Kev tsim cov nitric acid hauv kev lag luam: thev naus laus zis, theem, nta

2024 Tus sau: Howard Calhoun | [email protected]. Kawg hloov kho: 2023-12-17 10:28

Nitric acid yog ib qho ntawm cov xav tau tshaj plaws ntawm cov khoom siv raw khoom. Nws cov khoom tuaj yeem ua tau los ntawm ntau txoj hauv kev - nyob ntawm ntau yam uas cov kua qaub yuav tsum tau muab rau cov neeg siv khoom. Dab tsi yog qhov tseem ceeb ntawm cov thev naus laus zis? Lawv piv li cas rau hom nitric acid uas tsim nyob rau hauv lub Hoobkas?

Kev lag luam tsim cov nitric acid: keeb kwm ntawm kev txhim kho thev naus laus zis

Ua ntej ntawm tag nrho, nws yuav muaj txiaj ntsig los kawm txog keeb kwm qhov tseeb txog kev tsim cov nitric acid li cas hauv tebchaws Russia. Hauv kev lag luam hauv tsev, kev tso tawm ntawm cov tshuaj no, raws li cov ntaub ntawv muaj, tau pib los ntawm Peter I. Tom qab ntawd, MV Lomonosov tau npaj ib txoj hauv kev rau kev tsim cov nitric acid los ntawm s altpeter - cov khoom no tau suav tias yog cov khoom siv tseem ceeb rau kev tsim khoom. ntawm cov khoom nyob rau hauv nqe lus nug txog thaum pib ntawm lub xyoo pua 20th.

Nrog rau ntsev, kev tsim cov nitric acid hauv kev lag luam tau ua los ntawm kev siv sulfuric acid. Ob yam tshuaj nyob rau hauv kev txiav txim siab, cuam tshuam nrog ib leeg, tsim nitric acid thiab sodium sulfur oxide. Qhov zoo ntawm qhov noTxoj kev yog lub peev xwm kom tau txais nitric acid ntawm ib tug concentration ntawm txog 96-98% (nyob rau hauv kev siv ntawm raw cov ntaub ntawv uas yuav tsum tau zoo).

Cov thev naus laus zis sib xws tau ua kom zoo dua qub - hauv kev pom zoo ntawm kev ua kom cov ntaub ntawv raw thiab ua kom cov khoom siv ntau dua. Tab sis maj mam muab txoj hauv kev rau lub tswv yim tias kev tsim cov nitric acid tau ua los ntawm kev sib cuag oxidation ntawm ammonia.

Tsis tas li, ib txoj kev tau tsim nyob rau hauv uas nitric oxide, tau los ntawm arc oxidation ntawm cov pa sib xws los ntawm cov cua, tau siv los ua cov khoom siv tseem ceeb rau kev tsim cov kua qaub. Muaj kev pom dav dav tias thawj txoj hauv kev yog tus nqi ntau dua.

Nrog rau kev txhim kho cov txheej txheem thev naus laus zis rau kev tsim cov nitric acid, ib txoj hauv kev tau tsim raws li qhov kev xaiv zoo tshaj plaws rau kev tsim cov khoom siv sib xws yog kev siv cov khoom lag luam hauv kev ua haujlwm siab. Lwm txoj hauv kev rau nws yog kev tsim cov kua qaub ntawm atmospheric siab, uas yog suav hais tias tsis tshua muaj txiaj ntsig los ntawm qhov kev xav ntawm kev lag luam.

Kev tso tawm ntawm ib yam khoom ntawm qhov qub lossis siab siab cuam tshuam nrog kev tsim cov nitric acid los ntawm ammonia. Kuj tseem muaj kev sib xyaw ua ke uas sib xyaw ua ke ntawm qhov zoo ntawm ob qho tib si. Cov yam ntxwv ntawm kev tsim cov nitric acid los ntawm kev sib xyaw ua ke yog, ua ntej, nyob rau hauv oxidation ntawm ammonia ntawm atmospheric siab, thiab kev siv ntawm nws nqus - ntawmnce.

Ammonia tam sim no suav tias yog cov khoom siv tseem ceeb rau kev tso tawm cov khoom hauv nqe lus nug, nrog rau dej thiab huab cua. Cia peb kawm txog qhov tshwj xeeb ntawm lawv siv hauv kev tsim cov kua qaub kom ntxaws ntxiv.

