Bayer Aktiengesellschaft

Manfred Niese

Theodor Pfister

Rolf Putter

Peter P Wenzl

Guido Skipka

Hans-Ulrich Alles

Gert Randau

A process for controlling an installation for the production of chemical substances sub-divides the process control into control regions which are controlled in a decentralized manner and in which a closed divisional function is carried out independently in each case. The working condition of a control region is determined by operating types which may be initially given and by a limited number of discrete operating values. The process parameters determining the control region condition are allocated to each operating value in one formulation. These parameters are adjusted by means of suitable devices. In the event of deviations of a parameter, the other formulation parameters are not adapted, but the procedure is interrupted if the permissible parameter limits are exceeded. Increases in the operating values are only permissible from a quasi-stationary working condition which is characterized by a normal signal formed from the process measurement values. In several control regions, the necessary flexibility is secured by a flow decoupling by means of buffers. Similar control regions are combined into groups, and different groups are combined into main groups. Groups and main groups are controlled together and are decoupled from one another by strategic buffers.

Structured design and decentralized control of production installations

A process for the preparation of 4-amino-3-methyl-phenol from 4-nitroso-3-methyl-phenol, which comprises contacting said 4-nitroso-3-methyl-phenol with iron in an acid aqueous medium at a temperature of 20.degree. to 100.degree. C. said medium having pH in the range from 2 to 6.5.

Process for the preparation of 4-amino-3-methyl-phenol

A process for the preparation of 1-amino-2-ethoxy-naphthalene-6-sulphonic acid from 2-hydroxy-naphthalene-6-sulphonic acid which comprises:

Growing community of inventors

Leverkusen, Germany

Manfred Niese