enzymatic deinking - a bright solution with a bright future

NOVOZYMES PRESENTATION [email protected]/8/20101

Md. Hanif Shaikh

Application Scientist

Novozymes, India

[email protected]

8-Oct-10

�What are enzymes?

� Enzymatic catalysis sequence

� Deinking

� Enzymatic Deinking technology

AGENDA

10/8/20102 NOVOZYMES PRESENTATION [email protected]

� Case study

� Potential benefits of enzymatic deinking

� Summary

What are enzymes?

Enzymes characteristics:

� Proteins


� Proteins

� Natural organic catalysts

� Small amounts needed

� Efficient, fast and specific

� Easy to control

� React under mild conditions

� No adverse effect on environment

� NOT living organisms

Enzymes are present in all living cells, converting nutrients into energy and building blocks, and making new cellular structures.

Industrial enzymes are made by microorganisms.

Enzymes are proteins10/8/20104 NOVOZYMES PRESENTATION [email protected]

http://www.labbench.com/sample/active.html

• Enzymes have a compact 3D-structure

• Molecular weight of 10-100 kDa

• Size: globular with diameter = 5-10 nm

• The Active Site (small part of the enzyme)

determines functionality

• Enzymes are nature’s catalysts

• Accelerate reactions that normally

require high temperatures or extreme pH

• Unchanged by the reaction (i.e. they are

not consumed or destroyed)

• Enzymes are very specific with respect to

Enzymes are organic catalysts10/8/20105 NOVOZYMES PRESENTATION [email protected]

• Enzymes are very specific with respect to

substrate and reaction

• e.g. cellulases are specific for cellulose &

lipases are specific for lipids.

How does an enzyme work?

Even when different substrate molecules are present, only those that have the specific complementary shape are able to bind with the enzyme's active site.


Binding site

Mechanism of pH and Enzyme Function

� When the pH changes, the active site progressively distorts.

� In the presence of either excess H+ or excess OH-

ions, the globular protein's shape is


protein's shape is altered.

� The active site is distorted and the enzyme cannot catalyze reactions.

NOVOZYMES PRESENTATION [email protected] 10/8/2010

Deinking .......

Deinking is the industrial process of removing

printing ink from paper fibers of recycled paper to

make deinked pulp.

The key in the deinking process is the ability to detach

.

The key in the deinking process is the ability to detach

ink from the fibers. This is achieved by a combination

of mechanical action and chemical means.

Paper is one of the main targets for recycling. A

concern about recycling wood pulp paper is that the

fibers are degraded after being recycled 4–6 times

the fibers become too short and weak to be useful in

making

�Enzymes efficiently improves deinking operations thus extending

the use of recycled paper without compromising brightness or

strength properties.

�Enzymes offers an optimized, reliable, and predictable effect

Enzymatic Deinking


�Enzymes is designed to be effective, yet gentle on fibers and

efficient in enhancing liberation of ink from the fiber surface.

Deinking involves dislodging ink particles from fiber surfaces and

then separating the dispersed ink from the fiber suspension by

washing or flotation.


VVVVVVVVVVVV VVVVVVVVVVVV VVVVVVVVVVVV

Shear

Enzymatic Deinking Technology

VVVFiber

VVVVVVVVVVVV

Fiber

Ink/Toner

Enzymes

Enzymes improves ink separation from fiber by attacking ink & fiber interface

• Result in better ink release• Less ink deposition back to fiber; Improve fiber cleanness• Brightness increase and dirt reduction.

• Combination with the right surfactant is key to success.


Enzymatic Deinking technology

degraded starchstarch

� Enzymes (Amylase) assist ink release by degrading the starch in coating and sizing.

� Enzymes also degrade starch associated to ink particle surface to help improve flotation

efficiency (as illustrated below).

