| 摘要 |
<p>An aq. soln. contg. 25-75 wt.% partially inverted sucrose is admixed with a Ni hydrogenation catalyst at 1:0.006-0.020 by wt. The suspension thus formed is brought into contact with H2 under pressure to yield mannitol. The operation is carried out at >=100 degrees C, pref. 140-170 degrees C, and at a pressure of 105 atm. in two separate stages. In the first stage the pH is 8-12 and in the second 6. The first stage is continued until all the fructose present, and the second until substantially all the sugar present has been hydrogenated. For pref. embodiments an alkali or alkali(ne earth) metal hydroxide is used in the first stage and an org. or inorg. acid, esp. H2SO4 citronic acid, acetic acid or gluconic acid is used in the second stage. The advantage of the process consists in that high reaction velocities are obtained as the pref. operating temps.</p> |