Nitric acid feedstock

Yog li, cov khoom siv tseem ceeb siv hauv kev tsim cov tshuaj hauv nqe lus nug yog ammonia, cua, thiab dej.

Qhov no yuav tsum tau siv cov ammonia purified. Ua li no, nws yog purified nyob rau hauv tshwj xeeb evaporation thiab distillation khoom nyob rau hauv lub moj khaum ntawm ntau lawm cycles. Ib yam li ntawd, huab cua huv yuav tsum tau siv thaum tso tawm nitric acid. Nws kuj tau lim siv cov cuab yeej tshwj xeeb. Nyob rau hauv lem, cov dej siv nyob rau hauv zus tau tej cov nitric acid yog purified los ntawm impurities thiab ntsev. Feem ntau, cov condensate ntshiab yuav tsum tau siv kom tau cov khoom hauv nqe lus nug.

Cia peb kawm seb hom tshuaj twg hauv nqe lus nug tuaj yeem nthuav tawm, nrog rau seb txhua hom nitric acid tsim li cas.

Ntau yam ntawm nitric acid thiab cov theem tseem ceeb ntawm nws tso tawm

Muaj 2 hom nitric acid tsim nyob rau hauv niaj hnub kev lag luam nroj tsuag - diluted thiab concentrated. Kev tsim cov dilute nitric acid yog ua nyob rau hauv 3 theem tseem ceeb:

• hloov pauv ntawm ammonia (nws cov khoom kawg yog nitric oxide);
• ua nitrogen dioxide;
• ua raws li kev nqus ntawm nitrogen oxides ntawmsiv dej.

Kev tsim cov dilute nitric acid yog dav nyob rau hauv niaj hnub kev lag luam kev lag luam raws li lub npe hu ua AK-72 tswvyim. Tab sis, tau kawg, muaj lwm yam thev naus laus zis rau kev tso tawm cov tshuaj no.

Nyob rau hauv lem, kev tsim cov concentrated nitric acid tuaj yeem ua tiav los ntawm kev nce qib ntawm cov khoom sib xws hauv daim ntawv dilute lossis los ntawm kev sib txuas ncaj qha. Thawj txoj kev, raws li txoj cai, ua rau nws muaj peev xwm kom tau txais cov kua qaub ntawm qhov concentration ntawm 68%, uas tej zaum yuav tsis txaus rau kev siv cov tshuaj hauv cov lus nug hauv ntau qhov chaw. Yog li ntawd, cov txheej txheem ntawm kev sib txuas ncaj qha kuj tseem muaj, uas ua rau nws muaj peev xwm tau txais cov khoom hauv qhov concentration ntawm 97-98%.

Cia peb saib seb yuav ua li cas nitric acid yog tsim nyob rau hauv ib daim ntawv los yog lwm yam. Saum toj no, peb tau sau tseg tias kev tso tawm cov tshuaj diluted tuaj yeem ua tau raws li AK-72 tswvyim. Cia peb kawm nws qhov tshwj xeeb ua ntej.

Kev tsim cov kua qaub dilute siv AK-72 thev naus laus zis

Cov txheej txheem txiav txim siab, dhau los ntawm kev tsim cov nitric acid, suav nrog kev siv lub voj voog kaw, nrog rau:

• ammonia conversion;
• cua txias txuam gases ntawm qhov siab ntawm 0.42-0.47 MPa:
• ua haujlwm nqus oxides nyob rau hauv siab ntawm qhov kev txiav txim ntawm 1.1-1.26 MPa.

Cov khoom kawg ntawm AK-72 cov tswv yim yog nitric acid ntawm qhov concentration ntawm 60%. Kev tsim cov nitric acid nyob rau hauvthev naus laus zis raws li kev txiav txim siab tau ua nyob rau hauv lub moj khaum ntawm cov theem xws li:

• kom ntseeg tau tias huab cua los ntawm huab cua mus rau hauv chav tsev thiab nws ntxuav;
• compressing cua, cais nws mus rau hauv kev yees;
• evaporation ntawm ammonia, purification ntawm cov roj coj los ntawm cov roj thiab lwm yam impurities, nrog rau nws cov cua kub tom qab;
• sib tov ntawm purified ammonia thiab cua, tom qab purification ntawm no sib tov thiab nws hloov mus rau lub catalyst;
• tau txais cov pa roj nitrous thiab lawv cov cua txias;
• condensate sau nrog nitric acid;
• concentration thiab nqus ntawm nitric acid;
• txias thiab ntxuav cov khoom uas tshwm sim.

