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Pirelli Ambiente Renewable Energy

Quality control in SRF production

Luca Zucchelli

QUOVADIS WORKSHOPRome - October 24, 2007

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Quality in SRF production

The Italian drivers that move towards a total quality management system in SRF production plants are:

•Normative: the article 229 of the Decree n° 152/2006 points out that the high quality SRF, produced whithin a production process adopting a quality management system based upon the standard ISO 9001, and destined for effective use within a co-combustion process in energy production plants and in cement kilns, is excluded from the waste context.

•Economical: the SRF producer has to certify its production process in order to fulfill the customer requirements in terms of guaranteed technological and environmental performance of the combustible.

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The product and process control

NCV

Chlorine

Mercury

Fundamental parameter to be controlled

Economical parameter

Technological parameter

Environmental parameter

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cdr-p

THE CHLORINE PROBLEM

A TECHNOLOGICAL PROBLEM

The critical phase is the SFR oxidation in the rotary kiln

Dioxins and Furans genesis

High temperatures ~ 2000°C

No changes with/without HQ-SRF

Analysis show dioxins and furans values extremely lower compared

to WID limits

Corrosion and clogging problems

By-pass intallation to devert the flues gases

avoiding the alkaline-chlorine salts

condensation

Analysis of the chlorine content of the SRF and of the raw materials

Quality Management System

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cdr-p

THE CHLORINE PROBLEM

THE METHOD

• Upgrade of the method: difficulties in measuring, with the traditional method for calorimetric bomb + potenziomentric, the chlorine content of materials with a content of plastics and rubber exceeding 10% evaluation of the possibility to extend the method to all SRFs

• Samples size shredded size <1 mm

THE RESULTS

• The values obtained are between 0,4 and 0,8%

• Difficulties in classification (overlapping problem)

NEW TECHNOLOGIES

• Development of the NIR technology for low chlorine SRF production and to reduce the variability of data obtained

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Single Measurements (2006)

0,000

0,100

0,200

0,300

0,400

0,500

0,600

0,700

0,800

0,900

1,000

1,100

1,200

1,300

1,400

1,500

0 10 20 30 40 50 60 70 80 90 100 110 120 130 140 150 160 170 180 190 200 210 220 230 240 250

Days

Chlorine %

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Single Measurements compared to the average of last 10 values (2006)

0,000

0,100

0,200

0,300

0,400

0,500

0,600

0,700

0,800

0,900

1,000

1,100

1,200

1,300

1,400

1,500

0 10 20 30 40 50 60 70 80 90 100 110 120 130 140 150 160 170 180 190 200 210 220 230 240 250

Days

Chlorine %

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Average of last 10 values: trend 2004

0,000

0,100

0,200

0,300

0,400

0,500

0,600

0,700

0,800

0,900

1,000

1 8 15 22 29 36 43 50 57 64 71 78 85 92 99 106 113 120 127 134 141 148 155 162 169 176 183 190 197 204 211 218 225 232 239 246

Chlorine %

Days

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Average of last 10 values: trend 2005

0,000

0,100

0,200

0,300

0,400

0,500

0,600

0,700

0,800

0,900

1,000

1 9 17 25 33 41 49 57 65 73 81 89 97 105 113 121 129 137 145 153 161 169 177 185 193 201 209 217 225 233 241 249 257 265

Chlorine %

Days

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Average of last 10 values: trend 2006

0,000

0,100

0,200

0,300

0,400

0,500

0,600

0,700

0,800

0,900

1,000

1 8 15 22 29 36 43 50 57 64 71 78 85 92 99 106 113 120 127 134 141 148 155 162 169 176 183 190 197 204 211 218 225 232 239 246

Days

Chlorine %

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THE HEAVY METALS PROBLEM

AN ENVIRONMENTAL PROBLEM

Mercury (Hg), because of its volatility, is the environmental parameter to keep under control in SRF production

Possibility to apply the same statistical method used for chlorine measurement, but the need of a suitable number of assays for the statistical analysis implies the choice of the right method for the collection of data.

Spectrometry Atomic Absorption

• relatively cheap

• user friendly

• limited analysis time

Suitable number of Hg measurements

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montly Hg measurements: January 2007

0,0000

0,1000

0,2000

0,3000

0,4000

0,5000

0,6000

0,7000

0,8000

0,9000

1,0000

0 10 20 30 40 50 60 70

samples

Hg

(p

pm

)

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Comparison between single measurements and the avarage of last 10 values

0,0000

0,1000

0,2000

0,3000

0,4000

0,5000

0,6000

0,7000

0,8000

0,9000

1,0000

1 3 5 7 9 11 13 15 17 19 21 23 25 27 29 31 33 35 37 39 41 43 45 47 49 51 53 55 57 59 61 63 65

samples

Hg

(p

pm

)

Lot December

Lot January

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FIRST YEAR Planning ImplementationExternal

comunication

Maintenance

Personnel

Management

Tecnicians

Employees

Operators

EquipementsHW and SW

Equipments

Outsourcing and other resources

Consulting

Training

Certification Body

Internal -External

laboratory

QUALITY COSTS

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SECOND / THIRD YEAR

QMS maintenance

and data records

Sampling and raw material

analysys

Equipments maintenanc

e

Product and process control

Personnel

Management

Tecnicians

Employees

Operators

Equipements

HW and SW

Equipments

Outsourcing and other resources

Consulting

Training

Certification Body

Internal -External

laboratory

QUALITY COSTS

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The statistical method, used to evaluate the trends of chlorine and mercury data, allows to establish any drift from the customer requirements due to undesired materials that could be entered the production process.

Moreover this method can be used as predictive method for recognizing anomalous trends of the mercury and chlorine concentration in order to intervene promptly avoiding dangerous effects for the SRF final user and for the environment.

CONCLUSIONS

The QMS support is fundamental for SRF producers, providing all the necessary instruments to keep the process and the product under control

and best fulfill all the customer requirement.