Advanced Materials Research Vol. 1113

Abstract: This paper discusses the effect of reaction time and temperature of silver-copper nanoparticles prepared by a polyol method. In this study, silver-copper nanoparticles were synthesized through the green approach of polyol method using ethylene glycol (EG) as green solvent and reductant, and polyoxyethylene-(80)-sorbitan monooleate (Tween 80) as a nontoxic stabilizer. The phase and morphology of silver-copper nanoparticles were characterized by X-ray diffraction (XRD) and Field emission scanning electron microscope (FESEM). The results XRD confirmed silver and copper nanoparticles to be phase-pure crystalline silver and copper with face-centered cubic (fcc) structure on the basis of XRD analyses. FESEM analysis confirmed the existence of Ag and Cu nanoparticles.

Abstract: The thermal property of new composition of eutectic molten salt was investigated to obtain low melting point and better stability at temperature of 500°C as heat transfer fluid in solar thermal energy system. The NaCl used was purified from seawater. The eutectic molten salts were prepared in ten different weight ratios and experiments were carried out using nitrogen as inert gas with heating of 10°C/min to the temperature from 25°C to 500°C. Experimental results indicated that all mixtures exhibited low melting point (<163°C) and high stability. The thermal degradation of LiNO₃, NaNO₃, KNO₃ and NaCl exhibit in the DTG profiles respectively. From the present study it can be concluded that major weight loss of the system is due to the dissociation of lithium nitrate to lithium oxides.

Abstract: Shale gas nowadays is an important source of unconventional gas. The limited conventional gas supply makes the unconventional sources as a new source of gas. In this research, the aim is to design a mud formulation that can carry out essential functions of mud for shale gas drilling. Commonly for shale gas drilling, water based mud is used. However, water based mud is ineffective when dealing with water-sensitive shale. The alternative way to deal with this type of shale is using synthetic-based mud (SBM) or oil-based mud (OBM). OBM is an effective mud while drilling well. However, it is toxic and gives negative impact to environment. SBM somehow is more environmental friendly compared to oil based and ester is one of the synthetic based fluids. In order to prove this statement, a toxicity test was carried out to investigate the impact of ester based mud on selected marine life. The results of the test were compared with past research results. The ester use in this research is methyl-ester C12-C14 derived from palm oil and the mud was formulated at different oil-water ratios which are 70/30, 80/20 and 90/10, respectively and the best rheological performance can be seen at 80/20 oil-water ratio. Then, the performance of this mud had been compared to other types of mud which are sarapar-based and WBM. The findings revealed that the rheological performance of ester based mud is comparable with common based mud used for shale gas drilling. Apart from that, it is less toxic than other based mud which can maintain 60% prawn’s survival even after 96 hours exposure in 100,000 ppm of mud concentration in artificial seawater.

Abstract: Hydrogen is one of the most abundant elements in the universe and a clean carrier of energy. However, the existence of hydrogen is in different compound forms, in which a great deal of energy is required to split from the compounds. Gasification of biomass is one of the best methods to produce hydrogen. This study focuses on the production of hydrogen in gasification process by using a throated downdraft gasifier and preheated air as gasifying agent. For the study on the effect of gasifying air temperature on hydrogen concentration in the syngas an electric heater was used to preheat the inlet air up to 500°C. The results of the study showed that increasing the gasifying air temperature from 30°C to 500°C increased the volume concentration of hydrogen by 25.1% in the syngas. The increase in hydrogen was steeper when the inlet air was in the lower range temperature (30 to 265°C) as compared to that of the upper range (265 to 500°C).

Abstract: Kenaf fiber has been recognised as a new material for adsorption based on its porous structure. However, previous studies have proved that modified kenaf could give better interaction towards adsorbates than the raw kenaf during the adsorption. In this study, kenaf core fiber has been modified using Nickel metal (Ni-metal). Different concentration of Nickel nitrate, Ni(NO₃)₂ (0.01 M and 1 M) have been used to observe the effect of Ni-metal for hydrogen adsorption. Initially, raw kenaf sample has been grinded and sieved into 500 µm in size. Then, the sample was heated to remove the moisture and Ni(NO₃)₂ has been added into the dried kenaf. Based on this study, modified kenaf with 0.1 M Ni(NO₃)₂ and 1 M Ni(NO₃)₂ has adsorbed more hydrogen compared to the raw kenaf. The result has provided a fundamental knowledge of kenaf as hydrogen storage material.

