integrated hydrogen production, purification & … hydrogen production.pdf · integrated...

Integrated Hydrogen Production, Purification & Compression

Demonstration Project

Tony Boyd , A. Gulamhusein, A. Li ( Membrane Reactor Tech. Ltd. )Satish Tamhankar ( Linde North America Inc. )David DaCosta ( Ergenics Corp. ), Mark Golben ( ERRA)

AIChE Spring National Meeting 2010

March 2010 AIChE Spring Meeting2

DOE Project Objectives

Develop an integrated system that directly produces high pressure, high-purity hydrogen from a single unit.

Phase 1:• Task 1: Verify feasibility of the concept, perform a detailed techno-economic

analysis, and develop a test plan (Complete)

• Task 2: Build and experimentally test a Proof of Concept (POC) integrated membrane reformer / metal hydride compressor system (Ongoing)

• POC Performance Targets and Design Basis– Production capacity of 15 Nm3/hr H2

– Hydrogen output pressure of 100 bar

– Hydrogen purity of 99.99%

– Production unit efficiency of >70% and compression efficiency of > 70%

– Unattended operation


Design Basis

Our SystemConventional

Natural GasMethanolGasoline/Diesel

PSA

WaterFuel

Processor Water CompressorPurificationShift

Converter

SyngasH2, CO, CO2, N2

CO2, N2

H2, CO2, N2 H2 (99.99%)

CO + H2O

CO2 + H2

SMR

ATR

POX


PSA

WaterFuel


Converter


CO2, N2

H2, CO2, N2 H2 (99.99%)

CO + H2O

CO2 + H2

SMR

ATR

POX


PSA

WaterFuel


Converter


CO2, N2

H2, CO2, N2 H2 (99.99%)

CO + H2O

CO2 + H2

SMR

ATR

POX

Integrate membrane reformer (MRT) & metal hydride c ompressor (MHC, Ergenics)

• Lower capital cost compared to conventional fuel processors by reducing component count and sub-system complexity.

• Increase system efficiency by:– Directly producing high-purity H2 using high temperature, selective membranes;

increased flux due to suction provided by the hydride compressor

– Improved heat and mass transfer due to inherent advantages of fluid bed design

– Equilibrium shift to enhance hydrogen production in the reformer by lowering the partial pressure of hydrogen in the reaction zone

– Using waste heat from reformer to provide over 20% of H2 compression energy

Natural GasAlternative

Fuels

Hydride Thermal

Compressor

Water FuelProcessor

Compression

CO2, N2

MembraneReactor

Air H2 (99.9999%)

Natural GasAlternative

Fuels

Hydride Thermal

Compressor

Water FuelProcessor

Compression

CO2, N2

MembraneReactor

Air H2 (99.9999%)


Flow Schematic

NaturalGas

Water

ROG

Hydrogen

Vent

Air

Vent

Air

AirComp.

GasComp.

Vapor-izer Fluid Bed

MembraneReactor

Metal HydrideCompressor (MHC) Skid

Fluidized Bed Membrane Reformer (FBMR) Skid


Autothermal Membrane Reformer

Autothermal Fluidized Bed Membrane Reformer (FBMR)

• Autothermal heating (air addition) eliminates need for heat transfer surfaces

• Reformer vessel design uses lower cost metals (carbon steel)

• Novel membrane assemblies ease installation and maintenance

• Fluidized bed greatly enhances mass and heat transfer

Natural Gas

Hydride Thermal

Compressor

Water FuelProcessor

Compression

CO2, N2

MembraneReactor

Air H2 (99.9999%)

Natural Gas

Hydride Thermal

Compressor

Water FuelProcessor

Compression

CO2, N2

MembraneReactor

Air H2 (99.9999%)

NG/Steam

Off-gas

H2

Air


Membranes

New Membrane Design• Membranes operate at 550ºC, 25 barg • Large area, planar membrane modules installed

and tested in multiple runs (6” x 11” x ¼”) with double-sided 25µm palladium alloy foils

