Product Blending & Optimization Considerations
Chapters 12 & 14
Updated: January 26, 2016
Copyright © 2016 John Jechura (jjechura@mines.edu)
Gases
Polymerization
Sulfur
Plant
Sat Gas
Plant
Gas
LPG
Alkylation
Polymerization
Naphtha
Isomerization
Light Naphtha
Fuel Gas
Butanes
Alkyl
Feed
Gas
Separation &
Stabilizer
Alkylate
Isomerate
Aviation
Gasoline
Automotive
Gasoline
Reformate
Naphtha
Hydrotreating
Heavy
Naphtha
Sulfur
LPG
Solvents
Naphtha
Reforming
Atmospheric
Distillation
Crude
Oil
Jet Fuels
Kerosene
Desalter
Distillate
Hydrocracking
AGO
LVGO
Vacuum
Distillation
Kerosene
Fluidized
Catalytic
Cracking
Gas Oil
Hydrotreating
Cat
Naphtha
Cat
Distillates
Solvents
Distillate
Hydrotreating
Treating &
Blending
Heating Oils
Diesel
Fuel Oil
HVGO
Cycle Oils
Residual
Fuel Oils
DAO
Solvent
Deasphalting
Visbreaking
Vacuum
Residuum
Coker
Naphtha
Heavy
Coker
Gas
Oil
SDA
Bottoms
Asphalts
Naphtha
Distillates
Fuel Oil
Bottoms
Lube Oil
Waxes
Coking
Lubricant
Greases
Solvent
Dewaxing
Waxes
Light Coker
Gas Oil
Coke
Updated: January 26, 2016
Copyright © 2016 John Jechura (jjechura@mines.edu)
2
Topics
• Blending
 Blending equations
 Specifications / targets
 Typical blend stock properties
• Optimization
 Economics & planning applications
 Optimization tools
• Linear programming
• Non-linear (geometric) programming
• Adjusting upstream operations to meet downstream targets
Updated: January 26, 2016
Copyright © 2016 John Jechura (jjechura@mines.edu)
3
Blending Equations
• Volume blending equations
 Specific gravity
 Olefins content (vol%)
∑V X
vX
∑=
∑V
i
i
(RVP )mix
1.25
 Aromatics content (vol%)
=
X mix
• Reid Vapor Pressure (RVP)
∑Vi (RVP )i
1.25
=
∑V
i
• Octane numbers – Simple, by volume
i
i
i
• Mass blending equations
 Sulfur content (wt% or ppm)
 Nitrogen content (wt% or ppm)
 Nickel & vanadium (ppm)
 Carbon residue (CCR, MCRT, …)
∑V γ X
i oi i
=
X
wX
∑=
mix
i i
∑V γ
i oi
Updated: January 26, 2016
Copyright © 2016 John Jechura (jjechura@mines.edu)
( RON )mix = ∑
Vi ( RON )i
( MON )mix = ∑
∑V
i
Vi ( MON )i
∑V
i
• Viscosity
log (log ( ν mix + ν c
V log (log ( ν
∑
)) =
∑V
i
i
+ 0.7 ) )
i
5
Non-Linear Octane Blending Formula
• Developed by Ethyl Corporation using a set of 75 & 135 blends
R = R + a1 RJ − R × J  + a2 ( O2 ) − O 2  + a3 ( A2 ) − A 2 




2
 ( A2 ) − A 2 

M = M + b1 MJ − M × J  + b2 ( O2 ) − O 2  + b3 


 100 


R+M
"Road" Octane =
75 blends 135 blends
2
a1
0.03224
0.03324
Sensitivity = J ≡ R − M
a2
0.00101
0.00085
Vi × X i
∑
Volume Average= X ≡
a3
0
0
∑Vi
b1
0.04450
0.04285
Petroleum Refinery Process Economics, 2nd ed. ,
by Robert E. Maples, PennWell Corp., 2000
Updated: January 26, 2016
Copyright © 2016 John Jechura (jjechura@mines.edu)
b2
b3
0.00081
-0.00645
0.00066
-0.00632
6
Typical Gasoline Blend Stock Properties
No.
