Step 1: Read the question.
We must find the process that does NOT use dihydrogen gas ($\text{H}_2$) as an ingredient. The other three all consume $\text{H}_2$.
Step 2: Check making vanaspati ghee.
Liquid vegetable oils are hardened by adding $\text{H}_2$ over a nickel catalyst. This clearly uses $\text{H}_2$. So it is not the answer.
Step 3: Check making HCl.
Hydrogen gas burns with chlorine gas to form HCl. This uses $\text{H}_2$.
\[ \text{H}_2 + \text{Cl}_2 \rightarrow 2\text{HCl} \]
So it is not the answer.
Step 4: Check making metal hydrides.
Reactive metals combine with $\text{H}_2$ to give hydrides, like $2\text{Na} + \text{H}_2 \rightarrow 2\text{NaH}$. This uses $\text{H}_2$, so it is not the answer.
Step 5: Check gasification of coal.
Here coal reacts with steam to actually make $\text{H}_2$ (plus CO). So this process produces hydrogen, it does not use it.
\[ \text{C} + \text{H}_2\text{O} \rightarrow \text{CO} + \text{H}_2 \]
Step 6: Pick the answer.
The process that does not use $\text{H}_2$ is gasification of coal, which is option 1.
\[ \boxed{\text{Gasification of coal}} \]