It is essential part for the CBM research to study on high coal rank and low coal rank CBM reservoiring and their comparison.

The result is found out that the evolution of adsorption capacity and potential are well-regulated with coal rank.

Effects of coal rank and macerals on extractionyield are discussed respectively.

FT-Raman spectroscopic characterisation of chars from the pyrolysis of coals of varying rank;

CBM resource was enough in China, which included the low rank and high rank CBM reservoirs.

In China, coal can be divided into five metamorphism levels—ten coal steps.

For making best use of low rank coal which came up to 40% in China's total coal reserve,the new method of gradual gasifying of low rank coal was put forward,namely,mild gasification and its heat coalite gasified continuously under high temperature,and the market and profits of its product were analyzed.

The resources, production, consumption and classification of low rank coal in the world have been described.

The resources of low rank coal in the world have introduced in this paper.

In this study,the effect of anthracite rank and binders on the reactivity of anthracite formed cokes were major objects.

Exploration and development of CBM from low-rank coals have been very successful in the world,and its exploration potential in China is very large because China is very rich in such resource.

CBM gas reservoirs in low-rank coals are featured by large thickness of coal seams,high permeability,low gas content,and high adsorption saturation.

In recent years, the rapid development of the coalbed methane accumulation theory and exploitation technology have led to the successful development of low-rank coalbed methane accumulations, continuous thin-layer methane accumulations and high-rank, low-permeability coalbed methane accumulations, which has greatly widened the coalbed methane development scope.