Faisal Abnisa | University of Malaya, Malaysia (original) (raw)

Papers by Faisal Abnisa

Journal of environmental chemical engineering, Aug 1, 2021

This study comparatively investigates the catalytic activities and degradation kinetics of the pr... more This study comparatively investigates the catalytic activities and degradation kinetics of the produced biodiesels using kaolinite-based heterogeneous catalysts to examine the stability. The performance of the catalysts was tested under the same operating parameter (methanol/oil ratio, 5:1, at 200 • C for 6 h). The obtained biodiesel was analyzed using TGA equipment to obtain the yield, as well as the degradation kinetic parameters. It was observed that the solid superacid SHY zeolite gave the highest biodiesel yield (90.76%) because of higher acid strength. The catalysts performance is in the order of HY<ALK<HLK<NaLK<SHY zeolite. The lower performance of HY (72.42% yield) is attributed to the presence of high basic sites, being that shea butter has high FFA. The degradation kinetics of each biodiesel sample was performed using the TGA data to examine the thermal and oxidative stability. The frequency factor (A), activation energy, and reaction order were determined by employing the Coats-Redfern model. It was observed that first-order reaction mechanism can satisfactorily describe all the biodiesel kinetics. Further, the biodiesel from SHY zeolite gives the highest E A (98.65 kJ/mol). This result indicates that SHY zeolite is the best catalyst in terms of biodiesel yield and stability.

Clean Technologies and Environmental Policy, 2022

The Saudi economy is driven by the energy sector which mainly derived from petroleum-based resour... more The Saudi economy is driven by the energy sector which mainly derived from petroleum-based resources. Besides export, the Kingdom's consumption of this resource showed a significant increase which linearly promoting CO 2 emission increment. Therefore, it is essential to model the Kingdom's energy consumption to estimate the profile of her future energy consumption. This work explores modelling and multi-step-ahead predictions for energy use, gross domestic product (GDP), and CO 2 emissions in Saudi Arabia using previous data (1980-2018). The dynamic interrelationship of the variable's nexus was tested using the Granger causality and cointegration method in the short-run and long-run. In the long-run, the models reveal an inverted U-shape relation between CO 2 emissions and GDP, validating Environmental Kuznets curve. When energy consumption is increased by 1%, there will be an increase in CO 2 emissions by 0.592% at constant GDP, and when GDP is increased by 1%, there will be an increase in CO 2 emissions by 0.282% at constant energy used. CO 2 emissions appear to be both energy consumption and income elastic in Saudi Arabia in the long-run equilibrium. Granger causality based on vector error correction method reveals unidirectional causality from income to CO 2 emissions, and bidirectional causality from CO 2 emissions to energy consumption and vice versa in the short-run. In the long-run, bidirectional causality from income to CO 2 emissions and vice versa and unidirectional causality from the used energy to CO 2 emissions were observed. Also, there is a bidirectional causality from GDP to energy used and vice versa in the short-run, meaning that GDP and energy consumption are interdependent. Saudi Arabia needs to increase energy infrastructure investments and increase energy efficiency by implementing energy management policies, reducing environmental pollution, and preventing the negative effect on economic growth.

Journal of Alloys and Compounds

Chinese Journal of Chemical Engineering

INFORM International News on Fats, Oils, and Related Materials

Journal of Cleaner Production

Journal of Industrial and Engineering Chemistry

Applied Catalysis A: General

Energy Conversion and Management

Materials & Design, 2017

Hyperthermia cancer atherapy designed by magnetic particles as heating nano-mediators has been gr... more Hyperthermia cancer atherapy designed by magnetic particles as heating nano-mediators has been greatly applied for in vitro purposes to make reliable and certain conditions for in vivo trials. This intracellular treatment has found higher efficiency as compared to conventional ones due to generating heat locally through superparamagnetic nanoparticles for inaccessible tumors with minimal damage to the healthy cells nearby. The main challenges of this novel cancer therapy are the enhancement of heating power of such nanoparticles and the control of the local tumoral temperature. Those hyperthermia factors basically derived from magnetic nanoparticles as well as magnetic field. Thereby, the efficiency of magnetic hyperthermia is principally dependent on the proper determination of their features. This study tried to provide a comprehensive evaluation on the magnetic hyperthermia therapy through the determination of magnetic nanoparticles such as surface chemistry, intrinsic and extrinsic magnetic properties. In addition, the features of the magnetic field that substantially play on induction heating power and hyperthermia temperature are reviewed.

RSC Adv., 2016

Natural rubber is a tropical plantation crop that mainly consists of polyisoprene (cis-1,4-polyis... more Natural rubber is a tropical plantation crop that mainly consists of polyisoprene (cis-1,4-polyisoprene). It can be converted into fuels and other useful chemical commodities by depolymerization processes, with the hydrous pyrolysis being the most cost-effective.

Renewable and Sustainable Energy Reviews, 2016

Enzymatic hydroesterification has recently attracted research interest because of the high-value ... more Enzymatic hydroesterification has recently attracted research interest because of the high-value products created during biodiesel production. The use of this process overcomes problems related to conventional methods for biodiesel production, such as slow reaction rate and soap formation. The method comprises two basic processes to produce fatty acid alkyl esters from triacylglycerols, namely, enzymatic hydrolysis and enzymatic esterification. Although enzymatic hydroesterification for biodiesel production has many advantages, such as lower energy consumption and converting low-quality feedstock, it has not been used on an industrial scale mainly because of some impediments, including enzyme cost and conversion efficiency. This review presents a comprehensive evaluation of recent investigations on enzymatic hydrolysis and enzymatic esterification to lower process costs and increase yields.

