1. Headline: A cryogenic process for paint removal from steel structures, using liquid nitrogen instead of acids or pyrolithic oven. 2. Background: February 1993 3. Cleaner Production Principle: Material substitution 4. Description of Cleaner Production Application: The process for paint removal is based on liquid nitrogen's ability to quicken cooling. The differing rates at which the material of the structure and paint coat contract results in cracks in the paint. By means of mechanical action the paint coat is then removed. The resulting solid waste can be used for the production of plastic objects. Specifically, objects to be treated are placed in a tank containing liquid nitrogen (-196C). Due to the different contraction between the steel structure and paint coat, the paint cracks and can be removed by mechanical action. The process can be realized in a continuous and completely automated plant. Conventional processes utilize acid dripping or pyrolitic ovens and produce pollutants. Liquid nitrogen, chemically inert, is already in the atmosphere and can be obtained at low cost. This type of process does not produce liquid waste. The solid waste that is produced can be recovered and utilized to produce plastic objects. Existing plant capacity is 2500 Kg/h of objects to be treated. The technology has been fully implemented and in operation since 1990. It is covered by a patent. 5. Economics: Referring to 2.500 Kg/h of treated objects the investment cost is $220.000 - $250.000 US. Payback time is 1/1.5 year. 6. Advantages: In addition to the benefits outlined above, nitrogen is a comparatively low cost raw material and the objects processed by this technology have a life span five times longer compared to those produced by other processes. 7. Constraints: This process has a high productivity until 3.000 Kg/h. 8. Contacts: Sig Attilio Bernasconi BETA RICERCHE Via Caduti, 6 28015 Alzate di Momo (NO) ITALY TEL: 39-321 926520 FAX: 39-321 925060 Mr G Bardone ENEA CRE Casaccia Dip Ambiente Via Anguillarese 301 00060 - S Maria di Galeria ROME Italy TEL: 396 3048 6662 fax: 396 3048 3220 9. Keywords: Italy, paint removal, material substitution, cryogenic process, nitrogen, acid, pyrolithic oven 10. Reviewer's comments: This case study was submitted to UNEP IE in 1994 by Italy's ENEA. It was reviewed and edited by UNEP IE in July 1995. It has not undergone a formal technical review.