Benzene → Nitrobenzene

Participants

Reaction Steps

A sulfuric acid stream (11)=(a.2.1), a nitric acid stream (12)=(a.3.1) and a fresh benzene stream (13)=(a1.1) are fed into a reactor (1). Once all the nitric acid has reacted with the benzene to give nitrobenzene under adiabatic reaction conditions, the reaction product (14), now at a temperature of approx. 130° C., is fed into a phase separation apparatus (2), in which the reaction product (14) separates into an organic phase ((15)=(b.2.1)=crude nitrobenzene, comprising benzene and low boilers in addition to nitrobenzene) and an aqueous phase ((16)=(b.1.1)=waste acid, still comprising small proportions of nitrobenzene and benzene in addition to sulfuric acid). The aqueous phase (16), comprising mainly sulfuric acid, is subjected to a flash evaporation of water in the evaporator (3) by sudden pressure reduction, and is thereby concentrated. The concentrated sulfuric acid (17) is stored in the sulfuric acid tank (4) until it is re-used. After separation in the phase separation apparatus, the crude nitrobenzene (15)=(b.2.1) is cooled to approx. 50° C. in the crude nitrobenzene cooler (5) and fed into the washer (6).

Provenance & Evidence