Lub Hnub Ob Txoj Kev rau Lub Hwj Chim: Nkag siab txog Hnub Ci Hydrogen Ntau Lawm thiab Lub Hwj Chim Hnub Ci

Thaum cov tib neeg feem ntau xav txog hluav taws xob hnub ci xws li ntawm photovoltaic panels siv lub hnub ci rau lub zog; Muaj ntau ntau txoj hauv kev uas koj tuaj yeem tau txais txiaj ntsig los ntawm lub hnub dua li cov duab hluav taws xob photovoltaic xwb. Piv txwv li, koj tuaj yeem siv lub hnub los tsim cov roj hydrogen huv thiab tsim cov khoom siv hluav taws xob- teev lub zog los ntawm tshav kub. Muaj ob peb lub tswv yim tshiab tshiab uas tau thawb lub hnab ntawv ntawm lub hnub ci zog: hydrogen los ntawm lub hnub ci zog qhov chaw thiab lub hnub ci zog (CSP).

Hydrogen hu ua "roj ntawm tag kis" rau ntau yam. Hydrogen muaj kwv yees li 142 MJ / kg lub zog cov ntsiab lus, thiab yog tias koj siv hydrogen hauv cov roj cell, tsuas yog cov emissions uas tsim los ntawm dej. Txawm li cas los xij, kev tsim cov roj hydrogen ntau kom huv si, tseem yog qhov nyuaj rau kev tsim cov hydrogen. Ib txoj hauv kev los daws qhov teeb meem no yog siv lub hnub ci los faib dej raws li kev tsim cov hydrogen, cov txheej txheem no muaj pes tsawg lub tsev cog khoom roj emissions.

Muaj peb yam tseem ceeb ntawm hydrogen ntau lawm los ntawm lub hnub ci zog uas tam sim no nyob rau ntau theem kom loj hlob:

Thawj thev naus laus zis (feem ntau paub tab) siv photovoltaic (PV) panels txuas nrog electrolyzers. Electrolyzers yog cov khoom siv hluav taws xob uas siv hluav taws xob thiab hloov dej mus rau hydrogen thiab oxygen los ntawm kev siv hluav taws xob thiab hloov hluav taws xob. PV systems yog tsim thiab yooj yim; PV systems yog heev modular thiab txhim khu kev qha; Thaum PV thiab electrolyzer txuas nrog yam tsis muaj lub zog hloov pauv, STH kev hloov pauv kev ua haujlwm ntawm tag nrho cov kab ke tau mus txog qhov kev txwv theoretical.

Kev tshawb fawb qhia tau hais tias cov txheej txheem PV tseem ceeb ua tau zoo dua li cov qauv qub. Siv InGaP/GaAs/Ge hlwb nyob rau hauv 750 hnub concentration, cov kws tshawb fawb tau ua tiav STH cov txiaj ntsig ntawm 18-21% nrog cov nqi tsim khoom ntawm 0.8-1.0 litres ntawm hydrogen ib feeb ib square meter ntawm cheeb tsam module. Cov pa hluav taws xob silicon modules nyob rau hauv ib lub hnub, los ntawm kev sib piv, ua tiav tsuas yog li 9.4% STH efficiency nrog cov nqi ntau lawm nyob ib ncig ntawm 0.3 L / min·m². Qhov no sawv cev rau kev ua tau zoo ntawm 1.5 mus rau 3 zaug rau cov tshuab ua kom muaj zog.

Dej electrolysis muaj qhov siv tau zoo ntawm 70-80%, ua qhov kev xaiv no txaus siab dua thaum xav txog cov nqi hluav taws xob txuas ntxiv mus rau yav tom ntej. Tib qhov kev sib tw loj tam sim no yog tus nqi siab ntawm electrolyzers thiab qhov tsis muaj peev xwm ntawm lub hnub ci hluav taws xob, uas ua rau kev xav tau kev sib koom ua ke rau hauv lub cev.

Cov tshuab Photoelectrochemical (PEC) siv cov kev sib xyaw ua ke ntau dua li cov txheej txheem dhau los rau electrolysis ntawm dej los ntawm thawj zaug tsim hluav taws xob thiab tom qab ntawd siv lub zog ntawd los tsim cov hydrogen los ntawm dej. PECs siv cov khoom siv semiconductor submerged hauv dej, uas muaj peev xwm nqus tau lub teeb los ntawm lub hnub thiab hloov nws ncaj qha mus khaws lub zog tshuaj nyob rau hauv daim ntawv ntawm hydrogen los ntawm electrolysis ntawm dej. Qhov no tshwm sim thaum lub teeb hits lub semiconductor tsim khub ntawm electrons / qhov. Cov electrons nyob rau hauv lub semiconductor mechanism txo protons los tsim hydrogen; cov qhov tsim yuav oxidize cov dej molecules tsim oxygen.

