\tL !£. \£L\ \H ^ * i i 4 < % B •**••*•%• isv I iT% § i <f|

SYSTEMS DESIGN INSTITUTE | .NASA GRANT NOT MJOS-I 1 I &ew • V B I

>H2HH2H2

IYJ

'-//7*/

ENERGY!

\/<"M I I 41 C T

A HYERCGEN ENEEGYCAFR1EB. VOLUME 1: S U M M A R Y (HoustonUniv.) 27 p HC $3.50 CSCL 20M

ZH2H2H2H2HI2H2H2H2H2H2H2H2H2i2H2H2H2H

N7«-11727

UnclasG3/33 4,-V-*."

UOI4O14OUOUOUOUOONIVERSITT OF HOUSTON I • (I JOHNSON SPACE CENTERi • RICE UNIVERSITY i

JILJOUILJO«J JF iunii jr Swwfi Ji msam JP ouo

https://ntrs.nasa.gov/search.jsp?R=19740003614 2018-06-25T16:42:05+00:00Z

A HYDROGEN ENERGY CARRIERVol. I - Summary

SEPTEMBER, 1973

Editors:

Robert L. Savage

Lee BlankTom CadyKenneth CoxRichard MurrayRichard Dee Williams

'C. J. Huang, Co-DirectorUniversity of Houston

John R. Howell, Associate DirectorUniversity of Houston

Joel J. Hebert, Assistant DirectorRice University

Barbara K. Eandi, Co-DirectorNASA-Johnson Space Center

W. Richard Downs, Technical DirectorNASA-Johnson Space Center

SUMMARY

Hydrogen as an energy carrier is almost ideal froman environmental viewpoint. It is made from waterand its product of combustion is water. Hydrogencan be used as a fuel in all conventional areas ofenergy use, including industrial chemical, industrialfuel, electric power generation, residential andcommercial, and transportation. A primary sourceof energy such as fossil fuel, nuclear energy or solarenergy must be used to produce hydrogen. The costof hydrogen will depend on the cost of the primarysource of energy and the efficiency of the processused to produce the hydrogen. Projected costs ofgaseous hydrogen at the producing plant rangefrom $1.00 to $3.00 per million Btu. Pipeline trans-mission of gaseous hydrogen will add only a fewcents per million Btu to the cost of hydrogen fueldelivered to the customer.

Initial large scale methods of production of hydrogenwill be from the gasification of coal with costs fore-cast to drop from over $1.50 per million Btu to as lowas $1.00 as the technology develops. Coal, by farthe greatest domestic energy reserve, can be gasi-fied to produce substantial amounts of hydrogen formany years. Coal will also be used to producesynthetic natural gas and synthetic crude oil. Be-cause of the potentially high demand for coal bythese competing forms of fuel, nuclear energy willalso be 'used to produce hydrogen. The establishedprocess is by electrolysis of water but the overallefficiency is low. Depending on the cost of electricpower, the cost of hydrogen gas produced by elec-trolysis will range from $1.00 to $5.00 per millionBtu. There is very little cheap power available, evenat off-peak periods and the cost of most of thehydrogen produced by electrolysis will be from $3.00to $5.00 per million Btu.

If the needed technology is developed, direct ther-mal decomposition of water or thermo-chemicaldecomposition of water to produce hydrogen, usingnuclear heat rather than electricity, will producehydrogen at a cost of $1.00 to $1.50 per million Btu.These processes are not expected to be operationalbefore 1985. For the period after the year 2000,solar energy may replace nuclear energy for theproduction of hydrogen from water, but the cost isforecast to be in the range of $2.00 to $3.00 permillion Btu.

Hydrogen can be transported most economicallyby pipeline. Special attention must be directed todesigning the pipeline to avoid conditions which may

cause hydrogen environment embrittlement. Thiscan be done.

There are no non-technical aspects of the hydrogeneconomy which cannot be met. Safety problemswith hydrogen are similar to and probably no worsethan safety problems with other hazardous fuels.Environmental, social, legal, economic and politicalfactors have been examined. No insurmountableproblems are anticipated in converting to a hydrogeneconomy.

Implementation of hydrogen as an energy carrierinto our energy system must be by integrated steps.Although large tonnages of hydrogen are "used inthe chemical industry, there is no established marketfor hydrogen as a fuel, except in the space program.We believe that direct experience in the production,pipeline transportation, and use of hydrogen as anenergy carrier is needed to demonstrate its feasi-bility for use in the nation's energy system. Our con-cept is that a demonstration project is needed toestablish the technology of producing hydrogen byone of the proposed methods and transporting itby pipeline to a consumer located in a high pollutionarea where it would be advantageous to burn a cleanfuel. A Ford foundation grant or.government subsidyto pay the difference between the cost of hydrogenas a fuel and the cost of a conventional fuel wouldbe needed to give the successful bidder a guaranteedmarket for several years. During this time he wouldbe permitted and encouraged to develop other mar-kets. In order to get maximum involvement by indus-try, no other government participation would beneeded for this 'Hyplex' project.

Subsequent projects might be a new city (Hycity),operation on hydrogen fuel, or even an entire islandsuch as Hawaii. Final integration of hydrogen fuelinto the energy system would be the result ofeconomic and environmental advantages.

The authors of this report were under no commit-ment or incentive to present a particular point ofview. They were assembled as Summer FacultyFellows to do a systems analysis study. This reportis the result of their work during the summer. Somepositions or conclusions reported by other authorshave been supported whereas other positions orconclusions have been critically questioned. Thissummary report may be utilized as an overviewdocument by the decision makers who must dealwith the energy problem. Complete details of resultspresented here may be obtained in Volume II -Systems Analysis.

ORIGINAL PAGE ISOF POOR QUALITY

OVERALL ENERGY PICTURE

This work is related to the current energy shortagein the United States. Inadequate supplies of oil andgas, coal in the wrong form or restricted in use anddelayed nuclear energy projects contribute to thisshortage. A lasting shortage or even a temporarilyinterrupted supply will have a devastating impactupon the nation's economy, its standard of living,and its defense posture. These are large stakeswhich must be preserved by positive correctiveactions. It is this demonstrated need for energywhich provides justification for this report; an inde-pendent report on hydrogen as an energy carrier.

The Fossil Fuel Cycle

The present energy shortage is the result of a com-bination of economic, environmental and politicalfactors which are affecting the supply and use offossil fuels as a source of energy. In the fossil fuelcycle (Figure 1), two aspects should be noted; thetime scale, and the environmental impact. It takesmillions of years for the vegetation to be convertedto fossil fuel, which results in depletion of the fuelat the rate we now use it.

NASA-S-73-2430

(ADAPTED FROM FORTUNE)

Figure 1. Fossil Fuel Cycle

Undesirable environmental effects occur at mostpoints in the cycle. In the fossil fuel cycle, coal,oil or gas is burned at the point of use to produceheat energy which may be converted to usefulmechanical energy or electrical energy. Air is usedto supply the oxygen needed for combustion of thefuel and the products of combustion (carbon diox-ide, carbon monoxide, water, sulfur oxides, nitrogenoxides, hydrocarbon emissions and/or particulatematter) are returned..to the atmosphere at the pointof use. The undesirable materials become pollutants

and, depending on the concentrations, may causeminor or major problems.

A Hydrogen Fuel Cycle

In the hydrogen fuel cycle (Figure 2) the main prod-uct of combustion, water, returns to the sea in arelatively short time. The conversion process mayhave some undesirable emissions, but their impactcan be minimized by locating the conversion plantin a remote area. If air is used instead of oxygenfor the combustion of hydrogen, some minor amountsof nitrogen oxides may be formed as pollutants, buteven in this case the total pollution would be greatlyreduced compared to that from fossil fuels.

NASA.I.T1.149*

(ADAPTED FtOM FORTUNE)

Figure 2. Hydrogen Fuel Cycle

Figure 2 illustrates a significant concept which mustbe emphasized. Hydrogen is not a primary source ofenergy. It can be formed from water only if one ofthe primary sources of energy—fossil, nuclear, orsolar—is used in the process.

The Demand for Energy

A great portion of the energy used in the United->States is obtained from the fossil fuel sources ofcoal, natural gas or liquid hydrocarbons. Historically,these fuels have been cheap, because, in relationto some other sources of energy, they are easy toobtain. Cheap, not so much because you can pickthem up off the ground, but, because technology hasbeen directed at their recovery and use. However,our supply of these fuels is waning since their forma-tion rates are so very slow in comparison to ourusage rates. Because there are several forms offossil fuels and because we use them for so manydifferent purposes, the energy system becomescomplex (Figure 3).

ORIGINAL PAGE ISOF POOR QUALITY

SUPPLY

OEOTHERMAL .01 (-%

HYDROELECTRIC 2.6 (4%)

NUCLEAR .2 (.3%)

USERS

ELECTRIC POWERGENERATION

-1 », NATURAL'•'--, 221 (33%)

NASA-S-73-2569

4.1

(All VALUES ARE x 10>S BTU - TOTAL U.S. DEMAND 67.8 x 1015 BTU)

Figure 3. U. S. Energy Demand Patterns, 1970

The 68 quadrillion (68 Q) Btu expended in 1970 is.an astronomical amount which, if considered in theoil equivalent of 33 million barrels per day, is equalto thejflow over Niagara Falls every 15 minutes.

