+ All Categories
Home > Documents > Making Hydrogen a Competitive Alternative to Fossil Fuels Through Anaerobic Digestion of Waste

Making Hydrogen a Competitive Alternative to Fossil Fuels Through Anaerobic Digestion of Waste

Date post: 05-Jul-2018
Category:
Upload: neil-scheibelhut
View: 225 times
Download: 1 times
Share this document with a friend

of 21

Transcript
  • 8/16/2019 Making Hydrogen a Competitive Alternative to Fossil Fuels Through Anaerobic Digestion of Waste

    1/21

    Making Hydrogen a Competitive Alternative to Fossil Fuels

    through Anaerobic Digestion of Waste

    By Neil Scheibelhut

  • 8/16/2019 Making Hydrogen a Competitive Alternative to Fossil Fuels Through Anaerobic Digestion of Waste

    2/21

    Table of Contents

    1. Introduction

    1.1 Signifcance

    1.2 Motivation

    1.3 Current Technologies

    1.4 b!ective

    2. Current Technologies

    2.1 Natural "as #e$or%ing

    2.2 Bio%ass "asifcation

    2.3 Coal "asifcation

    2.4 &lectrolysis

    2.' Microbial Bio%ass Conversion

    3. (ro)osed Bioreactor

    3.1 *)+o, -naerobic Sludge Blan et #eactor

    3.2 /ood 0aste as /eedstoc

    3.3 (retreat%ent o$ Munici)al Sludge

    3.3.1 eat Shoc Treat%ent

    3.3.2 -cid -l ali Treat%ent

    3.3.3 -eration

    3.3.4 *ltraviolet Irradiation

    3.4 I%)ortance o$ "enetic Se uencing

    4. /uture #esearch

    2

  • 8/16/2019 Making Hydrogen a Competitive Alternative to Fossil Fuels Through Anaerobic Digestion of Waste

    3/21

    '. Conclusion

    1 !ntroduction

    1.1 Signifcance

    -ccording to the Intergovern%ental (anel on Cli%ate Change greenhouse

    gases $ro% hu%an activities are the %ost signifcant driver o$ observed

    cli%ate change since the %id526 th century. Carbon dio7ide $ro% burning

    $ossil $uel $or energy and heat is the leading greenhouse gas e%ission

    8/igure 19. ver :'; o$ the ,orld. nly China

    82?;9 )roduces %ore o$ the ,orld.

    0ith no %itigation by the year 2166 the &arth. International concerns over global ,ar%ing

    are at an all ti%e high there$ore the need $or alternatives to $ossil $uels as

    energy sources has never been greater.

    Figure 1 Figure "

    Figure #

    3

  • 8/16/2019 Making Hydrogen a Competitive Alternative to Fossil Fuels Through Anaerobic Digestion of Waste

    4/21

    1.2 Motivation

    ydrogen is considered a )ro%ising $uel source as it )roduces only ,ater

    u)on co%bustion and is getting increasing attention as a clean energy

    alternative to $ossil $uels. Co%)ared to conventional $ossil $uels hydrogen

    has the )otential to )roduce t,o and a hal$ ti%es %ore energy than natural

    gas or gasoline ='>. In 266' the *.S. &nergy (olicy -ct ,as )assed and

    directed the energy secretary to conduct a research and develo)%ent

    )rogra% in consultation ,ith other $ederal agencies and the )rivate sector

    on technologies related to the )roduction )urifcation distribution

    storage and use o$ hydrogen energy $uel cells and related in$rastructureD

    =A>.

    ydrogen $uel cell technology has been around since the N-S- "e%ini

    days and they continue to use hydrogen as an energy source to this day. It

    is )ollution $ree ,ith only ,ater )roduced as a by)roduct and scalable.

    Because a single $uel cell only )roduces about one volt o$ )o,er they are

    co%bined in series to $or% a stac ,hen %ore )o,er is needed =:>. So $uel

    cells can be custo%iEed $or any a))lication. -dditionally hydrogen $uel

    cells are very eFicient co%)ared ,ith $ossil $uel energy generators. -

    gasoline co%bustion engine is only about 26; eFicient ,ith %ost o$ the

    energy lost as heat. Co%bustion based )o,er )lants are little %ore

    eFective at about 3'; eFiciency. o,ever hydrogen $uel cells can be u) to

    A6; eFicient =?>. Because o$ this versatility and eFiciency the *.S.