• Thinner, higher-flux membranes (15 µm foil) for reduced cost successfully tested in lab

y = 27.076x25um foil

y = 45.97x15um foil

0

10

20

30

40

50

60

0.0 0.5 1.0 1.5∆P0.5 (bar0.5)

H2 pe

rmea

nce

(m3 /m

2 .h)

Natural Gas

Hydride Thermal

Compressor

Water FuelProcessor

Compression

CO2, N2

MembraneReactor

Air H2 (99.9999%)

Natural Gas

Hydride Thermal

Compressor

Water FuelProcessor

Compression

CO2, N2

MembraneReactor

Air H2 (99.9999%)


Burner / Vaporizer / Air Preheater

• Single unit preheats, vaporizes & superheats natural gas – water mixture

• Combustion air pre-heater incorporated around unit reduces overall foot print

• Detailed design effort conducted, including CFD modeling

CFD model shows hot air velocity gradients over exchanger tubes

Natural Gas

Hydride Thermal

Compressor

Water FuelProcessor

Compression

CO2, N2

MembraneReactor

Air H2 (99.9999%)

Natural Gas

Hydride Thermal

Compressor

Water FuelProcessor

Compression

CO2, N2

MembraneReactor

Air H2 (99.9999%)


Reformer Skid

Prototype Design Advantages• Can operate independently from MHC• Greater accessibility• Ideal for component testing and

optimization

Future Generation Optimization• Compartmentalize to reduce classification

zones• Fully integrate with MHC to eliminate

redundant systems & improve efficiency

Installed outdoors at NRC’s Institute for Fuel Cell Innovation (Vancouver BC)

Natural Gas

Hydride Thermal

Compressor

Water FuelProcessor

Compression

CO2, N2

MembraneReactor

Air H2 (99.9999%)

Natural Gas

Hydride Thermal

Compressor

Water FuelProcessor

Compression

CO2, N2

MembraneReactor

Air H2 (99.9999%)

9’ x 6’ footprint12’ high with reactor


Metal Hydride Compressor • Multi-stage metal hydride hydrogen compressor

creates work (pressurized gas) from heat

• Ergenics engineers the composition of hydride alloys to operate at different pressures

• Staging progressively higher pressure alloys lets the compressor achieve very high pressures, using only the energy in hot water

0.0 0.2 0.4 0.6 0.8 1.0 1.20.1

1

10

100

50

5

0.5

25oC

175oC

100oC

40oC

70oC

Pre

ssur

e, A

tm H

2

Hydrogen:Metal Atomic Ratio

Step 1: Low pressure hydrogen is absorbed by an alloy at ambient temperature.

Step 2: Hot fluid heats the alloy causing the hydrogen to be released with an exponential increase in pressure.

27 psi 210 psi

H2 inlet7 psia

H2 output1515 psia

HydrideAlloy

1

HydrideAlloy

2

HydrideAlloy

3

Cold Water

Hot Water

27 psi 210 psi

H2 inlet7 psia

H2 output1515 psia

HydrideAlloy

1

HydrideAlloy

1

HydrideAlloy

2

HydrideAlloy

2

HydrideAlloy

3

HydrideAlloy

3

Cold WaterCold Water

Hot WaterHot Water

Natural Gas

Hydride Thermal

Compressor

Water FuelProcessor

Compression

CO2, N2

MembraneReactor

Air H2 (99.9999%)

Natural Gas

Hydride Thermal

Compressor

Water FuelProcessor

Compression

CO2, N2

MembraneReactor

Air H2 (99.9999%)


Metal Hydride Compressor

Less than 0.5 bara (7 psia) suction

pressure

>105 bara (1,515 psia) discharge

pressure

The next generation system will have a higher level of integration, eliminating the MHC balance-of-plant water heater, fan cooler and c ontrol panel.

