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  • What AI and data analysis techniques do catalyst and reactor technology developers offer refiners for higher yields while meeting near-zero emissions specifications?

    Mar-2024

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  • Yoeugourthen Hamlaoui, AXENS, yoeugourthen.hamlaoui@axens.net

    Modern refineries are divided between those that emphasise fuel production, particularly gasoline, and those that prioritise the maximisation of petrochemicals output. Petrochemical-centric refineries seek efficient ways to convert gasoline into high-value petrochemical products while minimising investments. In this context, Axens has developed several combinations of technologies to help refiners adapt their existing assets.

    The combined proprietary technology of Prime-G+ and GT-BTX PluS unveils an avenue for converting gasoline into valuable petrochemical products. In its petrochemical mode with the same configuration, the GT-BTX PluS Extract, a nearly pure aromatic stream with sulphur being the only impurity, undergoes intensified hydrodesulphurisation (HDS) in the Prime-G+ unit, culminating in a high-quality petrochemical benzene, toluene, xylenes (BTX) product. Furthermore, the olefin-rich non-aromatics raffinate stream derived from GT-BTX PluS proves invaluable for FCC recycling, producing significantly additional propylene and enhancing the FCC propylene yield.

    Axens’ FlexEne technology is a low Capex approach that combines two well-established processes: fluidised catalytic cracking (FCC) and oligomerisation. Polynaphtha (awarded the Best Refining Technology 2023 by Gulf Energy Information Excellence) is the Axens oligomerisation technology dedicated to oligomerise olefins contained in the light cracked cut into higher value olefinic cuts, which can be used as high-octane gasoline or high cold properties kerosene or diesel fraction. This combination aims to enhance the capabilities of the FCC process, which is typically the main conversion unit in refineries and is generally oriented towards maximising gasoline and, occasionally, propylene production.

    The innovation in FlexEne lies in its ability to significantly improve the flexibility of product output, allowing for better control over the balance of propylene, gasoline, and diesel production. This flexibility is achieved by selectively oligomerising light FCC alkenes (olefins) for recycle cracking in the FCC unit. By adjusting catalyst formulations and operating conditions, the FCC process can be adapted to operate in different modes, including the maximisation of propylene.

    Prime-G+, GT-BTX PluS, GT-BTX PluS Extract, FlexEne, and Polynaphtha are marks of Axens.

     

    Apr-2024

  • Pierres-Yves Le-Goff, AXENS, Pierre-Yves.LE-GOFF@axens.net

    AI and data analysis techniques can analyse complex refinery processes to identify optimisation opportunities. They can predict optimal operating conditions and adjust parameters in real-time to maximise yields and energy efficiency while meeting emissions standards. Here we give several illustrations:
    • In addition to gasoline and aromatic production from a reformer unit, the other major product is hydrogen. This hydrogen has a low carbon index compared to the one coming from steam methane reforming (SMR) by a factor of around eight. Therefore, any extra hydrogen production is critical. However, to give advice to increase hydrogen production at a first stage, an accurate estimation of the current hydrogen yield is important. This task is not easy as gas flowmeters are not so accurate most of the time. In that context, Axens has developed special tools to accurately follow hydrogen production using in-house data clustering, mass balance closure methodology, and principal component analysis. Based on hybrid models, first principles and machine learning, new set points can be defined to maximise hydrogen and aromatics production.
    • Another example is the optimisation of the recycle gas flow rate. Typically, recycle compressors use steam. Consequently, any reduction of the flow has a direct impact on the unit carbon intensity. Again, based on hybrid models, the recycle gas can be reduced to meet either regenerator coke burning capacity or the requested cycle length for a semi-regenerative unit.
    • Multivariable advanced control embedded to advanced process control uses mathematical models to predict the future behaviour of the process and optimise control actions accordingly. This helps in maintaining optimal conditions for catalysts and reactors to achieve higher yields while minimising emissions.
    • Creating digital twins of refining processes allows for simulation and testing of different scenarios without affecting the actual operation. Applied to the aromatics complex, data densification techniques coupled with real-time monitoring enable an aromatic production increase by maximising benzene precursors in the continuous catalyst reforming (CCR) unit inlet. Operational improvements such as octane optimisation in a catalytic reforming process as a function of pool requirement or hydrogen-to-hydrocarbon molar ratio adjustment minimising energy consumption will favour CO₂ emissions reduction.

     

    Apr-2024


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