Abstract: Foam Flooding have been suggested to replace gas injection in Enhanced Oil Recovery (EOR) method since it will improve the volumetric sweep efficiency due to its low mobility. This paper aims to review on the relationship of Interfacial Tension (IFT) of the CO₂ foams and nanoparticle surface modification. Generally, in foam flooding technique, surfactant is used to stabilize the CO₂ foams. However, the concern about the stability of the surfactant-stabilized CO₂ foam has been rising due to high surfactant adsorption on the rock surface and they also tend to degrade at high temperature. Hence, nanoparticle has been introduced to generate more stable CO₂ foam by adsorption of nanoparticles at the fluid-fluid interface. Based on the review, the stability of CO₂ foam generated by nanoparticles is due to the strong adhesion energy at the fluid-fluid interface where the interfacial tension between aqueous phase and CO₂ gas phase inside the foam is one of the key parameter. It also has been identified that the main factors that influenced the interfacial tension at the fluid-fluid interface are the nanoparticles concentration and the degree of hydrophilicity of nanoparticles. The correct amount of nanosolid particles present at the fluid-fluid interface and the optimum degree of hydrophilicity with favorable contact angles less than 90 degree will increase the interfacial tension that lead to increase in adhesion energy and high stability foam can be generated.

Abstract: This article is an overview of potential application of wettability modifier to enhance oil recovery in carbonate reservoir. In oil and gas industry, oil recovery can be divided into three stages which are primary recovery, secondary recovery and tertiary recovery. The primary recovery is the initial stages of oil recovery. At this stage, oil was displaced toward production well by natural drive mechanisms that naturally exist in the reservoir. Water is commonly used to enhance oil recovery by injected into the reservoir because of it is commercially available, less expensive and capable to maintain the reservoir pressure. In conclusion, smart water flooding is a new technique to solve the complexity problem of carbonate reservoir by manipulating the salinity and ionic composition in high temperature. Hence, smart water can be an excellent candidate as a displacing fluid in chemical flooding for enhanced the oil recovery (EOR).

Abstract: When drill in a highly permeable zone the common problem faced by the operator is lost circulation of drilling mud into the formation. Lost circulation of mud are costly and therefore lost circulation materials (LCM) being introduced to the mud formulation to prevent lost circulation from the formation. Since Malaysia is the one of the major country producer of Palm kernel Oil (PKO) with the high production of crude fibre from palm kernel (palm kernel expeller), thus this study was carried out to determine the ability of Palm Kernel Expeller (PKE) to be used as LCM in drilling mud. PKE used was in granule form by cause of pressing under high pressure compress to remove palm oil. Rheological and API filtration test were carried to determine the characteristic PKE in drilling mud. Water based mud (WBM) sample was used in this study with four (4) different concentration of PKE. The results show the filter cake formed was improved as the concentration increased and the filtrate loss reduced. SEM data also shows the ability of PKE to form a bridge across the pore thus reducing the loss of filtration.

Abstract: The need to find a renewable and sustainable energy has transformed into a demand due to the depletion of fossil fuel, and more importantly, the greenhouse gasses concerns. Hydrogen is a one of the clean and sustainable energy source. In addition, hydrogen used as raw material in industries, such as fertilizer plant, refinery and methanol production plant. Hydrogen has the potential as a clean energy carrier and the date pits availability in Saudi Arabia, the gasification of date pits is proposed. This work focused on developing a flowsheet to evaluate the feasibility of producing hydrogen from the gasification of date pits via a simulation work in Aspen Hysys. Using the simulation model, a study has been made to investigate the effects of temperature and steam/biomass ratio on the product gas, hydrogen yield and carbon conversion. The model has been also validated with literature and showed good agreement. The favorable temperature of the gasifier for high hydrogen yield is predicted to be in the range of 845-910°C. Based on the results, at temperature is 850°C and steam/biomass ratio of 0.8, maximum conversion and hydrogen yield achieved.

Abstract: Membrane technology in gas separation application was commercialized approximately 30 years ago because of a number of advantages offered compare to the conventional technique. The use of poly (lactic acid) (PLA), a biodegradable polymer, as a membrane material would assist the reduction of depending to petroleum-based polymer. This study investigated the effect of evaporation time to the gas separation performance of PLA membrane. Membrane prepared from polymer solution consist of PLA and dicholoremethane (DCM) as solvent was fabricated using pneumatically controlled casting system with dry/wet phase inversion method. Permeation test was conducted using pure carbon dioxide and methane gas. The results revealed that as the evaporation time increased, the pore size and surface porosity decreased, while the skin layer thickness increased. Although the morphology of the prepared membranes showed the desirable structure, the gas separation performance of the membrane prepared with polymer concentration of 15wt% and 60s evaporation time was found to be promising but not yet commercially ready.