Consumptions per ton xylitol
Name | Consumptions | Unit |
Crystalline xylose | 1.10 | ton |
30% HCl | 33.5 | Kg |
30% NaOH | 28.0 | Kg |
Active carbon | 6.50 | Kg |
Hydrogen | 19.0 | Kg |
Nickel alloy catalyst | 5.50 | Kg |
Magnesium powder | 0.40 | Kg |
Steam(6Kgf/cm2 gauge pressure) | 3.80 | ton |
Electricity | 400 | Kwh |
Process water(conductivity<200μS) | 10.0 | ton |
Waste water
Waste water per ton xylitol | gap | average |
Waste water amount |
| 10t |
PH | 2～11 | 5 |
COD | 800～3000 | 1900 |
Budget: 50TPD xylitol workshop needs USD 7,246,000 by using crystalline xylose. By product xylose mother liquor （60%DS）115Kg.
1. Dissolve: put a certain crystalline xylose to a certain amount of water, open the agitator and make it soluble in the water completely to have xylitol of 50% concentration.
2. PH adjusts: to add sodium hydrate to adjust the PH value to 7.5-7.8.
3. Hydrogenation: xylitol is sent to high pressure reactor to react with hydrogen by the nickel and aluminum alloy catalyzer under 120℃t and 80atm, xylose is hydrogenated to xylitol.
4. Decoloring: there is sugar syrup in the hydrogenated liquid which will generate colored matter by the high temperature during hydrogenating, then to input powder active carbon, which will absorb the colored matters.
5. Press filtering: to use the frame press filter to remove the powder active carbon and its absorbed colored impurities until the hydrogenating liquid is transparent, part of nickel and aluminum alloy catalyzer is removed.
6. Ion exchange: besides of cation and anion, there are still some inorganic impurities in the Hydrogenated liquid which are also removed by ion exchanging columns.
7. Concentrating: Hydrogenated liquid is concentrated by vacuum evaporator which can increase the DS from 50% to 70%.
8. Concentrating：As the water in xylitol solution is evaporated in vacuum crystallizer, less and less soluble xylitol is in the water, so insoluble part is separated from solution as crystals.
9. Centrifuging separating: massecuite enters separator, high purity crystalline xylitol remains in the screen basket in separator, the solution is concentrated as mother liquid, after cooling it reach 75% DS xylitol mother liquid.
10. Drying: the high purity crystalline xylitol still contains a certain amount of water, so it is going to be drying in 85% temperature until the moisture content reach the standard
11. Packing: after drying, crystalline xylitol is measured and sealed in special package, after quality testing the product is sold.
