Bio-Diesel Fuel is an alternative fuel for gas oil and has been widely introduced as one method to reduce carbon dioxide emissions. In Japan, bio-diesel produced from waste cooking oil is commonly used. One of the largest facilities is in Kyoto city which has a 5000L/day production capacity and supplies garbage collection trucks and city buses with fuel it produces. Taking this facility as example, the outline of the bio-diesel production process is introduced. In addition, production costs and the CO2 reducing effect the bio-diesel is quantitatively estimated. The cost estimation shows that the biodiesel can be produced for almost the same price as gas oil if tax is excluded. Moreover, CO2 emission is estimated to decrease by 2.0kg for every liter of bio-diesel utilized as alternative fuel.
Yanmar has conducted the research on the utilization of the so-called “FAME” bio diesel derived from waste cooking oil whose quality is worse than European bio diesel fuel standards (EN14214). However, it is an attractive carbon-neutral fuel which does not compete with food. In this study, several endurance tests were conducted on a diesel engine co-generation system using FAME of different properties. Tests show that with FAME fuel operation, lubricant oil dilution occurs due to mixing of unburned fuel. The low quality fuel which includes tri-glyceride led to more carbon deposits around injection nozzle tip causing higher smoke emission.
This paper considers the one area of biofuel usage in the European Union: biodiesel in light duty passenger car diesel engines. By using examples from research undertaken by The Lubrizol Corporation this paper evaluates the impact that the use of biodiesel may have on automotive engine oils designed for use in light duty diesel engines.
The emissions of pollutant metals from marine diesel engines were investigated by an X-ray fluorescence spectrometer. The emission measurements were carried out using two medium speed 4-stroke engines operating on different fuels, which are HFO, MDO, MGO, rapeseed oil, palm oil, used cooking oil and BDF. The specific emissions showed significant variations between the different fuels and given engine loads. The soot emissions of 0.4 -1.6 g/kWh were determined for HFO, which are an order of magnitude larger than those for the other fuels. The soot emissions at 25% load for vegetable oils except BDF significantly increased, being larger than that for MDO. The emissions of impurities, which include sulfur, phosphorus and metals, for used cooking oil showed larger than those for MDO, MGO and the other vegetable oils. Sulfur accounted for about 50-90% of impurities emissions for MDO and HFO. The specific emissions of Ni, V and Zn, known as priority pollutant metals, were about 10 mg/kWh for HFO.
A snake is an amazing animal considering that it can make various motions using only its slender body. Many researches on snake-like robots have focused on ground movement. However, aquatic animals such as sea snakes and eels also move in a meandering motion. Considering these facts, the authors decided to develop an autonomous underwater snake-like robot. As an approach to this goal, a sea snake robot was made to examine the basic characteristics of propulsion. In the experiments, three axial force gauges and two cameras at different angles were set on the robot’s head. The frequency, amplitude, and phase difference which constitute the elements of meandering motion were varied, and the movement and forces acting on the robot were measured for both in-water and in-air operation. From the results of experiments, the characteristics of the propulsion force of snake motion water were discussed.
In a previous report, the authors showed that half of sulfate in particulate matter (PM) was lost during total sampling of PM in a partial flow dilution system. In order to show the cause of this sulfate loss, deposition loss in the dilution tunnel of the measurement system was investigated. Since there is no description about the length of the dilution tunnel of this system in JIS B 8008 which describes the PM measuring method, a guideline for the length of a dilution tunnel was investigated. PM emissions of a laboratory diesel engine were obtained for various lengths of the dilution tunnel. The length of the dilution tunnel was varied between 10 to 40 times the inner diameter of the dilution tunnel. To investigate measurement results, particle diameter measurements of the PM in the dilution tunnel were performed and the deposition fractions of the particles were calculated. The results showed that changes in the length of the dilution tunnel had no meaningful influence on the PM emissions. This is supported by deposition calculation results which showed that the deposition fraction was small compared with the deviation of the PM emission measurements. Thus, a length of 10 to 40 times the inner diameter was obtained as a benchmark for the length of a dilution tunnel in a partial flow dilution system with total sampling.
Electric propulsion is thought to be a more effective propulsion system and with government support the number of ships applying this type of system has increased in past years. However the conventional system requires inverter to change propeller revolution, thus making it very complex and expensive. This is because the system is constructed with basic concept that generator engine should be operated with constant revolution. The authors found that the output frequency and generator voltage are proportional to the generator engine revolution, which is the same phenomena as that of the inverter. With this idea, the authors constructed the “Inverter-less FPP electric propulsion system” and confirmed the effects with simple experiments. Furthermore the system was applied to the model ship “Shioji-Maru”(training ship of TUMSAT). Static performance was confirmed with water tank test.