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

Explanation

The process of producing a mixture of carbon monoxide and hydrogen from coal is calld coal gasification. This mixture is also called synthesis gas or syn gas.
`C(s)+H_(2)O(g) overset(1270K)to CO_(g)+H_(2)(g)`
The production of hydrogen can be increased by reacting carbon monoxide of syn gas with steam in the presence of iron chromate as catalyst at 673 K.
`CO(g) + underset("stream")(H_2 O(g)) underset(673K)overset(FeCrO_4)to CO_2 (g) + H_2 (g)`
The `CO_2` thus produced is removed by scrubling with a solution of sodium arsenite.