Gasoline blending

1. Refining
Gasoline Blending
Optimization

2. Outline
• Gasoline Blending Overview
• Online Blend Controller & Optimization
• Benefits

3. Blending Overview

4. Regulatory Level
• Blend lineup and component selection
• Recipe handler with pacer
• Volume integrator
• Quality reports
• Good solutions available at DCS level

5. Evolution of Blending Advanced Control
• Manual systems
• First level control
• Current technology

6. Manual Blending
• Typical giveaway 0.35 octane numbers
• Can be reduced with reblends
• Lab sampling during blend
• Expert corrects recipe on the fly

7. Initial Quality Distribution
0
0.2
0.4
0.6
0.8
1
1.2
-1 -0.5 0 0.5 1 1.5 2
Octane giveaway
OverspecUnderspec
Target

8. After reblending
0
20
40
60
80
100
120
140
160
0 0 to .2 0 to 0.4 0.4 to 0.6 0.6 to 0.8 >0.8
Final octane giveaway

9. First Level Control
• Trim blend with online analyzers
• Simple PID loops

10. Example of First Level Control
RON
RVP

11. First Level Control
• Reduces giveaway
• Can hide an unprofitable operation

12. Opportunity Cost
Component Price Recipe 1 Recipe 2 ROAD RVP
A $4.60 0 17.8 74.05 4
B $13.50 0 0 86.45 4
C $9.50 0 66.3 85.76 13
D $26.88 23.8 0 101.75 0.5
E $27.58 0 0 102.5 0.5
F $0.00 4.5 5.9 97.3 66.74
G $2.50 61.7 0 76.5 16.45
H $27.50 10 10 115 16
I $16.16 0 0 93 12
Average Cost $/BBL $10.69 $9.87
Spread $0.82

13. Modern Blending
Inline
Blender
Optimizer
A
F
F
F
F
Inventory
Process Analyzers
Tank
or Pipeline

14. Why Blend Optimization?
• Eliminate reblends
• Reduce quality giveaway: $0.35/octane
barrel
• Make recipe changes consistent with
refinery drives - example: maximize low
cost components

15. What is a Blend Optimizer
• An integrated suite of control technologies
designed specifically to optimize on-line
performance of the blender
• An applications product, not a generic
software tool or algorithm
• The best control technologies are imbedded
directly into the application giving the
operator trouble-free operation

16. The Cost of Giveaway
• LP gives marginal values for limiting specs
• These values are conservative
• Zero giveaway after reblend may not be
“free” if achieved with expensive
components
• Currently, average giveaway cost for a
100,000 BPD refinery is $100,000/month

17. Blending Models
On-line properties predictor
Controller/Optimizer
Philosophy
Precise Recipe
Adjustment
Update Planning
Blend Values
Automatically
Capture Benefits
Elements of Blend Optimizer

18. Benefit Areas
• Reduced variance cuts giveaway costs in
half
• With online certification, blend target can
be precisely at specification
• System consistently enforces lowest cost
policy
• Up to date blending values for LP

19. Blend Optimization
Opportunity
• One year payout
• Meets today’s and tomorrow’s blend
challenges
• Maintain competitive market position
Only an on-line optimizer is able to
guarantee that the benefits are captured

20. Flowsheet
Planning
Spreadsheet
Operator Screen
review
Recipe
Limits
Product Values
TRANSFER
to DCS

21. Summary
• Blend Optimization Highly Profitable
• Technology battle-tested
• Payout < 1 year