DISSERTATION ON SUN PAPER MILL

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PAPER AND PULP PROCESSING AND ENERGY AUDIT IN SUN PAPER MILLS
OF CHERANMAHADEVI
Dissertation submitted to the
MANONMANIAM SUNDARANAR UNIVERSITY
in partial fulfilment of the requirements for the degree of
Master of Science (Integrated)
in
Environmental Science
Submitted By
M. SENTHIL KUMAR
(Reg. No. 361157)
Under the Guidance of
Dr A.G. MURUGESAN
Senior Professor and former Head
MANONMANIAM SUNDARANAR UNIVERSITY,
SRI PARAMAKALYANI CENTRE OF EXCELLENCE IN ENVIRONMENTAL
SCIENCES,
ALWARKURICHI – 627412,
TAMILNADU, INDIA.
MAY- 2019

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MANONMANIAM SUNDARANAR UNIVERSITY
Sri Paramakalyani Centre of Excellence in Environmental Sciences
Alwarkurichi-627412, Tamil Nadu, India.
Tel (O): 04634-283883
Tel (R): 04633-257657
Moblie:9443407457
agmspkce@rediffmail.com
Dr A.G.MURUGESAN, PhD., F NABS., FAZ., FAEB., FASc., AW.,.FST FAScC.,
Senior Professor
CERTIFICATE
This is to certify that this thesis entitiled “Paper and Pulp Processing and Energy Audit
in Sun Paper Mills of Cheranmahadevi” submitted by M. SENTHIL KUMAR (Reg.
No. 361157) in partial fulfilment of the award of Master of Science in Nanoscience to the Sri
Paramakalyani Centre of Excellence in Environmental Sciences, Manonmaniam Sundaranar
University, is based on the results of the studies carried by her under my supervision. Further
certified that this work has not been submitted elsewhere for any other degree.
Head of the Department Signature of Guide
Place: Alwarkurichi External examiner
Date :

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M. SENTHIL KUMAR (Reg No. 361157)
M. SENTHIL KUMAR (Reg No.361157)
M.Sc., (Environmental Science – Integrated programme),
Sri Paramakalyani Center of Excellence in Environmental Sciences,
Alwarkuruchi, Tirunelveli, Tamil-Nadu, India.
DECLARATION
I do hereby declaring that Mini-Project dissertation entitle “Paper and Pulp Processing and
Energy Audit in Sun Paper Mills of Cheranmahadevi” has been originally carried out by
me under the guidance of Dr A.G. Murugesan Senior Professor and former Head, Sri
Paramakalyani Center of Excellence in Environmental Sciences, Manonmaniam Sundaranar
University. No part of project work has been submitted for the award for any degree, diploma,
fellowship or other similar titles and that the work has not been published in any part or full in
any other Scientific Journals or Magazines.
Place: Alwarkurichi
Date:
(M. SENTHIL KUMAR)
Manonmaniam Sundaranar University
Sri Paramakalyani Centre of Excellence in Environmental Sciences
Alwarkurichi, Tamil Nadu, India- 627 412

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ACKNOWLEDGEMENT
First of all we express my profound gratitude to Almighty God for the inspiration and
guidance at all stages of this project work.
Firstly, I would like to express my sincere gratitude to my advisor Dr. G. ANNADURAI,
Professor and Head in Environmental Sciences for suggesting the topic and his constant words
of encouragement and prudent suggestions which helped me to enable this project destination.
We have unique pleasure and honor in thanking my guide Dr. A.G. Murugesan, Senior
Professor, Sri paramakalyani center of excellence in environmental sciences, Manonmaniam
Sundaranar University, Alwarkurichi, for the excellent ideas, outstanding guidance and
patient monitoring during the entire period of the project work.
My sincere thanks to other faculties Dr. S. Senthil Nathan, Dr. R. Soranam,
Dr. M. Muralidharan, Dr. M. Vanaja, Dr. M. Sivakavinesan, and Dr. T. Shibila for
providing me with all the necessary facilities for this project.
I especially thank my beloved friends J. Jenson Samraj, A. Selvaraj, P. Vishnu, P.
Malarvizhi, A. Selvaraj, A. Rajeeva Adlin, K. Ajay Kallapiran, M. Murugesh,
M. Esakki Raja, K. Vetri, and E. Mariappan, who taught me how to perform research at a
competitive level, for their continued support and guidance throughout my work to complete
my thesis.
Further, I would like to thank all Ph.D. Scholar and Non-Teaching staffs of this center,
who gave me moral support and motivation, not only as scholars also as brothers and sisters.
Words seem to be inadequate to express my deep sense of indebtedness to my beloved
parents who spend their today for our tomorrow. Without their generous, sacrifices,
motivation and inspiration, this study would not have been the light of the day.
(M. SENTHIL KUMAR)

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ABSTRACT
Pulp and paper industry in India is the fifteenth largest industry in the world. The Sun Paper
Mill was established at the year of 1964. It is a private industry situated in Cheranmahadevi.
Paper manufacturing process requires major raw materials include timbers, bamboo, rice straw,
recyclable waste papers etc.,. Paper can be manufactured by various steps include pulping,
deinking, screening, demineralization, deionization, bleaching, beating, pulp to paper and
finally the finishing process. Waste water can be released in each parts of the mill. It is the
major water polluting industry due to the contaminants present in the waste water effluent if it
is directly released into the environment can cause severe impacts. So these waste waters are
treated before it is released into the environment. The treated effluent is consumed by the
plantations present inside the industry, the treated sludge from the waste water treatment plant
is also used as a fertilizer. Some of the important parameters of untreated and treated effluents
are being checked by the industry and the data will be forwarded to CPCB and TNPCB. Air
pollution from the paper and pulp industry can be reduced by the installation of ESP, cyclones,
bag filters also the gaseous can be reduced by different methods like absorption, adsorption,
condensation and incineration.
KEYWORDS: Pulp and paper industry, CPCB, TNPCB, ESP, Treated effluent.

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TABLE OF CONTENTS
CHAPTER
NO
TITLE PAGE NO
ABSTRACT v
LIST OF TABLES vii
LIST OF FIGURES viii
LIST OF ABBREVIATIONS ix
I INTRODUCTION 1
II LITERATURE REVIEW 31
III PAPER MANUFACTURING PROCESS
3.1 PULP MAKING AT THE INDUSTRY 58
3.2 CHEMICAL PULPING 60
3.3 MECHANICAL PULPING 62
3.4 DE-INKING THE PULP 63
3.5 POIRE 64
3.6 TECHNICAL SPECIFICATION 65
3.7 HIGH DENSITY CLEANING 65
3.8 CH 7 SCREEN 66
3.9 CENTRICLEANER SYSTEM 67
4.0 DISC FILTER 67
4.1 SCREW PRESS 68
4.2 RECYCLING PROCESSES 69
4.3 DIFFERENT STAGES AFTER PULP MAKING 70
4.4 DEMINERALIZED PLANT 71
4.5 ACTIVATED CARBON FILTERS 72
CONCLUSION 75
REFERENCE 76

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LIST OF TABLE
TABLE NO TITLE PAGE NO
1.1 Power distribution in textile mill (Section wise) 37

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LIST OF FIGURES
FIGURE NO TITLE PAGE NO
1.1 Micrograph of paper autofluorescing
under ultraviolet illumination
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1.2 Schematic view of P.F.D of De-inking unit of Sun
paper mill
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1.3
Showing the arrangement of a vertical
pressure sand filter.
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1.4 Schematic view of P.F.D of
Demineralized Plant.
6
1.5 Power map of a composite mill 36
1.6 Energy savings is achieved 36

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CHAPTER I
INTRODUCTION
1.1 About the company
Paper industry in India is the 15th largest paper industry in the world. It provides
employment to nearly 1.5 million people and contributes Rs.25/- billion to the
governments kitty. The government regards the paper industry as one of the 35
high priority industries of the country.The Sun paper mill was established at the
year 1964. It is a private industry situated in Cheranmahadevi. It is one of the top
paper manufacturers in Tamil Nadu. In paper mill, pulp is mixed with Alum, talc
and dyes in a tank known as ‘beater.’ After beating pulp is refined is refined in a
machine known as ‘Jordan.’ Refined paper is then diluted for consistency and
passed through screen to remove lumps and knots. Sun Paper Mill at Trinelveli
producing 80 tonnes of paper per
day in order to meet its own requirements. The annual global paper and
paperboard production was approximately 382.0 million tones in 2006. It is
expected to increase to 402.0 million tones by 2010 and 490.0 million tones by
2020 In India pulp and paper Industry is the sixth largest consumer in the
industrial sector Main consumer of natural resources:
1. Wood (as raw material)
2.Fossil-fuel, electricity (as energy) and
3.Water
1.2 PAPER
Paper is a skinny material produced via pressing together wet fibers of cellulose
pulp derived from wooden, rags or grasses, and drying them into bendy sheets. It
is a flexible material with many uses, along with writing, printing, packaging,
cleansing, adorning, and a number of commercial and production tactics. Papers
are essential in criminal or non-criminal documentation.

