Technology in Action
• Rejuvenation: The catalyst undergoes a treatment pro- cess to redisperse the active metals across the catalyst substrate, restoring active sites to the catalyst’s original fresh activity. The technology is relevant to both refining and re- refining and applicable to all manufacturers of both CoMo and NiMo catalysts. Potential applications include, but are not limited to, naphtha, kerosene, gasoline, ultra-low sul- phur diesel (ULSD), gasoil, and hydrocracker pretreaters. Excel rejuvenation technology has been in commercial service since 2015 at numerous refineries internationally, consistently meeting or surpassing expectations. Case study: High-pressure diesel hydrotreater It can be seen in Figure 1 how Excel rejuvenated catalysts brought significant sustainability, performance and, cost benefits when used in an ULSD unit in Europe. The unit processes a blend of light gas oil (LGO), vacuum gas oil (VGO), and coker distillate at high pressure (72 barg) Catalyst rejuvenation technology can support businesses in minimising waste and reducing emissions while maintaining stable and equivalent performance to fresh catalysts and severe liquid hourly space velocity (LHSV). Originally loaded with fresh catalysts, the business considered switching to rejuvenated catalysts for reduced lead times and lower fill costs. Evonik supplied an Excel rejuvenated high-activity NiMo catalyst from its inventory, accompanied by the proprietary CatGuard top bed grading and Durocel bed supports, pro - viding a full reactor solution. The rejuvenated catalyst per- formed equivalently to the previous cycle and at reduced expense. Scope 3 emissions were reduced due to using these catalysts, proving that performance does not need to be compromised in the journey to reduce emissions. Environmental impact and waste were further minimised by the fact that using rejuvenated catalysts, as opposed to fresh ones, reduces the number of catalysts that would typically end up in landfills. Case study: Low-pressure distillate hydrotreater Similar benefits were recorded at a low-pressure distillate hydrotreater in North America, spanning performance, cost, and environmental impact. The hydrotreating unit processes a blend of distillate cuts
Catalyst rejuvenation for greener hydroprocessing
The chemical industry enables so much of modern life, reaching 96% of all manufactured goods. However, its contribution to emissions cannot be denied, making sus- tainability an increasingly important part of a business’s strategy. Refiners face a balancing act to produce marketable products and maintain competitiveness in the face of increasingly stringent environmental regulations, external pressures, and surging energy costs. The challenge is to find economically efficient and sus - tainable operation methods without compromising per- formance or safety. Here, catalyst rejuvenation presents a solution. Marrying performance and cost savings, this tech- nology can help businesses minimise environmental impact and reduce waste. Rejuvenation technology Evonik’s proprietary Excel rejuvenation technology focuses on reusing a catalyst after its lifecycle. A type of sustain- able catalyst process, it recovers the full activity of spent hydrotreating catalysts, including the highly active Type II, to ensure their reuse in refining hydrotreating applications, with no loss to unit performance. The process involves the following steps: • Verification: Only the highest quality catalysts are eligible for Excel rejuvenation in reuse applications. They must be free from contaminants, meeting strict chemical and physi- cal specifications. • Regeneration: A simple oxidation reaction that removes carbon and sulphur. Evonik’s technology utilises a moving belt, minimising attrition, maximising yields, and maintain- ing physical properties to restore 65-85% of original activ- ity (depending on the original catalyst type).
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NiMo Excel
Alternative fresh catalyst
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Figure 1 The Excel rejuvenated catalysts performed equiv- alently to the fresh catalyst from the previous cycle
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Catalysis 2025
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