Catalysis 2024 Issue

Fossil oil fraction

Waste plastics oil

Figure 1 Speciation of neutral N-containing compounds as measured in a fossil oil fraction (left) and a waste plastics oil (right) via N-selective GCxGC, showing the absence of carbazoles and other refractory compounds in this waste plastics oil

Nitrogen-containing compounds Thirdly, as is the case of fossil feedstock hydroprocessing, and with renewable and recycled feedstocks, the pres- ence of nitrogen-containing compounds can negatively affect overall hydroprocessing catalyst system perfor- mance; hence, a catalyst load with proper hydrodenitro- genation (HDN) activity is required. To produce renewable diesel or sustainable aviation fuel (SAF) via the hydropro- cessed esters and fatty acids (HEFA) route, nitrogen must be removed to prevent deactivation of the downstream hydroisomerisation catalyst. Especially when animal fats are processed, the feedstock is rich in nitrogen, which is difficult to convert, as in the case of tertiary amides. To handle these large refractory molecules, a specific cat - alyst is required with high HDN and hydrogenation activ- ity, and excellent pore accessibility. On the other hand, in WPOs, the total nitrogen content can occasionally be high, typically consisting of easy, neutral species, with only negli- gible amounts of refractory compounds like carbazoles (see Figure 1 above). In summary, effective hydroprocessing of renewable and recycled feedstocks demands tailored catalyst formulations and loading configurations, informed by a comprehensive understanding of feedstock molecular composition and

reactivity, as well as catalyst functionalities. This requires extensive specific work in the lab and on the commer - cial units. Collaboration between process operators and catalyst suppliers, leveraging decades of experience, is essential. The proprietary ReNewFine catalyst solutions developed through a decade-long partnership between Ketjen and Neste, and applied using Ketjen’s proprietary ReNewSTAX catalyst loading strategy exemplify the suc- cess of this collaborative approach in producing renewable diesel and sustainable aviation fuel. A Victor Batarseh , Strategic Marketing Manager, FCC, victor.bataresh@grace.com , Stefan Brandt , FCC Market Development Director, Energy Transition, Stefan.brandt@ grace.com, W. R. Grace & Co. Grace’s catalyst technologies have been enhancing the prof- itability of FCCs for more than 80 years. Most of the efforts have been focused on catalyst technologies that unlock increased feedstock flexibility for refiners while maintaining a targeted yield slate for maximum profitability. Significant advancements in catalyst technology have optimised oper- ation while maximising high boiling point, aromatic, highly contaminated resid feedstocks. Grace’s approach (see Figure 1 below) to providing catalytic solutions involves a

Mesoporosity Hydrothermal stability Acidity Acid site density Na tolerance Content

Heat capacity Physical strength

Clay

Zeolite Y

Attrition resistance Bottoms cracking

Bottoms cracking

Binder

Mesoporosity Macroporosity Type Content

Ni tolerance V tolerance Fe tolerance

Metals tolerance

Matrix

FCC Catalyst Design

Mesoporosity Macroporosity Content

Mesoporosity Macroporosity Particle size distribution Sphericity Hydrothermal stability Attrition resistance

Hydrothermal stability Acidity Acid site density Content

Processing

Pentasil

Figure 1 FCC catalyst design factors

Catalysis 2024