Aluminum alkyls safety

Severe bums can occur if exposed skin comes into contact with an aluminum alkyl, either neat or in solution. The severity and depth of the bum will increase with increasing exposure time. In case of an accident, rinse the exposed skin with copious amounts of water to hydrolyze any remaining aluminum alkyl, to dilute the reagent, and to cool the skin. Rubber gloves, goggles, and a lab jacket are required when working with aluminum alkyls. A splash-protective face shield and a separate safety shield are also recommended. 

Aluminum alkyls have been produced commercially since 1959 using technology originally licensed by Karl Ziegler. Aluminum alkyls are typically pyrophoric and explosively reactive with water (3, 9, 10). Considering such hazards, it is remarkable that thousands of tons of aluminum alkyls are produced each year and have been supplied for decades to the polyolefins industry worldwide with relatively few safety incidents. (However, see section 4.7.)... 

In general all A1—H and A1—C bonds in organoaluminum compounds react quantitatively at or below room temperature with water and alcohols to form compounds with A1—O bonds. Thus trialkyl alanes with alcohols produce aluminum alcoholates and alkanes. Reaction between water or most of the lower alcohols (methanol, ethanol) and trialkyl alanes with small alkyl groups is usually explosive if the undiluted components are mixed at room temperature. If certain safety precautions are observed, however, it is possible to carry out the hydrolysis (or deuterolysis for analytical purposes) so as to obtain the corresponding hydrocarbons. Ether solutions are particularly advantageous as the etherates of trialkyl alanes react less vigorously than the free compounds. 

Regardless of the type of linear olefin used as the feedstock, there are three different types of alkylation processes currently available to produce LAB. The differences between the alkylation processes are determined by the type of catalyst used. Until 1990, the most widely nsed alkylation process employed HF acid as the Lewis-type catalyst. In this process, liqnid HF acid is used to catalyze the alkylation of benzene with the linear olefins. A second process involves the use of an aluminum chloride (AICI3) slurry as the catalyst. The presence of water with both HF acid and AICI3 acts as a co-catalyst to transform each of these catalysts into active species. The third and newest commercial alkylation process to produce LAB uses a solid bed catalyst, which eliminates the safety, handling, and disposal issues that are otherwise inherent with the other two processes. 

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