PECs tau tshawb fawb thawj zaug kwv yees li 50 xyoo dhau los los ntawm Shinichiro Fujishima thiab Honda thaum lawv pom tias titanium dioxide (TiO2) electrode tuaj yeem faib H2O rau hauv H2 thiab O2 thaum txuas nrog platinum cathode / alloy thiab illuminated nrog UV teeb. (Qhov no yog qhov hu ua "Honda-Fujishima effect")

Tam sim no, PEC systems muaj qhov zoo nkauj, tsim qauv nrog lub peev xwm ua tiav lub hnub ci ncaj qha - mus rau - hydrogen hloov dua siab tshiab los ntawm ib qho yooj yim thiab elegant mechanism. Txawm hais tias cov qauv tsim zoo li no, PEC thev naus laus zis tseem nyob hauv nws cov me nyuam mos thiab yuav tsum kov yeej qee qhov teeb meem tseem ceeb ua ntej kev lag luam tuaj yeem tshwm sim, xws li kev ua haujlwm qis hauv lawv lub hnub ci - mus rau -hydrogen hloov dua siab tshiab, degradation ntawm cov khoom siv los tsim PEC hlwb, thiab scalability ntawm kev ua tau zoo. Yog li, kev tshawb fawb tsis tu ncua tau ua rau cov khoom siv siab heev thiab nanostructured photoelectrodes tsim los daws cov teeb meem no.

Ib txoj hauv kev muaj tswv yim ntau dua ntawm kev ua qhov no yog siv cov khoom siv nanoscale me me semiconductor (tseem hu ua quantum dots) dispersed nyob rau hauv ib qho nruab nrab aqueous li photocatalysts. Thaum illumination nrog lub hnub ci lawv tsim hluav taws xob (thiab qhov) uas tuaj yeem txav mus rau qhov sib cuam tshuam ntawm cov khoom thiab pib cov oxidation thiab txo qis ib nrab cov tshuaj tiv thaiv hu ua hydrogen evolution thiab oxygen evolution feem.

Ib qho particle photocatalyst system, lossis ib qho -cov kauj ruam excitation system, yuav tsum kom lub bandgap ntawm lub semiconductor straddles ob qho tib si hydrogen evolution muaj peev xwm thiab cov pa oxygen evolution peev xwm. Kuj tseem muaj ob -ib feem photocatalyst system los yog "Z-scheme" photocatalyst configuration qhov twg ob lub photocatalysts sib txawv yog khi ua ke los ntawm ib tug tshuaj nruab nrab (xws li redox ob peb) kom cov dej splitting tshwm sim nyob rau hauv ob qho tib si kauj ruam los yog ib nrab cov tshuaj tiv thaiv. Qhov no txo ​​qis lub zog xav tau rau txhua qhov tshuaj tiv thaiv, thaum tso cai rau siv ntau lub teeb pom kev zoo.

Cov kev ua tsis ntev los no qhia tau tias muaj peev xwm ntawm txoj hauv kev no. Ib pab neeg tshawb fawb Suav coj los ntawm Liu Gang ntawm Lub Tsev Haujlwm ntawm Kev Tshawb Fawb Hlau tau txhim kho titanium dioxide- cov khoom siv photocatalytic tseem ceeb- los ntawm kev ntxiv cov scandium los ntawm "kev hloov kho cov qauv" thiab "kev hloov pauv." Lub scandium ions haum zoo rau hauv cov khoom siv lub lattice, tshem tawm "trap zones" uas ib txwm snag electrons, thiab reshape lub siv lead ua nto los ua "electronic highways" uas qhia cov neeg nqa khoom zoo.

Cov khoom siv kho kom zoo siv ntau dua 30% ntawm lub teeb ultraviolet thiab ua tiav cov khoom siv hydrogen nyob rau hauv simulated hnub ci 15 npaug ntau dua li cov qauv ua ntej. Raws li pab pawg tshawb fawb, ib qho -square-meter photocatalytic vaj huam sib luag tuaj yeem tsim tau li ntawm 10 litres ntawm hydrogen ib hnub nyob rau hauv tshav ntuj.

