Microsoft Word master thesis report fina doc

2.4.2. Influents / effluents scheme 
The following scheme represents simply what enters and what goes out the battery limit 
during normal operations.

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Figure B-2-4: Influents/effluents scheme for naphtha isomerisation unit in normal operations 
2.5. Intermittent operations 
2.5.1. Dryers regeneration 
Molecular sieves in dryers have to be regenerated on a regular time basis. It is consequently a 
cyclic regeneration. For this operation, the deisohexanizer distillate product is generally used 
as regenerant. After heating it flows on the sieve and it is recycled after the regenerant 
degasser where light components are flared and free water is drained and sent to oily water 
sewer. 
 
2.5.2. Influents / effluents scheme 
The following scheme represents simply what enters and what goes out the battery limit 
during dryers regeneration.
 
 
Figure B-2-5: Influents/effluents scheme for naphtha isomerisation unit during dryers 
regeneration 
Naphtha 
Isomerization Unit 
H
2
Chlorine 
Fuel gas 
Spent caustic 
Fugitive emissions 
Gas relieves 
FG / FO 
Combustion gas 
H
2
O 
Naphtha 
Isomerization 
Dryers 
Regeneration 
Fugitive emissions 
Free H
2
O
FG / FO 
Combustion gas 
Light components
Isomerate (recycled) 
Light
Naphthas 
Light and heavy Isomerates
Fresh caustic 
Isomerate product 

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2.6. Effluents characterization
In this part, each effluent (except products from the process and by-products) is the most 
precisely as possible characterized with data available.