Apr-2025

Enhancing refinery profitability through rigorous catalyst evaluation

The role of independent catalyst testing offers unbiased assessments crucial for unit performance and quality.

Tiago Vilela and Nattapong Pongboot
Avantium

Article Summary

In the complex world of petroleum refining, catalysts are integral to refining processes, enabling the conversion of crude oil into high-value products while significantly impacting operational efficiency and financial performance. Given the substantial costs associated with catalyst acquisition, typically ranging from $10 to $20 million, robust evaluation methodologies are essential for making informed decisions that align with production goals and market demands.¹

Independent testing plays a pivotal role in this evaluation landscape, offering unbiased assessments that are crucial for identifying catalyst performance issues and ensuring quality. By engaging external experts, refineries can uncover defects that internal teams may overlook, thereby optimising catalyst performance. Despite their importance, many refiners fall into common pitfalls when selecting catalysts, leading to suboptimal performance and reduced profitability.²

In summary, rigorous catalyst evaluation is paramount for enhancing refinery profitability. By implementing best practices in catalyst management, refiners can not only improve operational efficiency and reduce costs but also ensure compliance with evolving environmental standards and market expectations. The ongoing advancements in catalyst technologies further emphasise the need for independent testing.³

Rigorous catalyst evaluation
The choice of catalyst affects both daily operations and long-term planning. As catalysts play a vital role in refining processes, their selection directly influences the refinery’s production goals and overall financial performance. A well-executed catalyst evaluation ensures refineries operate with the most effective catalyst, maximising refining margins and profitability while minimising operational risks.

When selecting catalysts, refiners consider multiple factors, including expected performance, cost, guarantees, technical support, and their past experiences with potential suppliers. Key performance parameters are rigorously analysed, such as activity, yield selectivity, cycle life, deactivation rates, hydrogen consumption or production, and product properties.

To enhance evaluation accuracy, the process usually involves comparative catalyst testing in pilot plants under conditions that closely resemble commercial operations. This practice allows refiners to assess the economic implications and performance capabilities of different catalysts, ultimately selecting the one that best meets their operational needs.¹

Rigorous catalyst evaluation not only optimises performance but also significantly impacts the economics of refinery operations. By improving yield and efficiency, effective catalyst selection can lead to substantial cost savings and increased profitability.

Mistakes due to lack of testing are not uncommon, and some are very expensive. For example, in one US hydrocracker, switching from the usual feed to deasphalted oil increased the catalyst deactivation rate by six-fold. In another example, a new catalyst increased middle distillate yields in a diesel-oriented hydrocracker by 5.6 wt%. The difference was so dramatic that it debottlenecked the entire refinery.¹

Advantages
Independent catalyst testing is the best practice for rigorous catalyst selection. It provides an unbiased evaluation of performance, ensuring that refiners select the most effective catalysts for their units. The benefits include:
• Providing actual performance data, uncovering catalyst performance shortcomings. Side-by-side comparison fosters a more accurate benchmarking of the catalysts, providing reliable data on activity, hydrogen consumption, and the ability to process that feedstock, ultimately leading to improved performance.
• Refiners can make better-informed decisions by comparing multiple catalyst options based on objective performance metrics. A recent example for a diesel hydrotreating (DHT) unit catalyst selection showed that without testing, none of the catalysts proposed by suppliers would meet the target cycle length.
• Selecting the best-performing catalysts leads to improved product yields, lower utility consumption, and the ability to process lower-cost feedstocks, ultimately enhancing refinery profitability. Small changes in naphtha reforming C5+ yield can significantly impact refinery margins. For example, a 0.5% shift from C1-C4 to C5+ can result in an annual gain of €800,000. According to Pongboot et al, a performance gap between the best catalyst and an average one for a 54,000 bpd hydrocracker could be up to $20 MM/yr.³

Multiple catalyst options undergo rigorous testing under conditions similar to those of existing processes, culminating in an economic evaluation to determine the most advantageous catalyst system for the refinery.

Challenges  
Despite its many advantages, independent testing is not without challenges. Testing companies may lack comprehensive context regarding certain functionalities or intricate aspects of the evaluated catalysts:
• Industrial vs laboratory-scale fixed-bed reactor: Pilot plant testing aims to reproduce the industrial process in a shorter period of operation. Experimental aspects require consideration to ensure meaningful results and minimum biases between catalyst suppliers.^3,9
Since most pilot plants are once-through, the only way to simulate a two-stage hydrocracking process is to split the process into two parts:
- First-stage hydrocracking experiment: use fresh feed (Vacuum gasoil [VGO], Heavy coker gasoil [HCGO], deasphalted oil [DAO]) from the refinery with the target first stage per pass conversion.
- Second-stage hydrocracking experiment: use recycle feed (unconverted oil [UCO]) from the refinery with the target second stage per pass conversion and recycle feed rate.
Continuous catalytic reforming (CCR) is a moving bed process that is simulated in a fixed-bed pilot plant. In CCR operation, the catalyst is circulated between reaction and regeneration sections with a much slower space velocity compared to reactants. In a fixed-bed pilot plant simulation, there is no catalyst movement.
- Data normalisation is crucial for fair comparisons between catalysts, particularly when variations in product cuts could distort results. By correcting for interferences, such as the presence of inert gases and specific hydrocarbons in the product streams, evaluations can better reflect the true performance of catalysts.

It is important to select testing facilities with qualified testing methods and resulting data quality supported by catalyst experts with actual refinery experience.

Common pitfalls
An article by Vilela et al2 highlights several pitfalls in catalyst selection that should be considered in independent testing, including: