Prospects of refinery switching from conventional to integrated: An opportunity for sustainable investment in the petrochemical industry

•The emerging virgin crude-to-chemicals technology (CTC) can provide an opportunity for integrating operational refineries with chemicals.•Producing sustainable feed for the chemical and petrochemicals.•The refinery feedstocks have a gradual shift toward heavier crudes and residue.•A combination of both thermal and catalytic processes can also be used to achieve the effective utilization. In recent years, the oil market has witnessed high volatility due to unstable demand and supply. Considering the price volatility and stricter environmental regulations, there is a possibility of a decline in the demand for transportation fuels, which will force refiners to explore alternate ways to improve the yield of high-value products, to keep their margins high. In recent years, demand for petrochemicals has witnessed tremendous growth, and there is a dynamic market for olefins and monomeric (building blocks) hydrocarbons. The emerging virgin crude-to-chemicals (CTC) technology can provide an opportunity for integrating operational refineries with chemicals. The integration of refining with the production of high value-petrochemicals can lead to a framework that will add value to both sectors (upstream and downstream). Integration has been proven to be environmentally driven by utilizing various refinery waste and by-products. The importance of thermal and catalytic processes in the integrated refinery is high, particularly the process of integrated gasification combined cycle (IGCC) that generates electricity and by-product as a feedstock for chemicals. On the other hand, high demand for petrochemicals indicated a predictable growth in recent years, mainly driven by the commodity product requirement. Hence, this review critically discusses the current oil price variation, heavy oil production, and technical challenges to convert heavy crude to chemical (c-t-c) or petrochemical (c-t-p). Moreover, considerable flexibility is emphasized as a holistic approach to deal with unconventional feedstock (using thermal and catalytic methods) to produce sustainable feed for the chemical and petrochemicals.