Pitch precursors affording excellent spinnability, high-level oxidation-resistance, and good carbonization yields were prepared by bromination–dehydrobromination of various ratios of pyrolyzed fuel oil and coal tar pitch. The pitches exhibited spinnabilities that were much better than those of pitches prepared via simple distillation. A pitch prepared using a 1:2 ratio of fuel oil and coal tar pitch exhibited the best tensile strength. Pitch fibers of diameter 8.9 ± 0.1 μm were stabilized at 270 °C without soaking time after heating at a rate of 0.5 °C/min and carbonized at 1100 °C for 1 h after heating at 5 °C/min. The resulting carbon fibers exhibited a tensile strength, elongation, Young’s modulus, and average diameter of 1700 ± 170 MPa, 1.6 ± 0.1%, 106 ± 37 GPa, and 7.1 ± 0.2 μm, respectively.

Injection rate characteristics of biodesel fuels according to the blending ratio was described in this work. The injection rate measuring system based on the Bosch's method was utilized to measure and compare the fuel injection rate characteristics. Three different types of biodiesel which were derived from seed, unpolished-rice, and soybean were blended with the diesel fuel in 20% and 40% of volumetric ratio. The fuel properties, injection mass, and injection rate characteristics were obtained and compared in various injection conditions. It is expected that this observations provide important insights into the effect of fuel properties on the biodiesel fuel injection rate performance in a CI engine

This study investigates experimentally Air-fuel ratio feedback control with a fuel valve in a LPG engine. The fueling valve is controlled by electronic control unit which is made with micro computer. Various control logics are employed and then PID control is adopter as a proper logic for own system and Air-fuel ratio feedback control by PID control was experimentally of various operation area with the stable control algorithm of PID control that was earned from the former experiment. On the process the experiment, determination experiment of each control part coefficient was the biggest variable among the whole result of experiment. We could know as a result of experiment that the lange of overshoot is bigger as the proportional control part os bigger integral control part is related with the delay time and coefficient of differential control part is related with the decrease of overshoot range from the experiment of various operation area we could also analyse consequently that direct fuel control in the fuel value makes more stable control status in rare operation and low load area.

This study executed evaluation of drying characteristics based on the polymer injection rate (8%, 10% and 12%) and the drying method[NIF(near-infrared ray). According to this study analyzed VS, VS/TS, and calorific value compared with ‘the auxiliary fuel standard of the thermoelectric power plant and the combined heat & power plant’. The results are as follows. In the case of NIR, the VS was slightly changed at the early stage of the material preheating period and the constant drying rate period with low moisture evaporation. But VS reduction was shown higher as moisture was dried. In the case of non-digested sludge with high VS content, the VS reduction rate by drying was shown lower than that of digested sludge. As the flocculant injection rate increased, the VS loss due th drying was found to be small. Also, the higher the flocculant injection rate was the longer the drying time. Especially, in the case of the NIR drying equipment, as the moisture content of sewage sludge decreased(moisture content 20∼40%), the loss of net VS also showed a tendency to increase sharply. It is shown that the high calorific value according to the drying time of the non-digested sludge was changed from 590 ㎉/㎏ to 3,005 ㎉/㎏ and from 539 ㎉/㎏ to 2,796 ㎉/㎏.

The fuel characteristics, the combustion characteristics, and the kinetic study of sample that had been torrefied at 250 ~ 300oC were investigated for orange peel, rice husks, wood chips, and wood pellets. When higher torrefaction temperature was used, reduction of the yield, and increase in the fuel ratio, and decrease of volatile content were found. As a result, improvement of the fuel characteristics was confirmed. As parameters for the combustion characteristics, initial temperature (IT) was rised slightly because of the high torrefaction temperature of the wood chip, and burnout temperature (BT) showed lowered. The combustion time (tq) of torrefied wood chip (TC) is shorter than raw sample, and unburned carbon generation will be suppressed. The activation energy of the char combustion reaction (2nd) is reduction compared to the raw sample, and the pre-exponential factor was decreased. As a result, the combustion reaction rate constant (k) of the torrefied wood chips, should be determined considering the activation energy and the pre-exponential factor.