^3Not very impressive? Well, remember, this oilequivalent must be mined or drilled for, shipped,refined, distributed and be supplied a place to burn.Most of these intermediate processes pollute insome way, thus adding to the complication. Evenwith all of this complication the costs of these pol-luting fuels has been low, thus allowing the develop-ment of convenience devices now considered essen-tial to our way of life.

Previous authors have used a variety of techniquesto forecast the future of the energy demand picture.Many of these, following the historical growth pat-terns of the past, have projected with no allowancefor the now obvious limit which must exist for theindividual energy consumer. This limit does exist dueto the time and spatial constraints placed on each ofthese energy consumers. We refer to this limit assaturation. The time restraint component of satura-tion implies that, even though each person mayperform many activities each day, only a few maybe engaged in at one time. Thus, the energy ex-pended in a day has some average upper limit. Thespatial constraint restricts the use of energy percapita, since only so much space is needed to per-form any of these many activities. Even if conditionswere such that the use of energy was maximized,only this limited amount can be expended. By theforecasting of the time and space required foractivities, a maximum energy use per capita (satura-

tion) may be established and utilized for demandforecasting.

When the saturation concept was not applicable forper capita projection, we used the forecasts ofenergy demand indicators such as gross nationalproduct and adjusted historical growth rates. In allthese forecasts the effects of population growth areevident. The population growth rate is projected atone percent, resulting in a total population in theUnited States of 270 million in 2000 and 328 millionin 2020.

Total demand forecast was obtained by the compo-sition forecasting method in which each energy usearea was forecast separately then summed. Areasfor the study reviewed below are:

residential and commercialindustrial-fueltransportationelectric power generationindustrial-chemical

The future of the saturation energy picture is adefinite indicator that conservation is not only nec-essary, but that it will be practiced—whether welike it or not. Consequently, in each use area aconservation picture is presented. These conserva-tion measures are not the result of doing withoutenergy, rather the wiser use of energy. We believethese conservation demand projections to be thefuture of energy demand, since they representreasonable, livable efforts to conserve the energywe are able to obtain for this country.

FUTURE DEMAND BY USE AREAS

Residential and Commercial

The residential and commercial use area represents23 percent of the 1970 energy market. Over three-fourths of this amount is used for space heating,water heating, cooking and refrigeration. Most of theenergy is obtained from fossil fuels (85 percent inresidential and 65 percent in commercial) and thebalance from electricity. Due to recent upsurges inair conditioning and other comfort items, the yearlygrowth rates of this area have been high; 2.7 percentfor residential and 3.7 percent for commercial.

A saturation limit of 400 million Btu per year perhousehold is expected to be reached by 1985. Thiswill allow complete space conditioning and a pro-liferation of appliances in all households. Due to theincreased services needed for the populace and avigorous competitive market, commercial energyuse is expected to grow at 3.5 percent per year.

Conservation in residential and commercial will bepracticed by increased use of insulation and im-proved design, all of which will reduce thermal lossesof the structure, resulting in an eventual 25 percentsavings in energy. The major energy using devicesin this area can be expected to be improved so that,by 1985 their efficiency will be from 10 percent to25 percent greater. The saturation and conserva-tion forecasts for the individual areas of residentialand commercial are depicted in Figure 4. Note that,even though most of the conservation measures arelong term, an approximate 25 percent savings ofenergy is possible by the year 2000.

DEMAND, 1015 BTU60

TOTALCOMMERCIALRESIDENTIAL

COMMERCIAL

RESIDENTIAL _TOTAL

SATURATIONCONSERVATION

o ACTUAL DATA

Industrial - Fuel

The use of fossil fuels for direct heating and steamgeneration and the use of electricity for heating andmechanical drive is the energy use area ofindustrial-fuel. Some of the principal sectors of thislargest user of energy (30 percent of total) are listedbelow:

primary metal industrieschemicals and allied productspetroleum refining and related industries.

The common fossil fuels, plus electricity, are theenergy suppliers for the area, however, almost one-half (47 percent) of the energy is supplied bynatural gas. Due to the environmental restrictionsand greater effort to obtain raw materials, thehistoric decrease in energy input per unit output hasseen a reversal in trend. It is anticipated that futureincreases in efficiency will overtake this short,present-term trend toward increased energy per unitoutput.

If allowed to, the uses of energy in this area areexpected to grow at a rate of 3 percent per year.The higher-than-saturation growth rate is anticipateddue to the need for new products, population growthand necessary replacement of presently..- ownedgoods. However, conservation will result from moreefficient equipment, better maintenance policies andearly replacement of. old equipment. Overall, a 10percent savings is anticipated in the industrial-fuelarea. Total saturation and conservation projectionsare presented in Figure 5.

DEMAND, 1015 BTU

1970 1980 1990 2000 2010 2020YEAR

Figure 4.Residential and Commercial Demand, 1970-2020

1970 1980 1990 2000 2010 2020YEAR

Figure 5. Industrial - Fuel Demand, 1970-2020

MttftAL PAGE S3QUALITY

Transportation

Although the transportation area is the most visibleof all energy users, it is not the largest. Twenty-fourpercent of all the energy is spent in the operationof private and commercial passenger traffic, com-mercial freight systems and other transport facilitiessuch as agricultural, construction and recreational.The decentralized style of living, working and play-ing in this country is the major reason for the historic4 percent annual growth rate of energy use in thisarea.

A time restriction in the saturation concept is evidentin this area. The present use of the automobile(approximately one hour per day per capita) isevidence that some future limit must exist, since itis not possible to drive more than an average ofseveral hours a day and still perform all the otherfunctions necessary to life. On the other hand,.sincethe automobile and truck have become such anintegrated unit of our transportation and life stylesystem, it is unlikely that radical shifts from thispattern will occur in the near future. Projection of alimit to the per capita energy used in transportationallows the saturation curve of Figure 6 to be made.

travel, which presently represents two-thirds of allautomobile mileage. The commercial freight traffic,presently 27 percent of the transportation energymarket, may be expected to conserve energy byshifting to more efficient modes, thus reducing itsenergy use by 50 percent. The popular and, thus far,economically favorable strategy of multiple ship-ment of goods during the manufacturing processescan be expected to disappear as the cost of fuelincreases. The rather substantial energy savingsmade possible by these realistic conservation movesare reflected in the conservation curve of Figure 6.

Electric Power Generation

Since the electric output of the electric generationindustry has already been accounted for within theother user areas, the electric power generation areaherein will be defined as the remaining 69 percentof the input energy, or that energy which shows upas rejected heat. The relationship between totalelectric energy, electric, power generation and theuser areas is portrayed in Figure 7. A total of 83

NASA-S-73-2495

1970 1980 1990 2000 2010 2020

YEAR

Figures. Transportation Demand, 1970-2020

Conservation in this area is not only necessary, butthe results are quite favorable. The use of car poolsand mass transit facilities are worth considering. Aprojected change in transportation habits such that20 percent of the travel would be by single occu-pancy autos, 40 percent by multiple occupancy and40 percent by some mass transit form, would resultin an 11 percent fuel savings by 1990. The use ofmore economically sized autos will allow a 33 per-cent savings in auto fuel use. Additional savings arepossible with reasonable shifts in non-employment

TOTAL ENERGYFOR ELECTRIC

GENERATION ANDDISTRIBUTION

ELECTRICPOWER

GENERATION

NOTE: ALL ENERGY VALUES X 10" BTU

Figure 7. Electric Demand Pattern, 1970

percent of the energy utilized to produce electricityis derived from fossil fuel sources. The demand forthis electrical energy in the user area has grownrapidly in the past (7 percent per year), due to itsconvenience and active promotion. Because theconsumer determines the needs in the area of elec-tric power generation, the user areas define thefuture needs for generation. Presently 16 percent ofresidential energy needs are supplied by electricity.This is expected to grow to 30 percent by 1985 and36 percent by 2020. The commercial and industrial-fuel, uses of electricity are projected at the antici-pated annual growth rates of 3.5 percent and 3

percent respectively. Summation of the demands forthese use areas results in the saturation projection.ofFigure 8.

DEMAND,

1970 19(0 1990 2000 2010 2020YEAR

Figure 8.Electric Power Generation Demand, 1970-2020

The carry-over effect of conservation in the electricuse areas is to be quite effective in the conservationof energy for electric power generation. The con-servation curve of Figure 8 accounts for 50 percentof the savings due to residential and commercialuse and 10 percent savings is possible. Anotherpotential area of conservation, not reflected here,is the use of heat rejected from the generationprocess, that is, an increased use of the electricpower generation energy, after it is used for genera-tion.

Industrial - Chemical

The industrial-chemical area, not a true demand forenergy in the usual concept, is the use of fossil typematerials as raw materials in the production ofgoods. Some of the more common products areammonia, road tars, plastics and resin materials.The rapid growth of 6 percent per year in the recentpast has resulted from the many new products fromthese fossil materials.

Saturation considerations in this area anticipate thatthis growth rate will decrease to 3 percent annuallyby 1985. Since these uses are so important to thecountry, conservation measures will reduce thisgrowth to 2.5 percent by 1985. Saturation andconservation projections are presented in Figure 9.