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1.3 HISTORY OF PAPER
The pulp papermaking technique is said to have been evolved in China at some
point of the early second century CE, likely as early as the year one zero five CE,
by using the Han court docket eunuch Cai Lun, even though the earliest
archaeological fragments of paper derive from the 2nd century BCE in China.
The present day pulp and paper industry is international, with China leading its
manufacturing and the USA proper in the back of it. The oldest recognised
archaeological fragments of the instant precursor to trendy paper date to the
second century BCE in China. The pulp paper-making method is ascribed to Cai
Lun, a 2nd-century CE Han court eunuch.
In the thirteenth century, the understanding and makes use of of paper unfold
from China via the Middle East to medieval Europe, in which the primary water-
powered paper generators were built. Because paper turned into brought to the
West thru the metropolis of Baghdad, it become first known as bagdatikos. In the
19th century, industrialization greatly decreased the cost of producing paper. In
1844, the Canadian inventor Charles Fenerty and the German F. G. Keller
independently advanced approaches for pulping wooden fibers.

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CHAPTER II
LITERATURE REVIEW
Shen Lu et al (2012) report that energy audits have contributed significantly to
improving energy efficiency in China; energy-efficiency opportunities identified
through energy audits and implemented by enterprises reduced China’s energy
intensity by 19.1 percent during the 11th five-year plan (2006-2010).
Schleich et al (2004) reports that energy audits could help overcome several
barriers to improving energy efficiency in Germany, including providing missing
information about energy consumption patterns and energy-saving measures
Olatunde Ajani Oyelaran et al (2016) revealed that the energy audit will not only
minimize the losses but also reduce monthly electricity bill. The objective of
Energy Management is to achieve and maintain optimum energy procurement
and utilization, throughout the organization as to minimize energy costs and
wastage without affecting production and quality. Energy Audit is the key to a
systematic approach for decision-making in the area of energy management. It
attempts to balance the total energy inputs with its use, and serves to identify all
the energy streams in a facility
Aarti K (2016) Energy audit provides an important tool in reducing barriers in
energy efficiency. Industrial energy efficiency isone of the most important means
if reducing the threat of increased global warmingas the industry accounts for
80% of world’s annual coal consumption, 40% of world’selectricity use, 35% of
world’s natural gas consumption and 10% of world’s global oil consumption.

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Malkiat Singh et al (2012) claims that energy audit is essential to decrease energy
wastages and to reduce electrical billing. Energy audit concept is a measure of
the efficiency of energy utilization in a manufacturing process,
thus leading to interest in energy performance of machines and plants directly
associated with production process.
Kongara Ajay et al (2014) The efficiency of the controlled lightning design will
not only reduce power consumption but also will be an important energy saving
component. Here comparison of the power consumption between different
lightings has been done and their consumption and payback period has been
calculated respectively.
Gui-Bing Hong et al (2011) has designed an energy flow structure to show the
energy distribution to find the reasons for energy losses to achieve energy
conservation.

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CHAPTER III
PAPER MANUFACTURING PROCESS
3.1 PULP MAKING AT THE INDUSTRY
The Conveyor used sun paper industry holds about 3 tonne capacity. But, they
are using only 2.5tonne. It digest the local newspaper of about 70% and record
note paper of about 30%. This is a continuous process going on in the industry as
a product of pulp. Caustic soda is used about ½ Kg with a centrifugation of about
15 minutes and the rpm of about 1300 with the Ph 9. Dump Chest Some mills,
particularly in Asia, opt for a soak tank provides ranging from a few minutes to
several hours. Rational for this include that this provides opportunity for fibers
to "swell", or that this allows time for flakes to defiber. The manufacture of pulp
and paper is a resource-intensive industry that consumes large amounts of energy,
water, and trees The main purpose of the dump chest is to handle variations in
consistency from the pulping system. A buffer is often critical since there may
be no other large retention tanks further into the system. This again is a
cost/quality issue – a large retention time corresponds to an increase in capital
cost.
Chipped cellulose materials are digested with different chemicals in one tank
under high temperature and pressure. The process thus loosens the cellulose fibers
and dissolves the lignin, resin in the raw material. Chemicals used are- sodium
sulphate, sodium hydroxide and sodium sulphide. Spent black liquor is produced
from digestion process. This black liquor is very rich in chemicals therefore it is
separated and treated for recovery of chemicals.
Cellulosic fibers are washed and dewatered in ‘decker’ screen. Washed cellulosic
fibers are sent for bleaching in three stages where chlorine, caustic and
hypochlorite are used in successive stages. The bleached pulp is sent for paper
mill. The pulp is then passed through belt of fine screens to a series of rolls, where
the product paper is produced. The drained water is called as white water. The

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main steps in pulp and paper manufacturing are Wood yard Pulping Bleaching.
The significant environmental impacts of the manufacture of pulp and paper
result Paper manufacture from the pulping and bleaching processes.
3.2 Chemical pulping
Tomake pulp from wood, a chemical pulping process separates lignin from
cellose fibers.This is accomplished by dissolving lignin in a cooking liquor, so
that it may be washed from the cellulose; this preserves the length of the cellulose
fibres. Paper made from chemical pulps are also known as wood-free papers–not
to be confused with tree-free paper; this is because they do not contain lignin,
which deteriorates over time. The pulp can also be bleached to produce white
paper, but this consumes 5% of the fibres; chemical pulping processes are not
used to make paper made from cotton, which is already 90% cellulose.
Fig.1.1 Micrograph of paper autofluorescing under ultraviolet illumination
There are three main chemical pulping processes: the sulfite process dates back
to the 1840s and it was the dominant method extent before the second world war.
The kraft process, invented in the 1870s and first used in the 1890s, is now the
most commonly practiced strategy, one of its advantages is the chemical reaction
with lignin, that produces heat, which can be used to run a generator. Most
pulping operations using the kraft process are net contributors to the electricity

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grid or use the electricity to run an adjacent paper mill. Another advantage is that
this process recovers and reuses all inorganic chemical reagents. Soda pulping is
another specialty process used to pulp straws, bagasse and hardwoods with
high silicatecontent.
3.3 Mechanical pulping
There are two major mechanical pulps: thermomechanical pulp (TMP) and
groundwood pulp (GW). In the TMP process, wood is chipped and then fed into
steam heated refiners, where the chips are squeezed and converted to
fibresbetween two steel discs. In the groundwood process, debarked logs are fed
into grinders where they are pressed against rotating stones to be made into fibres.
Mechanical pulping does not remove the lignin, so the yield is very high, >95%,
however it causes the paper thus produced to turn yellow and become brittle over
time. Mechanical pulps have rather short fibres, thus producing weak paper.
Although large amounts of electrical energy are required to produce mechanical
pulp, it costs less than the chemical kind.
3.4 De-Inking the Pulp
In Sun paper mill the Deinking unit works on the several possible ways. Initially,
the feeding coveyor contains the waste papers which is to be deinked. Then, the
materials will pass into the Hi-con pulper of about 25 m3
. Hi-Con Pulping systems
aim to slush the raw material as completely as possible without damaging fibres
and without breaking down non-paper components. and then it passes through
poire

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3.5 Poire
The poires are made in S.S.304 , 8mm thick plate & base in M.S .The poire has
the function to keep clean a continuous pulper. The pulp from above the screen
plate of the pulper is taken into the poire . The accepts through the 12mm diameter
hole screen plate taken as feed forward. After a pre-determined time, the valve,
which draws flow from the pulper is closed , wash water is introduced in order to
recover the fibre. After this rejects are purged out through the light reject to a
drum thickener and the accept of which as usual is taken back to the pulper vat
thus ensuring zero fibre loss. Subsequently, heavy rejects are discharged from the
bottom like plastics, cloths etc.
3.6 Technical Specification
Vat Size : 1,800MM dia X 1,450MM Length
Rate Volume : 3m3
Motor Rating : 90/1440HP/rpm
Rotor Speed : 300rpm
Operating Consistency : 3.0-4.0%
Impeller dia : 1,500mm
Screen Plate Perforation : 6- 8mm (As per requirement)
Drive : V Belt
The dumping chest is about 180 m3
where the raw materials are dumped into this
chest. The constant level chest accepts the dumping chest. It persistently passes
through the high density cleaner

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3.7 High Density Cleaning
Following the Dump Chest, the stock is pumped at approximately 3.9%
consistency to two High Density Cleaners for the removal of heavy contaminants
such as nuts, bolts, stones and glass. A recirculation line from the accepts of the
High Density Cleaners returns to the Dump Chest to insure a constant flow
through the cleaners. Rejects from the High Density Cleaners are periodically
dumped to the Grit Classifier for dewatering to approximately 50% moisture.
Heavy contaminants from the Grit Classifier drop onto the Rejects Compactor
Feed Conveyor prior to dewatering in the Rejects Compactor. Effluent from the
Grit Classifier is sent to the Deink Sump. It reject Sand, pin etc.
3.8 Ch 7 Screen
It has a hole of about 1.8 mm. It reject screened by D2 screen and it is accepted
by constant level chest. It rejects the constant level box and sends to mac cell 1st
stage pump. The deink cell contains about 592 m3
/ hr and rejects to the foam tank
and finally it passes through the sludge treatment. The constant level box II
tranfers to the deaeratino chest. Then it reaches the primary centricleanrer.
3.9 Centricleaner System
Centricleaner System is secondary cleaning system which removes Sand and
other residues that results from primary cleaning, to ensure that not much pulp is
lost during the first phase. This process can be carried out up to three or four times
to achieve higher results and lower efficacy. The primary centricleanrer passes
through the secondary stage and the secondary stage transfers the pulp to the
deaeration chest and the tertiary stage. The pulp from the fourth stage will be
rejected and it is transferred into the disc filter.

