Catalytic reforming is the heartbeat of gasoline octane and aromatics production in modern refineries. Operators tune dozens of interacting variables across reactors, heaters, separators, and recycle loops to achieve stable octane, strong hydrogen make, and long catalyst life. This guide summarizes the Top 10 Catalytic Reforming Operating Levers in Petroleum Refining to help both beginners and advanced practitioners structure daily decisions. Each lever is practical, measurable, and tied to common constraints such as feed quality, emissions, energy use, and reliability. Apply them systematically, verify with plant data, and align with economics to keep your reformer safe, profitable, and consistent year round.
#1 Feed window and cut point strategy
Start with the right naphtha window. Optimize initial and final boiling points to enrich naphthenes and paraffins that reform well, while keeping heavy endpoints that cause coke under control. Track PONA, naphthene content, and final boiling point in routine assays. Adjust splitter cut points seasonally to balance octane demand and hydrogen needs. Keep olefins and heavy aromatics limited because they drive gum and coke. Blend streams to maintain stable composition to the unit. A predictable feed reduces swings in reactor delta temperature, improves catalyst utilization, and simplifies advanced control. Good feed definition is the foundation for every other lever.
#2 Hydrotreating cleanliness and contaminant control
Protect the reformer by delivering ultra clean feed. Drive sulfur and nitrogen to very low limits using robust hydrotreating severity and fresh guard beds. Monitor metals, arsenic, and silicon because trace levels poison platinum sites. Control diolefins and color bodies that polymerize. Maintain feed dryness since water shifts chloride balance and acid site strength. Audit upstream unit upsets quickly, and circulate clean feed before returning to design severity. A well run hydrotreater extends cycle length, preserves activity, and keeps reactor temperature rise smooth. Cleanliness yields higher octane per degree of severity and reduces the frequency of regeneration decisions.
#3 Severity target and octane economics
Set severity based on clear octane and aromatics targets supported by economics. Use a severity index built from reactor average bed temperatures, pressure, and space velocity. Calibrate reformate RON and benzene response with validated analyzers, not lab snapshots alone. Map the value of hydrogen, aromatics, and octane loss against fuel pool requirements. Avoid chasing short term octane spikes that shorten catalyst life. When margins tighten, a small severity trim can save significant coke while protecting downstream isomerization and alkylation balances. Discipline around severity delivers predictable product quality, fewer heater adjustments, and steadier hydrogen for hydrotreaters across the site.
#4 Pressure and hydrogen partial pressure management
Lower pressure increases aromatics and octane, but it also accelerates coking. Find the sweet spot using reactor pressure, hydrogen to hydrocarbon ratio, and recycle purity together. Track hydrogen partial pressure, not only total pressure. Improve compressor performance, minimize pressure drops across reactors and exchangers, and keep control valves in their linear range. Use pressure trims alongside severity to manage cycle length. During feed quality deterioration, a small pressure increase can stabilize delta temperature and reduce hot spots. Smart pressure strategy maintains hydrogen make, preserves catalyst, and keeps the unit flexible when crude slates or product specs change.
#5 Space velocity and throughput optimization
Liquid hourly space velocity is a powerful lever linking throughput to conversion. Higher LHSV boosts rates but reduces residence time, often requiring higher temperature to hold octane. Build response curves that relate LHSV, severity, and RON to identify efficient operating envelopes. Coordinate with upstream and downstream units so reformer bottlenecks do not simply move elsewhere. When activity declines with time on stream, consider staged throughput reductions before major temperature steps. Use constraint based optimization to respect heater duty, reactor skin limits, and compressor head. Thoughtful LHSV control delivers more barrels when margins are strong and protects cycle life otherwise.
#6 Catalyst system health and chloride balance
Platinum and bimetal catalysts require careful management of acid and metal functions. Maintain chloride within the recommended window to keep acid sites active for isomerization and cyclization while preventing corrosion or excessive coke. Control water entering the unit, since it strips chloride and deactivates acidity. Track activity trends by bed, and watch for unexpected temperature bulges that indicate deactivation or maldistribution. For continuous regeneration units, monitor circulation rate, burn quality, and halide addition. For semi regenerative units, plan timely oxychlorination during regenerations. Healthy catalyst and balanced chloride unlock octane at lower severity and extend reliable operating windows.
#7 Temperature profile shaping and heater discipline
Reformer performance lives in the temperature profile. Target precise reactor inlet temperatures and manage interheater outlet temperatures to shape delta temperature across each bed. Avoid large inlet jumps that create local dehydrogenation spikes and hot spots. Calibrate skin thermocouples, verify radiant flux distribution, and keep burners tuned for even firing. Use weighted average bed temperature to coordinate APC moves and limit rate of change. When activity decays, prioritize incremental, measured steps rather than big pushes. A smooth profile stabilizes conversion, improves selectivity to aromatics, and minimizes coke formation. Heater discipline also protects tube integrity and energy efficiency.
#8 Coke formation control and regeneration strategy
Coke is inevitable, but its rate is controllable. Limit heavy endpoints, olefins, and aromatics precursors in the feed. Run hydrogen partial pressure and temperature profiles that discourage condensation and polymerization. Use online delta pressure, reactor delta temperature, and coke indicative analyzers to detect acceleration early. For continuous regeneration units, ensure steady catalyst circulation, complete carbon burn, and proper halogenation before return. For semi regenerative units, schedule regenerations based on severity trends, not only calendar time. After regeneration, ramp severity deliberately to avoid rapid recoking. Intentional coke management keeps octane consistent and preserves long term catalyst activity.
#9 Recycle gas purity and hydrogen system integration
Recycle gas purity determines true hydrogen partial pressure and selectivity. Maintain high hydrogen through good compressor health, low leaks, efficient separators, and proper purge to fuel. Use pressure swing adsorption or membrane systems to upgrade net hydrogen where justified. Limit methane and ethane dilution, and keep H2S and ammonia near zero to protect catalyst. Dry recycle gas prevents chloride loss and corrosion. Coordinate hydrogen supply with hydrotreating, hydrocracking, and isomerization to avoid site wide swings. When hydrogen value rises, retune severity and pressure accordingly. Strong recycle quality lifts octane, reduces coke, and stabilizes reactor temperature profiles.
#10 Advanced control, analytics, and reliability practices
Layer robust control on top of sound chemistry. Use model predictive control to coordinate heater duty, reactor temperatures, pressure, and LHSV against octane and benzene inferentials. Validate online analyzers with periodic cross checks and statistical monitoring. Employ soft sensors for RON, hydrogen make, and aromatics distribution to detect drift quickly. Track catalyst health KPIs such as activity index, chloride balance, and delta temperature per bed. Maintain exchanger cleanliness and correct maldistribution with periodic surveys. Tie everything to an economic optimizer that weighs octane, hydrogen, energy, and catalyst life. Reliable control turns good reforming science into sustainable profit.