Jabbar GARDY - Academia.edu (original) (raw)

Papers by Jabbar GARDY

Desalination, 2022

Forward osmosis (FO) is increasingly being studied as an alternative desalination technique to th... more Forward osmosis (FO) is increasingly being studied as an alternative desalination technique to the other conventional desalination technologies, owing primarily to its low energy potential. However, the co-opted energy limitations in the draw solution (DS) regeneration stage in FO desalination processes and the lack of effective DS have hampered FO's implementation for potable water application on an industrial scale. In this work, we explored the Donnan principle to engineer a DS material having the duality of magnetic and solar-thermal separability functionalities from a sustainability viewpoint whilst exploiting a careful selection of material properties. A novel potassium functionalised iron oxide doped carbon nanofibres (K/Fe3O4/CNF) magnetic nanoparticles (MNPs) was successfully synthesised for FO desalination applications, utilising an eco-friendly strategy that improves hydrophilicity of DS without polymers. The novel DS obtained a significant osmotic pressure (86.1 bar), whilst it FO performance showed a small reverse salt flux (RSF) and specific reverse salt flux (SRSF) values of 0.10 gMH and 0.004 g/L, respectively. These values compare to at least <10 % of most RSF and SRSF values reported in the literature. The facile DS synthesis strategy adopted herein will potentially open a new route to preparing other DS nanomaterials with unique multi functionalities and enhanced hydrophilicity devoid of polymers. Whilst magnetic DS re-concentration may be achievable, additional research is required to appraise this methodology's overall energy implications and economic advantages over existing DS recovery methods.

Catalysts MDPT, 2022

There is an urgent need to reduce global greenhouse gas emissions, yet to date the decarbonizatio... more There is an urgent need to reduce global greenhouse gas emissions, yet to date the decarbonization of the transportation industry has been slow and of particular difficulty. While fossil fuel replacements such as biodiesel may aid the transition to a less polluting society, production at the industrial scales required is currently heavily dependent on chemical catalysis. Conventional two-step homogenous routes require the challenging separation of catalyst from the obtained product; however, heterogenous solid catalysts bring new considerations such as material stability, surface area, porosity, deactivation effects, and reduced reactivities under mild conditions. Nanomaterials present an attractive solution, offering the high reactivity of homogenous catalysts without complex recyclability issues. Slightly less reactive, acidic sulfated nanomaterials may also demonstrate greater stability to feedstock impurity, extending lifetime and improved versatility to a range of starting feeds. There remains, however, much work to be done in demonstrating the full-scale feasibility of such catalysts. This review explores recent developments over time in acidic sulfated nanocatalysis for biodiesel production, with particular focus on metal oxides, magnetic nanoparticles, silica-supported nanomaterials, and acidic carbon nanocatalysts. Included are various summaries of current progress in the literature, as well as recommendations for future research.

Desalination, 2022

Damage to the environment as a consequence of exploration, production, imminent depletion, use of... more Damage to the environment as a consequence of exploration, production, imminent depletion, use of fossil fuels and concerns over climate change (increasing lifecycle greenhouse gas emissions), has increased the need for a more eco-friendly, renewable and sustainable source of energy. The level of biodiesel production has been increasing over the last twenty years, reflecting a rapid rise in demand due to its availability, renewability, lower gas emissions, non-toxicity, and its biodegradability. The impact of CO2 emissions on climate change, worldwide industrialisation, countries not having oilfields and need for a strategic and alternative source of energy have also driven an ever increasing demand. Biodiesel is mainly produced in industry by the transesterification process of triglycerides with low molecular weight alcohols using homogenous acid or base catalysts. However, the biodiesel industry faces some significant challenges; (i) high cost of biodiesel feedstock and (ii) the c...

