Sweetening and sulfur recovery of sour associated gas and lean acid gas in the middle east

SPE 172058

Sweetening and Sulfur Recovery of

Sour Associated Gas and Lean Acid Gas

in the Middle East

Peter Hauwert, Ph.D. - Frames

Sour Associated gas

Flaring

• Middle East annually flares 29 BCM of associated gas [1]

• Feed for 20 mtpa LNG plant (12 B$ @ 12 $/MMBTU)

Reserves

• 57% contains <0.1%v H2S [2]

• 32% contains 0.1-1%v H2S Non-produced gas with GOR>1000 scf/bbl, for values available in IHS EDIN

Small SRU

• Relevant for >25% of gas currently not produced

BCM = 109 m3 MT = 109 kg Tscf = 1012 scf = 28 x109 m3

[1] World Bank - Global Gas Flaring Reduction partnership (2007)

[2] Golombok (Shell), E&P 2008 (from IHS EDIN database)

<100 ton/d S: <0.1%, <0.5%,<1% H2S

6.2

Outline Sulfur

recovery process

comparison

Thiopaq O&G Process

Process in desert

environments

Case study

100 kg/d S 1 t/d S

10 t/d S

50 t/d S

200 t/d S

10

100

1,000

10,000

100,000

1,000,000

0.1 1.0 10.0 100.0

H2S

coce

ntr

atio

n in

fe

ed

(%

vol.

)

Feed gas Flow (x106 Nm3/d)

Assessment of RFQs for H2S containing feeds (up to 2012)

(1 x106 Nm3/d ≈ 37 MMSCFD)

100% H2S

10% H2S

1% H2S

0.1% H2S

1000 ppm

100 ppm

10 ppm

Small Scale Sulfur Recovery

SPE172058 • Sweetening and Sulfur Recovery of Associated gas in the Middle East • Peter Hauwert • 4 / 22

Small Scale Sulfur Recovery

Small scale sulfur recovery processes

Aqueous iron Thiopaq O&G

CrystaSulf

Catalytic

oxidation

SPE172058 • Sweetening and Sulfur Recovery of Associated gas in the Middle East • Peter Hauwert • 5 / 22

Comparison commercial small scale SRU Aqueous iron Thiopaq

O&G Crysta

Sulf Catalytic oxidation

Sulfur load (tonne S/d) 1-20 1-100+ 1-20 1-20 (-200)

H2S removal (%) 99.9+ 99.9+ >99.8 90 % /pass

H2S specification (ppmv) < 4 < 4 (> 4 bar)

< 25 (atm)

< 4 4-100

Pressure <30 bar LP / HP HP LP / HP

S quality Landfill Agro / Claus Claus Claus

Operational since ‘70s (LoCat)

‘90s (Sulferox)

1993 (biogas) 2002 (NG)

2005 2005

References > 200 (LC) > 30 (SF)

> 200 (bio) 16 (NG)

< 5

< 5

Operations & HSE - ++ + +

Comments Foam issues Water consumption SO2 needed Only <10% H2S

Adapted from: Lee, GPA Europe 30th Annual Conference, (2013)

SPE172058 • Sweetening and Sulfur Recovery of Associated gas in the Middle East • Peter Hauwert • 7 / 22

• Low pressure gas o 1887 – Winogradsky discovers sulfur oxidizing bacteria

o 1989 – Buisman develops Thiopaq process

o 1993 – Thiopaq pilot plant at wastewater treatment Eerbeek

o 1994 – 1st Commercial unit by Paques (water treatment)

o 2014 - >200 commercial references (biogas)

• High pressure gas o 1997 – Thiopaq O&G tests at 60 bar natural gas (with Shell)

o 2002 – 1st commercial Thiopaq O&G unit

o 2014 – 16 commercial references (natural gas / acid gas / associated gas)

Thiopaq O&G - History

SPE172058 • Sweetening and Sulfur Recovery of Associated gas in the Middle East • Peter Hauwert • 8 / 22

Thiopaq O&G – Process description

Bioreactor

Decanter

Sulfur

Air out

Air in

Flash gas

Feed gas

Product gas

Condensate

NaOH water nutrients

( )

Feed pre-treatment Absorber Regeneration Solid sulfur separation

Bleed

Flash (optional)

Settler

Absorber

H2S + OH- HS- + H2O

CO2 + OH- HCO3-

with carbonate buffer (pH 8.0-9.5)

Regenerator

HS- + ½ O2 Sx + OH-

HCO3- CO2 + OH-

HS- + 2 O2 SO42-

+ H+

2 HS- + 2 O2 S2O32- + H2O

Control

SPE172058 • Sweetening and Sulfur Recovery of Associated gas in the Middle East • Peter Hauwert • 9 / 22

Thiopaq O&G in the Middle East?

? ?

?

? ?

? ?

“It’s hot!!”

“We don’t have water”

“They’re bacTeria” “what do I do

wIth the sulfur?”

“Is it proven?”

