Industrial ethanol is manufactured worldwide using two distinct chemical pathways:
Name the catalyst required for each industrial method.
Two industrial chemical consortia produce ethanol for distinct commercial markets. The table below outlines their operational parameters:
| Enterprise A | Enterprise B | |
|---|---|---|
| Location | Tropical region with extensive sugar beet and maize cultivation | Integrated chemical corridor with direct pipeline access to a steam cracker |
| Primary Use of Ethanol | Bioethanol fuel additive for local automotive market | High-grade precursor for ester solvents used in pharmaceutical synthesis |
Explain which manufacturing method each enterprise is more likely to adopt.
Alkenes required for the production of addition polymers are typically sourced from the thermal cracking of long-chain alkanes found in crude oil fractions.
One such polymer is poly(but-1-ene), synthesised from the monomer but-1-ene. Complete the equation below to show the structure of the polymer formed:
nHH∣∣C=C∣∣HCH2CH3⟶… \text{n} \begin{array}{cc} \text{H} & \text{H} \\ | & | \\ \text{C} & \hspace{-0.5em}=\text{C} \\ | & | \\ \text{H} & \text{CH}_2\text{CH}_3 \end{array} \longrightarrow \dots nH∣C∣HH∣=C∣CH2CH3⟶…A heavy liquid alkane fraction contains hexadecane, C16H34\text{C}_{16}\text{H}_{34}C16H34. Complete the equation to show the thermal cracking of one molecule of C16H34\text{C}_{16}\text{H}_{34}C16H34 to form two molecules of ethene and one molecule of another hydrocarbon:
C16H34→2C2H4+… \text{C}_{16}\text{H}_{34} \rightarrow 2\text{C}_2\text{H}_4 + \dots C16H34→2C2H4+…Explain why future chemical production may need to transition towards obtaining alkenes (such as ethene) from plant-derived bioethanol rather than continuing to rely on crude oil fractions.
