30079_47.pdf

CHAPTER 47

LIQUID FOSSIL FUELS

FROM PETROLEUM

Richard J. Reed

North American Manufacturing Company

Cleveland, Ohio

47.1 INTRODUCTION 15 17

47.2 FUEL OILS 15 17

47.2.1 Kerosene 15 19

47.2.2 Aviation Turbine Fuels 1525

47.2.3 Diesel Fuels

47.3 SHALE OILS 1528

47.4 OILS FROM TAR &ANDS 15 28

47.5 OIL-WATER EMULSIONS 15 28

15 26

47.2.4 Summary

15 28

47.1 INTRODUCTION

The major source of liquid fuels is crude petroleum; other sources are shale and tar sands. Synthetic

hydrocarbon fuels—gasoline and methanol—can be made from coal and natural gas. Ethanol, some

of which is used as an automotive fuel, is derived from vegetable matter.

Crude petroleum and refined products are a mix of a wide variety of hydrocarbons—aliphatics

(straight- or branched-chained paraffins and olefins), aromatics (closed rings, six carbons per ring

with alternate double bonds joining the ring carbons, with or without aliphatic side chains), and

naphthenic or cycloparaffins (closed single-bonded carbon rings, five to six carbons),

Very little crude petroleum is used in its natural state. Refining is required to yield marketable

products that are separated by distillation into fractions including a specific boiling range. Further

processing (such as cracking, reforming, and alkylation) alters molecular structure of some of the

hydrocarbons and enhances the yield and properties of the refined products.

Crude petroleum is the major source of liquid fuels in the United States now arid for the immediate

future. Although the oil embargo of 1973-1974 intensified development of facilities for extraction

of oil from shale and of hydrocarbon liquids from coal, the economics do not faVor early Commer-

cialization of these processes. Their development has been slowed by an apparently adequate supply

of crude oil. Tar sands are being processed in small amounts in Canada, but no commercial facility

exists in the United States. (See Table 47.1.)

Except for commercial propane and butane, fuels for heating and power generation are generally

heavier and less volatile than fuels used in transportation. The higher the "flash point," the less

hazardous is handling of the fuel. (Flash point is the minimum temperature at which the fuel oil will

catch fire if exposed to naked flame. Minimum flash points are stipulated by law for safe storage

and handling of various grades of oils.) See Table 44.4, Flammability Data for Liquid Fuels.

Properties of fuels reflect the characteristics of the crude. Paraffinic crudes have a high concen-

tration of straight-chain hydrocarbons, which may leave a wax residue with distillation. Aromatic

and naphthenic crudes have concentrations of ring hydrocarbons. Asphaltic crudes have a prepon-

derance of heavier ring hydrocarbons and leave a residue after distillation. (See Table 47.2.)

47.2 FUEL OILS

Liquid fuels in common use are broadly classified as follows:

1. Distillate fuel oils derived directly or indirectly from crude petroleum

For most of the information in this chapter, the author is deeply indebted to John W. Thomas, retired

Chief Mechanical Engineer of the Standard Oil Company (Ohio).

Mechanical Engineers' Handbook, 2nd ed., Edited by Myer Kutz.

Table 47.1 Principal Uses of Liquid Fuels

Heat and Power

Fuel oil

Space heating (residential, commercial, industrial)

Steam generation for electric power

Industrial process heating

Refinery and chemical feedstock

Supplemental space heating

Stationary power generation

Isolated residential space heating

Standby industrial process heating

Kerosene

Turbine fuel

Diesel fuel

Liquid propane0

Transportation

Jet fuel

Diesel fuel

Aviation turbines

Automotive engines

Marine engines

Truck engines

Automotive

Aviation

Limited automotive use

Gasoline

Liquid propane

and butane0

°See Chapter 46 on gaseous fossil fuels.

2. Residual fuel oils that result after crude petroleum is topped; or viscous residuums from

refining operations

3. Blended fuel oils, mixtures of the above

The distillate fuels have lower specific gravity and are less viscous than residual fuel oils. Petro-

leum refiners burn a varying mix of crude residue and distilled oils in their process heaters. The

changing gravity and viscosity require maximum oil preheat for atomization good enough to assure

complete combustion. Tables 47.5-47.8 describe oils in current use. Some terms used in those tables

are defined below.

Aniline point is the lowest Fahrenheit temperature at which an oil is completely miscible with an

equal volume of freshly distilled aniline.

