Yasuaki Komiya

PRESSURE SHOCKWAVES TO ENHANCE OIL EXTRACTION FROM JATROPHA CURCAS L

ABSTRACT Kinetic data regarding the intensity of maceration and subsequent pretreatment with pressure shockwaves (50 MPa to 60 MPa) are described in detail and evaluated statistically. Mass balances as well as the study on liquid environment are reported, allowing further process optimization according to financial aspects. It was verified on a laboratory scale by Soxhlet apparatus that oil extraction over 94% may be reached. Achieving such a high level of disintegration opens wide options for application of hydrolysis in order to break apart the remaining lignocellulose cell walls and access the last oil remaining in the vacuoles.

The use of underwater high-voltage discharges to improve the efficiency of Jatropha curcas L. biodiesel production.

Underwater high‐voltage discharges (3.5 kV) resulting in 4.9 kJ shock waves (50–60 MPa) were studied at the laboratory scale as a Jatropha curcas L. seed disintegration method. Grinding and macerating in an excess of methanol (3.5:1) was advantageous because methanol acts both as a liquid carrier for the pressure shock waves and as a solvent that increases the efficiency of oil extraction while remaining usable for esterification. The influence of the number of shock waves and the intensity of methanol maceration on the heat values of the pressed cake are stated in detail. Soxhlet extraction demonstrated that a greater than 94% oil extraction was achieved. The increased disintegration of vacuoles rich in oil was documented by surface area analysis, mineralization kinetics analysis, and electron microscopy. The working volumes were small, and the proportion of energy inadequate compared to the yields released; however, much can be improved by upgrading the process.

Measurement of Soil Deformation at the Ground Contact Surface of a Traveling Wheel

Abstract In order to clarify the soil deformation at the ground contact surface, traveling tests using a rubber-coated rigid wheel were carried out with -5%, 5%, 10%, 20% and 40% slip using a sophisticated soil bin test apparatus. The displacement of soil particles at the ground contact surface was observed through the movement of acrylic wires (1 mm in diameter) laid down on the soil surface. PTV (Particle Tracking Velocimetry), an effective image processing technique, was employed to detect the movement of the acrylic wires using image processing of a series of pictures. The detected movement is assumed to coincide with that of soil particles at the same position. Accordingly, the movement of soil particles could be successfully measured and analyzed. In addition, the soil deformation under the wheel was also measured using PIV (Particle Image Velocimetry). Both measures were then analyzed and the characteristics of soil deformation clarified. The mathematical model for the soil displacement at the ground contact surface showed good agreement with the measured values, except for at high slip.

Influence of Soil Surface Coverage on Soil Deformation by a Traveling Wheel

A model roller was traveled repeatedly along a soil bin with low traveling slip under 3 different coverage conditions; uncovered, and covered by a 1-mm or 3-mm thick rubber sheet. Soil displacement during each traveling was recorded by taking series of pictures through the transparent acrylic soil bin wall and application of image processing. Soil surface coverage affects the size and shape of the soil displacement trajectory for each travel. The soil particles at the deeper layers under coverage by the 3-mm sheet were displaced the furthermost downward among the 3 sets of conditions after only one travel. Coverage by a thick sheet significantly decreased the horizontal displacement of the soil during travel repetition, while that by the thin sheet had the opposite result. The results showed that consideration of soil surface coverage would help in the control of soil compaction.

Soil Deformation beneath a Wheel during Travel Repetition

Abstract To elucidate the phenomenon of the soil compaction observed during actual machine operation, a model wheel was traveled repeatedly and the subsequent soil deformation was analyzed. As repetitive travel progressed, soil particles drew similar trajectories with accompanying changes in the size and shape of the trajectories leading to the formation of spiral-like patterns. The changes depended on traveling slip and depth of the soil layer. The void ratio increased in with repetitions in the shallow layers, but decreased in the deeper layers. The change in void ratio in high slip conditions was larger than those in low slip conditions, indicating that repetitions in high slip caused more deformation and compaction than did those in low slip.

Application of FT-NIR spectroscopy to the evaluation of compost quality

Abstract A rapid and simple method of quality measurement for compost was developed using an FT-NIR technique. Compost samples collected from a composting factory were used for the calibration and validation of components. NIR spectra were measured within the range of 1000–2500nm. Total carbon (TC) and total nitrogen (TN) were measured by N/C Analyzer and mineral contents measured by an Inductively Coupled Plasma (ICP) instrument for calibration and validation. Partial least square regression and multiple linear regression were employed for calibration among the second derivative spectra and measured the mineral content. The calibration models evaluated correct contents of potassium, phosphorus and other minerals of the test composts in received accuracy. These results indicated that NIR spectroscopy was a useful tool for the management of compost quality.