Maitiro Ekuita Maitiro eHaber Bosch
Maitiro eHaber-Bosch ndeimwe yezvakawanikwa zvakakosha munhoroondo yemakemikari emaindasitiri nekuti anobvumira vanhu kugadzira ammonia (NH₃) pamwero mukuru kubva kumagasi maviri anowanikwa zvakasikwa: nitrogen (N₂) kubva mumhepo uye hydrogen (H₂), iyo inowanzo kuwanikwa kubva mugasi rechisikigo kana zvimwe zvinhu. Ammonia inobva yava chinhu chikuru chekugadzira nitrogen fertilizer dzakadai seurea neammonium nitrate, izvo zvinoita basa guru mukuwedzera kugadzirwa kwekurima pasi rose. Pasina maitiro aya, kuwanikwa kwechikafu pasi rose kungangove kushoma.
Nhoroondo: sei nitrogen yakaoma "kubata"?
Kunyangwe mhepo ine nitrogen inosvika 78%, gasi reN₂ rakagadzikana zvikuru nekuti maatomu ayo maviri enitrogen anobatanidzwa ne "strong triple bond" (N≡N). Chisungo ichi ndicho chinoita kuti nitrogen "irege" kuita chimwe chinhu. Zvirimwa zvinoda nitrogen kuti zvigadzire mapuroteni nema nucleic acids, asi hazvigone kushandisa N₂ zvakananga kubva mumhepo. Zvirimwa, nitrogen inogadziriswa nemabhakitiriya kana nemheni, asi mwero wemaitiro aya echisikigo hauna kukwana kusangana nezvinodiwa nekurima kwemazuva ano. Apa ndipo panopinda Haber-Bosch: kupa nzira "yekumanikidza" nitrogen kuti iite chimwe chinhu kuburikidza nemamiriro ekugadzira uye ma catalysts.
Maitiro makuru: kubva kunitrogen nehydrogen kuenda kuammonia
Iyo core reaction equation yemaitiro eHaber-Bosch ndeiyi:
N₂(g) + 3H₂(g) ⇌ 2NH₃(g) + kupisa
Kuita uku kunogona kudzoreka (kunogona kuenderera mberi munzira mbiri) uye exothermic (kunounza kupisa). Izvi zvinoreva kuti kuumbwa kweammonia kunofarirwa pakupisa kwakaderera zvichienderana nemutemo wekuenzana, asi pakupisa kwakaderera zvakanyanya, kuita uku kunoenderera zvishoma nezvishoma. Nokudaro, maitiro eindasitiri anofanira kuwana wirirano pakati pehuwandu hwekuita uye kubereka kwakaenzana.
Matanho makuru muHaber-Bosch process
Kazhinji, maitiro eindasitiri eHaber-Bosch anosanganisira matanho akati wandei: kupa zvinhu zvakagadzirwa (H₂ naN₂), kucheneswa, kudzvanywa, kuita kwekugadzira ne catalyst, kupatsanurwa kweammonia, uye kudzokororwa kwegasi risina kugadziriswa.
1. Manyuko uye kugadzirwa kwehydrogen (H₂)
Hydrogen yemaitiro eHaber-Bosch inowanzobva mukuvandudzwa kwegasi rechisikigo (methane, CH₄). Matanho acho anosanganisira:
– Steam methane reforming (SMR): methane inosanganiswa nemhepo inopisa pakupisa kwakanyanya kuti igadzire musanganiswa wegasi (syngas) une H₂, CO₂, uye CO₂.
– Kuchinja kwemvura negasi: CO inozogadziriswazve nemhepo inopfungaira kuti ibudise CO₂ uye H₂ iwedzere.
Pakupedzisira, CO₂ inoparadzaniswa uye hydrogen inocheneswa. Mune zvimwe zvirimwa, hydrogen inogonawo kuwanikwa kubva mumagetsi emvura, kunyanya uko magetsi anogona kushandiswazve, kunyange zvazvo izvi zvichiwanzodhura zvishoma pane gasi rechisikigo.