� Expose the hydrophobic nature of ink particles

� Improve ink removal across flotation cells

� Result in higher delta brightness across flotation cells

Enzymes

hydrophobichydrophilic

degraded starchstarch

Case Study


Main Objective:

• To reduce deinking Chemical Consumption and cost benefit.

Other Objectives:

• Cleaner recycled white water

• Increase brightness of Feed in Floatation Cell• Increase brightness of Feed in Floatation Cell

Background:


Trial Target: Deinking Chemical Consumption with cost benefit.

Furnish: MOW, CBS, Old News print

Final product = Writing & printing

Deinking Process: Flotation CellDeinking Process: Flotation Cell

Chemical used: Sodium hydroxide, Hydrogen peroxide &

Surfactant

Target Brightness : 80 ISO

Process flow:


Enzymes

Application Conditions:


Dosing Point: Pulper

Enzyme Dosage: 0.280 kg/ton of dry pulp

Retention times in Pulper: 20 minutes

Treatment conditions: pH = 8.5 (Initial pH:10)

Temperature = ~50°CTemperature = ~50°C

Trial period: 7 days


Results:Increasing of Feed Brightness

• Brightness gained about 1-1.5

points at Feed of Flotation Cell

with enzyme treatment as

compared to Control.

.

• Significant brightness

improved at Feed of

Flotation Cell and darker

reject at Flotation Cell Reject

Line. This is due to more inks

can has been removed through

Flotation Cell Reject and

cleaner. Thus, the white water

recycle back to Pulper becomes

cleaner and less ink content.

This trial is made on CBS = 25%, Multi grade = 25% & records = 50% and shows the typical effect of enzyme cocktail on brightness


Results:Reduction in residual ink

• From this graph it can be

studied that there is significant

reduction in residual ink count

at various process step.

.


Results:Reduction in residual ink

� The Flotation Cell Reject Line

which was treated with

Enzymes was darker when

compared to control (without

enzyme treatment).

.

enzyme treatment).

� This indicates the reduction in

residue ink on fiber.

With Enzyme TreatmentWithout Enzyme Treatment


Chemical Consumption

• Enzymatic Deinking was able

to reduce sodium hydroxide by

almost 50 % .

• Reduction in Sodium Silicate

100%

80%

100%

120%

5

6

7

Percenta

ge s

avin

g

Control Enzymatic Deinking (Kg/T) Percentage Saving

.

• Reduction in Sodium Silicate

by 37 %.

• With complete elimination of

hydrogen Peroxide in the

Pulper

Cost benefit by using enzyme cocktail

50%

37%

0%

20%

40%

60%

0

1

2

3

4

Sodium Hydroxide

Sodium Silicate Hydrogen Peroxide

Surfactant Biodeink D

Percenta

ge s

avin

g

Deinking Chemistry

Kg/Tone


Potential Benefits of Enzymatic De-Inking

� Reduce or eliminate the use of certain

chemicals.

� Improve the pulp brightness.

.

� Improve the pulp brightness.

� Lower dirt count.

� Water/yield saving.

� Improved drainage properties.

� Mild processing conditions.

� Reduced effluent toxicity.

� Environmental friendly.

� Reduce overall production cost.


Summary

• Enzymatic deinking process enhance the physical properties, higher brightness and lower residual ink when compared to chemically de-inked pulp.

In the pulping arena, enzymatic based deinking shows promise as a means of reducing chemical use and wastewater treatment

.

pulp.

• Enzymatic deinking works at neutral or slight alkaline environment which reduces overall chemical requirement and minimizes yellowing of reclaimed paper after alkaline deinking.

• Reduce chemical usage means lower waste treatment cost and reduce environmental impacts.

treatment


THANK YOU FOR YOUR THANK YOU FOR YOUR ATTENTION

NOVOZYMES PRESENTATION23 10/8/201010/8/201023 NOVOZYMES PRESENTATION [email protected]

THANK YOU

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enzymatic deinking - a bright solution with a bright future

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