    4

  • 8/16/2019 Making Hydrogen a Competitive Alternative to Fossil Fuels Through Anaerobic Digestion of Waste

    5/21

    Ge)art%ent o$ &nergy is currently )er$or%ing research to %a e the% %ore

    eFicient and less e7)ensive to %anu$acture o)erate and %aintain.

    o,ever their research also includes hydrogen )roducing technologies as

    the cost o$ hydrogen is currently too e7)ensive to be co%)etitive ,ith $ossil

    $uels. The Ge)art%ent o$ &nergy esti%ates that a ilogra% o$ hydrogen

    ,hich is a))ro7i%ately e uivalent to one gallon o$ gasoline needs to cost

    bet,een H2.66 and H4.66 by the year 2626 =@>.

    1.3 Current Technologies

    Currently the only viable hydrogen )roduction technology is natural gas

    re$or%ing ,hich uses a t,o ste) a))roach to convert %ethane 8natural

    gas9 into hydrogen. In the frst ste) called stea%5%ethane re$or%ing

    natural gas is %i7ed ,ith ,ater va)or to create carbon %ono7ide and

    hydrogen gas. The carbon %ono7ide is then %i7ed ,ith ,ater va)or in

    ,hat is re$erred to as the ,ater5gas shi$t reaction ,hich converts the

    carbon %ono7ide and ,ater va)or into carbon dio7ide and hydrogen. This

    )rocess )roduces hydrogen at a cost o$ H3.?6 )er gallon o$ gasoline

    e uivalent 8gge9 dis)ensed. o,ever there are %any dra,bac s to this

    technology ,hich ,ill %a e costs )rohibitively e7)ensive to e7)and into the

    %ass %ar et =16>. Because o$ this the Ge)art%ent o$ &nergy is

    researching other technologies to create hydrogen through gasifcation o$

    bio%ass and coal electrolysis and %icrobial bio%ass conversion. &ach o$

    these technologies in their current states ho,ever are )rohibitively

    e7)ensive and %ore research %ust be )er$or%ed to %a e the% viable.

    '

  • 8/16/2019 Making Hydrogen a Competitive Alternative to Fossil Fuels Through Anaerobic Digestion of Waste

    6/21

    1.4 Objective

    In order to %a e hydrogen a co%)etitive $uel source to $ossil $uels research

    %ust be )er$or%ed to lo,er the cost o$ )roduction.

    " Current Technologies

    2.1 Natural Gas Re or!ing

    Currently @'; o$ all hydrogen is being )roduced in large central

    %anu$acturing )lants ,hich utiliEe natural gas re$or%ing technology. It

    ,or s by co%bining e7tre%ely hot ,ater va)or 8:66 ° C 5 1666 ° C9 ,ith the

    %ethane contained in natural gas at high )ressure. In the )resence o$ a

    )ro)er catalyst carbon %ono7ide and hydrogen is $or%ed in a )rocess

    called the stea%5%ethane re$or%ing reaction 8& uation 19.

    819 C 4 2 eat → C 3 2

    Ne7t the carbon %ono7ide is co%bined ,ith stea% in the )resence o$ a

    catalyst ,hich converts the carbon %ono7ide into carbon dio7ide and

    hydrogen 8& uation 29.

    829 C 2 → C 2 2 eat

    /inally i%)urities are re%oved $ro% the gas strea% leaving )ure hydrogen

    in a )rocess called )ressure5s,ing adsor)tion.

    This technology is used currently because natural gas is relatively

    ine7)ensive and even though carbon dio7ide is )roduced in the )rocess it

    is a relatively s%all a%ount ,hen co%)ared ,ith the co%bustion o$ $ossil

    $uels =11>. *n$ortunately there are dra,bac s to this technology. Ca)ital

    A

  • 8/16/2019 Making Hydrogen a Competitive Alternative to Fossil Fuels Through Anaerobic Digestion of Waste

    7/21

    costs to create satellite re$or%ers a,ay $ro% the large central )lants is too

    high to %eet )rice )er gge targets. #e$or%ing units are currently designed

    and built one at a ti%e leading to )rohibitively large and e7)ensive units.

    -dditionally the re$or%ing stations are too large $or urban settings. nce

    built the re$or%ing stations need e7cessive %aintenance and in )erson

    %onitoring leading to high o)eration costs. /inally control sa$ety and

    environ%ental )rotocols are needed to address concerns ,ithout escalating

    costs ,hile %eeting de%ands avoiding lea age and %ini%iEing e%issions

    =16>.

    2.2 "io!ass Gasifcation

    Bio%ass is considered to be any rene,able organic resource that can be

    used to )roduce hydrogen. &7a%)les o$ bio%ass include %unici)al solid

    ,aste ani%al ,aste agricultural ,aste and even cro)s gro,n $or the

    s)ecifc )ur)ose o$ being used $or energy use. Bio%ass gasifcation

    converts organic carbon based %atter into hydrogen carbon dio7ide and

    other gases by heating the bio%ass to over :66 ° C but not burning it. -

    controlled a%ount o$ o7ygen and stea% are used in this )rocess ,hich

    yields carbon %ono7ide carbon dio7ide hydrogen and other gases

    8& uation 39.

