hydrogen production by a thermally integrated atr based fuel processor

HYDROGEN PRODUCTION BY A THERMALLY INTEGRATED ATR BASED FUEL PROCESSOR

V. Palma1, A. Ricca1, B. Addeo1, G. Paolillo2, P. Ciambelli1

Department of Industrial EngineeringUniversity of Salerno, Fisciano (SA) - ITALY

[email protected]

1 Department of Industrial Engineering - University of Salerno, Fisciano (SA) - ITALY 2 R&D - SOL S.p.A, Monza (MB), ITALY

o Growing world energy demando Depletion of fossil fuels

ALTERNATIVE ENERGY SOURCES ARE NEEDED

Solar Nuclear GeologicalEolic

Hydrogen=

Energetic vector

Water hydrolysis

Hydrocarbons reforming

H2 Gree

n En

ergy

Fuel cells

Introduction

Hydrogen and Energy

Hydrogen

Steam ReformingPartial OxidationAutothermal Reforming

Preliminary syngas purification

Preferential oxidationMembrane separationPressure swing adsorption

Introduction

Hydrogen from hydrocarbons

HCAir H2O

Reformer

Water Gas Shift

Further purification

HYDROGEN

H2

Introduction

The AutoThermal Reforming

CH4 + y H2O + x O2 = a CO + b CO2 + c CH4 + d H2O + e H2 + f C(S)

Advantages• Easy to design Thermal integration of the reaction• Quick start-up Quick response to feed changes• Reactor compactness Feed versatility

Distributed H2 production for heat and energy power generation

High compactness and thermal efficiency of the reactor

Auto-Thermal Reforming (ATR)

Partial Oxidation

molKJH 3.206 molKJH 6.35

Steam ReformingCH4 + H2O = CO + 3 H2 CH4 + ½ O2 = CO + 2 H2

Aims

Aims of the work

To design and set-up a fuel processor based on auto-thermal reforming (H2 productivity 10 Nm3/h)

ATR – WGS Integration Compactness Thermal Integration

To perform preliminary tests Methane Natural Gas

AIMS OF THIS WORK

EXPERIMENTAL APPARATUS

Experimental Apparatus

Design Concept

Mix

ATR

Water

Air

Methane

WGS

SYNGAS

Heat

Exc

hang

er

SteamAir

REACTANT PREHEATING UP TO 300 ÷ 400°C

Integrated heat exchange system

No external exchangers Plant compactness Cost lowering

Plant layout

Experimental apparatus

FEED

SE

CTIO

N

ANAL

YSIS

SY

STEM

REACTION SECTION


ATR module

Temperature and composition measured close to the inner and outer sections of the catalytic bed

ATR CatalystGHSV 15000 h-1

Catalyst Volume 1000 cm3 (D 3.66 in)

Catalyst Shape Honeycomb monolith400 CPSI - WT 6.5 mil

Catalyst Supplier Johnson Matthey

Catalyst

Insulating Foam


WGS module

Temperature and composition measured close to the inner and outer sections of the catalytic bed

WGS CatalystGHSV ≈2500 h-1

Catalyst Volume 7500 cm3

Catalyst Shape PelletsD 5 mm

Catalyst Supplier KatalkoJMCatalyst


Heat exchange module

Steam Air Liquid waterCoils 5 9 10Tube per coils 9 5 9Surface (m2) 0.032 0.032 0.065

The use of coils increases heat exchange efficiency

Several coils mounted parallel-way to reduce pressure drops

Exchangers arrangement maximizes heat transfer and avoids methane cracking


Assembled reaction system

RESULTS AND DISCUSSIONMETHANE REFORMING

Results and Discussion

Methane ATR – Operating conditions

Test parameters

Fuel METHANE

H2O / O2 / CH4 0.49-0.75 / 0.60-0.65 / 1

ATR

GHSV 15,000 h-1

Catalyst Volume 1,000 cm3

Catalyst Shape Honeycomb monolith

WGS

GHSV 2,500 ÷ 3,000 h-1


Catalyst Shape 5 mm Pellets


Methane ATR - Thermal Profiles

Mixer ATR Heat Exchanger

WGS

Reactants pre-heating up to 360°C

Heat exchange module able to cool process stream to around 300°C in all conditions

Relevant heat loss in the WGS module


Methane ATR – Catalytic Stages Performances

H2O:O2:CH4 = 0.49:0.6:1

H2O:O2:CH4 = 0.6:0.65:1

H2O:O2:CH4 = 0.65:0.65:1

H2O:O2:CH4 = 0.75:0.65:1

0%

20%

40%

60%

80%

100%96

.7%

99.0

%

99.5

%

99.5

%

X_CH4 Eq. Therm

CH4

Conv

ersio

n

H2O:O2:CH4 = 0.49:0.6:1

H2O:O2:CH4 = 0.6:0.65:1

H2O:O2:CH4 = 0.65:0.65:1

H2O:O2:CH4 = 0.75:0.65:1

0%

20%

40%

60%

80%

X_CO WGS1 X_CO Therm. Eq

CO C

onve

rsio

n

Methane conversion very close to thermodynamic equilibrium

Full conversion in the last 3 tests

CO conversion less performant

WGS catalyst kinetic issues

H2O / CH4 O2 / CH4

Case 1 0.49 0.60

Case 2 0.60 0.65

Case 3 0.65 0.65

Case 4 0.75 0.65

H2O/CO T out CH4 H2 CO2 CO X_COExp. Therm. Eq. Exp. Therm. Eq. Exp. Therm. Eq. Exp. Therm. Eq. Exp. Therm. Eq.

