Katsumi Hirano

Outline of NEDOL coal liquefaction process development (pilot plant program)

Abstract The 150-t/day NEDOL coal liquefaction pilot plant (PP) has validated the superior technical features with a highly active liquefaction catalyst and hydrogen donor solvent. The operation runs without any serious trouble and was successfully executed from March 1997 to September 1998. The results were integrated as a “technical package” and the R&D is transferred to a commercializing phase.

Catalytic activity of iron compounds for coal liquefaction

Abstract The catalytic activity of pyrite and synthesized α-FeOOH in coal liquefaction was investigated using batch autoclaves with the aim of developing an industrial iron catalyst. The results indicate that the presence of H 2 S helps gaseous hydrogen transferring and prevents deactivation so that the catalyst promotes hydrocracking of coal and hydrogenation of the products. The activity converges with excess H 2 S and sulfur addition equivalent to an S/Fe molar ratio of 2.0 being reasonable for the activation. The active site is located on the outer surface, with finely divided catalysts exhibiting high activity. Both pulverized pyrite and synthesized α-FeOOH are sufficiently fine as to exhibit high activity in the process. Pulverized pyrite is an industrially feasible iron catalyst for coal liquefaction process, because it is inexpensive and does not require sulfur addition.

Study on industrial catalyst for bituminous coal liquefaction

Abstract The catalyst activities and the grinding characteristics of natural iron compounds and sulfides were investigated with the aim of preparing an industrial coal liquefaction catalyst for the NEDOL process large-scale plants. From the viewpoint of economy, since these plants are to be located at coal mining sites, it is economical to utilize a natural compound produced in the vicinity of plant site as the catalyst raw material. The coal liquefaction, using an electromagnetic agitation type autoclave, suggested that iron sulfide (pyrite) is the best raw material for the catalyst, because it contains higher iron and sulfur for producing pyrrhotite, an active component under the reacting conditions, and thereby, it needs no pollutant sulfur addition. However, taking into consideration the grinding characteristics, iron sulfide is not thought to have good grinding characteristics in a fine particle zone. Co-pulverization, using iron sulfide and coal, improves the grinding efficiency, the abrasion and the catalyst activities, so that the industrial catalyst preparation can be realized by means of the co-pulverization method.

Liquefaction and dechlorination of hydrothermally treated waste mixture containing plastics with glass powder.

Additive effects of glass powder upon the product yields and chlorine distribution after liquefaction of hydrothermally pretreated mixed waste (HMW) are compared with liquefaction of HMW with any one of water, quartz sand, or glass powder plus water. As a result, addition of either water or quartz sand did not affect liquefaction and dechlorination of HMW. Further, water (5 g) addition did not enhance liquefaction and dechlorination of HMW with glass powder. On the other hand, after liquefaction of HMW with glass powder, the yields of chlorine in the gas and water insoluble constituents decreased and the chlorine yield in the water-soluble constituent increased significantly. Because sodium in glass powder dissolved in a small amount (0.5 g) of water resulted from dehydration of HMW during liquefaction. Further, hydrogen chloride derived from polyvinylchloride in HMW was neutralized by ion exchange between H(+) and Na(+) dissolved in a small amount of water forming NaCl in the Residue (water-soluble) constituent. Therefore, most of chlorine in HMW was removed easily by water extraction of the Residue constituent after liquefaction of HMW with glass powder. Further, upgrading of HMW into the oil constituent was enhanced due to inhibition of production of chlorine containing organic compounds. Accordingly, it was clarified that glass powder was the most effective additive for liquefaction and dechlorination of HMW.

Function of Hydrogenated Solvent in the Coal Liquefaction System.

The influence of heavy distillate in the solvent for coal liquefaction was investigated with a 5L batch-autoclave.The following conclusions are obtained.(1) Heavy distillate in the solvent consumes much hydrogen and prevents hydrogen translation on asphaltene hydrogenating reaction. Consequently, it reduces oil yield in the coal liquefaction system.(2) Donatable hydrogen in the heavy solvent equally promotes coal liquefaction reaction to that in the recycle solvent. Severe hydrotreatment of the heavy solvent increases its hydrogen donatability and oil yield in the coal liquefaction system.