Question

Write the reaction to prepare hydrogen using Bosch process

Answer 1

Various steps are involved in Bosch process. It is given as follows:

• Production of water gas: The mixture of carbon monoxide (CO) and hydrogen (H₂) is obtained by passing superheated steam over red hot coke or coal at${1000}^0\mathrm{C}$. This process of formation of water gas from coke or coal is called coal gasification.

$$\begin{gathered} \mathrm{C}\left(\mathrm{s}\right)+{\mathrm{H}}_2\mathrm{O}\left(\mathrm{g}\right)\stackrel{{1000}^0\mathrm{C}}{\to }\underbrace{\mathrm{CO}\left(\mathrm{g}\right)+{\mathrm{H}}_2\left(\mathrm{g}\right)} \\ \mathrm{Carbon}\mathrm{Water}\mathrm{water}\mathrm{gas} \end{gathered}$$

• Reduction of steam by water gas: To remove CO and to increase the production of hydrogen gas from water gas CO is oxidized to CO₂ by mixing it with more steam at 673K in the presence of iron chromate and little chromium oxide as catalyst. The reaction in which carbon monoxide of water gas reacts with steam to give carbon dioxide and more hydrogen gas is called the water gas shift reaction.

.$$\begin{gathered} \underbrace{\mathrm{CO}\left(\mathrm{g}\right)+{\mathrm{H}}_2\left(\mathrm{g}\right)}+{\mathrm{H}}_2\mathrm{O}\left(\mathrm{g}\right)\underset{{\mathrm{FeCrO}}_4}{\overset{{450}^0\mathrm{C}}{\to }}{\mathrm{CO}}_{2\left(\mathrm{g}\right)}+2{\mathrm{H}}_2\left(\mathrm{g}\right) \\ \mathrm{Water}\mathrm{gas}\mathrm{steam}\mathrm{carbon}\mathrm{dioxide}\mathrm{Hydrogen} \end{gathered}$$