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
Component
iC4
nC4
iC5
nC5
iC6
LSR gasoline (C5-180°F)
LSR gasoline isomerized once-through
HSR gasoline
Light hydrocrackate
Hydrocrackate, C5-C6
Hydrocrackate, C6-190°F
Hydrocrackate, 190-250°F
Heavy hydrocrackate
Coker gasoline
Light thermal gasoline
C6+ light thermal gasoline
FCC gasoline, 200-300°F
Hydrog. light FCC gasoline, C5+
Hydrog. C5-200°F FCC gasoline
Hydrog. light FCC gasoline, C6+
Hydrog. C5+ FCC gasoline
Hydrog. 300-400°F FCC gasoline
Reformate, 94 RON
Reformate, 98 RON
Reformate, 100 RON
Aromatic concentrate
Alkylate, C3=
Alkylate, C4=
Alkylate, C3=, C4=
Alkylate, C5=
Polymer
RVP, psi
71.0
52.0
19.4
14.7
6.4
11.1
13.5
1.0
12.9
15.5
3.9
1.7
1.1
3.6
9.9
1.1
1.4
13.9
14.1
5.0
13.1
0.5
2.8
2.2
3.2
1.1
5.7
4.6
5.0
1.0
8.7
(R+M)/2
92.5
92.5
92.0
72.0
78.8
64.0
82.1
60.5
82.6
87.4
74.6
77.3
67.5
63.7
76.8
72.5
84.6
82.1
86.5
80.2
85.9
85.8
89.2
92.3
94.1
100.5
89.1
96.6
93.8
89.3
90.5
MON
92.0
92.0
90.8
72.4
78.4
61.6
81.1
58.7
82.4
85.5
73.7
75.6
67.3
60.2
73.2
68.1
77.1
80.9
81.7
74.0
80.7
81.3
84.4
86.5
88.2
94.0
87.3
95.9
93.0
88.8
84.0
RON
93.0
93.0
93.2
71.5
79.2
66.4
83.0
62.3
82.8
89.2
75.5
79.0
67.6
67.2
80.3
76.8
92.1
83.2
91.2
86.3
91.0
90.2
94.0
98.0
100.0
107.0
90.8
97.3
94.5
89.7
96.9
°APl
78.6
80.4
48.2
79.0
86.4
85.0
55.5
49.0
57.2
74.0
55.1
49.5
51.5
58.1
49.3
54.8
48.5
45.8
43.1
41.2
70.3
59.5
Table 12.1 Blending Component Values for Gasoline Blending Streams
Petroleum Refining Technology & Economics – 5th Ed.
by James Gary, Glenn Handwerk, & Mark Kaiser, CRC Press, 2007
Updated: January 26, 2016
Copyright © 2016 John Jechura (jjechura@mines.edu)
7
Gasoline Blending Considerations
• What is available?
• What are you trying to make?
 Amounts
 Amount(s)
 Properties
 Properties
• Appropriate to determine product
properties
 Associated costs / values
• Volatility / RVP (maximum)
• Octane number (minimum)
• Drivability Index
• Distillation
o
T10 (minimum)
o
T50 (range)
o
T90 (maximum)
• Composition
o
Sulfur (maximum)
o
Benzene & total aromatics (maximums)
o
Olefins (maximum)
 Value
Updated: January 26, 2016
Copyright © 2016 John Jechura (jjechura@mines.edu)
8
Gasoline Blend Example – 2 Blend Stocks, 1 Spec
• Example, blending LSR only with Reformate
– one case 100 RON, other 94 RON
• To make Regular or Premium spec,
essentially diluting the Reformate
 94 RON Reformate alone cannot bring LSR
up to final spec
Updated: January 26, 2016
Copyright © 2016 John Jechura (jjechura@mines.edu)
9
Gasoline Blend Example – 3 Blend Stocks, 2 Specs
• Use 3 blend stocks to make regular gasoline (87 road octane) for both summer (9
psi RVP) & winter (15 psi RVP)
 R+M 

 = ( 92.5) vnC4 + ( 64.0 ) vLSR + ( 94.1) vRef
2


(RVP )
1.25
= ( 71.0 )
1.25
vnC4 + (11.1 )
1.25
vLSR + ( 3.2 )
1.25
vRef
1 = vnC4 + vLSR + vRef
Updated: January 26, 2016
Copyright © 2016 John Jechura (jjechura@mines.edu)
10
Diesel Blending Considerations
• Available blend stocks
• Specification of final product(s)
 Amounts
 Amount(s)
 Properties
 Properties
• Appropriate to determine product
properties
 Associated costs / values
• Cetane index (minimum)
• Flash Point (minimum)
• Distillation
o
T90 (minimum & maximum)
• Cold properties
o
Cloud point (minimum)
o
Pour point (minimum)
• Composition
o
Sulfur (maximum)
o
Aromaticity (maximum)
o
Carbon residue (maximum)
• Color
 Value
Updated: January 26, 2016
Copyright © 2016 John Jechura (jjechura@mines.edu)
11
Optimization for Economics & Planning
• What should be done rather than what can be done
• Optimization
 Combines models to…
• Describe operations
• Constraints to operations
 Economics added to define costs & benefits to all actions
 “Optimal” is best of the “feasible” possibilities
• Optimization models tend to be data-driven rather than mathematical model
driven.
