How can catalyst circulation rate and feed rate be related for promoting Naphthene dehydrogenation and paraffin dehydro cyclization reactions, desired reactions in CCR?

Crude Tank (Floating Double Deck Pontoon) is preparing to take crude oil (API29) for the first time. Is it safe to put crude directly in to the tank without Oxygen freeing? If water is first taken into the tank up to the floating level and than charge the crude, is it more safer?

The query is about UOP ATF Merox unit. Sometimes, due to processing of opportunity crude, ATF at outlet of ATF Merox is failing in RSH or colour, and not meeting ATF product spec. Therefore, has any refinery tried to recycle some of ATF Merox product along with Feed in order to improve inlet RSH so that ATF product spec can be met and instead of routing entire product to off-spec, partially ATF can be send as on-spec. The limitation here is minimum t'put through ATF Merox to be maintained, therefore, in order to improve product quality t’put cannot be reduced much. So, when we recycle product back to Feed line, minimum t’put can be maintained while reducing fresh feed, which will reduce total inlet RSH.

I would like to ask if any standard reporting systems contain tracking and metrics for any production companies that used catalysts with precious metals. It is a big business, and many financials flow in the process, which requires some tracking tool to measure the effectiveness of the company.

In Crude Distillation Unit CDU, we inject caustic soda (NaOH) for treating salts in crude oil (<= 20ppm ), but if the concentration of the salt in crude became too high (e.g 40ppm), desalter (desalting system) is required for that. The query is, if the desalter is out of service, what procedures are to be taken for treating salts? And what are the disadvantages of increasing the injection of caustic soda (NaOH)?

Crude unit is usually seeing water shots due to insufficient tank settling time, However, as soon as DCS operator notices increase in Desalter amps he first suspects high water carryover from Crude. Therefore, he reduces wash water make up to Desalter to reduce net incoming water to Desalter. As per our refinery Desalter control philosophy, Desalter water level is controlled by outgoing brine and wash water flow set point has been given as per requirement. So whenever there is water carryover with crude is occurring, manual intervention is required to control wash water make up. The query is, has any refinery tried to change the control philosophy of desalter to control desalter interface level with wash water addition rate and fixing the outgoing brine flow based on wash water flow requirement% basis. This is to reduce operator intervention during water shot upset.

I am currently looking after mechanical maintenance of Delayed Coker unit (DCU). We are witnessing frequent leakage issues in our plant due cyclic loading and unloading of Coke drums. Please suggest concrete solution either to resolve the issue or to mitigate the same and increase MTBF.

We have taken recently two shutdowns of DHDT unit due to HHPS overhead exchanger leak (CLPS HC to stripper vs HHPS overhead gases), leading to sudden increase in stripper overhead pressure. What can be possible reasons?

In catalytic reforming Process:
- increasing the initial boiling point leads to increasing in hydrogen production. Any Explanation ?
- How can we increase the purity of the hydrogen (recycle gas) ?
- What is the maximum allowable moisture (ppm) in the feed (Heavy Naphtha) ?

At our refinery we recently observed damage on the top of the radiant roof tubes of our VDU fired heater (2 parallel cabin radiant sections and 1 common convection section), clearly caused by long term operation at too high tube wall temperature. This is different from the issues we had in the past, where hotspots were mainly located on the bottom of the radiant tubes.

During the run we can't monitor this location with IR camera, thus the high temperatures could not be detected.

After restarting the unit the newly installed skin temperatures confirmed this area of the furnace is running at ca. 100 degC above the rest. Possible contributing factors are the presence of roof tiles just above the interested 8" and 10" tubes and the fact that the furnace was revamped to low-NOx burners 2 TARs ago.

Do you have any experience of high temperatures on the top side of the radiant tubes and possible mitigation measures / modifications to be carried out?

New constructed crude tank (Double Deck Pontoon Floating Roof) is going receive crude oil (29 API). What should be the status of the tank? Filled with water just up to floating level or keep the tank empty?

What is your experience with utilisation of internals in Riser? What are the expected benefits in delta pressure and yields?

At one of our gas processing plants, we are using hybrid amine solution MDEA for acid gas recovery. H2S 3% and CO2 1%. Our filter replacement frequency is very high, observed corrosion, sample analysis reflects, Iron count 14ppm. Other results are high acetates 13000 ppm in amine, PH reducing trend ...HSAS 1.5%. There is no any chemical injected on wellsite. What could be cause of corrosion /filter change out? What could be other source for acetates as production chemicals are not used on wellsite?

Is there a catalytic means to increase production from our hydrogen plant without a revamp or other significant capital outlay?

How can we improve the cold flow properties in the ULSD from our gasoil hydrotreater?

Should we expect some return on our original purchase cost if we send spent catalyst for metals recovery?

What level of SOx emissions from the FCC should we expect from current catalyst additives?

What steps can we take in our mild hydrocracking operations to improve FCC conversion performance?

What is the latest progress in FCC catalysis to boost bottoms upgrading?

What could be causing rapid catalyst deactivation in the hydrogenation of heavier fractions downstream of our steam cracker furnace?

For catalyst loss or mass balance, separator efficiency, general process throughput purposes; would hard data sets/measurements upstream in the FCC process be benificial or profitable versus relying on calculations for these same pieces of information?

We have two identical Claus trains in the SRU unit. Since the start up of the unit, 1st Claus reheater can not heat process stream up to required value. RIT achieved in the 1st train is approximately 10 degC lower.

What can be the possible causes and solutions?

FCC regenerator flue gas line refractory repeated failure is being experienced. Exact location of failure is at immediate downstream of the flue gas slide valve (Double disc type). Even after replacing the refractory in turnaround, hotspots developed early into unit operation. The dryout was carried out as per standard procedure and there were no thermal shocks due to sudden feed outage. Kindly suggest the reasons for this failure and if any modification in refractory type of design may help to avoid this in future.

Lean amine mechanical filters plug very often like 2 times per day. In our unit mechanical filters are located before lean amine coolers, but in other designs filters are located at the cold side. We also suspect that problem is due to corrosion in the regenerator overhead lines, but corrosion coupons show that corrosion speed is low.  

What can be the reason for such filter problem?

In our Delayed Coker unit Furnace, Plate type APH supplied by GEA Eco flex India Pvt Ltd is installed. Since last few months we are unable to increase Induced draft fan suction temperature as per our process requirement (To maintain acid dew point delta). Keeping in view of not increasing suction temperature we suspecting this furnace Combustion air APH may be leak and during furnace pigging/shutdown opportunity we thoroughly checked this APH but couldn’t find the leak If anyone having experience/expertise in above described matters, kindly share with us (like how to identify leak in furnace APH and what is standard practice follow to arrest the leak) Your valuable response will be appreciated!