Question

How can the production of dihydrogen, obtained from 'coal gastification', be increased?

Answer 1

Dihydrogen is produced by coal gastification method as:
$C_{\left(s\right)}+H_2{O}_{\left(g\right)}\stackrel{1270K}{\to }C{O}_{\left(g\right)}+H_{2\left(g\right)}$
The yield of dihydrogen (obtained from coal gastification) can be increased by reacting carbon monoxide (formed during the reaction) with steam in the presence of iron chromate as a catalyst.
$C{O}_{\left(g\right)}+H_2{O}_{\left(g\right)}\underset{Catalyst}{\overset{673K}{\to }}C{O}_{2\left(g\right)}+H_{2\left(g\right)}$
This reaction is called the water - gas shift reaction. Carbon dioxide is removed by scrubbing it with a solution of sodium arsenite.