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Special features of these Centricleaners include low rejection of fiber and
pressure drop. Designed and fabricated with SS 316 and 304 materials, these
cleaners have headers that are inlet tapered and the pulp valve being made in SS
Plate with construction with CI body.
It also helps in recovery of fibers during the last stage of the process and available
in 300, 500, 750 and 100 LPM throughput. With robust construction and
exclusive features the Centricleaners are among the featured machinery and
equipment for pulp and paper making industry. Precision designing is what makes
them of the highest standard.
4.0 Disc filter
The disc filter has a size of about 11/13, 3.7m in diameter. It filters out every
pulp materials and it passes through the cloudy water tank of 180 m3
capacity.
Then it passes through the pulper dilution, where it is filtered out. It also has a
network to the clarifier and the sludge and clear water tank and the shower pipe,
centricleaner and the screen dilution.
4.1 Screw Press
The pulp from the stand pipe, MC pump passes the stuffs to the screw press. The
screw press has the connection to the clarifier which has PPM of 300E and from
the clarifier it passes through the clear water tank and finally it reaches the shower
pipe, centricleaner, and screen dilution. The there are few process like plug screw,
shredder, heater mixer, infeeder, disperser, high density tower of 120 m3, transfer
tower and finally it reaches the paper machine.

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Fig. 1.2 Schematic view of P.F.D of De-inking unit of Sun paper mill.

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4.2 Recycling processes
Paper recycling processes can use either chemically or mechanically produced
pulp; by mixing it with water and applying mechanical action the hydrogen bonds
in the paper can be broken and fibres separated again. Most recycled paper
contains a proportion of virgin fibre for the sake of quality; generally speaking,
de-inked pulp is of the same quality or lower than the collected paper it was made
from.
There are three main classifications of recycled fiber:.
• Mill broke or internal mill waste – This incorporates any substandard or
grade-change paper made within the paper mill itself, which then goes back
into the manufacturing system to be re-pulped back into paper. Such out-of-
specification paper is not sold and is therefore often not classified as genuine
reclaimed recycled fibre, however most paper mills have been reusing their
own waste fibre for many years, long before recycling became popular.
• Preconsumer waste – This is offcut and processing waste, such as guillotine
trims and envelope blank waste; it is generated outside the paper mill and
could potentially go to landfill, and is a genuine recycled fibre source; it
includes de-inked preconsumer (recycled material that has been printed but
did not reach its intended end use, such as waste from printers and unsold
publications).[10]
• Postconsumer waste – This is fibre from paper that has been used for its
intended end use and includes office waste, magazine papers and newsprint.
As the vast majority of this material has been printed – either digitally or by
more conventional means such as lithography or rotogravure – it will either
be recycled as printed paper or go through a de-inking process first.

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Recycled papers can be made from 100% recycled materials or blended with
virgin pulp, although they are (generally) not as strong nor as bright as papers
made from the latter.
4.3 Different stages after Pulp making
Primary Coarse Screen Feed Chest
Accepts from the high density cleaners is discharged to the Primary Coarse
Screen Feed Chest where it is agitated and stored for about 5 minutes to produce
a leveling effect for the consistency variations coming from the High Density
Cleaners. Following the Primary Coarse Screen Feed Chest, the stock is
processed through three stages of coarse screens. The Primary Coarse Screen is
equipped with a screen basket having 0.055” holes and is fed at approximately
3.4% consistency. Accepts of the Primary Coarse Screen are directed to the
Coarse Screen Accepts Weir Box and the rejects are discharged to the agitated
Secondary Coarse Screen Feed Chest.
Secondary Coarse Screen
Rejects are diluted and pumped to the secondary coarse Screen equipped with
0.047” holes. Accepts from the Secondary Coarse Screen join the Primary Coarse
Screen accepts at the Coarse Screen Accepts Weir Box. Rejects from the
Secondary Coarse Screen are discharged under pressure to a weir box which feeds
the Tertiary Coarse Screen.
The Tertiary Coarse Screen
The Tertiary coarse screen is a gravity fed tailing screen equipped with 0.160”
holes designed to separate coarse contaminants such as plastic, polystyrene foam
and hot melt adhesives from usable fiber. The contaminants are concentrated,
rejected at atmospheric conditions onto the Rejects Compactor Feed Conveyor.
Accepted material flows by gravity back to the Secondary Coarse Screen Feed
Chest. Coarse screens with perforated (holes) screen baskets are designed to

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remove long, thin two dimensional debris that is larger than the fibers present in
the pulp slurry (in at least one dimension). Plastic, string, and wood shives are
typical examples.
Fine Screening
Accepts from the Coarse Screen. Accepts Weir Box flow to the Primary Fine
Screen Feed Chest where it is consistency adjusted and pumped to the Primary
Fine Screen. The Primary Fine Screen is equipped with a slotted basket for the
removal of small, cubical debris such as stickies and hot melts. The Primary Fine
Screen is equipped with a screen basket having 0.008” width slots and is fed at
approximately 2.8% consistency. Accepts from the Primary Fine Screen flow to
the Primary Fine Screen Accepts Weir Box. Basket of size 500 has slot width of
0.15 mm thickness; 300 has 0.15 mm thickness; 3 A basket with slot size 0.2 mm
and the debris start moving from reversal position.
Rejects from the Primary fine screen are discharged under pressure to the
Secondary Fine Screen Feed Chest. After being diluted to approximately 1.9%
consistency, stock is pumped to the Secondary Fine Screen. The Secondary Fine
screen is equipped with 0.006” width slots. Accepts from the Secondary Fine
Screen are combined with the Primary Fine Screen Accepts in the Fine Screen
Accepts Weir Box. Rejects from the Secondary Fine Screen are sent to the
Tertiary Fine Screen Feed Chest.
Secondary Fine Screen rejects are diluted in the Tertiary Fine Screen Feed Chest
and then pumped to Tertiary Fine Screen which is equipped with a 0.006” slotted
basket. Accepted stock from the Tertiary Fine Screen returns to the Primary Fine
Screen Feed Chest while the rejects are discharged to the PRF Chest.

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Flotation
Regulated flow from the fine screen accepts Weir Box is diluted to approximately
1.0% consistency and fed to four Pressurized Deinking Modules (PDMs) installed
in series. Each PDM will be fed by an individual booster pump to guarantee the
correct operating pressure is maintained for each module. Accepts from the final
PDM flows under pressure to the PDM Accepts Weir Box. Rejected material
from each deinking stage is removed under pressure and separated from the
accompanying air by an individual cyclone separator. Rejects from the cyclone
separators flow by gravity to the PDM Rejects Weir Box and onto the PRF Chest.
Flotation is used primarily for the separation and removal of ink and other small
dirt particles from the stock suspension.
4.4 DEMINERALIZED PLANT
Pressure sand filter
A typical pressure sand filter consists of a pressure vessel. This could be either
vertical or horizontal-fitted with a set of frontal pipe work and valves, graded
sand supported by layers of graded under bed consisting of pebbles and silex, a
top distributor to distribute the incoming water uniformly throughout the cross
section of the filter, and an under drain system to collect filtered water. It
maintains pH of about 7.2.
Fig. Showing the arrangement of a vertical pressure sand filter.

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Working Principle
In pressure sand filter raw water flows down wards through the filter bed and
as the suspended matter- which has usually been treated by addition of a
coagulant like alum- is retained on the sand surface and between the sand grains
immediately below the surface. There is steady rise in the loss of head as the
filtration process continues and the flow reduces once the pressure drop across
the filter is excessive.
The filter is now taken out of service and cleaning of the filter is effected by
flow reversal. To assist in cleaning the bed, the backwash operation is often
preceded by air agitation through the under drain system. The process of air
scouring agitates the sand with a scrubbing action, which loosens the
intercepted particles. The filter is now ready to be put back into service
4.5 Activated Carbon filters
These are the filters used to remove the chlorine ions present in the
wastewater. Carbon filtering is a method of filtering that uses a bed of activated
carbon to remove contaminants and impurities, using chemical absorption. Each
particle/granule of carbon provides a large surface area/pore structure, allowing
contaminants the maximum possible exposure to the active sites within the filter
media. One pound (453 g) of activated carbon contains a surface area of
approximately 100 acres (40 Hectares). Activated carbon works via a process
called adsorption, whereby pollutant molecules in the fluid to be treated are
trapped inside the pore structure of the carbon substrate. Carbon filtering is
commonly used for water purification, in air purifiers and industrial gas
processing, for example the removal of siloxanes and hydrogen sulfide from
biogas. It is also used in a number of other applications, including respirator
masks, the purification of sugarcane and in the recovery of precious metals,
especially gold. It is also used in cigarette filters. Active charcoal carbon filters
are most effective at removing chlorine, sediment, volatile organic compounds