Catalytic transesterification of triglycerides and esterification of free fatty acids underpins s... more Catalytic transesterification of triglycerides and esterification of free fatty acids underpins sustainable biodiesel production, wherein efficient heterogeneous catalysts are sought to replace mineral acids. A robust, magnetic core-shell SO₄/Mg-Al-Fe₃O₄ catalyst was synthesised by stepwise co-precipitation, encapsulation, and surface functionalisation. The resulting magnetically-separable catalyst has a surface area of 123 m² g⁻¹, uniform 6.5 nm mesopores, and a high total acid site loading of 2.35 mmol g⁻¹. Optimum conditions for the (trans)esterification of waste cooking oil (WCO) over the sulfated solid acid catalyst were 95 °C, a methanol:WCO molar ratio of 9:1, and 300 min reaction to achieve 98.5% FAME yield. Esterification of oleic acid to methyl oleate resulted in an 88% yield after 150 min under the same reaction conditions. The magnetic solid acid catalyst exhibited good thermal and chemical stability and enabled facile catalyst separation post-reaction and the production...

Use of Biodiesel as an alternative source of fuel has been increasing over the last ten years, re... more Use of Biodiesel as an alternative source of fuel has been increasing over the last ten years, reflecting a rapid rise in demand due to global industrialisation, coupled with recognition by countries with no oilfields of the need for a strategic and alternative source of energy [1, 2]. Unlike petrodiesel, biodiesel satisfies the 1990 amendment to the Clean Air Act, on account of the almost zero emission of sulfur oxides [3]. However, some of its physicochemical properties including cold flow properties have proved a major drawback to its usage. Furthermore, the cost of biodiesel – it is roughly 1.5 times more expensive than its fossil-based counterpart and this has been the major drawback in making commercial progress and gaining universal acceptance. An approach to lower the cost of production is maximising use of cheap feedstock such as used cooking oil for biodiesel. Used cooking oil can be “pre-blended” with other feedstock prior to the process of transesterification or alternat...

Proceedings of The 9th International conference on Research in Engineering, Science and Technology, 2019

Chemists have attempted to minimize waste by designing new and more environmentally friendly meth... more Chemists have attempted to minimize waste by designing new and more environmentally friendly methods for synthesizing catalysts. They produced an array of improved methodologies, including the use of locally available raw materials such as clay or modified clay instead of chemicals for catalyst preparation. The present study highlights the synthesis and characterization of hierarchical catalyst from locally available montmorillonite. The synthesised catalyst was characterized by, Powder X-ray diffraction, X-Ray Fluorescence (XRF), Forier Transform infrared (FT-IR) spectroscopy, N2 adsorption-desorption isotherms, Scanning electron microscopy (SEM), Thermo gravimetric analysis (TGA), for their crystal structure, surface analysis, morphology, thermal stability and catalytic performance. The synthesized catalyst designed to fit specific reaction for pharmaceutical preparation.

Processes

Currently over 845 million people are believed to be living under severe water scarcity, and an e... more Currently over 845 million people are believed to be living under severe water scarcity, and an estimated 2.8 billion people across the globe are projected to come under serious water scarcity by the year 2025, according to a United Nations (UN) report. Seawater desalination has gained more traction as the solution with the most potential for increasing global freshwater supplies amongst other solutions. However, the economic and energy costs associated with the major desalination technologies are considered intrinsically prohibitive largely due to their humongous energy requirements alongside the requirements of complex equipment and their maintenance in most cases. Whilst forward osmosis (FO) is being touted as a potentially more energy efficient and cost-effective alternative desalination technique, its efficiency is challenged by draw solutes and the draw solutes recovery step in FO applications alongside other challenges. This paper looks at the present situation of global wate...

DESALINATION AND WATER TREATMENT

Biodiesel is a promising liquid fuel that is mainly derived from triglycerides and is utilized in... more Biodiesel is a promising liquid fuel that is mainly derived from triglycerides and is utilized in diesel engines directly or after blending with conventional gasoline. Triglycerides comprise fatty acid methyl esters (FAME), which are generated from plant or animal based sources. Biodiesel generated from vegetable oils is expensive than petroleum-based diesel and has concerns with food vs. fuels debate. Therefore, biodiesel from renewable sources such as non-food feedstocks has attained a considerable interest in last two decades. This paper aims to examine the biodiesel generation from the non-food feedstocks available in the Kingdom of Saudi Arabia (KSA) as a source of renewable energy and valueadded products along with and a solution to current waste disposal problems. In KSA, non-food feedstocks such as animal fats, waste cooking oil (WCO), agricultural wastes, sewage sludge, and microalgae are promising sources for biodiesel production. These feedstocks are relatively cheap, easily available, portable, and renewable in nature. A case study of waste to biodiesel refinery is presented for KSA under three different scenarios, including (1) KSA population in 2017, (2) KSA population and pilgrims in 2017, and (3) KSA population and pilgrims by 2030. It was assessed that around 482, 488 and 627 MW of electricity on a continuous basis could be generated every year for scenarios 1, 2 and 3 respectively if using the fat fraction of municipal solid waste in waste to biodiesel refineries in KSA. Similarly, a total net savings of US$ 272, 275.2 and 353.9 million can be achieved from scenarios 1, 2 and 3 respectively. However, there are many challenges in commercializing the waste to biodiesel refinery in KSA such as collection of feedstocks, separation of lipids, products separation, soap formation, preserving products, and adequate regulations.

