Transformation of iron based catalysts (γ-FeOOH α-FeOOH and natural pyrite) to pyrrhotite (Fe1-xS) was investigated in relation to the catalytic activ-ity in the initial stage of direct liquefaction of brown coal. XRD analysis indicated that γ-FeOOH could be completely transformed to pyrrho-tite with smaller crystallite size at 250°C, while only a part of pyrite converted at 350°C with a large crystal growth of pyrrhotite. It was found that remarkable hydrogen con-sumption was observed on the heating to 450°C during the liquefaction of Yallourn coal with γ-FeOOH compared to pyrite catalyst. Results from the analysis in the products suggested that gaseous hydrogen could be activated on Fe1-xS surface, followed by trans-fer to radical fragments produced through the thermal decomposition of coal. It was ascertained that γ-FeOOH had a excellent catalytic activity for hydrogen transfer to radical fragments in the initial stage during the liquefaction of brown coal be-cause of its lower transformation temperature to fine crystallite size pyrrhotite with high surface area, resulted in the higher oil yield with lower hydrogen consumption due to the less formation of hydrocarbon gases.
Silver supported alumina (Ag/Al2O3) catalysts have been developed for removing lean NOx with ethanol. Fundamental aspects of NOx reduction with etha-nol over the Ag/Al2O3 catalyst were summarized. In addition, the results of the bench scale test on the Ag/Al2O3-ethanol system using real lean-burning gas engine and diesel engine exhaust gas were reported. On the basis of these findings, development of catalyst system (Ag/Al2O3+Oxidation catalysts) for the reduction of NOx from the sta-tionary diesel engines was discussed.
IG-MCFC power generation plant efficiency is higher than that of IGCC. We estimated a IG-MCFC power generation plant efficiency that combines O2 blown type or Air blown type gasifire and a wet gas purification unit. First, we surveyed wet gas purification systems in point of motive power and util-ity. Three types of wet gas sulfur absorbing processes (MDEA, Selexsol and DEA process) were investigated. Among these, the motive power and utilities of the MDEA process showed the smallest. We recognized the MDEA process is most hopeful among proposed wet gas sulfur absorbing processes. The thermal efficiency of the IG-MCFC power generation plant was studied using software developed by CRIEPI in 1994. From the results, we concluded that the net thermal efficiency of the system is about 50%.