17
(VOCs), taste and odor from water. They are not effective at removing minerals,
salts, and dissolved inorganic compounds. Typical particle sizes that can be
removed by carbon filters range from 0.5 to 50 micrometers. The particle size
will be used as part of the filter description. The efficacy of a carbon filter is also
based upon the flow rate regulation. When the water is allowed to flow through
the filter at a slower rate, the contaminants are exposed to the filter media for a
longer amount of time.
4.6 UNDERSTANDING ION-EXCHANGE RESIN IN PAPER MILL
4.6.1 Strong acid cation
Strongly acidic cation ion exchange resins are available in many size gradings
including uniform particle size. They are available with many types of regulatory
approvals such as NSF Certified, Kosher and Halal. Resins with sulfonic acids as
their functional groups, are called strongly acidic cation exchange resins, since
their acidity is strong as hydrochloric acid or sulfuric acid. DIAIONtm SK, PK,
and HPK series belong to this classification. Ion-exchange can be done using this
type of acids.
4.6.2 Degas tower
It removes dissolved gases and other contaminants for high purity water. Some
industrial applications and processes require ultra pure water with extremely low
levels of dissolved gases and other contaminants. Degasification / decarbonation
increases the life of the process equipment by preventing or controlling corrosion.
4.6.3 Degassifier tank
For a small amount of entrained gas in a drilling fluid, the degasser can play a
major role of removing small bubbles that a liquid film has enveloped and
entrapped. In order for it to be released and break out the air and gas such as
methane, H2S and CO2 from the mud to the surface, the drilling fluid must pass

18
degassing technique and it can be accomplished by the equipment called degasser
which is also a major part of a mud systems.
4.6.4 Weak base anion
Weak base anions are more chemically stable than strong base anions and are
used for the removal of mineral acids, organic acids and other organic materials.
By adding NaoH we can reduce its pH weak base anion exchange resins that are
considered leading technology for Cr removal. Three different weak base anion
exchange resins that are commonly used for treatment of groundwater pollutants
were used in the metal nanoparticle impregnation in conjunction with various
metal precursor concentrations. weak base anion exchange resin made of
phenol-formaldehyde polycondensate, had undergone an unknown
functionalization, and had 60% moisture content.
4.6.5 Strong base anion
Strong base anion resins will remove gram-negative bacteria. It contains Quarter
ammonium salts of polymers. Another possible process to create deionized water
is electrodeionization.These systems consist of two vessels - one containing a
cation-exchange resin in the hydrogen (H+) form and the other containing an
anion resin in the hydroxyl (OH-) form (see picture below). Water flows through
the cation column, whereupon all the cations are exchanged for hydrogen ions.
The decationised water then flows through the anion column. This time, all the
negatively charged ions are exchanged for hydroxide ions which then combine
with the hydrogen ions to form water (H2O). These systems remove all ions,
including silica. In the majority of cases it is advisable to reduce the flux of ions
passed to the anion exchanger by installing a CO2 removal unit between the ion
exchange vessels. This reduces the CO2 content to a few mg/l and brings about a
reduction of the following strong base anion resin volume and in the regeneration
reagent requirements. In general the strong acid cation and strong base anion resin

19
system is the simplest arrangement and a deionized water that may be used in a
wide variety of applications can be obtained with it.
4.6.6 Weak-Acid Cation Exchanger
These are polymers contains carboxylic acid group. Ion-exchange resin
capable of exchanging hydrogen ions for only the cations of the salts of weak
acids. For example, the resin will exchange the hydrogen (H+) ion for the calcium
(Ca++) in calcium bicarbonate [Ca(HCO3)2]. but not for the Ca++ calcium
chloride (CaCl2). The acid strength of the exchanger is similar to that of acetic
acid. Weak-acid cation exchangers are commonly called carboxylic resins.
4.6.7 Weak-Base Anion Exchanger
These are polymers contains 1°,2° and 3° amine group. Ion-exchange resin
capable of removing strong acids such as hydrochloric (HCl), sulfuric (H2S04),
and nitric (HNO3). True weak-base resins will not adsorb weak acids such as
carbonic (H2C03) and silicic (H2SiO3). When regenerated with caustic, weak-
base resins are converted to the free-base form with a base strength similar to
ammonia. When operated in the freebase form, the entire acid molecule is
adsorbed.
4.6.8 Mixed bed
Mixed bed resins or mixed bed ion exchange resins are mainly used in the water
purification industry for polishing process water to achieve demineralized water
quality (such as after a reverse osmosis system). Mixed bed as the name states
consists of strong acid cation exchange and strong base anion exchange resin.
Typical applications include:
(i) Ultra pure water production
(ii) Demineralisation

20
(iii)Condensate polishing (boiler feed water)
(iv)Micro-electronics cleaning
(v) Pharmaceuticals
Demineralized water storage tank
Demineralised water is a water from which all minerals have been removed.
Demineralised water is generally acidic (carbonic acid due to the CO2 in the air
in contact with the liquid) and it tends naturally to produce a leaching
phenomenon of the materials with which it is in contact. Many demineralized
water storage tanks are dosed with ammonia and hydrazine to reduce the
oxygen content. These mitigation practices, however, increase by about 10
times the concentration of carbonate due to the formation of ammonium
carbonate. It is used as a boiler in paper industry.
Dual media filter
This Filter is designed for removal of Turbidity & Iron. Maximum Iron as Fe –
1.0 PPM Maximum Turbidity – 25 PPM. For effective removal Oxidation
Chamber & Coagulant addition, pH Correction, aeration have o employed prior
to filtration. Pressure sand filter has limited dirt removal as the finest sand from
the top most layer and as much most layer and as such most of the Turbidity is
deposited on the top surface resulting in cake formation In Case of Dual Media
Filter a 300 mm layer of coarse anthracite is provided on top of fine sand. The
advantage of providing anthracite layer is 1. The coarse anthracite does pre
filtration and removes most of turbidity from water before the water comes in
contact with fine sand 2. The coarse anthracite is provided for holding higher
amount of turbidity within the bed. The anthracite being coarse provided less
pressure drop. Maximum Service velocity: 15 mtr/hr Backwash: 15 mtr/hr Air
Scoring : 36 mtr/hr.

21
Cooling towers
Cooling towers are a very important part of many chemical plants. The primary
task of a cooling tower is to reject heat into the atmosphere. They represent a
relatively inexpensive and dependable means of removing low-grade heat from
cooling water. The make-up water source is used to replenish water lost to
evaporation. Hot water from heat exchangers is sent to the cooling tower. The
water exits the cooling tower and is sent back to the exchangers or to other units
for further cooling.

22
Fig.1.4 Schematic view of P.F.D of Demineralized Plant.

23
4.7 CO-GENERATION PLANT
Cogeneration or combined heat and power (CHP) is the use of a heat engine
or power station to generate electricity and useful heat at the same time.
Trigeneration or combined cooling, heat and power (CCHP) refers to the
simultaneous generation of electricity and useful heating and cooling from the
combustion of a fuel or a solar heat collector. The terms cogeneration and
trigeneration can be also applied to the power systems generating simultaneously
electricity, heat, and industrial chemicals – e.g., syngas or pure hydrogen (article:
combined cycles, chapter: natural gas integrated power & syngas (hydrogen)
generation cycle).
Cogeneration is a more efficient use of fuel because otherwise wasted heat
from electricity generation is put to some productive use. Combined heat and
power (CHP) plants recover otherwise wasted thermal energy for heating. This is
also called combined heat and power district heating. Small CHP plants are an
example of decentralized energy. By-product heat at moderate temperatures
(100–180 °C, 212–356 °F) can also be used in absorption refrigerators for
cooling.
The supply of high-temperature heat first drives a gas or steam turbine-
powered generator. The resulting low-temperature waste heat is then used for
water or space heating. At smaller scales (typically below 1 MW) a gas engine or
diesel engine may be used. Trigeneration differs from cogeneration in that the
waste heat is used for both heating and cooling, typically in an absorption
refrigerator. Combined cooling, heat and power systems can attain higher overall
efficiencies than cogeneration or traditional power plants. In the United States,
the application of trigeneration in buildings is called building cooling, heating
and power. Heating and cooling output may operate concurrently or alternately
depending on need and system construction.
Cogeneration was practiced in some of the earliest installations of electrical
generation. Before central stations distributed power, industries generating their

24
own power used exhaust steam for process heating. Large office and apartment
buildings, hotels and stores commonly generated their own power and used waste
steam for building heat. Due to the high cost of early purchased power, these CHP
operations continued for many years after utility electricity became available.
4.8 ENERGY AUDITING
An energy audit is an inspection, survey and analysis of energy flows, for energy
conservation in a building, process or system to reduce the amount of energy input
into the system without negatively affecting the outputs. In commercial and
industrial real estate, an energy audit is the first step in identifying opportunities
to reduce energy expense and carbon footprints.
An energy audit is a fundamental first step toward reducing utility bills in a big
way. comprehensive energy audit will identify the most effective home energy
improvements that will:
a) Increase energy efficiency
b) Reduce energy usage
c) Improve indoor air quality
d) Produce consistent interior temperatures
e) Reduce interior drafts
f) Improve humidity control & ventilation
The Energy auditing is being carried out regularly by the reputed companies due
to recommendation in the Sun paper mill to reduce the energy load. In this aspect,
several high value motors is being produced with the A/C devices standard
arrangements. Routine maintainance of electrical companies and stored motors
are taken into periodic maintanance schedules. Wherever the pump is removing,
the suitable low size motors and the corresponding resized pump is fixed to

