This work is focused on the preparation of an activated charcoal by carbonization of waste tire rubbers (WTRs) and its evaluation for shape-stabilization of dodecyl alcohol (DDA) as an organic phase change material (PCM) used for thermal energy storage (TES). In the composite, DDA had TES function as carbonized waste tire (CWT) acted as supporting and thermal conductive frameworks. CWT prevented leakage of melted DDA during phase change due to its good adsorption ability until the weight ratio of DDA reached 78%. The shape-stabilized composite PCM was characterized by FT-IR, XRD, SEM, DSC and TGA techniques. The DSC results revealed that the composite PCM had very appropriate melting point of 21.68 +/- 0.12 degrees C and considerable high latent heat capacity of 181.6 +/- 1.2 J/g for thermoregulation of buildings. Compared to DDA, thermal degradation temperature of the composite PCM was extended as about 50 degrees C. The 500-cycled composite PCM had still showed reliable TES properties. Additionally, thermal conductivity (0.431 +/- 0.010 W/m.K) of the composite PCM was measured as about 2.3 times higher than that of DDA. The heating and cooling periods of the composite PCM were reduced by 17.2 and 20.0%, respectively compared to that of DDA due to its enhanced thermal conductivity. All results suggested that the produced CWT as low-cost and environmental friendly supporting material can be evaluated for absorbing PCMs used for passive solar TES utilization in buildings. (C) 2019 Elsevier Ltd. All rights reserved.