Updated: January 26, 2016
Copyright © 2016 John Jechura (jjechura@mines.edu)
13
Economics & Planning Applications
• Crude oil evaluation
 Incremental value of an opportunity crude compared to base slate
 Take into account change in products produced
• Production planning
• Day-to-day operations optimization
• Product blending & pricing
 May have opportunity to separately purchase blend stocks
• Shutdown planning
 Multi time periods, must take into account changes in inventories
•
•
•
•
•
Multirefining supply & distribution
Yearly budgeting
Investment studies
Environmental studies
Technology evaluation
Updated: January 26, 2016
Copyright © 2016 John Jechura (jjechura@mines.edu)
14
Modeling Hierarchy
unit
operations
single
process
single
plant
model
multi-plant
model
refinery
model
multiple
processes
multi-refinery
model
Updated: January 26, 2016
Copyright © 2016 John Jechura (jjechura@mines.edu)
Process
Simulation
LP
Simulation
15
Unit Representations
Simple vector model
Feedstock
Butylene
Isobutane
Product
n-Butane
Pentane
Alkylate
"Alky Bottoms
Tar
Utilities
Steam, lb
Power, kWh
Cooling Water, M gal
Fuel, MMBtu
Delta-Base model
Yield
Vector
Feed
Hydrogen
C5-180
180-400
Kw
API
-1.0000
-1.2000
0.1271
0.0680
1.5110
0.1190
0.0096
Feed
1.0
-12.1
-22.0
1
Relative Activity
7.28
2.45
2.48
0.69
Base
Yield
Delta KW Delta API
-1.0
-1500
8.1
1.0
3.6
28.0
-5.5
11.0
10.9
1.2
20.0
4.0
1
1
0.5
• Relative activities calculated from actual properties – the
Kw & API rows are zero
1 × ( −22.0 ) + 1 × 20.0
API =
−
=
0.5
4.0
• For every unit of Butylene
consumed, must also consume the
relative amount of isobutane,
• Correct base yields to take into account actual properties
produce the shown amounts of
& relative activities
products, & use the shown amounts
of utilities
=
C5-180
Updated: January 26, 2016
Copyright © 2016 John Jechura (jjechura@mines.edu)
1 × 8.1 + 1 × 1.0 + 0.5 × 3.6
= 10.9
1
16
What is “Linear Programming”?
• Word “programming” used here in the
sense of “planning”
• For N independent variables (that can be
zero or positive) maximize
z= a01 x1 + a02 x2 +  + a0N xN
subject to M additional constraints (all bn
positive)
ai 1 x1 + ai 2 x2 +  + aiN xN ≤ bi
a j1 x1 + a j 2 x2 +  + a jN xN ≥ bj
ak 1 x1 + ak 2 x2 +  + akN xN =
bk
Updated: January 26, 2016
Copyright © 2016 John Jechura (jjechura@mines.edu)
 Terminology
 Objective Function – function z to be
maximized
 Feasible Vector – set of values x1, x2, …,
xN that satisfies all constraints
 Optimal Feasible Vector – feasible vector
that maximizes the objective function
• Solutions
 Will tend to be in the “corners” of where
the constraints meet
 May not have a solution because of
incompatible constraints or area
unbounded towards the optimum
17
Change Blending Equations to Fit Linear Form
• Volume blending equations
=
X mix
vi X i
∑=
∑V X
∑V
i
i
⇒
=
0
i
∑V ( X
i
i
− X mix )
• Mass blending equations
∑V γ X
i oi i
X
wX
=
∑=
mix
i i
∑V γ
i oi
⇒
0
=
Updated: January 26, 2016
Copyright © 2016 John Jechura (jjechura@mines.edu)
∑V  γ ( X − X )
i
oi
i
mix
18
Non-Linear Programming
• Non-linear blending rules can more closely match the physics of the problem
 Example: octane blending models
R = R + 0.03324 RJ − R ⋅ J  + 0.00085 ( O2 ) − O 2 


M = M + 0.04285 MJ − M ⋅ J  + 0.00066 ( O2 ) − O 2  − 6.32 × 10 −7 ( A2 ) − A 2 




• Guarantees of solutions are more tenuous
 Not necessarily at constraints
 Discontinuous feasible regions possible
