SECA Core Technology Program Review Library/Research/Coal/energy systems...SECA Core Technology...

Onsite Fuel Processing R&D at the National Energy

Technology Center

Presenter: David A. Berry

November 16, 2001

SECA Core Technology Program Review

Descriptor - include initials /org#/date

Fuel ProcessingOverview

• Goal− Provide SECA fuel cell developers with reliable, low cost fuel processors.

• Objective− Develop fuel processing technology for application specific fuel types (natural

gas, gasoline, diesel,...).

• Technical Challenges− Deactivation of fuel reforming catalysts and fuel cell components are a

principle technology barrier:• Sulfur-containing fuels poison reforming catalysts and fuel cell anodes, causing

premature failure.• Carbon deposition on reforming catalysts, especially with the heavier

hydrocarbon fuels, deactivate the reformer.− Large, complex, slow-response fuel processors problematic:

• Many FC applications may require high power density design with “fast”response for transient operations.

• Technical Approach− Develop compact, modular processors that incorporate novel sulfur removal

technology and/or sulfur/coke tolerant catalyst systems..


FuelProcessor

PowerSection

PowerCondi-tioner

CleanExhaust

Fuel

Air

Steam

DCPowerH2

RichGas

UsableHeat &CleanWater

AC Power

Fuel ProcessingSimplified Fuel Cell System View


Fuel Processing - Introductioncont...

Reformer

FuelCell

Stack

Cathode

Anode

Fuel

Air

General Scheme:



SteamReformer

FuelCell

Stack

Cathode

Anode

Q Q

S

S-Fuel

Steam

Fuel

Steam Reforming:



CPOxReformer

Q

FuelCell

Stack

Cathode

Anode

S

S-Fuel

Air

Fuel

Catalytic POx: Q



ATRReformer

Q

FuelCell

Stack

Cathode

Anode

S

S-Fuel

Air

Fuel

AutothermalReforming:

Steam

Q


Sulfur poisoning

Coke Formation

High efficiency & thermal integration

Quick startup and transient response

Fuel Processing for SECAA variety of development issues


• Vision 21 Power Plants75% efficient plants

• Propulsion <$200?/kW

SECA Development: SECA Development: Progressive ApplicationsProgressive Applications

2005

• $800/kW• Prototype ($-Unit)

3 - 10 kW

2015

2010

• $400/kW• Commercial


Facilities & Infrastructure

Desulfurization

R&D

Reforming

R&D

Systems

Analysis

& Modeling

Approach to Program/Project Planning


Natural Gas/Synthesis Gas Sulfur Removal Technologies

MeOH

H2S Levels(ppbv)

Amine

Adsorbents

ZnO

700°C-50°C

Caustic

<10

<500

100-5,000

100-5,000

<20

<20

<100

N/A

50°C

MO

Oxidation

150°C

“Wet”

Membranes

Oxidation

350°C

“Dry”


“High Temperature H2S Removal”

• Project Objective− Assess high temperature H2S sorption/reaction technology as a method

of removing sulfur in compact SOFC systems• Technical challenges

• High sulfur removal efficiency• Resistance to sintering, Ostwald ripening, etc.• Stability of silica “free” binder systems and matrix materials• Lifetime analysis, capacity, regenerability

• Technical Approach− Perform thermodynamic study for suitable MO’s

• MO + H2S 6 MS + H2O− Perform lab-scale screening of suitable catalysts, matrix materials and

binder systems for high temperature H2S sorption/reaction


Zn2TiO4 Equilibrium Sulfur Removal Efficiency

1.00E-071.00E-061.00E-051.00E-041.00E-031.00E-021.00E-011.00E+001.00E+011.00E+021.00E+031.00E+04

0 200 400 600 800 1000 1200Temperature (oC)

Equi

libri

um H

2S

Con

cent

ratio

n (p

pmv)

0.1% 0.5% 1% 2% 5% 10% 20% 40%H2O Content

0.1 ppmvSOFC


CuO Equilibrium Sulfur Removal Efficiency

1.00E-07

1.00E-06

1.00E-05

1.00E-04

1.00E-03

1.00E-02

1.00E-01

1.00E+00

1.00E+01

0 200 400 600 800 1000 1200Temperature (oC)

Equi

libriu

m H

2S C

once

ntra

tion

(ppm

v)

0.1% 0.5% 1% 2% 5% 10% 20% 40%H2O

Content

0.1 ppmSOFC


“Selective Oxidation of Sulfur Compounds for Direct Sulfur Removal”

• Project Objective− Assess sulfur selective catalytic oxidation technology as a direct

sulfur removal technology at low temperatures for SOFC systems

• Technical Challenges− High sulfur conversion/removal efficiency

• H2S, Mercaptans− High activity, high throughput, optimization− Lifetime analysis

• Technical Approach− Perform lab-scale screening of suitable catalysts and supports,

e.g. removal efficiency, lifetime, SV− Kinetic measurements


“H2S Catalytic Partial Oxidation”

“Selective Oxidation of Sulfur Compounds for Direct Sulfur Removal”

“Sulfur Over Oxidation Possible”

“H2S Complete Oxidation”

•H2S + 1/2O2 6 1/8S89 + H2O

•4RSH + O2 6 2RSSR9+ 2H2O•Sulfur product retained in activated carbon catalyst’s micropores•High sulfur loadings possible•Thermal regeneration is necessary

•H2S + 1/2O261/nSn + H2O

•1/nSn + O2 6SO2

•4RSH + O2 6 2RSSR9+ 2H2O•Macroporous catalysts

necessary•High superficial velocities needed to ‘wick’ sulfur product away•Metal oxide catalysts employed