2. Kutora nitrogen (N₂) kubva mumhepo
Nitrogen inowanzo bviswa kuburikidza nekupatsanurwa kwemhepo uchishandisa ma cryogenic units (kutonhodza kusvika pakupisa kwakaderera) kana mamwe matekinoroji akadai se pressure swing adsorption (PSA). Chinangwa ndechekuwana nitrogen yakachena kwazvo, sezvo zvimwe zvinhu zvinosvibisa zvinogona kukuvadza catalyst uye kukanganisa reaction.
3. Kuchenesa gasi: kubvisa "chepfu" dzinokonzera kukuvadza
Zvinhu zvinoshandiswa muHaber-Bosch (zvinowanzova zvesimbi) zvinonzwa zvakanyanya kusanganiswa nezvinhu zvakaita sesarufa (S), kabhoni monoxide (CO), nezvimwe zvinhu zvakati wandei zvisina kuchena. Saka, gasi rekudya rinofanira kucheneswa:
– Mishonga yesarufa inobviswa uchishandisa zvinhu zvinosanganisa zvinonhuwira.
– CO₂ neCO₂ zvinobatwa kuburikidza nemakemikari (shift, methanation) kana kupatsanurwa kwemuviri/makemikari.
– Hunyoro (H₂O) hunoderedzwawo kuitira kuti husakanganise maitiro acho.
Kucheneswa uku kwakakosha zvikuru nekuti kushanda zvakanaka kwemiti uye hupenyu hwechikafu zvinoenderana zvakanyanya nekuchena kwegasi.
4. Kudzvanya: kuwedzera kumanikidzwa kwekuchinja kuenzana
Kuita uku kunoburitsa mamoles mashoma egasi (kubva pamamoles mana egasi kusvika pamamoles maviri egasi). Sekureva kwaLe Chatelier, kumanikidzwa kwakanyanya kuchachinja kuenzana kuenda kuchigadzirwa (NH₃). Nokudaro, musanganiswa weN₂ neH₂ unomanikidzwa kusvika pakumanikidzwa kwakanyanya, kazhinji mumazana emhepo mumabasa emazuva ano emaindasitiri (nhamba chaiyo inogona kusiyana zvichienderana nekugadzirwa kwechirimwa).
Zvisinei, kumanikidzwa kwakanyanya kunoreva simba guru rinodiwa pacompressor, saka chirimwa chinofanira kuwedzera pakati pehuwandu hweammonia nemutengo wesimba.
5. Muchina wekugadzira: basa remuchina wekugadzira uye tembiricha yekushanda
Mu reactor, musanganiswa weN₂ neH₂ unopfuudzwa pamusoro pe catalyst. Chinhu chinowanzo shandiswa paHaber-Bosch process iron (Fe) ine zvinhu zvinosimudzira zvakaita sepotassium oxide (K₂O), aluminium oxide (Al₂O₃), uye calcium oxide (CaO). Zvinhu zvinosimudzira zvinobatsira kuwedzera kushanda uye kugadzikana kwe catalyst.
Tembiricha yereaction inowanzo gadziriswa yakakwira zvakakwana kuti ive nechokwadi chekuti reaction rate yakakwana. Zvisinei, nekuti ammonia formation reaction i exothermic, tembiricha yakakwira zvakanyanya inoderedza equilibrium goho. Nokudaro, tembiricha inoiswa mukati mechikamu chekubvumirana chinobvumira reaction kuti ienderere mberi nekukurumidza uku ichiri kupa goho rakanaka.
Padanho remamorekuru, zvinhu zvinokonzeresa mashandiro zvinoshanda ne:
– Kupwanya ma bond eN≡N pamusoro pe catalyst (iri ndiro danho rakaoma zvikuru).
– Inosveta H₂ yoiputsa kuita maatomu eH.
– Inobatsira kuumbwa zvishoma nezvishoma kweN–H bonds kusvika NH₃ yaumbwa.
– Kuburitsa NH₃ kubva pamusoro pe catalyst kuitira kuti nzvimbo dziri kushanda dzigone kushandiswazve.
