4 oct, 2018 refcomm valencia 1 - refining …...company profile •engineering company specialized...

4 Oct, 2018 RefComm Valencia 1

SRU Thermal Reactor Chemistry & Design

Roelof ten Hooven

Area Sales Manager


Company Profile• Engineering company specialized in process

combustion equipment

• Founded in 1919

• ± 75 employees


Goals of the SRU

• Recover elemental sulfur (S2-8) from all sulfur species in the feed gases (AAG and/or SWSAG).

• Destruct other harmful components of the feed gases.

• Limit the formation of new harmful substances.

Basically, comply with emissions regulations!


Typical Sulfur Recovery Unit


MAINBURNER

ACID GASCOMB AIR

1st LINEBURNER

FUEL GASCOMB AIR

2nd LINEBURNER

FUEL GASCOMB AIR

RGGBURNER

FUEL GASCOMB AIR

INCINERATORBURNER

FUEL GASCOMB AIR

WASTE HEAT RECOVERY SECTION

REACTIONFURNACE

INCINERATORCHAMBER


MIXINGCHAMBER

MIXINGCHAMBER

MIXINGCHAMBER

CONDENSER

CONDENSER

CATALYTICCONVERTOR

CATALYTICCONVERTOR

CONDENSER

QU

ENC

H

REG

EN

SULFUR

AB

SOR

BER

SULFUR

SULFUR

REDUCTION REACTOR

Sulfur Recovery Unit Thermal Stage


MAINBURNER

ACID GASCOMB AIR

1st LINEBURNER

FUEL GASCOMB AIR

2nd LINEBURNER

FUEL GASCOMB AIR

RGGBURNER

FUEL GASCOMB AIR

INCINERATORBURNER

FUEL GASCOMB AIR


REACTIONFURNACE

INCINERATORCHAMBER


MIXINGCHAMBER

MIXINGCHAMBER

MIXINGCHAMBER

CONDENSER

CONDENSER

CATALYTICCONVERTOR

CATALYTICCONVERTOR

CONDENSER

QU

ENC

H

REG

EN

SULFUR

AB

SOR

BER

SULFUR

SULFUR

REDUCTION REACTOR

4 Oct, 2018 7RefComm Valencia

Thermal Stage Objectives

• 65-70% Sulfur Recovery

• Ammonia Destruction

• Hydrocarbon Destruction

• By-product Conversion


Sulfur formation in the Reaction Furnace

2H2S + SO2 1½S2 + 2H2O

Claus reaction:

Hydrogensulfide

Sulfurdioxide

Sulfur water

Acidgas


Sulfur formation in the Reaction Furnace

H2S + 1½O2 SO2 + H2O

2H2S + SO2 1½S2 + 2H2O

Combustion zone

Reaction zone

OxygenHydrogensulfide

WaterSulfurdioxide

Hydrogensulfide

Sulfurdioxide

Sulfur water

Acidgas

Air


Sulfur formation

H2O

SO2H2

Partial

H2S oxidation

H2S cracking SO2 reduction

H2S

½O2¼O2

½H2Sulfur½H2O

H2S

H2S

Oxygen

Water

Hydrogen

Oxygen

Water

Hydrogen 2H2

2H2O

Acid gas Acid gas

Acid gas Sulfur dioxide


Ammonia destruction

NH3 + ¾O2 ½N2 + 1½H2O


Ammonia destruction

NH3 + ¾O2 ½N2 + 1½H2O

Ammonia conversionH2S oxidation

NH3 ½SO2

½N2 ½H2S ¾O2

½H2O

H2O+

Sulfur dioxide

Hydrogen sulfide

Ammonia

Nitrogen Oxygen

Water

Water

Acid gas

Air


Ammonia destruction

Remaining NH3 at MRF outlet:

• Expected < 20 ppm

• Guaranteed < 100 ppm

Provided:

• MRF operating temperature > 1300°C (2372°F)

• Residence time > 1 sec


Hydrocarbon destruction

CH4 + 2O2 CO2 + 2H2O


Hydrocarbon destruction

Oxidation

CS2 conversionCH4 CS2 CO2

2H2S SO2

2H2O

Carbon disulfide

Hydrogen sulfide

Methane Carbon dioxide

Water

CH4 + 2O2 CO2 + 2H2O

Sulfur

CH4 conversion

Sulfur dioxideSulfur

2O2Oxygen

Air


SRU Combustion Basics

The degree of combustion depends on 3 factors, the three T’s ofcombustion:

• Temperature

• (Residence) Time

• Turbulence

RefComm Valencia 174 Oct, 2018

SRU Temperature

The overall temperature in the main reaction furnace dependson:

• Chemical reactions– Heat release and absorption

– The stoichiometry

• Design conditions (set by process licensor)– Pre-heating of the combustion air / acid gas

– Oxygen enrichment

– Co-firing of fuel gas

– Bypassing part of the amine acid gas


SRU Residence Time

Minimum: determined by reaction kinetics

Longer: better destruction of impurities.

RefComm Valencia 19

Residence time section

4 Oct, 2018

SRU Turbulence

The flow pattern determines the shape of the flame, the degreeof mixing as well as the flame stability. Mixing is achievedthrough:

• Burner geometry– E.g. physical restrictions, swirlers, constrictions, etc.

• Pressure drop– Higher pressure drop = more energy!

• Design principle– Pre-mixing vs. diffusion flame principle


Resulting Burner Requirements

• Intense mixing of acid gas and oxygen

• Recirculation of flue gas


LMV Main Burner


LMV Burner Axial Velocity


Turbulent combustion


4 oct, 2018 refcomm valencia 1 - refining …...company profile •engineering company specialized...

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