The document discusses the pulp and paper industry, detailing its production processes, environmental challenges, and the issue of pitch deposits that complicate operations. It outlines traditional and enzymatic methods to control pitch problems, highlighting the environmental impacts of pulp mills and advocating for cleaner production practices. The conclusion emphasizes the need for sustainable methods and the importance of reducing waste and toxicity in the industry.

1. Solving Pitch Problem in Paper and Pulp
Industry
1
Suby Mon Benny
MSc Microbiology
20LS601032

2. An Introduction to Paper
& Pulp Industry
 The pulp and paper industry converts wood or recycled
fibre into pulp and primary forms of paper.
 In the 1800s, there was a shift away from using cotton
rags for paper production. Wood became the most
important source of fiber.
 First mechanical and then chemical methods have
been developed to produce pulp from wood.
2

3. Production process
3
Simplified flow diagram of integrated mill
The production process can be
divided into 7 sub processes:
 raw materials processes;
 wood-yard;
 fibre line;
 chemical recovery;
 bleaching;
 paper production;
 products and recycling.

4. Pulping processes
Pulping aims to separate cellulose fibers from
the wood structure.
Possible types of pulp production are:
Kraft (68%)
mechanical (22%)
semi-chemical (4%)
sulphite (4%)
dissolving (2%).
www.handprint.com
4
4

5. Kraft Pulping
Sulfate or Kraft pulping
was invented in Germany
in 1884 and remains the
dominating technology
today.
It is a process for conversion
of wood into wood pulp,
which consists of almost
pure cellulose fibers, the
main component of paper.
7
5

6. Environmental problems
6
Regulated wastes and
emissions from the pulp and
paper industry include liquid
and solid wastes, air
emissions, and wastewater.
 Air emissions
 Wastewater releases
 Solid waste
6

7. Raw water use
 Pulp mills are big water
users.
 Consumption of fresh
water can seriously
harm habitats near
mills, reduce water
levels necessary for
fish, and change water
temperature, a critical
environmental factor for
fish.
10
7

8. What is Pitch Problem ?
• Pitch are lipophilic extractives from wood and other
lignocellulosic materials.
• Pitch deposits along the pulp and paper
manufacturing processes.
• It is responsible for
• reduced production levels
• higher equipment maintenance costs,
• higher operating costs,
• an increased incidence of defects in the finished products, which
reduces quality and benefits
8

9. Pitch deposition in pulp
processing
• Mechanical pulping only affects slightly the
composition of extractives.
• Chemical pulping saponifies triglycerides.
• Sterol and tri-terpenol esters are much less
affected.
• The wood extractives remaining in the
unbleached pulp are carried over to the bleach
plant.
• The use of totally chlorine free (TCF) bleaching
in place of elementary chlorine free (ECF)
bleaching is increasing the severity of pitch
problems
9

10. Solving the Problem
• Traditional methods:
• Natural “seasoning”
• Adsorption or dispersion of the pitch particles with
chemicals
• Fungal pitch control:
Wood decaying fungi, including
1. white-rot (Funalia trogii,
Bjerkandera, Pleurotus
pulmonarius),
2. brown-rot,
10

11. • Enzymatic pitch control:
• Hydrolytic enzymes- Lipases
• Oxidative enzymes- Oxidoreductases
(laccases- 2,2′-azinobis(3-
ethylbenzothiazoline- 6-sulphonic acid
[ABTS], 1-hydroxybenzotriazole [HBT] ),
lipoxygenases.
3. soft-rot, and
4. sap stain (Ophiostoma, Ceratocystis,
Leptographium) species
11

12. Source: Microbial Enzymes and Their Application
in Pulp and Paper Industry
Abdulhadi Yakubu, Upasana Saikia, and Ashish Vyas

13. Ideal paper mill
• From cleaner production point of view is a chlorine-free and zero-
discharge one, with minimized quantity and toxicity of air pollution and
solid wastes.
• It is seen that closed loops represent the most effective approach to save
both energy and resource consumption and at the same way to decrease
all kind of wastes production.
• Such an approach is developed in the form of paper recycling, different
types of substances re-use during production processes, coproduction and
chemicals recovery.
• Future research can develop more sustainable reuse options for Kraft
pulping solid wastes, as well as pulping methods that result in purified by-
products that can serve as feedstock for other manufacturing processes.
12

14. Conclusion
2
• Lipophilic extractives are responsible for pitch
problems.
• Pulp mills are almost always located near large bodies
of water due to their substantial demand for water.
• Delignification of chemical pulps releases considerable
amounts of organic material into the environment,
particularly into rivers or lakes.
• The process effluents can be treated in a
biological effluent treatment plant, which can
substantially reduce their toxicity.
13

15. 14