Method for producing hydrogen chloride or an aqueous solution thereof using untreated salt water, thus produced product, use of the product and electrodialysis system

A first product and a second product produced according to a method comprising the steps of:

• furnishing a first electrolyte, wherein the first electrolyte contains chloride ions having an initial concentration of chloride ions;
• carrying out a first electrodialysis, wherein:
• the first electrolyte is subjected to a first cathodic reduction from which results a first catholyte;
• the concentration of chloride ions drops in the first electrolyte;
• a concentration of hydroxide ions increases in the first electrolyte;
• and
• the first product in a form of hydrogen chloride or an aqueous solution of hydrogen chloride is produced;
• processing at least a partial quantity of the first catholyte, from which results a second electrolyte, wherein:
• the untreated saline water is used;
• the concentration of chloride ions increases in the first catholyte;
• and
• the concentration of hydroxide ions drops in the first catholyte;
• furnishing a third electrolyte, wherein the third electrolyte contains chloride ions, and wherein the third electrolyte comprises at least a partial quantity of the second electrolyte;
• and
• carrying out a second electrodialysis, wherein:
• the third electrolyte is subjected to a second cathodic reduction from which results a second catholyte;
• the concentration of chloride ions drops in the third electrolyte;
• a concentration of hydroxide ions increases in the third electrolyte;
• and
• the second product in a form of hydrogen chloride or an aqueous solution of hydrogen chloride is produced.

An electrodialysis system comprising:

• a storage vessel;
• and
• an electrodialysis cell comprising:
• an anion exchanger membrane;
• a cation exchanger membrane;
• a cathode;
• and
• an anode;
• and
• a reaction vessel;
• wherein:
• the storage vessel is configured to store a first electrolyte, wherein the first electrolyte contains chloride ions having an initial concentration of chloride ions;
• the electrodialysis cell is configured to:
• receive the first electrolyte from the storage vessel;
• and
• carry out a first electrodialysis, wherein:
• the first electrolyte is subjected to a first cathodic reduction from which results a first catholyte;
• the concentration of chloride ions drops in the first electrolyte;
• a concentration of hydroxide ions increases in the first electrolyte;
• and
• a first product in a form of hydrogen chloride or an aqueous solution of hydrogen chloride is produced;
• the reaction vessel is configured to:
• receive at least a partial quantity of the first catholyte;
• and
• process at least a partial quantity of the first catholyte, from which results a second electrolyte, wherein:
• an untreated saline water is used;
• the concentration of chloride ions increases in the first catholyte;
• and
• the concentration of hydroxide ions drops in the first catholyte;
• the storage vessel is further configured to receive at least a partial quantity of the second electrolyte;
• and
• the electrodialysis cell is further configured to:
• receive a third electrolyte from the storage vessel, wherein the third electrolyte contains chloride ions, and wherein the third electrolyte comprises at least a partial quantity of the second electrolyte;
• and
• carry out a second electrodialysis, wherein:
• the third electrolyte is subjected to a second cathodic reduction from which results a second catholyte;
• the concentration of chloride ions drops in the third electrolyte;
• a concentration of hydroxide ions increases in the third electrolyte;
• and
• a second product in a form of hydrogen chloride or an aqueous solution of hydrogen chloride is produced.