Tomita [21, 22] has reported low temperature gasification of Yallourn coal catalysed by nickel. By the different way of prepared catalyst as usual like conventional impregnation methods, coal was mixed with an aqueous solution of hexamine nickel carbonate. This mixture gave a perfect homogeneous, catalyst bearing coal. Analysis product gas he found that the gases in the rapid stage of char gasification at 723 K presented mainly hydrogen and carbon dioxide. The study demonstrates the first time that nickel catalyst can enhance gasification reactivity in a similar manner as observed for activate carbon.

temperatures. The good results exhibited carbon conversion reached 85%, with 30 min for steam gasification at low temperature as 723 K.

Ohtsuka [25] reported calcium catalysed steam gasification of Yallourn brown coal with the same way of preparation catalyst as Tomita have done. The results also showed that high activity for calcium catalyst steam gasification of brown coal.

Takarada [26] investigated catalyst steam gasification of coal by mixing of K-exchange brown coal. The results gave evident that rate of enhancement of K-exchange Yallourn coal by physical mixing method is independent of the caking property of higher rank coal; Potassium is a highly suitable catalyst for catalytic gasification.

Recently, Miki [27] also carried out pyrolysis and gasification of coal which was loaded Ni by ion — exchanged method, and again proved nickel loaded brown coal has a high activity in coal gasification.