A novel solid acid nano-catalyst [Ti(SO4)O] was synthesised and used for the simultaneous esterif... more A novel solid acid nano-catalyst [Ti(SO4)O] was synthesised and used for the simultaneous esterification and transesterification of free fatty acids in used cooking oil (UCO) to produce biodiesel. The synthesised nano-catalyst was fully characterised by different analytical techniques. The XPS results clearly confirmed that the bidentate sulphate coordinated to the Ti4+ metal in the nano-catalyst product. Obtained d-spacing values from the experimental data of XRD peaks and the SAED pattern of produced nano-catalyst agreed well with the d-spacing values from the JCPDS-ICDD card numbers 04-011-4951 for titanium sulphate oxide or titanium oxysulfate crystal structures.This confirms the sulphate groups were within the crystalline structure rather than on the surface of titania nanoparticles, which has not been previously reported. It has been demonstrated 97.1% yield for the fatty acid methyl ester can be achieved usign the synthetised catalyst under a reaction time of 3 hrs, catalyst ...

American Journal of Applied Chemistry, Nov 28, 2014

ABSTRACT The energy consumption in Saudi Arabia has increased significantly in recent years due t... more ABSTRACT The energy consumption in Saudi Arabia has increased significantly in recent years due to a rapidly growing population and economic development. The current peak demand of electrcity is 55 GW and it is projected to become 120 GW in the year 2032. Fossil fuels are the only choice to meet the energy requirements. The government plans to double its energy generating capacity by 2020, of which around 85% will come from renewable resources. Natural zeolites are found abundantly in Saudi Arabia and have a significant role in the energy generation applications. Natural zeolites samples have been collected from the Jabal Shama occurrence near Jeddah city. All of the samples showed the standard zeolite group of alumina-silicate minerals with the presence of other elements such as Na, Mg and K etc. A highly crystalline structure is found in natural zeolites, which is critical when using in the energy applications as a process catalyst. However, there is a need of special milling and purification process to achieve homogeneous particle morphology and sizes in a range of sub-micron to nano-meter without impurities. This will significantly increase the surface area and pore volume of natural zeolites, thus improving their properties as a process catalyst and optimizer. The aim of this paper is to investigate the potential and utilization of naturally occurring zeolites in Saudi Arabia for pyrolysis of waste plastic to fuel oil.

Applied Catalysis B: Environmental, 2019

Catalytic transesterification of triglycerides and esterification of free fatty acids underpins s... more Catalytic transesterification of triglycerides and esterification of free fatty acids underpins sustainable biodiesel production, wherein efficient heterogeneous catalysts are sought to replace mineral acids. A robust, magnetic core-shell SO 4 /Mg-Al-Fe 3 O 4 catalyst was synthesised by stepwise co-precipitation, encapsulation, and surface functionalisation. The resulting magnetically-separable catalyst has a surface area of 123 m 2 g −1 , uniform 6.5 nm mesopores, and a high total acid site loading of 2.35 mmol g-1. Optimum conditions for the (trans) esterification of waste cooking oil (WCO) over the sulfated solid acid catalyst were 95°C, a methanol:WCO molar ratio of 9:1, and 300 min reaction to achieve 98.5% FAME yield. Esterification of oleic acid to methyl oleate resulted in an 88% yield after 150 min under the same reaction conditions. The magnetic solid acid catalyst exhibited good thermal and chemical stability and enabled facile catalyst separation post-reaction and the production of high quality biodiesel.