Case 1 0.74 300°C 1.9% 2.0% 39.6% 39.6% 9.2% 12.2% 8.4% 4.4% 36.7% 66.9%

Case 2 0.70 327°C 0.4% 0.6% 40.3% 40.1% 11.0% 12.3% 6.5% 4.5% 52.1% 67.1%

Case 3 0.70 366°C 0.3% 0.3% 41.2% 40.3% 10.3% 11.7% 6.6% 5.3% 51.1% 61.3%

Case 4 0.85 372°C 0.3% 0.3% 41.5% 40.6% 11.1% 12.2% 6.2% 4.8% 52.5% 63.9%


Methane ATR – Stages compositions

H2O/C O2/C CH4 H2 CO2 CO X_CH4Exp. Therm. Eq. Exp. Therm. Eq. Exp. Therm. Eq. Exp. Therm. Eq. Exp. Therm. Eq.

Case 1 0.49 0.6 2.1% 1.6% 36.8% 36.1% 4.8% 5.5% 13.9% 12.5% 96.7% 97.6%

Case 2 0.60 0.65 0.6% 0.7% 37.1% 35.5% 4.9% 5.7% 14.3% 12.3% 99.0% 98.9%

Case 3 0.65 0.65 0.3% 0.4% 37.7% 36.0% 4.8% 5.5% 14.3% 12.7% 99.5% 99.4%

Case 4 0.75 0.65 0.3% 0.3% 37.7% 36.4% 5.3% 5.8% 13.9% 12.4% 99.5% 99.6%

ATR Composition

WGS CompositionAll composition are «dry-base»


Methane ATR – Overall system performances

o Hydrogen production above 7 Nm3/h

o Thermal efficiency approaching 75%o Threshold of 80% easily reachable

RESULTS AND DISCUSSIONNATURAL GAS REFORMING


Natural Gas ATR – Operating conditions

Test parameters

Fuel NATURAL GAS

H2O / O2 / Fuel 0.60-1.00 / 0.55-0.60 / 1

ATR

GHSV 15,000 – 22,500 h-1


Catalyst Shape Honeycomb monolith

WGS

GHSV 2,000 ÷ 3,500 h-1


Catalyst Shape 5 mm Pellets

NATURAL GAS COMPOSITION

CH4 85.249%

C2H6 7.570%

C3H8 1.825%

C4H10 0.561%

C5H12 0.131%

C6H14 0.062%

He 0.102%

N2 4.022%

CO2 0.479%


Natural Gas ATR - Thermal Profiles


WGS O2/Fuel ratio < 0.6

critical for the system

Steam to feed ratio = 0.8 showed highest performances

Results and Discussiuon

Natural Gas ATR – Catalytic Stages Performances

o ATR quite approached equilibrium

o O2/fuel ratio effected performances

o WGS stage far from equilibrium

o Both kinetic and thermodynamic issues

o H2 production quite constant in investigated conditions

H2O/CO

0.78H2O/CO

1.67H2O/CO

0.85H2O/CO

1.17H2O/CO

1.30

Fuel


Natural Gas ATR - Thermal Profiles


WGS Feed rate seems to not

effect temperature profile

System adiabaticity

Heat exchangers well balanced


Natural Gas ATR – Catalytic Stages Performances

o GHSV didn’t effect ATR performances

o Increasing GHSV evidenced WGS kinetic limitations

o H2 production clearly increased with feed rate

o 10 Nm3/h of produced hydrogen achieved

H2O/CO

0.85H2O/CO

0.97H2O/CO

0.96H2O/CO

1.03

Fuel


Natural Gas ATR - Thermal Efficiency

Centralize

d

Distrubuted

Experim

ental Te

st

Catalys

t optimiza

ton0%

20%

40%

60%

80%

70%

63% 68

%

71%

Ther

mal

Effi

cien

cy, L

HV b

ased

GHSV = 15,000 h-1 - H2O : O2 : Fuel = 0.80 : 0.60 : 1

CONCLUSIONS

Conclusions

A compact auto-thermal reforming based fuel processor was designed for hydrogen production from methane and natural gas

Preliminary tests were performed on the system, evidencing:

o System able to sustain very high feed rates

o Good ATR system performances

o Natural gas weakly inhibited ATR catalysts

o Tested WGS catalyst not optimal for the operating conditions

To optimize WGS catalyst

To recover heat from WGS

exhaust stream

System SCALE-UP(50-100 Nm3/h H2)

CON

CLU

SIO

NS

Nex

t Ac

tiviti

es

Acknowledgement

Acknowledgement

The research leading to those results has received funding from the PON 01_02545 “Sviluppo di sistemi per la produzione distribuita di idrogeno e syngas basati su reforming auto termico catalitico multifuel” project.

www.unisa.itAntonio RiccaPhD, Chemical Engineer--------------------------------------------------------------Department of Industrial EngineeringUniversity of Salerno

[email protected]

Thank youfor your kind attention