narTC 2025
Hydrocracking a wider variety of feedstocks to meet demand while reducing energy costs
rene gonzalez editor, ptq
cracking can improve the overall yield and quality of the output. This method leverages the carbon-rich content of both feedstocks to produce valuable liquid hydrocarbons and hydrogen, which can further reduce dependency on fossil fuels. These studies suggest that hydrocracking of pyrolysis oil is at the precipice of promising pathways for converting waste materials into high- value fuels and chemicals, but not without significant challenges. A few of these challenges include the high oxygen content of biomass-based feed- stocks, often in the form of organic acids, alcohols, and aldehydes. These compounds can create acidic environments that cor- rode hydrocracking reactors, pipelines, and other processing equipment. Acidic cor- rosion can lead to pitting, loss of material integrity, and critical component failures, especially when high temperatures and pressures exacerbate the effects. Pyoils and other biomass-based feed- stocks contain significant amounts of water. When processed at high temperatures, water can enhance hydrolytic reactions and lead to corrosion of carbon steel and even stainless steel components. Biomass feedstocks may include chlorine from bio- mass or residual salts. Chlorine and sulphur compounds can form hydrochloric and sul- phuric acids during processing, leading to severe corrosion. These impurities require feedstock pretreatment, such as washing or catalytic upgrading, to reduce corrosive agents prior to hydrocracking. Overlapping concerns The common denominator among the wider variety of unconventional feeds under con- sideration is their hydrogen intensity and improved energy efficiency. Catalyst poi- soning and fouling have always been a big concern with any type of hydroprocessing operation. Metal contaminants and par- ticulates in biomass feedstocks can poi- son hydrocracking catalysts, leading to inefficiencies. Some contaminants also deposit on reactor walls, creating hotspots and local- ised corrosion, requiring frequent catalyst regeneration or replacement and advanced filtration systems. In summary, it is antic- ipated that hydrocracking will provide promising pathways for sustainable fuel production and high-margin petrochemi- cal feedstocks. However, it is essential to address these bespoke challenges to ensure operational reliability and longevity.
Refinery hydrocracking projects are expected to grow significantly through 2025, with worldwide capacity projected to reach almost 15 million bpd. Several large-scale hydrocracking units are under development or planned, as refiners use these units to crack aromatic ring com- pounds into gasoline, diesel, and jet fuel. Other refiners are planning to leverage hydrocracking to produce petrochemi- cal feedstocks such as naphtha, increase opportunities for processing bio-based feedstocks to produce renewable diesel (RD) and sustainable aviation fuel (SAF), as well as process plastic waste-derived pyoils to polyolefins. The industry has a mandate to expand hydrocracking capabilities to capture mar- gin upcycles. The hydrocracking of mac- romolecular polyolefins (like polyethylene, polypropylene, and styrene) capable of monetising new feedstock sources, such as plastic waste to value-added chemicals, on a practical scale, will be discussed in PTQ throughout 2025 (see Figure 1 ). Catalyst trends Hydrocracking catalyst development is driven by evolving feedstock challenges, stricter environmental regulations, and the growing need for higher conversion efficiencies and quality products, such as F76 Naval Distillate Fuel, which meet MIL-DTL-16884 specifications (free of impurities like heavy metals and sulphur compounds that could harm engines). Against this backdrop, key trends in hydrocracking catalysts include advanced zeolites, bimetallic and multimetallic cata- lysts, feedstock flexibility, and integration of nanotechnology. Zeolites with tailored pore structures enhance selectivity for spe- cific product ranges (for example, maximis- ing middle distillates free of impurities like heavy metals and sulphur compounds). Additional efforts are focused on zeo- lites with improved hydrothermal stability to withstand high temperatures and feed- stock water content, such as with biomass. Zeolites like ZSM-5 and beta-zeolites can be modified to optimise performance under various process conditions. While bimetallic combinations (like Ni-Mo, Ni-W, and Co-Mo) are well established for hydrogenation activ- ity and sulphur removal, customised cata- lysts with tunable metal loadings are being developed to handle diverse feedstocks. Nanotechnology is used to create sup- ports with uniform pore size and high sur- face area, leading to improved catalyst dispersion and activity. Metal nanoparti-
Figure 1 Highly integrated refinery and petrochemical facilities typically include single or two-stage hydrocracking
cles are employed for their superior cata- lytic properties compared to bulk materials. A longer catalyst lifespan has always been an important objective, as it reduces cok- ing and metal fouling, for example, lead- ing to extended catalyst life and reduced downtime. In parallel, better regeneration methods are being implemented to restore catalyst activity effectively. Petrochemical integration Refineries are optimising hydrocracking units to produce naphtha and other feed- stocks for petrochemical processes, such as for ethylene crackers and aromatics production. For example, research around hydrocracking of macromolecular polyole- fins to accelerate the upcycling of plastic wastes to value-added fuels and chemicals on a practical scale is ongoing. However, the industry may face higher investment chal- lenges as sceptics argue that between now and 2050, plastics in landfills are expected to grow almost 2.5 times higher than plas- tics recycling. Digitalisation and optimisation Refineries are increasingly adopting AI, machine learning, and real-time moni- toring to optimise hydrocracking opera- tions, enhance catalyst performance, and minimise energy consumption. AI algo- rithms analyse real-time operational data to optimise critical variables like tempera- ture, pressure, and hydrogen-to-hydrocar- bon ratios, ensuring maximum yield and efficiency. Predictive models help identify optimal operating conditions for feedstocks with
varying properties, while machine learn- ing (ML) models monitor equipment health, such as reactors and compressors, to pre- dict failures or maintenance needs before they occur. AI models analyse the proper- ties of crude oil and other feedstocks to predict their performance in the hydro- cracking process, enabling better feed- stock blending and selection strategies. Additionally, AI-driven simulations predict the yield of desired products, such as die- sel, jet fuel, or naphtha, based on feed- stock and operating conditions. AI can also assist in designing new cata- lysts by simulating molecular interactions. AI models help refineries minimise energy consumption by identifying inefficiencies in heat exchangers and other systems. Integration with digital twin models allows real-time energy tracking and optimisation. Biomass and co-pyrolysis Hydrocracking of pyrolysis oil derived from plastic waste has been extensively stud- ied for its potential to produce high-value products, such as gasoline, diesel, and chemicals. A few notable insights from the hydrocracking of pyrolysis oils have ben- efited from innovations in reactor designs, like fluidised beds or conical spouted beds, improving scalability and efficiency. This allows for better conversion of mixed or contaminated waste plastics into usable hydrocarbons. Additionally, acid scaven- gers like calcium oxide can be used during processing to address issues such as chlo- rine content in the feedstock. Combining biomass with plastic waste in pyrolysis processes and subsequent hydro-
Contact: editor@petroleumtechnology.com
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