ORIGiNAL PAGE ISOF POOR QUALITY

NASA-S-73-2418

1970 1980 1990 2000 2010 2020YEAR

Figure 9. Industrial - Chemical Demand, 1970-2020

It is now possible to observe the total future demanupicture for the five user areas. Total saturationdemand is presented in Figure 10, while the morerealistic conservation curve is in Figure 11. Com-

DEMAND, 1015 BTU300

250

TOTALSATURATION

DEMAND-

TRANSPORTATION-

INDUSTRIALCHEMICAL

1970 1980 1990 2000 2010 2020YEAR

Figure 10. Total Saturation Demand, 1970-2020

NASA-S-73-2503

1970 1980 1990 2000 2010 2020YEAR

Figure 11. Total Conservation Demand, 1970-2020

parison of these indicates that, in contrast to theexponential projections which forecast that in theyear 2000 the energy demand will be 3.2 times the1970 demand, the saturation concept forecasts thatthe demand in 2000 will be only 2.8 times the 1970demand. Conservation measures can reduce thisneed to 2.0 times the 1970 figure. This is still asizable increase in energy needs in the next 30years; however, the 26 percent savings in 2000may well be one of the factors that allows us tomeet our future energy demands—to meet them andstill live comfortably.

Why Hydrogen?

Hydrogen fuel may be able to play an important partin the transition period from a fossil to a predomi-nantly nuclear energy economy. Based on presentand projected technology, nuclear energy will berestricted largely to the generation of electricity andvery large-scale heat energy. There is little antici-pated use for nuclear energy for transportation,residential and commercial uses, other than in theform of electricity. Abundant supplies of hydrogenproduced from fossil fuels, nuclear energy or ulti-mately from solar energy can provide the muchneeded flexibility and environmental acceptabilityneeded in our economy.

As a result of its importance as an industrial gas,much work has been done during the past fifty yearson methods for producing and handling hydrogen.The early use of hydrogen to make ammonia forfertilizers and munitions firmly established hydrogenas an important industrial gas for chemical andmetallurgical uses. More recently, we have usedlarge quantities of hydrogen as a high energy fuel forspace travel. In these cases hydrogen has beenproduced primarily from fossil fuels because thesewere the lowest cost methods. With future limitationsin the supply of fossil fuels becoming apparent andwith the virtual certainty that the fossil fuels will costmore, other methods for making hydrogen are beinginvestigated. An additional incentive to producehydrogen in large quantities is the need for a cleanburning fuel burning to help protect our environment.

How We Will Use Hydrogen

Putting hydrogen's energy to use appears to be arelatively easy task. Industry now uses hydrogen innumerous chemical and manufacturing processes;enlargement of this market poses no insurmountabletechnical problem. This does not mean, however,that significant problems do not exist, or that carefulplanning and extensive research will not be needed.

Hydrogen functions in two modes, as a chemical

and as a fuel. Chemically it serves as an input toprocesses for making ammonia, methonol, plastics,synthetic rubber, lubricating oils, and several otherproducts. Present hydrogen input to these processesprimarily comes from a synthesis gas plant thatconsumes natural gas or naptha. A pipeline hydro-gen from other sources into these chemical pro-cesses will allow normal operation while reducingour petroleum and natural gas requirements by aboutthree percent.

Present fuel uses for hydrogen are rather limited;however, they include welding or cutting of metals,iron ore reduction, and space vehicle propulsion.This does not mean that hydrogen is a poor fuel,only that it is not available at competitive pricescompared to other fuel forms.

Hydrogen is an excellent fuel for most applications.It has extremely wide flammability limits and a veryhigh energy density when viewed on a mass basis.The wide flammability limits allow hydrogen aircombustion over large ranges of fuel-air ratio, lead-ing to stable flame conditions, flexibility in design ofthe usage device, and avoidance of nitric oxideemission.

The high energy density facilitates constructionof high power low weight devices such as rocketsand aircraft. These devices, however, will inherentlybe large in order to carry the required fuel volumefor reasonable duration of operation.

The favorable combustion characteristics allow notonly conversion of present furnaces, heaters, andappliances, but also provide flexibility for novel newdesigns. With proper precautions, all existent devicesthat burn fossil fuel can be converted to burn hydro-gen without loss of effectiveness or efficiency.

New flame-type furnaces can be designed ventless,thereby eliminating all stack heat losses, which canbe as high as 40 percent of the fuel energy. Sincethe exhaust from such a device will contain onlywater, excess air and traces of oxides of nitrogen(NOx), the combustor can be vented directly intospace to be heated. Condensation and collection ofexcess water in the liquid form can provide auto-matic humidity control, while lean fuel-air ratiocombustion can provide control of NOx to acceptablelevels.

A second new heating device that shows promise isthe catalytic converter or burner. Hydrogen ispassed over a catalyst in the presence of air,resulting in flameless low temperature combustion.

Since the combustion temperature is less than1750K, NOX is not formed in measurable quantities,eliminating the last harmful chemical product in theexhaust. Prototype catalytic ranges and spaceheaters have been built; such devices, however,are still considered to be in the research state. Costand availability of catalytic material may delay theintroduction of practical devices on the market.

The water modified hydrogen-oxygen (aphodid)burner (see Figure 12) may provide a way to increasebasic steam power plant efficiency from about 40percent to as high as 60 percent. These high effi-ciencies may be possible since hydrogen-oxygencombustion temperatures can peak at 3080°K. Aturbine incorporating cooled blading may be able toutilize this higher temperature or selected lowertemperatures as modified by water injection into theburner. The device does, however, require a supplyof oxygen which will, in turn, require site locationnear an oxygen supply point.

ORIGINAL PAGE ISOF POOR QUALITY

NASA-S-73-2584

Figure 13. Pratt & Whitney RL10 Engine

NASA-S-73 -2SB2

NASA-S-73 2466

EXCESS WATER Figure 14. Pratt & Whitney J-57 Engine

Figure 12.

Water Modified Hydrogen - Oxygen (Aphodid) Burner

N»SA-S-73-JSli

In recent years the operation of nearly every type ofinternal combustion engine using hydrogen has beensuccessfully undertaken; rocket engines as in Figure13, jet engines as in Figures 14 & 15, reciprocatingengines as in Figure 16. Wankel and other engineshave utilized hydrogen as a fuel. None of thesedevices have operated for the extended periodsneeded to prove reliability, however feasibility hasbeen established. Not only do these engines havefavorable performance characteristics but also theyare virtually emission free. Only NOX is present andit appears that even this contaminant can be con-trolled to acceptable limits by mixture control. Figure 15. Pratt & Whitney 304 Engine

PAGE ISQUALITY

Figure 16.Oklahoma State University Hydrogen Fueled Engine

Fuel cells (See Figure 17) and magnetohydrody-namic generators appear to remain in the researchand development stage for the foreseeable future.Should breakthroughs occur such that these devicesbecome reliable and economic, they can be easilyintegrated into a hydrogen fuel system.

From a fuel usage standpoint, industry appears to betotally convertible to hydrogen. Furnaces, steamgenerators, process heaters and stationary internal-combustion engines now in use can be progressivelycoverted to hydrogen or replaced by new hydrogenfueled equipment. As hydrogen becomes availableas a fuel, this area of usage would appear to be thefirst to adapt.

The safety and economics considerations of change-over from fossil to hydrogen fuel are probably bestunderstood and manageable in the industrial sector.Flexibility and adaptability are vital in an industrialenvironment. These factors, which have allowedindustry to survive in a highly competitive marketplace, will also allow an open minded evaluation ofa promising new source of energy in a society thatis vulnerable to energy shortages. Since industrytraditionally is the first sector required to shut downin an energy deficient region, one that has a multi-fuel (hydrogen-natural gas, hydrogen-oil) capabilityretains a decided competitive advantage.

In highly industrialized urban areas, conversion froma fossil based fuel to hydrogen may be more eco-nomical than installing and operating the alternativeair pollution control equipment. The cleanliness of

WATER

H2

\

N

POROUSHYDROGENELECTRODE

(ANODE) —

t

1̂

iX

I

I5"~

I

Tc

>̂t11

_J

)2+H2O

f 1— POROUS

OXYGENELECTRODE

ELECTRICALINSULATION

HYDROGEN

OXYGEN

Figure 17. Hydrogen - Oxygen Fuel Cell

hydrogen may allow reclamation and growth inindustrial areas now facing restrictions in operationby the Environmental Protection Agency.

The most severe difficulties of implementation of thefuel hydrogen appear to lie in the transportationsector. On-board storage of sufficient hydrogenenergy to provide adequate range appears imprac-tical in most mobile applications in spite of the factthat hydrogen has a very favorable energy density ona weight basis. (See Figure 18). Cryogenic liquid,high pressure gas, and metallic hydrides all haveundesirable size and weight configurations forreasonable operational range of surface vehicles. Allof the above pose unrealistic economic problems tothe private transportation sector. The hydrogenfueled automobile or truck appears therefore, to beunrealistic within the near future.

continue to be fossil fuels. It is unlikely that thepresent gasoline-like motor fuel will be replaced byany synthetic fuel, including hydrogen, for at leastthe next two decades. When fossil sources are nolonger available, other synthetic fuels such asmethanol, or ammonia (derived from hydrogen) mayprove desirable alternatives to hydrogen.