    839 CA 12 A 2 2 → C C 2 2 other gases

    Just li e natural gas re$or%ation the ne7t ste) is a ,ater5gas shi$t reaction

    to re%ove the )oisonous carbon %ono7ide $ro% the gas strea% 8& uation

    :

  • 8/16/2019 Making Hydrogen a Competitive Alternative to Fossil Fuels Through Anaerobic Digestion of Waste

    8/21

    29. -dsorbers or %e%branes fnally se)arate the hydrogen $ro% the gas

    strea% =12>.

    This technology is )ro%ising because o$ the abundance o$ bio%ass as a

    resource. -ccording to the *.S. Ge)art%ent o$ &nergy by the year 2636

    the *nited States ,ill )roduce over one billion dry tons o$ bio%ass that

    could )otentially be utiliEed $or gasifcation. Sources o$ this bio%ass

    include $orestland agricultural ,aste and energy cro)s =13>. -dditionally

    because )lants re%ove carbon dio7ide $ro% the at%os)here the carbon

    dio7ide )roduced during gasifcation is oFset ,hich results in a recycling o$

    carbon dio7ide ,hich lo,ers greenhouse gas e%issions.

    The challenges to bio%ass gasifcation center around high ca)ital costs $or

    )urchasing e ui)%ent and high costs associated ,ith bio%ass $eedstoc

    =12>.

    2.3 Coal Gasifcation

    Ki e bio%ass coal can be gasifed through the introduction o$ o7ygen and

    stea% under high te%)eratures. This results in synthesis gas ,hich

    consists o$ %ostly carbon %ono7ide and hydrogen 8& uation 49. nce

    again the ,ater5gas shi$t reaction 8& uation 29 converts the carbon

    %ono7ide to carbon dio7ide once the i%)urities o$ the synthesis gas are

    re%oved.

    849 C 6.? 2 2 → C C 2 2 other gases

    The abundance o$ coal resources in the *nited States %a es this technology

    attractive due to the lo, cost o$ the coal. o,ever coal gasifcation

    ?

  • 8/16/2019 Making Hydrogen a Competitive Alternative to Fossil Fuels Through Anaerobic Digestion of Waste

    9/21

    )roduces a large a%ount o$ carbon dio7ide. Gevelo)ing carbon ca)ture

    technologies to ensure the dangerous greenhouse gas is not released into

    the at%os)here during the )roduction )rocess is needed =14>.

    2.4 #lectrol$sis

    0ater can be bro en do,n into hydrogen and o7ygen by introducing it to

    electricity. This )rocess is called electrolysis. &lectrolysis is )ro%ising as

    it generates hydrogen ,ith no greenhouse gas e%issions. o,ever the

    electricity used to s)lit ,ater into its ele%ental co%)onents is usually

    generated using $ossil $uels. In addition to fnding green electricity sources

    ca)ital costs and hydrogen )ac aging costs are challenges that need to be

    overco%e $or electrolysis to beco%e a viable source o$ hydrogen =1'>.

    2.% Microbial "io!ass Conversion

    *nder anaerobic conditions so%e %icroorganis%s $er%ent organic %atter

    and create hydrogen. Because no light is needed by these %icroorganis%s

    this )rocess is called dar anaerobic $er%entation. This technology is

    attractive $or so%e o$ the sa%e reasons as bio%ass gasifcation bio%ass is

    an abundant resource and in %any cases it consists o$ ,aste )roducts

    ,hich can be obtained at little to no cost. -dditionally the %icroorganis%s

    use the bio%ass as an energy source so the bioreactors ,hich are used to

    generate hydrogen use little )o,er another cost saving attribute. o,ever

    hydrogen )roduction is slo, ,ith this technology. #esearch %ust be

    )er$or%ed to i%)rove %icrobial co%%unities reactor syste%s and

    $eedstoc sources to create higher yields =1A>.

    @

  • 8/16/2019 Making Hydrogen a Competitive Alternative to Fossil Fuels Through Anaerobic Digestion of Waste

    10/21

    # $roposed %ioreactor

    3.1 &'(o) *naerobic Slu+ge "lan,et Reactor

    Gar anaerobic $er%entation has great )otential to create lo, cost

    hydrogen. o,ever to ensure hydrogen costs stay lo, the )roduction

    )rocess %ust concentrate on using lo, cost $eedstoc and a bioreactor

    design ,hich uses lo, energy. The %ost co%%only utiliEed bioreactor

    design $or dar anaerobic $er%entation is the u)+o, anaerobic sludge

    blan et reactor 8/igure 49. This reactor is good $or lo, cost hydrogen

    )roduction because there is no %echanical stirring that %ust be )o,ered.

