Tetsuya Deguchi

CHARACTERIZATION OF UPGRADED BROWN COAL (UBC)

ABSTRACT Large amounts of coal resources are found throughout Indonesia. The coal resources amount to 58 billion tonnes, of which about 86% are classified as lignite and sub-bituminous coals that are usually referred to as low rank coals (LRCs). The utilization of LRC causes some problems, such as spontaneous combustion and difficulties in transport and handling. Because LRCs have high moisture content, various dewatering and upgrading processes have been developed to generate a more commercially acceptable, lower moisture product. One of these processes is the Upgraded Brown Coal (UBC) process developed by Kobe Steel Ltd. In this study, an Indonesian LRC was processed using the UBC bench scale unit of 100 kg/day at a temperature of 150°C and a pressure of 350 KPa using kerosene as the process media. To prevent the increase of equilibrium moisture content in the dried coal, the addition of low sulfur wax residue (LSWR) was needed. The characteristics of both the raw and the upgraded product have been studied, i.e.: • Proximate and ultimate analysis. • Combustion characteristics by differential thermal and thermo gravimetric analysis (DTA-TG). • Cross point temperature (CPT) to study liability towards spontaneous combustion. • Physical characteristics of surface area. • Functional group (C‒H and C˭O) analysis using FTIR (Fourier transformation infrared) spectrometry.

Isolation of manganese peroxidase-producing mutants of the hyper-lignolytic fungus IZU-154 under nitrogen nonlimiting conditions

Abstract Nitrogen deregulated manganese peroxidase (MnP)-producing mutants of Deuteromycotina IZU-154 were isolated based on their ability of decolorize synthetic melanin. One of these mutants, IZU-882, exhibited an approximately 2-fold higher level of MnP activity, 8–12 nkat/ml (nano katal/ml), under nitrogen nonlimiting conditions than that of the wild-type under nitrogen limiting conditions.

NADH Oxidation by Manganese Peroxidase with or without α-Hydroxy Acid

NADH oxidation by manganese peroxidase (MnP) was done in a reaction mixture including either α-hydroxy acid or acetate. The oxidation in the former reaction mixture was inhibited by a catalase and was accelerated by exogenous H2O2, while the oxidation in the latter reaction mixture was inhibited by a superoxide dismutase and was not accelerated by the exogenous H2O2. These results indicated that there are significant differences between the two reaction systems, particularly, in the active oxygen species involved in the reactions. Additionally, the experiment of MnP reduction with Mn(II) suggests that MnP has a separate catalytic activity other than an oxidation of Mn(II) to Mn(III) in the reaction mixture including acetate.

The indicative culture parameters of manganese peroxidase production by white rot fungus IZU-154

The production of manganese peroxidase (MnP) by the hyper-ligninolytic fungus IZU-154 was performed by batch and filter-cultivation using a conventional stirred fermentor. A maximum MnP activity of 9.7 nkat/ml (nano katal/ml) was obtained after 44 h in the batch cultivation, and that of 8.1 nkat/ml was observed after 20 h in the filter-cultivation. Culture parameters, such as redox potential and pH, were investigated in the batch cultivation. We also investigated a novel parameter, the nonenzymatic 2,6-dimethoxyphenol oxidation (NEOX) level, which seems to reflect the amount of Mn(III) oxidized from Mn(II) by MnP. The swift rise of the redox potential, the synchronous gradual rise of pH, and the saturation of the NEOX level were significantly correlated to the MnP production. The production of MnP and the onset of the profiles of parameters were apparently in response to Mn(II) addition to the culture fluid. Furthermore, we investigated the content of organic acids during the MnP production in the filter-cultivation. Tartrate contained in the culture medium was consumed coincidentally at the onset of MnP production, and oxalate and formate were newly produced in the culture fluid at the same time.