Materials for the Hydrogen Economy (2007) Episode 5 potx

Boiler w/ stone C276 Dense-Super Heater C276 Solar Cavity Vycor Window Tank Boiler w/ stone C276 Dense-Super Heater C276 Solar Cavity Vycor Window Decomposer Incoloy 800H & aluminide c

Construction materials capable of handling H2SO4 vapor were studied

exten-sively.during.the.early.stages.of.the.S-I.cycle.development,.as.it.was.thought.to.be

the most critical materials.issue of.the cycle Because of.the high

operating.tem-perature involved, materials candidates were chosen from those that derive their

strength from solid-solution strengthening instead of precipitation hardening, as

overage conditions can lead to a decrease in strength Different researchers have

a superheater also made with Hastelloy C-276 At this stage, the vapor begins to.

.catalytic.decompo-sition to take place This decomposer was actually a heat exchanger constructed

Boiler w/

stone (C276)

Dense-Super Heater (C276)

Solar Cavity

Vycor Window

Tank

Boiler w/

stone (C276)

Dense-Super Heater (C276)

Solar Cavity

Vycor Window

Decomposer (Incoloy 800H & aluminide coated 800H tube filled with catalyst pellets)

Condenser (Incoloy 825)

Since the final design and operation conditions of the nuclear S-I hydrogen.

loop are still being finalized, materials of construction development for H2SO4

estimated depth of Corrosion(mil)

fIgure . A schematic and a prototype of a SiC bayonet H2 SO 4 vaporizer/.

decomposer.

fIgure . Zr705.coupon.before.and.after.a.120-h.test.in.HIx.at.310ºC.

Table .

Corrosion rate of various materials in hI x at high Temperatures

Corrosion rate (mm/yr) material boiler (0°C) feed (°C)

Other ceramic materials, such as Al2O3 or mullite, have also been shown to.

Corrosion rate of alloys in h  Po 

alloy Concentration Temperature (°C)

Corrosion rate (mm/yr)

fIgure . A.Ta-10W.coupon.tested.in.HIx-H3PO4.at.140ºC.for.1,209.hours (A).0.h,.(B).

250.h,.(C).874.h.&.(D).1,209.h

4.4.1.3.4 Materials for HI + I 2 + H 2 (Gaseous HI Decomposition)

4.4.1.3.5 Effect of Stress Corrosion and Chemical Contaminants

Corrosion Test results in a vapor medium of hI–I  –h  o (//) vapor at

various Temperatures for ,000 h duration

125°C has been successfully demonstrated (figure.4.22) The permeability or flux.

Corrosion.products.from.other.sections III H3PO4.concentration H2SO4.and.HIx.from.Section.I.and.iodine.

separation.

Corrosion.products.from.other.sections III HI.distillation.(reactive.and.

O–HI.gaseous.mix-ture at elevated temperatures (figure.4.24) A separation factor of more than 600.

fIgure . Schematic.of.the.electro-electrodialysis.process.to.concentrate.the.HIx acid.

feed.from.the.Bunsen.reaction.

Te mp (°C)

H 2 /H 2

S1 S2 S3 L2 L1

a

0 100 200 300 400 500 600 700

b fIgure . Separation.factor.of.H2 from.H 2 -HI-H 2 O.for.various.silica.membranes.

... sulfuric acid decomposition

Fe 2 O 3

CeO 2

Al 2 O 3

NiO

fIgure . Relationship.between.conversion.to.SO2 +.H2O.and.temperature.for.catalytic.

metal.oxides.and.Pt.in.a.N2.flow.containing.4.mol%.SO3.at.a.space.velocity.of.4,300.h.

1 Miyamato, Y et al., R&D program on hydrogen production system with high

tem-perature cooled reactor, in International Hydrogen Energy Forum, Vol 2, Munich,.

Germany,.2000,.pp 271–278.

2 Brown, L.C., Funk, J.F., and Showalter, S.K., Initial Screening of

Thermochemi-cal Water Splitting Cycles for High Efficiency Generation of Hydrogen Fuels Using

3 Brown,.L.C.,.Besenbruch,.G.E.,.Lentsch,.R.D.,.Schultz,.K.R.,.Funk,.J.F.,.Pickard,.P.S.,.

Marshal, A.C., and Showalter, S.K., High Efficiency Generation of Hydrogen Fuels

10 High Efficiency Hydrogen Production from Nuclear Energy: Laboratory

11 Sakurai, M., Nakajima, H., Onuki, K., and Shimizu, S., Investigation of two liquid.

phase separation characteristics on the iodine-sulfur thermochemical hydrogen

pro-duction.process,.International Journal of Hydrogen Energy,.25,.605–611,.2000.