    Mi7ing o$ the substrate ,ith the %icroorganis%s is obtained through gas

    generation. -s the bacterial sludge $er%ents the organic substrate ,hich is

    )u%)ed into the reactor $ro% the botto% bubbles o$ biogas are $or%ed

    ,hich churn the li uid causing the desired %i7ing eFect and increases the

    rate o$ $er%entation =1:>. o,ever there are still challenges to )roducing

    lo, cost hydrogen using this technology. /eedstoc costs %ust be e)t lo,

    the bacterial co%%unity ,hich $er%ents the $eedstoc %ust be o)ti%iEed to

    increase )roduction rates and lo, energy reactor syste%s %ust be

    i%)le%ented to ee) o)erating costs lo,.

    16

  • 8/16/2019 Making Hydrogen a Competitive Alternative to Fossil Fuels Through Anaerobic Digestion of Waste

    11/21

    Figure &

    3.2 -oo+ aste as -ee+stoc,

    -naerobic $er%entative bacteria turn a carbon source usually a fve5carbon

    sugar li e glucose into hydrogen carbon dio7ide and organic acids acetic

    acid butyric acid and )ro)ionic acid. 0hen considering a $eedstoc $or

    biohydrogen 8hydrogen )roduced by living organis%s such as bacteria9

    )roduction it should be a %aterial that contains a high )ercentage o$ fve5

    carbon sugars. In addition because the $eedstoc is consu%ed there is a

    uni ue o))ortunity to use ,aste %aterial to )rovide a solution $or ,aste

    re%oval and storage. In a,aii )articularly on ahu $ood ,aste %a es u)

    the largest )ortion 812.:;9 o$ all ,aste that %a es its ,ay to ,aste

    )rocessing $acilities. ver 126 666 tons o$ $ood ,aste are )roduced each

    year on ahu %a ing it a )lenti$ul rene,able resource $or biohydrogen

    )roduction not to %ention ee)ing 126 666 tons o$ %atter out o$ the

    11

  • 8/16/2019 Making Hydrogen a Competitive Alternative to Fossil Fuels Through Anaerobic Digestion of Waste

    12/21

    island. -dditionally the local diet is rich in carbohydrates

    li e rice and tro)ical $ruits so the )otential $or biohydrogen )roduction

    $ro% $ood ,aste on ahu %ay be )otentially greater than that o$ %ainland

    *S-.

    3.3 /retreat!ent o Munici'al Slu+ge

    Many %unici)al ,aste ,ater treat%ent $acilities utiliEe bacterial sludge in

    their treat%ent )rocess but hydrogen is not a %a!or co%)onent o$ the

    biogas )roduced by this )rocess. Because o$ the )resence o$ %any %ethane

    )roducing %icroorganis%s in %unici)al sludge %ost o$ the hydrogen

    )roduced in the $er%entation )rocess gets converted into %ethane ,hich is

    a greenhouse gas that gives oF carbon dio7ide ,hen co%busted.

    /ortunately there are %any technologies that can be used to inhibit or

    eli%inate %ethanogenic %icroorganis%s. In %ost cases the technologies

    )rovide harsh conditions $or the %icroorganis%s in the sludge to induce

    s)ore $or%ation. Certain %icroorganis%s create s)ores ,hen )laced in an

    environ%ent in ,hich they cannot survive. The s)ores they create

    ho,ever can survive very harsh conditions and i$ conditions return to a

    state in ,hich the %icroorganis%s can thrive the s)ores hatchD into a ne,

    version o$ the original. Methanogenic bacteria have sho,n they are non5

    s)ore $or%ing and there$ore are illed in such harsh conditions ,hile %any

    hydrogenic bacteria are s)ore $or%ing. By creating such harsh conditions

    the %ethanogenic bacteria )erish leaving the desirable hydrogenic bacteria

    12

  • 8/16/2019 Making Hydrogen a Competitive Alternative to Fossil Fuels Through Anaerobic Digestion of Waste

    13/21

    to survive and thrive. Theoretically a sludge that has been )retreated in

    this %anner should )roduce biogas rich in hydrogen.

    3.3.1 0eat Shoc, Treat!ent

    eat Shoc Treat%ent 8 ST9 is the %ost co%%only used )retreat%ent

    %ethod. It uses heat to create a harsh environ%ent ,hich induces s)ore

    creation by hydrogenic bacteria "acillus and Clostri+iu! ,hile illing oF

    %ethanogenic bacteria. o,ever as ,ith %any )retreat%ent %ethods that

    rely on inducing s)orulation other s)ore )roducing bacteria survive the

    )retreat%ent )rocess ,hich )roduces a %i7ed culture that includes

    acetogenic bacteria such as "acterioi+es and #ubacteriu! ,hich utiliEe

    hydrogen =1@>. Most o$ the ti%e an increase o$ hydrogen yield is seen a$ter

    ST co%)ared to an untreated control ,ith a %a7i%u% re)orted yield o$

    2.3 %ol hydrogen )er %ol glucose. =26>. Ty)ically sludge is )retreated at a

    te%)erature bet,een @65166 ° C $ro% any,here bet,een 16%in to 1h =21>.

