Width of plastic layer zone was measured in the packed coals heated in a chamber oven by microscopic observation after the rapid quenching to define influen-tial factors related to coals and carbonization conditions. Coals of fluidity in a broader range of temperature formed a wider plastic zone, while more inerts in the coal reduced the width. The carbonization pressure induced 'by volatiles trapped in viscous products ex-panded the plastic zone increasing its width. Broader temperature distribution in the pack-ed coal which was brought about by the migration of fused coal of high fluidity into the zone of lower temperature increased the width, practically by the fusion and dissolution of coal particle by the aid of coal fluid. Such all factors related to the carbonization properties of coals are compared with their petrographic composition and reflectance.
The coke dry quenching method (CDQ) has an advantage over the coke wet quenching method from the following points: 1) not to worse the coke quality and 2) being convenient to recover the heat of hot coke. CDQ is a kind of counter-current mov-ing-bed heat exchanger where the quenching gas flows through the descending hot coke. The rational design procedure for the highly efficient CDQ is not, however, established yet. In this study, we try to estimate the characteristcs of heat and mass transfer in CDQ for improvement of the heat recovery performance. In the computation, the finite element method is used to fit with the geometrical connfiguration. As a result, the predicted outlet temperature of the quenching gas and the lump coke is in agreement with the experimental result. Both temperatures of the quenching gas and the lump coke exhausted from CDQ are decreased by the endothermic reaction between the lump coke and the very small contents of H2, O2, CO2 in the quenching gas. In the CDQ having a radial diistribution of the lump coke diameter, computed results are as follows: the quenching gas deflects having a non-uniform velocity distribution and the outlet gas temperature and the heat collection per-formance are decreased.
Gas hold-ups were measured in a 240mm dia. and 2400mm high three-columns-in-series reactor of the 2.4ton/day NKK direct coal liquefaction process. All measurements were carried out under high pressure in i) two-phase creosote oil/ hydrogen system at room temperature, ii) two-phase anthracene oil/hydrogen and iii) three-phase Illi-nois No.6 coal slurry/hydrogen systems at high temperature by the following three diffe-rent methods; “gas shut-down”, “neutron attenuation” and “gas purge” techniques. For system i), the gas hold-up, εG, obtained by the three methods showed no signifi-cant difference and increased with the superficial gas velocity, UG. εG at a given UG in-creased with the pressure up to 12.8MPa and then leveled off with the further pressure in-crease. These variations of εG could possibly be attributed to those of the bubble size. The change of εG with UG for system ii) was found to be equivalent to that for system i), if changes in UG and the gas-liquid equilibrium composition due to evaporation of light anthracene oil fractions to the gas phase were appropriately evaluated. Furthermore, εGS for system iii) agreed reasonably well with those reported for coal liquefaction pilot plants and high pressure bouble column.
The coal gasification process in a flash hydropyrolysis was investi-gated by comparing CP/MAS 13C-NMR spectra of the raw coal and its solid product (char). The results with Loy Yang coal indicated that aliphatic carbon and oxygen bonded to aromatic carbon initially existed in coal disappeared from chars produced at temperatures higher than 705°C, and that the amount of aromatic carbon remained constant among coal and chars at 705, 725 and 750°C, and then it was progressively reduced as gasification temperature was raised (800, 875 and 950°C). Reduction of aromatic carbon in pyrolysis at about 900°C occurred with similar rates among eight coals ranging from lignite to low-rank bituminous coal excespt for two coals.