The cost and complexity probably will preclude anysignificant change-over of the existing residentialand commercial sector to hydrogen. Even thoughfurnaces and appliances can be converted readilyfrom natural gas to hydrogen, the combined cost ofthe conversion of all appliances, as well as the fuelsupply system (meters, pipes, etc.), will preventlarge scale conversion of existing systems. In con-trast, however, newly constructed developmentslocated near a source of hydrogen can easily use

SO

40

ui o 30O •—

oeeiu

10

D MASS ENERGYDENSITY

VOLUME ENERGYDENSITY

GASOLINE REFERENCE

METHANOL AMMONIA HYDROGENGASOLINE(ISO-OCTANE

C8H18>

PROPANE(LPGC3H8)

METHANE(LIOCH4)

(CH3OH) (LIO NH3) (LIO H2)METAL

HYDRIDEMg2N;-Hx

ADVANCEDBATTERIES*(No-S, Li-S)

25

20

15 2

13"l!

•INCLUDES ADJUSTMENT FOR DIFFERENT ENERGY CONVERSION EFFICIENCY

Figure 18. Energy Density Characteristics of Various Transportation Fuels

The liquid hydrogen fueled commercial airplane, onthe other hand, may present a more optimistic pic-ture. Because aircraft are weight rather than volumesensitive, a slightly larger, but lighter, aircraft maybe able to carry a larger payload with less grossweight at takeoff than its fossil fueled counterpartof the same range. This is possible due to the veryhigh energy to weight ratio of hydrogen. Preliminarystudies indicate that liquid hydrogen fueled transportaircraft may be economically and technically feasi-ble.

Future fuels for surface transportation probably will

this new fuel. Here the cost of implementation shouldnot exceed that for a comparable natural gas systemin an energy scarce area. In this case, local airquality would be protected.

The second most optimistic sector for introductionof hydrogen into our economy is the electric powergeneration field. Where fossil resources are used inclose proximity to a degrading urban atmosphere,hydrogen could be employed with a less harmfulimpact. Not only can present steam power plantsbe converted to hydrogen, but future plants can be

10

designed specifically for hydrogen at an increase inefficiency. Assuming an available supply of oxygenfrom the hydrogen generation facility, the previouslydescribed aphodid burner could be employed. Con-version (thermal) efficiencies up to 60 percentappear feasible for this system. No significanthandling or safety problems are foreseen, since theelectric power generation sector has used hydrogenfor years as a coolant in its large turbo-generators.

Society's ability to utilize hydrogen as it becomesincreasingly available appears certain. This analysisindicates that the order of priority for conversion

should proceed as follows:

industrial-chemical,industrial-fuel,electric power generation, andresidential and commercial.

Such a plan should maximize the use of hydrogenand minimize the use of fossil sources whenever achoice of fuels must be made. This would result in amaximum availability of fossil sources to thoseareas, such as surface transportation, that cannoteffectively use hydrogen.

11

The production of hydrogen from fossil fuel suppliesand water has been examined in detail. Hydrogencan be produced from either of these sources. How-ever, in the production of hydrogen from water, aprimary source of energy, such as nuclear, solar,wind, fossil or other energy form, is required.

Hydrogen is used today as a chemical intermediatein the chemical industry in the amount of 3 trillionstandard cubic feet per year (3 x 1012 scf/yr). Mostof this hydrogen is made from natural gas or naphtha.In the hydrogen fuel concept, where much largeramounts of hydrogen would be required, water,considered inexhaustible, would be the primary rawmaterial source for hydrogen. Hydrogen is cur-rently being made from water by electrolysis inCanada, Norway, India and Egypt. This method ofmaking hydrogen is used either because of theavailability of cheap hydroelectric power or a lack ofnatural gas.

Keeping in mind at all times that hydrogen is not aprimary energy source, we investigate the promisingprimary energy sources for the production of hydro-gen. Figure 19 indicates the two main processroutes for making hydrogen; first, thermal energy isconverted to electricity via a vapor cycle and then tohydrogen by electrolysis, and second, thermalenergy is converted directly to hydrogen by a closed-cycle thermal decomposition process. Systemsshown by the paths in the figure are evaluated toobtain costs of hydrogen using certain of thesealternatives. In addition, environmental factors aretaken into account, even though it is difficult to

THE PRODUCTION OF HYDROGEN

assign dollar values for these factors.

The results we obtained from the analysis aresummarized briefly: Hydrogen will be produced bycoal gasification in the near term to 1985 andprobably to 2000. Concurrently and beyond, hydro-gen could be made using nuclear power-electrolysiswith presently available technology, but it is felt thatthe costs incurred using this method would not becompetitive with costs using other methods. Beyondthe intermediate term, we envision that hydrogen willbe produced from nuclear heat and closed-cyclethermal water decomposition. Solar power willreplace nuclear heat if the costs of obtaining solarheat are sufficiently reduced by emergent tech-nology. The above remarks also apply to schemessuch as wind power combined with electrolysis.

Hydrogen From Coal

In Figure 20, the identifiable and recoverable coalreserves are much greater than either petroleum ornatural gas reserves. In recognizing that coal is thelargest domestic reserve, President Nixon, in hisApril, 1973 energy message to the nation, advocatedgreater amounts of money for coal research. Bothcoal and oil shale, the reserves of which are alsolarge, have the associated environmental problemsof mining, mine safety and waste disposal. Presentconsumption of fossil fuels is also shown in Figure20. We presently supply 18 percent of our energyneeds with coal—primarily for electric generation.This percentage is estimated to increase to 70

SOLAR SOLAR RADIATION •

FOSSILFUELS

WIND

POTENTIAL ENERGY.OF WATER

OCEANIC THERMAL-GRADIENTS

ORGANIC WASTES —

PHOTOLYSIS CELL

SOLAR CELL

THERMAL COLLECTOR

WIND TURBINE

PHOTOSYNTHETIC PLANTS

COAL

•*- WATER TURBINE

-*- PUMPING SYSTEM

-*- COMBUSTOR

COMBUSTOR

GAS PROCESSOR

_^_ COAL GASIFIER (?)COMBUSTOR

GAS, OIL

GEOLOGICALENERGY GEOTHERMAL

BREEDER

FUSION

FISSION

COMBUSTOR

• STEAM WELL

• REACTOR

• REACTOR

• REACTOR

HttMO-CHEMICAlDECOMPOSITION

OF WATER

Figure 19. Hydrogen Production Systems

12

ORIGINAL PAGE ISOF POOR QUALITY

percent by 1985, as detailed in a recent publication(1973) of the Council on Environmental Quality.

NASA-S-73-2S74

IN SITU COAL GASIFICATION CONCEPT

HYDRO

FOSSIL ENERGYRESOURCES AND USE

RESOURCES CONSUMPTION

Figure 20. Fossil Energy Resources and Use

From coal, we could synthesize gaseous or liquidhydrocarbons, if a source of hydrogen is available.Steam and heat (possibly from combustion of partof the coal) could be used to make hydrogen asshown in Figure 21. This process is less efficientthan making methane from coal, as all the carbon incoal is rejected to the atmosphere as carbon dioxide.In addition, manufacture of hydrogen from coal hasnot been demonstrated fully on a commercial scale.However, the technology is similar to that of produc-ing methane from coal and the feasibility of the pro-cess seems to be assured. In order to lessen theenvironmental impact of large scale strip-mining ofcoal, in situ gasification of coal may be used toproduce hydrogen from a mixture of oxygen andsteam or water pumped into a previously ignitedcoal seam as seen schematically in Figure 22.

GAS PURIFICA'PLANT

-PIPEimEJSAS ^ OAS PRODUCTION WELLS

-OXYGEN PLANT

WATER PLANT

INJECTION WELLS

REACTION ZONE

Figure 22. In Situ Coal Gasification Concept

Hydrogen From Nuclear Energy

The next alternative employs nuclear energy by oneof the two processes mentioned earlier to producehydrogen. A schematic of the path, nuclear power-electrolysis is shown in Figure 23. Treated water iselectrolyzed by using low voltage direct currentpower to obtain hydrogen. This process has beenevaluated recently by the Synthetic Fuel Panel atOak Ridge National Laboratory and by the Institute ofGas Technology. Basically, the cost of electrolytichydrogen depends on the cost of electricity. Pro-ponents of this system derive a low cost for hydro-gen by the use of "off-peak" power from base loadplants because intermediate and peaking plantssupply the highs in electric power demand. In a largehydrogen economy, supplying 20 to 50 percent of thenation's energy requirements, it is difficult to foreseemuch "off-peak" power being available for electroly-tic hydrogen.

.A».»»M, CQAL GASIFICATION TOPRODUCE HYDROGEN

„«..,.,„„. v^ ELECTROLYSISCHEMICALS^

COAL

HYDROGEN

A/SPENT DOLOMITE

DOLOMITE

- PURIFICATIONCaO+CO2 — CoCO3

CaO+H2S -CaS+H2OB - SHIFT CONVERSION

CO+H2O —CO2+H2

A - GASIFICATIONCOAL—CH4+CC+H2O—CO+H2CO+HjO —COj+H2

C+2H2—CH4

Figure 21. Coal Gasification to Produce Hydrogen Figure 23. Nuclear Power - Electrolysis Schematic

13

Conventional electrolysers having conversion effi-ciencies of 60 to 70 percent are available today.Efficiency is the ratio of electric energy input tothe heating value of the hydrogen output. This typeof electrolyser suffers from high capital costs due tolow current densities, typically 100 to 200 ampsper square foot. Advanced concept electrolysershave been proposed and built by various companies(GE, Teledyne, etc.) based on NASA derived fuelcell technology. Electrolysers of this type arecapable of operation at higher efficiencies andcurrent densities. Despite these improvements, theprice of electricity is still the dominant factor inelectrolytic hydrogen costs.