    3.3.2 *ci+ *l,ali Treat!ent

    Because %ethanogenic bacteria survive at neutral ) the addition o$ acid

    or al ali to )retreat sludge has been investigated. Ty)ically hydrogen

    )roducing bacteria can survive at a ,ider ) range than %ethanogenic

    bacteria. Because s)ore $or%ers are not the only bacteria to survive a

    %ore diverse %icrobial co%%unity e7ists a$ter acid al ali )retreat%ent =26>.

    The %ost co%%on acidic )retreat%ent uses Cl 2S 4 N 3 and Cl 4

    =22 23> ,ith Na being the %ost )o)ular al aline treat%ent %ethod =24>.

    13

  • 8/16/2019 Making Hydrogen a Competitive Alternative to Fossil Fuels Through Anaerobic Digestion of Waste

    14/21

    Ty)ically the )retreat%ent lasts $or 24h =2'> ,ith a %a7i%u% observed

    yield o$ 1.' %ol hydrogen )er %ol glucose =2A>.

    3.3.3 *eration

    The )ur)ose o$ aeration is to a))ly o7idative stress to obligate anaerobes

    ,hich causes the% to die. Most %ethanogenic bacteria are obligate

    anaerobes ho,ever %any hydrogen )roducing bacteria are also obligate

    anaerobes ,hich %a es this %ethod rather ineFicient. -$ter aeration $or

    24 hours %a7i%u% hydrogen yield ,as very lo, at 6.: %ol hydrogen )er

    %ol glucose =2A>. o,ever aeration has sho,n a very large acetate to

    butyrate ratio co%)ared ,ith other %ethods 826.'? L 6.2'9 =24>. This is

    signifcant because the acetate )ath,ay )roduces $our %oles o$ hydrogen to

    every %ole o$ glucose ,hile the butyrate )ath,ay only )roduces t,o.

    -dditionally because o$ the diFerent ind o$ stress this treat%ent )laces on

    the sludge co%)ared to other %ethods it results in a diFerent %icrobial

    co%%unity. Most )hysical )retreat%ents sho, Clostri+iu! s)). as the

    do%inant s)ecies a$ter )retreat%ent but aeration sees #nterobacter s)).

    and lebsiella s)) =2A>. This )rovides a uni ue o))ortunity to co%bine

    sludge that has been )retreated ,ith o7idative stress ,ith heat shoc ed

    sludge $or e7a%)le %a ing $or a %ore robust %icrobial co%%unity.

    3.3.4 &ltraviolet rra+iation

    *ltraviolet irradiation bo%bards the sludge ,ith ,avelengths $ro% 16n% to

    3?6n% creating an environ%ent ,hich sti%ulates s)orulation o$ hydrogenic

    bacteria and inhibition or eli%ination o$ %ethanogenic bacteria. This

    14

  • 8/16/2019 Making Hydrogen a Competitive Alternative to Fossil Fuels Through Anaerobic Digestion of Waste

    15/21

    %ethod is )roven to increase hydrogen yield by 6.3@ $old co%)ared to

    untreated sludge ,hen irradiated $or 1' %in =2:>. The co%)lication o$ this

    %ethod is that sludge is usually dar and o)a ue ,hich bloc s the * light

    $ro% )enetrating $arther than !ust the sur$ace %a ing this an ineFicient

    %ethod. n the other hand this %ethod )resents a uni ue )ossibility to

    ee) costs do,n. Solar irradiation could )otentially be used as a substitute

    $or * irradiation through electric )o,ered la%)s. #esearch %ust be

    )er$or%ed to deter%ine the )ro)er )ara%eters $or this %ethod such as

    translucence o$ sludge de)th o$ sludge and ti%e o$ e7)osure to solar

    irradiation.