25
minimize the power consumption. Most of the office street lights are replacing
the LED lights.
An energy audit is a primary step toward improving energy efficiency at the
facility level. ENERGY AUDIT
4.9 ENERGY CONSERVATION IN PAPER AND PULP INDUSTRY
The pulp and paper sector is a significant energy user and currently ranks
fourth in the industrial sector for its energy use. In 2006, the sector consumed 6.7
EJ of energy, which represents 6% of global industrial energy use. Despite high
energy use, the sector has a low CO2 intensity due to extensive use of biomass as
fuel (in 2006, the emissions of the sector reached 184 Mt, representing only 3%
of global emissions in 2006).1
The total energy saving potential in the sector
through improved process efficiency and systems/life cycle improvements has
been estimated to be in the range of 2.1-2.4 EJ/year.
The processes used to produce pulp and to dry paper are the major energy
consumers in the industry. The main production facilities are either pulp mills or
integrated paper and pulp mills. Integrated mills have better energy efficiency.
Kraft pulping is the most extensively used chemical pulping process. It
produces high-quality fibers for higher paper grades. However, it requires large
amounts of heat energy and has a low fiber yield. Kraft mills are able to meet
most or all of their energy needs from by-products (i.e. black liquor) and they can
even be a net exporter of energy. Similarly, sulfite pulping, which is used for
speciality papers, has a high energy consumption but can self-generate a large
part of a mill's energy needs from by-products.
Mechanical pulping produces weaker fibers but it has a high yield, giving it a
lower specific final energy demand. Higher efficiencies are enabled by
applications such as thermo-mechanical pulping, where heat is recovered at

26
diffent grades. However, as electricity is the main energy used, this technology
may have high primary energy demand and CO2 emissions.
Pulp production from recovered fibers requires substantially less energy
compared to virgin pulp (the BAT values for recovered fiber is 0.7-3 GJ/t
compared to around 14.3 GJ/t for Kraft pulping).1
It is a promising option for
reducing energy consumption and CO2 emissions, with estimates projected to be
as high as 35%. However, the availability of recovered paper is sometimes limited
and resolving this issue will require changes to other parts of the paper production
lifecycle.
The amount of energy used by paper machines is generally dependent on the
pulp quality and paper grade, and it can show big variations. Integrated mills can
achieve higher energy efficiency by eliminating intermediate pulp drying and
using better processes.
Application of Combined Heat and Power (CHP) can significantly enhance
the energy efficiency of pulp and paper industry. The CHP potential in the paper
and pulp industry is estimated to be in the range of 0.3-0.6 EJ/year. Typically, the
introduction of CHP can result in fuel savings of about 10-20% and energy
savings of 30% compared to traditional technologies.
The IEA believes black-liquor gasification and bio-refinery concepts,
advanced paper-drying techniques, increased paper recycling, and carbon capture
and storage will play a key role in reducing energy consumption and GHG
emissions in industry.
5.0 Concept of energy audit
Energy audits may be considered as the first step towards understanding how
energy is being used in a given facility. Energy audit is usually one of the
first steps in an energy management program. It shows how efficiently
energy is being used and highlights opportunities for energy cost savings. It

27
can also show ways to improve productivity. Energy audits take a thorough look
at particular facilities, processes, or technologies.
Energy audit means accounting precisely for energy purchases and energy
uses, for the various functions and processes carried out in an organization. Such
an audit is carried out in conjunction with an overall energy efficiency program
and bearing in mind the fundamental links between energy use and environmental
pollution.
An initial energy audit need not be very sophisticated or accurate. The aim
should be to obtain an overall picture of energy use and to be able to draw up an
approximate energy balance for the organization. If appropriate, further
desegregation of energy use can proceed once the initial audit has been carried
out, leading to a full-scale energy analysis. An energy audit is particularly
concerned with the question “can energy be used more efficiently to prevent
waste?” It then proceeds to identify where improvements can be made and what
those improvements are (Barratt, 1996, p. 617).
The energy audit is one of the first tasks to be performed in the
accomplishment of an effective energy cost control program. An energy audit
consists of a detailed examination of how a facility uses energy, what the facility
pays for that energy and finally recommended program for changes in operating
practices or energy-consuming equipment that will cost- effectively save on
energy bills. The energy audit is sometimes called an energy survey or an energy
analysis (Capehart et al, 2007, p. 23).
Energy audits and the ensuing cost and energy saving opportunities identified
in audits are best implemented in the context of an energy management program
that operates, and isformally recognized, as an integral part of the ongoing
management activities of the entity for which it applies. For this reason, one

28
important function of an energy audit is to evaluate the energy management
program and suggest ways in which it could be improved.
As per EECA (2007) energy audit should provide much of the essential
information to progress an energy management program and action. It should
summaries key energy use and cost indices, provide a breakdown of where
energy is used, and give a table of recommended actions. An energy audit
will also assist with preparing an action plan.
The energy audit aspects of the energy management process include
determining the level of detail (high, mid-range and detailed) that an energy
auditor will appraise when an audit is carried out, as well as the extent of any
recommendations arising from the audit process. Table shows the outcomes of
each level of detail of energy audits (Levels 1, 2 and 3 identified in the Energy
Audit Standard, EEA, New Zealand) and the differences that distinguish
between these levels.
5.1 Energy audit: Types and Methodology
Energy Audit is the key to a systematic approach for decision-making in the area
of energy management. It attempts to balance the total energy inputs with its use,
and serves to identify all the energy streams in a facility. It quantifies energy
usage according to its discrete functions. Industrial energy audit is an effective
tool in defining and pursuing comprehensive energy management program.
As per the Energy Conservation Act, 2001, India, energy audit is defined as “the
verification, monitoring, and analysis of use of energy including submission of
technical report containing recommendations for improving energy efficiency
with cost benefit analysis and an action plan to reduce energy consumption”.
5.2 Need for Energy audit

29
In any industry, the three top operating expenses are often found to be energy
(both electrical and thermal), labor and materials. If one were to relate to the
manageability of the cost or potential cost savings in each of the above
components, energy would invariably emerge as a top ranker, and thus energy
management function constitutes a strategic area for cost reduction. Energy
audit will help to understand more about the ways energy and fuel are used in any
industry, and help in identifying the areas where waste can occur and where scope
for improvement exists.
The energy audit would give a positive orientation to the energy cost
reduction, preventive maintenance and quality control programs which are
vital for production and utility activities. Such an audit program will help to
keep focus on variations, which occur in the energy costs, availability, and
reliability of supply of energy, decide on appropriate energy mix, identify energy
conservation technologies, retrofit for energy conservation equipment etc. In
general, Energy audit is the translation of conservation ideas into realities, by
lending technically feasible solutions with economic and other organizational
considerations within a specified period. The primary objective of energy audit is
to determine ways to reduce energy consumption per unit of product output or to
lower operating costs. Energy audit provides a “bench-mark” for managing
energy in the organization and provides the basis for planning a more effective
use of energy throughout the organization.
5.3 Type of Energy audit
The type of energy audit to be performed depends on:
1. function and type of industry,
2. depth to which final audit is needed, and
3. potential and magnitude of cost reduction desired.
4. Thus, energy audit can be classified into the following two types:

30
5. preliminary audit,
6. detailed audit.
5.4 Preliminary energy audit Methodology
Preliminary energy audit is a relatively quick exercise to:
(i) establish energy consumption in the organization
(ii) estimate the scope for saving
(iii)identify the most likely (and the easiest areas for attention
(iv)identify immediate (especially no-/low-cost) improvements/ savings
(v) set a ‘reference point’
(vi)identify areas for more detailed study/measurement
(vii) preliminary energy audit uses existing, or easily obtained data.
5.5 Detailed energy audit Methodology
A comprehensive audit provides a detailed energy project implementation
plan for a facility, since it evaluates all major energy using systems. This type of
audit offers the most accurate estimate of energy savings and cost. It considers
the interactive effects of all projects, accounts for the energy use of all major
equipment, and includes detailed energy cost saving calculations and project cost.
In a comprehensive audit, one of the key elements is the energy balance. This
is based on an inventory of energy using systems, assumptions of current
operating conditions and calculations of energy use. This estimated use is
then compared to utility bill charges. Detailed energy auditing is carried out
in three phases:
(i) phase I - pre audit phase
(ii) phase II - audit phase
(iii)phase III - post audit phase.