The path (vertical line) from 1 to 5 represents waterelectrolysis with a large work (free energy) require-ment and a small heat requirement. (This is shownby the length of the path in the W portion as com-pared to the Q portion.) In contrast, a multi-stepthermochemical route is denoted by steps 1 through5 without any work other than that used to separatethe reaction products. This work can be minimizedby using easy phase separations (gas-solid). Themulti-step process is seen to operate at a muchlower temperature, typically 1000°K, as comparedto the one-step process at 2000°K. A typical set ofprocesses is seen in Table 1.

In a second type of process, water can be split byapplication of thermal energy or heat. One step andmulti-step processes for closed-cycle thermal de-composition of water have been proposed and tested.In the one step mode, the hydrogen produced fromsteam may be separated by means of a palladiummembrane. Under equilibrium conditions, tempera-tures in excess of 2000°K are required for reason-able conversion of water to hydrogen. At JohnsonSpace Center, NASA is presently researching thisprocess under non-equilibrium conditions at lowertemperatures.

TABLE 1. HALIDE PROCESSES

CALCIUM BROMIDE PROCESSDe Beni, Euratom, 1970

CaBrz + 2 HhO—- Ca(OH)2 + 2 HBr 730°CHg + 2 HBr^ HgBrz + H2 250HgBrz + Ca(OH>2— CaBr2 + HgO + H2O 200HgO—- Hg + Vi 02 600

STRONTIUM BROMIDE PROCESSDe Beni, Euratom, 1970

SrBr2 + H2O SrO + 2 HBr 800°C2 HBr + Hg HgBr2 + H2. 200SrO + HgBr2— SrBrz + Hg + Vi 02 500

Multi-Step Thermochemical Processes

More importantly, a number of multi-step processeshave been proposed to split water. The only productsof a series of these reactions are hydrogen and oxy-gen. A plot of enthalpy versus temperature (Figure24) shows the advantages of a multi-step process.

ntOCESS SCHEMEH2O—AA—H2+Vi02

ENTHALPY (Iccol/g-mol.)

0 ... 500 1000 1500 2000 2500TEMPERATURE (°K)

Figure 24.Enthalpy - Temperature Diagram for Water

Decomposition

The first process, labeled "Calcium Bromide", isthe Mark 1 process invented by Marchetti of Eura-tom in Italy. Note that the maximum temperature ofthis process is 730°C or approximately 1000°K.Another process investigated by this European groupis shown as the strontium bromide process. Atpresent, Marchetti and his co-workers are investi-gating a Mark 9 process based on iron oxide andhydrogen chloride reactions. A combination ofthermal decomposition and electrolytic processesmay be used to advantage in lowering the work(free energy) requirements. It takes less electricalenergy or work to decompose hydrogen chloridethan water. Examples of these processes are seenin Table 2.

TABLE 2. CHEMICAL-ELECTROLYTIC PROCESSES

HYDROGEN CHLORIDE ELECTROLYTIC PROCESSHallett, Air Products, 1965

H20 + CU 2HCI + '/2O22 HCI H2 + Cl2 (Electrolysis)

MERCURY CHLORIDE ELECTROLYTIC PROCESS

700°C300

HzO + Clz 2 HCI + '/2 O22 Hg + 2 HCI 2 HgCI + H2

I —2 Hg + CI2

700°C300

(Electrolysis) 500

14

In comparing these processes, we note, in addi-tion to the efficiency (defined as the ratio of theheating value of the hydrogen output to the thermalenergy input), the following properties: the maximumtemperature of the process heat requirement whichgoverns the type of primary energy input, and thepercentage of the heat required at that particulartemperature. The latter factor is very importantif solar energy is used, because the cost of solarheat increases with the collection temperature.Sixty thermochemical processes were investigatedand the number grows as new investigators enterthe field.

Solar energy may well be the ultimate solution to theenergy problem. Two difficulties exist with solarenergy as a primary source of energy; it has a lowdensity and is intermittent (Figure 25). At noon in

NAIA-S-73.2520

SOLAR ENERGY DENSITY AT 2 LOCATIONS,

FOR 3 DIFFERENT SEASONS

c

° 800

tn

5 600

1 400

52 200Of<

O 0

ARIZONA DESERT - EQUINOX

WASHINGTON DC - SUMMER

WASHINGTON DC - WINTER

6 8AM

10 12 2

TIME OF DAf

4 6PM

Figure 25. Solar Energy Density at Two Locationsfor Three Different Seasons

the Arizona desert, the solar flux amounts toapproximately 1 kilowatt per square meter. It hasbeen estimated that this country's energy require-ments could be met by a 75 mile by 75 mile area inArizona covered by solar collectors. The energysupply is apparently free, but the cost of collectionis high. Three schemes were evaluated for obtaininghydrogen from solar energy. The first method, usingsilicon solar cells at $7000 per square meter, wasmuch too expensive. The second method used aparabolic trough collector to produce steam whichcould be converted to electricity by a vapor cycle,followed by electrolysis of water to produce hydro-gen. This method also was considered too expensive.The third method used solar energy in conjunctionwith the water thermal decomposition step discussedin the previous paragraph. The capital cost for thismethod was estimated at $500 to $600 per kilowattof installed capacity, which is comparable to presentday nuclear plants. The primary output of solarenergy conversion is electricity and the problem ofenergy storage for night and cloudy hours of the daywould have to be solved to effectively use solarenergy. The relative ease of storage of hydrogenwould add much greater flexibility to a solar system,if hydrogen can be produced efficiently and eco-nomically from this primary source of energy.

Other process paths that are not presently feasible,but remain as candidates for further study, includesolar-photolysis, hydrogen production from wastesvia bioconversion methods, and from oceanic ther-mal gradients.

15

COST OF PRODUCING HYDROGEN

Cost projections form part of a systems analysis.The five most promising system alternatives forevaluation are listed below: (Not in order of impor-tance or preference):

nuclear power - electrolysiscoal gasificationnuclear heat - thermal decompositionsolar heat - thermal decompositionwind - electrolysis

Figure 26 summarizes the alternatives consideredin the study. An optimistic and a pessimistic pro-jection for each process has been given for thepresent, or for when the future technology is pro-jected to be developed.

The cost of electric power is more likely to be from7 to 12 mills per kwh. With costs in this range,hydrogen by electrolysis would be in the $3.00 to$5.00 per million Btu range. Lines 1 and 1A ofFigure 26 indicate these trends. We have not in-cluded credit for by-product oxygen from the elec-trolysis step. Sale of this oxygen could possiblylower costs by 30 percent. This option is uncertainbecause markets for the oxygen must be found.

Coal Gasification

The lowest costs are in the range of $1.00 to $1.50per million Btu for hydrogen produced by the coal

NASA-S-73-2618

HYDROGENPRODUCTION

COST $/106BTU

10.0

1.0

-1A 4A

0.11970

I

1 NUCLEAR-ELECTROLYSIS, OPTIMISTIC

1A NUCLEAR-ELECTROLYSIS, PESSIMISTIC

2 NUCLEAR HEAT-THERMAL DECOMPOSITION,OPTIMISTIC

2A NUCLEAR HEAT-THERMAL DECOMPOSITION,PESSIMISTIC

3 SOLAR HEAT-THERMAL DECOMPOSITION,OPTIMISTIC

3A SOLAR HEAT-THERMAL DECOMPOSITION,PESSIMISTIC

4 WIND - ELECTROLYSIS, OPTIMISTIC

4A WIND - ELECTROLYSIS, PESSIMISTIC

5 COAL GASIFICATION, OPTIMISTIC

5A COAL GASIFICATION, PESSIMISTIC

6 IMPORT LIQUID NATURAL GAS

7 SYNTHETIC NATURAL GAS

8 NATURAL GAS FROM ALASKA1980 1990 2000 2010 2020

YEAR

Figure 26. Hydrogen Production Cost for Various Alternatives

Nuclear Power - Electrolysis

The cost of hydrogen via this route depends on thecost of electricity. Off-peak forecasts of 2.5 mills perkilowatt-hour (kwh) would yield a cost of hydrogenin the range $1.00 to $1.50 per million Btu. Presentlythere is little off-peak power in this cost range andnone envisioned for supplying hydrogen economy.

gasification process. See lines 5 and 5A of Figure26. This process would compete with those formaking methane from coal since costs are in thesame range. Moreover, the use of methane pro-duced from coal would not require a change inburners, pipeline systems and conventional practice.Because of these factors, the production of methanefrom coal will probably precede hydrogen from coal.

