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Jun-2015

Achieving advantages with 
state of the art FCC catalyst solutions

The drop in crude prices affects individual customers in different ways, as refiners re-optimise process and yield objectives based on the availability and cost of crude.

Christophe Chau and Rosann Schiller
Grace Catalysts Technologies

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Article Summary

In response, Grace is commercialising a slate of new FCC catalysts to provide solutions for refiner’s current needs. The new products will complement the products launched over the last two years that were focused on resid conversion and managing shale or tight oil feed stocks in the FCC.

A history of innovation
Grace has a history of providing value to its customers with new products through innovation. A recent example is the product innovation resulting from the rare-earth supply crisis in 2010. Eight new low- or no-rare-earth FCC catalysts and additives were commercialised, reducing the risk posed by limited rare-earth supply for most of our customers. The ACHIEVE® series (100, 200, 300, 400, 800) comprises state-of-the-art catalysts technologies designed to maximise refiner’s profitability. To maximise the value from their fluid catalytic cracking (FCC) units, refiners seek to increase processing of opportunity crudes as well as capture economic opportunities as crack spreads fluctuate. As refiners adjust their operating conditions and yield objectives, Grace’s newest FCC catalytic solutions will help them maximise profit and manage the uncertainties of increased opportunity crude processing.

The ACHIEVE series of FCC catalysts
In response to the tight oil revolution in the United States, Grace launched the first product in the series, ACHIEVE 400 FCC catalyst, addressing the octane debits that were being encountered by North American refiners. This breakthrough technology has delivered an economic uplift on the order of $3-7M/yr in multiple commercial applications due to the boost in slurry conversion, FCC naphtha octane, and butylene yield.

During this research and development program, five key catalytic functionalities were developed to provide the yield flexibility desired by refiners.
• Increase distillate yields with high diffusivity matrices
• Reduce dry gas with advanced metals traps
• Drive conversion with ultra-high activity zeolites
• Maximise resid processing with leading coke selectivity
• Boost refinery octane with dual-zeolite technology

Designing the best catalyst systems from these functionalities encompasses the Grace approach to customised FCC catalyst design. Every ACHIEVE formula contains high diffusivity matrices to maximise distillate yield from the bottom of the barrel and provide resistance to poisoning from unconventional metals. ACHIEVE catalyst can be formulated over a range of activity, rare-earth exchange, and isomerisation activities. Grace’s capability to modulate hydrogen transfer activity in our self-manufactured zeolites, affords each refiner the optimal LPG to gasoline ratio for their operation.

The individual ACHIEVE catalyst series are differentiated by the incorporation of varied functionality, specifically chosen to meet the desired yield and process objectives of the individual refiner. Inclusion of Grace’s latest generation of integral metals traps protects active components from deactivation while preserving coke selectivity and minimising dry gas production. Improvements in coke selectivity enable the refiner to maximise processing of resid or other opportunity feed stocks. Refiners wishing to drive to high conversion benefit from ultra-high activity zeolites.

Additionally, the dual-zeolite option delivers increased naphtha octane as well as increased LPG olefinicity: butylene, propylene, or both.

The following examples illustrate how the flexibility of the ACHIEVE catalyst family have been applied commercially to improve FCCU yield and profitability.

Commercial Case Studies
Maximising Conversion with ACHIEVE 100

When processing lighter feedstocks, insufficient catalytic activity requires that the catalyst circulation rate increase so that conversion, and thus the coke yield from the catalyst, increases to satisfy the FCC heat balance. If the FCCU cannot physically circulate enough catalyst, it will be necessary to either reduce the unit charge rate or the reaction severity to stay within the FCC catalyst circulation limit. Use of a high activity catalyst can counter the effects of low delta coke, but it is important to select a catalyst with the proper coke selectivity (coke to conversion relationship). ACHIEVE 100 catalysts are formulated with ultra-high activity zeolite to counter the effects of low delta coke, while delivering the proper coke. In commercial application, ACHIEVE 100 catalyst delivered enhanced activity over a competitive catalyst. At constant coke, the switch to ACHIEVE 100 catalyst resulted in higher activity, higher gasoline and lower bottoms and an economic uplift of ~$0.40/bbl (Table 1).

Maximising Fuels Yields with ACHIEVE 200
Grace has been highly successful incorporating both nickel and vanadium metals trapping into FCC catalyst, mitigating the negative impacts of the metals. Currently 65+% of our worldwide customers are taking advantage of these innovations in their catalyst formulations.

An example of excellent metals trapping performance is evident in ACHIEVE 200 catalyst system as shown in Figure 2. Refinery operating data after the reformulation to ACHIEVE 200 catalyst resulted in higher gasoline yields and lower hydrogen, delta coke and slurry yield. The superior metals tolerance of the ACHIEVE catalyst allowed the refiner to increase conversion without increasing catalyst addition rate. The changes in operating conditions and yields after moving to ACHIEVE catalyst are summarised in Table 2, and the increase in gasoline yield and drop in slurry resulted in a benefit of ~$0.70/bbl for the refinery.

Maximising refinery octane with ACHIEVE 400
A common challenge reported by refiners operating on unconventional feeds, such as shale or tight oil, is a loss of gasoline pool octane, caused by reduced volume of alkylation feedstock. ACHIEVE 400 catalyst is formulated with multiple zeolites with tailored acidity, to deliver an optimum level of butylenes to keep the alkylation unit full and maintain refinery pool octane. Incorporation of isomerisation activity into the catalyst particle itself results in a more desirable yield pattern than would be realised by use of a traditional octane boosting FCC additive. In addition, ACHIEVE 400 has been shown to increase the octane of FCC naphtha. In multiple commercial trials, ACHIEVE 400 is delivering incremental octane and butylene, worth on average $0.6/bbl.

Managing Unconventional Metals with ACHIEVE 800
A resid unit experienced deteriorating performance as a result of processing high carbon, high iron opportunity feedstock and experienced iron poisoning. The symptoms of iron poisoning include a loss of bottoms cracking, as feed particles are blocked from entering the catalyst particle, and a drop in conversion. Catalyst design can be optimised to resist the effects of contaminant iron (and calcium) found in many opportunity feedstocks. The high diffusivity matrices in ACHIEVE possess an optimum distribution of mesoporosity, maintaining performance because diffusion to active sites remains unhindered, even at high-contaminant metals loadings. Commercial data demonstrate an improvement in gasoline and distillate yield, and a reduction in both dry gas and bottoms yields due to improved coke selectivity. Using base case economics, the shift to ACHIEVE resulted in an annualised yield improvement of $10M over the base catalyst formulation.

Summary: ACHIEVE the advantage
Processing additional opportunity crudes as well as upgrading the bottom of the barrel into light cycle oil (LCO) and lighter products are two ways refiners can maximise the value from their FCCU. The ACHIEVE series (100, 200, 300, 400, 800) comprises state-of-the-art catalysts technologies that are in multiple commercial applications today. The new technologies are enabling refiners around the globe to capture opportunities in a dynamic market.


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