Question

How is maleic anhydride produced?

Answer 1

Hint : Maleic anhydride is an organic compound. ${C_2}{H_2}{(CO)_2}O$ is the formula for maleic anhydride. It is maleic acid's acid anhydride. It has an acrid odor and is colorless or white. It's made on a wide scale in the manufacturing sector for use in coatings and polymers.

Complete Step By Step Answer:
- The vapor-phase oxidation of n-butane produces maleic anhydride. The backbone is dehydrogenated and the methyl groups are converted to carboxylate.
- The combination of benzene and butane is pumped into a stream of hot air and moved into a high-temperature catalyst bed. To avoid the mixture from igniting, the air-to-hydrocarbon ratio is controlled. Vanadium pentoxide and molybdenum trioxide are the catalysts used for the benzene route, whereas vanadium phosphate is used for the butane route:
${C_4}{H_{10}} + 3.5{O_2} \to {C_4}{H_2}{O_3} + 4{H_2}O{\text{ }}\Delta H = - 1236kjmo{l^{ - 1}}$
Complete combustion of the butane, which is twice as exothermic as partial oxidation, is the main competing method. Older methods used naphthalene as a feedstock, whereas newer methods use o-xylene.
- Maleic anhydride has diverse chemistry, owing to its widespread availability and bifunctional reactivity. Maleic acid, $Cis - HOOC - CH = CH - COOH$ , is generated when it hydrolyzes. The half-ester is formed when alcohols are used, for example, $Cis - HOOC - CH = CH - COO{H_3}$ .
- It has various names such as
Furan-2,5-dione
cis-Butenedioic anhydride
2,5-Furanedione
Maleic acid anhydride
Toxilic anhydride

Note :
- Maleic anhydride is used as a base in Diels-Alder reactions. It was first used in 1928 for research on the reaction between maleic anhydride and 1,3-butadiene, because of this the Nobel Prize was awarded to Otto Paul Hermann Diels and Kurt Alder in 1950.
- Unsaturated polyester resins account for around half of the world's maleic anhydride production.