    3.4 !'ortance o Genetic Se uencing

    "enetic se uencing can be an i%)ortant tool in %a7i%iEing hydrogen

    )roduction ,hen utiliEing )retreat%ent technologies. ne se uencing

    techni ue called bar coding can be a valuable tool in identi$ying the

    %icrobial co%%unity o$ )retreated %unici)al sludge. Bar coding utiliEes

    s)ecifc areas o$ the geno%e ,hich are co%)letely uni ue to each s)ecies o$

    bacteria. nce such area o$ the geno%e is the 1AS region o$ the riboso%al

    #N- =2?>. Isolating this region is uite %anageable and it can be a%)lifed

    through (C# easily so the se uence can be obtained %ulti)le ti%es over to

    ensure accuracy. -nother se uencing techni ue that can be use$ul is ,hole

    geno%e se uencing. -lthough it is a longer %ore e7)ensive and diFicult

    )rocess it yields %ore accurate results because entire geno%es are being

    co%)ared to database in$o not !ust a short se uence li e those utiliEed in

    1'

  • 8/16/2019 Making Hydrogen a Competitive Alternative to Fossil Fuels Through Anaerobic Digestion of Waste

    16/21

    bar coding. By using genetic se uencing techni ues to identi$y the

    %icrobial co%%unity o$ )retreated sludge a )ossible correlation can be

    %ade by co%)aring the hydrogen )roduction o$ each ty)e o$ )retreated

    sludge ,ith the %icrobial co%%unity )resent in the sludge. This ,ay

    individual s)ecies o$ bacteria can be identifed as vital to the hydrogen

    )roducing )rocess. nce the i%)ortant bacteria are identifed an o)ti%al

    %icrobial co%%unity %ay be designed to %a7i%iEe hydrogen )roduction.

    & Future 'esearch

    Ma7i%iEing hydrogen yield through dar anaerobic $er%entation ,hile

    %ini%iEing cost is a $uture reality. Many )ara%eters %ust be researched

    be$ore this technology is ready $or )roduction on an industrial scale. The

    )otential %icrobial co%%unities that could be utiliEed are al%ost infnite

    and research %ust be done to identi$y not only the %ost eFicient bacterial

    co%%unity $or hydrogen )roduction but also the right co%%unity $or the

    s)ecifc $eedstoc being considered. #esearch %ust also be )er$or%ed to

    identi$y lo, cost $eedstoc o)tions and ,hether they are better $or dar

    anaerobic $er%entation as a )ure $eedstoc or one that has been %i7ed ,ith

    another $or%. #eactor designs %ust be researched to o)ti%iEe hydrogen

    )roduction ,hile ee)ing o)erating and ca)ital costs lo,. )ti%al

    $eedstoc concentration #T te%)erature and ) %ust be identifed.

    -dditionally lo, energy reactor syste%s %ust be integrated to re%ove and

    )uri$y the hydrogen and drive the syste%.

    1A

  • 8/16/2019 Making Hydrogen a Competitive Alternative to Fossil Fuels Through Anaerobic Digestion of Waste

    17/21

    ( Conclusion

    0ith research being )er$or%ed to decrease the cost o$ hydrogen

    )roduction biohydrogen is a )ro%ising technology. Biohydrogen $ro%

    ,aste is even %ore enticing because it solves t,o )otential )roble%s

    ,aste %anage%ent and $eedstoc cost. (retreat%ent o$ %unici)al sludge

    to %a7i%iEe biohydrogen )roduction can be utiliEed to this end. o,ever

    %ore research %ust be )er$or%ed to o)ti%iEe hydrogen yields and drive

    hydrogen costs do,n. By using genetic se uencing techni ues %ore

    insight can be gained into the co%%unity o$ %icroorganis%s that %ay be

    best $or hydrogen )roduction. This techni ue can )otentially be used to

    o)ti%iEe %icrobial co%%unities $or each ty)e o$ $eedstoc in order to use

    ine7)ensive %aterials or even ,aste to %a e hydrogen even %ore

    aFordable. Ko, energy bioreactors such as an u)+o, anaerobic sludge

    blan et reactor can be used to ee) o)erating costs do,n. o,ever

    research %ust be )er$or%ed to identi$y the o)ti%al o)erating s)ecifcations

    and reactor syste%s ,hile ee)ing energy invest%ent lo,. I$ hydrogen can

    beco%e a lo,er cost alternative to burning $ossil $uels $or energy it %ay be

    utiliEed %ore ta ing a,ay the need $or $ossil $uels and turning to a %ore

    sustainable and clean source o$ energy. Microbial bio%ass conversion could

    be the %eans to this end.

    1:

  • 8/16/2019 Making Hydrogen a Competitive Alternative to Fossil Fuels Through Anaerobic Digestion of Waste

    18/21

    'eferences)=1> I(CC 8Intergovern%ental (anel on Cli%ate Change9. 2613. Cli%ate

    change 2613L The )hysical science basis. 0or ing "rou) I contributionto the I(CC /i$th -ssess%ent #e)ort. Ca%bridge *nited ingdo%LCa%bridge *niversity (ress.

    1?

