CHEMICAL PLANT Russian patent published in 2014 - IPC C07C209/78 C07C209/26 C07C209/82 C07C201/08 C07C209/36 C07C265/14 C07C211/50 

FIELD: chemistry.

SUBSTANCE: chemical plant includes a first process unit, having a reactor for producing nitrobenzene via nitration of benzene to produce a first waste water stream containing nitrobenzene; at least a second process unit, having a reactor for producing aniline by reducing nitrobenzene with hydrogen to provide a second waste water stream containing aniline; an aniline purification apparatus for removing nitrobenzene from aniline, a stripping column for separating aniline from the waste water stream. The first waste water stream is fed into the stripping column below the point of input of the second waste water stream, where said stripping column separates aniline and nitrobenzene from said first and second waste water streams, and the separated aniline and nitrobenzene are fed into said aniline purification apparatus. The stripping column normally used for the plant has n theoretical trays denoted by symbols A1 through An, wherein A1 corresponds to the top tray and An corresponds to the bottom tray; said second waste water stream is fed into the stripping column at theoretical tray Ax, where x is not less than 1, and said first stream is fed into the stripping column at theoretical tray A[y], where [y] is the integer part of the value y, and the value y itself satisfies the equation 0.5*(n+1)+0.5*x<y<0.85*(n+1)+0.15*x. The plant can further include a reactor for producing diaminodiphenylmethane (DADPM) for converting said aniline of said aniline stream into DADPM.

EFFECT: invention enables to obtain products of high quality with a considerable economic effect by avoiding the need to treat each stream separately.

18 cl, 2 dwg, 2 tbl