Gasification

University of WyomingSchool of Energy ResourcesCoal Gasification Conference

February 28, 2007

Integrated Gasification – Combined Cycle 101

Richard D. BoardmanINL R&D Lead for

Gasification & Alternative Fuels

Why Coal ?

What is gasification ?

How can gasification be used ?

How does gasification compare to traditional pulverized coal plant for power generation?

Why is gasification important to Wyoming ?

Carbon -Today’s Currency of Energy

12C

Biomass

Organisms

Bitumen, Petcoke

Peat

Coal

Oil

Kerogen

Natural Gas

Lignite or Brown Subbituminous Bituminous Anthracite

Subbituminous coal near Sheridan

Wyoming Buckskin Mine

Gasification from 1,000 meters

Carbon, Oxygen, Hydrogen, Nitrogen, SulfurAsh, Moisture, Mercury, other metals

Excluded (Liberated) Minerals

Coal Particle

Included (Locked) Minerals

C OH O-

C -O OH Ca+2

C OH

O- Na+

Organically Associated Elements

Coal Molecule – Subbituminous

CH3 O

C

H

H2

H H

H2

H2

H2

O

OH H2

H H

C H H

C H H

N H

H2 O C

C H

H H

H

H2 OH

H2 H2

S

C HH

CH3

C

H2

CH3

O

H O

H H2

H2 C H H

C OH

O

H O

H

C H

N

H2

H2

SH

OH

OH

H

O H2

H2

H2

CH3 CH3

C CH3 H

C H HH2

H2

O

C H H

OH

Nitrogen as pyroles

Organic Sulfur andInorganic Sulfur FeS

VisbreakerCrude

Petro. Coke

Pittsburg #8

Illinois #6Bitum.

Wyoming Sub-Bit.

NDLignite

Moisture wt% - 1.1

90.83.20.80.82.11.2

12,150

0.42

5.2 13 30.2 33.5

C, wt% 85.3 73.8 59.8 48.2 39.6H, wt% 10.8 4.9 4.1 3.31 2.6S wt% 4.0 2.13 3.7 0.37 0.5N wt% 0.3 1.4 1.1 0.70 0.7O, wt% 0.2 1.9 7.6 11.9 9.7Ash, wt% 0.15 5.0 10.7 5.3 15.9HHV – AR(BTU/lb) 13,500 13,260 10,982 8,340 6,010

H:C Ratio 1.52 0.80 0.82 0.82 0.79

Fuel Properties Differ Markedly

Char

Oxidized Char Products

Bulk Gas Phase

Ash Slurry Liquid

Raw Coal

Vapor

Volatiles from

Raw Coal

Bulk Gas Phase

Char

Oxidized Char Products

Bulk Gas Phase

Ash Slurry Liquid

Raw Coal

Vapor

Volatiles from

Raw Coal

Bulk Gas Phase

Temperature

Tight volatiles(pyrolysis)

Moistureand lightvolatiles

1. CO Oxidation CO + ½ O2 → CO2 -283 MJ/kmol2. CO Shift CO + H2O → CO2 + H2 -41 MJ/kmol3. Partial Oxidation CnHm + n/2 O2 → n CO + m/2 H2 slight exothermic4. Methane Reforming CH4 + H2O ↔ CO + H2 +2-6 MJ/kmol

Ash Melting

CharGasification

& WGS

5. Full Oxidation C + O2 → CO2 -394 MJ/kmol6. Partial Oxidation C + ½ O2 → CO -111 MJ/kmol7. Water Gas Reaction C + H2O → CO +H2 +131 MJ/kmol8. Boudouard Reaction C + CO2 → 2 CO +172 MJ/kmol9. Methanation C + 2 H2 → 2 CH4 -75 MJ/kmol

Major Homogeneous & Heterogeneous Reactions

Combustion vs

Gasification

0%

10%

20%

30%

40%

50%

60%

0.25 0.75 1.25 1.75 2.25 2.75 3.25 3.75

Equivalence Ratio, Φ

mol

-%

CO

H2

H2O

C

CO2

Combustion vs Gasification

SyngasFlue Gas

Combustion/Gasification Stages

Relative Char Reaction Rate: O2 >> H2O > CO2 > H2

Full Oxidation C + O2 → CO2 -394 MJ/kmolPartial Oxidation C + ½ O2 → CO -111 MJ/kmolWater Gas Reaction C + H2O → CO +H2 +131 MJ/kmolBoudouard Reaction C + CO2 → 2 CO +172 MJ/kmolMethanation C + 2 H2 → 2 CH4 -75 MJ/kmol

