| 摘要 |
<p>Malic acid is prepared by dissolving in water, converter gases containing maleic acid obtained by the vapour phase catalytic oxidation of an organic compound, ageing the resulting solution in contact with oxygen or oxygen-containing gas at a temperature of at least 40 DEG C. for at least two hours, removing solid impurities from the aged solution, and heating the resulting solution under superatmospheric pressure in a closed system to convert the maleic acid to malic acid.</p> |