16

Nuclear Heat - Thermal Decomposition

If the technology should be developed by the year1985 and"; efficiencies' in the 50 percent rangerealized for this process, estimates of costs are$1.00 to $1.50 per million Btu for hydrogen (lines 2and 2A) produced from nuclear heat, followed bythermal decomposition. This alternative, besidescompeting favorably with coal gasification processes,would have less environmental impact. This processshows great promise because of the predicted effi-ciencies and the lower cost for hydrogen comparedto that obtained from the nuclear power - electroly-sis processes. It is this fact that lends impetus tothe growing amount of research being carried out inthis area today, both in the United States andabroad, primarily in Italy and Germany, where a hightemperature pebble-bed nuclear reactor operatesroutinely at 1100°K in this service.

Solar Heat - Thermal Decomposition andWind - Electrolysis

Both of these options are considered in the inter-mediate and long term period. Due to the diffuseintermittent nature of the sources of energy and thelarge capital costs of collection, a cost of $2.00 to$3.00 per million Btu for the production of hydrogenis estimated. This range is similar to that for thealternative nuclear power - electrolysis in the inter-mediate time period. If hydrogen should be needed

before this, and could not be obtained from coal,nuclear power - electrolysis could satisfy thatdemand, as the technology is currently available.One would, of course, have to pay a high cost dif-ferential.

From an environmental point of view, coal isprobably the worst offender in terms of "socialcosts." This is due to strip mining, mine safety,and sulphur and ash disposal problems. Nuclearplants are probably the next worse offender. Ques-tions have been raised concerning siting, safety,and waste disposal of the spent fuel. The ultimateform of energy may be derived from solar sources,including wind power.

In summary, it is feasible to produce hydrogen byseveral schemes. Some of these schemes can beimplemented immediately; nuclear power - electroly-sis at costs in the $3.00 to $4.00 per million Bturange, and coal gasification at approximately $1.50per million Btu. This cost could be maintained inthe immediate term to 2000 and in the long term to2020 by using a primary heat source coupled witha water thermal decomposition process, if the latterprocess can be developed commercially. Solarenergy may prove competitive at that time. We seeno one process as completely dominating the totalmarket as a source of energy for hydrogen produc-tion systems. The choice will depend on economic,environmental and other factors.

17

TRANSMISSION AND STORAGE

OF GASEOUS HYDROGEN

All economical methods will produce hydrogen in agaseous form. The use of hydrogen, gas or liquid,as a fuel will necessitate the development of large-scale transmission and storage systems. In orderto move this energy carrier from producer to userit will be necessary to utilize transmission andstorage methods that have been found to be eco-nomical and practical by producing industries in theUnited States. A hydrogen gas pipeline system simi-lar to the existing natural gas pipeline systemappears to be the most practical solution. Thepipeline system must be capable of deliveringhydrogen gas directly from the generating plant tothe user. It will be necessary to provide some stor-age capacity to meet daily and seasonal peakshaving requirements. Daily needs may be econom-ically satisfied by line pack storage. Seasonal peakshaving requirements may be satisfied most eco-nomically by large scale underground storage indepleted natural gas fields, aquifers, or other suit-able natural formations. More costly peak shavingstorage may also be accomplished by high pressuretanks, liquid hydrogen, and gas storage in minedcaverns.

One important question arises from all studiesconcerned with the transmission of hydrogen. Canthe present natural gas transmission system beused? The answer is uncertain because the trans-mission of hydrogen at high pressure may causeembrittlement of pipe material. It will be necessaryto examine the feasibility of converting portions ofthe existing natural gas pipeline to hydrogen trans-port. Some research will be needed to establishspecific design criteria for various portions of thissystem. It appears that conversion of present pipe-lines can be accomplished with a moderate amountof problems, but there is a possibility that anentirely new transmission and storage network maybe necessary. A new hydrogen pipeline system canbe implemented using present day technology.Existing natural gas transmission lines could be usedto transmit an equal amount of energy in the form ofhydrogen gas, but such a system would requireapproximately four times the present compressorcapacity and over five times the compressor horse-power. The projected cost of hydrogen gas trans-mission is, therefore, higher than natural gastransmission, but will be significantly less thanoverhead electrical transmission (Figure 21). It willbe economical to transmit large quantities of energythrough a hydrogen gas pipeline system. The cost ofhydrogen generation will affect the overall economyof a hydrogen energy system much more than thecost of transmission and storage of hydrogen gas.

Potential Hydrogen Embrittlement

The metallurgical problem that is of most concernif we are to use existing pipelines for hydrogen isknown as hydrogen environment embrittlement,which was first recognized in the mid-1960's. Whena metal susceptible to hydrogen environment em-brittlement is plastically deformed in the presence ofhydrogen gas, cracking can occur at the surface.The problem is generally observed in relatively purehydrogen at high pressures and moderate tempera-tures. Actual deformation of the metal is required inthe presence of hydrogen for embrittlement to occur.Combinations of residual stress and stress concen-trations that occur from fabrication of the pipeline orexternal stresses such as caused by pipeline move-ment can add to the working stress value and ac-tually cause yielding at localized points. In the pres-ence of natural gas this localized yielding has notbeen serious, but in the presence of hydrogen thelocalized yielding may result in cracking. As faras could be determined, no research on pipelinesteels with regard to hydrogen environment embrit-tlement has been reported. It has been determinedthat certain impurities can inhibit or eliminate thesusceptibility of a metal to hydrogen environmentembrittlement. Most of the proposed chemical andthermochemical processes will not yield gaseoushydrogen of ultra high purity.

It appears that most operating conditions in a hydro-gen system would favor the use of existing pipelines.However, until safety is assured, as a result of re-search in pipeline materials under actual oper-ating conditions, any conversion project must beapproached with caution.

Liquid Hydrogen

Liquid hydrogen may also be considered as anenergy carrier. Transmission and storage charac-teristics of liquid hydrogen are unique and speciallytrained personnel are needed to handle hydrogenin this form. The liquefication of hydrogen is costly,although the required technology has been devel-oped for some time. The expense arises from twofacts: First, the process requires a great deal ofenergy, and second, the process involves verycomplicated, and hence expensive, equipment.In addition, if storage of the liquid hydrogen isrequired, the storage tank cost must be added to thecost of liquefaction.

As a result of these costs it is apparent that hydro-gen will be transported and stored as a liquid only if

18

there is no alternative. One such area of use maybe the storage of energy for peak-shaving in a largepower system where suitable gas storage facilitiesare not available. If the hydrogen must be liquefiedfor some purpose, such as peak-shaving, then thecryogenic properties of the liquid may be useful forother purposes. One potential use is the cooling ofunderground electrical cables to minimize the re-sistive power losses. Such cables could not competewith present overhead cables, but they may havesufficient environmental and aesthetic advantagesto be justified in the future.

hydrogen storage, it appears that hydrides as fuelstorers will be limited to small scale specific usesrather than to large scale general uses. The reasonsfor this are the very poor mass energy densities andthe probable high costs of metals. In addition, large-scale storage would involve excessive amounts ofthe world production of many of the metals used tomake hydrides. The economics of hydride systemsare uncertain and must be analyzed carefully to geta fair comparison with gaseous and liquid hydrogenstorage systems. Typical metal hydrides are listedin Table 3.

Metal Hydrides

Hydrides have some useful and advantageousproperties when compared with gaseous and liquidhydrogen, particularly volume energy density. Eventhough the gas is stored at densities greater thanliquid hydrogen, in hydride usage there are noassociated liquefaction and cryogenic storage prob-lems. However, even with the advantage of process-ing economics and handling safety over liquid

TABLE 3. TYPICAL METAL HYDRIDES

MaterialL1AIH4BaBHiLaNisHsB2H6

MgHzL1BH4

Weight PercentHydrogen

10.510.61.4

21.07.6

18.3

19

NONTECHNICAL ASPECTS OF A HYDROGEN ECONOMY

We include in our study of the hydrogen fuel systemsome preliminary estimates of how that systemwould impact upon, and be impacted by, society.There are many ways in which society will change,during the next decades; and there are many waysin which hydrogen may, or may not, be incorporatedinto our energy system.

It is a hallmark of the technological society that wedefine problems and then set about solving them,rather than asking if the condition is really a problemor only defined as such, and whether we might bebetter off living with it. To a technological society,the fact that we seem to have developed moreenergy demand than we can supply is a problem, andthe obvious solution is to build more power plants.Further, due to social and intellectual inertia, thetype of plant we decide to build is probably the typeto which we are already accustomed, rather thansomething new and unusual. We may be forced to dojust that.

Americans believe in progress; that progress meansgrowth; and that growth is keyed to energy use.The American energy system feeds a need forabundant, ever-increasing quantities of low-costenergy. It was based on assumptions that domesticsources were virtually limitless. But the presentenergy shortage upsets beliefs and belies assump-tions. The fundamental question now is, can wecontinue our present exponential rate of energyconsumption? Clearly, the answer is no. In a finiteworld there are limits to growth. This does not implythat, as natural energy resources dwindle, we shallall freeze to death in the dark; but, it does mean thatAmericans must make two new assumptions:

New energy sources must be found,Energy prices will be higher.

We believe that hydrogen can play a significant rolein the future American energy system.

The current energy shortage is not simply a tech-nological problem subject to technological solutions.It is also a safety, legal, economic, environmental,political and social problem. We have sought toanalyze a potential switch to hydrogen fuel in thoseterms. Our major conclusions are:

Environmentally, hydrogen is a desirable energycarrier. It is clean burning, transmissible andstorable underground. It is ecologically com-patible because of its relatively short recyclingtime. Some present and' proposed methods ofproduction, however, may be environmentallyobjectionable.

