2 Petroleum Based Carbon CHARLES L. M A N T E L L
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447 Ryder Rd., Manhasset, N.Y., 11030
Petroleum-derived carbon is a huge industry, based on the heavy residual oils from vacuum fractionation or solvent extraction. These oils are feed stock for electrode coke or fuel for steam and power generation. Figure 1 shows the pyrolysis of residual hydrocarbons with severity of cracking. Table I shows transformations during coking. Table II shows commercial coke processes. Figure 2 shows a flowchart for delayed coking operations. Figure 3 shows interrelated petroleum coke quality variables. Table III shows typical analyses of petroleum coke. Figure 4 shows industrial utilization of pet coke. Table IV shows typical properties of calcinated petroleum coke. Figure 5 shows outlets for calcined petroleum coke. Table V gives analyses of calcined petroleum coke. A generalized flow sheet of electrode manufacture where petroleum coke is the preferred and almost exclusive raw material, is calcined, ground, mixed with binders, shaped, baked into amorphous forms and later graphitized, is shown in Figure 6. Petroleum coke is the life blood of the electro-process i n dustries. Coking is practiced by the petroleum industry to i m prove yields. The electro-process industries consume more than a quarter of our annual power production. Petroleum coke is preferred in its low volatile, low sulfur, low metal content for electrolytic anodes, electrodes for aluminum and magnesium, pastes for linings of fused salt electrolysis cells and self-baking units, electric furnace electrodes for copper, steel, cast iron melting; preparation of ferro alloys of wide variety, manufacture of calcium carbide and synthetic abrasives, refractories for blast furnaces, dies for continuous casting of metals; lumber and vessel linings, chemically resistant equip-
18
Deviney and O'Grady; Petroleum Derived Carbons ACS Symposium Series; American Chemical Society: Washington, DC, 1976.
2.
MANTELL
Petroleum Based Carbon OVER 2000»F
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D ε G R Ε ε 0 F C R A C Κ 1 Ν v>
S ε ν ε R I Τ Y
H 1 G H
1 Ν τ ε R M ε D I A Τ 1
ε
1800·· 2000T
THERMAL
HYDROGEN GAS THERMAL CARBON BLACK
DECOMPOSITION
400 8TU/CU FT GAS HEAVY AROMATIC 0 « S T « L I ATES PITCH COKE
HIGH TEMPERATURE COKING
700 BTU/CU.FT.OIL GAS
LOW 8TU
1600·I600 F
AROMATIC LIGHT OILS
OIL GAS
#
AROMATIC OIL GAS TAR
PRODUCTION
1300·* 1600· F
LAMPBLACK
HIGH BTU
1000 BTU/CUFT S HIGHER OIL GAS
OIL GAS
LIGHT OILS OIL GAS TAR
PRODUCTION
900·I200*F
REFINERY OAS
LOW
GASOLINE
TEMPERATURE
GAS OIL
COKING
#
REFINERY GAS GASOLINE GAS OIL
CRACKING
L 0 w 800·900 F
PETROLEUM COKE
THtNMAL
900·1000· F
19
THERMAL TAR
REFINERY GAS GASOLINE
VIS8REAKING
FUEL OIL
Figure 1. Pyrolysis of residual hydrocarbons with severity of cracking
TABLE I Transformations During Coking Product Characteristics Volatile matter, % Solubility in trichlorethylene, % Carbon-hydrogen ratio
Asphalt — 45 100 10-14
P i t c h -- S e m i pitch
A s p h a l t i c — Carboid coke coke
30-45
20-30
7-20
Less than 7
60-100
40-60
2-40
Less than 2
18-24
Greater than 24
Deviney and O'Grady; Petroleum Derived Carbons ACS Symposium Series; American Chemical Society: Washington, DC, 1976.
PETROLEUM DERIVED CARBONS
20
TABLEII Commercial Coking Processes Coking temperatures Type
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Method
Range, ° F
Type
Atmospheric still coker
Batch
Low
900-1000
Delayed coker
Semicontinuous
Low
900-935
Broad-oven coker
Batch
High
Greater than 1600
Contact coker
Continuous
Low
900-9C0
Fluid coker
Continuous
Low
900-950
6.700 LBS/HR
Ι 2 Ι · Α Ρ Ι MIO-CONTINENT 30% RE0UCED CRUDE |6% C0NRA0S0N CARBON DRUM 0VERHEA0
CAS COMPRESSOR
PRODUCT FUEL GAS 50 MM BTU/Hft [ACCUMULATOR C3-C4 PR00UCT 200 BS0
GASOLINE NO 2 FUEL OIL HEAVY FUEL OIL BLENDING
Figure 2.
