Artificial Coalification of the Low-rank Coals in Hokkaido Coals

The present report deals with the articial coalification of Tokachi and Tsuchiya lignites and Tenpoku coal which are the low-rank coal in Hokkaido coals, in order to make clear the constitution of the materials produced by the artificial coalification of them and the mechanism of the artificial coalification.After 50g. of the powdered sample of those coals was placed in a stainless steel autoclave of shaking type (capacity 11.) with 400ml. of water, the air in the autoclave was replaced with nitrogen. Then the powdered sample in the autoclave was heated at 200, 250 and 300°C for 8, 24, 40 and 72hr. under gas-steam pressure at about 20, 50 and 120 atm.(gaug pressure).The structural elements othose coals and the artificial coalification products of them were estimated by the van Krevelen's densimetric method for the structural analysis of coals. The composition of gas produced in the coalification was determined.Then the artificial coalification of Tokachi lignite coincided with the natural coalification band of Hokkaido coals in the atomic H/C versus O/C diagram. It of Tsuchiya lignite advanced roughly along line describing the process of dehydration in that diagram. It of Tenpoku coal advanced between the two lines describing the process of artificial coalification of the others.