| American Fuel & Petrochemical Manufacturers

Question 7: What are your potential strategies to increase refrigeration system capacity and throughput in sulfuric acid alkylation units?

Several options are available to increase capacity and throughput in the refrigeration system of a DuPont STRATCO® effluent refrigerated alkylation unit. Depending on the specific limitation of the system – whether it be the capacity available from the refrigerant compressor, horsepower limitations of the refrigerant compressor driver, refrigerant condenser capacity or reactor tube bundle area, a specific solution may be tailored to help the refiner improve performance of the refrigeration system with minimal capital investment.

Question 6: What are your typical disposal options for solid phosphoric acid (SPA) catalyst from a catalytic polymerization unit? Are you employing any innovative methods?

Based on input from previous surveys and discussions with Honeywell UOP SPA customers, appropriate catalyst disposal methods are determined by the spent SPA catalyst’s classification, whether hazardous or non-hazardous. If hazardous, the options are hazardous landfill or incineration.

Question 5: Is the presence of pyrophoric compounds common in feed/effluent exchangers? What neutralization methods do you employ prior to exposing the equipment to the atmosphere?

In 2015, UOP led a Principles & Practices session on the topic of NHT (naphtha hydrotreater) and reforming unit feed/effluent exchanger fouling and cleaning.

Question 4: For the isomerization unit, what is your treatment for the streams containing high concentrations of hydrochloric acid (HCl) in the reactor emergency depressurization system?

Honeywell UOP does not include treatment of gas from the reactor effluent as it enters the flare header when using the emergency depressuring system in our Penex™ and Butamer™ process unit designs.

Question 3: What are your Best Practices for unloading solid phosphoric acid (SPA) catalyst from a catalytic polymerization unit, and what safety issues do they address?

There are two types of Honeywell UOP Cat Poly reactors: chamber and tubular. Each has different unloading concerns, and there are several different unloading options available for each.

Question 2: Iron is one of the most common contaminant metals seen on naphtha reforming catalyst. What is the source, what is the impact to yields and operation, and what can be done to mitigate these effects?

Naphtha feed-based iron is typically removed in the upstream hydrotreaters, but breakthrough of iron to the reformer can occur due to insufficient operating severity in the hydrotreater once the hydrotreater catalyst bed is saturated.

Question 1: How do you manage organic fluoride compounds in effluent and recycle streams in an HF alkylation unit? How do you detect upsets, and how are the impacts on downstream units mitigated?

Typically, organic fluorides are managed in the butane and propane effluent streams from an HF alkylation unit. Treatment of the isobutane recycle stream is not needed. The propane and butane products are typically treated in alumina treaters to remove the organic fluorides and then in KOH treaters to remove moisture (which is created in the alumina treaters) and any HF “slip”.

Question 57: How are you optimizing the use of wet gas scrubbers caustic use and SOx additives?

You can utilize a SOx additive in addition to a Wet Gas Scrubber system in order to reduce caustic consumption and minimize cost. Utilizing a SOx additive can be optimized by calculating the caustic savings + value of additional liquid sulfur produced - the cost of the Sox additive.

Question 56: Excluding nickel passivation. How does antimony use in the reactor riser impact the FCC operations and equipment?

Antimony functions by attaching to a fresh Nickel molecule in the FCC feed and preventing it from laying down on the surface of the catalyst. Efficiency of antimony in passivating Nickel and tendency to have side effects is highly dependent on the carrier and distribution method. Antimony can be water based or oil based, with oil-based antimony having a higher lay down efficiency (approx. 85% typical) as compared to water based (approx. 65%).

Question 55: With new challenges presented by the Refinery Sector and Maintenance Venting Rules oil circuits are taking longer to prepare for maintenance; what successes and challenges have you had in staging shutdown operations to allow for safe entry to the FCC reactor/regenerator section prior to clearing other sections of the unit?

With new challenges presented by the Refinery Sector and Maintenance Venting Rules oil circuits are taking longer to prepare for maintenance; what successes and challenges have you had in staging shutdown operations to allow for safe entry to the FCC reactor/regenerator section prior to clearing other sections of the unit?