Rahmat Mohsin

A study of the throughflow of nucleating steam in a turbine stage by a time-marching method

In the course of expansion in turbines, steam first supercools and then nucleates to become a two-phase mixture. The fluid then consists of a very large number of extremely small droplets which are carried by and interact with the parent vapour. The formation and subsequent behaviour of the liquid phase cause problems which lower the performance of the wet stages of steam turbines. To treat such flows the general conservation equations governing the whole field are combined with those describing droplet nucleation and growth and the set treated numerically. The article examines the solution of throughflows of nucleating steam in a turbine stage using a time-marching technique. The treatment which is the refinement of an earlier one has been applied to the flow in a turbine stage. Comparisons are presented between the results of theoretical solutions and direct measurements upstream and downstream of the nucleating stage and the agreement obtained is good.

Flow Pattern Map of Malaysian Crude Oil and Water Two-Phase Flow in a Pipe System

Water produced along with the crude oil during production and transported together in a pipeline is a common occurrence in a petroleum production system. Understanding the behavior of crude oil-water flow in a pipe is crucial to engineering applications such as design and operation of flow lines and wells, and separation systems. Presently, there was no two phase flow study done on the Malaysian waxy crude oil-water. Therefore, a research work was conducted at the Malaysia Petroleum Resources Corporation Institute for Oil and Gas, Universiti Teknologi Malaysia to study the flow pattern of the Malaysian waxy crude oil-water flowing in a closed-loop system at the ambient condition through a 5.08 cm ID stainless steel horizontal pipeline. The research works comprised fluid characterization and flow pattern observation using a video camera camcorder. Five flow patterns have been identified, namely stratified wavy flow, stratified wavy with semi dispersed flow at interface and oil film, dispersion of water in oil and oil continuous with emulsion, dispersion of oil in water with water continuous, and the newly found semi dispersed flow with semi emulsion at interface and thin oil film. The experimental results could be used as a platform to understand better a more complex case of gas, oil, and water flow in a pipeline, which is of utmost importance in designing optimum surface facilities.

Pressure drop and water holdup of Malaysian crude oil and water two-phase flow in pipes

Understanding the pressure drop and water holdup of crude oil-water flow in a pipe is crucial to many engineering applications. Free water in contact with the pipes wall can cause erosion or corrosion problems. An experimental research was conducted at the Malaysia Petroleum Resources Corporation Institute for Oil and Gas, Universiti Teknologi Malaysia to study the pressure drop and water holdup of the Malaysian waxy crude oil-water flowing in a closed-loop system at ambient condition through a 5.08 cm ID stainless steel horizontal pipeline. In the research work, water cuts were varied from 0 - 90% with mixture velocities ranging from 0.1 0.8 m/s. The research works comprised fluid characterization, pressure drop, and liquid holdup measurement.The investigations proved that pressure drop increased with flow rates, while the water holdup was found to have decreased slightly at higher water cuts due to the presence of emulsion in the crude oil a challenge when using a waxy crude oil in a two phase flow system. The experimental results can be used as a platform to understand better a more complex case of liquid-liquid two phase flow.

Assessment of Usage of Biofuel in Aviation Industry in Malaysia

The current scenario of greenhouse gasses emissions is witnessing major impetus as a result of the ever expanding transportation sector across the globe, of which the aviation sector has played a major role. The Malaysian transportation sector, specifically the aviation sector, has a poor record of high carbon emissions, inspite of its history of biofuel and sustainable fuel policy. However, researchers around the globe are now diverting their attention from the conventional fossil fuels to biofuels, because it is cheaper to produce, increases the efficiency of the aircrafts and also reduces the environmental threat fossil fuel emissions pose to the planet. Alternative fuels like bioethanol and biodiesels are increasingly used in aviation industry, as a direct consequence of the global targets set by the International Air Transport Association. In the present study, the possibility of increased biofuel by the aviation industry of Malaysia is analyzed with specific focus on the global initiatives taken for the same, as well as the past and current trends of Malaysias general biofuel production and consumption. It has been estimated that the use of alternative fuels in aviation industry could reduce the flight related greenhouse gas emission by approximately 60 to 80 %. The recent trials that have been conducted on the importance of biofuels in aviation industry have indicated that these fuels are technically feasible. In this respect, the European community in conjunction with private airline companies and major biofuels producers in their area have played a very prominent role in commercializing the use of biofuels in air transport. But in Malaysia to see biofuels as anything other than their consumption in the food and healthcare industry is still a debatable topic. By addressing these research gaps, this paper focuses on the possibility of manufacturing biofuel products at a commercial scale in Malaysia to be used in the aviation industry to power jet engines in commercial aviation and for reduced carbon emission for increased sustainability of the environment.

