Aluminum chloride storage

Many chlorinated hydrocarbons react readily with aluminum in the so-caHed bleeding reaction. A red aluminum chloride—chlorinated hydrocarbon complex is formed. Storage of uninhibited chlorinated solvents in aluminum vessels results in corrosion in a short period of time. Proprietary organic inhibitors permit commercial use of reactive solvents such as 1,1,1-trichloroethane and trichloroethylene for cleaning of aluminum. 

In the presence of aluminum, oxidative degradation or dimerization supply HCl for the formation of aluminum chloride, which catalyzes further dimerization to hexachlorobutene. The latter is decomposed by heat to give more HCl. The result is a self-sustaining pathway to solvent decomposition. Sufficient quantities of aluminum can cause violent decomposition, which can lead to mnaway reactions (1,2). Commercial grades of trichloroethylene are stabilized to prevent these reactions in normal storage and use conditions. 

Polymerization of ethylene oxide can occur duriag storage, especially at elevated temperatures. Contamination with water, alkahes, acids, amines, metal oxides, or Lewis acids (such as ferric chloride and aluminum chloride) can lead to mnaway polymerization reactions with a potential for failure of the storage vessel. Therefore, prolonged storage at high temperatures or contact with these chemicals must be avoided (9). 

Toluene and olefinic stock from storage are pumped (at 80°F) separately through individual driers and filters into the alkylation reactor. The streams combine just before they enter the reactor. The reactor is batch operated 4 hr/cycle it is equipped with a single impeller agitator and a feed hopper for solid aluminum chloride which is charged manually from small drams. The alkylation... 

Several of the starting reactants, such as acid anhydrides, acid chlorides, and alkyl halides, are susceptible to hydrolysis. The absorption of moisture by these chemicals results in the production of compounds that are less active, require more aluminum chloride for condensation, and generally lead to lower yields of desired product. Furthermore, the ingress of moisture into storage containers for these active components usually results in corrosion problems. 

Anhydrous aluminum chloride needs to be stored in iron drums under conditions that ensure the absence of moisture. When, however, moisture contacts the aluminum chloride, hydrogen chloride is formed, the quantity of hydrogen chloride thus formed depends on the amount of water and the degree of agitation of the halide. If sufficient moisture is present, particularly in the free space in the container or reaction vessel or at the point of contact with the outside atmosphere, then hydrochloric acid is formed and leads to corrosion of the storage container. 

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