Hydrogen fuel would be readily acceptable inthe American energy system. A changeoverwould have minimal impact on social, legal,political and economic institutions.

Hydrogen fuel's only potential drawback maybe public fears that it is more dangerous thantoday's fuel (The Hindenburg Syndrome/-Hydrogen Bomb). Public education and safetyprograms can change the image and gainacceptance for a marginally increased, accept-able risk.

Is Hydrogen Safe?

In the area of safety, the states have had the majorresponsibility. Within the last few years, however, avery definite trend has developed; its major pointsare:

Increased federal responsibility in both safetycodes and workmen's compensation,

•'Increased federal regulation of safety with the/ {preemption of state authority to set higher or

^different standards.

Should hydrogen enter the energy system, we canexpect comprehensive federal regulation of hydro-gen and a comprehensive safety code. Also, shoulda conflict result between federal and state authorityover safety and health conditions connected withthe use of hydrogen, we can expect that the courts,even in the absence of legislative expression, willfind that Congress has preempted state authority.

Given the general concensus that petroleum fuelsare being rapidly depleted, that their prices will rise,and given the powerful and still growing concern forenvironmental protection, American society may befaced with a trade-off in which a risk of someincreased danger will be exchanged for havingenergy in the quantities desired. This is not to saythat hydrogen should not and cannot be developeduntil the environmental risk is low. It is, however,to argue that we cannot dismiss hydrogen simplybecause it is marginally less safe now than are theother fuels to which we have become accustomed.

The largest single obstacle to a hydrogen economy isprobably public fears about safety. It is widelybelieved that hydrogen is a dangerous substance.This belief is correct. But all forms of energy aredangerous, if improperly used. There are few Amer-icans indeed who have not experienced energyhazards and accidents. It is even possible that initial

20

public concern may lead to development of a hydro-gen energy system hedged with safeguards whichrender it safer than is our present system. Hydrogenis dangerous in different ways than is gasoline,natural gas or electricity, but is not necessarily anabsolute danger. We believe that society can learnto protect itself from most errors and live with theremaining risk, as we already do with existing energysystems.

Much of the fear of hydrogen is based on unfamiliaritycoupled with the image of a famous disaster. Giventimely enactment of the necessary safety codes andthe application of what is largely state-of-the-arttechnology to safety devices, the remaining require-ment will be public education. There is a conventionalpublic education and public relations method whichshould be able to counter unfounded public fearsabout hydrogen. It is the truth. The H-Bomb imageis so wildly at variance with fact that it can andshould be easily corrected for all but the very few.The Hindenburg Syndrome is rather more difficult.The dangers exemplified by that incident are real andmust be dealt with. It will be necessary to show thathydrogen dangers can be met and that safetystandards can obtain acceptable risk levels.

Legal Aspects Of A Hydrogen Economy

The American energy system is heavily regulatedby the federal government. But, Congress has reliedupon the states in many instances to supplementthe federal government's regulatory power. Evenwhen federal authority has been exercised, the usualpattern is a dual system of federal and state authority.State authority is perhaps most pervasive in the coalmining industry, where comprehensive safety codes,siting requirements and pollution standards abound.State residual authority in the petroleum industryis likewise quite comprehensive. A well known illus-tration is the powerful Texas Railroad Commission.Some generalizations and forecasts can be madeabout governmental regulations in the near futurefrom a comparison of two recent Supreme Courtcases.

In Offer Tail Power Company v. United States,the Supreme Court was presented with the questionof a power company's refusal to deal with certaincity corporations wanting to provide their ownservice to residents by purchasing, at wholesaleprices, electrical energy produced by the company.Although the case concerned the anti-competitiveeffect of the power company's refusal to deal, theCourt noted that the Federal Power Act, thoughcomprehensive, still allowed dual governance ofeconomic decisions between the public sector(federal government) and the private sector (private

owners). Thus, as private ownership is maintained,commercial relationships are governed, in the firstinstance, by the private business judgment of thecompany. This results despite the fact that thecompany is a highly regulated natural monopoly.In other words, there is still a zone of freedomallowed by a regulatory act where private decisionmaking is generally unregulated.

Similarly, there are many cases where federal regu-lation is not exclusive, but rather shared with thestates. Such an issue was recently involved inFPC v. Louisiana Power & Light Company. That casepresented the fundamental question of whether ornot the FPC was empowered by the Federal PowerAct to take certain regulatory action over the Com-pany. The Company argued that the FPC had nojurisdiction. The Supreme Court, construing theNatural Gas Act of 1938, noted that the FPC hadbeen granted broad powers "to protect consumersagainst exploitation at the hands of natural gasmonopolies." To that end Congress "meant to createa comprehensive and effective regulatory scheme"of dual state and federal authority. The Court alsonoted that although federal jurisdiction was not tobe exclusive, FPC regulation was to be broadlycomplementary to that reserved to the states, sothat there would be no "gaps" for private intereststo subvert the public welfare. Thus the questionbecame: Which jurisdiction should fill the gap?To this question the Court answered that

When a dispute arises over whether a giventransaction is within the scope of Federal orState regulatory authority, we are not inclined toapproach the problem negatively, thus raisingthe possibility that a no-man's land will becreated. That is to say in a borderline casewhere Congressional authority is not explicit,we must ask whether State authority can prac-tically regulate the given area and if we find itcannot, then we are impelled to decide thatFederal authority governs.

Noting that there is inevitably a conflict betweenproducing states and consuming states (whichcould create contradictory actions, regulations,and rules that could not possibly be equitablyresolved by the courts), the Court felt that a uniformfederal regulation was desirable. The Court,therefore, concluded that the matter in questionwas indeed within the jurisdiction of the FPC. Theimportant fact from the case is that competitionfor energy among the states gives rise to a diversityof state resolutions, thus impelling the Court to findthat the area is federally regulated. This insuresregulation in the national interest, but diminishesthe regulatory power of the states.

For a number of years, spokesmen for the energy

21

industry have noted the need for a national energypolicy and coordination among the various federaland state regulatory agencies. Prompt action seemscertain. As recently as April, 1973, President Nixonproposed the establishment of a cabinet-levelagency entitled the Department of Energy andNatural Resources, which would be responsible forthe balanced utilization and conservation of our na-tion's energy and natural resources. The proposedDepartment would consolidate many of the regula-tory functions scattered throughout the federalstructure.

Thus, it may be that the federal and state regula-tory structures will be consolidated into a singlefederal cabinet-level department. Surely, as the de-mand for energy increases and the supplies de-crease, this agency will be given more and morefunctions of research, development, funding and re-gulation of the entire energy picture. It may alsobe forecast that as the problems of energy use andsupply become more critical, more and more func-tions will be taken away from the states by the feder-al government. This is indicated by the SupremeCourt's decision in FPC v. Louisiana Power & LightCompany where we found the U. S. Supreme Courtsaying that a federal regulatory agency, in effect,abhors an energy system vacuum.

Since several of the suggested methods for theproduction of hydrogen would use large quantitiesof water and produce substantial quantities of re-ject heat, it has been suggested that the plantsbe located offshore. Proposed offshore locationsrun all the way from the shoreline, to the territorialsea, to the contiguous zone, to the continental shelfsea area, to the high seas. Each one of these sitinglocations itself, along with the production processby-products (primarily salts and reject heat), andthe use of large quantities of water, all raise seriousinternational law questions.

The threshold question is, who owns the seas? Thetraditional answer to this question has been, no one.Under the basic principle of the freedom of the seas,the water itself, the marine life, and the minerals(in and under) belong to no one; or, in other words,they were treated as res nullius. Since the seas andits resources belong to no one, it follows that anyonecould use them in any manner for any purpose.There are, however, growing signs of an inclinationto treat the oceans and its resources as being shared.This change indicates that the seas are limited toreasonable uses. Overboard reject heat and produc-tion by-products may constitute an unreasonableuse.

There are still many open questions in internationallaw and there are many developing ideas. The ul-

timate shape of international law must await theresults of the 1974 world conference on the Law ofthe Seas, but one final note must be made. Thatconference may write into the new law of the seasa wholly new concept. That emerging concept maybe labeled Shared Development. Significantly, theconference was called to write a treaty for the de-velopment and sharing of the ocean's resources.Similarily, the basic premise of the report to theUnited Nation's 1972 Conference on the HumanEnvironment was that a certain level of developmentnot yet reached in the developing countries is aprerequisite for a decent environment and all nationsmust help the have-nots. Thus, if a hydrogen pro-duction facility were to be sited on the high seas,it may well run into severe objection on environ-mental grounds, and/or strong demands from thedeveloping countries of the world for a share ofthe fuel produced.

Environmental, Economical and SocialFactors of a Hydrogen Economy

Hydrogen is environmentally an almost ideal fuel.It is significantly cleaner than, hydrocarbon fuels,and its only combustion by-products should be easilycontrolled. Hydrogen transmission by undergroundpipeline offers aesthetic advantages over conven-tional electrical transmission. Hydrogen's environ-mental impact is likely to be highly positive, allowingcleaner cities and factories. The adverse impact, ifany, will be connected chiefly with the method bywhich hydrogen is originally produced.