  • 8/16/2019 Making Hydrogen a Competitive Alternative to Fossil Fuels Through Anaerobic Digestion of Waste

    19/21

    =2> Boden T.-. Marland ". and -ndres #.J. 8261'9.National C 2&%issions $ro% /ossil5/uel Burning Ce%ent Manu$acture and "as/laringL 1:'152611 Carbon Gio7ide In$or%ation -nalysis Center a#idge National Kaboratory *.S. Ge)art%ent o$ &nergy doi16.3334 CGI-C 66661O 261'.

    =3> Boden T.-. Marland ". and -ndres #.J. 8261'9. "lobal #egional andNational /ossil5/uel C 2&%issions. Carbon Gio7ide In$or%ation

    -nalysis Center a #idge National Kaboratory *.S. Ge)art%ent o$&nergy doi 16.3334 CGI-C 66661O 261'.

    =4> I(CC 2614L Su%%ary $or (olicy%a ers. InL Cli%ate Change 2614LMitigation o$ Cli%ate Change. Contribution o$ 0or ing "rou) III to the/i$th -ssess%ent #e)ort o$ the Intergovern%ental (anel on Cli%ateChange =&denho$er . #. (ichs5Madruga P. So ona &. /arahani S.

    adner . Seyboth -. -dler I. Bau% S. Brunner (. &ic e%eier B.rie%ann J. Savolainen S. SchlQ%er C. von Stecho, T. R,ic el and J.C.

    Min7 8eds.9>. Ca%bridge *niversity (ress Ca%bridge *nited ingdo%and Ne, Por NP *S-.

    ='> "#&&T Trans)ortation /uel Cycle -nalysis Model "#&&T 1.?bdevelo)ed by -rgonne National Kaboratory -rgonne IK releasedSe)te%ber ' 266?. htt)sL greet.es.anl.gov .

    =A> &nergy (olicy -ct. *.S. ".(. . 266'.

    =:> ydrogen and ur &nergy /uture /act Sheet.htt)L energy.gov sites )rod fles 2614 63 $16 hydrogenenergy$utureO,eb.)d$ .

    =?> *.S. Ge)art%ent o$ &nergy &nergy In$or%ation -d%inistrationSu))le%ental tables to the -nnual &nergy utloo 66' trans)ortationde%and Sector D table : 8 66'9 '.

    =@> G & ydrogen and /uel Cells (rogra% #ecord 1166:L ydrogenThreshold Cost Calculation.

    =16> *.S. G#I & (artnershi). ydrogen (roduction Technical #oad%a).2613.htt)L energy.gov sites )rod fles 2614 62 $? h)ttOroad%a)O!une2613.)d$ .

    1@

    https://greet.es.anl.gov/http://energy.gov/sites/prod/files/2014/03/f10/hydrogenenergyfuture_web.pdfhttp://energy.gov/sites/prod/files/2014/03/f10/hydrogenenergyfuture_web.pdfhttp://energy.gov/sites/prod/files/2014/02/f8/hptt_roadmap_june2013.pdfhttp://energy.gov/sites/prod/files/2014/03/f10/hydrogenenergyfuture_web.pdfhttp://energy.gov/sites/prod/files/2014/03/f10/hydrogenenergyfuture_web.pdfhttp://energy.gov/sites/prod/files/2014/02/f8/hptt_roadmap_june2013.pdfhttp://energy.gov/sites/prod/files/2014/02/f8/hptt_roadmap_june2013.pdfhttps://greet.es.anl.gov/

  • 8/16/2019 Making Hydrogen a Competitive Alternative to Fossil Fuels Through Anaerobic Digestion of Waste

    20/21

    =11> PG# "&N (# G*CTI NL N-T*#-K "-S #&/ #MIN".htt)L energy.gov eere $uelcells hydrogen5)roduction5natural5gas5re$or%ing .

    =12> PG# "&N (# G*CTI NL BI M-SS "-SI/IC-TI N.

    htt)L energy.gov eere $uelcells hydrogen5)roduction5bio%ass5gasifcation .

    =13> *.S. Ge)art%ent o$ &nergy. 2611. *.S. Billion5Ton *)dateL Bio%assSu))ly $or a Bioenergy and Bio)roducts Industry. #.G. (erlac and B.J.Sto es 8Keads9 #NK TM52611 224. a #idge National Kaboratory

    a #idge TN. 22:).

    =14> PG# "&N (# G*CTI NL C -K "-SI/IC-TI N.htt)L energy.gov eere $uelcells hydrogen5)roduction5coal5gasifcation .

    =1'> PG# "&N (# G*CTI NL &K&CT# KPSIS.htt)L energy.gov eere $uelcells hydrogen5)roduction5electrolysis .

