Q&A

(2018) Question 43: What are your economic and operational reliability implications of increasing cycles of concentration in your cooling tower?

Operationally, especially as production units are debottlenecked over time, increasing tower cycles could facilitate the ability to utilize existing Utilities Infrastructure. This minimizes the need to undergo a disruptive engineering and installation processes should unit capacity enhancement projects be identified.

(2018) Question 44: Describe your procedures for placing and operating the FCC in hot standby/safe park mode. What safety concerns do you consider and what safeguards should be in place?

If the air blower is not running, things you should consider are ensuring all ignition sources are shutdown, bypassed or isolated (ESP, torch oil, DFAH, CO Boiler). Verify all hydrocarbon sources to the reactor, riser and regenerator are closed (fresh feed, any recycles, torch oil, fuel gas purges, LCO quench, etc.) and all sources of air are not being injected (main air, plant instrument air, fluffing air, etc.).

(2018) Question 45: What are the safe and reliable options for rodding out plugged bleeders such as hydraulic ram pumps, packing gland / drill assemblies or tangential bleeders? How are these options used in a best practice for ensuring piping is hydrocarbon free and ready for maintenance?

Rod out tools or bleeder cleaners are safe and effective at clearing clogged drain, vent and instrument valves to be cleaned during normal operations. Most include some type of drill bit and local pressure gauge and are designed to handle high temperature and pressure applications.

(2017) 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”.

(2017) 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.

(2017) 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.

(2017) 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.

(2017) 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.

(2017) 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.

(2017) 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.

Find the answer to your technical question in AFPM's extensive Q&A database.

Q&A