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Would you please share experiences of C4/C5 alkylation?
We are adding C5 alkylation to existing C4 alkylation.
It has a SAR (Sulfuric Acid Regeneration) unit.
Do they usually feed C4 and C5 mixture?
1. Is there any existing unit which is fed C4 and C5 separately?
C5 segregation cause any problem? Licensor says we consume less Sulfuric Acid than mixed feed.
2. With segregated C5 feed, spent acid strength will be 87wt%. Are there any critical reliability issues due to lower spent acid strength?
- reactor corrosion
- spent acid disposal and regeneration unit (SAR)
 
Answers
28/09/2009 A: keith bowers, B and B Consulting, kebowers47@gmail.com
Optimal spent acid strength for C5= alkylation (H2SO4) is much lower than for C3= and C4=, allowing that acid to be used as 'fresh acid' in the C5= reactor. Higher corrosion rates of mild steel with lower acid strength is of concern, and is highly dependent on local acid strength, NOT bulk acid conditions. You should consult with the process licensor for specific metallurgy requirements. Highly turbulent areas combined with low acid strength can cause extremely rapid metal loss and unexpected leaks in a matter of hours.