14 Trester,.P.W and.Staley,.H.G.,.Assessment and Investigation of Containment Materials

for the Sulfur-Iodine Thermochemical Water-Splitting Process for Hydrogen

20 Porisini,.F.,.Selection and.evaluation of materials.for the construction of a pre-pilot.

plant.for.thermal.decomposition.of.sulfuric.acid,.International Journal of Hydrogen

26 Wong,.B.,.Brown,.L.C.,.and.Besenbruch,.G.E.,.Corrosion Screening of Construction

high.temperature,.Journal of Membrane Science,.267,.8–17,.2005.

34 Nomura, M., Kasahara, S., Okuda, H., and Nakao, S., Evaluation of the IS process.

featuring.membrane.techniques.by.total.thermal.efficiency,.International Journal of

H2SO4.and.production.of.HBr.by.the.reaction.of.SO2.with.Br2.and.H2O,.International

39 Ballinger,.R.,.The.Development.of.Self.Catalytic.Materials.for.Thermochemical.Water.

Splitting.Using.the.Sulfur-Iodine.Process,.paper.presented.at.the.UNLV-HTHX.quar-terly.meeting,.Univerity.of.Nevada,.Las.Vegas,.December.5,.2005.

for Photobiological Hydrogen Production

Daniel M Blake, Wade A Amos, Maria L Ghirardi, and Michael Seibert

ConTenTs

5.1 Introduction 123

5.2 Description.of.the.Process 124

5.2.1 Oxygen-Tolerant.Hydrogenase.Systems 126

5.2.2 Anaerobic.Hydrogenase.Systems 127

5.3 Reactor.Materials 129

5.3.1 Photobioreactors 130

5.3.2 Photobioreactor.Materials 131

5.4 Economics.and.Cost.Drivers.for.Photobiological.Hydrogen.Production 135

5.4.1 Operating.Costs 135

5.4.2 Capital.Costs 137

5.4.3 General.Design.Considerations 138

5.4.4 Case.Study 139

5.5 Conclusion 140

Acknowledgments 140

References 140

. InTroduCTIon The.world’s.energy.infrastructure.is.under.pressure.from.rapidly.increasing.demand

Recent.worldwide.events.have.increased.public.anxiety.about.the.cost.of.gasoline

and.heating.fuels,.and.the.security.of.these.resources.has.become.an.issue Finally,

the.amount.of.pollution.and.CO2.that.society.is.generating.is.increasing,.and.every-

one,.from.individual.villages.to.entire.countries,.is.looking.for,.or.should.be.look-ing.for,.a.sustainable,.secure.energy.system Currently,.the.world.has.over.6.billion

individuals,.all.powered.by.solar.energy The.food.we.eat.and.the.oxygen.we.breathe

come.from.photosynthesis Can.energy.from.the.sun,.which.indirectly.powers.all

animal.life.on.the.planet,.including.ourselves,.also.give.us.hydrogen.from.water.to

be.used.as.a.renewable.energy.carrier?

This.review.will.discuss.the.development.of.photobiological.hydrogen.produc-tion processes, where microorganisms (algae or cyanobacteria) funcThis.review.will.discuss.the.development.of.photobiological.hydrogen.produc-tion as living

as starch molecules (the normal function of photosynthesis), these organisms can.

recombine.the.protons.and.electrons.and.evolve.H2.gas.under anaerobic conditions

1 The.hydrogenase.genes.in.green.algae.and.in.some.cyanobacteria.are.not.

2 The.expression.and.function.of.the.genes.that.catalyze.the.assembly.of.the

catalytic metallocluster of the algal [FeFe]-hydrogenases require

Maness, personal communication) The second approach involves the manipulation

of green algal physiology to induce culture anaerobiosis, expression of the

Redox Chemistry

(water oxidation produces O 2 , electrons and a proton gradient across the chloroplast membrane through an electron- transport- facilitated reaction)

CO 2 fixation

CO 2 + e - + ATP starch (ATP is obtained in a coupled dissipation of the

H + gradient by the ATP synthase) + O 2

H 2 gas production

2 H + + 2 e - H 2 (catalyzed by the hydrogenase enzyme) fIgure . Representation.of.the.major.steps.required.for.photosynthetic.CO2 fixation.

(upper.right.box).and.hydrogen.production.(lower.right.box).