United States material wealth and national powerhave rested upon a relative abundance of naturalresources, an industrious and capable population,an abundance of energy and an occasional bit ofluck. Data indicate a close relationship betweenhigh energy consumption rates and high Gross Na-tional Product per capita for a large sample of na-tions. American society is an affluent (even effluent)society in which the availability of massive quanti-ties of energy at low prices has been a major sup-porting element. In the current energy shortage weface important questions: Can enough energy atlow enough prices be assured that we can maintainour way of life indefinitely into the future? Failingthat, can other ways of life be found which are lessenergy-intensive, but still satisfying? Can otherfactors substitute for high-level energy consumption(better information, different social values empha-sizing areas of low energy use, etc.)? Do we havethe intellectual tools to really understand and analyzesuch questions?

We know little about the role of energy as a socialforce, but we do know that the role is important. It

22

is probably much more important than we botheredto notice during times when energy and reserveswere abundant. We know ve'ry little about how tocalculate social costs.

Industrialized, high-technology society rests upon abase of energy, but each different energy base andeach different application method exerts peculiareffects upon the larger social context. A large scalehydrogen economy will require capital investmentexpenditures beyond the capacity of all but thelargest institutions and may result in new patternsof public-private ownership. A switch to a hydrogenenergy system will also alter existing economicflows, both domestic and international. Legal pro-visions, political power and pressures, and environ-mental constraints must be redesigned and recal-culated. But similar changes have been experiencedbefore, as the nation went from wood to coal, fromcoal to petroleum, and—perhaps more apropos tothe hydrogen economy—as natural gas use spreadswiftly during the 1950's.

We are now beginning another change in ourenergy base, but this time there are several ques-tions. It is neither clear what the new energy basewill be nor is it clear what medium will be chosen tocarry and distribute the energy. We may be movingtoward a mixed base power system where nuclear(fission, breeder and even fusion) will coexist withsolar, geothermal, ocean temperature gradients,and perhaps others even more exotic. We may useelectricity to distribute the base power, or we mayuse hydrogen, or both.

There are other complications to this energy change.For the first time, environmental preservation hasbecome a general force in society with legal, politicaland economic muscle unknown in prior energy/-society relationships. We are even beginning to facethe certainty that infinite growth in all things is nota real possibility, which leads inexorably to a pre-viously unthinkable question: If we must "stop"growth, when and on what terms shall we stop?

We can state that, to the degree that a new fuel iscompatible with present uses of the old fuel, and tothe degree that replacement can be carried out atlow cost in dollar terms and life style changes, itwill be quite socially desirable. Hydrogen offerspotential improvements in the environment, andprotection against external influence. It is now timeto develop careful studies which can clarify and per-haps even answer some of the questions raised inthis report.

Political Aspects Of A Hydrogen Economy

American use of energy has meshed with severalstrong values in the American social, political, and

economic system to produce a peculiar set of inputsand outputs. The society has made several demandsrelated to energy provision and utilization:

that progress must exist in an observable fash-ion, generally in the form of an ever-risingstandard of living measured chiefly in materialgoods, that the premise of a consumer-controlled, market economy based upon a sys-tem of private property and private competitiveenterprise must be maintained as a value andas a symbol that the public image of the UnitedStates as a great nation be preserved. All ofthese requirements produce an implicit energypolicy,

the supply of energy must be adequate at alltimes, which means that it must constantlygrow larger,

the price of energy must be kept at a levelwhich does not impede its use to support prog-ress,

energy production should be carried outprimarily by private enterprise, although govern-ment regulation is allowed as a (regrettable)necessity due to the interstate character ofenergy supply, natural monopolies, and otherfactors.

There is a very serious, potentially revolutionarypolitical content in the energy shortage. The entireAmerican economy, many social values and majorpolitical patterns depend upon massive and growingquantities of (relatively) cheap energy. Suggestionsthat we may be forced to reduce our energy con-sumption are usually considered crackpot solutions.Despite pleas to conserve energy by driving moreslowly, change the thermostat setting or make someother saving in energy consumption, the emphasisis nearly always on ways in which supplies can beincreased to meet the demand. The present shortageis viewed as real, but temporary. Suggestions forreal and permanent reductions in energy consump-tion are greeted with warnings of stagnation, unem-ployment, reduced living standards- and a loss ofinternational status.

The United States now depends very heavily uponpetroleum energy. Since we are no longer self-sufficient in petroleum energy, and since we alreadyuse far more than a proportional share of the world'sscarce hydrocarbon resources, we must move awayfrom that potentially precarious base as rapidly aspossible. It would indeed be sobering to find our-selves faced with a choice of sudden and drasticcurtailment in energy consumption and consequenteconomic dislocation, or the possibility that a grow-ing petroleum shortage may lead to American and

23

European military seizure of Middle Eastern oil fields.Clearly, there is potentially enormous political con-flict involved in energy matters, and of a differenttype than the fairly well understood and endemicconflict between public and private power or theperennial maneuvering over the oil depletion allow-ance. Those have been marginal frictions over howand on what terms energy would be provided, com-pared to the now wide question of whether energycan be or should be provided.

Hydrogen is no solution to the energy shortagedespite the occasional hyperbole. As this reportmakes clear, hydrogen is not a source of powerbut a means by which energy may be transportedand stored. If the primary power problem can besolved, hydrogen does offer several advantagesover our current extreme dependence upon hydro-carbon fuels. In this sense it can contribute to aneasing of the shortage and become a part of ournormal energy system.

24

IMPLEMENTATION OF A HYDROGEN ECONOMY

Hydrogen is currently used in many industrial chemi-cal processes, and we believe that hydrogen can beintroduced into industrial process heat use as soonas it can be made available on a competitive costbasis. Electric power generation, using hydrogenas a peak-shaving fuel and as an energy storagesystem, is now in the development stage and showsconsiderable promise. Because of the very largevolume of hydrogen required and the problems ofconversion of existing gas line systems and gasequipment to burn hydrogen, the residential andcommercial use of hydrogen will occur later. Exceptfor the possibility of use in airplanes, the use ofhydrogen as a fuel for transportation probably willoccur last.

From these observations we have concluded thatany shift to a hydrogen economy must be a sequen-tial one. Although the chemical industry uses largetonnages of hydrogen, there is no established mar-ket for hydrogen as a fuel, except in the space pro-gram. We believe that direct experience in producing,pipeline transporting and using hydrogen as anenergy carrier is needed to demonstrate its feasi-bility for use in the nation's energy system.

Maximum participation by industry is desired toachieve the transition. In order to encourage partic-ipation, we propose that a guaranteed market beestablished for a number of years by a demonstrationproject. One possibility would be to select a powerplant which would be willing to shift to hydrogen,because of its location in an area with serious pol-lution problems. The supply of hydrogen fuel wouldbe solicited by bids from industry at a premiumprice for a specified number of years. The bidderswould be required to supply the hydrogen from afuel conserving process and to transport it by pipe-line for some specified minimum distance. The bid-der would be permitted to recover his developmentand design costs, capital costs and operatingcosts, spread over the life of the contract. A govern-ment subsidy or private foundation grant would beneeded to pay the difference between the cost ofhydrogen and the cost of conventional fuel. Thebidder would be encouraged to develop other mar-kets which also could be supplied by the hydrogenplant or an expansion of it.

Potential locations for a demonstration plant (aHyplex) would depend on the type of process to beused. If hydrogen is to be produced from coal, the

project could be sited in the general areas of Joliet,Illinois; Pittsburgh, Pennsylvania; St. Louis, Missouri,or any of several other locations. In each case thelocation is within pipeline distance of coal fields inwhich a gasification plant could be built. Suitableunderground formations are available for largevolume storage and several power plants whichcould convert to hydrogen are operating in theseareas. A potential hydrogen burning peak load unitis now being tested by Rocketdyne and Common-wealth Edison at Joliet. Steel mills, chemical plantsand other industrial fuel users are within pipelinedistance in each area.

If nuclear energy is to be used to generate the hydro-gen, similar combinations of power plants and indus-tries can be identified, where the nuclear plant couldbe located offshore or in the desert and the hydro-gen pipelined to the point of use. An example wouldbe Los Angeles.

Concurrent with or subsequent to the Hyplex demon-stration project, a larger demonstration project willbe needed as part of the sequential development ofa hydrogen economy. In order to include the resi-dential and commercial markets, an entire city(Hycity) would need to be operated on hydrogenfuel. An interesting possibility would be to designthe area for the next nuclear fuel processing planton the basis of hydrogen fuel. This facility will beneeded by 1985 and will require a 2000 megawattnuclear power plant to operate the processingplant. In addition, a 1000 megawatt plant will berequired as a stand-by plant to prevent the possi-bility of a catastrophic power failure to the process-ing plant. With proper storage facilities, the stand-by power plant could be used to produce hydrogenfor the city of 10,000 which would be associatedwith the plant.

As a final step, before full introduction of hydrogenfuel into the economy, an island might be convertedto the use of hydrogen fuel. In this case, thetransportation area could be added to the previouslyestablished markets. On an island such as Hawaii,all of the energy must be imported, thus any costdifferential would not be as great as for areas wherecheaper fuel is available. Final integration of hydro-gen into the energy system of the United Stateswould be the result of economic and environmentaladvantages of hydrogen as an energy carrier.

25