Improved method for processing magnesium chloride solutions and method for manufacturing carboxylic acids

• Main Authors: Frediansyah, Raymon, De Vries, Johannes Jeichienus
• Format: Patent
• Language: English
• Published: 02.08.2018
• Subjects: ACYCLIC OR CARBOCYCLIC COMPOUNDS; CHEMISTRY; COMPOUNDS OF THE METALS BERYLLIUM, MAGNESIUM, ALUMINIUM,CALCIUM, STRONTIUM, BARIUM, RADIUM, THORIUM, OR OF THERARE-EARTH METALS; COMPOUNDS THEREOF; INORGANIC CHEMISTRY; METALLURGY; NON-METALLIC ELEMENTS; ORGANIC CHEMISTRY

The invention pertains to a method for processing magnesium chloride solutions comprising the steps of - providing an aqueous magnesium chloride solution with a magnesium chloride concentration of 10-30 wt. % to a concentration step where water is evaporated, resulting in a concentrated magnesium chloride solution with a magnesium chloride concentration of 30-50 wt.%, wherein the concentration step is carried out in one or more stages, wherein at least one of the stages is conducted at elevated pressure, - withdrawing the concentrated magnesium chloride solution from the concentration step, and providing it to a thermohydrolysis reactor, the reactor being at a temperature of at least 300°C, - withdrawing MgO from the thermohydrolysis reactor in solid form, and withdrawing a HC1 containing gas stream having a temperature of at least 300°C from the thermohydrolysis reactor, - providing the HC1-containing gas stream having a temperature of at least 300°C to a cooling step, where the HC1-containing gas stream is contacted with a cooling liquid, - withdrawing a HC1-containing gas stream with a temperature below 150°C from the cooling step, - circulating the cooling liquid through a heat exchanger where energy from the cooling liquid is transferred to a heating liquid which circulates from the heat exchanger to the concentration step. The invention also pertains to a method for manufacturing carboxylic acids, which comprises, among other steps, the processing of the magnesium chloride solutions as described above.