Production of biodiesel from waste cooking oil using ultrasonic tubular reactor

The aim of study is to produce the synthesis of biodiesel from waste cooking oil (WCO) using ultrasonic tubular reactor at laboratory scale. The experiment was used to determine the effect of ester contents by reaction time, molar ratio of WCO to Methanol (MeOH), amount of catalyst, frequency of ultrasonic and ultrasonic output power using ultrasonic tubular reactor. Based on the optimum process by ultrasonic tubular reactor, a comparisons study of three different processes (ultrasonic tubular reactor, conventional ultrasonic cleaner and mechanical stirring) were also investigated. The optimum results of biodiesel process using ultrasonic tubular reactor are the reaction time of 5 minute, sodium hydroxide (NaOH) catalyst 1%wt of WCO, molar ratio WCO to MeOH of 1:6, frequency ultrasonic of 20 KHz and ultrasonic output power of 650 Watt. The reaction time was reduced to 12-24 times (minute) compare to mechanical stirring and the ester contents was obtained at 96.54%wt. The ternary phase diagram ultrasonic tubular reactor was to find out the liquid liquid-equilibrium base on WCO- Fatty Acid Methyl Esters (FAME) -MeOH. The results show that by increasing the residence time of the whole reactant system within the two-phase zone is good for the reaction transesterification on ultrasonic tubular reactor. The semi continuous ultrasonic tubular reactor for biodiesel process of WCO gave conversion of WCO to FAME of 98%wt with flow rate of 5.56 ml/s. Meanwhile, the pilot plan of biodiesel facilities using mechanical stirring method (capacity of 100 kg WCO/batch) was designed and the transfer knowledge about biodiesel process was a success between the university with industry in Batu Pahat

Assessment of mortar evolution in pig slurry by mechanical and ultrasonic measurements

This work presents the results obtained in a long-term experiment focused on the study of the evolution of cementitious materials immersed in pig slurry at real conditions. Cement mortars were made with four different cement types and immersed in pig slurry for 48 months. Furthermore, to separate pure hydration process from pig slurry effect, mortar samples were immersed in water for 12 months at laboratory conditions. Compressive strength, X-ray diffraction and ultrasonic measurements were made in all samples. Ultrasonic measurements were made from ultrasonic images obtained from automatic ultrasonic inspections. Use of ultrasonic images has allowed the extraction of information about the state of the studied materials. An empirical relationship between ultrasonic velocity and compressive strength has been obtained and the long-term effect of pig slurry on cementitious materials has been determined

A miniature surgical drill using ultrasonic/sonic frequency vibration

A study is presented of a miniature ultrasonic surgical drill designed for bone biopsy, based on an ultrasonic/sonic drill which converts high frequency to low frequency vibrations through a freely vibrating mass between an ultrasonic transducer-horn and a drill bit. For conventional surgical drilling using a rotary drill or an ultrasonic drill, considerable power is required to penetrate into bone and the efficiency is low. However, for ultrasonic/sonic drilling, sufficient acoustic energy is accumulated and then released through each impact to achieve precise drilling with a lower power requirement. The ultrasonic/sonic drill was originally invented for rock drilling in low gravity environments. In this study it is incorporated in a miniature ultrasonic surgical drill and the effective impulse delivered to the bone is used to evaluate the drilling performance. To develop a miniature surgical device based on maximising the effective impulse, optimisation of the ultrasonic horn and free-mass is first demonstrated. The shape and dimensions of the ultrasonic horn and free-mass are determined through FEA, which focuses on maximising the post-collision velocity of the free-mass. Then, the entire dynamic stack constituting the surgical drill device is modelled as a mass-spring-damper system to analyse the dynamic behaviour. The numerical model is validated through experiments, using a prototype drill, which record the velocity of the free-mass and the drilling force. The results of the numerical models and experiments indicate this miniature ultrasonic surgical drill can deliver sufficient impulse to penetrate bone and form the basis of an ultrasonically activated bone biopsy device

Correlation established between heat transfer and ultrasonic transmission properties of copper braze bonds

Measuring and correlating the thermal conductivity and ultrasonic transmission of seven hot-brazed-bonded copper plates established a relationship between heat transfer and ultrasonic transmission properties of the bonds. This relationship permits the prediction of heat transfer characteristics from ultrasonic transmission tests

Possibilities of using the ultrasonic wave transmission method to estimate initial setting time of cement paste