Comparative Study of Natural Gas Adsorption Isotherms on Koh and H3po4 Palm Kernel Shells Porous Activated Carbon

Sustainable energy of Natural Gas (NG) has been an increasingly valuable and advantageous fossil fuel as it produces a cleaner combustion, and efficient consumption. Compressed Natural Gas (CNG) storage method and its utilisation has caused several problems due to high cost of installation for extensive 25.86 MPa high- pressure bulky cylinder, internal cylinder corrosion, and the possibility of releasing an explosive compressed gas. Adsorb Natural Gas (ANG) storage as a new technology, where natural gas is adsorbed in a suitable adsorbent with high porosity to increase the volume of gas stored in the vessel at lower pressure 3.45 – 5.52 MPa is a promising alternative. The energy density stored in ANG storage system is greater than the CNG vessel at the same pressure. Solid sustainable material of Palm Kernel Shell (PKS) was treated chemically to obtain adsorbent media to determine its adsorption and desorption rate performance at certain pressure. The adsorbent obtained by treatment with KOH and H3PO4 labelled as PKS-ACB and PKS-ACA. Samples were characterised by SEM, BET, TGA and FTIR. The SEM, BET, TGA and FTIR results showed promising results. The adsorption rate of the first 20 minutes was 0.038 mmol/g.min for PKS-ACA and 0.034 mmol/g.min for PKS- ACB. The desorption rate of PKS-ACA and PKS-ACB was 643 mmol/g.min and 430 mmol/g.min. There was no gas residual left in the sorbent. Findings highlighted that sustainable solid waste materials of palm kernel shell are renewable; its surface property as natural gas adsorbent storage known as ANG.

Sulphur Dioxide and Oxygen Adsorption Isotherm Breakthrough Time on Surface Porous Palm Shell Activated Carbon

Sulphur dioxide (SO2) releases from various industries can affect the environment and human health. Activated carbon has been widely studied in gas and liquid adsorption due to its capability in filtration to remove organic materials and particulate matter. Palm kernel shell (PKS) is an agricultural by-product from palm-oil processing mills. PKS has been used as the based material for the production of activated carbon (AC). The research is aimed to produce AC derived from sustainable palm solid waste and to study the breakthrough time adsorption isotherm of SO2 and oxygen (O2) on the AC. In this study, palm kernel shell activated carbon (PKS-AC) was prepared via carbonisation, impregnation and activation. The dry PKS was carbonised at 700 °C for 2 h in a furnace and was then impregnated with ferric chloride hexahydrate (FECI3.6H2O) in 1 : 5 ratios (ferric chloride hexahydrate to PKS-char). The treated PKS-char was activated through microwave heating at 400 W power level and 6 min irradiation time. The prepared AC were characterised using Thermo-gravimetric analysis (TGA), Fourier transform infrared spectroscopy (FTIR), Scanning electron microscopy (SEM) and Nitrogen adsorption isotherm. Breakthrough adsorption of SO2 and O2 was investigated in a fixed-bed reactor. The results shows that the prepared AC produced 23 and 7.5 s breakthrough time for SO2 and O2 adsorption. In conclusion, AC that produced from agricultural waste via impregnation with ferric chloride and microwave induced can be a new promising method for the production of simple and good quality of AC.

Modelling of cadmium (II) uptake from aqueous solutions using treated rice husk: Fixed - Bed studies

Rice husk is an agricultural waste material obtained mainly from rice mills. Treated rice husk was evaluated as a sorbent for cadmium (II) ions removal from solutions by utilising fixed-bed adsorption mode. In this study, the influence of flow rate (3 and 9 mL/min), adsorbent heights of (0.9, 1.8 and 2.8 cm) and influent cadmium ions concentration of (5 and 20 mg/L) on the sorption capacity of the adsorbent in a fixed-bed column were explored. The highest uptake of 87 % was obtained using 20 mg/L initial Cd (II) solution was achieved at high flow rate of 9 mL/min and a bed height of 2.8 cm. The experimental results obtained from the column adsorption studies were correlated with the Thomas, Yoon–Nelson and Adams–Bohart models. The modelling results for the adsorption indicated that the Adams–Bohart model fitted well over the other models.