31
While every industrial facility is different, there are several energy efficiency
opportunities, which typically provide high returns. Typical energy efficiency
opportunities are: steam system upgrades; heat recovery; compressed air system
upgrades; lighting; motor and drive system upgrades; energy efficiency in
buildings; production of energy from waste; cogeneration; modernization;
water system upgrades and re-use etc.
Technical and economic feasibility: After identification of energy
conservation opportunities, both technical and economic feasibility are to be
established. The technical feasibility depends on technology availability, space,
skilled work force, reliability, service etc; the impact of energy efficiency
measure on safety, quality, production, or process; the maintenance
requirement and spares availability.
Acceptance of energy conservation opportunities by the management
depends on the economic viability and often it becomes the key parameter. The
economic analysis can be conducted by using a variety of methods. Example: Pay
back method, internal rate of return method, net present value method etc. For
low investment short duration measures, which have attractive economic
viability, simplest of the methods, payback is usually sufficient.
Classification of energy conservation measures: Based on energy audit and
analyses of the plant, a number of potential energy saving projects may be
identified. These may be classified into three categories:
(i) Low cost –high return;
(ii) Medium cost- medium return;
(iii)High cost –high return.
Normally low cost- high return projects receive priority. Other project have to
be analyzed, engineered, and budgeted for implementation in phase manner.
Projects relating to energy cascading and processes changes usually involve high

32
cost coupled with high return, and may require useful scrutiny before fund can be
committed. These projects are generally complex and may require long lead
times before they can be implemented.
5.6 Benchmarking and Energy performance
A successful program in energy management begins with a strong
commitment to continuous improvement of energy efficiency. As a first step,
once the organizational structure has been established is to assess the major
energy uses in the facility to develop a baseline of energy use and set goals for
improvement. The selection of key performance indicators and goalshelp to shape
the development and implementation of an action plan. An important aspect for
ensuring the successes of the action plan is involving personnel throughout the
organization. Personnel at all levels should be aware of energy use and goals for
efficiency. Staff needs to be trained in both skills and general approaches to
energy efficiency in day-to-day practices. In addition, performance results should
be regularly evaluated and communicated to all personnel, recognizing high
achievement. The use of energy monitoring and process control systems can play
an important role in energy management and in reducing energy use. These may
include sub-metering, monitoring, and control systems. They can reduce the
time required to perform complex tasks, often improve product and data quality
and consistency, and optimize process operations (Worrell et al, 2004).
Energy benchmarking involves the development of quantitative and
qualitative indicators through the collection and analysis of energy-related data
and energy management practices. Benchmarking in simplistic terms is the
process of comparing the performance of a given process with that of the best
possible process and tries to improve the standard of the process to improve
quality of the system, product, services (Price et al., 2008) etc. It allows
organizations to develop plans on how to adopt such best practices, usually with
the aim of increasing some aspects of performance. Benchmarking may be a one-

33
off event, but is often treated as a continuous process in which organizations
continually seek to challenge their practices. Benchmarking is a method, which
should be used on a continual basis as best practices are always evolving.
The Lawrence Berkeley National Laboratory has developed an excel-based
spreadsheet tool called BEST: Benchmarking and energy saving tool for use by
industry to benchmark a plant’s energy intensity to “best practice” and to identify
energy efficiency improvement options (Price et al., 2003; Galitsky et al., 2005).
Benchmarking of energy consumption internally (historical / trend analysis)
and externally (across similar industries) are two powerful tools for performance
assessment and logical evolution of avenues for improvement. Historical data
well documented helps to bring out energy consumption and cost trends monthly,
daily. Trend analysis of energy consumption, cost, relevant production features,
specific energy consumption, help to understand effects of capacity utilization on
energy use efficiency and costs on a broader scale.
External benchmarking relates to inter-unit comparison across a group of
similar units. However, it would be important to ascertain similarities, as
otherwise findings can be grossly misleading. Few comparative factors, which
need to be looked into while benchmarking externally are (BEE, 2004):
(i) scale of operation
(ii) vintage of technology
(iii)raw material specifications and quality
(iv)product specifications and quality.
An energy audit of the mill found that the mill’s boiler control system did not
provide continuous monitoring or control of combustion air. The audit team
recommended that the mill install a control system to measure, monitor, and
control oxygen and carbon monoxide levels on it coal-fired boilers, given that
these boilers operated near full capacity and would reap the greatest benefits of

34
improved control. This measure was estimated to save nearly $475,000 in annual
energy costs; at an investment cost of $200,000, the payback period was less than
six months.A plant-wide energy audit of Georgia-Pacific’s mill in Crossett,
Arkansas, recommended improving blow heat recovery from the mill’s two
parallel batch digester lines. At the time of the audit, a cooling tower was used to
remove excess heat from the blow steam accumulator and a steam heater was
used to generate hot water for the bleach plant. The audit team recommended
installing new heat exchangers and rerouting water lines such that the cooling
tower and steam heater could be shut down. It was estimated that this project
would save 940,000 MMBtu of fuel, 705,000 MMBtu of natural
gas, and $2,350,000 in costs each year with a payback period of around one year
At the Weyerhaeuser pulp and paper mill in Longview, Washington, the proposed
addition of a digester heat recovery system was expected to result in annual
natural gas savings of 130,000 MMBtu, leading to $280,000 per year in cost
savings.Prior to application, an energy audit must be performed; however, this is
an expense that may be added to total project cost for financing.Textile industries
use energy both in the utilities and process. Electrical energy is also used in these
areas. Energy audit provides the scope of energy savings in different utilities and
process of textile industries. Electric motors contribute to more than 70% of the
total electrical load. Three phase induction motor is prominently used in the
textile industry because of its ruggedness and versatility. Loss of motor efficiency
with operation and time is a very common problem in textile industry. This paper
deals with scope of energy savings by energy audit analysis in textile industries.
A case study is also included for comparison of efficiency of old motor with
energy efficient motor. This study would be useful in finding the areas where the
energy can be saved in textile industries, scope for saving of energy, cost, CO2
emission by replacing the old rewound/ faulty motors with energy efficient
motors.

35
5.7 Matching energy usage to requirement
Mismatch between equipment capacity and user requirement often leads to
inefficiencies due to part load operations, wastages etc. Worst case design, is a
designer’s characteristic, while optimization is the energy manager’s mandate
and many situations present themselves towards an exercise involving graceful
matching of energy equipment capacity to end-use needs. Some examples of
matching energy usage to requirement are as follows:
(i) eliminate throttling of a pump by impeller trimming, resizing pump,
installing variable speed drives
(ii) eliminate damper operations in fans by impeller trimming, installing
variable speed drives, pulley diameter modification for belt drives, fan
resizing for better efficiency
(iii)moderation of chilled water temperature for process chilling needs
(iv)recovery of energy lost in control valve pressure drops by back
pressure/turbine adoption
(v) adoption of task lighting in place of less effective area lighting.
5.8 Problem Definition
During the energy audit visit investigators find that the consumption of electricity
in textile sector is increasing. It is due to the use oflarge number of electrical
equipments in textile sector. The energy cost and production cost is around 15%
to 20 % and this comes second to raw material. So investigators primefocus area
now is energy consumption at load end and by optimizing the energy usage of
textile

36
Figure 1.5 Power map of a composite mill
5.9 Energy savings is achieved
In this chapter, Figure 3 shows the methodology, which is adopted for
achieving the desired energy savings by energy audit process.
Methodology includes the discussions with the plant officials to identify the
areas for energy conservations. Energy audit team visits the site, and collects data
of operations and distribution of load within the plant. This collected data is then
analyzed and a base line is identified to get best possible energy conservation
opportunity.
Spinning
41%
Weaving
18%
Humidificatio
n…
Wet-
processing
10%
Lighting
4%
Others
8%

37
To identify the pattern of energy use and losses in the system, continuous or
time lapse recording is done by appropriate and calibrated energy audit
instruments. Actual methodology of energy auditing is presented in Figure 2.
6.0 OBSERVATIONS
Energy audit was done in one of the leadingtextile mill. The mill is located in
Himachal Pradesh. Energy audit team collected data of installed power of the
mill; which is plotted in Table 1 (department wise). By the help of Table 1, figure
2 is drawn and that area hasrecognized where major part of power is being used
and energy can be conserved.From the collected data it was found that the major
powers saving regions are replacing old ring frame motors with newer energy
efficient motors,optimize the size of ring frame suction tubes, improve the power
factor from 0.98 to 0.995 and above, replace the broken suction tube cap of
autoconer and using smaller diameter caps, replace the existing fluorescent tube
lights with LED lights, install a separate lighting feeder and install voltage
stabilizer, prevent the power loss occurring due to heavy compressed air leakages,
install VFD on supply air fan of humidification towers, replace the existing
aluminum impeller with FRP of pneumatic fans, replace existing pumps with
energy efficient pumps
Table1 Power distribution in textile mill (Section wise)
Description Installed, kW Total load , %
Blow room 57.78 2.39
Carding 328.60 13.32
Draw frame 609.00 2.48
Comber 60.23 2.41
Speed frame 67.32 2.78

38
Ring frame 1,159.88 47.12
Autoconer 195.35 7.98
Winder 27.40 1.07
Humidification Plant 285.30 11.56
Waste collection 46.48 1.85
Buffing 7.50 0.28
Compressor 92.50 3.78
Lighting 34.15 1.43
Sewage Plant 8.25 0.29
Water Pump 19.70 0.76
Admin Office 10.84 0.48
Total power 1,459.28 100
6.1 Case Study: Replacement of old motor with new energy efficient motor:
During the energy audit visit, it has been found that the plant is using 30kW,
92% efficiency IE2 motors in ring frame machines[5]. Plant management is
planning to replace the existing motors with energy efficient Opti-Power motors
(30 kW, 94% efficiency).
Flow chart for comparing two motors is as follows

39
In this article, case study depicts that there is a large scope of energy savings
in textile mills and by energy audit in regular intervals; users can find the areas
where the energy can be saved. Also by replacing the old rewound/ faulty
motors by energy efficient motors, there is scope for saving of energy, cost, CO2
emission with less payback time.
Energy Audit The auditing activities include, Identification of all energy
systems, Evaluation of conditions of the systems, Analysis of impact of
improvement to those systems and Preparation of energy audit report. The
cost/economic analysis is to be done after the audit work. The economic analysis
provides the potential savings through audit in terms of cost. On the basis of audit
results the essential steps can be taken in terms of quality control, cost effective
maintenance etc. to improve production, safety andeconomic utility activities
(Singh et al, 2012).The following types of energy audit systems are used in
industry (Alajmi A. 2012; Dall’O’ et al, 2012):
Energy audit provides the scope of energy savings in different utilities and
process of textile industries. Electric motors contribute to more than 70% of the
total electrical load. Three phase induction motor is prominently used in the
textile industry because of its ruggedness and versatility. Loss of motor efficiency
with operation and time is a very common problem in textile industry. This paper
deals with scope of energy savings by energy audit analysis in textile industries.
A case study is also included for comparison of efficiency of old motor with
energy efficient motor. This study would be useful in finding the areas where the
energy can be saved in textile industries, scope for saving of
energy, cost, CO 2 emission by replacing the old rewound/ faulty motors with
energy efficient motors.