Energy Conversion and Management, 2016

Energy Conversion and Management, 2015

ABSTRACT This study optimized the use of biomass waste to generate fuel through co-pyrolysis. In ... more ABSTRACT This study optimized the use of biomass waste to generate fuel through co-pyrolysis. In this paper, the effects of stepwise co-pyrolysis temperature and different ratios between palm shells and scrap tires in feedstock were studied to observe any improvements in the quantity and quality of the liquid yield and its byproduct. The ratio of palm shells and scrap tires varied at 100:0, 75:25, 50:50, 25:75, and 0:100. The experiment was conducted in a fixed-bed reactor. The study was divided into two scenarios. The first scenario was performed at the optimum temperature of 500 °C with a reaction time of 60 min. In the second scenario, the temperature was set at 500 °C for 60 min before the temperature was increased to 800 °C with a high heating rate. After the temperature reached 800 °C, the condition was maintained for approximately 45 min. Results showed that an increase in the liquid and gas yields was achieved when the temperature increased after optimum conditions. Increased yield was also obtained when the proportion of scrap tire was increased in the feedstock. Several other important findings are discussed in this paper, including the phases of pyrolysis oil, features of the liquid product, and characteristics of the byproducts. All products from both scenarios were analyzed by various methods to understand their fuel characteristics.

Energy Conversion and Management, 2014

The oil produced by the pyrolysis of biomass has potential for use as a substitute for fossil fue... more The oil produced by the pyrolysis of biomass has potential for use as a substitute for fossil fuels. However, the oil needs to be upgraded since it contains high levels of oxygen, which causes low caloric value, corrosion problems, and instability. Generally, upgrading the pyrolysis oil involves the addition of a catalyst, solvent and large amount hydrogen, which can cost more than the oil itself. In this regard, the co-pyrolysis technique offers simplicity and effectiveness in order to produce a high-grade pyrolysis oil. Co-pyrolysis is a process which involves two or more materials as feedstock. Many studies have shown that the use of co-pyrolysis is able to improve the characteristics of pyrolysis oil, e.g. increase the oil yield, reduce the water content, and increase the caloric value of oil. Besides, the use of this technique also contributed to reduce the production cost and solve some issues on waste management. This article tried to review the co-pyrolysis process through several points of view, including the process mechanism, feedstock, the exploration on co-pyrolysis studies, co-pyrolysis phenomena, characteristics of byproducts, and economic assessment. Additionally, several outlooks based on studies in the literature are also presented in this paper.

BioEnergy Research, 2013

ABSTRACT The residues from the palm oil industry are the main contributors to biomass waste in Ma... more ABSTRACT The residues from the palm oil industry are the main contributors to biomass waste in Malaysia, and these wastes require extra attention with respect to handling. The biomass waste is a renewable resource that can potentially be used to produce absorbents, fuels, and chemical feedstocks through the pyrolysis process. In this study, the wastes of palm shell, empty fruit bunches, and mesocarp fiber were characterized and then pyrolyzed in a fixed-bed reactor under the following conditions: a temperature of 500 °C, a nitrogen flow rate of 2 L/min and reaction time of 60 min. After pyrolysis, characterization of the products with an emphasis on the bio-oil and the bio-char was performed using various approaches (including Karl Fischer water-content tests, FTIR, SEM, TGA and CNH/O analyses). The results showed that the pyrolysis of palm oil wastes yielded more bio-oil than bio-char or non-condensable gases. The results also indicated that all of the bio-oils were acidic and contained high levels of oxygen. The bio-oils heating values were low and varied from 10.49 MJ/kg to 14.78 MJ/kg. The heating values of the bio-chars (20–30 MJ/kg) were higher than those of the bio-oils. Among the biomasses studied in this work, palm shell contained the highest level of lignin and showed the highest levels of bio-char yield and fixed and elemental carbon in the raw and bio-char form.

Energy Conversion and Management, 2013

Oil palm tree residues are a rich biomass resource in Malaysia, and it is therefore very importan... more Oil palm tree residues are a rich biomass resource in Malaysia, and it is therefore very important that they be utilized for more beneficial purposes, particularly in the context of the development of biofuels. This paper described the possibility of utilizing oil palm tree residues as biofuels by producing bio-oil and bio-char via pyrolysis. The process was performed in a fixed-bed reactor at a temperature of 500°C, a nitrogen flow rate of 2 L/min and a reaction time of 60 min. The physical and chemical properties of the products, which are important for biofuel testing, were then characterized. The results showed that the yields of the bio-oil and bio-char obtained from different residues varied within the ranges of 16.58-43.50 wt% and 28.63-36.75 wt%, respectively. The variations in the yields resulted from differences in the relative amounts of cellulose, hemicellulose, lignin, volatiles, fixed carbon, and ash in the samples. The energy density of the bio-char was found to be higher than that of the bio-oil. The highest energy density of the bio-char was obtained from a palm leaf sample (23.32 MJ/kg), while that of the bio-oil was obtained from a frond sample (15.41 MJ/kg).