Commercial hydrogen is obtained from

Options

A. Coal gas
B. Water gas
C. Air
D. Producer gas

Answer

**Step-by-Step Solution:**

1. **Understanding the Question:**
The question asks about the source from which commercial hydrogen is obtained. We have four options: coal gas, water gas, air, and producer gas.

2. **Identifying the Relevant Process:**
Commercial hydrogen is primarily produced through a process known as the Bosch process, which is also referred to as the water gas reaction.

3. **Describing the Bosch Process:**
- The Bosch process involves two main steps:
- **Step 1: Coal Gasification**
- In this step, carbon (from coal) is reacted with steam at high temperatures (around 1000°C) to produce water gas, which is a mixture of hydrogen and carbon monoxide.
- **Step 2: Water Gas Shift Reaction**
- The water gas produced in the first step is then reacted with steam again at a lower temperature (around 400°C) in the presence of catalysts (iron oxide and chromium oxide). This reaction converts carbon monoxide and steam into carbon dioxide and additional hydrogen gas.

4. **Separation of Hydrogen:**
- After the water gas shift reaction, hydrogen can be easily separated from carbon dioxide, allowing for the collection of commercial hydrogen.

5. **Evaluating the Options:**
- Coal gas: Not primarily used for commercial hydrogen production.
- Water gas: Yes, this is the correct answer as it is involved in the Bosch process.
- Air: Not a source for commercial hydrogen.
- Producer gas: Not primarily used for commercial hydrogen production.

6. **Conclusion:**
The correct answer is **water gas**, as it is the source from which commercial hydrogen is obtained through the Bosch process.

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