Process for the preparation of isocyanates

摘要

Preparation of isocyanate comprises preparing phosgene by reacting chlorine with carbon monoxide, reacting phosgene with at least an organic amine and hydrogen chloride to obtain at least an isocyanate, separating and reconditioning the obtained isocyanate, separating and purifying the hydrogen chloride, preparing an aqueous solution of hydrogen chloride, electro-chemically oxidating at least a portion of the hydrogen chloride solution to chlorine and recycling the chlorine for the preparation of the phosgene.