Natural Gas

Hydride Thermal

Compressor

Water FuelProcessor

Compression

CO2, N2

MembraneReactor

Air H2 (99.9999%)

Natural Gas

Hydride Thermal

Compressor

Water FuelProcessor

Compression

CO2, N2

MembraneReactor

Air H2 (99.9999%)

MHC skid

FBMR

2 MHC beds

Single MHC stage


System Results (FBMR)

• First round of tests completed– 11 reformer skid runs of varying

membrane loads completed

– System was continuously operated for >425 hours, including one week of unattended operation

• Smooth operation & isothermal membrane zone (~10°C variation)

• FBMR results agreed with model predictions– > 7 Nm3/hr production (without boost from MHC operation)

– Methane conversions of > 60%

• Performance decreased in last run due to partial catalyst deactivation– Found to be trace slip of sulphur through natural gas guard bed

• FBMR conditions stable during integrated system operation– MHC cyclic operation has minimal impact on FBMR temperature and pressure

• Product Purity– Product impurity levels consistent during run (99.9 to >99.99%)

Natural Gas

Hydride Thermal

Compressor

Water FuelProcessor

Compression

CO2, N2

MembraneReactor

Air H2 (99.9999%)

Natural Gas

Hydride Thermal

Compressor

Water FuelProcessor

Compression

CO2, N2

MembraneReactor

Air H2 (99.9999%)


System Results (MHC)

On regulated cylinder H2, suction pressure (2Y axis) varies from 6 psia to 9 psia with each half-cycle.

H2 suction flow rate is nearly constant at 310 L/m.

Outlet H2 is released through a back-pressure regulator, in this case set at the 2nd stage pressure of 210 psia.

Hydride beds are alternately heated or cooled every 50 seconds by a timer.

During integrated FBMR-MHC operation, H2 suction pressure was sub-atmospheric and varied between 8 and 14 psia.

MHC Test 3-10-09

0

100

200

300

400

500

600

5500 5600 5700 5800 5900 6000

Time (s)

Out

let P

ress

ure

and

Flo

w

0

1

2

3

4

5

6

7

8

9

10

Inle

t Pre

ssur

e (p

sia)

Cycle A/B

Inlet Flow l/m

H2 P OUT psia

H2 P IN psia

FBMR & MHC 3-17-09

0

50

100

150

200

18000 18100 18200 18300 18400 18500

Time (s)

Wat

er T

emp

(C)

-5

0

5

10

15

H2

P IN

(psi

a) Cold Water T (C)Hot Water T (C)Timer Hot to AH2 P IN (psia)


Cost Analysis

Using DOE’s H2A analysis for 430 barg H 2 station

• H2A Efficiency (vs. DOE “standard”)– Production efficiency 71% (vs. 63%)– Compression efficiency 75% (vs. 94%)

• Significant MHC efficiency gains possible with improved heat integration or with source of waste heat

– Overall system efficiency of 59% (vs. 62%)• Cost of H2

– $7.98/kg for 100 kg/d, 200 units/year– $3.30/kg for 1,500 kg/d, 200 units/year

• $3.50/kg for “standard” system, 500 units/year)

• Main cost items identified– Longevity of membranes (replacement costs)– Membrane thickness (25 � 15 µm)


Conclusions / Future Work

• Project accomplishments are generally positive • Field test of FMBR and MHC revealed specific paths to achieve predicted

benefits of integration• H2A for integrated system projects competitive H2 cost

Work continues• Two key issues need be addressed before proceeding to the Advanced

Prototype– Improved reliability of hydrogen purity from membranes – Hydride heat exchanger tube integrity

• Prepare skids for future tests– Run both systems independently to confirm issue resolution and then re-run

integrated system

• Finalize design for next generation system (50 Nm3/h)– Optimize heat integration between reformer and MHC to improve overall system

efficiency– Design for manufacture


Thank You!

• Acknowledgements– Funding from the US Department of Energy– Support from NORAM Engineering and Constructors Ltd.

• More Info? Contact us:– MRT: Tony Boyd ([email protected])– Linde: Satish Tamhankar ([email protected])– Ergenics: David DaCosta ([email protected])

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