• Types of optimization algorithms
 Local optimization
• Based on following gradients
o
Excel’s Solver based on GRG2
 Global optimization
• Randomly search overall region before switching to local optimization technique
o
Simulated annealing
Updated: January 26, 2016
Copyright © 2016 John Jechura (jjechura@mines.edu)
19
Gasoline Blending Considerations
• Available blend stocks
• Specification of final product(s)
 Amounts
 Amount(s)
 Properties
 Properties
• Appropriate to determine product
properties
 Associated costs / values
• Volatility / RVP (max)
• Octane number (min)
• Drivability Index
• Distillation
o
T10 (min)
o
T50 (range)
o
T90 (max)
• Composition
o
Sulfur (max)
o
Benzene & total aromatics (max)
o
Olefins (max)
 Value
Updated: January 26, 2016
Copyright © 2016 John Jechura (jjechura@mines.edu)
21
Gasoline Blending Example – All Into Regular
Raw M aterials
Properties for Blending Calculations
RON
Butane
Straight Run Naphtha
Isomerate
Reformate (High Octane)
Reformate (Low Benzene)
FCC Naphtha
Alkylate
MON
93.0
78.0
83.0
100.0
93.7
92.1
97.3
92.0
76.0
81.1
88.2
84.0
77.1
95.9
(R+M)/2
92.5
77
82.05
94.1
88.85
84.6
96.6
Cost & Availability
Butane
Straight Run Naphtha
Isomerate
Reformate (High Octane)
Reformate (Low Benzene)
FCC Naphtha
Alkylate
Products
Cost
($/gal)
0.85
2.05
2.20
2.80
2.75
2.60
2.75
0
0
0
0
0
0
0
Lower
Premium
Maximum
Available
30,000
35,000
0
60,000
0
70,000
40,000
RVP1.25
146.4
20.5
25.9
4.3
3.6
1.5
6.7
Aromatics
0.0
2.2
1.6
94.2
61.1
35.2
0.5
Olefins
0.0
0.9
0.1
0.6
1.0
32.6
0.2
Benzene
0.00
0.73
0.00
1.85
0.12
1.06
0.00
Premium
0
0
0
0
0
0
0
Upper
87
0.0
0.0
0.0
91
0.0
0.0
0.0
Octane
RVP
RVP1.25
Benzene
Octane
RVP
RVP1.25
Benzene
Regular
30,000
35,000
0
60,000
0
70,000
40,000
Minimum
Slack
30,000
35,000
0
60,000
0
70,000
40,000
Maximum
Slack
Minimum
Required
1
1
Maximum
Allowed
1,000,000
1
$1
$1
$0
$646,251
$557,251
$89,000
Lower Slack
234,999
457,000
5,741,488
210,750
-1
-3
25
0
Upper Slack
765,000
4,948,000
1,195,675
47,750
1
11
-14
0
Total
30,000
35,000
0
60,000
0
70,000
40,000
0
0
0
0
0
0
0
Price & Production Requirements
110
15.0
29.5
1.1
110
15.0
29.5
1.1
Product Calculations
Volumes & Properties
Produced
RON
MON
(R+M)/2
RVP
RVP1.25
Benzene
54
11.2
13.5
3.2
2.8
1.4
4.6
Usage
Minimum
Required
Lower & Upper Limits on Properties
Regular
RVP
Regular
Premium
Price
($/gal)
2.75
2.85
Cost & Revenue
Revenue ($)
Cost($)
Profit ($)
$646,250
$557,250
$89,000
Linear-Form Product Constraints
Regular
235,000
93.02
84.87
88.9
12.9
24.43
0.90
Premium
Updated: January 26, 2016
Copyright © 2016 John Jechura (jjechura@mines.edu)
0
83.24
81.59
82.4
28.0
64.46
0.48
Total
235,000
Regular
Premium
Volume
Vol*Octane
Vol*RVP1.25
Vol*Benzene
Volume
Vol*Octane
Vol*RVP1.25
Vol*Benzene
22
Gasoline Blending Example – Only Regular (Optimized)
Raw M aterials
Properties for Blending Calculations
RON
Butane
Straight Run Naphtha
Isomerate
Reformate (High Octane)
Reformate (Low Benzene)
FCC Naphtha
Alkylate
MON
93.0
78.0
83.0
100.0
93.7
92.1
97.3
92.0
76.0
81.1
88.2
84.0
77.1
95.9
(R+M)/2
92.5
77
82.05
94.1
88.85
84.6
96.6
Cost & Availability
Butane
Straight Run Naphtha
Isomerate
Reformate (High Octane)
Reformate (Low Benzene)
FCC Naphtha
Alkylate
Products
Cost
($/gal)
0.85
2.05
2.20
2.80
2.75
2.60
2.75
0
0
0
0
0
0
0
Lower
Premium
Maximum
Available
30,000
35,000
0
60,000
0
70,000
40,000
RVP1.25
146.4
20.5
25.9
4.3
3.6
1.5
6.7
Aromatics
0.0
2.2
1.6
94.2
61.1
35.2
0.5
Olefins
0.0
0.9
0.1
0.6
1.0