API gravity is a scale of specific gravity for hydrocarbon mixtures referred to in "degrees API"

(for American Petroleum Institute). The relationships between API gravity, specific gravity, and den-

sity are:

Table 47.2 Ultimate Chemical Analyses of Various Crudes3 6

Crude

Petroleum

Source

Baku, USSR

California

Colombia,

South America

Kansas

Mexico

Oklahoma

Pennsylvania

Texas

West Virginia

% wt of

Specific Gravity

(at temperature, °F)

0.897

0.951 (at59°F)

86.5

86.4

85.62

H N O

12.0

Base

1.5

11.7 1.14

11.91 0.54

0.60

Naphthene

85.6

83.0

85.0

85.5

85.7

83.6

*See, also, Table 47.7.

12.4

11.0

0.37

4.30

0.76

0.912

0.97 (at 59°F)

Mixed

Naphthene

Mixed

Paraffin

Naphthene

Paraffin

1.7

12.9

14.2

11.0

0.862 (at 59°F)

0.91

0.897 (at 32°F)

2.61

0.70

12.9

3.6

Table 47.3 Some Properties of Liquid Fuels2

Light

Fuel

Oil

Heavy

Fuel

Oil

Coal

Tar

Fuel

Bituminous

Coal (for

Comparison)

Gaso-

line

Kero-

sene

Diesel

Fuel

Property

Analysis, % wt

Boiling range, °F

Flash point, °F

Gravity specific at 59°F

Heat value, net

cal/g

Btu/lb

Btu/US gal

Residue, % wt at 662°F

Viscosity, kinematic

Centistokes at 59°F

Centistokes at 212°F

85.5

14.4

86.3

13.6

86.3

12.7

86.2

12.3

86.2

11.8

90.0

6.0

1.2

2.5

0.4

392 up

149

1.1

80.0

5.5

1.5

0.1

104-365

-40

0.73

0.1

284-536

102

0.79

1.0

356 up

167

0.87

1.5

392 up

176

0.89

2.0

482 up

230

0.95

1.25

10,450

18,810

114,929

10,400

18,720

131,108

10,300

18,540

129,800

10,100

18,180

131,215

9,900

17,820

141,325

9,000

16,200

7,750

13,950

0.75

1.6

0.6

5.0

1.2

3.5

1,20 20

1,50 18

s^r60/60°F = ^fTk5

where °API is measured at 60°F (15.6°C).

sp gr 60/60°F = l^-

62.3

where lb/ft3 is measured at 60°F (15.6°C).

SSU (or SUS) is seconds, Saybolt Universal, a measure of kinematic viscosity determined by

measuring the time required for a specified quantity of the sample oil to flow by gravity through a

specified orifice at a specified temperature. For heavier, more viscous oils, a larger (Furol) orifice is

used, and the results are reported as SSF (seconds, Saybolt Furol).

kin vise in Centistokes = 0.226 X SSU - 195/SSU, for SSU 32-100

kin vise in centistokes - 0.220 x SSU - 135/SSU, for SSU > 100

kin vise in centistokes = 2.24 X SSF - 184/SSF, for SSF 25-40

kin vise in centistokes - 2.16 X SSF - 60/SSF, for SSF > 40

1 centistoke (cSt) = 0.000001 m2/sec

Unlike distillates, residual oils contain noticeable amounts of inorganic matter, ash content ranging

from 0.01% to 0.1%. Ash often contains vanadium, which causes serious corrosion in boilers and

heaters. (A common specification for refinery process heaters requires 50% nickel-50% chromium

alloy for tube supports and hangers when the vanadium exceeds 150 ppm.) V2O5 also lowers the

eutectic of many refractories, causing rapid disintegration. Crudes that often contain high vanadium

are

Venezuela, Bachaqoro 350 ppm

Iran

350-440 ppm

Alaska, North Slope 80 ppm

47.2.1 Kerosene

Kerosene is a refined petroleum distillate consisting of a homogeneous mixture of hydrocarbons. It

is used mainly in wick-fed illuminating lamps and kerosene burners. Oil for illumination and for

Table 47.4 Gravities and Related Properties of Liquid Petroleum Products

Typical Ranges for

Aviation

Diesel Turbine

Fuels Fuels Fuel Oils

Specific

Gravity

60°F/60°F

(15.6°C/

15.6°C)

Gross

Btu/

gaia

Gross

kcal/

liter3

Net

Btu/

gala

Net

kcal/

liter3

Specific

Heat®

40°F

Specific

Heat@

SOOT

Temperature

Correction

°API/°Fa

ft3 60°F

air/

gal

Ultimate

C02

Ib/

gal

H, wta

kg/

°API

#6 4

10*

#5 12

U 20

#2 30

1.076

1.060

1.044

1.029

1.014

1.000*

0.986

0.973

0.959

0.946

0.934

0.922

0.910

0.898

0.887

0.876

0.865

0.855

0.845

0.835

0.825

0.816

0.806

8.969

8.834

8.704

8.577

8.454

8.335"

