Oxalic Acid (99%) - Taiwan

Brief Overview
Oxalic acid is an organic compound with the chemical formula C2H2O4. It is a dicarboxylic acid, and is a reducing agent. Oxalic acid exists in two forms depending on the hydrogen bonding: a chain-like structure or a sheet-like structure. The anhydrous form of oxalic acid is both acidic as well as hydrophilic. Oxalic acid is a colorless liquid and it is crystalline in structure. It is also soluble in water. It occurs in nature in wood-sorrels, spinach (broccoli, cabbage, and Brussels sprouts), Rhubarb leaves and parsley. Some bacteria produce oxalic acid through the oxidation of carbohydrates. Plants that belong to a genus called fenestraria produce crystalline oxalic acid to help in transmitting light for photosynthesis.
Manufacturing Process
Oxalic acid is manufactured by the oxidation of carbohydrates or glucose using nitric acid or air, in the presence of a catalyst (vanadium pentoxide) for commercial use. The raw materials used for the production can be molasses/cellulosic wastes and nitric-sulphuric acid mixture. The process starts with a batch process, where the nitric acid is added to the molasses or cellulosic wastes. This mother liquor is then fed to a reactor and sulphuric acid is added to increase the temperature of the reactor. There are cooling coils present, through which a coolant is circulated to reduce the temperature. Then nitric acid is added into the reactor, followed by the gradual addition of sugar. The rate of adding sugar is increased gradually, to avoid rapid increase in the temperature. The oxalic acid that is formed, is centrifuged and then purified by recrystallization using water. The recrystallized product is further centrifuged and dried. The reaction can be written as below:
C6H12O6 + 6 HNO3 → 3 H2C2O4 + 6 NO + 2 H2O