Delayed coking operations
Deviney and O'Grady; Petroleum Derived Carbons ACS Symposium Series; American Chemical Society: Washington, DC, 1976.
Deviney and O'Grady; Petroleum Derived Carbons ACS Symposium Series; American Chemical Society: Washington, DC, 1976.
^Moisture-free basis. determinations made in accordance with Great Lakes Carbon Corp. analytical methods.
0.01
0.008
(35) 0.014
0.021 0.02
0.05
0.3
1.2
7.2
Fluid
West Coast
(34) 0.02 0.01
0.04
0.7
7.0
5.0
Fluid
Hawkins
(34) 0.17 0.06
(32) 0.0009
0.08
0.7
6.4
5.3
Fluid
Elk Basin
0.008
0.071
(34)
0.066
0.01
2.8
1.4
Fluid
South Louisiana
0.031
(32) 0.0006
0.01
0.37
0.21
13-18
1.8
Delayed
American Gilsonite Co.
0.0001
0.0004
(32)
0.11
0.14
0.10
9.2
7.8
0.0010
0.0284
0.040
0.0283
0.054
0.025
0.40
1.15
10.2
6.0
Delayed
Batch
2
(32) 0.0021 0.0006
0.0042
0.055
0.053
0.166
0.51
4.51
12.9
5.5
Delayed
(32) 0.0019 0.0003
0.0007
0.0060
0.021
0.012
0.11
1.08
12.8
6.0
Delayed
0.0031
0.0088
0.014
0.008
0.13
1.49
12.3
3.2
(32) 0.027
0.0002
Delayed
(32) 0.0038
0.0003
0.0086
0.020
0.0097
0.011
0.14
0.77
11.0
7.0
Delayed
(32)
0.011
0.0003
0.0041
0.0084
0.013
0.038
0.15
1.3
11.7
0.14
Delayed
(32)
l
Vanadium, Reference wt % 0.019
0.0003
0.0094
0.020
0.026
0.043
0.30
2.9
Titanium,
13.5
l
Nickel, wt %
0.81
i
Delayed
l
Silicon, Calcium, wt% wt %
Iron. wt%*
1
Ash. wt%
Sulfur, wt%l
Type
Pennsylvania2
California
2
2
Mid-Continent
Arkansas
2
Mid-Continent
2
2
Middle West
Ohio
2
Middle West
Source
Volatile matter, wt %1
Moisture, wt%
TABLE H I Typical Analyses of Petroleum Cokes
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to
Ο
r ι
5·
PETROLEUM DERIVED CARBONS
• CHARACTERIZATION FACTOR OEGREE Of REDUCTION FEEDSTOCK VARIABLES
CONRADSON CAROON SULFUR CONTENT • METALLIC CONSTITUENTS
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PETROLEUM COKE QUALITY
PROCESSING VARIABLES
TIME -TEMPERATURE - PRCSSURE CRACKING INTERRELATIONSHIPS • RECYCLE TO FEEOSTOCK RATIO COKE REMOVAL FACTORS BATCH, SEMI-CONTINUOUS, OR CONTINUOUS
ENGINEERING
VARIABLE
• CAPACITY ANO SIZE FACTORS •COKE REMOVAL EQUIPMENT COKE HANDLING, STORAGE, AND TRANSPORTATION
Figure 3. Interrelated petroleum-coke quality variables
LOW ASH FUEL
HIGH PURITY REACTANT
FERROUS METALLURGY
CALCINATION
• POWER PLANTS • DOMESTIC FUEL CEMENT KILNS
• CALCIUM CARBIDE • SILICON CARBIDE -MISCELLANEOUS CARBIDES -HIGH OENSITY FOUNORY COKE -BLAST FURNACE COKE CALCINED PETROLEUM COKE
Figure 4. Utilization of raw petroleum coke
Deviney and O'Grady; Petroleum Derived Carbons ACS Symposium Series; American Chemical Society: Washington, DC, 1976.
2.
MANTELL
23
Petroleum Based Carbon
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T A B L E IV Typical Properties of Petroleum Coke Used in Carbon and Graphite Manufacture Property
Raw coke
Coke calcined to 1300°C
15-100
15-100
Ash, %
0.1-1.0
0.2-1.5
Boron, ppm
0.1-0.5
0.2-0.7
25-500
25-500
Aluminum, ppm*
Calcium, ppm Fixed carbon, % Hydrogen, % Iron, ppm Manganese, ppm Magnesium, ppm Moisture, %
97-99
87-97
