Sustainable preparation of hexamethylene diisocyanate for the production of polyurethane

A process for producing hexamethylene diisocyanate for the production of polyurethane, the process comprising:

• a) provision of hexamethylenediamine which is a process product of a process comprising at least the following steps:
• i) provision of methanol which is a process product of a process comprising at least the following steps:
• i-1) provision of carbon monoxide as a process product of at least a partial reduction of CO2 to CO and/or as a process product of at least a partial oxidation of organic material to CO, wherein at least one organic material is selected from the group consisting of at least one organic, solid compound, methane from a biological source, and mixtures thereof;
• and
• i-2) conversion of the provided carbon monoxide into methanol;
• ii) synthesis of propene from the methanol by at least the following steps:
• ii-1) conversion of the methanol to afford a product mixture containing dimethyl ether, water and methanol;
• and
• ii-2) conversion of a starting material containing dimethyl ether, water and methanol in each case from the product mixture at a temperature of more than 200° C. by contact with a catalyst into propene;
• (iii) synthesis of acrylonitrile from the propene by at least the following steps:
• iii-1) provision of ammonia which is a process product of a process comprising at least the following steps:
• iii-1-1) provision of hydrogen gas as a product of an electrolysis of water;
• and
• iii-1-2) reaction of the hydrogen gas with gaseous nitrogen to afford ammonia;
• and
• iii-2) reaction of the propene with the ammonia to afford acrylonitrile;
• iv) synthesis of adiponitrile from the acrylonitrile by at least the following steps:
• introduction of a mixture containing water, said acrylonitrile and at least one electrolyte salt into a cathode space of an electrolysis cell and contacting the mixture with a cathode having an electrical current applied to it;
• cathodic hydrodimerization of acrylonitrile to form an adiponitrile-containing product mixture;
• and
• discharging of the adiponitrile-containing product mixture from the cathode space of the electrolysis cell;
• and
• v) synthesis of hexamethylenediamine from the acrylonitrile by at least the following steps:
• provision of hydrogen gas as a product of an electrolysis;
• and
• hydrogenation of the adiponitrile with the hydrogen gas to afford hexamethylenediamine;
• b) production of phosgene by at least the following process steps:
• i) provision of carbon monoxide as a process product of at least a partial reduction of CO2 to CO and/or as a process product of at least a partial oxidation of organic material to CO, wherein at least one organic material is selected from the group consisting of at least one organic, solid compound, an organic, liquid monohydroxyalkyl compound, methane from a biological source, and mixtures thereof;
• ii) reaction of the carbon monoxide from step i) with chlorine to afford phosgene;
• and
• c) reaction of the hexamethylenediamine with the phosgene to afford hexamethylene diisocyanate.