Germany - Cellulose - base for paper sourcing

1. Cellulose as a base for paper
production

2. What paper is used for
35
51
7 6
graphics
packaging
hygiene
specific use

3. Stages in the production
- Sourcing cellulose from wood fibres
- Eliminating the bark
- Chopping up the timber into chips
- Boiling the chips in sulfur base or acid to
expose cellulose
- Eliminating lignine (the glue within the wood)
- Pressing and drying the paper

4. Inconvenient truths
• The energy balance of producing 1 t of
paper equals that of producing 1t of steel
• In 2008, 18.500.000 t of CO2 were emitted
in paper production

5. Sources of cellulose worldwide
20
40
25
15
Domestic cellulose
Scandinavian
Brazilian
rest of the world

6. Kinds of raw materials
• Fibres: Saw dust, wood chips, pellets, waste
papers and other plant fibres
• Glues and Coatings: animal resins, plant resins,
waxes
• Fillers: Caoline, talcum, plaster, chalk, other
colorants
• Additives: Water, colorants, de-foamers,
chemicals changing the surface properties of
fibres and water

7. Raw materials: two groups
• Primary Fibres: Original raw materials first
used in production
• Secondary Fibres: Waste paper, materials
for recycling that have been used before

8. Plant fibres source of cellulose

9. Cellulose
• Part of the group of carbohydrates
• Cellulose is a polysaccharide
• Molecular basis:
• (C6H12O6)n
• Smallest unit is glucose, which can be
extended into polymers

10. Cellulose structure:
Polysaccharide

11. Dimensions of Cellulose

12. Cellulose in paper

13. Production of of paper from pine
wood by
sulfate procedure
Pressurized container with wood pellets
or chopped-up stems.
Pressure of 7-10 bar
Sodium base (NaOH)
Sodium sulfidNa2S
Natriumsulfate (Na2SO4)

14. Separation of Cellulose:
Destroying the lignine
• Sulfid-Anion friction(nucleophile)of the
Lignine
Water based black
base

15. Remains after filtration
• Remains can be separated by filtration.
• Base partly evoporates as it is heated
• Produces Thioles (an alcoholic group in
which oxygene have been replaced by
sulfur)

16. Byproducts gained
• Sodium lignine  used for plastics
• Black base used for fertilizers

17. Byproducts: Oils and sugars
30 kgs of oils can be sourced from 1 t of
cellulose, such as terpentine and various wood
sugars
> 3% can be re-used as oils/sugars

18. Recycling resins:
• Paper glue,
• Phenole resins
• Dispersants, stains etc.

19. Goal: Improvement of the total
balance
• Recycling all materials used
• Improving water balance
• Improving energy balance through catalysts
(such as anthrachinone)
• Sulfate procedure is less sustainable than
sulfite procedure
• Yet, only 85% of the global paper
production are feasable through this
procedure

20. More sustainable alternative:
Sulfite procedure
• In the sulfite procedure, wood it divided by
• cations
• Lignine is destroyed by ionic exchange
• As a result, it can be solved in water
Procedure pH-value cations
acid 1,2−1,8 Ca2+, (Mg2+, Na+, NH4
+)
bisulfite 3,5−5,5 Mg2+, (Na+, NH4
+)
neutral 5−7 Na+, NH4
+

21. Problem: heavy use of sulfur
• Per 1000kg of cellulose, 90kg of sulfur and
and 5 solid meters of wood are used
• Sulfur is harmful to mammals and humans
as it can destroy cell structures and cause
cancer

22. Advantages
• A very pure fibre is the product
• Many of the chemicals used can be recycled

23. Disadvantages
• High use of energy (Regain through
combustion and re-use of the heat produced
• Risks through massive use of sulfur
• THANK YOU 