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Recent Questions
Date  Replies
19/05/2017 Q: In VGO hydrotreater unit, cracked feed processed from coker unit which is mainly HCGO and HHCGO (Heavy Heavy coker gas oil). If HHCGO end point increased from 570 deg C to 600 degC, then how severe its impact on VGOHT operation and its catalyst performance?  
16/05/2017 Q: During the drying of fusel oil, what are the correct proportions and quantities of fusel oil and sodium chloride solution used for mixing? What amount of the filtered solution is distilled?  
16/05/2017 Q: in our C5/C6 Isomerization unit, the reactor effluent after feed/effluent heat exchanger has 43% liquid at 1040C. this effluent is being cooled to 400C using air finfan cooler and water trim cooler. Hydrogen rich gas is separated from liquid hydrocarbon in a separator at 18 kg/cm2 and used as recycle gas. We normally maintain H2/HC = 1.5 mole ratio.
We want to install a hot separator at the outlet of feed effluent exchanger to separate the condensed hydrocarbon and the remaining gases and uncondensed vapour will be further cooled in air fin fan cooler and water trim cooler. Liquid hydrocarbon from hot separator and cold separator will be mixed and sent to stabilizer to remove C1-C4 components.
1) I want to know whether this type of hot separator is feasible and did any refinery has this type of system.
2) How much will it affect recycle gas purity.
(1)
15/05/2017 Q: Our CDU overhead air cooled heeat exchanger is designed with 156 tubes and 3 passes. we have recently shutdown the unit to plug 32 leaked tubes:
- 20/52 tubes plugged in pass 1
- 12/52 tubes plugged in pass 2 .
We would like to estimate the effect of tubes plugging on the overhead ACHE performance by simulation (example wtih PRO II ).
How could we do that ?
(1)
14/05/2017 Q: We are using AXENS Catalyst RG-682 (Naphtha Reforming) and HR-538 (Naphtha Hydrotreating).
Now, my question is what is the actual life time of these two Catalyst? How many times it can possible to regenerate RG-682 & HR-538?
(5)
Recently Answered Questions
Date  Replies
14/05/2017 Q: We are using AXENS Catalyst RG-682 (Naphtha Reforming) and HR-538 (Naphtha Hydrotreating).
Now, my question is what is the actual life time of these two Catalyst? How many times it can possible to regenerate RG-682 & HR-538?
(5)
16/05/2017 Q: in our C5/C6 Isomerization unit, the reactor effluent after feed/effluent heat exchanger has 43% liquid at 1040C. this effluent is being cooled to 400C using air finfan cooler and water trim cooler. Hydrogen rich gas is separated from liquid hydrocarbon in a separator at 18 kg/cm2 and used as recycle gas. We normally maintain H2/HC = 1.5 mole ratio.
We want to install a hot separator at the outlet of feed effluent exchanger to separate the condensed hydrocarbon and the remaining gases and uncondensed vapour will be further cooled in air fin fan cooler and water trim cooler. Liquid hydrocarbon from hot separator and cold separator will be mixed and sent to stabilizer to remove C1-C4 components.
1) I want to know whether this type of hot separator is feasible and did any refinery has this type of system.
2) How much will it affect recycle gas purity.
(1)
15/05/2017 Q: Our CDU overhead air cooled heeat exchanger is designed with 156 tubes and 3 passes. we have recently shutdown the unit to plug 32 leaked tubes:
- 20/52 tubes plugged in pass 1
- 12/52 tubes plugged in pass 2 .
We would like to estimate the effect of tubes plugging on the overhead ACHE performance by simulation (example wtih PRO II ).
How could we do that ?
(1)
12/05/2017 Q: I am process engineer of Naphta Hydrotreating units in a Refinery with capacity of 350000 bbls/day. In this moment the refinery it has in storage tanks gasoline with higher weight percent in MTBE above 2 % weight. However this gasoline will be send to co-processing in VGO Hydrotreating unit (FCC Pretreatment) where according with our evaluation it is possible co-processing this naphta by dilution in the reactors taking in account because HDO reactions, will have more heat release, hydrogen consumption and water generating.
So we could hydrotreated this naphta in VGO hydrotreating unit, however the quantity of oxygen compounds like MTBE was about 20-40 ppm. This naphta is send to the naphta fractionator and will be separate in Light naphta (LVN) and heavy naphta (HVN), and the HVN stream is send to NHT unit. But the problem is, according with opinion of process engineer of NHT unit, the feedstock to NHT should not have oxygen compounds (0 ppm) in order to avoid fouling in the preheat train by gum formation, but the catalytic scheme installed in the reactor of NHT there are CoMo and according with my evaluation, after dilution of this naphta previous introduce to the NHT, the concentration of ppm in MTBE will be lower and i have read and studied, that in NHT units, the most of oxygen compounds are converted around 90 %, so in my oppinion would have not problems in send this feedstock to NHT unit.
My question is, does it exist a maximum concentration in ppm of oxygen compounds like MTBE in feedstock to naphta hydrotreating units? and which will be the main impacts in point of view catalytic and heat transer in the preheat train?
(2)
20/03/2017 Q: I am in charge of DHDT (produce 10ppm ULSD) catalyst performance monitoring, recently WABT was increased fast out of my expectation, meanwhile ULSD color was getting worse (DHDT has decolor reactor), observed cut point (T95) of feedstock SRLGO had a fluctuation in last few weeks, what is the possible cause of this abnormal WABT jump? (5)
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