Tomas Pivoras - CP assessment "Vernitas"1 Case Study Textile company Cleaner Production Assessment Tomas Pivoras Kaunas University of Technology Kaunas,

Tomas Pivoras - CP assessment "Vernitas" 1

Case Study Textile company

Cleaner Production Assessment

Tomas Pivoras

Kaunas University of Technology

Kaunas, Lithuania


Information about “Vernitas”

Products: Bulk, polyacryl nitrile (PAN) yarns;

Production capacity: 6.000 tons of yarns per year;

Market: export to EU approximately 70%.


Production processes

Yarn Preparation, sub-processes: Stretch-breaking Rebreaking Intersecting Finishing

Spinning Twisting BulkingDyeing


Auxiliary processes

VentilationBoiler house – heating and steam

productionWater preparationCompressed air production…


Methodology

A ‘top-down’ investigation The company was analyzed on three levels:

Level 1: Main data for black box - entire company; Level 2: Main process data (building a ‘layer cake’); Level 3: Detailed data and measurements for one or two

specific processes.

In the initial phase focus on level 1 and 2. Later level 3 data were collected/measured for

the 2-3 focus areas.


Energy balance

Yarn preparation

7,4%

Bulking8,1%

Dyeing2,5%

Elec. heaters4,4%

Lighting5,0%

Twisting22,9%

Spinning22,1%

Ventilation21,2%

Compressed air

6,4%


Heat consumption

Bulking, steam35%

Ventilation, steam18%

Dyeing, steam16%

Yarn prep., steam

9%

Radiators, hot water

22%


Energy savings (electricity savings)

Electricity savings Elec. savings

Savings Investment Pay back

Units kWh/year EUR/ year

EUR years

Optimisation of humidification system

120,000 7 800* 30 000 3.8

Installation of variable speed drives on fans

551,300 29 000 68 000 2.4

Total 671,300 36 600 98 000 2.7


Energy savings (heat recovery )

Heat recovery Heat savings

Savings Investment Pay back

Units kWh/year EUR/ year

EUR years

Modernisation of heating substation

160,000 7 800* 40 600 5.2

Heat recovery on air compressors

303,300 7 500 15 000 2.0

Recycling of steam condensate in dyeing dept.

290,000 9 500* 14 500 1.5

Total 753,300 25 000 70 000 2.8


Optimisation of the humidification system - replacement of the spraying nozzles Savings by reduction of consumption of both water and compressed air.


Installation of variable frequency drives on fans

Significantly increased energy efficiency of the fans at part load (50-90%), which was approx. 75% of the operation time.


Heat recovery in the compressed air system

N e w s t o r a g e

E x i s t i n g

s t o r a g e

C o m p r e s s o r

6 b a r

C o m p r e s s o r

3 b a r

C o m p r e s s o r

6 b a r

V 6 0 m / s

t = 5 0 - 7 0 C

3

f l o o r i n

t e c h n i c a l

A i r t o t h e

s u m m e r t i m e

F a n

V 6 0 m / s

t = 1 0 - 1 5 C

F a n

3

6 0 m

10,5

m

T e c h n i c a l f l o o r


Recycling of steam condensate in dyeing dept.

Clean condensate

Wat

er to

dra

in

Dyeing block

Air Over flow Filter

Hot water

Steam

To utilization

Clean condensate Hot water

from drying block

* - pump must have static pressure af condensate (~4 m) Fe2O3


Main Cleaner Production projects

1)Treatment of waste water from dyeing department

2)Possibility of recycling the waste water from dyeing department

3)Reduction and substitution of chemicals used in dyeing processes

4)Recycling of cooling water from spinning machines


Minimisation/optimisation of chemicals used1. investigate the use of the chemicals

2. investigate the possibilities to omit the use of the chemicals

3. investigate the possibilities to reduce the use of chemicals (this step should not be considered if the chemicals are evaluated to be hazardous, unless substitution is not possible)

4. investigate the possibilities to substitute the chemicals with alternatives that have less negative impacts on the environment.

Vernitas:

•160 different chemicals

•Total quantity of 26,419 kg.


Zinc emission to effluent

Stop treating the effluent for removal of zinc (Zn)

Find the source of the zinc (Zn) emission in the effluent.

It is much cheaper and more environmental friendly to change the source


Dyes containing heavy metals Name of chemical Concentration

of Zinc (Zn)Concentra-tion of Cop-per (Cu)

Concentra-tion ofChromium(Cr)

Concen-tration ofCobalt(Co)

Astrazon Blau BG 200% 4.2%

Astrazon Blau FGGL 300% 01 4.0%

Astrazon Rot FBL 200% In German ?

Astrazon Blau FGRL 200% 01 4.1%

Cibacron blue FN_R 4.6%

Lanaset Red 2B 1.3%

Lanaset grey G 2.5% 0.79%

Lanaset orange RN 1.1%

Lanaset BORDEAUX B 2.3% 0.2%

Lanaset BROWN B 2.8%

Lanaset BLAK B 3.2%

Irgalan BORDEAUX EL 200% 3.7%

Maxilon Blue SL 200% 4.1%

Maxilon Goldyellow GL granules 200% (nr 148 6946)Maxilon Red GRL granules 200% (nr 1462977)Maxilon Blue GRL granules 300% (nr 1463033)Maxilon blue 5G granules 200% (nr 1486924)


Continual improvements:

Elimination/reducing of: dyestuff containing heavy metals

azo-dyestuff, which splits off carcinogenic amines.

toxic chemicals (T or Tx marked according to EU regulations)

hazardous surfactants giving rise to environmental concerns do to their poor biodegradability, their toxicity and potential to act as endocrine disrupters.

hazardous complexing agent


Wastewater from dyeing department

Wastewater quantity

[m3/h] [m3/d] [m3/month] [m3/year]

Wastewater forreuse

2.0 50 1,100 13,000

Wastewater fordischarge

4.2 100 2,300 27,500

Total waste-water

6.2 150 3,400 40,500


Wastewater treatment plant


Membrane filtration

Feed tank

Feedpump

Recirculationpump

Membranemodule

Back pressurevalve

Concentrateoutlet

Permeateoutlet

Flow controllervalve

Investment:

EUR. 250 000.

Pay back:

17.5 years


Reuse of cooling water from spinning machines Total use of water is about:

24,000 m3/year

Total installation cost is: 818 EUR.

Simple payback period is: 1.67 year.

(not including usage of electricity by water pump and water pumping from well)

Documents

Tomas Pivoras - CP assessment "Vernitas"1 Case Study Textile company Cleaner Production Assessment Tomas Pivoras Kaunas University of Technology Kaunas,