Tiav kua qaub xa mus rau qhov chaw cia lossis cov neeg siv khoom.

Nrog rau cov thev naus laus zis hauv kev txiav txim siab rau kev tsim cov nitric acid - AK-72, lwm lub tswv yim nrov rau kev tso tawm cov khoom siv sib xws, uas suav nrog kev ua haujlwm ntawm kev lag luam kev lag luam ntawm qhov siab ntawm li 0.7 MPa.. Xav txog nws cov yam ntxwv.

Cov khoom tso tawm thev naus laus zis hauv siab 0.7 MPa: nuances

Cov thev naus laus zis hauv nqe lus nug tsim cov nitric acid uas tsis muaj zog los ua lwm txoj hauv kev rau lub tswv yim AK-72. Nws suav nrog kev siv cov theem hauv qab no ntawm kev tso tawm cov khoom hauv nqe lus nug.

Ua ntej tshaj plaws, ib yam li yav dhau los thev naus laus zis, huab cua hauv huab cua raug ntxuav. Rau lub hom phiaj no, raws li txoj cai, siv ob-theem lim. Tsis tas li ntawd, cov huab cua uas tau muab ntxuav yog compressedlos ntawm kev siv cua compressor - txog li 0.35 MPa. Nyob rau hauv cov ntaub ntawv no, huab cua yog rhuab - mus txog rau ib tug kub ntawm txog 175 degrees, thiab nws yuav tsum tau txias. Tom qab qhov teeb meem no tau daws, nws mus rau thaj tsam ntawm qhov compression ntxiv, uas nws lub siab nce mus txog kwv yees li 0.716 MPa. Qhov tshwm sim ntawm huab cua ntws, nyob rau hauv lem, yog rhuab mus rau ib tug high kub - txog 270 degrees los ntawm qhov kev txiav txim ntawm nitrous gases. Nws yog ces tov nrog ammonia nyob rau hauv ib tug tshwj xeeb cheeb tsam ntawm lub industrial unit. Cov khoom sib xws yog qhib thaum cov kua qaub tso tawm thawj zaug hauv lub xeev gaseous, uas yog tsim los ntawm evaporation ntawm cov kua. Tsis tas li ntawd, ammonia yuav tsum tau purified. Tom qab kev npaj, cov roj yog rhuab thiab pub rau hauv lub tov khoom ib txhij nrog cua. Qhov sib tov no kuj tau lim thiab, tom qab ntxuav, yog pub rau kev hloov pauv ntawm ammonia. Cov txheej txheem sib thooj yog ua los ntawm kev siv platinum thiab rhodium alloy meshes ntawm qhov kub thiab txias - txog 900 degrees. Tus nqi hloov pauv yog kwv yees li 96%.

Kev tsim cov nitric acid tsis muaj zog raws li thev naus laus zis hauv kev txiav txim siab suav nrog kev tsim cov roj nitrous. Lawv raug coj mus rau ib qho chaw tshwj xeeb ntawm chav tsev, uas lawv tau txias. Vim li no, cov dej huv huv evaporates thiab cov tsos ntawm chav nrog kev kub siab. Ua tiav los ntawm thaj chaw tsim nyog ntawm chav tsev, cov pa roj nitrous txav mus rau hauv oxidizer. Nws yuav tsum tau muab sau tseg tias lawv oxidation ib feem tshwm sim nyob rau yav dhau losacid ntau lawm. Tab sis nyob rau hauv lub oxidizer nws yuav txawm khaus. Nyob rau hauv cov ntaub ntawv no, nitrous gases yog rhuab mus rau ib tug kub ntawm txog 335 degrees. Tom qab ntawd, lawv tau txias rau hauv lub tshuab hluav taws xob tshwj xeeb, thiab tom qab ntawd lawv raug xa mus rau lub condenser.

