Showing papers by "Universiti Teknologi Petronas published in 2016"
TL;DR: In this article, a detailed discussion to produce biodiesel, fuel gas, bio-oil, methane, hydrogen and alcohol from microalgae biomass are also included, along with updated research, challenges and the way forward of micro-algae biofuels are also presented.
Abstract: Biofuels productions from microalgae received wide attention recently and have high potential to replace fossil fuels. This paper served as a platform to critically review current production technologies of microalgae, ranging from cultivation, harvesting, extraction and several biofuels conversion processes. In addition, due to the high photosynthetic efficiency of microalgae, mass cultivation of microalgae is believed to be able to efficiently reduce the carbon dioxide emission to atmosphere and thus, reducing the impact of global warming. This is because microalgae have high growth rate and is able to develop maximum of 70% of lipid content within their cells depending on species. Apart from that, microalgae have the ability to survive under harsh condition and occupied smaller cultivation land area than other land crops. The harvested microalgae biomass can be used for electrical generation, while its crude lipid can be used as transportation fuel as it has 80% average energy content of petroleum. In the present paper, a detailed discussion to produce biodiesel, fuel gas, bio-oil, methane, hydrogen and alcohol from microalgae biomass are also included. Besides, updated research, challenges and the way forward of microalgae biofuels are also presented. In future, biofuels production from microalgae can be economical viable at some scale, which is then profitable in terms of economics and also environment.
446 citations
TL;DR: In this paper, the characteristics and performances of different types of gasifiers under variable process parameters that will affect the yields of the end products as well as the composition of the gas.
Abstract: Currently, the use of biomass as an energy source has received a tremendous amount of interest from all over the world due to its advantage in providing a continuous feedstock supply. Moreover, when compared to fossil fuels, biomass fuels possess negligible sulfur concentrations, produce less ash, and generate far less emissions into the air. Biomass has a potential to be a very promising alternative source of raw material for syngas production due to its tremendous availability. Syngas can be produced from the gasification of a biomass. However, this process requires a significant amount of energy due to the endothermic behavior of the reaction. The energy consumption during the gasification process is a major constraint on the thermal efficiency and on the design of the gasifier. Therefore, a substantial improvement and the optimization of the available gasification process are very crucial in developing a sustainable utilization of these renewable natural resources. This review article focuses on highlighting the characteristics and performances of the different types of gasifiers under variable process parameters that will affect the yields of the end products as well as the composition of the gas. The various types of models used in the simulations, the optimization of the gasification conditions and the economic evaluation of the gasification process will also be discussed.
359 citations
TL;DR: The aim of the current review is to develop technical understanding of the conventional and non-conventional coating materials and associated spray coating mechanism for slow release urea production and the potential of starch as the coating material in relation to the coatings tested previously for controlled release fertilizers.
329 citations
TL;DR: In this paper, the literature bearing on the use of optimization methods for charging infrastructure is considered, and the authors present a review study of the literature related to the optimization of EV charging infrastructure.
Abstract: For the consideration of environmental aspects of the personal transportation, electric vehicle (EV) and plug-in hybrid electric vehicle (PHEV) has the prospective solution nonetheless there is an obstacle to access the charging system plug. Additionally, the charging system delivers its own troubles when we compared it with petrol station since the participation of the different charging alternative. For the last few years, the studies associated with optimization of PHEV/EV charging infrastructure have drawn the researcher׳s consideration. New challenges and chances for the growth of smart grid technologies depend upon the recently introduced electric vehicle charging infrastructure services. In this particular review study, the literature bearing on the use of optimization methods for charging infrastructure is considered.
274 citations
TL;DR: It is strongly believed that IL-compatible cellulase systems would eliminate the need to recover the regenerated biomass and lead to a simple, in situ saccharification of cellulosic materials, which would be beneficial in developing integrated bioprocesses.
274 citations
TL;DR: In this article, the role and performances of activated carbon in capturing anthropogenic CO2 flue gas prior to emission to air were reviewed and evaluated in terms of equilibrium adsorption capacity as well as the surface modification.