32.6
0.2
Benzene
0.00
0.73
0.00
1.85
0.12
1.06
0.00
Premium
0
0
0
0
0
0
1
Upper
87
0.0
0.0
0.0
91
0.0
0.0
0.0
Octane
RVP
RVP1.25
Benzene
Octane
RVP
RVP1.25
Benzene
Regular
30,000
35,000
0
12,628
0
70,000
39,999
Minimum
Slack
30,000
35,000
0
12,628
0
70,000
40,000
Maximum
Slack
Minimum
Required
1
1
Maximum
Allowed
1,000,000
1
$3
$2
$1
$515,976
$424,607
$91,369
Lower Slack
187,626
120,652
5,538,708
123,111
0
0
30
0
Upper Slack
812,373
4,194,760
0
83,278
0
19
0
1
Total
30,000
35,000
0
12,628
0
70,000
40,000
0
0
0
47,372
0
0
0
Price & Production Requirements
110
15.0
29.5
1.1
110
15.0
29.5
1.1
Product Calculations
Volumes & Properties
Produced
RON
MON
(R+M)/2
RVP
RVP1.25
Benzene
54
11.2
13.5
3.2
2.8
1.4
4.6
Usage
Minimum
Required
Lower & Upper Limits on Properties
Regular
RVP
Regular
Premium
Price
($/gal)
2.75
2.85
Cost & Revenue
Revenue ($)
Cost($)
Profit ($)
$515,973
$424,605
$91,368
Linear-Form Product Constraints
Regular
187,627
91.25
84.03
87.6
15.0
29.52
0.66
Premium
Updated: January 26, 2016
Copyright © 2016 John Jechura (jjechura@mines.edu)
1
91.75
90.25
91.0
15.0
29.52
0.19
Total
187,628
Regular
Premium
Volume
Vol*Octane
Vol*RVP1.25
Vol*Benzene
Volume
Vol*Octane
Vol*RVP1.25
Vol*Benzene
23
Gasoline Blending Example – Only Premium (Optimized)
Raw M aterials
Properties for Blending Calculations
RON
Butane
Straight Run Naphtha
Isomerate
Reformate (High Octane)
Reformate (Low Benzene)
FCC Naphtha
Alkylate
MON
93.0
78.0
83.0
100.0
93.7
92.1
97.3
92.0
76.0
81.1
88.2
84.0
77.1
95.9
(R+M)/2
92.5
77
82.05
94.1
88.85
84.6
96.6
Cost & Availability
Butane
Straight Run Naphtha
Isomerate
Reformate (High Octane)
Reformate (Low Benzene)
FCC Naphtha
Alkylate
Products
Cost
($/gal)
0.85
2.05
2.20
2.80
2.75
2.60
2.75
0
0
0
0
0
0
0
Lower
Premium
Maximum
Available
30,000
35,000
0
60,000
0
70,000
40,000
RVP1.25
146.4
20.5
25.9
4.3
3.6
1.5
6.7
Aromatics
0.0
2.2
1.6
94.2
61.1
35.2
0.5
Premium
30,000
17,433
0
60,000
0
32,959
40,000
Total
30,000
17,433
0
60,000
0
32,959
40,000
Olefins
0.0
0.9
0.1
0.6
1.0
32.6
0.2
Benzene
0.00
0.73
0.00
1.85
0.12
1.06
0.00
0
0
0
0
0
0
0
Upper
87
0.0
0.0
0.0
91
0.0
0.0
0.0
Octane
RVP
RVP1.25
Benzene
Octane
RVP
RVP1.25
Benzene
Regular
Minimum
Slack
30,000
17,433
0
60,000
0
32,959
40,000
Maximum
Slack
Minimum
Required
Maximum
Allowed
0
17,567
0
0
0
37,041
0
Price & Production Requirements
110
15.0
29.5
1.1
110
15.0
29.5
1.1
Product Calculations
Volumes & Properties
Regular
Premium
Price
($/gal)
2.75
2.85
1
1
1
1,000,000
$514,115
$424,930
$89,186
$514,118
$424,932
$89,186
Cost & Revenue
Revenue ($)
Cost($)
Profit ($)
$3
$2
$0
Linear-Form Product Constraints
Regular
Produced
RON
MON
(R+M)/2
RVP
RVP1.25
Benzene
54
11.2
13.5
3.2
2.8
1.4
4.6
Usage
Minimum
Required
Lower & Upper Limits on Properties
Regular
RVP
1
90.90
83.10
87.0
15.0
29.52
1.10
Premium
180,391
94.67
87.33
91.0
15.0
29.52
0.88
Updated: January 26, 2016
Copyright © 2016 John Jechura (jjechura@mines.edu)
Total
180,392
Regular
Premium
Volume
Vol*Octane
Vol*RVP1.25
Vol*Benzene
Volume
Vol*Octane
Vol*RVP1.25
Vol*Benzene
Lower Slack
0
0
30
1
180,390
0
5,325,125
158,662
Upper Slack
0
23
0
0
819,609
3,427,436
0
39,769
24
Gasoline Blending Example – Combined (Optimized)
Raw M aterials
Properties for Blending Calculations
RON
Butane
Straight Run Naphtha
Isomerate
Reformate (High Octane)
Reformate (Low Benzene)
FCC Naphtha
Alkylate
MON
93.0
78.0
83.0
100.0
93.7
92.1
97.3
92.0
76.0
81.1
88.2
84.0
77.1
95.9
(R+M)/2
92.5
77
82.05
