ERTC 2025
hot spots and enhances catalyst perfor- mance. Energy efficiency is also a bene- fit as Magshift catalyst reduces the need for high-pressure compressors or blow- ers. Pilot plant testing confirms that the new catalyst achieves high conversion rates, positioning it as a promising solu- tion for optimising hydrogen production and advancing a more sustainable energy future. Building upon this success, UNICAT is actively developing Magshift HTS for high- temperature shift applications, further expanding the potential of this innovative catalyst technology. Notes a All the catalysts were first heated under nitro- gen flow at 200°C for two hours to remove moisture. After the drying stage, hydrogen was introduced for catalyst reduction, under controlled conditions at 200°C for four hours. Subsequently, a feed comprising 20% CO in a carrier gas was introduced at a rate of 220 ml/
limitations, resulting in wasted surface area and active metal area. The resultant high pressure drop in reac- tors from the use of traditional WGS cat- alysts increases energy consumption for pumping and compressions. High pres- sure drop also leads to uneven flow dis- tribution and hot spots, which reduce catalyst effectiveness, leading to catalyst degradation. Magshift catalyst addresses these chal- lenges through its innovative textured sphere design and unique carrier technol- ogy, featuring a tailored pore size distri- bution that optimises the accessibility of active sites. The larger macropore struc- ture facilitates quick product and heat dissipation, reducing catalyst sintering, extending catalyst life, and improving efficiency. The benefits of switching to Magshift catalyst for WGS include improved flow dynamics, as reactant gases make bet- ter contact with catalyst, which eliminates
gen flow at 200°C for two hours to remove moisture. The hydrogen yields and CO₂ yields were consistent with those of com- petitive products. Except for Traditional catalyst 4, which exhibited lower catalytic activity (52-85% conversion), the other Traditional catalysts 1-3 demonstrated catalytic activity similar to the textured sphere catalyst (91-100% conversion) ( Figure 3 ). This indicates that even with only 16% CuO, the new catalyst compares favourably with the most active traditional LTS catalysts tested. Summary The WGS reaction is critical for enhancing hydrogen production and reducing carbon monoxide emissions in various industrial applications. Traditional WGS catalysts, while effective, face challenges such as causing high pressure drop in fixed-bed reactors due to their high attrition and small pellet sizes, temperature sensitivity, susceptibility to poisoning, and diffusion
min along with 0.88 ml/min of water over 90 ml of catalyst in an electrically heated reactor and maintained at 300°C. b After the drying stage, hydrogen was intro- duced for catalyst reduction, under con- trolled conditions at 200°C for four hours. Subsequently, a feed comprising 10% CO in a carrier gas was introduced at a rate of 220 ml/ min along with 0.5 ml/min of water over 90 ml of catalyst in an electrically heated reactor and maintained at 200°C. References 1 Baraj, E., Ciahotný, K. and Hlinčík, T., 2021, The water gas shift reaction: Catalysts and reaction mechanism, Fuel , 288, p.119817. 2 Palma, V., Ruocco, C., Martino, M., Meloni, E. and Ricca, A., 2017, Catalysts for the conver- sion of synthesis gas, Bioenergy systems for the future, Woodhead Publishing, pp.217-277. 3 Stuckey, M., 2023, A step change in cata- lyst development, Hydrocarbon Engineering Whitepaper: Catalyst Evolution.
Contact: paul.hudson@unicatcatalyst.com
Turning iron contaminated feeds into profit: an effective approach to FCC catalyst protection
Jeremy Mayol and Marie Goret-Rana JOhnson Matthey
ers to increase catalyst consumption and accept lower yields.
The rising availability of lower-value feed- stocks, such as oil sands and shale-derived crudes, offers refiners new, profitable opportunities. Yet, these unconventional crudes contain higher levels of metals, particularly iron, that create process- ing challenges. In fluid catalytic cracking (FCC) units, feed iron accumulates on the base catalyst, hindering cracking activ- ity, increasing coke and hydrogen produc- tion, and reducing fluidisation. The result is increased usage of base catalyst, lower process efficiency, and higher operating costs. With the right strategy, refiners can turn opportunity crudes into valuable products. This article outlines the impact of iron poi- soning, the limitations of conventional mitigation methods, and how Johnson Matthey’s CAT-AID TM metals trap addi- tive can effectively alleviate iron contam- ination. Mechanisms and a refinery case study are also presented. Impacts of iron poisoning Feed iron typically enters FCC units as porphyrins or naphthenates. Due to their size, these species are unable to diffuse into the internal structure of FCC cata- lyst particles. Instead, they preferentially deposit and accumulate on the catalyst surface. Over time, they form low-melting- point eutectics deposits or ‘iron nodules’. Their effects include: • Blocked pores and loss of catalyst activ- ity and conversion. • Erratic catalyst circulation due to reduced apparent bulk density. • Reduced liquefied petroleum gas (LPG) olefinicity from secondary reactions.
Conventional mitigation Traditional strategies include:
• Increased catalyst make-up or addition of purchased equilibrium catalyst (Ecat) to dilute iron. • Reformulated base catalyst with higher matrix content or iron-trapping functionality. • Reduced feed rate or higher metals feed to allow for easier operations on the unit. These provide partial relief but raise costs and seldom eliminate poisoning entirely. Higher catalyst addition rates often remain necessary,² which has spurred interest in metals trap additives.³ , ⁴ Fundamental insights into iron trapping Recent Johnson Matthey studies using high-resolution transmission electron microscopy (HR-TEM) and energy disper- sive spectroscopy (EDS) analysis of Ecat particles from commercial FCC units con- firmed that: • Iron concentrates on the outer 0.5-3 μm of catalyst particles.² • Deposits consist of 5-20 nm iron oxide nanoparticles in an amorphous iron-silica matrix. • The glassy iron–silica layer seals pores and blocks diffusion.² • Iron shows minimal mobility within parti- cles but can transfer between particles in the regenerator, most likely through colli- sions. Silica (especially from the Y-zeolite) plays a key role in this mobility, migrating under FCC regenerator conditions⁸ and promoting the growth of iron nodules.⁵ , ⁶ , ⁷
Figure 1 Scanning electron microscopy with energy-dispersive spectroscopy (SEM-EDS) mapping of Ecat showing the elemental distribution on the cross-section of particles including Ecat and CAT-AID additive. CAT-AID particles effectively trap iron and silica as evidenced by the rings on the surface. Vanadium rings on CAT-AID particles are clearly evi- dent, too (arrowed)
Figure 2 SEM images from Ecat samples before and after the addition of CAT-AID additive
(H₂S) in the riser and releasing it as SOx in the regenerator. Iron poisoning becomes significant above ~0.2 wt% added iron.¹ Unchecked, it reduces profitability by forcing refin-
• Increased coke and hydrogen yields as iron catalyses dehydrogenation. • Increased SOx emissions, since iron behaves like an inverse SOx reduction additive, capturing hydrogen sulphide
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