Ethyl acrylate mfr. from ethylene and acrylic acid in sulphuric acid - which is recycled after removal of polymerisation initiator in thin film evaporator

Ethyl acrylate (I) mfr. involves (a) reacting C2H4 and acrylic acid in the presence of H2SO4, (b) sepg. the reaction prod. into crude (I) and a H2SO4 residue (II), (c) partial purificn. of (I) by removing material forming light ends, (d) complete purificn. and isolation of (I), leaving a (I)-prod. residue (III), and (e) recycling most of (II) from (b) to (a). The novelty is that the rest of (II) is supplied to an evaporator with distributor brushes or vanes, where it is heated initially to 149-182 (163-177) deg.C and then cooled to 110-138 (115.6-135) deg.C before removal from the process. This treatment of (II) removes polymerisation initiators from the system. L'INVENTION CONCERNE UN PROCEDE DE PRODUCTION D'ACRYLATE D'ETHYLE OU L'ON FAIT REAGIR DE L'ETHYLENE ET DE L'ACIDE ACRYLIQUE EN PRESENCE D'ACIDE SULFURIQUE.SELON L'INVENTION, ON FAIT PASSER LA PARTIE RESTANTE DU RESIDU D'ACIDE SULFURIQUE OBTENU A LA SEPARATION EN ACRYLATE D'ETHYLENE BRUT ET RESIDU D'ACIDE SULFURIQUE, A UN EVAPORATEUR 26 A FILM BALAYE QUI EST CHAUFFE DANS SA SECTION INITIALE DE FACON QUE LE RESIDU D'ACIDE SULFURIQUE ATTEIGNE 149 A 182C ET REFROIDI DANS SA SECTION DE RETRAIT POUR REFROIDIR LE RESIDU D'ACIDE SULFURIQUE A ENVIRON 110 A 138C, ET ON RETIRE L'ACIDE SULFURIQUE REFROIDI DU PROCEDE.L'INVENTION S'APPLIQUE NOTAMMENT A LA PRODUCTION D'ACRYLATE D'ETHYLE.