Agglomeration of Metals During Pyrolysis of Chromated Copper Arsenate (CCA) Treated Wood Waste

• Published in: High temperature materials and processes Vol. 27; no. 5; pp. 361 - 368
• Main Authors: Kemiha, Mohammed, Nzihou, Ange, Mateos, David
• Format: Journal Article
• Language: English
• Published: de Gruyter 01.01.2008
• Subjects: Engineering Sciences; specific surface area; CCA wood waste; agglomeration; pyrolysis; heavy metals
• ISSN: 0334-6455; 2191-0324
• DOI: 10.1515/HTMP.2008.27.5.361

The number of waste disposal sites decreases and redundant poles, piling and lumber, which constitute a large volume of material, may not be accepted at the limited number of sites in the future. CCA contaminated wood contains around 1-5% of metal in form of arsenic pentoxide, hexavalent and trivalent chromium compounds and copper sulfate, which act as fungicides and insecticides throughout the life of the wood. While CCA treatment is gradually becoming a banned practice, approximately 4 million tonnes of CCA treated wood is generated in the EU per year, which is set to continue for many decades as the in-service wood is generated in end of its life. Recycling wood waste is important for the effective utilization of natural resources. The charcoal product resulting from CCA treated wood contains Cu, Cr and As. The metals appear as both agglomerates and diffused in the solid matrix. Moreover, during pyrolysis an agglomeration process takes place, which induces not only the growth of existing mineral agglomerates but also the formation of new agglomerates. The objective of the present work is the valorisation of CCA metals and charcoal from treated wood waste. The research aims at understanding and promoting experimentally, at different pyrolysis heating rates, the generation of charcoal with high specific surface area from pyrolysed treated wood waste.