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Conversion of polymeric waste such as plastic and biomass waste to activated carbons via pyrolysis-gasification would be a promising alternative to treat this waste and also produce higher value adsorbent materials. Three different polymeric waste samples pave been investigated to produce activated carbons using a fixed bed reactor. The samples were acrylic textile waste, carbon fibre composite waste and cotton stalk biomass waste. Pyrolysis of samples was performed at different temperatures to recover char/carbon fibre, wax/oil and combustible gases. Steam activation of the pyrolysis chars and recovered carbon fibres was carried out at different activation temperatures and for different durations of activation. In addition, chemical activation and eo-activation of cotton stalk waste samples using phosphoric acid was also carried out in nitrogen and steam/nitrogen atmospheres at different impregnation ratios and temperatures. A wide range of analytical techniques were used to characterise the raw materials and product gases, wax/oil, chars/recovered carbon fibres and activated carbons. The wax/oils, derived from the pyrolysis of acrylic textile waste and carbon fibre composite waste, indicated that they were highly nitrogenated. The gaseous products evolved during the pyrolysis consisted mainly of H2, CH4, C2H6, C3Hg and where cotton stalks were used, high concentrations of CO and CO2. The chemical transformations of chars derived from acrylic textile waste were investigated using FTIR which showed that the formation of condensed aromatic rings with nitrogen at high temperature. The recovered carbon fibres from the carbon fibre composite waste showed very good mechanical properties with up to 93% of that of virgin carbon fibres. The surface area and porosity of physically activated carbons were related to the activation temperature and activation time. Maximum surface areas produced were 752 m2 g" for activated carbon derived from acrylic textile waste, 873 m2 gol for activated carbon fibres and 636 m2 gol for activated carbon derived from cotton stalks waste. Chemically activated carbons, produced from cotton stalks waste using phosphoric acid, showed high surface areas of ~ 1700 m2 gol. The surface area and porosity were related to the impregnation ratio and activation temperature. Co-activation of cotton stalks using phosphoric acid under steam/nitrogen atmosphere led to a considerable increase in both the surface area and porosity of activated carbons compared to that produced using phosphoric acid under nitrogen atmosphere.