The present disclosure is a method and system for production of carboxylic based chemicals, including carboxylic acids and salts. A method for producing at oxalic acid may include receiving an anolyte feed at an anolyte region of an electrochemical cell including an anode and receiving a catholyte feed including carbon dioxide and an alkali metal hydroxide at a catholyte region of the electrochemical cell including a cathode. Method may include applying an electrical potential between the anode and cathode sufficient to reduce the carbon dioxide to at least one reduction product and converting the at least one reduction product and the alkali metal hydroxide to an alkali metal oxalate via a thermal reactor. The method may further include receiving the alkali metal oxalate at an electrochemical acidification electrolyzer and converting the alkali metal oxalate to oxalic acid at the electrochemical acidification electrolyzer.