Thaum cov particle photocatalysis tseem nyob hauv chav kuaj, nws lub peev xwm rau kev xa tawm loj - yog qhov nyuaj. Hmoov- daim ntawv photocatalysts yooj yim dua rau kev lis kev cai thiab ntau dua rau kev sib kis thoob plaws thaj chaw loj uas siv cov txheej txheem pheej yig piv rau PV-electrolysis lossis PEC systems.

Concentrated Solar Power (CSP) siv txoj hauv kev sib txawv rau kev siv lub hnub. Tsis txhob hloov lub teeb ncaj qha mus rau hauv hluav taws xob, CSP siv cov iav tsom iav kom pom lub hnub ci, tsim kom muaj - kub kub, thiab ces tsav cov pa turbines los tsim hluav taws xob.

Lub tswv yim tseem ceeb yog qhov yooj yim heev. Heliostats, los yog kev npaj ntawm daim iav, ua raws li lub hnub txoj kev kawm txhua hnub thiab xav txog lub hnub lub rays mus rau ib tug collector nyob rau sab saum toj ntawm ib tug pej thuam. Qhov kev xav ntawm lub hnub ci no yog siv los ua kom sov cov dej ua haujlwm mus rau qhov kub siab heev, thiab thaum tshav kub kub ua haujlwm, cov dej ua haujlwm kub yog siv rau hauv cov tiam ntawm chav uas yuav tig lub turbine tsav lub tshuab hluav taws xob.

Lub peev xwm los muab cov thermal zog cia rau hauv CSP system yog qhov ua rau CSP ntawm tus nqi zoo li no. Cov cua kub uas ua los ntawm cov txheej txheem ntawm kev tsom mus rau lub hnub lub rays tuaj yeem ntes thiab khaws cia rau ntau teev, txhais tau hais tias kev tsim hluav taws xob los ntawm CSP system tuaj yeem tshwm sim ntev tom qab hnub poob. Cov khoom xa tuaj ntawm CSP- yog, thaum koj xav tau hluav taws xob koj tuaj yeem tsim tau nws- yog qhov txawv ntawm CSP los ntawm PV hnub ci tshuab, uas tsis tsim hluav taws xob thaum nws pib huab cua lossis hmo ntuj.

Cov thev naus laus zis pom nyob rau sab saum toj ntawm lub pyramid tam sim no (Gemasolar hauv Spain, Crescent Dunes hauv Nevada thiab Noor III) nta cov kua ntsev molten siv tsis yog rau kev hloov cua sov, tab sis kuj khaws cia lub zog. Tag nrho peb lub tshuab tau ua tiav qhov kev muaj peev xwm ua haujlwm tsis tu ncua rau tag nrho 24 teev thaum tuav ntau tshaj 15 teev ntawm lub zog cia nrog cov kua ntsev molten ib leeg.

US Department of Energy's Concentrated Solar Power Generation 3 (CSP Gen3) qhov kev pab cuam yuav ua kom cov thev naus laus zis no dhau ntawm CSP kev lag luam uas twb muaj lawm. Ib qho ntawm cov qauv tsim tau tshawb nrhiav nyob rau hauv CSP Gen3 qhov kev pab cuam yog "Liquid Pathway", uas siv cov nqi qis dua - cov kua chlorides ua lub zog cia, thiab cov kua sodium tau txais ntawm kwv yees li 740oC los hloov cov cua sov mus rau supercritical carbon dioxide (sCO2) lub voj voog hluav taws xob. Tag nrho sCO2 lub voj voog hluav taws xob yuav ua haujlwm ntawm qhov ua tau zoo dua li cov khoom siv niaj hnub Rankine hom voj voog, thiab.

Qhov no sawv cev rau kev nce qib tseem ceeb los ntawm cov nroj tsuag tam sim no, uas feem ntau ua haujlwm ntawm thaj tsam 565℃siv nitrate ntsev. Kev ua haujlwm siab dua ua kom muaj txiaj ntsig zoo dua thiab txo tus nqi ntawm lub zog qis dua -Gen3 lub hom phiaj yog qis dua $ 60 toj ib megawatt- teev.

Ob - tank molten ntsev system tso cai rau cov neeg ua haujlwm kom xa cov ntsev los ntawm lub hnub ci kom them nyiaj (tso cua sov lub tank "kub"), thiab tom qab ntawd los ntawm cov khoom siv hluav taws xob los tsim cov pa thaum yuav tsum tau tso tawm. Lub thermal efficiency ntawm kev cia nws tus kheej yog siab - khaws cov cua sov hauv insulated tso tsheb hlau luam tshaj 90% efficiency rau txhua hnub.

