Petroleum Biomarkers for Downstream

and Environmental Applications

C. S. Hsu

Future Fuels InstituteFlorida State University

242nd ACS National MeetingAugust 28 – September 1, 2011

Denver, Colorado

Differences in upstream and downstream analytical focuses

• Samples are different :

• Upstream – source rocks and oils from wells (localized).

mostly in native states, molecules stay intact (with possible

“contamination” from production chemicals)

• Downstream –blended crude oils from refineries. molecules

most likely altered in upgrading process streams and products.

• Bulk analyses and molecular speciation emphasis are different.

• Upstream:

Bulk analysis – TOC, isotope ratio, vitrinite reflectance, etc.

Molecular speciation - isomer specific for critical molecules

of geological significance.

• Downstream (also exploitation geochemistry in upstream):

Bulk analysis - SimDist, total sulfur, API gravity, etc.

Molecular speciation - molecules grouped into compound

types and carbon numbers. Unknown identification in

processes and products.

• retain basic carbon skeleton of biological origins.

• useful molecules for exploration/production in upstream.

• provide information on source, age, maturity and alteration.

• used for oil-oil and oil-source rock correlation.

• rarely applied in downstream processes

• used as source identification of petroleum-related pollution

Characteristics of petroleum biomarkers

Typical biomarkers and their origins

171816

1514131211

1098

7

65

4

19 20

21 2223 24

25262728293031323334

35363738

39 40

pristane phytane cyclic biomarkers

● isoprenoid hydrocarbons

Typical biomarker distributions in crude oils

20 30 40 50 60 70 80 90

27

28

29

28

29

30

31

32

33

34

35

Ts

Tm

23

24

2526

28

2930

222120

19

20

21

Normal Steranes

Diasteranes

Homohopanes

Hopanes

Tricyclic Terpanes

m/z 191 ion chromatogram

m/z 217 ion chromatogram

R

R R

191

217

259

hopanes steranes diasteranes

R

R R

191

217

259

hopanes steranes diasteranes

Hopanes and steranes provide most geochemical information

(Characteristic ions of:

Monoaromatic steranes at 253 Da

Triaromatic steranes at 231 Da)

Steranes resolved by GC/MS/MS

C26

C27

C28

C29

C30

M+ 368

M+ 372

M+ 386

M+ 400

M+ 414

A

B

C

D E

F

G

H

Hsu, C. S. Analytical Advances for Hydrocarbon Research, Chapter 9,

Kluwer Academic/Plenum Publishers, 2003.

G. H. Isaksen, Oil & Gas J., 3/18/91; pp. 130.

Gulf of Suez, Egypt; Miocene

Kupferschiefer, North Sea; Permian

Hopane / Sterane

Umiat Mt. Alaska; MesozoicParis Basin; Toarcian

North Sea; KimmeridgianHaltenbanken, Norway; U. Jurassic

Yemen Arab Republic; U. JurassicMonterey, California; Miocene

Marine

Denver Basin; L. CretaceousHaltenbanken, Norway; L. Jurassic

Mahakam Delta; TertiaryNiger Basin

Lake Chad; Santonian & EoceneGreen River Fm; Eocene

Doseo Basin, Chad; L. Cret. South Sumatra; L. Miocene

Lake Chad; Coniacian

Colombia; Aptian-Albian

Salinity

Paralic Lacustrine/Terrigenous

1 2 4 6 8 10 20 302515 35

Use of Hopane/Sterane Ratio as Source Facies Indicator

Use of C28/C29 Sterane Ratio as Age Indicator for marine source rocks

Simplified refining processes

Red: straight-run products containing biomarkers

Blue: processed products

VPS

APS

VPS

hy

jet fuel

diesel

gas oil

VGO

resid

gas

naphtha

hydrocrackerhydrocracking

product

hydrofiner hydrofining

product

FCC FCC product

coker coker oils

Lube Unit lube oils

distillates

Fate of biomarkers in refining processes

• Most of biomarkers survive the straight run processes.

Their presence in products depends on volatility.

• Commonly used biomarkers, steranes and hopanes,

concentrated in gas oils.

• Metalloporphyrins are concentrated in resids and heavy oils.

