ers face the same truth: a certain amount of phosphorus always finds its way into a hydroprocessing reactor. Over time, phosphorus build-up across catalyst beds can, and will, result in rapid pressure drop build. Once that pressure drop interrupts production, a complete shutdown of the reactor becomes neces- sary, along with replacement of affected catalyst layers. With renewable demand set to increase dramatically, maximising uptime should be among the foremost priorities for com- petitive refiners. Given the unpredicta- ble nature of feedstock quality, Topsoe decided to address that priority where the most progress could be made: the catalyst.
O K Na K Mg K
Al K P K K K
Ca K Fe K Mo L
Figure 3 A TK-3000 PhosTrap catalyst particle showing extensive pore system penetration of phosphorus Build-up to a better catalyst We decided to pursue a new solution. A fundamental understanding of both the crust formation mechanism and the crust itself, paired with our long-standing knowl- edge of catalyst design and manufacture, aided us in devising an effective answer for solving external build-up. Did you know a certain amount of phosphorus always finds its way into a hydroprocessing reactor? Its purpose would be: • To prevent phosphorus slip to the bulk catalyst • To inhibit pressure drop build from phos- phorus crust formation • To ensure longer catalyst cycle length, improving unit profitability and catalyst- value ratio mark that in the year 1990 the global oil demand for chemical feedstock repre- sented only 8% of total oil demand. Stage 2 - Forward Integration The 1990–2000 period marks a notice- able milestone since it consists precisely of the premises of the synergy between the refining and petrochemical sites, with battery limits partly integrated. The early stage of this synergy effect is reflected in an enhanced flexibility, which is the keyword of the nascent integration concept. Back then, diesel production was pushed against gasoline produc- tion, resulting in 15-25% of naphtha dedicated to chemical products mainly through steamcracking and aromatics production plants of still relatively mod- est capacities, with the exception of a couple of back-integration pioneers at that time. Such flexibility would not have been possible without reaching higher con- version levels owing to technological advances. Even so, the refining units of the plant remained mostly devoted to fuel production, from which side streams were spared to feed adjacent petrochem- icals units, which were conceived as a profitability booster for the plant.
Understanding the pressure drop mechanism
Topsoe has always relied upon fundamen- tal research as a starting point to overcom- ing production challenges. Throughout the process of analysing reaction kinetics, and the role they play in pressure drop, we uti- lised scanning electron microscope (SEM) imagery to discern why phosphorus build- up occurs in the use of conventional grad- ing products. Figure 1 demonstrates the issue: a tra- ditional catalyst particle, used to absorb and trap contaminants, fails to absorb phosphorus (shown as a bright green layer) into its pore system. Instead, the phospho- rus simply binds to the particle’s surface, forming a material similar to glass. The gradual build-up of this material glues the catalyst particles together, filling the inter- stitial void within the reactor and resulting in rapid pressure drop. Initial improvements to existing prod- ucts were partially successful: phosphorus uptake and penetration both increased, but the surface of the catalyst remained encrusted with phosphorus ( Figure 2 ). the evolution of the refining industry, from low chemicals conversion levels to much higher ones in recent years. This gradual evolution has been made possible by the ever more sophisticated technologies implemented over time. These technologies enabled a continu- ous adjustment as a response to market changes and regulations over investments. A series of steps allows for a transition towards chemicals even for short- and mid-term perspectives. Stage 1 - Simple Recovery Before the 90s, refining and petrochemi- cal were two distinctive industries made up of: • On the one hand, a conventional refinery set up to produce fuels • On the other, a petrochemical plant to produce major intermediates in petrochemicals At that time, when no deep conversion was required, there was no global vision, as the two value chains were evolving sepa- rately within their own sector, without shar- ing the full picture of the market demands. Refining naphtha was mainly dedicated to gasoline pool production, taking as a bench-
Figure 4 Phosphorus profile of TK-3000 PhosTrap
Producing for a brighter future As always, the technology you use mat- ters, but so does the technical exper- tise involved in maximising its value. TK-3000 PhosTrap – or indeed any simi- larly designed catalyst – can extend the life of your hydroprocessing catalysts, but you also need the right partner to ensure that you are getting the most out of a forward- thinking investment. When you are ready to take your pro- duction in an even smarter direction, get in touch with us. Topsoe is committed to helping producers succeed as enablers of a more sustainable future, and all it takes to get started is the will to progress – something we have always had in common with our partners.
Our efforts culminated in the success- ful development of TK-3000 PhosTrap. Applied as a guard in diesel and jet-fuel hydrotreating units processing renewable feedstocks, TK-3000 PhosTrap is a hydro- treating catalyst for use in fixed-bed HDO service, with a large pore structure uniquely tailored to maximise phosphorus pick-up. Figure 3 demonstrates its revolution- ary absorption capabilities: full penetra- tion into the pore system is clearly evident, with far greater pick-up towards the cen- tre of the particle, as well as a greater overall area beneath the curve, translat- ing to the superior overall capacity shown in Figure 4 . The first load to include this new catalyst was installed in 2020, with subsequent installation across a handful of units, and all installation instances have delivered exemplary performance, with phosphorus pick-up up to six times greater than that of conventional trap catalysts. Stage 3 - Scale and Portfolio Complexity After the third oil shock in 2008, the expensive oil era began. Higher conver- sion levels were required, as the balance between petroleum products and chem- icals kept on changing – and all the more so since heavy crude oil transformation is now of topical interest. The third integration stage, which occurred this past decade, focuses on the consolidation of partial integration and the building of ever larger plants. In total, 25-40% of a much larger naph- tha production was diverted to chemical products. The synergy between refin- ing and petrochemicals units was not yet fully optimised, but profitability greatly increased nonetheless thanks to techno- logical improvements. Technological improvements made it pos- sible to: • Benefit from economies of scale by build- ing larger plant capacities • Reduce drastically the energy costs associated with production • A more selective processing of available refinery streams to finished petrochemi- cals products.
TK-3000 PhosTrap ™ is a patent pending technology.
Stage 4 - Ultimate Crude Oil Conversion Finally, in 2020, the fourth stage of inte- gration started, which is the ultimate crude oil conversion into HVCs to capture further value, more attractive margins and reach robust growth prospects for chem- ical products. This ambitious but realistic goal is achievable through the combining of CTC technologies to transform a high proportion, in excess of 40%, of crude oils into chemicals. This implies significantly converting low- value residues to improve economics and to include flexibility to constantly match the market demand, thus ensuring maxi- mum returns, taking up the challenge of current global trends. While staged investments tailor-made to site characteristics and market objectives are certainly a valuable route for upgrading the profitability of existing sites by inte- grating new units, grassroots CTC com- plexes designed as a seamless system set a new benchmark for efficiency, flexibility to market and profitability. The first large- scale CTC complexes designed by a single refining and petrochemicals technologies provider were built at the end of the 2010– 2020 decade.
The CTC concept was born.
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