-Coals with carbon contents of 60-80wt% daf were pyrolyzed using a Curie point pyrolyzer at 764-1, 040°C for 5s. In order to explain the effect of coal ranks on product distribution, the cleaving energies of the unit structures of coal were estimated by a reaction coordinate analysis based on the molecular orbital calculation using the WinMOPAC program. The coal pyrolysis reactivity and product distributions were then discussed on the basis of the cleaving energies of the unit structures.
An about 30wt % of raw coal is discharged as a residue from vacuum distillation column in NEDOL coal liquefaction process. Effective utilization of this residue is important to improve profitability of this process. In the present report, pyrolysis and catalytic cracking reaction of four kinds of coal liquefaction residues were carried out by use of a TG apparatus and a GC with pyrolyzer under inert gas to obtain useful chemical compounds from residue. In the TG analysis, the maxmum weight decrease of each sample was observed at the heating rate of 5°C/min. The Illinois No.6 coal residue exhibited larger weight decrease than others. In flash pyrolysis in a GC with pyrolyzer, yields of light fractions, especially gaseous products (C1-C4) increased with increasing reaction temperature. The catalytic cracking reaction with a FCC cata-lyst showed that the yield of light fractions of the shorter retention time than naphthal-ene increased for all residues.
Hydrogen is one of the alternative fuels for preventing air pollution and the greenhouse effect of the earth, but it is lack of portability for automobiles. Ammonia, however, is portable, and can be easily produced from hydrogen and liquefied by compression even under normal temperature. Ammonia is the attractive fuel in the hydrogen energy systems, but its minimum ignition energy is large and its laminar burning velocity is very small. Therefore, the author proposes the clean energy system by using the hydrogen from dissociated ammonia under a catalyst to improve the poor combustion properties of ammonia. The fundamental data of the combustion properties of ammonia and dissociated ammonia with air are obtained by using a slot burner and a spherical combustion bomb. This paper also describes the possibility of the reciprocating engines in which chemical energy of ammonia efficiently converts to power. It is demonstrated that the slow burning speed and the highrequired ignition energy are overcome by adding hydrogen of dissociated ammonia. It is clear that the partially dissociated ammonia engine system has a potential as a promising ammonia-fueled system.
For the purpose of producing saccharides from waste paper, decom-position experiments of several kinds of waste paper such as old news print, flier and paper sludge with hot compressed water were performed by using a batch reactor of 6ml inner-volume. The temperature of water was varied in the range of 250-325°C under the decomposition time of about 60s. After the decomposition, yields of water-soluble and water-insoluble components (WS, WI) in the samples and concentrations of saccharides such as hexose and cellobiose in WS were measured. As the results, the maximum concentration of hexose obtained from old news print under the condition of 286°C and 40s was about 25wt% on WS basis. However, hexose and cellobiose were not obtained from flier, catalogue and sludge from a recycled paper plant. It was found that calcium carbonate in their samples prohibited the saccharification of paper. The addition of phosphate salt was confirmed to be effective for producing hexose from cellulose in the reaction system including calcium carbonate.
71MWe PFBC demonstration plant has been operated since 1992 in EPDC Wakamatsu Work. At PFBC boiler the temperatures of combustion is low, so concentration of NOx in the exhaust gas is kept low. But selective catalytic reaction (SCR) system is adapted for the environmental demand for coal thermal power plants in Japan. Still more, we introduce the selective non-catalytic reaction (SNCR) system and verify the characteristic. In the test, we investigate high efficiency NOx reduction by increase of amount of NH3 injection. Amount of NH3 injection is suitable for more than 1 by [NH3] / [NOx] molar ratio. So far amount of NH3 injection is limited by less than 1 at SCR because of limit of slip NH3 at SCR outlet. But amount of slip NH3 at SCR and SNCR system is as same as one at SCR system. In this paper, we introduce the high efficiency NOx reduction at SCR and SNCR system.