94.1
88.85
84.6
96.6
Cost & Availability
Butane
Straight Run Naphtha
Isomerate
Reformate (High Octane)
Reformate (Low Benzene)
FCC Naphtha
Alkylate
Products
Cost
($/gal)
0.85
2.05
2.20
2.80
2.75
2.60
2.75
0
0
0
0
0
0
0
Lower
Premium
Maximum
Available
30,000
35,000
0
60,000
0
70,000
40,000
Aromatics
0.0
2.2
1.6
94.2
61.1
35.2
0.5
Regular
17,925
35,000
0
43,599
0
24,226
0
Premium
12,075
0
0
16,401
0
45,774
40,000
Total
30,000
35,000
0
60,000
0
70,000
40,000
Olefins
0.0
0.9
0.1
0.6
1.0
32.6
0.2
Benzene
0.00
0.73
0.00
1.85
0.12
1.06
0.00
Upper
87
0.0
0.0
0.0
91
0.0
0.0
0.0
Octane
RVP
RVP1.25
Benzene
Octane
RVP
RVP1.25
Benzene
Minimum
Slack
30,000
35,000
0
60,000
0
70,000
40,000
Maximum
Slack
Minimum
Required
1
1
Maximum
Allowed
1,000,000
1,000,000
$325,613
$285,199
$40,414
$657,675
$557,250
$100,425
0
0
0
0
0
0
0
Price & Production Requirements
110
15.0
29.5
1.1
110
15.0
29.5
1.1
Product Calculations
Volumes & Properties
Produced
RON
MON
(R+M)/2
RVP
RVP1.25
Benzene
RVP1.25
146.4
20.5
25.9
4.3
3.6
1.5
6.7
Usage
Minimum
Required
Lower & Upper Limits on Properties
Regular
54
11.2
13.5
3.2
2.8
1.4
4.6
RVP
Regular
Premium
Price
($/gal)
2.75
2.85
Cost & Revenue
Revenue ($)
Cost($)
Profit ($)
$332,063
$272,051
$60,011
Linear-Form Product Constraints
Regular
120,750
91.00
83.00
87.0
15.0
29.52
1.09
Premium
114,250
95.15
86.85
91.0
10.6
19.05
0.69
Updated: January 26, 2016
Copyright © 2016 John Jechura (jjechura@mines.edu)
Total
235,000
Regular
Premium
Volume
Vol*Octane
Vol*RVP1.25
Vol*Benzene
Volume
Vol*Octane
Vol*RVP1.25
Vol*Benzene
Lower Slack
120,749
0
3,564,521
131,888
114,249
0
2,176,967
78,862
Upper Slack
879,250
2,777,250
0
937
885,750
2,170,750
1,195,675
46,813
25
Gasoline Blending Example – Lower RVP & Benzene
Raw M aterials
Properties for Blending Calculations
RON
Butane
Straight Run Naphtha
Isomerate
Reformate (High Octane)
Reformate (Low Benzene)
FCC Naphtha
Alkylate
MON
93.0
78.0
83.0
100.0
93.7
92.1
97.3
92.0
76.0
81.1
88.2
84.0
77.1
95.9
(R+M)/2
92.5
77
82.05
94.1
88.85
84.6
96.6
Cost & Availability
Butane
Straight Run Naphtha
Isomerate
Reformate (High Octane)
Reformate (Low Benzene)
FCC Naphtha
Alkylate
Products
Cost
($/gal)
0.85
2.05
2.20
2.80
2.75
2.60
2.75
0
0
0
0
0
0
0
Lower
Premium
Maximum
Available
30,000
35,000
0
60,000
0
70,000
40,000
RVP1.25
146.4
20.5
25.9
4.3
3.6
1.5
6.7
Aromatics
0.0
2.2
1.6
94.2
61.1
35.2
0.5
Olefins
0.0
0.9
0.1
0.6
1.0
32.6
0.2
Benzene
0.00
0.73
0.00
1.85
0.12
1.06
0.00
Premium
0
0
0
0
0
0
0
Upper
87
0.0
0.0
0.0
91
0.0
0.0
0.0
Octane
RVP
RVP1.25
Benzene
Octane
RVP
RVP1.25
Benzene
Regular
8,187
28,305
0
0
0
60,824
40,000
Minimum
Slack
8,188
28,305
0
0
0
60,824
40,000
Maximum
Slack
21,812
6,695
0
60,000
0
9,176
0
Minimum
Required
1
1
Maximum
Allowed
1,000,000
1,000,000
$3
$3
$0
$377,621
$333,127
$44,493
Lower Slack
137,315
0
2,140,540
85,136
0
0
16
1
Upper Slack
862,684
3,158,261
0
0
999,999
19
0
0
Total
8,188
28,305
0
0
0
60,824
40,000
Price & Production Requirements
110
9.0
15.6
0.62
110
9.0
15.6
0.62
Product Calculations
Volumes & Properties
Produced
RON
MON
(R+M)/2
RVP
RVP1.25
Benzene
54
11.2
13.5
3.2
2.8
1.4
4.6
Usage
Minimum
Required
Lower & Upper Limits on Properties
Regular
RVP
Regular
Premium
Price
($/gal)
2.75
2.85
Cost & Revenue
Revenue ($)
Cost($)
Profit ($)
$377,618
$333,125
$44,493
Linear-Form Product Constraints
Regular
137,316
90.76
83.24
87.0
9.0
15.59
0.62
Premium
Updated: January 26, 2016
Copyright © 2016 John Jechura (jjechura@mines.edu)
