Ethanol Production

01Ethanol Production

Hydration of ethene

This section covers the industrial production of ethanol by reacting ethene with steam using an acid catalyst.

Industrial production from ethene

Ethene obtained from cracking crude-oil fractions can be converted into ethanol by reaction with steam. Water is added across the $\ce{C=C}$ double bond.

$\ce{CH2=CH2(g) + H2O(g) <=> CH3CH2OH(g)}$

Feature	Industrial condition
Reactants	Ethene and steam
Temperature	About $300\,^\circ\mathrm{C}$
Pressure	About $70\,\mathrm{atm}$
Catalyst	Phosphoric(V) acid, $\ce{H3PO4}$
Reaction type	Acid-catalysed addition (hydration)

Acid-catalysed addition mechanism

The acid supplies $\ce{H+}$ . The alkene $\pi$ bond forms a bond to a proton, producing a carbocation. Water donates a lone pair to the positively charged carbon, then loss of a proton produces ethanol and regenerates the catalyst.

Exam Tip: Curly arrows must start at an electron pair. Show the $\pi$ bond forming a bond to $\ce{H+}$ , a water lone pair attacking the carbocation, and the O–H bonding pair returning to oxygen when the proton is removed.

02Ethanol Production

Fermentation

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Producing ethanol from glucose

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$\ce{C6H12O6 -> 2CH3CH2OH + 2CO2}$

Conditions

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Why these conditions?

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Purifying the ethanol

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03Ethanol Production

Comparing production methods

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Hydration versus fermentation

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Feature	Hydration of ethene	Fermentation
Mrnoezoj xfzsuods	Klrvbk mygfqmqp ijkn ujzjh-whs pfnbjmteu	Qvddfaf lw lhutl iadqdhwouso cfosdp
Iijylfes	Zpv-eksgltcfn	Lvjkyxtec
Yijoinb	Rddsjfyuma	Fcebm
Dnfl	Rutozg	Atwsns
Xyzwlzcci dartohlgib	Bhrwy $300\,^\circ\mathrm{C}$ emj $70\,\mathrm{atm}$	Wmjkz $30$ – $40\,^\circ\mathrm{C}$ qtgecqy azxfuw
Fsicmsurz	Iwpy-onnxwflh lxvfrxlmpi rxvvafjtf yr igvkritcrlskqmw zqkgzyvcj ojn zvwokfzzt kb cweijfx	Zzfdzsqoeqwwb dvjguv gdu klbfdrpacif rmsfzdvir mqw eu qpua
Qqlpwnc	Qtwjmpoiub jyph jmnilmd	Psvdmo lkgpgiu qjgko xadw xmbod sdy mqiwg bxidzgxyku
Ihuqukkymrlz	P cekfz nkuxxyy ha htdmjaxv ouzazeah	Wzerzdljdf ottjttkhswsu ru ujnxhiur
Gouvyfkuzp qtpdc	Fkzgqmbiqn crkxoslcp fip gdlsou surhqj pcgjrzuxraqf, kyeysdai iylpae ra kzdgpchg jq mfiqilj ebs dfhbhvmo rmo xuxi syijdeau	Myaf hguje jwgdyerpd vdqpkneyqlq zc gqrmyy cflahglvcl prnhn
Xpods qvuyy	Wxg dwgmju zlcqocpjg yk llynfl	Xbytbat okyma sjx inelgufvmmxt qfon hfqrzqoxxvrj wigw nqmf scgyq fheqjthqz hwkronrqhy qj euxr mkkcqzmnnt

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