Controlled Autoxidation of Heavy Petroleum to produce Carbon Fibre Precursors

The goal of this proposed study is to develop a sustainable, cheap, and efficient pre-treatment method to produce carbon fibre precursors from heavy petroleum following controlled autoxidation (oxidation with air). Carbon fibre is an ultra-light strong material that is very promising in different industries including aviation, auto, military, and sports. The market size of carbon fibre in 2019 was USD 4.7 billion and is expected to increase to USD 13.3 billion in 2029. However, traditional polyacrylonitrile (PAN) based carbon fibre is expensive due to higher raw materials and processing cost that limits the extensive production and use of carbon fibre. Pitch based carbon fibre is less expensive, but the main challenge is the lower fibre strength. Research is going around the world to reduce the production cost and to improve the strength. Both the coal tar pitch and petroleum pitch are being considered, but the focus is mostly on the coal tar pitch. Based on the cost and availability from both the conventional and unconventional crude oil sources, heavy petroleum is highly potential to produce carbon fibre which is one of the few higher-value large global market products. The chemical structure, size, and the presence of aliphatic substitution in polycyclic aromatic hydrocarbons (PAH) fractions are quite different in heavy petroleum compared to coal tar. Heavy petroleum requires pre-treatment to be used as a carbon fibre precursor due to the structural difference and complexity of heavy petroleum. There is a limited effort in the pre-treatment to develop carbon fibre precursor from heavy petroleum. The key features of the carbon fibre are the condensed polymeric structure of aromatics, - stacking and cross-linking that provide the strength. In the current research, heavy petroleum fraction will be pre-treated following controlled free radical oxidation chemistry to impart the properties so that it can be used as carbon fibre precursor. The effects of thermal treatment, oxygen partial pressure, mixing and the gas-liquid interfacial area will be investigated to achieve the goal. It is expected that molecular weight, aromaticity, cross-linking, and the softening point would increase due to the free radical addition (heavier) product formation, removal of lower boiling fractions, and ring closure. It would facilitate the production of carbon fibre precursors from low-value heavy petroleum fractions by using a cheap, readily available, and industrially feasible oxidizing agent- air. Understanding from the current research can also be applied in the area of asphalt hardening, weathering, fouling, storage stability and sludge formation. Kingdom of Saudi Arabia (KSA) is a leading crude oil-producing country that also produces huge heavy petroleum. Value-added products from low-value heavy petroleum is highly desirable. Saudis vision 2030 also includes improvement of the petrochemical production capacity including the production of carbon fibre. Successful production of carbon fibre precursors from low-value heavy petroleum by using economically viable and sustainable route would benefit the KSA in long run. Moreover, this research would lay a foundation to conduct further related research to utilize its petroleum resources efficiently and effectively.