Tom qab ntawd, nitric acid yog tsim nyob rau hauv ib tug tsis muaj zog concentration. Nws yog ib qho tsim nyog los cais cov roj nitrous ntxiv los ntawm nws - lub tshuab cais yog siv rau qhov no. Los ntawm nws, nitric acid yog pub rau hauv qhov chaw nqus ntawm chav tsev. Cov kua qaub tom qab ntws mus rau thaj chaw ntawm cov cuab yeej hauv qab no. Nyob rau tib lub sijhawm, nws cuam tshuam nrog nitrogen oxides, vim tias nws cov concentration nce. Ntawm cov zis, nws yog hais txog 55-58%. Nws feem ntau muaj cov yaj oxides uas yuav tsum tau muab tshem tawm: rau qhov no, cov khoom raug xa mus rau qhov chaw huv ntawm chav tsev. Nrog kev pab los ntawm cua sov, oxides yog muab rho tawm los ntawm cov kua qaub. Cov khoom tiav yog muab tso rau hauv lub tsev rau khoom lossis xa mus rau tus neeg siv khoom.

Kev tsim cov concentrated acid: direct synthesis

Tau txiav txim siab yuav ua li cas cov tshuaj dilute nitric acid tau ua tiav, peb yuav kawm txog qhov tshwj xeeb ntawm kev tso tawm cov tshuaj muaj zog. Kev tsim cov kua qaub los ntawm kev sib txuas ncaj qha los ntawm cov khoom siv raw hauv daim ntawv ntawm nitrogen oxides yog cov thev naus laus zis zoo tshaj plaws siv nyob rau hauv kev lag luam ntawm qhov profile.

Lub ntsiab ntawm txoj kev no yog los txhawb cov tshuaj tiv thaiv ntawm cov khoom siv, dej, thiab oxygen nyob rau hauv lub siab ntawm li 5 MPa. Lub tshuab uas tsim cov nitric acid yog nqa tawmhom concentrated nyob rau hauv lub hauv paus ntawm ib tug dilute, muaj ib tug nuance: xyuas kom meej qhov kev hloov ntawm nitrogen dioxide mus rau hauv ib tug kua daim ntawv yog ua tau nyob rau hauv lub siab thiab kub nyob ze rau atmospheric. Txawm li cas los xij, hauv qee qhov kev cuam tshuam, qhov concentration ntawm cov khoom sib xws tsis txaus los hloov nws mus rau lub xeev ua kua ntawm lub siab, thiab nws yuav tsum tau nce ntxiv.

Kev tsim cov concentrated acid raws li dilute acid

Nyob rau hauv cov ntaub ntawv no, nws yog assumed tias cov kua qaub yog concentrated los ntawm lub absorbent tshuaj - xws li sulfuric, phosphoric acid, ntau yam kev daws teeb meem ntawm nitrates. Cov kauj ruam tseem ceeb hauv kev tsim cov concentrated nitric acid raws li diluted sulfuric acid yog raws li hauv qab no.

Ua ntej, cov khoom siv raw tau muab faib ua 2 kwj: thawj zaug yog pub rau hauv cov evaporator, qhov thib ob - nkag mus rau qhov chaw txias ntawm chav tsev. Sulfuric acid yog pub rau thaj tsam ntawm lub cuab yeej saum toj ob dilute nitric acid kwj. Nyob rau hauv lem, chav yog nkag mus rau hauv lub qis ntawm chav tsev, uas heats lub sib tov siv, vim hais tias ntawm cov nitric acid evaporates los ntawm nws. Nws cov vapors nce lub cuab yeej, tom qab ntawd lawv raug tshem tawm mus rau lub tub yees. Nyob ntawd, kua qaub vapors condense - kom txog thaum nws cov concentration nce mus txog 98-99%.

Tib lub sijhawm, qee qhov ntawm nitrogen oxides tam sim no thaum lub sijhawm tsim khoom no tau nqus los ntawm cov kua qaub. Lawv yuav tsum tau muab rho tawm los ntawm cov khoom: feem ntau, nitric acid vapors yog siv rau lub hom phiaj no, uas yog xa mus rau lub condenser. Cov extracted nitrogen oxides, nrog rau cov kua qaub vapors uas tsis tsim ib tug condensate, raug xa mus rau lwm qhov chaw ntawm lub apparatus - rau nqus, qhov twg lawv kho nrog dej. Yog li ntawd, dilute acid yog tsim, uas yog rov pub rau condensation thiab txias. Cov khoom tiav raug xa mus rau lub tsev qiv ntawv lossis rau cov neeg siv khoom.