40
1.2. Audited sections in paper industry: present case study
Pumps: Pumps are the most important rotating equipment for the transfer of
water, Pulp, Chemicals, effluent etc. in paper industry. Now by the use of this
type of audit .There exists a good scope to improve the pump efficiency and
consequently reducing energy cost
Barometric leg of Washers:
It is a multi-stage rotary vacuum washer system containing number of units
working in series. Each unit of the vacuum washer consists of a wire cloth
covering cylinder that rotates in a vat containing the pulp slurry. Vacuum is
applied from the inside of the cylinder and a pulp mat is formed on the surface of
the cylinder when in the vat. The wash water and the pulp flow in the opposite
directions which are known as concurrent washing. By the above auditing
techniques, it was suggested to remove the two vacuum pumps.
Agitator:

41
During the audit it was observed that some of the agitators in the stock preparation
were being run continuously during paper machine shutdown and it is
recommended to provide inter lock with the transfer pumps to optimize power
consumption.
Dryer head of steam Cylinders:
It was observed that dryer head of steam cylinders of both paper machine and
pulp sheeting machine were not insulated thereby increasing heat loss from the
dryer heads. It is recommended to insulate the dryer cylinders exposed to working
area to avoid convection losses.
Coal fired boilers:
During the survey it was observed that due to salts present in the water, the scaling
of the boiler surface leads to 1mm thick scale on the water side of the boiler
resulting in the Downtime reduction, Costly demineralised water was saved, by
replacing manual blow down valve with TDS blow down valve. The observed
data for the audited section
6.2 POLLUTIONS FROM THE INDUSTRY
Water pollution
In this part, recycle, reuse methods are welcomed. This mill has reactive clarifier
to recover the pulp. The parameters like BOD, COD, TSS, fluoride are being
checked by the industry and the data will be forwarded to the CPCB (Central
pollution control board) and the TNPCB (Tamil Nadu pollution control board)
The finally treated effluent is utilized only for the station. The pulp and paper
industry reduces clear cutting, water use, greenhouse gas emissions, fossil fuel
consumption and clean up its impacts on local water supplies and air
pollution.Pulp and paper mills contribute to air, water and land pollution and
discarded paper and paperboard make up roughly 26% of solid municipal solid

42
waste in landfill sites.Pulp and paper generates the third largest amount of
industrial air, water, and land emissions in Canada and the sixth largest in the
United States. The pulp and paper industry uses more water to produce a ton of
product than any other industry.The de-inking process during paper recycling is
also a source of emissions due to chemicals released in the effluent. The European
Recovered Paper Council has developed the ‘deinkability scorecard’ so that the
printed paper products which have the best recyclability when they are deinked
can be identified.
Air pollution
In pulp and paper industry air pollution is caused due to odour emitting reduced
sulphur compounds such as hydrogen sulphide, methylmercaptan,
dimethlysulphide, and particulate matter SO2 and NOx present in the gases
emitted by different process units. Gaseous emission from pulp and paper mills
can be broadly classified into the following categories:
• Gases from digesters.
• Gases from multiple effect evaporators.
• Gases from recovery.
Paper and cardboard businesses can emit dust, smoke, fumes and gases which
affect air quality. Emissions to air include:
• oxides of nitrogen (NOx), sulphur (SOx) and carbon (COx) from
combustion plant or liquor burning
• particulates and dust from combustion or paper handling
• formaldehydes and ammonia from wet strength resins
• solvents from cleaning or coating processes
• chloroform from the use of chlorine compounds in bleaching

43
• odorous substances from wet pulping or effluent treatment plants
6.3 EFFLUENT TREATMENT PLANT
ETP (Effluent Treatment Plant) is a process design for treating the industrial
waste water for its reuse or safe disposal to the environment.
• Influent : Untreated industrial waste water.
• Effluent : Treated industrial waste water.
• Sludge : Solid part separated from waste water by ETP.
Solid Waste Management in Pulp and Paper Industry
World paper industry assumes nearly 3.5% of the world industrial production and
2% of world’s trade. Demand of paper and boards worldwide will reach 470
million tonnes in 2010 with an average annual increase of paper demand of about
3.7%. Paper and boards demand is es-timated to reach 640 million tonnes in 2020.
The wood consumption in the world is expected to increase from 861 million
tonnes in 1995 to 1777 million tonnes in 2020. With merely 17 units in 1950 with
production of 0.11 million tonnes paper, presently we have about 380 mills with
a total installed capacity of around 4.2 million tonnes.
There are 28 large mills and the remaining are small paper mills. Per capita
consumption of paper in India is a meagre 3.2 kg against Asia and world average
of 18 kg and 47.7 kg respectively. Per capita consumption of paper in different
parts of world is given in Fig. 1. Projected demand of paper board in India. Per
capita consumption of newsprint is 0.6 kg as compared to Asian average of 1.9
kg and world average of 6 kg. Per capita consumption is expected to grow to 0.8
kg by 2010 AD. The demand of paper and board is estimated to be around 54.80
kg lakh tonnes by 2005-06.

44
Major raw materials used by paper industry is bamboo, wood, bagasse, waste
paper and agricultural residue like wheat straw, rice straw, jute sticks etc. Apart
from this, paper industry consumes large amount of chemicals like caustic soda,
sodium sulphide, sodium carbonate, chlorine, hypochlorite, mineral acid; coal,
talcum powder etc. Process technology used is craft pulping, mechanical pulping,
semi chemical pulping. Bleaching sequences used are CEH and CEHH in
majority of mills while chlorine dioxide bleaching and oxygen delignification is
used by very few mills.
Acute shortage and high cost of wood based raw materials has been the most
important factor restricting the growth of Indian paper industry and its
development into a globally competi-tive industry. Expert Group Committee
constituted by paper industry indicates that short fall in supply of indigenous fibre
based on projected demand and possible production may be much larger.
Agricultural residues like rice straw, wheat straw and bagasse are the promising
raw materials for paper industry. Availability of bagasse and straw are estimated
to be 2.5 million tonnes and 30 million tonnes respectively, India ranks second in
world in utilisation of non-wood fibres.
6.4 SOLID WASTE GENERATION IN PULP AND PAPER INDUSTRY
Solid waste arises at different stages of pulp and manufacture and paper
application stages. The types of solid waste and their quantities varies from plant
to plant depending on the raw material consumed, in-plant plant control measures,
external control measures, house-keeping, waste utilisation, collection and
recycling practices.
Solid waste generation can be dealt separately as solid wastes generated due to
off plant operation, in-plant plant operation and application generated.
Various solid waste generated due to off plant activities are generation of leaves,
bark, unused branches of trees, during forest operation, generation of solid waste

45
during mining of coal, lime stone which are being used in large quantities in paper
industry.
Solid waste generated at various stages of pulp and paper making during in
plant operations are:
1. Dirt, sand and other impurities from bamboo washing.
2. Bamboo and wood dust in chipper house.
3. Pith from bagasse pulping plant.
4. Knotter, screen and centric leaner rejects in pulp mill.
5. Lime dust from lime handling and slaker.
6. Grit, dregs, lime sludge in recovery section.
7. Particulate matter from recovery furnace, dissolving tank, lime kiln.
8. Centric leaner rejects from paper machines.
9. Contaminated material from waste paper plant.
10. Sludge from effluent treatment plant.
11. Sludge from raw water clarifier.
12. Boiler bottom ash and fly ash from power generation plant.
6.5 WATER REUSE
Growing water scarcity and heightened awareness associated with water
conservation are prompting more industrial manufacturers to explore water
recycling within facilities - a strategy which also reduces wastewater effluent
volumes.

