Yuav kom tau acetylene los ntawm methane, nws yog ib qho tsim nyog yuav tsum tau ua cov tshuaj tiv thaiv dehydrogenation. Ua ntej yuav mus rau qhov kev txiav txim siab, cia peb txheeb xyuas qee yam ntawm hydrocarbon.
Acetylene yam ntxwv
Nov yog cov tshuaj gaseous, uas yog thawj tus neeg sawv cev ntawm cov chav kawm ntawm unsaturated hydrocarbons (alkynes). Nws yog sib dua li huab cua thiab tsis zoo soluble hauv dej. Cov mis mos molecular C2H2, ntau rau tag nrho cov chav SpN2n-2. Acetylene yog suav tias yog ib qho tshuaj nquag thiab tawg heev. Txhawm rau kom tsis txhob muaj xwm txheej kub ntxhov, nws tau muab khaws cia rau hauv cov thawv ntim hlau uas muaj charcoal ntxiv rau nws.
Production los ntawm alkanes
Acetylene tau los ntawm kev decomposition ntawm methane. Cov tshuaj tiv thaiv no yog ua los ntawm kev siv lub catalyst thiab tshwm sim ntawm qhov kub siab. Cov khoom pib yog thawj tus neeg sawv cev ntawm cov chav kawm ntawm paraffins. Dehydrogenation ua hydrogen ntxiv rau acetylene.
Teb cov lus nug ntawm yuav ua li cas kom tau acetylene los ntawm methane, qhov sib npaug ntawm cov tshuaj tiv thaiv tuaj yeem sawv cev li:
2CH4=C2H2+3H2
Carbide method
Nws tuaj yeem tau txais acetylene los ntawm methane lossis raws lipib cov khoom siv calcium carbide. Cov txheej txheem ua haujlwm raws li qhov qub. Thaum calcium carbide cuam tshuam nrog dej, tsis tsuas yog acetylene tsim, tab sis kuj calcium hydroxide (slaked txiv qaub). Cov cim qhia ntawm cov txheej txheem tshuaj yuav yog roj evolution (hissing), nrog rau kev hloov xim ntawm cov tshuaj thaum ntxiv phenolphthalein rau cov xim raspberry.
Thaum cov txheej txheem carbide uas muaj ntau yam impurities yog siv los ua cov khoom pib, cov ntxhiab tsw tsw qab tau pom thaum muaj kev cuam tshuam. Nws tau piav qhia los ntawm qhov muaj nyob hauv cov khoom siv tshuaj tiv thaiv ntawm cov tshuaj lom gaseous xws li phosphine, hydrogen sulfide.
Kev tawg ntawm cov khoom siv roj av
Tam sim no, nws tuaj yeem tau txais acetylene tsis yog los ntawm methane xwb. Txoj kev lag luam tseem ceeb rau kev tsim cov neeg sawv cev ntawm alkynes yog qhov tawg (splitting) ntawm hydrocarbons. Yog tias acetylene tau los ntawm methane, cov nqi hluav taws xob yuav tsawg. Ntxiv rau cov khoom siv pheej yig thiab siv tau, cov cuab yeej no nyiam cov neeg tsim khoom ntawm cov khoom siv hydrocarbon los ntawm kev yooj yim ntawm cov cuab yeej siv thev naus laus zis siv hauv cov txheej txheem ntawm methane dehydrogenation.
Muaj ob txoj hauv kev rau cov txheej txheem tshuaj. Thawj txoj kev yog raws li kev hla methane los ntawm electrodes rhuab mus rau 1600 degrees Celsius. Cov cuab yeej siv nrog kev ua kom txias txias ntawm cov khoom tshwm sim. Qhov thib ob kev xaiv rau dehydrogenation ntawm methane los tsim acetylene koom nrog kev siv lub zog uas yog generated thaum lub sij hawm ib nrab combustion ntawm no alkyne.
Lub tog raj kheej uas muaj acetylene tsis tuaj yeem nruab nrog cov khoom siv tooj liab, vim bronze muaj tooj liab. Kev sib cuam tshuam ntawm cov hlau no nrog acetylene yog nrog los ntawm kev tsim cov ntsev tawg.
Zoo kawg
Acetylene tam sim no siv nyob rau hauv ntau qhov chaw lag luam. Nws yog ib qho tseem ceeb raw khoom rau kev sib txuas ntawm ethanol, plastics, rubbers, thiab acetic acid. Tus neeg sawv cev ntawm cov chav kawm ntawm alkynes yog nyob rau hauv kev thov thaum txiav thiab vuam hlau, raws li lub teeb ci nyob rau hauv ib tug neeg lub teeb.
Rau lub hauv paus ntawm acetylene, kev sib xyaw ntawm cov khoom tawg siv los ua detonators yog ua tiav. Nyob rau hauv oxidation cov tshuaj tiv thaiv ntawm no alkyne nyob rau hauv atmospheric oxygen, ib tug muaj zog nplaim taws pom. Methane tsis muaj nqi tsawg hauv kev lag luam tshuaj. Ntxiv nrog rau nws siv los ua cov khoom pib rau kev tsim cov acetylene, nws tau noj ntau ntau raws li cov khoom siv hluav taws xob hauv kev lag luam roj. Thaum nws kub hnyiab, cov cua kub tseem ceeb tso tawm.
