Extraction of the essential oil of Aquilaria Malaccensis (gaharu) using hydro-distillation and solvent extraction methods

Agarwood oil is regarded as one of the most expensive natural products in the world due to the fragrance inducing compounds it contains. However, current studies on the chemical composition of agarwood essential oil are woefully lacking and this poses a threat to the agarwood industry. This research aims to identify the best extraction method for isolating gaharu essential oil and to create a list of compounds contained in a sample of grade C agarwood. In the present work, the composition of agarwood essential oil obtained through hydro-distillation and solvent extraction with acetone, dichloromethane and hexane as the solvents were analyzed for marker compound identification using gas chromatography-mass spectrometry (GC-MS). Studying another parameter of this experiment, the sample hydro-distillated in the lab was compared with industrial grade hydro-distillation to determine the difference in quality between industrial and lab scale hydro-distillation. Of the three solvents used, acetone eluted the highest number of compounds. The lab scale hydro-distillated sample eluted 34 compounds at a quality of 50% and above whereas the solvent extraction sample eluted 25 compounds. There was no significant difference found between lab scale and industrial scale hydro-distillation

Investigating drag reduction using turbolence altering pseudo-surface (TAPS)

The issue of drag reduction in pipes has already been widely researched and studied. Currently the most popular method for reducing drag in pipes employed commercially is through the use of additives. However, these additives do have drawbacks such as mechanical degradation, altering the chemical and physical properties of the fluid they inhabit as well as being toxic and non-biodegradable for the most part. This has spurred new research aimed to exploring more nature friendly, non-additive means of drag reduction. Among these techniques the most popular ones include riblets, dimples,oscillating walls, compliant surfaces and microbubles but each of these techniques have their respective drawbacks especially when considered for drag reduction in pipes. The present study introduces a novel non-additive technique that employs narrow strips of flexible elastic material in an arrangement mimicking the tentacles of a squid. This form of biomimickry has been frequent among the non-additive methods mentioned previously. The device which has been named the Turbulence Altering Pseudo-Surface (TAPS) consisted of 12 strips of elastic material (neoprene and silicone were tested in this study) of varying lengths of 0.2m, 0.3m, 0.4m, 0.5m, 0.6m and 0.7m with 0.005m width and 0.003m thickness each. The %DR was measured across 4 different testing section lengths, 0.5m, 1.0m, 1.5m and 2.0m spans. The flowrates tested were 6.0m /h, 6.5m 3/h, 7.0m 3/h,.5m 3/h, 8.0m 3/h, 8.5m 3/h, 9.0m 3/h and 9.5m 3/h. The results of the series of experiments carried out were both stimulating and intriguing. On one hand, the maximum %DR achieved is 65% with TAPS made of 0.6m strips of neoprene, but this is followed by an immediately negative pressure gradient change across the consecutive testing sections. On the other hand for TAPS made of 0.7m silicone strips, there is a peak recorded at 42.7% DR with considerable persistence of effect further downstream across the proceeding testing sections. These results raise a perplexing question of whether a localized high %DR is preferred or if a smaller but persisitent effect is better for flow improvement purposes. Whichever the case, this research has profound and important implications for the future of drag reduction in pipes as it has dispelled one of the age old myths, that reducing the effective pipe diameter always results in an increase in drag. There is immense potential in this field of research and plenty of room for improvement in future works

Synthesis of calcium ferrite photocatalyst for the COD photodegradation of palm oil mill effluent under visible light

Malaysia has long battled with the issue of palm oil mill effluent (POME) pollution which has proven to be detrimental to the environment. Although some attempts to alleviate this problem using ZnO and TiO2 photocatalysts under ultra-violet irradiation have been undertaken, these have shown significant room for improvement. The low light utilization as well and mediocre photodegradation efficiency produced by these two systems highlight the need for a visible light driven photocatalyst as a long term solution to the problem. This thesis explores the application of CaFe2O4 as a visible light driven photocatalyst towards addressing that problem. Two synthesis routes namely the auto-combustion (AC) and co-precipitation (CP) routes and two calcination temperatures (550 °C and 700 °C) were used to produce a total of four CaFe2O4 catalysts namely AC550, AC700, CP550 and CP700. CP550 exhibited the greatest chemical oxygen demand (COD) degradation of 69% at a 0.75 g/L catalyst loading and an oxygen flow rate of 60 ml min-1 after 8 h of irradiation. The reaction adhered well to first order kinetics with a rate constant of 2.7 x 10-5 min-1. Nitrogen physisorption studies indicated CP550 had the highest Brunauer-Emmett-Teller (BET) specific surface area (27.28 m2/g) and pore volume (0.077 cm3/g) of the prepared photocatalysts which dropped precipitously for CP700 upon increasing the calcination temperature to BET specific surface area of 9.73 m2/g and pore volume of 0.025 cm3/g due to annealing which created a smoother surface area as evidenced by the scanning electron microscope (SEM) images. Ultraviolet-visible diffuse reflectance spectroscopy (UV-Vis DRS) indicated CP550 had the highest band-gap (1.52 eV) which is likely due to the presence of CaFe5O7 which is a unique structure of CaFe2O4 containing three units of FeO in a stable phase as deduced from the energy dispersive X-ray microanalysis (EDX) data and confirmed by X-ray diffraction (XRD) peaks. CP550 also displayed the lowest photoluminescence (PL) spectra of the as prepared photocatalysts indicating a low electron-hole recombination rate. A scavenging study using iso-propyl alcohol (IPA) caused a severe drop in COD degradation from 69% to just 7% indicating hydroxyl radicals as the main reactive oxidative species. The recyclability study indicated that reusing the spent catalysts led to a decrease from 69.0% to 65.0% and finally 61.0% on subsequent cycles indicating some loss of activity over time. Post reaction characterization of the spent catalyst indicated that the loss of activity was due to carbon deposition as evidenced by FTIR and EDX data. This research contributes to the body of knowledge addressing the issue of visible light driven photocatalysis for the amelioration of recalcitrant environmental pollutants such as POME

Flexible Turbulence Absorbers for Enhancing the Liquid Flow in Pipelines

In the present work, an additive-free new technique for enhancing the flow in pipelines is introduced. Such technique depends on inserting Turbulence Altering Pseudo-Surface, TAPS with certain dimensions inside the pipe (adjacent to the inner wall). Such technique is meant to simulate the viscoelastic behaviour of soluble additives to enhance the flow in pipelines. Liquid circulation system with a testing section divided into four subsections was used to test the drag reduction effect of the new technique. The results showed that almost 60% flow enhancement is achievable when inserting 12 strips with 60 cm length into 0.0381 m diameter pipe

Novel Turbulence Absorption Technique for Enhancing the Liquids Flow in Pipelines

In the present work, an new technique for enhancing the flow in pipelines is introduced. Such technique depends on inserting Turbulence Absorbing Unit, TAU with certain dimensions inside the pipe. This unit was designed to absorb and redirect the turbulent structures inside the pipelines. Liquid circulation system with a testing section divided into four subsections was fabricated and used to test the drag reduction effect of the new technique. The results showed that almost 30% flow enhancement is achievable when inserting 12 strips with 20cm length into 0.0381 m diameter pipe