• Catalytic cracking processes destroy or alter most of the biomarkers.

Biomarker applications in downstream

• differentiation of straight run versus processed intermediates/products

• as measurement of severity of processes

• as fingerprints to distinguish from naturally occurring pollutants

Waters GCT (GC/Time-of-Flight) with a FI Source

Blend 10-7-03

2.50 5.00 7.50 10.00 12.50 15.00 17.50 20.00 22.50 25.00 27.50 30.00 32.50 35.00 37.50 40.00Time0

100

%

T31212015 TOF MS TIC

3.00e4

Blend 10-7-03

40 50 60 70 80 90 100 110 120 130 140 150 160 170 180 190 200 210 220 230 240 250 260 270 280 290 300m/z0

100

%

T31212015 579 (15.464) Cm (3:1398-(1398:1621+2:3)) TOF MS 3.75e5201.96

156.09

142.07134.11

120.09

106.08

92.06 98.11 112.12

132.09

148.12

170.10

160.12

184.12

182.11

176.06 196.12

203.96

206.11

210.13220.12

240.28 254.30 268.32

• GC separates components

• Time correlates to b.p. on a

nonpolar column

• FI produces only molecular ions

• Reflectron TOF allows accurate

mass measurement

Time scale Mass scale

• Configuration

• Key features

Reflectron

GC MS

GCMS

Heidrun 150N 11/20/03 5dl

20 40 60 80 100 120 140 160 180 200 220 240 260 280 300 320 340 360 380 400 420 440 460 480 500 520 540 560 580 600m/z0

100

%

T40217009 877 (42.882) Cm (497:1053-(1084:1349+2:492)) TOF MS 1.15e5372.382

362.395

348.379

346.364

334.363

332.348

320.348

318.332

316.317

306.332

302.301

43.056

29.041

292.317

290.301

286.270

386.398

400.414

404.444

418.460

420.474

432.477

434.491

446.493

448.508

460.509

474.527

478.557

Field Ionization yields molecular ion profile

mass

inte

nsity

fragment ions from

isoparaffins

0

1

2

3

10 15 20 25 30 35 40 45 50

Carbon Number

wt%

2 0 -2 -4 -6 -8 -10

Biomarker fingerprint shown in lubricant oil basestock

steranes

hopanes

1-ring cycloparaffins

paraffins

2-ring cycloparaffins

3-ring cycloparaffins

5-ring cycloparaffins

4-ring cycloparaffins

Environmental applications

• Biomarkers as fingerprint for contamination source identifications

• seeps from oil spills

• ship cargo leaks versus refined products

• tar ball identification

• Doping of biodegradation resistant biomarkers, such as steranes and

hopanes, can be used for measurement of efficiency of remediation

of environmental contamination.

• Diamondoids resist biodegredatation and even catalytic processes,

could be good candidates as tracers in refining and environmental

applications.

Relative extent of biodegradation for various biomarker classes

• General trend: n-

paraffins>isoparaffins>

cycloparaffins>aromatics

• Hopane can be used as

an internal marker for oil

depletion determination.

Determination of oil depletion by hopane Content

Hopane Conc. (in ppm)

Calculated Oil Depleted

Gravimetrically Measured Depletion

Crude oil 255 0% 0%

521 F Plus (a) 366, 355, 373 30 1% 30%

600 F Plus (b) 418, 440 41 1% 40%

(a) after topping at 521F

(b) after topping at 600 F

• Hopane analysis provides numerical values for the efficacy of

remediation

19

Provided by Robert Nelson and Chris Reddy of Woods Hole Oceanographic Institutition

Rtx-1, 60 m x 0.25 mm x 0.25 µm

GCxGC biomarker fingerprints

GCxGC 191 Da and 217 Daromatograms (provided by LECO)

Summary - Petroleum Biomarkers

• important class of compounds for upstream geochemical information

• little used in downstream process controls and monitoring

• widely used in environmental area as fingerprints for contamination

source identification, mainly by GC-MS.

• biodegradation resistant biomarkers - good internal standards for oil

spill damage and remediation assessment.

Contact information:

CSH – hsu@magnet.fsu.edu

FFI – research.fsu.edu/ffi