Describes about the paper production and pollution arises due to processing and how to manage pollution.

1. SUBMITTED
BY
KUNDAN KUMAR DAS
M.TECH, 2ND SEMESTER
ITER, SOA UNIVERSITY
PULP AND PAPER INDUSTRY:
PROCESS, WASTE AND ITS MANAGEMENT

2. INTRODUCTION
The Indian Paper Industry is among the top 12 Global players
today,
13.5 Million tones annual with an estimated turnover of Rs.
35000 Cores.
But there has been a tremendous expansion in this industry during
last 25 years.

3. INDIAN PAPER INDUSTRY SCENARIO…..
 Types of paper
I. Industrial grades,
II. cultural grades
III. specialty papers.
Raw materials
I. Wood based
II. Agro based
III. Waste paper based

5. SIMPLIFIED FLOW DIAGRAM OF INTEGRATED
MILL
Input of raw materials
PULPING

6. MAJOR INPUTS FOR PULP PRODUCTION
Fibre
softwood
hardwood
non wood fibres
recovered/recycled fibre
Chemicals
Energy
water
List of materials Cellulose (%)
Lignin (%)
Wood
 Coniferous 40-45
26-34
 Deciduous 38-49
23-30
Non wood
 Rice Stalk 28-48
12-16

7. WOOD PREPARATION (DE-BARKING & CHIPPING)
Debarking is the process of removing bark from wood.
 After de-barking the logs are chipped by multi knife chippers into suitable
sized pieces and
screened to remove large chips.
De-Barking process:
Two types
I. Drum Debarker:
(a) Slightly inclined and rotating drum
(b) Used for small diameter log.
II Hydraulic Debarker:
(a) Uses high pressure water jet.
(b) Applicable for large diameter logs.

8. De-Barking process
Chipping process

9. COOKING/PULPING
Pulp is a cellulose fibrous material prepared by chemically or mechanically
from which paper is manufactured.
Pulping process can be divided into three types:
Mechanical pulping:
(i) Stone ground wood
(ii) Refiner ground wood
Chemical pulping:
In this process chemicals are used to separate the cellulose from
the lignin. This creates pulps with different properties that can be used for higher
quality paper.
Solvent pulping:
I. Lignocellulosic feedstock is contacted with organic solvents such as
acetone, methanol, ethanol, butanol, ethylene glycol, formic acid or acetic
acid.
II. Solvent pulping provides 4 – 5 % higher yield than cracked pulp.
cooking process: where the main part of the delignification takes
place to yield pulp. Here the chips are mixed with white liquor to produce
pulp.

10. KRAFT PULPING
Sulfate or Kraft pulping was invented in Germany in 1884 and widely used.
Kraft pulping relies on a combination of heat, mechanical and chemical
pulping to convert the wood into a smooth, soft pulp suitable for use in paper
making.

11.  Na2SO4 is added to the cooking liquor. So its common name is sulfate
process.

12. Advantages:
It can be used with virtually all wood species.
The recovery process for chemicals is well established.
The pulp has very good strength.
Dis-Advantages:
Pulp is yield is low 45-50%
The equipment used for chemical recovery is extensive and costly to install.
Fairly complicated process.

14. FUNCTIONAL ROLE OF VARIOUS PROCESS
Chipper Bin:
In this bin, with the help of heavy knives wood logs were reduced to size 2-
5 cm.
Digester Tower/cooking:
It is about 25-30 m tall.
chips are preheated with turpentine and non-condensable gases.
For controlling digestion temperature cooking liquor is withdrawn and circulated
through heat exchanger.
Digestion is basically done to remove lignin and non-cellulosic content.
Cooking time is one and half hour at 170°c.
To avoid mechanical weakening of fibers, digested chips are cooled with recycled
black liquor.
Temperature is maintained about at 140-180°c. and at 10atm pressure.

15. Blow Down Valve:
In this valve reduce the pressure of stream from 80atm to 1
atm.
Blown Tank:
In this heat is recovered in the form of steam from hot pulp
slurry and this steam is used for preheating the chips.
Black liquor is recycled back to digester for cooling the
digested chips
Screen:
Pulp is screened to remove wood knots and undigested
residues.
by passing the pulp over pulp screens equipped with fine holes or slots
Series of filters for pulp washing deinking:
pulp is filtered to separate black liquor chemical
recovery plant

16.  The centrifugal cleaners removes unwanted particles from pulp and
paper stock by a combination of centrifugal force and fluid shear.
 All centrifugal cleaners work on the principle of a vortex generated by a
pressure drop to develop centrifugal action.
Necessary of pulp washing
The dissolved chemicals interfere with the downstream processing of the
pulp
The chemicals are expensive to replace
The chemicals (especially the dissolved lignin) are detrimental to the
environment
DE-INKING PLANT STAGES

17. BLEACHING
 Bleaching involves removing virtually all of the lignin that still remains after cooking.
To make paper whiter and free from lignin content.
In practice, there are two separate "bleaching" process steps:
Oxygen delignification
Pulp phenolic group of lignin ionized
NaOH
High pH
O2
O2
Aromatic part of the lignin is partly destroyed
Disadvantage
Polymer chain of cellulose
NaOH
O2
Breaks down cellulose
Reduced
pulp
strength
Therefore, magnesium salt is added to inhibit the ion activity and cellulose
fibre degradation.

