FCC catalyst boosts bottoms upgrade
A combination of novel matrix technologies in a new FCC catalyst increased bottoms upgrading of residual feeds and improved profitability.
OLAF peter HARTMETZ and BERNHARD ZAHNBRECHER, Bayernoil
SABEETH SRIKANTHARAJAH and MARIA LUISA SARGENTI, BASF
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Since the beginning of 2020, most of the recognised analyst companies have been making predictions about the refining products market, first related to the impact of IMO 2020 and later to Covid-19. We have seen how refineries are more and more under pressure. It is not unexpected that they will continue to struggle with challenges that include more physical constraints, increasing costs of environmental regulations, changing and declining demand of products, and additional supply issues.
In particular, the combination of a narrowing crude market and weak demand is set to keep refining margins at historic lows over the coming months and FCC units will face more challenges to maximise their profits.1,2
What will be the threats for FCC operation? Probably there is not a unique answer to this question. The observed trends require the FCC unit to be able to deliver a favourable contribution to profitability and — in most units — to maximise its capacity to process residual feeds.
Implementation of the IMO regulations already resulted in drastically changing markets and created short-term opportunities requiring refiners to show maximum adaptability to capture value. Thus it has become imperative that refiners take advantage of the most effective options available to them. Resid feeds are known to be an example of opportunity crudes that can drive higher profitability for a refinery, given their low purchase cost. However, the processing of this type of crude requires flexible operation and catalyst to convert such crudes to lighter molecules and higher value products.3
More residue processing and optimised slurry oil production requires the catalyst to further upgrade bottoms and provide additional unit flexibility by overcoming and releasing operational constraints.
BASF has been targeting catalytic solutions to fulfill the need for resid FCC units to anticipate IMO challenges among others. The primary focus was, in one direction, maximisation of processing capacity for residual streams or, alternatively, optimisation of slurry oil production. Both routes would support FCC operation to achieve the target product slate in preparation for IMO implementation.
As a result, BASF has introduced the next generation of catalyst for moderate resid operations, Altrium, with a focus on three key functionalities:
- Higher meso-macro porosity for a better pore connectivity network to increase diffusion and conversion of large molecules
- Enhanced nickel passivation capabilities to minimise dry gas and coke yields
- Maximum light cycle oil (LCO) to bottoms conversion to generate more valuable products.
In addition, the benefits delivered by Altrium helped to release the unexpected additional pressures and operational disruptions caused by Covid-19.
Linking the benefits
Altrium is based on the combination of two technologies: AIM (Advanced Innovative Matrix) and IZY (Improved Zeolite-Y). These technologies have been linked to deliver high performance and value for moderate resid processing applications.
AIM consolidates several novel matrix technologies that are selectively incorporated into the catalyst design for a broad selection of performance targets and applications. It offers the flexibility to fine-tune the zeolite to matrix ratio in order to maximise conversion to transportation fuels.
With the introduction of AIM, BASF initiates a new generation of matrix families capable of delivering high performance through improved porosity which further enables the diffusion of large molecules to more and better distributed active sites.
Furthermore, the matrix and zeolite in Altrium are produced in a single manufacturing process step to make sure they are intimately dispersed and adjacent to each other. This in situ process enables maximum flexibility and control of matrix morphology, resulting in a catalyst with higher attrition resistance, no chloride, and the lowest sodium content available.
The manufacturing process allows for additional flexibility. Firstly, a catalyst microsphere is manufactured from kaolin clay and functional matrix raw materials. Then zeolite is grown within the microsphere. Nutrients for zeolite growth are provided by the microsphere itself, giving rise to the term in situ. Because the zeolite is grown directly on the microsphere, an epitaxial layer is formed, eliminating the need for a separate binder. By using the in situ process, higher levels of zeolite can be included in the catalyst. Additionally, the process leads to a more open pore architecture, allowing for improved metals tolerance.
Bayernoil Refinery GmbH is a refinery group of Varo Energy GmbH, Rosneft Deutschland GmbH, and Eni Deutschland GmbH. The company operates the largest refinery in the Bavarian region, ensuring security of supply in the region.
Production at Bayernoil has been running since 1964 on an area of about 300 ha southwest of the city of Neustadt. The refinery is supplied with crude oil from Trieste via the Transalpine Pipeline, producing propane and butane, refining gas, all types of gasoline, diesel, and light and heavy fuel oil.
Through continuous modernisation of the process plants and integration of the latest process technologies, it is one of the most productive refineries in the region with a Nelson Complexity Index of 8.1.
The FCC unit at Bayernoil Neustadt is a UOP stacked design with 30 000 b/d processing capacity, operating in deep partial burn using a catalyst from BASF (the “incumbent”). Resid feedstock with high metals and Concarbon is converted to valuable products.
Due to changes in the market environment, increasing the LCO output as well as gasoline and LPG volumes has become more attractive for refineries. Altrium was introduced to increase yields of transportation fuels and to improve the overall profitability of the operation.
To maximise the profitability of the refinery, the FCC catalyst is designed to meet the specific requirements of the unit by means of its metals tolerance, surface area, rare earth on zeolite, matrix type, and pore architecture. Firstly, the pore architecture requires optimisation to facilitate the diffusion of heavy feed molecules and to help improve heavy molecule (bottoms) cracking. Secondly, the relative zeolite and matrix content requires optimisation to prioritise conversion or distillate yield.4
Altrium FCC catalyst has been fine-tuned and customised to achieve new operating targets for Bayernoil. To that end, the catalyst’s design features include:
- A lower zeolite to matrix ratio (Z/M)
- Good metals tolerance, to maximise bottoms upgrading whilst maintaining low dry gas
- Ensuring that carbon on regenerated catalyst (CRC) is maintained at a low level to avoid disruption of the partial burn regime.
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