6. Kutonhodza uye kunyorovesa: kuparadzanisa ammonia kubva kugasi
Mushure mekubuda mu reactor, musanganiswa wegasi une NH₃ pamwe chete neN₂ neH₂ zvisina kugadziriswa. Musanganiswa uyu unobva watonhodzwa. Ammonia inonyungudika nyore nyore pasi pemamwe mamiriro ezvinhu, zvichiita kuti iparadzaniswe nekusanganiswa kuita ammonia yemvura.
Kupatsanurwa uku kwakavakirwa pa condensation kunobatsira zvikuru nekuti:
- Tsvaga chigadzirwa chikuru nemazvo
- Inokurudzira kuti mhinduro ienderere mberi (zvigadzirwa zvinotorwa, kuenzana kunosundirwa kuzvigadzirwa)
7. Kudzokorodza gasi: kunowedzera kushanda zvakanaka kwese
Haasi ese N₂ neH₂ anoshandurwa kuita NH₃ nekupfuura kamwe chete nereactor. Nokudaro, gasi rasara rinowanzo dzorerwa mureactor mushure mekuparadzaniswa neammonia. Kudzokorodza kunowedzera zvakanyanya mwero wekushandurwa kwemaitiro uye kunoita kuti kushandiswa kwezvinhu zvakabikwa kuve kwakanaka.
Panguva imwe chete, chikamu chidiki chegasi chinogona "kucheneswa" kudzivirira kuunganidzwa kwezvisina simba zvakaita seargon zvinotakurwa kubva mumhepo.
Zvinhu zvinopesvedzera mhedzisiro yemaitiro acho
Kune zvinhu zvitatu zvikuru zvinogara zvichikurukurwa muHaber-Bosch:
1. Kumanikidzwa: kumanikidzwa kwacho kwakanyanya, ndiko kukura kwemaitiro ekugadzira NH₃.
2. Kupisa: kupisa kwakaderera kunotsigira kuenzana, asi kupisa kwakakwirira kunowedzera kukurumidza kwekuita.
3. Chinosimudzira: chinokurumidza kusvika pakuenzana pasina kuchinja nzvimbo yekuenzana pachayo.
Maindasitiri anosarudza mamiriro ekushanda akakodzera anotarisa kuchengetedza, kuchengetedzeka, kushanda zvakanaka kwesimba, uye kugara kwenguva refu kwemidziyo.
Migumisiro nematambudziko emazuva ano
Maitiro eHaber-Bosch ave akakosha pakurima, asi anounzawo matambudziko ezvakatipoteredza. Kugadzira hydrogen kubva mugasi rechisikigo kunoburitsa CO₂ emissions. Saka, tsvakurudzo dzakawanda dzemazuva ano dzakanangana ne:
– Hydrogen “yakasvibira” inobva mumvura ine simba rinogona kushandiswazve
- Kutora nekuchengetedza kabhoni (CCS) mumiti yeammonia
- Kugadzira zvinhu zvitsva zvinoita kuti pave nekumanikidzwa kwakaderera kana tembiricha yakaderera
Izvi zvinovavarira kuchengetedza mabhenefiti makuru eammonia—kunyanya sefetereza—ukuwo ichideredza simba rayo recarbon.
Mhedziso
Maitiro eHaber-Bosch matanho akatevedzana eindasitiri akagadzirirwa kukunda kugadzikana kwenitrogen mumhepo uye kugadzira ammonia yakawanda. Chaizvoizvo inyaya yeN₂ neH₂ inotungamirirwa ne catalyst, yakagadziriswa kuburikidza nekumanikidzwa kwakanyanya, tembiricha dzakakanganisika, kucheneswa kwegasi, uye sisitimu yekuparadzanisa nekudzokorodza. Mugumisiro wacho kugadzirwa kweammonia, musimboti wefetereza yemazuva ano uye hwaro hwakakosha hwekuchengetedzeka kwechikafu pasi rose. Dambudziko guru remangwana remaitiro aya nderekuita kuti ive isingakuvadzi nharaunda kuburikidza ne hydrogen sources shoma uye kuwedzera kushanda zvakanaka kwesimba.
