and red pigments are obtained as an integral part of the process. Addition of salts such as aluminum chloride influences the shade toward yellow. ... 

As has already been indicated hydrogen transfer reactions involving olefinic hydrocarbons lead to the formation of highly unsaturated compounds. These form addition complexes ( lower layer or sludge ) with the catalyst. In this way, crystalline aluminum chloride is converted to a red-brown liquid. Similar red to brown viscous products are obtained when sulfuric acid or hydrogen fluoride is employed. 

Isomerization processes developed slowly because of the low demand for higher octane numbers and operational problems with aluminum chloride, the first catalyst to be developed. Despite high activity at 115-120°C, aluminum chloride has the major disadvantages of the formation of sludges and acid corrosion of equipment. 

In isomerizing butane with aluminum chloride, only a small amount of catalyst-hydrocarbon complex is formed, but pentane and especially hexane produce more complex. Both pentane and hexane tend to crack during treatment and this is the cause of the extensive side reactions. The formation of sludge is inhibited in pentane isomerization by the use of 0.3 to 1.3 weight per cent benzene, and in hexane isomerization, hydrogen is used as an inhibitor. 

Phosphorous removal is most commonly done by chemical precipitation with iron or aluminum compounds, such as ferric chloride or alum (aluminum sulfate). The solids which are produced can be settled along with other sludges, depending on where in the treatment train the process takes place. "Lime", or... 

The metallic impurities present in an impure metal can be broadly divided into two groups those nobler (less electronegative) and those less noble or baser (more electronegative) as compared to the metal to be purified. Purification with respect to these two classes of impurities occurs due to the chemical and the electrochemical reactions that take place at the anode and at the cathode. At the anode, the impurities which are baser than the metal to be purified would go into solution by chemical displacement and by electrochemical reactions whereas the nobler impurities would remain behind as sludges. At the cathode, the baser impurities would not get electrolytically deposited because of the unfavorable electrode potential and the concentration of these impurities would build up in the electrolyte. If, however, the baser impurities enter the cell via the electrolyte or from the construction materials of the cell, there would be no accumulation or build up because these would readily co-deposit at the cathode and contaminate the metal. It is for this reason that it is extremely important to select the electrolyte and the construction materials of the cell carefully. In actual practice, some of the baser impurities do get transferred to the cathode due to chemical reactions. As an example, let the case of the electrorefining of vanadium in a molten electrolyte composed of sodium chloride-potassium chloride-vanadium dichloride be considered. Aluminum and iron are typically considered as baser and nobler impurities in the metal. When the impure metal is brought into contact with the molten electrolyte, the following reaction occurs... 

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