Potential use of coconut husk-based magnetic sorbent for defoaming application

Absorption process is the most common method that is being applied to sweeten sour gas in the oil and gas industry. However, this process does have several consequences which will trigger the foam formation of foam that will reduce the mass transfer efficiency and absorption capacity as well as amine solutions carryover to the downstream processes. The removal of undesired contaminants in activated methyldiethanolamine (MDEA) was conducted by utilizing magnetic activated carbon (MAC). In this work, MAC was synthesized from coconut husk through chemical activation and co-precipitation methods. The performance of this material as an adsorbent was evaluated based on the foaming behaviour of activated MDEA solvent after being contacted with MAC at different duration and varying amounts. Nitrogen gas was introduced into the solvent through a gas diffuser to create foam. Based on the results, the foam volume generated by activated MDEA solvent was identified to decrease with the increase in both MAC contact time and amount. The highest removal efficiency by MAC was identified to be at 1 h contact time between MAC and activated MDEA solvent where the foam breaking time was reduced to 10–30 min. Meanwhile, the addition of 50 % MAC into the solvent was able to further decrease the foam breaking time to 5–10 min. The characteristics of the prepared MAC were evaluated through various instrumental analyses. This study shows that the MAC synthesized from coconut husk has a good potential as an adsorbent in removing the contaminants in activated MDEA solvent to reduce foam formation

Potential use of coconut husk-based magnetic sorbent for defoaming application

Absorption process is the most common method that is being applied to sweeten sour gas in the oil and gas industry. However, this process does have several consequences which will trigger the foam formation of foam that will reduce the mass transfer efficiency and absorption capacity as well as amine solutions carryover to the downstream processes. The removal of undesired contaminants in activated methyldiethanolamine (MDEA) was conducted by utilizing magnetic activated carbon (MAC). In this work, MAC was synthesized from coconut husk through chemical activation and co-precipitation methods. The performance of this material as an adsorbent was evaluated based on the foaming behaviour of activated MDEA solvent after being contacted with MAC at different duration and varying amounts. Nitrogen gas was introduced into the solvent through a gas diffuser to create foam. Based on the results, the foam volume generated by activated MDEA solvent was identified to decrease with the increase in both MAC contact time and amount. The highest removal efficiency by MAC was identified to be at 1 h contact time between MAC and activated MDEA solvent where the foam breaking time was reduced to 10–30 min. Meanwhile, the addition of 50 % MAC into the solvent was able to further decrease the foam breaking time to 5–10 min. The characteristics of the prepared MAC were evaluated through various instrumental analyses. This study shows that the MAC synthesized from coconut husk has a good potential as an adsorbent in removing the contaminants in activated MDEA solvent to reduce foam formation

Graphene-oxide coated on fiber Bragg Grating for temperature sensor

The rapid development and deployment of optical sensors have brought fibre Bragg grating (FBG) as a renowned optical sensor which acquired high sensitivity, fast response to the measurement changes and small in size. However, the implementation of bare FBG sensor could be further enhanced to give significant impact in terms of sensitivity without any alteration on the effective refractive index and the grating period. Therefore, a low cost and high temperature sensitivity of fiber Bragg grating (FBG) sensor coated with graphene oxide (GO) is designed and constructed. The FBG is synthesized with GO by implementing dip coating technique. Then, the bare and coated FBG sensor is tested by applying heat at the grating region of the FBG. The output of the experiment is displayed on the optical spectrum analyzer (OSA) in terms of power (dBm) and wavelength (nm). The performances of the FBG sensors have been evaluated by comparing the temperature sensitivity. The GO-coated FBG recorded better temperature sensitivity of 16.0 pm/°C compared to the bare FBG with sensitivity of 15.0 pm/°C. The results indicate the ability of graphene oxide to improve the Bragg wavelength shift by the combined effect of effective refractive index and grating period that are influenced by the changes of temperature. GO-coated FBG also exhibits better linear fit of 99.1%, which specifies the consistency of the wavelength shift reading as temperature increased and low limit of detection (LOD) compared to the bare FBG as the minimum value of LOD signifies the effectiveness of the senso

Integration of an On-Axis General Sun-Tracking Formula in the Algorithm of an Open-Loop Sun-Tracking System

A novel on-axis general sun-tracking formula has been integrated in the algorithm of an open-loop sun-tracking system in order to track the sun accurately and cost effectively. Sun-tracking errors due to installation defects of the 25 m2 prototype solar concentrator have been analyzed from recorded solar images with the use of a CCD camera. With the recorded data, misaligned angles from ideal azimuth-elevation axes have been determined and corrected by a straightforward changing of the parameters' values in the general formula of the tracking algorithm to improve the tracking accuracy to 2.99 mrad, which falls below the encoder resolution limit of 4.13 mrad

Integrated Microfibre Device for Refractive Index and Temperature Sensing

A microfibre device integrating a microfibre knot resonator in a Sagnac loop reflector is proposed for refractive index and temperature sensing. The reflective configuration of this optical structure offers the advantages of simple fabrication and ease of sensing. To achieve a balance between responsiveness and robustness, the entire microfibre structure is embedded in low index Teflon, except for the 0.5–2 mm diameter microfibre knot resonator sensing region. The proposed sensor has exhibited a linear spectral response with temperature and refractive index. A small change in free spectral range is observed when the microfibre device experiences a large refractive index change in the surrounding medium. The change is found to be in agreement with calculated results based on dispersion relationships

The Applications of FBG sensor for Realtime Strain Mapping of Thin Composite Plate under Point Loading

FBG sensor technology has shown as great potential for structural health monitoring applications in recent decades. The integration of this optical sensor into composite structures accelerates the development of robust smart structures. This paper presents the use of embedded FBG sensor to view the real-time strain mapping of a thin composite under a point loading. The FBG interrogation system implements the match-filter method to convert wavelength variations into strain reading. In was found that, the FBG sensor system was very sensitive for different loading variations and able to update the strain value in real-time. At the end of this research, a prototype of online strain mapping system for thin composite plate, utilizing an embedded FBG sensor, has been built

Investigation of dispersion characteristic in tapered fiber

A dispersion characteristic of a tapered fiber is investigated using temporal interferometer by employing a broadband amplified spontaneous emission (ASE) source to generate an interference pattern. The dispersion characteristic of the tapered fiber is acquired from a Fourier transform of the interference pattern. The second and third order dispersions of β2 and β3 are obtained at 1544.1 nm for -600 ps2/km and -2 ps3/km, respectively. The β2 value obtained is observed to be more than 300 times higher than that of a non-tapered single mode fiber. The high dispersion characteristic is due to tapering process that changes the birefringence characteristic due to the reduction in the fiber's size and structure

Microfiber structures for sensor applications

Microfiber loop resonator (MLR) and microfiber knot resonator (MKR) are fabricated using melt-stretching method for applications in temperature and current sensor, respectively. The MLR is embedded into low refractive index polymer for robustness. Although the spacing of the transmission comb spectrum of the MLR is unchanged with temperature, the extinction ratio of the spectrum is observed to decrease linearly with temperature due to induced changes in the material's refractive index. The slope of the extinction ratio reduction against temperature is about 0.043dB/°C. With the assistance of a copper wire that is wrapped by the MKR, resonant wavelength can be tuned by varying the electric current delivered to the wire. The resonant wavelength change is based on the thermally induced optical phase shift in the MKR due to the heat produced by the flow of electric current over a short transit length. It is shown that the wavelength shift is linearly proportional to the square of current in the copper wire with a tuning slope of 46 pm/A 2