(Feedback we have had from clients)

Technical applicability in desert • Ambient conditions

o -5 oC (night, desert) up to 55 oC (summer daytime)

o Black bulb temperatures up to 85 oC

• Remote operation

o Manpower for operation

o Maintenance

• Remote construction

o Transportation difficulties

o Quality control

SPE172058 • Sweetening and Sulfur Recovery of Associated gas in the Middle East • Peter Hauwert • 11 / 22

Applicability – Ambient temperature • Feed gas cooling

o Hydrocarbon dewpoint (30-35 oC)

o Slugs: well-fluids and heavy hydrocarbons

o Stabilizes operation of absorber

• Solvent cooling (40 oC) o Absorption & reaction enthalpy

o Bacteria 35-45 oC optimal

Cooling system (60-100 kW / ton S)

Insulation

SPE172058 • Sweetening and Sulfur Recovery of Associated gas in the Middle East • Peter Hauwert • 12 / 22

Bioreactor

Decanter

Sulfur

Air out

Air in

Flash gas

Feed gas

Product gas

Condensate

NaOH water nutrients

Feed pre-treatment

Absorber RegenerationSolid sulfur separation

Bleed

Flash (optional)

Settler

Cooling system

Applicability – Solar irradiation • Solar irradiation

o 1600-2800 kWh / m2 Black bulb temperature 85 oC

Light / reflective coating

Shading

Insulation of piping

Adapted from SolarGIS © 2014 GeoModel Solar

SPE172058 • Sweetening and Sulfur Recovery of Associated gas in the Middle East • Peter Hauwert • 13 / 22

Thiopaq O&G plant constructed in Egypt:

Kijlstra, Laurence Reid Gas Cond. Conf (2001)

Applicability – Remote operation • Stable operation

o Large buffer solution

o Adaptive bacteria

• Suitable for associated gas

o Unstable feed flow

o Changing concentrations

Plant operation data in Netherlands plant,

courtesy of Paques B.V.

SPE172058 • Sweetening and Sulfur Recovery of Associated gas in the Middle East • Peter Hauwert • 14 / 22

Applicability – Remote operation • Limited operator attention

o Simple control loops

o Minor daily analyses & maintenance

o Robust operation

o Ambient conditions

o Simple start-up & shutdown

• Limited maintenance

o Main equipment static columns & tanks

o Rotating equipment installed spares

SPE172058 • Sweetening and Sulfur Recovery of Associated gas in the Middle East • Peter Hauwert • 15 / 22

Applicability – Remote operation • Consumables

o Potable water quality o Transport by truck or on-site generation (well)

o Caustic

o Nutrients

o No fuel gas needed & limited power consumption

• Case by case CAPEX-OPEX evaluation necessary

SPE172058 • Sweetening and Sulfur Recovery of Associated gas in the Middle East • Peter Hauwert • 16 / 22

Applicability – Remote construction • Modularized construction

o Main vessels road transportable

o Pumps & small equipment skid-mounted

o Controlled manufacturing environment

o Limited site work

• Fast track possible

o No higher alloys (Incoloy / Titanium /Duplex)

o Limited long-lead items

o Standardized design

SPE172058 • Sweetening and Sulfur Recovery of Associated gas in the Middle East • Peter Hauwert • 17 / 22

Case study • Impact of desert environment – case study

o Typical associated gas composition 0.5%v H2S, 5%v CO2

o 550 kNm3/d [20 MMSCFD] (40 oC, 3 bar) 4 tpd S

o Western Europe vs. Middle East

• Design: 165 m3/h solvent circulation (For more details see paper)

o 1 absorber (1.8 m ID x 18.3 m TT) & 3 aerated tanks (4.0 m ID x 8.1 m TT)

• Consumables: 1 m3/d caustic (50wt%) & 17 (ME)-18 (EU) m3/d water

• Power: o Feed cooling (78 kW) & Solvent cooling (158 kW, EU / 226 kW, ME)

o Air blower (110 kW) & Pump duty (35 kW )

SPE172058 • Sweetening and Sulfur Recovery of Associated gas in the Middle East • Peter Hauwert • 18 / 22

Case study – Design Middle East

Western

Europe

SPE172058 • Sweetening and Sulfur Recovery of Associated gas in the Middle East • Peter Hauwert • 19 / 22

Case study – Relative CAPEX

SPE172058 • Sweetening and Sulfur Recovery of Associated gas in the Middle East • Peter Hauwert • 20 / 22

106% 100%

Conclusions • Small-mid scale sulfur recovery processes compared

o Several maturing options available

o Thiopaq O&G technically and commercially attractive

• Thiopaq O&G suitable for sour associated gas treatment o Good performance also at low pressures

o Robust toward variations in feed

o Sweet spot for associated gas

• Thiopaq O&G applicable in desert environment o Limited impact of ambient conditions on overall costs

o Low operator attendance

o Modular construction possible

SPE172058 • Sweetening and Sulfur Recovery of Associated gas in the Middle East • Peter Hauwert • 21 / 22

Slide 23

Frames

Lennard Spit

Paul Mulders

Hein Kandelaar

Lex Rotteveel

Elwin Janssen

Paqell

Gijs van Heeringen

Hans Wijnbelt

Paques

Erik van Zessen

Acknowledgements

Thank you for your attention