Abstract: The increase of carbon dioxide (CO2) concentration in the ambient air has become the key factor in the pace of temperature rise, and accordingly, is a primary contributor towards global warming scenario. In view of this, the quick mitigation efforts associated with capturing CO2 from fossil fuel combustion source must be implemented to alleviate environmental catastrophic events in future. Therefore, the purpose of this paper was to review the role and performances of activated carbon in capturing anthropogenic CO2 flue gas prior to emission to air. Throughout this paper, the activated carbons which were proposed to be a separation medium for CO2 capture are evaluated in terms of equilibrium adsorption capacity as well as the surface modification. The utilization of the activated carbons instead of current state-of-art technology, which is the chemical absorption is promising as it avoids higher energy penalty encountered in regeneration process and the consumption of corrosive chemical such as aqueous amine-based solvent. In addition, the investigation on the potential of activated carbons for post-combustion CO2 capture is expected to confer scientists with critical information related to the future direction of the activated carbons in an industrial application, and as an alternative to conventional amine scrubbing process.
259 citations
TL;DR: In this paper, a comprehensive review on the research progress on the enhancement of effective thermal conductivity and effective dynamic viscosity of nanofluids is presented, with the consideration of particle size valid in their experimental range.
Abstract: The determination of thermo-physical properties and especially thermal conductivity and viscosity were important for evaluating heat transfer coefficients either for single or two phase flow. The thermo-physical properties measurements and heat transfer observations were mostly obtained with nanoparticles above 10 nm. Various researchers measured and modelled for the determination of thermal conductivity and viscosity of nanofluids. Most of the investigators developed equations for the estimation of thermal conductivity and viscosity as a function of percentage volume concentration, temperature and sometimes with the consideration of particle size valid in their experimental range. Nanofluids are considered to have great potential for heat transfer enhancement and are applied in heat transfer processes. Many studies were carried out to investigate this phenomenon. The main aim of this study is to give a comprehensive review on the research progress on the enhancement of effective thermal conductivity and effective dynamic viscosity of nanofluids.
245 citations
TL;DR: A range of numerous corrosion inhibitors, viz. organic molecules with hetero atoms and π-electron clouds, inorganic salts and plant excerpts likewise their corresponding phytoconstituents were reported with success for metals in different corrosive media as discussed by the authors.
Abstract: A range of numerous corrosion inhibitors, viz. organic molecules with hetero atoms and π-electron clouds, inorganic salts and plant excerpts likewise their corresponding phytoconstituents were reported with success for metals in different corrosive media. Various literature reviews related to corrosion inhibitors have been reported by many authors based on their application, classification, and inhibition mechanism. A short view of all these reviews is summarized in this manuscript. Various aspects of corrosion inhibitors as well as their recent trends and advancement are also discussed.
213 citations
TL;DR: The efforts made in using ILs in drug solubility, API formulation and drug delivery, including topical, transdermal and oral delivery, are presented, with particular emphasis on recent developments.
Abstract: The pharmaceutical industries face a series of challenges in the delivery of many newly developed drug molecules because of their low solubility, bioavailability, stability and polymorphic conversion. These limitations are further exacerbated when drug molecules are insoluble or sparingly soluble in water and most pharmaceutically accepted organic solvents. To address these limitations, innovation is required in the pharmaceutical sciences for the formulation of drugs, solvents or systems for effective drug delivery. Fortunately, in the past few years, ionic liquids (ILs)—a novel class of environmentally benign and tailor-made solvents—have been increasingly exploited as solvents, co-solvents and/or materials in the fields of pharmaceutical drug delivery and active pharmaceutical ingredient (API) formulation because of their unique and tunable physicochemical and biological properties. The use of ILs can markedly improve the pharmacokinetic and pharmacodynamic properties of drugs. To highlight the potential of ILs as a drug delivery/formulation tool, this review gives an overview of the application of ILs to address critical pharmaceutical challenges, including the low solubility, polymorphism and bioavailability of drugs. This review is not intended to be comprehensive, but rather to present the efforts made in using ILs in drug solubility, API formulation and drug delivery, including topical, transdermal and oral delivery, with particular emphasis on recent developments.
