Patent ID: 7813839

Claim:
A method for controlling an isocyanate production process conducted in a production facility comprising a) at least two incoming streams comprising: (1) a phosgene stream comprising phosgene and (2) a solvent stream comprising solvent b) at least one exit stream containing produced isocyanate and c) at least one inner recycling stream comprising adjusting the phosgene stream amount and/or the solvent stream amount by means of regulating controls to control at least one of the at least one exit stream's quality and/or amount and in which the phosgene stream is fed to a solution unit, further comprising: I. feeding an amine solution stream comprising a mixture of an amine and a solvent to a phosgene solution stream to form a combined stream comprising amine solution and phosgene solution, II. feeding the combined stream to a reactor, III. reacting the amine in the combined stream with a molar excess of phosgene based on the amino groups present to form an isocyanate-containing product stream which is fed from the reactor to a separator, IV. separating the product stream in the separator into (i) at least one exit stream comprising the isocyanate (ii) at least one resource stream comprising solvent, and (iii) a recycle stream comprising mainly phosgene and/or HCl, V. feeding the recycle stream and the solvent stream to a recovery unit for recovering phosgene, to form a recovery stream comprising phosgene and solvent, and VI. feeding the recovery stream from the phosgene recovering unit to the solution unit.