    =1A> PG# "&N (# G*CTI NL MIC# BI-K BI M-SS C N SI N.htt)L energy.gov eere $uelcells hydrogen5)roduction5%icrobial5bio%ass5conversion .

    =1:> Tilley &. *lrich K. K thi C. #ey%ond (h. Rurbr gg C. 826149Co%)endiu% o$ Sanitation Syste%s and Technologies 5 82nd #evised&dition9. S,iss /ederal Institute o$ - uatic Science and Technology8&a,ag9 Guebendor$ S,itEerland. ISBN @:?535@6A4?45':56.

    =1?> #.0. Bec 266A 0aste CharacteriEation Study City and County o$onolulu.

    =1@> (endyala B. et al. 826129. U(retreating %i7ed anaerobic co%%unities$ro% diFerent sourcesL Correlating the hydrogen yield ,ith hydrogenaseactivity and %icrobial diversity.U International Journal o$ ydrogen&nergy 3:81:9L 121:'5121?A.

    =26> S . Thong et al. 8266@9. U&valuation o$ %ethods $or )re)aringhydrogen5)roducing seed inocula under ther%o)hilic condition by)rocess )er$or%ance and %icrobial co%%unity analysis.U BioresourTechnol 166829L @6@5@1?.

    =21> Bundhoo M. -. et al. 8261'9. U&Fects o$ )re5treat%ent technologieson dar $er%entative biohydrogen )roductionL - revie,.U J &nvironManage 1':L 2654?.

    26

    http://energy.gov/eere/fuelcells/hydrogen-production-natural-gas-reforminghttp://energy.gov/eere/fuelcells/hydrogen-production-natural-gas-reforminghttp://energy.gov/eere/fuelcells/hydrogen-production-biomass-gasificationhttp://energy.gov/eere/fuelcells/hydrogen-production-biomass-gasificationhttp://energy.gov/eere/fuelcells/hydrogen-production-coal-gasificationhttp://energy.gov/eere/fuelcells/hydrogen-production-electrolysishttp://energy.gov/eere/fuelcells/hydrogen-production-microbial-biomass-conversionhttp://energy.gov/eere/fuelcells/hydrogen-production-microbial-biomass-conversionhttp://energy.gov/eere/fuelcells/hydrogen-production-natural-gas-reforminghttp://energy.gov/eere/fuelcells/hydrogen-production-natural-gas-reforminghttp://energy.gov/eere/fuelcells/hydrogen-production-biomass-gasificationhttp://energy.gov/eere/fuelcells/hydrogen-production-biomass-gasificationhttp://energy.gov/eere/fuelcells/hydrogen-production-coal-gasificationhttp://energy.gov/eere/fuelcells/hydrogen-production-electrolysishttp://energy.gov/eere/fuelcells/hydrogen-production-microbial-biomass-conversionhttp://energy.gov/eere/fuelcells/hydrogen-production-microbial-biomass-conversion

  • 8/16/2019 Making Hydrogen a Competitive Alternative to Fossil Fuels Through Anaerobic Digestion of Waste

    21/21

    =22> Kee .M. Song J. . ,ang S.J. 8266@9. &Fects o$ acid )re5treat%ent on bio5hydrogen )roduction and %icrobial co%%unitiesduring dar $er%entation. Bioresour. Technol. 166 14@1514@3.

    =23> Cheong G. P. and C. K. ansen 8266A9. UBacterial stress enrich%ent

    enhances anaerobic hydrogen )roduction in cattle %anure sludge.U -))lMicrobiol Biotechnol :2849L A3'5A43.

    =24> Chang S. Ki J. Kiu /. 826119. &valuation o$ diFerent )retreat%ent%ethods $or )re)aring hydrogen5)roducing seed inocula $ro% ,asteactivated sludge. #ene,able &nergy 3A. 1'1:51'22.

    =2'> an &. 826139. U&Fects o$ )retreat%ents o$ anaerobic sludge andculture conditions on hydrogen )roductivity in dar anaerobic$er%entation.U #ene,able &nergy 4@L 22:5231.

    =2A> 0ong P. M. et al. 826149. U- revie, o$ sustainable hydrogen)roduction using seed sludge via dar $er%entation.U #ene,able andSustainable &nergy #evie,s 34L 4:154?2.

    =2:> 0ang /ang M /ang R Bu . &Fects o$ sludge )retreat%ents andorganic acids on hydrogen )roduction by anaerobic $er%entation.Bioresour. Technol. 266: 161 ?:315'.

    =2?> Kaothanachareon T. et al. 826149. U-nalysis o$ %icrobial co%%unityada)tation in %eso)hilic hydrogen $er%entation $ro% $ood ,aste bytagged 1AS r#N- gene )yrose uencing.U J &nviron Manage 144L 14351'1.


Recommended