Dear all,
Feed incompatibility is normally a cause for fouling increase in the upper radiant section, due to asphaltene precipitation.
p-value is an analisys that is normally used to measure asphaltene precipitation tendency in other processes (like visbreaking, fueloil, etc).
Has anybody...
Dear all,
High content of solid particles in crude oil or Delayed Coker feed can cause accelerated fouling in the furnace.
Has anyone experience on how to measure solid particles concentration and particle size distribution in crude and/or vacuum residue? I have seen the use of laser difraction...
Dear all,
In one of our Delayed Coker units we suffer frequent re-foam events: sudden foaming during the steam stripping stage. These events sometimes happen when we turn to stripping to blowdown, so probably the main reason for these events is depressurizing of the coker drum. However, other...
Hello,
Silicon.based antifoams (PDMS) is routenily injected in the top of coker drums to reduce foam height. However, it has been claimed by some refiners that injecting the antifoam directly with the vacuum residue in the feed line, before entering in the drum, is more efective, with a fast...
"Sand-type" coke morphology
Typically, we process high asphaltene, high-MCR vacuum residues in our Delayed Coker, that produce a shot-coke morphology.
But in one of our Delayed Coker Units we have recently changed feedstock quality, to light (low-MCR, low ashaltenes). This light VR is producing...
"Sand-type" coke morphology
Typically, we process high asphaltene, high-MCR vacuum residues in our Delayed Coker, that produce a shot-coke morphology.
But in one of our Delayed Coker Units we have recently changed feedstock quality, to light (low-MCR, low ashaltenes). This light VR is producing...
Dear all,
Here are several different options to increase liquid production and reduce coke yield in residue coker units. One of the most widely used is try to operate coker drum at low pressure.
But, what are the possible options to reduce further the operating pressure in the coker drum?
Could...
Dear all,
Here are several different options to increase liquid production and reduce coke yield in residue coker units. One of the most widely used is try to operate coker drum at low pressure.
But, what are the possible options to reduce further the operating pressure in the coker drum?
Could...
Dear all,
Recently we have suffered some problems of Cupper Corrosion test failure in LPG. The LPG came from a caustic treatment for mercaptan sulphur removal. After caustic treatment, the LPG pass through a decanter (with NaOH/MEA solution) and sand filter, which are supposed to remove any...
Dear All,
We are having problems in an LPG Merox extraction unit of one of our refineries. A summary of the problema:
- Mercaptan content in LPG is too high compared with design: design 400 ppmw mercaptans in LPG and actual feed is 20000 ppmw mercaptans
- We do not see SH2 after the caustic...
There are mathematical correlations based on empyrical studies to predict the octane of many refinig products. Most of them use as input PIONA gas cromatographic analysis. So, GC licensors incorporate these correaltions in their software (normally these correlations are too general, they more or...
In one of our FCCU's we have problems to close heat balance due to the processing of a very hydrotreated feedstock. We have to use torch oil (LCO or fresh feed) to maintain regenerator at its minimum temperature.
We are evaluating the possibility of using other feedstock as torch oil. Has...
In one of our FCCU's we have problems to close heat balance due to the processing of a very hydrotreated feedstock. We have to use torch oil (LCO or fresh feed) to maintain regenerator at its minimum temperature.
We are evaluating the possibility of using other feedstock as torch oil. Has...
Dear all,
Some weeks ago, some cracks have appeared in the expander blades in one of our FCC units. The cracks appeared suddenly, from one month to another.
We have low fresh catalyst addition rate, so the turnover of the e-cat is very low. It has provoked the ageing of the inventory. We have...
Dear all,
Some weeks ago, some cracks have appeared in the expander blades in one of our FCC units. The cracks appeared suddenly, from one month to another.
We have low fresh catalyst addition rate, so the turnover of the e-cat is very low. It has provoked the ageing of the inventory. We have...
In one of our FCCU's we have an automatic pneumatic fresh catalyst injector to load the catalyst from the catalyst tank to the regenerator. Some weeks ago we start having problems with the fresh cat injection. After inspection of the pneumatic injector, we could see that a very hard deposit on...
In one of our FCCU's we have an automatic pneumatic fresh catalyst injector to load the catalyst from the catalyst tank to the regenerator. Some weeks ago we start having problems with the fresh cat injection. After inspection of the pneumatic injector, we could see that a very hard deposit on...
We have not experienced any kind of thermal cracking in the flue gas line, downstream the point where we inject the thermal shock steam.
We also inject 1 t/h of cooling steam just in the inlet point of the expander, as reccommended by the licensor of the turbine. It seems to be a huge ammount...
Dear 0707,
Thank you very much for your reply. We have checked TSS and it seems to be working properly. The aprticle size distribution at the bottom is OK.
We do not have a continuous water injection on bottom of the regenerator. However, I do not discard another uncontrolled water entry in...
Our current feed rate is around 60% vs the original design of the unit. However, we have experienced the same problem both at current feed rate (low feed rate, close to minimum technically possible) and at maximum capaciy
Best regards