Char Reactivity (Rates):Black Liquor > Lignite Char > Sub-B. char > Bit. Char > Pet. Coke

0

1000

2000

3000

4000

5000

6000

0.25 0.75 1.25 1.75 2.25 2.75 3.25 3.75

Equivalence Ratio, Φ

ppm

CO CS2

H2S

SO2

Behavior of Gas-Phase Sulfur

ReducedOxidized

Mechanisms for Volatile Coal Nitrogen

Coal Nitrogen HCN

CN

NCO

N2O

NH N

NO

N2

+O

+OH +OH +NO

+H +H, OH

+OH

+H

+NO

+OH Fuel-Lean Bituminous Coal

Coal Nitrogen HCN

HOCN

HNCO NH2 NH3

N2

+OH

+OH +H

+H +H, H2O

+NO

Fuel-Rich Bituminous Coal

Coal Conversion and Electric Power Generation

Coal

PrimaryAir Fans

CoalPulverization

PrimaryAir

ForcedDraft Fans

OverfireAir

Ash HandlingSystem

Ash

Ash

Feed WaterHeaters

Feed WaterHeaters

Deaerator

Boiler Feed Pumps

Hot Well

CondensatePumps

GeneratorHP IP LP LP

SteamTurbines

Boiler FeedPump Turbine

Drives

AmmoniaPump

Ammonia

Flue Gas

WetScrubber

Baghouse

Scrub Pump Gypsum-Water to Dewatering & Drying

Scrub Tank

GACBed

Stack

Lime Slurry

Oxidation Air

Lime Pump

Oxidation AirBlower

Supercritical PC Power Generation Block Flow Diagram

100 MW Coal

15 MW Waste

85 MWSteam

45 MW Coolingplus parasitic

4O MW CoalElectricity

Conventional Power Plant Configuration

Sub-Critical: 2400 psig steam / 1000 °F / 37.5% eff.Super-Critical: 3500 psig steam / 1050 °F / 40% eff.Ultra- supercritical: 4500 psig steam / 1100 °F / 42% eff.

Simple Cycle, Two-Shaft Gas Turbine

Brayton Cycle

Gas Turbine Principles

Combined Cycle / Gas-Steam Turbine

38 MWeCombustion

19 MW Steam

100 MWNatural Gas

Principle of Combined Cycle

38 + 19 = 57% for NGCC

Altitude Correction Curve

16% Derate

Temperature Correction Curve

IGCC Electrical Power Generation

WabashConocoPhillips E-Gas(Destec)

TampaGE-CVX (Texaco)

Fixed-Bed Gasifier

Steam & oxygen Ash

Gas

Coal (5 – 0.5 cm)

500 1000 1500 2000

Gas Coal

Steam and oxygen

Ash

Temperature, K

Fixed-Bed Gasifier

Steam & oxygen Ash

Gas

Coal (5 – 0.5 cm)

DryingDevolatilizationVolatiles CombustionChar gasificationChar oxidationAsh melting

Tars and OilsCH4, moisture,light gases

High carbon burnoutDry bottom or slag

Fixed Bed Gasifier

Steam & oxygen Ash

Gas

Coal (5 – 0.5 cm)

GasLow tars and oilsMainly CO and H2

DryingDevolatilizationVolatiles CombustionChar gasification

Low carbon burnoutDry bottom

Steam and Oxygen

Fluidized Bed Gasifier

Gas

Char Steam & oxygen

Coal (~0.5 cm)

Carry-over

500 1000 1500 2000

Gas Coal

Steam and oxygen

Char

Temperature, K

Moderate carbon burnoutDry bottom

Moderate tars and oilsMix of CH4, CO and H2

Examples of Commercial Gasifiers

Fixed-Bed (Lurgi) So. Company Transport

(KBR Design Basis)

DisengagerSyngas

Coal

MixingZone

Riser

Loopseal

Cyclone

Standpipe

J-leg

StartupBurner

O2/AirSteam

O2/ AirLoopseal

Entrained Flow Gasifier Gas

Ash

Slag Coal

(<0.15 mm)

