What is a disadvantage of the industrial method for producing ethanol?

• A. Crude oil is non-renewable and a large amount of energy is used
• B. It uses renewable energy and requires little energy
• C. It produces a clone of ethanol only
• D. It generates no emissions

Answer: (A)

Industrial ethanol production by hydration of ethene relies on a petrochemical route. Ethene is derived from crude oil, a non-renewable resource, and the process requires high temperature and pressure with a catalyst, meaning a large energy input. This combination makes the method energy-intensive and less sustainable compared with bio-based alternatives. There are also emissions associated with the energy use and the refinery process. So the main drawback is dependence on non-renewable crude oil and the substantial energy demand. The other statements don’t fit because they imply renewable feedstock, low energy use, only producing ethanol without by-products, or zero emissions, which isn’t true for this industrial route.