Nov-2023

ReNewFine for renewable diesel and SAF: Results of a 20-year partnership in 100% HVO (ERTC 2023)

Ketjen, a wholly owned subsidiary of Albemarle, launched in January of this year from its headquarters in Houston, Texas. Our solutions support clean energy, fluid catalytic cracking, hydroprocessing, organometallics, and curatives. We partner with industry leaders to increase resilience through tailored, highly effective catalyst solutions.

JAAP BERGWERFF
Ketjen

Article Summary

ReNewFine for Renewable Diesel and SAF
For many years, Ketjen’s ReNewFine catalysts have enabled refiners to co-process renewable feedstocks in their existing hydroprocessing units. This year, our ReNewFine portfolio became commercially available for the first time for hydrotreated vegetable oil (HVO) processing for renewable diesel and sustainable aviation fuel (SAF) production.

The story of ReNewFine’s commercial availability for 100% HVO began 20 years ago when Neste asked us to help realise its technology to convert triglycerides into transportation fuels with custom catalysts.

This NExBTL process was fully implemented in 2005 when Ketjen started to supply HVO catalyst solutions for Neste’s NExBTL units. This technology has since helped Neste to become the world’s largest producer of renewable diesel and SAF from waste and residues.

During that period, the profitability of the NExBTL process was optimised by Ketjen’s ReNewFine catalysts and support. Neste was able to gradually increase the throughput of feedstocks to the NExBTL units, resulting in a more than 50% increase in renewable diesel and SAF produced from the installed assets.

Importantly, Neste was able to pivot the mix of triglyceride feedstocks from predominantly true vegetable oils to more than 90% waste and residue streams, such as used cooking oil and fish and animal fat.  From a technical perspective, management of the impurities in these waste and residue streams is key to preventing a negative impact on catalyst activity and stability.

Figure 1 shows the application of a sequence of ReNewFine HDO catalysts to the generation of a clean paraffin feed ready to be isomerised in the second stage. The top layers of the HDO reactor are devoted to capturing inorganic impurities such as P and Si. The main HDO catalyst delivers selective removal of oxygen. Finally, dedicated finishing catalysts are applied to convert N-compounds and unsaponifiables. In doing so, pressure drop issues can be avoided and an ideal cycle length can be reached, even when processing waste and residue streams.

This is illustrated by the process data from a commercial cycle of an HDO reactor presented in Figure 2. Operational stability over a cycle of more than four years is evidenced by a stable WABT and limited pressure drop throughout the cycle. The optimal catalyst loading depends on feed, process conditions, and objectives and requires a genuine collaboration between the unit operator and catalyst supplier.

The 100% HVO process delivers a truly drop-in solution with the capability to produce renewable diesel, meeting the most stringent specifications in terms of cloud and pour point.

The superior isomerisation activity of the hydroisomerisation catalysts and the ability of the HDO catalyst system to protect the catalyst and enable it to operate at its optimal performance is critical. Over the years, Neste has been able to make changes to the product slate from the process to meet the increasing demand for SAF. In 2024, the company will produce 1.5 MT of SAF from its units, a significant percentage of transportation fuels produced through the NExBTL process.

Through selective isomerisation, ReNew-Fine achieves exceptional cloud point reduction while minimising the production of naphtha via unwanted cracking reactions. By adjusting the operating T, the degree of isomerisation and, thereby, the degree of cloud point reduction and the formation of SAF can be tailored. The effect of operating T of the ReNewFine hydroisomerisation catalyst on cloud point reduction is illustrated by data from commercial operation in Figure 3.
The impressive cycle length of the hydroisomerisation catalyst can only be achieved by perfect control of the HDO process, minimising the number of contaminants that reach the hydroisomerisation catalyst.

The basis of this continuous improvement is a partnership between Neste as the process inventor and operator and Ketjen as the catalyst supplier delivering the required functionality.

With the advent of ReNewFine’s commercial availability, all Ketjen clients will now be able to apply ReNewFine catalyst technology for the production of renewable diesel and SAF via the 100% HVO route.

This will allow our customers to maximise the profitability of their operation, whether via maximising throughput, processing of more challenging raw materials, or maximising the yield of SAF.  

Summary
The challenges of the clean energy transition are complex, requiring equally complex solutions to chart the path forward. Just as we partnered with Neste to develop ReNewFine catalysts for 100% HVO, Ketjen will partner with our customers to help navigate seamlessly through these challenges.

This short article originally appeared in the 2023 ERTC Newspaper, which you can VIEW HERE