Development of Industrial Catalyst for Coal Liquefaction

The NEDOL process, a bituminous coal liquefaction method developed by the New Energy Development Organization (NEDO), is characterized by its high oil yield from wide ranging coal under the mild reaction conditions.Pyrite pulverized into a sub-micron size with coal derived solvent performed high catalytic activity through the operation of the NEDOL 150t/d pilot plant. Although pyrite is so hard that the catalyst-preparing unit consumed large grinding power, caused severe abrasion, and thereby showed that a large problem was left for enlargement to the demonstration plant (DP) and the commercial plants (CP).Therefore, a supplementary research was carried out to select raw materials of the coal liquefaction catalyst applicable to DP, and to decrease in the grinding power and the abrasion for designing a concept of the catalyst-preparing unit for DP. The following results are obtained.(1) From the viewpoint of the catalyst activities, the raw materials of large iron contents regardless of the chemical compositions have to be chosen. Taking the grinding characteristics into consideration, the raw materials having smaller crystal sizes than the ground sizes and having small Wi, c (corresponding work index) in the grinding zone have to be selected.(2) The natural iron-compounds, such as pyrite, have the high catalyst activities, as they don't have easy grinding characteristics. The co-pulverization method in grinding the natural iron-compounds mixed with coal of lower hardness, can decrease in the abrasion and increase in the catalyst activities.(3) A concept of catalyst-preparing unit adopts the co-pulverization method is designed for 5, 000t/d DP.