1
95.03
86.97
91.0
9.0
15.59
0.62
Total
137,317
Regular
Premium
Volume
Vol*Octane
Vol*RVP1.25
Vol*Benzene
Volume
Vol*Octane
Vol*RVP1.25
Vol*Benzene
26
Gasoline Blending Example –Low Benzene Reformate
Raw M aterials
Properties for Blending Calculations
RON
Butane
Straight Run Naphtha
Isomerate
Reformate (High Octane)
Reformate (Low Benzene)
FCC Naphtha
Alkylate
MON
93.0
78.0
83.0
100.0
93.7
92.1
97.3
92.0
76.0
81.1
88.2
84.0
77.1
95.9
(R+M)/2
92.5
77
82.05
94.1
88.85
84.6
96.6
Cost & Availability
Butane
Straight Run Naphtha
Isomerate
Reformate (High Octane)
Reformate (Low Benzene)
FCC Naphtha
Alkylate
Products
Cost
($/gal)
0.85
2.05
2.20
2.80
2.75
2.60
2.75
0
0
0
0
0
0
0
Lower
Premium
Maximum
Available
30,000
35,000
0
0
65,400
70,000
40,000
Aromatics
0.0
2.2
1.6
94.2
61.1
35.2
0.5
Regular
13,552
35,000
0
0
53,656
70,000
35,854
Premium
1,355
0
0
0
11,744
0
4,146
Total
14,907
35,000
0
0
65,400
70,000
40,000
Olefins
0.0
0.9
0.1
0.6
1.0
32.6
0.2
Benzene
0.00
0.73
0.00
1.85
0.12
1.06
0.00
Minimum
Slack
14,907
35,000
0
0
65,400
70,000
40,000
Maximum
Slack
15,093
0
0
0
0
0
0
Minimum
Required
1
1
Maximum
Allowed
1,000,000
1,000,000
Upper
87
0.0
0.0
0.0
91
0.0
0.0
0.0
Octane
RVP
RVP1.25
Benzene
Octane
RVP
RVP1.25
Benzene
$49,147
$44,848
$4,299
$621,318
$556,271
$65,048
Price & Production Requirements
110
9.0
15.6
0.62
110
9.0
15.6
0.62
Product Calculations
Volumes & Properties
Produced
RON
MON
(R+M)/2
RVP
RVP1.25
Benzene
RVP1.25
146.4
20.5
25.9
4.3
3.6
1.5
6.7
Usage
Minimum
Required
Lower & Upper Limits on Properties
Regular
54
11.2
13.5
3.2
2.8
1.4
4.6
RVP
Regular
Premium
Price
($/gal)
2.75
2.85
Cost & Revenue
Revenue ($)
Cost($)
Profit ($)
$572,172
$511,423
$60,749
Linear-Form Product Constraints
Regular
208,062
91.10
82.90
87.0
9.0
15.59
0.51
Premium
17,244
94.51
87.49
91.0
9.0
15.59
0.08
Updated: January 26, 2016
Copyright © 2016 John Jechura (jjechura@mines.edu)
Total
225,307
Regular
Premium
Volume
Vol*Octane
Vol*RVP1.25
Vol*Benzene
Volume
Vol*Octane
Vol*RVP1.25
Vol*Benzene
Lower Slack
208,061
0
3,243,372
106,189
17,243
0
268,815
1,409
Upper Slack
791,938
4,785,436
0
22,810
982,756
327,645
0
9,282
27
Cutpoint Economics
• Adjust upstream cutpoints to meet needs in the downstream blending
 Heavy LSR…value as blending component
versus Reformer feed
 Heavy Naphtha…value as Reformer feed
versus kerosene blend stock
 Heavy Kerosene…value as kerosene blend
stock versus diesel blend stock
 Heavy Diesel…value as diesel blend stock
versus FCC feed
 Heavy Gas Oil…value as FCC feed versus
resid/asphalt production or coker feed
The refinery LP can determine the optimum
cut point for each of these given any set of constraints
Updated: January 26, 2016
Copyright © 2016 John Jechura (jjechura@mines.edu)
29
Cutpoints To Meet Operating Economies
TBP Cut Points (°F) for Various Crude Oil Fractions
Cut
IBP
EP
LSR
90
90
80
180
190
220
330
330
380
420
480
520
610
800
1050+
180
190
220
380
330
330
520
480
520
650
610
610
800
1050
Naphtha
Kerosene
Diesel
Gas Oil
VGO
Resid
Updated: January 26, 2016
Copyright © 2016 John Jechura (jjechura@mines.edu)
Processing Use
Min LSR cut
Normal LSR cut
Max LSR cut
Max reforming cut
Max jet fuel
Min reforming cut
Max kerosene cut
Max Jet A cut
Max gasoline
Max diesel cut
Max jet fuel cut
Min diesel cut
Cat cracker feed
Cat cracker feed
Coker feed, asphalt
30
Optimize FCC Gasoline Distillation
• Frame the analysis
 What is the value of the molecules in the stream
above?
