The present invention relates to a process for producing isocyanates in process chains, each of which produce an isocyanate end product via at least one intermediate product, wherein the heat energy liberated in a first production plant in a heat-emitting operation of producing an intermediate product, an isocyanate end product or a catalyst required for a substep of the process chain (first chemical product) is at least partly utilized for generating vapour, in particular water vapour, having a pressure of 1.31 bar.sub.(abs.) to 1.91 bar.sub.(abs.) and a temperature of 107 C. to 119 C. and the thus generated vapour is employed for performing a heat-consuming operation in the preparation of another chemical product (second chemical product) in a second production plant.

The present invention relates to a process for producing isocyanates in process chains, each of which produce an isocyanate end product via at least one intermediate product, wherein the heat energy liberated in a first production plant in a heat-emitting operation of producing an intermediate product, an isocyanate end product or a catalyst required for a substep of the process chain (first chemical product) is at least partly utilized for generating vapour, in particular water vapour, having a pressure of 1.31 bar.sub.(abs.) to 1.91 bar.sub.(abs.) and a temperature of 107 C. to 119 C. and the thus generated vapour is employed for performing a heat-consuming operation in the preparation of another chemical product (second chemical product) in a second production plant.

The invention relates to a production process for polyamines through condensation of aromatic amines with formaldehyde employing at least one solid zeolite catalyst partially or fully ion-exchanged to the protonic form which has been A) alkaline-treated, wherein the alkaline treatment is in case of BEA zeolites carried out in the presence of a pore-directing agent and in case of zeolites other than BEA zeolites in the presence or absence of a pore-directing agent,
or B) acid-treated without any alkaline treatment preceding or following said acid treatment, wherein the acid treatment is effected with an organic acid with chelating function.

The invention relates to a production process for polyamines through condensation of aromatic amines with formaldehyde employing at least one solid zeolite catalyst partially or fully ion-exchanged to the protonic form which has been A) alkaline-treated, wherein the alkaline treatment is in case of BEA zeolites carried out in the presence of a pore-directing agent and in case of zeolites other than BEA zeolites in the presence or absence of a pore-directing agent,
or B) acid-treated without any alkaline treatment preceding or following said acid treatment, wherein the acid treatment is effected with an organic acid with chelating function.

The invention relates to a production process for polyamines through condensation of aromatic amines with formaldehyde employing at least one solid zeolite catalyst partially or fully ion-exchanged to the protonic form which has been A) alkaline-treated, wherein the alkaline treatment is in case of BEA zeolites carried out in the presence of a pore-directing agent and in case of zeolites other than BEA zeolites in the presence or absence of a pore-directing agent,
or B) acid-treated without any alkaline treatment preceding or following said acid treatment, wherein the acid treatment is effected with an organic acid with chelating function.

The invention relates to a production process for polyamines through condensation of aromatic amines with formaldehyde employing at least one solid zeolite catalyst partially or fully ion-exchanged to the protonic form which has been A) alkaline-treated, wherein the alkaline treatment is in case of BEA zeolites carried out in the presence of a pore-directing agent and in case of zeolites other than BEA zeolites in the presence or absence of a pore-directing agent,
or B) acid-treated without any alkaline treatment preceding or following said acid treatment, wherein the acid treatment is effected with an organic acid with chelating function.

The invention relates to a production process for polyamines through condensation of aromatic amines with formaldehyde employing at least one solid zeolite catalyst partially or fully ion-exchanged to the protonic form which has been A) alkaline-treated, wherein the alkaline treatment is in case of BEA zeolites carried out in the presence of a pore-directing agent and in case of zeolites other than BEA zeolites in the presence or absence of a pore-directing agent,
or B) acid-treated without any alkaline treatment preceding or following said acid treatment, wherein the acid treatment is effected with an organic acid with chelating function.

The invention relates to a production process for polyamines through condensation of aromatic amines with formaldehyde employing at least one solid zeolite catalyst partially or fully ion-exchanged to the protonic form which has been A) alkaline-treated, wherein the alkaline treatment is in case of BEA zeolites carried out in the presence of a pore-directing agent and in case of zeolites other than BEA zeolites in the presence or absence of a pore-directing agent,
or B) acid-treated without any alkaline treatment preceding or following said acid treatment, wherein the acid treatment is effected with an organic acid with chelating function.