Paying attention to the depletion of the ozone layer due to CFC's, the authors investigated the CFC12 decomposition by electrical method. CFC12 was excited by passing through a corona discharge tube and decomposed to elementary substances in a high electric voltage field. Decomposed gas was introduced into the treatment vessel in which H2O and Ca (OH) 2 were filled in order to control by-products. In this paper, the preliminary experimental data were analyzed, and the CFC12 decomposition rate was obtained by using the gas chromatograph (GC). We found that i) 99% CFC12 decomposition rate was obtained at an input power of about 190W. However, decomposition rate decreased to 30% after 40 minutes from the start of corona discharge, ii) CFC12 decomposition rate increased about 10% by cooling reactor, iii) almost no byproducts were detected in the exhaust gas, while Cl2 and F ions were detected 75ppm and 25-50ppm respectively in the treatment vessel, and iv) CFC12 decomposition quantity by corona discharge process was larger than that of DC arc plasma process.
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.
A new coal pyrolysis method which dramatically increases the total volatiles was presented. A brown coal oxidized by H2O2 at 60°C was extracted up to 80 % by a mixed solvent of methanol/1-methylnaphthalene at room temperature. The extract solubilized in the mixed solvent was pyrolyzed in flash mode at 650 to 850°C. Surprisingly more than 90% of the extract was converted to volatiles. On the other hand, the total volatiles were 70% when the dried extract was pyrolyzed. It was clarified that the dispersion of the extract in the solution and its molecular structure control the pyrolysis behavior. From these results it was demonstrated that the combination of the liquid phase oxidation and the flash pyrolysis of the oxidized coal dissolved in the solvent produced 84kg of volatiles from 100kg of coal.
We presented a new oxidative degradation method to separate the oil palm shell waste into hemicellulose, cellulose, and lignin fractions under mild conditions. It is also meaningful and useful to find another methods to utilize the water-soluble compounds (WSL) that are obtained in 48% yield as intermediates from the oil palm shell. Since the water-soluble organic compounds consist of partly oxidized lignin, their gasification rate is expected to be larger than the gasification rate of the original shell. We examined the possibility to utilize the water-soluble compounds as a feedstock for the gasification by comparing the gasification rates among WSL, the original oil palm shell (OPS) and the shell pretreated by hot water (HTS) using the so-called temperature-programmed reaction (TPR) method in a helium and oxygen gas mixture. The gasification of OPS and HTS proceeded in two steps. It is supposed that the first stage and the second stage gasifications correspond to the gasifications of cellulose and lignin, respectively. On the other hand, WSL was rapidly gasified below 340°C. From the in-situ FTIR measurements it was found that the lignin decomposed into crosslinked structure before being gasified for HTS. On the other hand, WSL was gasified without the cross-linking reaction developing aromatic ring structure. The gasification rate of WSL increased with the progress of conversion and was 500 times larger than that of the oil palm shell at the conversion of 0.9 . This presented the possibility to utilize the lignin fraction as a feed stock for the gasification.