• H2S + 3/2 O2 6SO2 + H2O• Homogenous phase H2S complete oxidation

175oC 250oCTemperature

100oC


Equilibrium Removal Efficiency of the H2S Partial Oxidation Reaction

0

0.005

0.01

0.015

0.02

0.025

0 50 100 150 200 250 300 350Temperature (°C)

H2S

Con

cent

ratio

n (p

pbv)

H2O/H2S = 0.0

H2O/H2S = 1.0

H2O/H2S = 10

H2O/H2S = 100

H2S + 1/2 (O2 + 3.76 N2) = 1/n Sn + H2O + 1.88 N2


Effect of Temperature and Time on Stream on H2S Removal Efficiency

0

0.2

0.4

0.6

0.8

1

1.2

135 145 155 165 175

Temperature (°C)

H2S

Con

cent

ratio

n (p

pmv)

Start30 min60 min90 min120 min150 min180 min210 min240 min270 min300 min330 min

GHSV = 2,500Hr-1

P = 156.5 KPaO2/H2S = 5

Synthesis Gas Comp.:H2S 1,000 ppmvCO 35.91%CO2 12.30%H2 26.91%H2O 18.05%N2 6.73%


H2S Partial Catalytic Oxidation Performance in Natural Gas

0

0.4

0.8

1.2

1.6

2

105 115 125 135 145Temperature (°C)

Exi

t Con

cent

ratio

n (p

pmv)

H2S

SO2

COSGHSV=2,500 Hr-1

500 ppmv H2S inlet Bal. CH4

H2S:O2 = 1:2


SEM/EDS Sulfur Profiles in Activated Carbon Catalyst Pellets

8 hours at 1,000 ppmv H2S 16 hours at 1,000 ppmv H2S


Continuous Catalytic Oxidation of H2S

Metal oxide REDOX catalyst remained in oxide state

Sulfur product continuously Drips out


• OBJECTIVES− Provide adequate facilities to support RD&D for the SECA program.

• Identify and understand fundamental mechanisms of concepts proposed for fuel processing applications

• Explore R&D issues and demonstrate technology options at variousscales.

• Provide experimental validation of technology development

• TECHNICAL CHALLENGES− Fundamental issues must be studied at small scale with high analytical

precision where all operating variables can be isolated and controlled.− Facilities must be economical to operate and flexible− Processes deal with high temperature (pressure) combustable and toxic

gases − Effects of process scale must be understood.

Facility/Infrastructure Overview


• APPROACH− Develop labscale facility to generate fundamental data for technology

involving chemical reaction, separations, heat transfer, and mass transfer :

• H2S removal from Fuel Cell feedstocks• Kinetic rates for catalyst systems• Reaction Mechanisms (also failure mechanisms)

− Provide mid-scale platform to:• Bridge the gap between lab scale and commercial components -

minimize scaling issues.• Conduct validation testing and technology evaluation for program

participants (testing of fuel processors in SECA program).

Facility/Infrastructure Overview (cont.)


Generate fundamental, design, and operational data for applications involving separations, heat transfer, and mass transfer :

- H2S removal from Fuel Cell feedstocks- Kinetic rates for catalyst systems- Reaction Mechanisms (also failure mechanisms)

Fuel Processing Laboratory

Mini Reactors

Gas Absorption Column

Micro Reactor

Diffusion Coefficient Testers


Vapor Fuel

Liquid Fuel

Air

Water

NitrogenPressureBalance

ChemicalAnalysis

Miniature Reactor SystemB25 Fuel Processing Laboratory

Test Bed Capabilities:− Pressure: 0 - 450 psig− Temperature: 300 - 1800 °F− Space Velocity: 2000/hr - 105/hr


Fundamental Studies MicroreactorB25 Fuel Processing Laboratory

• System Volume = 0.8 cm3

• Sample can participate in reaction, be isolated quickly, and be subjected to Temperature Programmed Studies

• Instrument Capabilities:− Temperatures from -100

to 1100 °C− Operates near ambient

Pressure − Flowrates up to 75 sccm

5% CO95% N2

5% H295% N2

5% O295% N2

N2 Utility

CO2

AIRUtility

CH4

H2

N2 Utiltiy


Separation Membrane

Mixing Manifold

Component Test Stand

Carbon Desulfurizer

Hydro-Desulfurizer

Reformer

Explore R&D issues that demonstrate technology options for fuel-gas processing at a significant mid-scale levelAddress coal gas cleanup technology development as it relates to fuel cells and Vision 21

CAPABILITIES:

• 2000 SCFH of tailored synthesis gas

• 900 °C• 30 atmospheres• Reformer Modes:

• Partial Oxidation• Steam• Auto-thermal

• Multiple unit operations for fuel gas processing

Fuel Processing Research Facility


Facility Layout

• Located on the NETL-MGN Site

• Areas:− 2200 SQFT

of Research Area

− 1600 SQFT of Remote Operations Area

− 350 SQFT of Gaseous and Liquid Fuels Storage Area


FPRF Fuel Storage Area

Gaseous Fuels Storage

• Hydrogen

• Carbon Monoxide

• Hydrogen Sulfide

• Others if needed

Liquid Fuels Storage

• Diesel Fuel

• Others if needed


FPRF Process Area

• Manifold Rack

• Carbon Desulfurizer

• Preheater (H-100)

• Hydro-Desulfurizer


• Zinc Oxide Bed



• Reformer


FPRF Process Area Continued

• Hydrogen Separation Membrane

− UOP CRADA

• Water Tank


• Circulating Transport Reactor

• Support Equipment

• Prototype FP Test Bay

• Waste Incinerator

Date post:	25-Mar-2018
Category:	Documents
Upload:	lebao
View:	218 times
Download:	0 times

SECA Core Technology Program Review Library/Research/Coal/energy systems...SECA Core Technology...

Documents