Txawm li cas los xij, lub voj voog - kev ua haujlwm zoo rau kev cia hluav taws xob, txawm li cas los xij, ntsib qhov kev txwv tseem ceeb. Hloov cov cua sov rov qab mus rau hluav taws xob los ntawm chav turbines feem ntau ua tiav tsuas yog 35-42% thermal efficiency. Txawm tias qib siab heev supercritical CO2 turbines tawm tsam kom tshaj 50%. Rau kev sib piv, lithium - roj teeb ion niaj zaus tshaj 85% kev ua haujlwm mus ncig.

Qhov kev nplua no txhais tau hais tias CSP yog qhov zoo tshaj plaws rau cov ntawv thov uas qhov thermal cia tus nqi -ntev ntev, tus nqi qis ib kilowatt- teev cia, thiab muaj peev xwm muab cov cim synchronous - ntau dua qhov poob ntawm kev hloov pauv. Rau daim phiaj- teev cia ntev 6-12 teev, kev lag luam tseem tuaj yeem ua haujlwm.

Txoj kev loj hlob ntawm cov khoom siv hluav taws xob tauj dua tshiab los tsim hluav taws xob, CSP qhov kev pab cuam rau decarbonization ntawm cov txheej txheem kev lag luam, thiab kev tsim cov thermal cia tau tso cai rau CSPs muab kev pabcuam tshaj li hluav taws xob xwb. Ntau cov txheej txheem kev lag luam yuav tsum tau ua kom tas mus li, ntawm -xav tau cov khoom siv hluav taws xob lossis hluav taws xob ncaj qha hauv qhov kub ntawm 300 txog 550 degrees Celsius, uas suav nrog cov txheej txheem xws li kev tsim cov ntawv, roj refining, thiab kev ua tshuaj.

Los ntawm kev siv loj heev - nplai molten ntsev thermal zog cia tshuab, CSPs tuaj yeem ua tiav lub hom phiaj no los ntawm kev muab cov txheej txheem chav thiab/lossis cua sov rau cov ntawv thov kev lag luam raws li qhov xav tau tiag tiag - sijhawm. Lub peev xwm loj ntawm cov molten no - ntsev thermal lub zog cia tshuab kuj muaj tus nqi zoo heev - siv tau rau cov roj teeb hluav taws xob, uas muaj nqi tsawg dua $ 35 ib kilowatt - teev (kWh) ntawm cov khoom siv hluav taws xob thermal.

Muaj cov txheej txheem ntxiv rau kev siv lub hnub lub zog, suav nrog kev tsim cov hnub ci hydrogen thiab cov hnub ci zog (CSP). Lub hnub lub zog yog hloov mus rau hauv tshuaj lom neeg roj (hydrogen) ntawm photovoltaic (PV) electrolysis thiab photocatalytic systems uas tuaj yeem khaws cia tsis tu ncua. Hydrogen tuaj yeem siv rau kev thauj mus los, kev lag luam, thiab kev tsim hluav taws xob. Xwb, CSP siv lub hnub ci los ua kom sov. CSP tom qab ntawd hloov lub zog thermal rau hauv hluav taws xob rau kev xa tawm (kev txiav txim) xa tuaj.

Kev nce qib nrawm hauv ob lub thev naus laus zis tau tshwm sim. Ua kom lub hnub ci ntxiv - mus rau -hydrogen conversion efficiency tau los ntawm kev txhim kho cov ntaub ntawv thiab kev sib koom ua ke; CSP txuas ntxiv thawb rau kev ua haujlwm siab dua thiab cov nqi qis dua. Thaum sib xyaw ua ke, PV electrolysis thiab CSP tso cai rau lub hnub ci- lub ntiaj teb lub zog uas tsis tsuas yog lub hnub muab lub zog rau qhov xav tau tab sis kuj tsim tau yooj yim - khaws cov roj los muab lub zog nyob rau hauv lub sijhawm off- lub sijhawm siab tshaj txhua hnub.

Lub ntiaj teb tau txais lub zog loj ntawm lub hnub. Qhov no yog qhov sib npaug ntawm 173 trillion watts (1 trillion=1,000,000,000,000) ntaus lub ntiaj teb txhua thib ob. Cov kev cov nyom thiab lub cib fim rau cov engineers muaj xws li nrhiav txoj hauv kev los siv ntau hom los ntes lub zog loj ntawm lub hnub.