Ntawm cov ntsiab lus nrog sulfuric acid

Lub luag haujlwm tseem ceeb uas qhia txog kev tsim cov nitric acid hauv kev lag luam yog kev siv nws cov txiaj ntsig zoo thiab muaj txiaj ntsig zoo. Muaj ob peb txoj hauv kev los tsim ib lub tswv yim zoo rau kev daws nws. Nws yuav muaj txiaj ntsig los xav txog cov uas muaj ntau tshaj plaws.

Peb tau sau tseg saum toj no tias sulfuric acid tuaj yeem siv los mloog cov tshuaj hauv nqe lus nug. Muaj ib txoj hauv kev zoo los ua kom muaj txiaj ntsig ntawm nws txoj kev siv - kev nce ntxiv hauv cov concentration ntawm nitric acid los ntawm evaporation. Qhov zoo tshaj plaws, ua ntej kev kho mob nrog sulfuric acid, cov khoom sib xws yuav muaj qhov concentration ntawm 59-60%. Nws yuav tsum tau muab sau tseg tias nyob rau hauv kev xyaum no technology rau zus tau tej cov nitric acid yog yus muaj los ntawm ib tug tsawg theem ntawm ib puag ncig tus phooj ywg. Yog li, raws li lwm txoj hauv kev siv sulfuric acid, kev siv nitrates feem ntau. Cia peb kawm txog lawv qhov tshwj xeeb hauv kev nthuav dav ntxiv.

Kev sib xyaw nrog nitrates

Feem ntau, magnesium lossis zinc nitrates yog siv los daws cov teeb meem raws li kev txiav txim siab, uas qhia txog kev tsim cov nitric acid los ntawm ammonia. Ua ntej ntawm tag nrho cov, nws yog ib qho tseem ceeb tshaj ib puag ncig tus phooj ywg tshaj li txoj kevkoom nrog kev siv sulfuric acid. Tsis tas li ntawd, cov thev naus laus zis no ua kom zoo tshaj plaws ntawm nitric acid ua cov khoom kawg.

Tib lub sijhawm, nws muaj ntau qhov tsis txaus, uas ua rau pom qhov nyuaj ntawm nws daim ntawv thov dav. Ua ntej tshaj plaws, qhov no yog tus nqi siab ntawm cov txheej txheem ntau lawm. Tsis tas li ntawd, qhov kev siv tshuab no feem ntau suav nrog kev tsim cov khoom pov tseg, kev ua haujlwm uas tuaj yeem nyuaj.

Kev siv cov catalysts hauv kev tsim cov nitric acid

Nws yuav muaj txiaj ntsig zoo los txiav txim siab lwm yam tshuaj siv nrog rau cov khoom siv tseem ceeb rau kev tsim cov khoom lag luam hauv nqe lus nug hauv kev lag luam (feem ntau catalysts raug suav hais tias yog li ntawd) tsim cov nitric acid. Kev siv cov tshuaj nyob rau hauv nqe lus nug yog vim qhov xav tau los ua kom cov txiaj ntsig ntawm cov kua qaub ntau lawm, ua rau kom muaj zog ntawm nws cov khoom tsim tawm ntawm chav tsev.

Qhov kev xav tau tseem ceeb rau lub catalyst hauv kev tsim cov khoom hauv nqe lus nug yog kev xaiv ntawm kev ua. Ntawd yog, nws yuav tsum cuam tshuam rau cov tshuaj tiv thaiv tseem ceeb yam tsis muaj kev cuam tshuam rau sab txheej txheem. Feem ntau, cov catalysts yog siv los tsim cov kua qaub, uas muaj platinum.