CO2 adsorption isotherms on KOH, H3PO4 and FeCl3.6H2O Impregnated palm shell kernel activated carbon

Commercial sorbents available are expensive as a result of using high cost and non-renewable materials as precursors. It is imperative to select cheap, viable and sustainable carbon source for production of adsorbents for subsequent use in adsorption applications. Palm kernel shell char was obtained by carbonisation process at 730 °C ± 20 °C for 2 h with 10 °C/min heating rate under inert gas flow. The bio-char obtained was further grinded and sieved to 0.5 to 0.85 mm, then treated and synthesised separately each sample by KOH, H3PO4 and FeCl3.6H2O solution with ratio 1 : 1 weight ratio and followed by microwave treatment technique. Samples treated with chemicals used were named as PKS-POT (Palm Kernel Shell with Potassium Hydroxide ), PKS- PAP (Palm Kernel Shell with Phosphoric acid) and PKS-FER(Palm Kernel Shell with Ferric chloride hexahydrate). CO2 gas was used during the adsorption and desorption study. Samples were characterised by Brunauer–Emmett–Teller (BET), scanning electron microscope (SEM) and Fourier transform infraredspectroscopy (FTIR). PKS-POT showed highest BET surface area (208.7037 m2/g) and pore volume (0.06580 cm3/g). PKS-POT’s SEM result also confirms large surface area, pores and more compact of the shell structure which related to high adsorption capacity compared to PKS-PAP and PKS-FER. CO2 PKS-POT, PKS-PAP and PKS-FER adsorption capacities were 2.19, 0.62 and 1.25 mmol/g and no CO2 gas left for the end desorption phase. From the study concluded that sustainable palm kernel shell material was successfully achieved to obtain the high surface area, high porosity and high adsorption sorbent capacity.

Phenolic Rich Components Identification of Heavy Oil Fractions of Biomass Pyrolytic Oil for Epoxy Resin Binder

Identification and assessment of phenol and phenolic rich components of heavy oil fractions of biomass pyrolytic oil were conducted. The original bio-oil used for this study was derived from the pyrolysis of empty fruit bunch (EFB). It was separated into water soluble (light oil) and water insoluble (heavy oil) components by mixing it with water at 2:1 V/V ratio under ambient condition with vigorous stirring using centrifuge for 30mins. The raw bio-oil and the heavy oil fractions were later characterized using Fourier Transform Infra-Red (FTIR) and Gas chromatography-Mass spectroscopy (GC-MS) techniques in order to identify the function groups present and their compositions. The GC-MS results for the heavy oil indicated a high concentration of phenol and phenolic components, which was strongly supported by the presence of OH group (characteristic of phenol) from FTIR analysis. Utilization of bio-oil which was known to have a significant amount of phenol and phenolic rich components for phenolic, novolac or epoxy resin manufacture would significantly reduce the cost and negative environmental effects of the fossil-based resins.

Preparation of Epoxy-Novolac Resin Binder Using Phenolic Rich Fractions of Biomass Pyrolytic Oil as Partial Substitute of Phenol

Epoxy resins are among the basic components for coatings manufacture but because of their cost and environment effects, some environmental protection regulations have restricted the use of chemicals considered toxic. The potential of using phenolic rich fractions of bio-oil derived from the pyrolysis of a sustainable agricultural waste for epoxy resin synthesis was investigated. Epoxy resins with different concentration of water-insoluble heavy fraction were synthesized. The bio-oil, heavy fraction and prepared resins were later characterized using Fourier Transform Infra-Red (FTIR), Gas Chromatography Mass Spectrometry (GC-MS) and Differential Scanning Calorimetry (DSC). FTIR and GC-MS results confirmed the presence of phenols on both the bio-oil and heavy fraction with heavy fraction having a higher concentration. DSC analysis showed a corresponding increase on curing time of the resins with increased quantity of phenolic rich components. FTIR analysis of the resin indicated high-ortho structure. Utilization of bio-oil as a source of phenol for epoxy resins manufacture would significantly reduce the cost and negative environmental effects of the current resins.