8.219

8.106

7.996

7.889

7.785

7.683

7.585

7.488

7.394

7.303

7.213

7.126

7.041

6.958

6.887

6.798

6.720

1075

1059

1043

1028

1013

1000*

985.0

971.5

958.3

945.5

933.0

920.9

909.0

897.5

886.2

875.2

864.5

854.1

843.9

833.9

824.2

814.7

805.4

160,426

159,038

157,692

156,384

155,115

153,881

152,681

151,515

150,380

149,275

148,200

147,153

146,132

145,138

144,168

143,223

142,300

141,400

140,521

139,664

138,826

138,007

137,207

10,681

10,589

10,499

10,412

10,328

10,246

10,166

10,088

10,013

9,939

9,867

9,798

9,730

9,664

9,599

9,536

9.475

9,415

9,356

9,299

9,243

9,189

9,136

8.359

8.601

8.836

9.064

9.285

10.00

10.21

10.41

10.61

10.80

10.99

11.37

11.55

11.72

11.89

12.06

12.47

12.63

12.78

12.93

13.07

153,664

152,183

150.752

149,368

148,028

146,351

145,100

143,888

147,712

141,572

140,466

139,251

138,210

137,198

136,214

135,258

134,163

133,259

132,380

131,524

130,689

10,231

10,133

10,037

9,945

9,856

9,744

9,661

9,580

9,502

9,426

9,353

9,272

9,202

9,135

9,069

9,006

8,933

8,873

8,814

8,757

8,702

0.391

0.394

0.397

0.400

0.403

0.406

0.409

0.412

0.415

0.417

0.420

0.423

0.426

0.428

0.431

0.434

0.436

0.439

0.442

0.444

0.447

0.450

0.452

0.504

0.508

0.512

0.516

0.519

0.523

0.527

0.530

0.534

0.538

0.541

0.545

0.548

0.552

0.555

0.559

0.562

0.566

0.569

0.572

0.576

0.579

0.582

1581

0.045

18.0

17.6

17.1

16.7

16.4

16.1

15.8

15.5

15.2

14.9

14.7

14.5

14.3

14.0

13.8

13.6

13.4

13.3

13.1

13.0

12.8

1529

1513

1509

1494

1478

1463

1448

1433

1423

1409

1395

1381

1368

1360

1347

1334

1321

1309

0.048

0.050

0.051

0.052

0.054

0.056

0.058

0.060

0.061

0.063

0.065

0.067

0.069

0.072

0.074

0.076

0.079

0.082

0.085

0.088

ID JET A

r i jp5 i#i 38

(48) (47) t(48) (48) 40

JP4 42

X56) 44

aFor gravity measured at 60°F (15.6°C) only.

*Same as H2O.

Table 47.5 Heating Requirements for Products Derived from Petroleum3

Btu/galb to Heat from 32°F (0°C) to

Pumping Atomizing

Temperature Temperature Vapor

Commercial

Fuels

Specific Gravity at

60°F/60°F(15.6°C)

Distillation

Range, °F(°C)

Vapor Pressure,3

psia(mm Hg)

Latent Btu/galb

to Vaporize

No. 6 oil

No. 5 oil

No. 4 oil

No. 2 oil

Kerosene

Gasoline

Methanol

Butane

Propane

"At the atomizing temperature or 60°F, whichever is lower. Based on a sample with the lowest boiling point from column 3.

*To convert Btu/US gallon to kcal/liter, multiply by 0.666. To convert Btu/US gallon to Btu/lb, divide by 8.335 X sp gr, from column 2. To convert Btu/US gallon to kcal/

kg, divide by 15.00 X sp gr, from column 2.

Calculated for boiling at midpoint of distillation range, from column 3.

^Includes latent heat plus sensible heat of the vapor heated from boiling point to 60°F (15.6°C).

0.965

0.945

0.902

0.849

0.780

0.733

0.796

0.582

0.509

600-1000(300-500)

325-1000(150-500)

325- 750(150-400)

256- 481(160-285)

35- 300( 37-185)

148 (64)

31 (0)

-44 (-42)

0.054 (2.8)

0.004 (0.2)

0.232 (12)

0.019 (1)

0.039 (2)

0.135 (7)

4.62 (239)

31(1604)

124(6415)

764

749

737

743

750

772

3140

808

785

371

133

996

635

313

3619C

3559C

2725C

2704C

1303C

1215C

3400d

916d

963d

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