18. Final bleaching
The final bleaching is always carried out in several stages to
improve the efficiency of the chemicals used, and to decrease the strength loss of
the pulp.
The chemicals used are:
Chlorine
Chlorine dioxide
Sodium hypochlorite
Oxygen
Peroxide
Ozone

19. Lignin
content
decreases.

20. PAPER MAKING
pulp fibres are mechanically and chemically treated, formed into a dilute
suspension,
spread over a mesh surface,
The water removed by suction,
And the resulting pad of cellulose fibres pressed and dried to form paper

22. Beater:
 It mechanically disintegrates the pulp fibres to make paper stronger, uniform dense
etc.
To increase brightness, flexibility and softness.
Jordan:
It is a conical refiner.
In this part pulp is deformed, defibred and dispersed.
Web Forming:
Pulp fibre are arranged into web like structure.
Shaking motion is provided for better interlocking of fibres on mat.
Pressing:
Pressing is done to remove free water and about 60-65% water content is reduced.
Drying:
Excess amount of water is removed here by smoothing rolls and steam heated
metal drying rolls.
Finishing:
Paper is passed through a series of calendaring rolls for producing smooth paper.

23. Environmental problems

24. AIR EMISSIONS:
Emissions:
Air emissions like sulphur dioxide, nitrous oxides, methanol, polycyclic
organic matter, phenol and chlorinated phenolics, dioxins, furans and other
chlorinated compounds.
Hydrogen Sulfide:
 Hydrogen sulfide is a toxic gas that smells like rotten eggs.
 At elevated levels, it can cause irritation to eyes and damage respiratory
system.
Dioxins and Furans:
 The most toxic compound is 2,3,7,8-tetrachlorodibenzo-p-dioxin
 Mutagenic and carcinogenic
 uses chlorine can change or generate chlorinated dioxins and furans.
 White Paper bleaching uses Chlorine.

25. WATER EMISSION
Reduction of Wastewater:
 Reduce the demand for the high quality bright-white paper.
 For “lower quality” papers use a combination of other chemicals in the
bleach process .
Wastewater releases:
The most common organic pollutants are suspended solids:
Dissolved organic compounds such as lignin compounds, carbohydrates, starch
and hemi-cellulose.
Chlorinated organics are found if elemental chlorine is used in the process.
 chlorinated phenolics,
dioxins, furans,
 phosphates
 suspended sediments.

26. SOLID WASTE
 solid waste such as sludge derived from their pulping and
bleaching operations.
Dirty wood chips or fibers as well as bark.
The broken, low-quality fibres are separated out to become waste
sludge.

27. ENERGY USE
 It is one of the largest producers of greenhouse gas (GHG)
emissions like CO2, CH4, etc.
 The only oil consumer is the causticing oven, which however can be
replaced with bio-fuel.
 Over the past few years, the pulp and paper industry has
considerably reduced its GHG emissions by introducing energy
conservation projects.
 A paper mill requires between 400 and 1000 kWh electricity/ton
paper and 4 – 8 GJ heat/ton for drying in the paper machine.
 In an integrated pulp and paper mill this energy is provided from the
recovery boiler.

28. CLEANER PRODUCTION MEASURES

29. GENETICALLY MODIFIED TREES
 It has been possible to use genetic
engineering to modify lignin content and/or
composition in poplars
ADVANTAGES OF GENETICALLY MODIFIED
TREES
Genetic modifications improved characteristics,
allowing easier delignification, using smaller amount
of chemicals, while yielding more high-quality pulp.
Owing to the genetic modification savings in
energy and chemicals..

30. WOOD YARD
Avoiding hydraulic debarking
Reusing leachate water.
Co-production from bark
Burning bark
PULP PRODUCTION
Water reuse from evaporators
Repulping the rejects from screening
Pulp centrifuging
Sludge utilization
Air emissions control devices

31. CHEMICAL RECOVERY
Using of new technologies
Using light gas strippers and gas collection systems
Air emissions control devices
Providing spill containment and collection system.
BLEACHING
Avoiding chlorine bleaching
Continuing research on biotechnological bleaching and electrochemical
bleaching

32. PAPER PRODUCTION
Adjustment of edge cutter
Use of soft water as a boiler feed water
Recycling water
PRODUCTS PROCESS AND RECYCLING
Increasing recycling rates
Possibility for easy packaging recycling
Using “green” fuel for transportation

33. RECYCLING
In Europe an average of 56% of used paper is recovered. The
recycling process includes following stages:
– Sorting
– Dissolving
– De – inking
– Mixing
– Papermaking process
Raw materials:
 Keeping chemical inventory to a minimum and buying small containers of
infrequently used materials.
 Labelling storage area for hazardous substances.
 Providing spill containment and collection systems during storage

34. POLLUTION PREVENTION AND CONTROL
 Use energy-efficient pulping processes where- ever feasible.
Acceptability of less bright products should be promoted.
Minimize the generation of effluents through process modifications and recycle
wastewater, aiming for total recycling.
 Minimize sulfur emissions to the atmosphere by using a low-odor design black
liquor recovery furnace.
 Recovering the cooking chemicals by recausticizing the smelt from the recovery
furnace.
 Minimize unplanned discharges of wastewater and black liquor, caused by
equipment failures, human error, and faulty maintenance procedures.
Using high-efficiency washing and bleaching equipment.


35. CONCLUSION
In today's, time paper is very much essential and to meet the demand
this industry is producing huge amount of paper and causing pollution.
Though paper consumption can not be controlled but the problem arises
due this industries can be controlled by taking appropriate steps.

36. REFERENCE
Datta, Amal.K. 2013. Waste Water Treatment, Oxford & IBH Publication,
New Delhi
https://www.google.co.in/?gfe_rd=cr&ei=O3n_Vrr9Iq7v8wfC_pSQCQ&gw
s_rd=ssl#q=fluid+shear.+
http://nzic.org.nz/ChemProcesses/forestry/4C.pdf