INTERNATIONAL CLEANER PRODUCTION INFORMATION CLEARINGHOUSE

Case Study #273

1. Headline: Internal recycling at a French glass packing

plant reduces water consumption.

2. Background: The factory Saint-Gobain Emballage in Cognac

specializes in the manufacture and packing of glass with a

production capacity of 1150 tons/day. The kilns operate

continuously and are cooled in a closed circuit (120 m3/d

of make-up water). This case study was carried out in

1992.

3. Cleaner production Principle: Internal recycling

4. Description of Cleaner Production Application:

Information about the process and wastes

On each machine a gutter drains off the glass particles in

the basement during the cutoffs. Glass and water are thus

discharged into a granulator where scraping chains remove

the glass to the recycling plant. Upper flow water carries

along glass particles as well as drops of full oils,

machine grease and soluble cutting oils. This water can

reach a temperature of 60 to 80C.

Gutters drained these waters with the rain water to the

River Charente i.e. 1500 to 3200 m3/d with the following

characteristics :

SS : 150 to 300 mg/l

BOD : 10 to 50 mg/l

COD : 50 to 150 mg/l

Hydrocarbons : 5

to 20 mg/l

pH : 7.5 to 7.8

SGE built a treatment and recirculation plant for this

machine water, rather than remaining in open circuit and

carrying out a more expensive physico-chemical treatment.

Upper flow is discontinued and the water, collected

separately from the rain water, is pumped to a settling

and oil removal tank, then recirculated towards the

machines. The sludge with glass particles is remelted with

the ground glass and the oils removed by a patented

collector.

Material / energy balance and substitution

Maxi discharge : 250 m3/d, i.e. 10 % of the recommended

value.

5. Economics:

Cost of direct investment: 4 500 000 FF (1992)

Operation and maintenance costs: About 50 000 FF/year

6. Advantages: Applying the standards in force allocated to

the factory in Cognac by their order of authorization for

exploitation. Reducing the water consumption.

7. Constraints: The glass particles sludge easily becomes

solid.

Planning an aero-cooler on the water circulation loop.

In order to avoid any disturbance in the recirculation,

the water washing the parts of the machines is treated

separately on an oil removing drum.

8. Contacts:

Agence de l'Eau Adour-Garonne

M. GARIADOR

TEL: 33 61.36.37.38

M. HARRIS

Responsible for SGE investments

TEL: 33 16.1.47.62.39.09

Saint Gobain Emballage (SGE)

Chateaubernard

16103 COGNAC - France

TEL: 33 45.82.51.99

FAX: 33 45.36.12.80

M. Maton

M. Chatenet

Office International de l'Eau

Direction de la Formation et des Etudes

rue Edouard Chamberland

87065 Limoges Cedex, France

TEL: 33 55114770

FAX: 33 55777115

9. Keywords: France, crystal and glass, packaging,

recycling, glass, ISIC 3620

10. This case study was submitted to UNEP IE in 1994 by the

French Office International de l'Eau. It has not undergone

a formal technical review.