Saum toj no, peb tau sau tseg tias thaum cov tshuaj tsis muaj zog muaj zog tso tawm ntawm qhov siab siab, cov catalysts raws li platinum thiab rhodium siv. Qee zaum, cov alloys nrog qhov sib ntxiv ntawm palladium kuj tau siv. Tab sis cov hlau tseem ceeb hauv lawv yogplatinum, nws cov ntsiab lus feem ntau tsis tsawg dua 81%. Lub ntsiab ntawm cov catalyst nyob rau hauv cov ntaub ntawv no yog los txhawb txoj kev sai ntawm cov tshuaj tiv thaiv tseem ceeb. Raws li txoj cai, nws dhau mus rau sab nraud diffusion seem.

txheej txheem nyob ntawm qhov txwv ntawm cov pa oxygen diffusion txheeb ze rau qhov chaw catalyst. Qhov no feature ua rau ib tug ntau dua concentration ntawm ammonia, lub ntsiab raw khoom rau zus tau tej cov nitric acid, nyob rau saum npoo ntawm ib los yog tej zaum cov catalyst, thaum piv nrog rau cov concentration nyob rau hauv cov huab cua. Nws yog ib qho ua tau kom nce lub ntiajteb txawj nqus ntawm ntau yam kev tawm tsam uas tsis tiav oxidation thiab tsim cov nitrogen lossis nws cov oxide raug pom. Hauv qhov no, oxygen nyob ze ntawm qhov chaw yuav tsum muaj qhov txaus kom tshem tawm ammonia. Nyob rau hauv cov ntaub ntawv no, nws yuav ua tau kom tiav ib tug txaus oxidation.

Nws tuaj yeem raug sau tseg tias, nrog rau cov platinum catalysts, cov tshuaj sib xyaw ua ke kuj koom nrog hauv kev tsim cov nitric acid. Hauv particular, hlau-chromium. Lawv tuaj yeem txo cov nqi kev lag luam uas qhia txog kev tsim cov khoom hauv nqe lus nug.

Yog li, peb tau txiav txim siab cov txheej txheem ntawm kev tsim cov nitric acid, txheeb xyuas nws cov hom tseem ceeb. Yuav ua li cas muaj pes tsawg theem ntawm nitric acid ntau lawm yuav tsum tau siv nyob rau hauv nws cov hom, raws li zoo raws li lub tshwj xeeb technology rau kev tso tawm ntawm cov khoom siv. Nws yuav muaj txiaj ntsig tam sim no los txiav txim siab qhov teeb meem dab tsi ua rau muaj kev tsim khoom ntawm cov khoom no, uas yog xav tau hauv ntau qhov chaw ntawm kev lag luam.

Cov teeb meem tseem ceeb hauvnitric acid ntau lawm

Yog li, raws li peb twb paub lawm, kev tsim cov nitric acid los ntawm txoj kev sib cuag - ib qho ntawm feem ntau hauv kev lag luam niaj hnub no, suav nrog kev siv cov catalyst txhawm rau txhawm rau txhawm rau oxidation ntawm ammonia thiab nce cov txiaj ntsig ntawm cov khoom. Qhov teeb meem tseem ceeb hauv kev tsim cov khoom raws li kev txiav txim siab yog tus nqi siab ntawm cov khoom siv catalyst. Txawm li cas los xij, nws qhov kev xaiv tsis yog ib txwm ncav cuag tus nqi zoo. Tsis tas li ntawd, ib feem tseem ceeb ntawm platinum uas yog siv los ua lub hauv paus tseem ceeb rau cov catalyst tuaj yeem poob thaum lub sijhawm tsim khoom. Raws li qhov tshwm sim, dua, tus nqi-ua tau zoo ntawm cov khoom tsim tawm txo qis.

Ib qho teeb meem uas qhia txog kev tsim cov nitric acid yog ib puag ncig. Saum toj no, peb tau sau tseg tias sulfuric acid tuaj yeem siv nrog cov ntsiab lus ntawm cov khoom siv raw, thiab thaum dhau los ntawm lub voj voog ntau lawm, cov khoom tsis zoo raug tsim. Ib qho kev xaiv hauv qhov no yuav yog kev siv nitrates - tab sis qhov no, dua, qhia txog kev nce nqi ntawm kev lag luam. Txawm li cas los xij, ib puag ncig zoo rau cov tuam txhab niaj hnub niaj hnub no yog qhov tseem ceeb raws li qib ntawm cov txiaj ntsig ntau lawm.