Technical Papers
Application of Waste Plastic Disposals to Marine Diesel Engines -In case of Marine Residual Fuel-*
by Osami Nishida**, Hirotsugu Fujita**, Wataru Harano**, Phong Hai VU**, Tsuyoshi Fukui**, Hitomi Saito**, Norihiko Toyoshima***
Blending pyrolitic oil (or Waste Plastic Disposal) produced from household and industrial plastic wastes with Marine Heavy Fuel Oil (C.Oil) reduces the viscosity of the heavy oil significantly. The experimental results indicated that, the WPD mixing ratio of 20 vol.% reduces the experimental heavy fuel oil viscosity 90% from 177 cSt to 20 cSt at 50℃. The blended oil has been applied to a small size high-speed single-acting 4 stroke diesel engine (16 horsepowers, 2200rpm) without preheating the oil. The experiment on the engine with non-preheated blended oil has proved the stable performance of the engine. This would lead to the significant reduction of fuel heating cost. Although NOx emission slightly increases, the emission of particulate matters (PM), dry soot (DS) and soluble organic fraction (SOF) decreases by half at the mixing ratio of 30 vol.%.
Key Words: C.Oil, WPD, Diesel Engine, NOx, CO, PM
1. Introduction
Sufficient attention to fuel oil systems, which is one of the primary factors in reactivating marine transportation, is of great importance. To date, the fuel oil used aboard sea-going vessels has been low-grade heavy fuel oil (HFO) (density(1.0g/cm3, kinematic viscosity ＝ 177 cSt @ 50℃ which requires complicated heating systems and excessive heating energy. This results in a hard-working environment for engineer crews due to the high temperature in engine rooms (approximately 45℃〜50℃. Still worse, because of high temperature (about 80℃〜100℃) to which it is heated some fine components of fuel are likely to degenerate or coke.
This study proposes a new use for the heavy fuel oil, on which the engine could operate without heating: mixing heavy fuel oil with oil thermally processed from waste plastics (hereafter called Waste Plastic Disposal or WPD). In previous papers ([1]-[7]) authors have presented the achievement of application of WPD-mixed DO and WPD-mixed A.Oil to diesel engines.
This paper reports the result of application of nonheated WPD-mixed HFO to diesel engines including inspection of the engine performance and exhaust gas characteristics.
2. Characteristics of Experimental Oils
A Ultraviolet ray analyzer (UV-3100PC. Shimazu), a differential thermal gravity analyzer (DTG-50/50H, Shimazu), a X-ray type Sulfur content detector (URA-107) and a GC-Mass spectrometer (LC-VP, Shimazu) were employed to study the experimental oils. Table 1 shows the properties of the marine heavy fuel oil used for experiments. C.Oil's kinematic viscosity at 50℃, density at 15℃ and sulfur content are 177 cSt. 0.982g/cm3 and 2.56 mass% respectively.
Table 2 shows the components of WPD. The mains of WPD are styrene radical, which count for 60% of the fuel volume. The change in the experimental oils' density, kinematic viscosity, CCAI (Calculated Carbon Aromaticity Index) and sulfur content in respect of WPD mixing ratios are indicated in figure 1 and Ultraviolet ray absorbency of the fuels in figure 2. As shown in figure 1, except for the slight rise by 3.6% from 848 to 880 in CCAI value, kinematic viscosity extraordinarily decreases by 90% from 177 cSt to 19.5 cSt at 50℃ at the mixing ratio of 20%. Density and Sulfur content decline by 2.5% from 0.978 to 0.953 and by 30℃ from 2.27 to 1.57 mass % respectively. As indicated in figure 2, along with the increase in the mixing ratio the benzenoid substances in the oils lessen. Figure 3 shows an increasing evaporation rate of the oils in respect to temperature as the mixing ratio increases. The analytical result from a GC-Mass spectrometer, illustrated in figure 4, proves that the blended oil is similar to WPD.
* Translated form Journal of MESJ Vol.35, N0.5 (Manuscript received oct. 22, 1999)
** Kobe university of Mercantile Marine (Higashinadaku kobe city)
*** Nippo Sangyo Company K. K (Daichi-machi, Iwakuni City)