 What is the value of the molecules in the stream
below?
 What upstream unit operations affect the stream
value?
 What downstream unit operations affect the
stream value?
 What unit specific operations affect the stream
value?
 What product blending constraints affect the
stream value?
Ref: http://www.refinerlink.com/blog/Truly_Optimize_FCC_Gasoline_Distillation
Updated: January 26, 2016
Copyright © 2016 John Jechura (jjechura@mines.edu)
31
Optimize FCC Gasoline Distillation
Value to the stream above?
Value to the stream below?
Upstream unit affects?
Downstream unit affects?
Unit specific affects?
Product blending constraints?
LCN
May have sub-optimal amount of olefins:
• Alkylation unit downstream have capacity for the
olefins?
• Type of alky unit? Sulfuric Alky can take more
C5= olefins; HF Alky limited by strength concerns
• Time of year? Alky economics better during
summer
When distillate more valuable than gasoline minimize
the LCN/HCN cut point to maximize distillate
production from HCN contributions
Degree of hydrotreating possible to give low sulfur
content in final product
Destination of LCN?
• Gasoline Hydrotreater & then to blend pool
• Selective Hydrogenation Unit & then to
Reformer
High olefin content will increase hydrogen
requirements in downstream hydrotreaters
Subtle constraints such as olefin content and octane
value will be influenced by a combination of riser and
distillation targets.
Cat-to-oil ratio affects product mix, thus distillation
strategies.
Usually routed to gasoline – need to olefins, sulfur,
and aromatics
HCN
When distillate more valuable than gasoline minimize
the LCN/HCN cut point to maximize distillate
production from HCN
Diesel prices higher than gasoline, minimize HCN end
point & still make diesel flash limit
If LCO is routed to a Hydrocracker HCN end point can
be adjusted to make jet flash limit.
HCN endpoint can also be used to optimize heavy fuel
oil blending when LCO is used as a cutter
Degree of hydrotreating possible to give low sulfur
content in final product
If routed to Gasoline Hydrotreater may reduce end
point to better make gasoline sulfur specs
If routed to Jet Hydrotreater then make-up hydrogen
constraints may limit end point
Fractionator draw constraints may be handled by
adjusting FCC reactor conditions & yields
When routing to gasoline, use HCN endpoint to adjust
gasoline sulfur, endpoint, and aromatics.
When routing to jet, use HCN IBP to meet jet flash &
endpoint to manage jet freeze & smoke point.
When routing to diesel, use IBP to manage diesel
flash
Ref: http://www.refinerlink.com/blog/Truly_Optimize_FCC_Gasoline_Distillation
Updated: January 26, 2016
Copyright © 2016 John Jechura (jjechura@mines.edu)
32
Gasoline Blending – Modify Upstream Operations
How much gasoline can be produced by blending Reformate+LSR with respect to
the Reformer’s severity?
Updated: January 26, 2016
Copyright © 2016 John Jechura (jjechura@mines.edu)
33
General Gasoline Blending Considerations
• Reduce RVP giveaway
 Blend nC4, not iC4.
• iC4 has higher vapor pressure than nC4
• iC4 has more value as alkylation feedstock
• Reduce Octane giveaway
 Setting constant reformer severity target – hydrogen & octane balance highly dynamic
constraints
 Blending low octane components to reduce octane giveaway – maybe there’s just too
much high octane blendstock?
http://www.refinerlink.com/blog/Redefining_Gasoline_RVP_Giveaway
http://www.refinerlink.com/blog/Top_3_Refinery_Octane_Blending_Mistakes/
Updated: January 26, 2016
Copyright © 2016 John Jechura (jjechura@mines.edu)
34
General Gasoline Blending Considerations
• Many blending problems require fixes to upstream operations
 RVP
• Poor depropanizer operation allowing propane into the butane pool?
• Proper splitting in Deisobutanizer & isostrippers?
 Octane
• Correct cut points between heavy naphtha & kerosene?
• Reduce reformer severity?
o
May not be possible if hydrogen needed.
• Batch operating reformer severity?
o
Would provide balance between octane enhancement & volume to blending
• Reducing reformer feed rates
• Selling high octane components
http://www.refinerlink.com/blog/Redefining_Gasoline_RVP_Giveaway
http://www.refinerlink.com/blog/Top_3_Refinery_Octane_Blending_Mistakes/
Updated: January 26, 2016
Copyright © 2016 John Jechura (jjechura@mines.edu)
35