Acrolein and derivatives

Acrolein is a highly toxic material with extreme lacrimatory properties. At room temperature acrolein is a Hquid with volatiUty and flammabiUty somewhat similar to acetone but unlike acetone, its solubiUty in water is limited. Commercially, acrolein is always stored with hydroquinone and acetic acid as inhibitors. Special care in handling is required because of the flammabiUty, reactivity, and toxicity of acrolein. 

The physical and chemical properties of acrolein are given in Table 1. 

Kirk-Othmer Encyclopedia of Chemical Technology (4th Edition) 

The Reaction. Acrolein has been produced commercially since 1938. The first commercial processes were based on the vapor-phase condensation of acetaldehyde and formaldehyde (1). In the 1940s a series of catalyst developments based on cuprous oxide and cupric selenites led to a vapor-phase propylene oxidation route to acrolein (7,8). In 1959 Shell was the first to commercialize this propylene oxidation to acrolein process. These early propylene oxidation catalysts were capable of only low per pass propylene conversions (ca 15%) and therefore required significant recycle of unreacted propylene (9—11). 

In 1957 Standard Oil of Ohio (Sohio) discovered bismuth molybdate catalysts capable of producing high yields of acrolein at high propylene conversions ( 90%) and at low pressures (12). Over the next 30 years much industrial and academic research and development was devoted to improving these catalysts, which are used in the production processes for acrolein, acryUc acid, and acrylonitrile. AH commercial acrolein manufacturing processes known today are based on propylene oxidation and use bismuth molybdate based catalysts. 

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Propylene Oxidation. The propylene oxidation process is attractive because of the availabihty of highly active and selective catalysts and the relatively low cost of propylene. The process proceeds in two stages giving first acrolein and then acryUc acid (39) (see Acrolein and derivatives). 

The direct oxidation of ethylene is used to produce acetaldehyde (qv) ia the Wacker-Hoechst process. The catalyst system is an aqueous solution of palladium chloride and cupric chloride. Under appropriate conditions an olefin can be oxidized to form an unsaturated aldehyde such as the production of acroleia [107-02-8] from propjiene (see Acrolein and derivatives). 

Chemical Production. Glyciae, DL-methionine, and dl-alanine ate produced by chemical synthesis. From 1964 to 1974, some glutamic acid was produced chemically (48). The synthetic amino acid with the largest production is DL-methionine from actoleia (see Acrolein and derivatives). The iadustrial production method is shown ia the foUowiag (210). 

Acrolein can be obtained by propylene oxidation in a process similar to ammoxidation (109) (see Acrolein and derivatives). 

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