196 citations
TL;DR: In this paper, 20-nm nano copper nanoparticles were dispersed into paraffin wax to synthesize Cu-PCM nanocomposites, and five samples have been prepared to investigate the thermal properties of the produced Cu -PCM nano-composites.
190 citations
TL;DR: In this article, the authors presented a full analysis of Artificial Intelligence optimum plans in the literature, making the contribution of penetrating extensively the renewable energy aspects for improving the functioning of the systems economically.
Abstract: Consciousness of the need to decrease our unnatural weather changes and of the critical increase in the costs of traditional sources of energy have motivated many nations to provide innovative energy strategies that promulgate renewable energy systems. For example, solar, wind and hydro related energies are renewable energy sources, and they are environmentally friendly with the potential for broad use. All of the load requirement conditions in comparison with single usage can provide more economical and dependable electricity, as well as environmentally friendly sources, by compounding such renewable energy sources using backup units to shape a hybrid scheme. Sizing the hybrid system elements optimally is one of the most important matters in this type of hybrid system, which could sufficiently meet all of the load demands with a minor financial investment. Although a number of studies have been performed on the optimization and sizing of hybrid renewable energy systems, this study presents a full analysis of Artificial Intelligence optimum plans in the literature, making the contribution of penetrating extensively the renewable energy aspects for improving the functioning of the systems economically.
TL;DR: This study suggests that combination of EEG (frontal alpha rhythm) and fNIRS (concentration change of oxygenated hemoglobin) could be a potential means to assess mental stress objectively.
Abstract: Previous studies reported mental stress as one of the major contributing factors leading to various diseases such as heart attack, depression and stroke. An accurate stress assessment method may thus be of importance to clinical intervention and disease prevention. We propose a joint independent component analysis (jICA) based approach to fuse simultaneous measurement of electroencephalography (EEG) and functional near-infrared spectroscopy (fNIRS) on the prefrontal cortex (PFC) as a means of stress assessment. For the purpose of this study, stress was induced by using an established mental arithmetic task under time pressure with negative feedback. The induction of mental stress was confirmed by salivary alpha amylase test. Experiment results showed that the proposed fusion of EEG and fNIRS measurements improves the classification accuracy of mental stress by +3.4% compared to EEG alone and +11% compared to fNIRS alone. Similar improvements were also observed in sensitivity and specificity of proposed approach over unimodal EEG/fNIRS. Our study suggests that combination of EEG (frontal alpha rhythm) and fNIRS (concentration change of oxygenated hemoglobin) could be a potential means to assess mental stress objectively.
TL;DR: In this article, a common amino acid, l -arginine (0.05, 0.10,0.15 and 0.20 ) was added to (Choline chloride+urea) to form ternary deep eutectic solvents, and the physical properties such as density, viscosity and refractive index were measured.
TL;DR: Due to sterically-hindered adsorption of some thiophenic sulfur compounds (S-compounds) such as thiophene, dibenzothiophene and their derivatives on catalyst surface, hydrodesulfurization (HDS) is not effective to remove such S-compound in fuel oils as mentioned in this paper.
Abstract: Due to sterically-hindered adsorption of some thiophenic sulfur compounds (S-compounds) such as thiophene, dibenzothiophene and their derivatives on catalyst surface, hydrodesulfurization (HDS) is not effective to remove such thiophenic S-compounds in fuel oils. To produce clean fuel oils with lower S-content (e.g., S
TL;DR: In this paper, a unified model for thermal conductivity and viscosity of composite nanofluids is presented, based on reliable models for thermophysical properties such as density and specific heat.
Abstract: The limitation of the conventional fluids to facilitate cooling/heating rates remains the primary basis for exploring alternative heat transfer nanofluids. Research efforts on nanofluids have evolved over the past two decades in establishing extensive literature. Several models for thermophysical properties were made available to characterize the behaviors of diverse individual nanofluids. However, lack of reasonable agreement between theory and experimental results has been a limiting factor for the development of a unified nanofluid model for thermal conductivity. Existing models for thermo-physical properties of nanofluids such as density, specific heat, thermal conductivity, and viscosity are critically surveyed and appropriate equations are extended for composite nanofluids. Consequently, based on reliable models identified predictions for thermal conductivity and viscosity for composite nanofluids are presented. Overall results show that existing thermophysical models for density and specific heat are valid for all water based oxide nanofluids for both single material and composites whereas models for thermal conductivity and viscosity show selective response but have the versatility for predicting the behavior of single and composite nanofluids within acceptable deviation.