In this paper, the applicability of the ultrasonic wave transmission method to estimate the initial setting time of an arbitrary cement paste is discussed. Ultrasonic pulse velocity measurements were fully automated and measured continuously. The Vicar Needle Test was used in order to determine the initial setting time of cement pastes. Different cement pastes were prepared in order to check the influence of the water/cement ratio, type of cement, curing temperature, cement fineness, and some clinker compositions, on the relationship between the initial setting time and ultrasonic pulse velocity. It was found that the initial setting time of an arbitrary cement paste can be estimated very accurately by the time the first inflection point appears on the ultrasonic pulse velocity curve. Moreover, it can be estimated quite accurately by the time the ultrasonic pulse velocity reaches a fixed value, close to the value of the ultrasonic pulse velocity in water

Apparatus for recovering matter adhered to a host surface

The development of an apparatus for removing and recovering matter adhered to a host surface is described. The device consists of a pickup head with an ultrasonic transducer adapted to deliver ultrasonic pressure waves against the material. The ultrasonic waves agitate the material and cause its separation from the surface. A vacuum system recovers the material and delivers it to suitable storage containers

Effects of ultrasonic waves on enhancement of relative volatilities in methanol-water mixtures

The application of ultrasonic wave in various fields including separation process has increased predominantly. This paper reports the practicability of using ultrasonic wave to enhance separation of binary mixtures by distillation. The binary mixture utilized was methanol-water. The effect of different ultrasonic intensity at 50, 100, 200 and 250 W/A.cm2 with frequency of 40 kHz to vapor-liquid equilibrium (VLE) of methanol-water was investigated to obtain the most suitable operating intensity. Experimental studies were also carried out to investigate the frequency effect (25 and 68 kHz) to VLE data. It was found that the use of ultrasonic wave enhanced the separation process by increasing the relative volatility of components. The highest average relative volatility of methanol-water at 29.413 was obtained from experimental study using intensity 200 W/A.cm2 and frequency of 25 kHz. The changes in relative volatility and VLE were caused by cavitational activities and vacuum effect that occur during transmission of ultrasonic wave in liquid medium. The results from this study proved the practical feasibility of using ultrasonic wave to enhance separation of binary mixtures in distillation column

The Use of Ultrasonic Frequencies as a Mechanism for Refining

The objective of this thesis was to explore the use of ultrasonic frequencies as a mechanism for refining. Through cooperation with the Intex Corporation, an ultrasonic cleaning apparatus, that was easily adaptable to.use as a refiner, was borrowed. The experimental procedure indicated that ultrasonic refining coupled with mechanical ·refining produced a sheet with improved tear, tensil, fold and opacity characteristics. The burst, however, was slightly lower. An interesting phenomenon that occurred was the plateauing effect that is observed, most distinctly on the graphs of burst and tensil vs. freeness. this plateau seems to be a phenomenon where the maximum value of a test is held relatively constant over a wide freeness range. The peaking, and quick fall off that occurs with mechanical refining is not present with ultrasonic refining. One problem that exists is that the ultrasonic power requirements appear to be relatively high

Development of an ultrasonic resonator for ballast water disinfection

Ultrasonic disinfection involves the application of low-frequency acoustic energy in a water body to induce cavitation. The implosion of cavitation bubbles generates high speed microjets >1 km/s, intense shock wave >1 GPa, localized hot spots >1000 K, and free-radicals, resulting in cell rupture and death of micro-organisms and pathogens. Treatment of marine ballast water using power ultrasonic is an energy-intensive process. Compared with other physical treatment methods such as ultraviolet disinfection, ultrasonic disinfection require 2 to 3 orders of magnitude more energy to achieve similar rate of micro-organism mortality. Current technology limits the amount of acoustic energy that can be transferred per unit volume of fluid and presents challenges when it comes to high-flow applications. Significant advancements in ultrasonic processing technology are needed before ultrasound can be recognized as a viable alternative disinfection method. The ultrasonic resonator has been identified as one of the areas of improvement that can potentially contribute to the overall performance of an ultrasonic disinfection system. The present study focuses on the design of multiple-orifice resonators (MOR) for generating a well-distributed cavitation field. Results show that the MOR resonator offers significantly larger vibrational surface area to mass ratio. In addition, acoustic pressure measurements indicate that the MOR resonators are able of distributing the acoustic energy across a larger surface area, while generating 2-4 times higher pressures than existing ultrasonic probes