The use of the PCI method, a blast furnace auxiliary fuel supply method which has replaced oil injection, was extended to many additional blast furnaces after the 2nd oil crisis in 1979. It is believed to be one of the most reliable blast furnace fuel injection methods. At present, the technical development of the PCI facilities has almost been completed, and the recent improvement of blast furnace operations has made it possible to use various types of coal, and to increase the PC injection rate to over 100kg/t-pig. In oder to further increase the PC rate, it is necessary to make additional improvements in the blast furnace operations especially in the areas of PC combustion efficiency, burden properties and burden distribution in the furnace. In the near future, the PC rate may reach as high as 200kg/t-pig. The blast furnace operation, which still strongly depends upon the use of coke, is at the present time at a turning point.
This paper describes possible reduction of CO2 emission from fossil fuels in the world. The reduction in this paper means that from the necessary fossil fuelconsumption in 2005 by saving energy with raising thermal efficiency. By raising thermal efficiency, human kind can possibly save energy in four sectors by about 30%;industry, transportation, electric power generation and consumption, and residential and commercial. Since reduction of CO2 emission would also become about 30% in 2005, the total CO2 emission amount would be as same as that in 1986; the total CO2 emission amount would be kept almost constant in coming 15 years. One of the other possible countermeasures would be forestation of the destructed forests or of the dry area. Annual forestation of about 0.4 million km2 would make required forest area to absorb CO2 to reduce CO2 emission by 50% in 20 years.
Tokyo Conference on the Global Environment and Human Response Toward Sustainable Development was held on 11th through 13th September, 1989 addressed two major areas of global concern; “Changing Atmosphere” and“ Development and the Environment in the developing countries”. 60 scientists and politicians from developed and developing countries, free or planned economic countries joined this conference to discuss the technology and policy to seek pragmatic responses of the world to help realize the concept of “environmentally sound and sustainable development” as advocated by the UNEP Governing Council and the World Commission on Environment and Development.
The catalytic activity of natural pyrites powdered finely on the liquefaction of Taiheiyo coal has been investigated. By powdering finely natural pyrites, their catalytic activities on coal liquefaction are enhanced, and their coal conversions are comparable to that in the presence of synthetic pyrite. The effect of their composition on coal conversion is reduced. According to the chemical structural analysis of oil and asphaltene produced in the presence of natural pyrite powdered finely, their carbon aromaticities are lower and their mean length of side chains (Ho/Hα + 1) are longer comparing with those in the presence of synthetic pyrite. These results indicate that natural pyrite powdered finely has a higher activity in the hydrogenation of asphaltene and in the hydrocracking of asphaltene to oil comparing with synthetic pyrite. Among four natural pyrites, pyrite from Shiraoi area (Hokkaido) has the highest hydrogenation ability to produce oils containing the most aliphatic components due to catalytic abilities of mineral matter coexisted.
The hydrotreatments of an Australian brown coal liquid vacuum residue (CLVR) and its solvent-fractionated components were comparatively examined in the repeated runs of single-and two-stage reactions, using a commercial Ni-Mo/Al2O3 (KF-842, presulfided at 360°C-6h in a 5vol% H2S/H2 flow) catalyst and an autoclave of 100ml capacity. The two-stage hydrotreatment of 390°C-2h and 430°C-2h was more effective for the distillate production (-70%) and nitrogen removal (-60%) in both first and third runs, maintaining 15-20% higher levels of distillate yield (DY) and nitrogen removal (HDN) than the single stage of 430°C-4h, and less increment of catalyst weight (ICW), regardless of the feeds. The reactivity and catalyst activity decreased in the order of CLVR-TS (toluene soluble) >CLVR-THFS (THF soluble) >CLVR-OR (original whole), however, the distillate yield, based on the original whole residue, increased in the order of CLVR-TS<CLVR-THFS<CLVR-OR. Based on the above results, higher efficiency of the two-stage hydrotreatment of CLVR is discussed in terms of catalyst design, solvent effects and pretreatments.
In order to evaluate the feasibility of coal derived middle distillates as diesel-powered automobile fuels, mass emission of CO, HC, NOx and particulate matter, and content of soluble organic fraction (SOF) in particulate matter were measured by operating two types of automobiles under 10 mode driving cycle, idle condition and constant speed conditions at 20, 40 and 60km/h. One of the automobiles was conformed to Japanese emission standard in 1982 and the other to standard in 1986 which required more stringent permissible limit for NOx. The middle distillate was obtained from liquefaction of Illinois subbituminous coal followed by catalytic hydrogenation. The test fuels were prepared by mixing the middle distillate and a commercial gas oil, and adding a cetane booster to mixing fuel. The mass emission of CO, HC and particulate matter, and the content of SOF emitted from the automobiles increased with the increase of the middle distillate content in the test fuels, but the mass emission of NOx hardly increased. The emission from the automobile which was conformed to more stringent emission standard for NOx showed stronger dependency on the middle distillate content than the other automobile. Addition of the cetane booster to the mixed fuel improved the ignition quality of the mixed fuel, and decreased the mass emission of CO, HC and particulate matter. Although exhaust emission characteristics of the mixed fuel containing the coal derived middle distillate were improved by adding the cetane booster, it is necessary to make basic property of the middle distillate, such as aromaticity, distillation characteristics and so on., closer to petroleum derived fuel in order to use the middle distillate under more stringent emission standard.