TL;DR: This article reviews the recent technological developments of ILs in protein‐, enzyme‐, and DNA‐based applications and discusses the different routes to increase biomolecule stability and activity in ILs, and the design of biomolecular‐friendly ILs that can dissolve biomolecules with minimum alteration to their structure.
Abstract: The technological utility of biomolecules (e.g. proteins, enzymes and DNA) can be significantly enhanced by combining them with ionic liquids (ILs) - potentially attractive "green" and "designer" solvents - rather than using in conventional organic solvents or water. In recent years, ILs have been used as solvents, cosolvents, and reagents for biocatalysis, biotransformation, protein preservation and stabilization, DNA solubilization and stabilization, and other biomolecule-based applications. Using ILs can dramatically enhance the structural and chemical stability of proteins, DNA, and enzymes. This article reviews the recent technological developments of ILs in protein-, enzyme-, and DNA-based applications. We discuss the different routes to increase biomolecule stability and activity in ILs, and the design of biomolecule-friendly ILs that can dissolve biomolecules with minimum alteration to their structure. This information will be helpful to design IL-based processes in biotechnology and the biological sciences that can serve as novel and selective processes for enzymatic reactions, protein and DNA stability, and other biomolecule-based applications.
01 Mar 2016
TL;DR: In this paper, the authors provide an overview of the palm oil industry, review technologies available to process oil palm and palm oil residues into biofuel, and summarise the challenges that should be overcome for further development.
Abstract: Over the last decades, the palm oil industry has been growing rapidly due to increasing demands for food, cosmetic, and hygienic products. Aside from producing palm oil, the industry generates a huge quantity of residues (dry and wet) which can be processed to produce biofuel. Driven by the necessity to find an alternative and renewable energy/fuel resources, numerous technologies have been developed and more are being developed to process oil-palm and palm-oil wastes into biofuel. To further develop these technologies, it is essential to understand the current stage of the industry and technology developments. The objective of this paper is to provide an overview of the palm oil industry, review technologies available to process oil palm and palm oil residues into biofuel, and to summarise the challenges that should be overcome for further development. The paper also discusses the research and development needs, technoeconomics, and life cycle analysis of biofuel production from oil-palm and palm-oil wastes.
TL;DR: Different medicinal plants and their active compounds, as well as green-synthesized metallic nanoparticles from medicinal plants, are discussed in relation to their anticancer activities.
Abstract: Cancer is a leading cause of death worldwide. Several classes of drugs are available to treat different types of cancer. Currently, researchers are paying significant attention to the development of drugs at the nanoscale level to increase their target specificity and to reduce their concentrations. Nanotechnology is a promising and growing field with multiple subdisciplines, such as nanostructures, nanomaterials, and nanoparticles. These materials have gained prominence in science due to their size, shape, and potential efficacy. Nanomedicine is an important field involving the use of various types of nanoparticles to treat cancer and cancerous cells. Synthesis of nanoparticles targeting biological pathways has become tremendously prominent due to the higher efficacy and fewer side effects of nanodrugs compared to other commercial cancer drugs. In this review, different medicinal plants and their active compounds, as well as green-synthesized metallic nanoparticles from medicinal plants, are discussed in relation to their anticancer activities.
TL;DR: In this paper, the authors studied the catalytic properties of the Ni and Co catalysts for vapor phase hydrodeoxygenation of guaiacol, a typical lignin-derived phenolic compound.
