Refinery Unit Optimization, TAR, and Risk Mitigation

Improve Performance and Delay Shutdown on Underperforming Units

FQE Chemicals is firmly positioned at the cutting edge of technology. Our expertise lies in providing tailored solutions for addressing and resolving unit-related challenges, guaranteeing that our customers can enhance flow performance and maximize margins.

Crude slates and changes of refinery feed over time yield deposits from solubility limitations of asphaltenes and precipitates over the lifetime between turnarounds. These deposits adversely affect operational efficiencies that reduce flow rates and heat transfer resulting in underperforming unit operations.

Even minimal amounts of deposits can result in significant heat transfer losses and flow rate reduction which cut into operation

efficiencies and run rates. A run rate reduction of as little as 1/3, compared to full capacity operation, translates into a 50% increase in fixed costs per ton of crude oil processed. Thus, cutting into margins and profits.

The FQE Chemicals product portfolio of chemical-based removal technologies maximize production by removing deposits and restoring operational performance.

High Intensity Injections Expedite TAR and Maintenance

Using FQE’s decades of experience and knowledge

Leverage our extensive expertise to recommend corrective chemical treatment options while the unit remains operational, aiming to restore flow rates, diminish pressure losses, and enhance heat transfer U-values. Employ high-intensity injections to reestablish optimal flow rates by efficiently eliminating fouling in towers and optimizing heat exchanger U-values.

Implement a circulation strategy using Solvent-H+ on isolated units, towers, vessels, and heat exchangers to eliminate foulant, precipitates, and scale deposits. This method supersedes the once-through approach, as it significantly expedites the process, saving valuable time without the need for diesel downgrade, since the existing hydrocarbon can be circulated effectively within the unit.

The circulation process can be closely monitored to establish a clear endpoint, ensuring precision in timing. Circulation of the extended network of piping and heat exchangers allows for in-place cleaning, delivering greater benefits as bundles are easier to disassemble. This results in fewer foulants left in the system for contractors to clean, conserving water and reducing the overall downtime for the unit to be operational again. All effluent can be reprocessed with zero waste generated.

Engineered Chemical Solutions to Remove Risk

Use risk management strategies to enhance vapor phase cleaning with LEL-Surface on existing steam lines to remove hazards and foulants before confined space entry. The strategy enables degassing and cleaning concurrently, as is tailored to the specific unit’s size and foulant’s hazard type; including pyrophoric iron deposits. Applying FQE’s Pyrophoric remediation chemistry will eliminate any pyrophoric iron sulfide, ensuring a safe and efficient process without the use of hazardous self-igniting oxidizers like potassium permanganate.

Finally, clear and clean strategy involves the simplest solution as it uses the refineries own equipment without the need for third-party personnel, their equipment, additional valves, hoses, and connections.

Solvent-H+: A patented dispersant and anti-foulant utilized for both online and offline cleaning of heavy hydrocarbon deposits in process equipment to significantly enhance lagging performance on critical path processes.

LEL-Surface: A patented technology which is a perfect balance of hard surface cleaning and LEL reduction for superior performance in vapor phase cleaning and degassing operations of entire units, vessels, towers, heat exchangers, tanks and other vessels.

Pyrophoric: Water-based chemical for safe and effective neutralization of iron sulfide deposits in hydrocarbon processing equipment, vessels, piping, filters, and tanks.

LEL-Vapor: Provides rapid absorption of vapor-state hydrocarbons via an innovative encapsulant formulation. This product reduces aromatic gases like benzene and other VOC/LEL producing hydrocarbons levels to zero in seconds.

Vacuum Tower Circulation

Vacuum towers face significant challenges due to the accumulation of dense asphaltenic hydrocarbons with API gravity below zero. The packing, trays, and bubble caps are particularly susceptible to these unwanted deposits. The issue is compounded by pyrophoric iron that is embedded within the asphaltenes intensifying the foulant problem. These contaminants persist and solidify over years of regular operation.

The innovative cleaning technology offers several advantages. It eliminates tough, heavy asphaltenic deposits within the tower without resorting to labor-intensive methods like jack hammering or water blasting. This speeds up the process and ensures smoother operations.

