Abstract: A method and a continuous process for producing two isocyanates by reacting a first amine with phosgene in a stoichiometric excess in the gas phase to produce a first isocyanate. The excess phosgene is subsequently recovered and recirculated back to react with a second amine to produce a second isocyanate. In an embodiment, both fresh and recycled phosgene may be used in reacting each respective amine to produce an isocyanate. The amine streams contain two different concentrations of hydrogen chloride: one may be between 0.0 and 0.1%, and another may be between 1 and 5% by weight.

Abstract: The invention relates to a method for producing two isocyanates by reacting a first amine with phosgene in a stoichiometric excess in the gas phase to produce a first isocyanate, wherein the excess phosgene is subsequently recovered and recirculated back to react with a second amine to produce a second isocyanate. In another embodiment, both fresh and recycled phosgene may be used in reacting each respective amine to produce an isocyanate. The amine streams may be optimized to contain different concentrations of hydrogen chloride, as required for the production of two different isocyanates.