Activated carbon production from char issued from used tyres pyrolysis: Industrial improvement

Activated carbons have been prepared from used tyres and their characteristics were investigated. Tyres were first pyrolysed at 800 °C, during 45 min in an inert atmosphere in the Avonmouth's industrial pyrolyser with a throughput of 1 t/h (Compact Power Ltd, Bristol, UK). The resulting chars were subsequently activated with steam in the presence of carbon dioxide at 970 °C in a batch pilot monohearth reactor at NESA facility, Louvain-la Neuve, Belgium. Activated carbons produced at various times of activation, were characterised using gas (He/N 2 ) phase adsorption. B.E.T surface areas increase with the time of activation reaching a maximum after 2.30 hours residence time. A longer activation time leads to the destruction of the pores. Activation at high temperature leads to pores of large dimensions although a non general homogenous situation appeared in SEM analysis. The maximum B.E.T surface area was found to be around 430 m 2 /g. Measures of B.E. T surface areas of activated carbons prepared in this study were found to be similar to a commercial carbon NORIT® GL 50. For further industrial development in a continuous process, there will be a need to pelletize the char before its activation for better efficiency.