Steam & oxygen

500 1000 1500 2000

Gas

Coal Steam and oxygen Slag

Temperature, K

Very low tars and oilsMostly CO and H2, CO2, H2O

High carbon burnout

Examples of Commercial Gasifiers

GE-CVX (Texaco)

ConocoPhillips-EGAS (Destec)

Siemens-Sustec (Noell)

Coal ICGG

GE/CVX(Texaco)Gasifier

CryogenicASU

SlurryPrepPlant

SlurryPump

SyngasCoolers

WaterScrubber

Claus Process

HeatExchange

HRSG

Air

O2Illinois #6 orKentucky #9

Coal

CoalSlurry

BFW

LockHopper

Slag

BlackWater

System

Water

Soot

Syngas700°F

RecycleWater

Syngas320°F

Steam

COSHydrolysis

AmineSulfur

RemovalScrubber

AmineRegen-erator

CO2, H2S

Syngas100°F

N2

Syngas350°F

Elemental Sulfur

7FA or 7FBGas Turbine

Generator

Air

ExhaustGas

Steam

Stack

ExhaustGas

CondensingSteamTurbine

Generator

Makeup WaterProcess

Condensate

BFW

BFW

BFW Pump

SteamHeater

HeatExchange

StackExhaust

ACBed

100 MW Coal

-9 MW O2 Separation

- 43 MWCooling 22 MW

SteamTurbine

30 MW Gas

Turbine15 MW Reactor Steam

80 MW HHV Gas

~ 50 MWSteam

30 + 22 – 9 (ASU) = 43%

GE/CVX(Texaco)Gasifier

CryogenicASU

SlurryPrepPlant

SlurryPump

SyngasCoolers

WaterScrubber

Claus Process

HeatExchange

HRSG

Air

O2Illi nois #6Coal

CoalSlurry

BFW

LockHopper

Slag

BlackWater

System

Water

Soot

Syngas700°F

RecycleWater

Syngas320°F

Steam

COSHydrolysis

AmineSulfur

RemovalScrubber

AmineRegen-erator

CO2, H2S

Tai l GasReducti on

CO2

Syngas100°F

ReciprocatingCompressor

N2

Syngas350°F

Elemental Sulfur

ShiftConversion

Stage 1

ShiftConversi on

Stage 2

Syngas900°F

HeatExchange

Syngas650°F

Steam

7FA or 7FBGas Turbine

Generator

Air

ExhaustGas

Steam

PSACO2

Separation

Syngas100°F

H2O, H2S

CO2, CO, H230 psia

N2,Ar

Steam

BFW

CO2, CO, H2

CO2 to Sequestration or EOR

Pump

Stack

ExhaustGas

CondensingSteam

Turbine

Generator

Makeup WaterProcess

Condensate

BFW

BFW

BFW Pump

HeatExchange

BFW Steam

H2 ProductH

2

H2Comp.1st Stage

Recompression

ACBed

SteamHeater

HeatExchange

K/ODrum

Cooler

K/ODrum

Comp.2nd Stage

Cooler

K/ODrum

DehydrationUni t

Comp.3rd Stage

Cooler

Separator

H2

CO2

Water

(optional )

HT & LT ShiftConverters

PSA for H2/CO2separation

CO2 liqueficationby compression

ICGG & FutureGen

IGCC vs PC Combustion Considerations

• Efficiency• On-line availability• Turndown (base and peak operations)• Emissions• Water consumption• Economics (capital, construction and

operating) • Experience

Efficiency

• Sub-critical PC: 2,400 psig / 1000 °F / 37.5% eff.• Super-critical PC: 3,500 / 1050 ° F / 40% eff.• Ultra-supercritical PC: 4,500 / 1100 °F / 41.5% eff.• IGCC: Bituminous Coal / 42% eff.• IGCC: Sub-bituminous Coal / 40% eff.