46
Water recycling is an attractive proposition for industries such as P&P that
withdraw large volumes of water or have highly polluted waste streams and are
subject to increasing charges for disposal, according to a market report by
independent research and advisory firm Lux Research, which evaluated water
usage and industrial water treatment across six of the top water users among
manufacturing industries.
In Demystifying the Industrial Water Market, Lux Research found that recycling
of water within the P&P industry is an increasingly common solution because it
allows facilities to reuse water and also recover excess pulp fibers that have
escaped in the wastewater, providing the industry with a high economic incentive
to recycle its waste streams.
"Membrane technologies such as microfiltration, ultrafiltration, and
nanofiltration are the most effective strategies for treating water to a level where
it can be utilized in the beginning of a process," said Brent Giles, a senior analyst
at Lux Research.
6.6 SLUDGE MANAGEMENT
As is the case with other industrial manufacturing processes, including
wastewater treatment operations on the municipal side, residual sludge
management presents a number of challenges to the P&P industry and represents
a significant portion of a facility's total wastewater treatment costs.
Composed mainly of boiler and furnace ash, scrubber sludge, lime mud, wood
processing residuals, and various effluent solids, sludge is the largest volume
waste stream generated by the industry, making sludge handling a very important
issue, according to Meliton.
"Many of the conventional, or 'old school' P&P manufacturers continue to
employ traditional sludge management techniques that have been in place for
many years and generally include sludge disposal methods such as incineration

47
or land-filling," Meliton said. "But at the same time, it's important to realize that
P&P sludge, with further treatment, has the potential to qualify as a biosolid,
which can be used for a number of innovative solutions."
P&P mills can implement advanced technologies that convert waste sludge
into fertilizer and biogas, offering a beneficial use of a waste stream and
significantly reducing a facility's waste disposal burden.
"Manufacturers that are already meeting compliance requirements can elect to
continue to pay the tipping fees and disposal costs associated with sludge waste
disposal or they can make the necessary capital investments towards waste to
energy applications that generate renewable energy and create fertilizer, offering
a revenue incentive," Meliton said. "The decision is mainly based on whether or
not the technology justifies the capital expenses in terms of a potential return on
investment."
Some mills employing an alkaline-based manufacturing process can pursue
beneficial use projects specifically because of the calcium carbonate present in
their wastewater residuals, Garber said.
"Many paper mill wastewater residuals will have a high agricultural lime
value. Depending on the region, the land type, and if the soils are particularly
acidic, residuals with high lime content can be effective as a land application
product," he said.
6.7 ANAEROBIC DIGESTER PROCESSES
While cogeneration of biogas from wastewater anaerobic digester processes for
generating electricity and steam is an economical, long-term solution that is
increasingly being pursued in the municipal sector, this approach has been
relatively slow to gain traction in the P&P industry, mainly because of the high
capital costs associated with implementation.

48
"Anaerobic digester processes are rarely used in the P&P industry," Garber said.
"More frequently, energy recovery initiatives are based on taking dewatered
solids produced from primary or secondary clarification and burning the material
in wood-fired boilers for the production of steam, which powers most P&P mill
processes."
Moreover, if a pulp or paper mill does use anaerobic digestion, the process will
most likely not be used to digest sludge, Garber added.
"As an example, Boise Inc. has an anaerobic system in the Jackson, Alabama,
mill that is used to treat segregated condensates from the pulping and evaporation
processes which contain sulfur and odorous compounds," he said. "The
condensates are treated in the anaerobic process for biogas generation, which is
used for energy recovery."
6.8 WATER QUALITY DISCHARGE REGULATIONS
As with the municipal wastewater treatment sector and other industrial
manufacturing industries, tougher water quality regulations related to effluent
discharge is an increasingly challenging water treatment issue for the P&P
industry.
In several U.S. regions and particularly the southeast, tighter nutrient criteria
limits could be very difficult for municipal and industrial discharges to meet, P&P
included, Garber said.
"Another emerging regulatory issue includes human health toxic standards,
which could further drive more stringent water quality standards," he added.
Every year the EPA conducts a review of all industrial sectors with established
effluent guidelines, including the P&P sector, to determine whether to revise
those guidelines, Garber said.

49
"The review is based primarily on the relative toxicity of the sector's
discharges. If a more detailed review is determined to be appropriate, EPA will
consider technically and economically available treatment technologies, as well
as other factors. EPA decided not to revise the effluent guidelines for the industry
after a detailed review was undertaken several years ago."
In some specific locales, tighter water quality regulations have already forced
P&P manufacturers to adopt new technologies for treating effluent water to
higher standards. In Spokane, WA, for example, more stringent phosphorus
discharge regulations as part of a total maximum daily load (TMDL) limit for the
Spokane River spurred Inland Empire Paper Company (IEP) to explore
technological strategies that could be implemented for increasing the mill's
wastewater treatment performance in order to meet the new requirements.
As part these efforts, IEP performed pilot scale testing on 10 state-of-the-art
phosphorus reduction technologies including a 1.0 MGD advanced treatment
system that the company commissioned for low-level phosphorus removal from
its effluent. Upon optimization, according to IEP, the polished effluent will be
used as reclaimed water within the mill.
Further, technological initiatives pursued by IEP include the addition of three
moving bed biofilm reactor's (MBBRs) for meeting more stringent permit
limitations, as well as a project that involved testing the first biological advanced
treatment system for nutrient removal using algae. According to the IEP, this
latter technology is showing great promise and will likely be the proving ground
for larger scale applications.
6.9 PLASTIC WASTE
Paper Mills face a huge problem in disposal of the Plastic waste (Residual Plastic)
which is generated from their own Plant. Plastic waste is Hazardous. When
plastics are burnt, harmful quantities of dioxins, a group of highly toxic chemicals

50
are emitted. Dioxins can cause reproductive and developmental problems,
damage the immune system, interfere with hormones and also cause cancer.
(i) Segregation ofwaste plastic is difficult as it is mixed with short fibers, pins,
stones, denims clothes, cotton, fillers, ink particles, metals, non-metals etc.
(ii) Plastic waste generated from the process is being stored onsite in loose
condition (may be bailed) at the paper mill storage yard and thus requires
significant space, additional manpower to handle & transport the plastic
waste from generation to storage area
(iii)Legal, statutory and Social Issues faced by the paper mill inn disposal of
plastic wastes, shall have a direct impact on the mill productions and
profitability
(iv)Government rules “Plastic Waste Management Rules, 2016” further
tightens the role of plastic waste generating companies in mitigating it too.
Paper recycling is the process of mixing used/waste paper with water and
chemicals to break it down. This mixture is then chopped up and heated to break
it down further into strands of cellulose called pulp or slurry. It is then strained
through screens which remove any glue or plastic that may still be in the mixture.
Finally, it is cleaned, de-inked, bleached, mixed with water and then it can be
made into new recycled paper. In a waste paper based paper mill, the feedstock
(used/waste paper) is in the form of different shape & sizes and of different
qualities, consisting of o Paper & Board pieces o Cartons which are poly coated,
plastic laminated or plastic coated o Impurities like pins, staples, nonmetals,
clothes & stone, etc The details of the plastic waste generated from the waste
paper based paper mill / De-inking plants are given below: o 3% plastic waste
generated per ton of Paper o Plastic waste generated shall not be of any defined
properties/characteristics. Its properties, characteristics, ingredients, moisture
level, impurities varies a lot time to time. o Plastic generated shall contain 50-
60% of waste loose plastic - 40-50% of Impurities of pins, staples, non-metals,

51
clothes & stone, etc. Plastic generated shall contain 30- 50%. Moisture
approximately o Bailing process and Efficientstorage (To be compacted &bailed,
transported and stored in the yard) Plastic waste that is generated during pulping
process is then subjected for the bailing process. During bailing, the squeezing of
the plastic waste takes-place and whatever water is there gets squeezed out and
once the bale is properly squeezed and formed in the size, this is tied-up with the
help of wire and taken out with the help of Forklift and stored in a yard.
CONCLUSION
Paper manufacturing process is the difficult and complex process, it requires
mostly the raw materials from the natural sources like timber, bamboo, wood etc.,
and it is a major water consuming process. Each and every processes in pulp and

52
paper mills can release large amount of waste water and also the air pollutants.
The waste water from the effluence can be treated properly and the air pollutants
can be controlled by the air pollution control devices and some methodologies.
The effluent’s parameters and the air pollutan emission level can be checked by
CPCB (Central Pollution Control Board) and TNPCB (Tamil Nadu Pollution
Control Board). This industry follows environmental friendly technologies for
paper manufacturing process.
REFERENCE
1. Biermann, Christopher J. Essentials of Pulping & Papermaking. Academic
Press,1993.
2. Bell, Lilian A. Plant Fibers for Papermaking. Liliaceae Press, 1992.

53
3. Ferguson, Kelly, ed. New Trends and Developments in Papermaking. Miller
Freeman, Inc., 1994.
4. Munsell, Joel. Chronology and Process of Papermaking, 1876-1990. Albert
Saifer Publisher, 1992.
5. Ashrafi, O., Yerushalmi, L., Haghighat, F., 2013a. Application of dynamic
models to estimate greenhouse emission by wastewater treatment plants of the
pulp and paper industry. Environ. Sci. Pollut. Res. 20, 1858e1869.
6. Ashrafi, O., Yerushalmi, L., Haghighat, F., 2013b. Greenhouse gas emission
by wastewater treatment plants of the pulp and paper industry e modeling and
simulation. Int. J. Greenh. Gas. Control 17, 462e472.
7. El-Ashtoukhy, E.S.Z., Amin, N.K., Abdelwahab, O., 2009. Treatment of paper
mill effluents in a batch-stirred electrochemical tank reactor. Chem. Eng. J. 146,
205e210.
8. Hogenkamp, H., 1999. Flotation: the solution in handling effluent discharge.
Pap.Asia 15, 16e18.
9. Pokhrel, D., Viraraghavan, T., 2004. Treatment of pulp and paper mill
wastewater – a eview. Sci. Total Environ. 333, 37e58.
10. Salkinoja-Salonen, M., Apajalahti, J., Silakoski, L., Hakulinen, R., 1984.
Anaerobic fluidised bed for the purification of effluents from chemical and
mechanical pulping. Biotechnol. Adv. 2, 357e375.

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