Patent ID: 11225546

Abstract:
A process for preparing an isocyanate product includes providing a phosgene inlet stream and an amine in solvent inlet stream to a phosgenation mixer, the amine in-solvent inlet stream including one or more amines and one or more inert solvents, and during steady state operation compensating for a fouling pressure drop increase by decreasing a pressure drop in the phosgenation mixer over a time period divided into at least a first period of time T1 and a second period of time T2 that is subsequent to the first period of time T1. During the second period of time T2 an amine concentration of the one or more amines in the amine-in-solvent stream is higher than during the first period of time T1, and during the second period of time T2 a phosgene-to-amine ratio value in the phosgenation mixer is higher than during the first period of time T1.