Abstract: Vapor-phase hydrodeoxygenation (HDO) of guaiacol, a typical lignin-derived phenolic compound, was studied on Al-MCM-41 supported Ni and Co catalysts at 400 °C and atmospheric pressure. Ni was found as an active metal for ring opening activity while Co favored the deoxygenation activity. Besides benzene and phenol were observed as the major deoxygenation products, the existence of toluene, cresol and other methylated C 7–12 products was the result of methyl transfer reaction over the acidic function of support. Co/Al-MCM-41 catalyzed not only HDO to remove oxygen but also transalkylation to prevent the carbon loss via methanization. In addition, coke deposit mainly gathered on the surrounding area of cobalt particles, leading to the faster deactivation in HDO activity than transalykation.
TL;DR: In this paper, the authors highlighted the potential of hydrodynamic cavitation for the methyl ester production from waste cooking oil and showed that the high turbulence generated by the cavitating bubbles were effective in reducing the mass transfer resistance between immiscible reactants during the transesterification reaction due to increased interfacial area.
TL;DR: This study explores the potential of producing biodiesel using lipids from H. illucens larvae and finds FAME derived from larvae lipids is feasible to be used for biodiesel production.
TL;DR: This paper addresses the problem of automatic classification of Spectral Domain OCT (SD-OCT) data for automatic identification of patients with DME versus normal subjects by proposing a classification framework with five distinctive steps and presenting an extensive study of each step.
Abstract: This paper addresses the problem of automatic classification of Spectral Domain OCT (SD-OCT) data for automatic identification of patients with DME versus normal subjects. Optical Coherence Tomography (OCT) has been a valuable diagnostic tool for DME, which is among the most common causes of irreversible vision loss in individuals with diabetes. Here, a classification framework with five distinctive steps is proposed and we present an extensive study of each step. Our method considers combination of various preprocessing steps in conjunction with Local Binary Patterns (LBP) features and different mapping strategies. Using linear and nonlinear classifiers, we tested the developed framework on a balanced cohort of 32 patients. Experimental results show that the proposed method outperforms the previous studies by achieving a Sensitivity (SE) and a Specificity (SP) of 81.2% and 93.7%, respectively. Our study concludes that the 3D features and high-level representation of 2D features using patches achieve the best results. However, the effects of preprocessing are inconsistent with different classifiers and feature configurations.
TL;DR: In this article, the effect of NaOH concentration on the properties of fly ash-based geopolymer matrixes was analyzed using Fourier Transform Infrared Spectroscopy (FTIR) for structural elucidation, Scanning Electron Microscope (SEM) to observe the morphology and determination of the mechanical properties (flexural strength).
TL;DR: In this paper, the authors investigated the effect of the NaOH solution molarity and Na 2 SiO 3 /NaOH ratio on the physical and mechanical properties of high calcium fly ash based geopolymers.
TL;DR: In this article, a review discusses several potential strategies for tackling the environmental problems generated by POME together with renewable energies production, such as biomethane and biohydrogen.
Abstract: Sustainable and cost effective ways to produce renewable energy from biomass have generated considerable interest. Palm oil industries generates huge amount of waste. From one tonne of processed fresh fruit bunches (FFB), different types of wastes are generated which includes empty fruit bunch (EFB) (23%), mesocarp fiber (12%), shell (5%) and palm oil mill effluent (POME) (60%). POME has a high chemical and biochemical oxygen demand and mineral content such as nitrogen and phosphorous which can cause severe pollution to the environment. This can be a great nutrient for algal cultivation whilst remediating effluent and generating biomethane through anaerobic digestion. Algae capable of producing lipids and hydrocarbons with their photosynthetic abilities are among potential candidates for bioenergy generation. The harvested microalgal biomass can be used to produce bioethanol through fermentation. An integrated wastewater treatment and renewable bioenergy production would be an added benefit to the oil palm industry. This review discusses several potential strategies for tackling the environmental problems generated by POME together with renewable energies production, such as biomethane and biohydrogen. In addition, the prospects and technologies for commercialization of those renewable energies are discussed in detail. Apart from that, co-cultivation of microalgae using POME for biodiesel, bioethanol and biomethane production together with wastewater treatments are suggested as a new process for the enhancement renewable energies generation from oil palm mills. This unrealistic approach will ultimately become an essential standard reference for scientists, oil palm millers and government stakeholders.
