Which of the following is not used for industrial prepa-ration of methanol ?

Options

A. `CH_(4)`
B. CO
C. `H_(2)`
D. Wood

Answer

To determine which of the following options is not used for the industrial preparation of methanol, we will analyze each option one by one:

1. **Methane (CH₄)**:
- Methane can be converted to methanol through a reaction with oxygen. The reaction occurs in the presence of a catalyst (copper) at a temperature of about 573 K.
- The balanced equation for this reaction is:
\[ 2 \text{CH}_4 + \text{O}_2 \rightarrow 2 \text{CH}_3\text{OH} \]
- Since methane is used to prepare methanol, it is not the answer to the question.

2. **Carbon Monoxide (CO)**:
- Carbon monoxide can react with hydrogen to produce methanol. This reaction typically takes place at high temperature and pressure, using zinc oxide and chromium oxide as catalysts.
- The reaction can be represented as:
\[ \text{CO} + 2 \text{H}_2 \rightarrow \text{CH}_3\text{OH} \]
- This method is one of the major industrial processes for methanol production, so carbon monoxide is also not the answer.

3. **Hydrogen (H₂)**:
- Hydrogen alone does not react to form methanol. There is no direct method to produce methanol solely from hydrogen without the presence of carbon monoxide or other carbon sources.
- Therefore, hydrogen is not used for the industrial preparation of methanol, making it the correct answer to the question.

4. **Wood**:
- Wood can be converted to methanol through a process that involves pyrolysis, where wood is burned in the presence of oxygen at high temperatures to produce pyrolysis oil, which can then be further processed to yield methanol.
- Thus, wood can also be used to prepare methanol, so it is not the answer.

**Final Answer**: Hydrogen (H₂) is not used for the industrial preparation of methanol.