Other Examples:
Desalters, Heat Exchangers, Day Tanks, and Atmospheric Crude Tower

Sour Water Tanks

Sour water tanks are considered the highest hazard tank in the refinery. Wastewater is collected and contaminates are accumulated for over 10 years with 80% of the wastewater derived from three units – distillation, FCC and catalytic reforming. The multiple phases of oil, water, solids, and vapors make the situation more difficult for treatment strategies. The contaminates include hydrogen sulfide, ammonia, benzene hydrogen cyanide, other sulfides. Most worrisome is the pyrophoric iron sulfides.

FQE’s approach effectively pacifies and neutralizes the hazards within the tank itself. In contrast, the conventional outdated method involves batch-wise removal of hazardous solids to be treated with exothermic oxidizers. FQE’s strategy eliminates the exothermic reactions associated with potassium permanganate oxidation, thus removing the need for external batch treatment of sour water tanks. This enables a safer and faster in-situ treatment and cleaning process.


High Intensity Injection into Tower

Pressure losses forcing decision of unplanned turn around

Lower packed section of vacuum tower experiences problematic pressure losses negatively impacting processing conditions. The alternative is to force early unplanned turnaround and take unit out of service.

Added Solvent-H at ppm levels diluted in HVGO as cutter pulled from HVGO outlet stream to cascade over the problematic packing in the HVGO spray line system. The high intensity injection lasted 24-hours to provide sufficient contact time to foster dissolution of the heavy hydrocarbon deposits.

Prevented and held off unplanned turn around for 18-months which had a sizable impact on margins and refineries bottom line.



Vacuum Tower Turnaround Success

Clean in Place – No Equipment, No Contractors, No Waste

A planned outage for the vacuum tower includes the removal of asphaltenic solids and pyrophoric iron. The complex geometry of the tower’s packing, trays, and bubble caps tends to trap asphaltene deposits, causing blockages. Historically, the fouled packing has necessitated the use of jackhammers for removal. The process also involves confined space entry and extensive use of high-pressure water jets to eliminate fouling, which leads to a prolonged water consumption period.

Added Solvent-H+ into once through flush to the coker. Circulated coker gas oil with Solvent-H+ for 8-hours through VTB and heavy gas oil circuit including numerous heat exchangers.

Over 85% decrease of VTB on seal pan with only ½-inch of soft residue remaining. The packing came out easily this time. The entire procedure was handled internally by customer and lastly there was no waste generated as all materials were rerun

Maintenance Solutions

Empower activities to be safer, save time, and more effective

On a day-to-day basis, different maintenance operations and procedures are conducted (i.e., repair a value, change a filter, clean out a day tank). These operations can be time consuming and be a point of exposure and risk to the plant personnel performing the task. Procedures exist for shutdown operations that are typically – flush with hydrocarbon for a few hours, inject steam for an additional few hours and lastly add an oxidizer to attack the residual pyrophoric iron sulfides.

The process can be completed in a shorter amount of time, be more effective, and remove the hazard of using the unstable exothermic oxidizer.

  1. Use Solvent-H+ in the hydrocarbon step to circulate to be more effective at cleaning but also not downgrade a cutter stock like diesel or LCO
  2. While injecting steam, use LEL-Surface to remove the hydrocarbon embedded or trapped in the metallurgy
  3. Use a safe nature-based chemical, FQE’s Pyrophoric to pacify the iron sulfide without an exotherm or risk of a runaway reaction like permanganate oxidizer.


Empower steam injection with LEL-Surface
Degassing with water and LEL-Vapor
Degassing with Solvent-H or Solvent-H+ (not water)
Remove H2S vapors with FQE’s H2S Scavenger
Cleaning tools, valves, etc. to remove heavy deposits like asphaltenes
More effective, saves time and water consumption
Instantaneous reduction in VOCs/LELs, saves water, faster than diesel fill-and-drain
Drops LEL’s and decreases vapor pressure compared to alternatives (diesel)
Works in seconds, no heat required,
Dissolves in seconds with no heat required to remove deposits or free up frozen valves, blockages.

Typical Refinery Process 

Hover over individual units on our diagram to discover how our chemicals can help clean your refinery.

Contact our technical sales team today to learn more