On-Line Availability

• Sub-critical PC: > 96%• Super-critical PC: > 93% (Europe)• Ultra-supercritical PC: > 90% (Japan, unknown)• IGCC- Bituminous Coal: 85 – 92% (Tampa)• IGCC- Sub-bituminous Coal: 85 – 95 % (Prenflo)

Turndown Capability

• PC: 50 - 60% Peak capacity• IGCC: 70 – 80% Peak capacity

Emissions for PRB Coal

• PC with FGD (sulfur), SCR (NOx), carbon injection (Hg)• IGCC with Purisol (sulfur), SCR (NOx), carbon bed (Hg)

• PM – IGCC about 2x less • CO and VOC’s - IGCC 3x less • NOx - IGCC 3x less• SO2 - IGCC 4x less• Hg - About the same, but 50-100x less carbon used for

IGCC

Water Consumption

• IGCC, Slurry-Feed: About 30 % less• IGCC, Dry-Feed: About 50% less

Carbon Control

• PC Boilers:– amine or ammonia (wet) scrubbers– oxy combustion

• IGCC:– amine, purisol, rectisol, or other

scrubbing

Economics

• Supercritical PC Boilers: $2,000 - $2,500 kW installe• IGCC: $2,500 - $3,500 kW installed

• IGCC cost reduction considerations:– Need US fabrication capability– Construction experience– Turbine designs for altitude– Use surplus syngas to dry coal and/or fire HRSG– air-blown gasifiers– Design gasifiers to match ASU and gas turbines

How else can gasification be used ?

•

• Polygeneration of power, fuels, hydrogen, etc.• Efficient conversion of coal to syngas,

transportation fuels, and fungible refinery feed• Feedstock for chemical plants

– Ammonia → ammonium nitrate →explosives or fertilizer

– polymers, pharmaceuticals, sulfur, etc.– Hydrogen generation

Coal to Liquids (Fischer-Tropsch)

WaterScrubber

Coal

Slag

BlackWater

System

Soot

Syngas

SuperheatedSteam

BFW

BFW Pump

ActivatedCarbon

Bed

Compression

SyngasCooler

Steam

BFW(jacket)

Syngas

MPS(jacket)

HPS

MPS

Cyclone

Fly Ash

Condenser

Water

RectisolProcess

(H2S, CO2 Removal)

Purge Gas

CO, H2

H2S, CO2

ClausProcess

ElementalSulfur

Byproduct

SCOTProcess

Claus Tail Gas

SCOT Offgas

CO2

MPS

Generator

CondensingSteam Turbine

EntrainedFlow

Gasifier

Pulverizer

CoalDrying

Coal(Dried &Sized)

Separation

MiddleDistillate

&Light

Liquids

HeavyLiquids

Water

Compression

Gas

Separation

Water

HeavyLiquids

MiddleDistillate

&Light

Liquids

Hydrocracker

DistillationColumns

HeavyLiquids

NaphthaProduct

DieselProduct

F-TReactor

F-TReactor

Tail Gas

H2 Membrane

CompressionH2

Recycle Quench Gas

TailGas

BFW

TailGas

BFW

BFW

BFW

MPS

BFW

MPS

CryogenicASUAir

O2

N2

SourShift

ReactorHPS

Compression

Pump

CO2Product

TEGDehydration

Unit

HRSG

AirExhaust

Gas

Stack

Exhaust Gas

BFW Steam Generatedvia Heat Recovery

Gas Turbine Generator

Compressor

Eastman Chemical Process

Eastman ChemicalKingsport, TN

High-value chemicals productionSasol synfuelsSecunda plantLiquid fuel and

chemical feedstock

Wyoming Coal is Opportune Feedstock for Synthetic Gas, Fuel, and Chemicals

Naphtha

Fischer-TropschLiquids Acetate Esters

Ketene

Acetic AcidDiketene &Derivatives

WYOMING COAL

Power & Steam CO Formaldehyde

PVAVAMWaxes

Diesel

Alpha Olefins

Car Fuel

Acetic AnhydrideMethyl AcetateMethanolSynthesis GasGasification

Distrib. Co-Generation

Dimethyl EtherH2Town Gas

Alpha Olefins

Oxo Chemicals

Polyolefins

Acrylic Acid/Acrylates

Ammonia

Urea

Urea/Ammonium

Nitrate

Hydrogenation Processes Fuel Cells

Acrylonitrile

Ammonium Nitrite

Ethylene & Propylene

CO Chemicals

Syn. Natural Gas

There is a Bright Future for Coal Gasification in Wyom

Education, Energy, Economy, Environment, are KEY to Wyoming’s Future

QUESTIONS?