Production and characterisation of pitch based carbon fiber from different organic wastes

In this study, pitch based carbon fiber production was investigated by using biomass, polymer and petroleum refinery wastes and the study was carried out through three stages. In the first step, pyrolysis of two different biomass samples (walnut shell and peach stone) and different polymers (PET, PS and PVC) together with co-pyrolysis of biomass/polymer mixtures were performed using TGA/MS/FT-IR. Pyrolytic activation energies were calculated by different iso-conversional methods and the gases evolved during decomposition were determined. In the second stage, pyrolysis was performed in a fixed bed reactor and effects of temperature and co-pyrolysis on product yields and properties were investigated. In the last step, production of pitch based carbon fiber production was investigated. To this end, hybrid pitches were produced by oligomerization of tars with pyrolysed fuel oil (PFO) using bromination/dehydrobromination process and effects of tar characteristics, blending ratio and bromine amount were determined. Then, pitches with the same softening point were synthesized from different tars and then carbon fiber production was carried out. After melt spinning, stabilization and carbonization, properties of the produced carbon fibers were determined apart from the softening points of the pitches. The characterization results show that tensile strength and elastic modulus of the carbon fibers depend on the structure of the raw materials used in pitch production. As a result, an environmentally friendly, alternative method for the production of general purpose carbon fiber using biomass, polymer and petroleum refinery waste is demonstrated.