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Crude-to-Chemicals (CTC): a straight-forward route for a strategic turn

Feb 17 2021

Written by Axens

In the background of fuels demand shifting towards petrochemicals growth, Crude-To-Chemicals (CTC) projects are arising to manufacture in the same dynamics and with the expected flexibility level, the coveted high-value compounds (HVCs) and ever cleaner fuels, thus responding to global environmental preservation. 

These new-generation projects fit into the context of the megatrends transforming the world of today and tomorrow. The CTC complexes deploy innovative technology routes making it possible to upgrade most of the Bottom-Of-the-Barrel therefore giving rise to the high added-value petrochemical intermediates, taking into account both client and market specificities.

Executive Summary

  • The increasing trend for the main petrochemical intermediates compared to the one of the more tenuous fuel demand growth is driving the need for process flexibility to the expanding chemical value chain.

  • In response, new generation projects, CTC complexes, with their ultimate degree of integration between a refinery and a petrochemical plant, are designed for squeezing the Bottom-Of-The-Barrel to lift up the chemical yield.

  • Various mature and breakthrough technologies are combined to make the most of the Bottom-Of-the-Barrel, and this up to the targeted pure molecules, among which the ethylene, propylene and the paraxylene.

  • The interlinking between the three blocks; i.e.; conversion, olefins and aromatics, forming a CTC complex generates the synergy essential to maximal streams valorization.

In phase with emerging trends and patterns

Throughout history, the refining industry has known how to adapt in order to meet the new challenges of global oil consumption patterns. The constant evolution of refining over time towards chemical yield was achieved in four main stages up to the ultimate integration degree between refining and petrochemicals materialized by the Crude-To-Chemicals (CTC) complexes corresponding to a chemical yield greater than 40%.



Innovative Combination of Technologies at the very heart of CTC complexes

Combinations of mature and cutting-edge technologies are implemented to push the resid conversion to maximum leading to naphtha (light & heavy) or directly to raw olefins.

CTC complexes are made of three blocks : the conversion one, the aromatics one referring to heavy naphtha processing and the olefins one for light naphtha and light ends processing.

CTC complexes tailor-made approach

A holistic view, achieved through a client-oriented multi-criteria analysis, is essential to ensure a viable CTC project implementation since each CTC project is unique.


Are you up to shift to CTC ?

You are proposed to discover how to take up the challenge of ultimate conversion leading to the highly coveted aromatics and olefins. Of course, Axens’ recommended pathways are customized to match your project specificities and Axens supports you at each phase of your project.

The structure of a CTC complex is organized around the two key routes :

Resid conversion to Naphtha :

  • The H-Oil® technology in association with maxi naphtha fixed-bed hydrocrackers, Diesel & VGO HyK™, is involved in this strategy and succeeds in reaching the naphtha production even processing the most refractory feeds. Squeezing even more the matter is complemented with Solvahl™ or FLEXICOKING™.
  • The light naphtha is routed to the steam-cracker, whose olefinic streams have to be selectively hydrogenated. Besides, Axens offers a range of technologies to produce high-purity 1-butene and 1-hexene co-monomers used to manufacture specific high-value polymers.
  • The heavy naphtha is dedicated to the Aromatics block is designed to synthesize base petrochemical products BTX (Benzene – Toluene – Xylenes). Its first stage, the Aromizing™, aims at increasing the aromatic content. There follow several units strongly inter-connected, together forming the Paramax® suite, taking the most of recycled flows through reprocessing, where extraction, rearrangement and the xylenes loop are completed the scheme in order to maximize the production of the added-value molecules. Overall, it has to be noted that multiple technologies and schemes are available to match any project specificities, always with focus on maximal global heat integration.

Resid conversion to Olefins :

  • Maximizing propylene production with the new breakthrough HS-FCC™ technology, high severity FCC boosting the olefins production.
  • The Hyvahl™ technology, deep feed pretreatment equipped with its patented Permutable Reactor System (PRS) upstream the HS-FCC™ maximizes the overall olefins yield.
  • This route fits into a more complete scheme where non-olefinc products are valorized through dedicated post-treatments before being processed either in the steam-cracker or the ParamaX® suite.


Full set of services

Axens supports clients throughout the entire unit life cycle, from feasibility study up to unit start-up and follow-up. As the CTC projects involve high-performance technologies, it is of utmost importance to benefit from the whole range of solutions.

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