TL;DR: In this article, seven non-edible oils have been selected, which include waste cooking oil derived palm olein, Calophyllum inophyllUM, jatropha oil, castor oil, rubber seed oil, kapok seed oil and karanja oil The critical parameters, eg cetane number (CN), iodine value (IV) and oxidation stability (OS) of biodiesel were correlated with the degree of unsaturated (DU) fatty acid, whereas the cold filter plugging point (CFPP) was correlated with long chain saturated factor (
Abstract: Physical and chemical properties of biodiesel are influenced by the structural features of fatty acid, such as with saturated, monounsaturated and polyunsaturated fatty acids In this study, seven non-edible oils have been selected, which include waste cooking oil derived palm olein, Calophyllum inophyllum, jatropha oil, castor oil, rubber seed oil, kapok seed oil and karanja oil The critical parameters, eg cetane number (CN), iodine value (IV) and oxidation stability (OS) of biodiesel were correlated with the degree of unsaturated (DU) fatty acid, whereas the cold filter plugging point (CFPP) was correlated with the long chain saturated factor (LCSF) To meet the minimum EU requirement of EN 14214 of the critical parameter, the DU value of the CN was ≤1335, IV ≤1232 and OS ≤989 The LCSF values satisfied the Spanish regional standard—RD 61/2006 in summer (0 °C) at ≤84 and winter (−10 °C) at ≤01 of the CFPP Based on the composition of the saturated, monounsaturated and polyunsaturated fatty acids, a triangular chart for the biodiesel property prediction was developed This can then be used as a reference for non-edible oils
TL;DR: In the early stage of membrane technology development in gas separation, utilization of polymeric membranes has gained attention due to their robustness and ease of fabrication as discussed by the authors, however, the performance is limited by the trade-off between permeability and selectivity.
Abstract: In the early stage of membrane technology development in gas separation, utilization of polymeric membranes has gained attention due to their robustness and ease of fabrication. However, the performance of polymeric membranes is limited by the trade-off between permeability and selectivity. Meanwhile, inorganic membrane is capable to exhibit great enhancement in separation performance but unfortunately its fabrication process is hard and costly. Thus, development of mixed matrix membranes (MMMs) by incorporating inorganic fillers into the polymer matrix has become a potential alternative to overcome the limitations of polymeric and inorganic membranes in gas separation. Nevertheless, fabrication of defect-free MMMs with improved separation performance and without compromising the mechanical and thermal stability is extremely difficult and challenging. In the current review paper, various types of inorganic fillers for MMMs fabrication and recent reported efforts to tailor the underlying problems on MMMs f...
TL;DR: In this article, commercial Norit® SX2 activated carbon has been evaluated as a solid adsorbent for carbon dioxide (CO 2 ) capture at the post-combustion conditions, which are at an ambient pressure and low temperatures ( o C).
TL;DR: In this article, the performance of benign solvents, namely deep eutectic solutions (DES), in the separation of aromatic-aliphatic hydrocarbon azeotropic mixtures via liquid-liquid extraction (LLE) was evaluated.
Abstract: The efficient and sustainable separation of azeotropic mixtures remains a challenge in chemical engineering. In this work, the performance of benign solvents, namely deep eutectic solvents (DES), in the separation of aromatic–aliphatic hydrocarbon azeotropic mixtures via liquid–liquid extraction (LLE) was evaluated. The DES studied in this work were based on different ammonium salts (cholinium chloride, [Ch]Cl, benzylcholinium chloride, [BzCh]Cl, and tetrabutylammonium chloride, [N4444]Cl) as hydrogen bond acceptor (HBA) and one organic acid (levulinic acid, LevA) as hydrogen bond donor (HBD), always in the mole ratio of 1 HBA:2 HBD. The thermophysical properties, namely density and viscosity, of the three used DES were measured in the temperature range T = (293.15 up to 353.15) K and at atmospheric pressure. The phase equilibria diagrams of all ternary systems were determined at T = 298.15 K and at atmospheric pressure using 1H NMR spectroscopy. The results showed that the introduction of a more hydropho...