A nitric acid oxidation process was developed to produce oxalic acid from sugar beet molasses. The important parameters affecting the yields were found to be air flow rate, temperature, the amount of V2O5 catalyst and the concentrations of molasses. H2SO4 and HNO3. A maximum yield of 76.0% was obtained. The nitrogen oxides (NO.) released were absorbed in concentrated sulphuric acid and reused in the following reactors giving, under similar conditions. slightly lower yields. Thus it was possible to reduce-nitric acid consumption and to prevent air pollution. Meanwhile, it. was possible to reduce the unit cost of raw material for oxalic acid production. A maximum 74.9% of theoretical yield was obtained by Using the absorption solution and filtrate.