Applied Energy, 2018

Forward osmosis (FO) is an emerging technology for water desalination which requires no external ... more Forward osmosis (FO) is an emerging technology for water desalination which requires no external force for its operation. The performance of FO for water desalination is dependent on draw solution (DS) that must provide high osmosis pressure, minimum reverse flux and efficient separation of water. This work proposes an innovative concept of energy efficient material as DS having two functions, i.e. high osmotic pressure and efficient absorption of solar energy for the regeneration phase. The potassium functionalised carbon nanofibers (K/CNF) which are highly solar absorptive, are engineered and suspended in triethylene glycol (TEG) aqueous solution with different concentrations to act as a novel DS. The TEG-K/CNF is fully characterised for morphological appearance and thermophysical characteristics before using in FO experiments. It is found that the osmotic pressure and water flux of the novel DS are directly dependent on the concentration of K/CNF and TEG. The draw solution is re-concentrated by evaporating the water aided by the highly solar absorptive K/CNF under simulated solar flux. The vapours are condensed and the quality of product water is found to be comparable with potable water standard. The novel concept proposed in this study has the potential to be used in arid areas where solar energy is abundant to fulfill the potable water needs.

Journal of Environmental Management , 2019

Damage to the water resources and environment as a consequence of oil production and use of fossi... more Damage to the water resources and environment as a consequence of oil production and use of fossil fuels, has increased the need for applying various technologies and developing effective materials to remove contaminates from oily wastewaters resources. One of the challenges for an economic industrial wastewater treatment is separation and reusability of the developed purifying agents. Development of magnetic materials could potentially facilitate easier and more economic separation of purifying agents. Therefore, herein we have synthesised an efficient and easily recyclable Fe3O4/mordenite zeolite using a hydrothermal process to investigate its purification capability for wastewater from Kermanshah oil refinery. The synthesised Fe3O4/mordenite zeolite was characterised using XRD, FTIR, SEM, EDX, XRF and BET analysis. XRD result showed that the synthesised Fe3O4/mordenite zeolite comprised sodium aluminium silicate hydrate phase [01-072-7919, Na8(Al6Si30O72)(H2O)9.04] and cubic iron oxide phase [04-013-9808, Fe3O4]. Response Surface Method (RSM) combined with Central Composite Design (CCD) was used to identify the optimum operation parameters of the pollutant removal process. The effect of pH, contact time and Fe3O4/mordenite zeolite amount on the Chemical Oxygen Demand (COD), Biochemical Oxygen Demand (BOD) and Nephelometric Turbidity Unit (NTU) were investigated. It was found that pH was the most significant factor influencing COD and BOD removal but the quantity of Fe3O4/mordenite zeolite was the most influential factor on the turbidity removal capacity. The optimum removal process conditions were identified to be pH of 7.81, contact time of 15.8 min and Fe3O4/mordenite zeolite amount of 0.52% w/w. The results show that the regenerated Fe3O4/mordenite zeolite can be reused for five consecutive cycles in purification of petroleum wastes.

ChemEngineering , 2019

This work highlights how the treatment of ZSM-5 (parent Zeolite Socony Mobil–5, Si/Al = 23) with ... more This work highlights how the treatment of ZSM-5 (parent Zeolite Socony Mobil–5, Si/Al = 23) with different surfactant templates and alkaline solution, improved the catalytic performance in the Friedel-Crafts acylation of anisole with a propionic anhydride to obtain p-methoxypropiophenone. The modified microporous to mesoporous zeolite catalysts were characterized using different analytical techniques, including X-ray diffraction (XRD), nitrogen porosimetry, Fourier-transform infrared spectroscopy (FT-IR), temperature-programmed desorption (ammonia-TPD) and field emission scanning electron microscopy (FE-SEM) to analyze the crystallographic structure, surface acidity, surface area, porosity, morphology, and particle size. The results showed that the formed mesoporous zeolite by NaOH solution had smaller mesopores (ca. 3.7 nm) as compared to the mesoporous zeolites obtained by surfactant templates, such as, CTAB (ca. 14.9 nm), TPAOH (ca. 11.1 nm) and mixture of CTAB/TPAOH (ca. 15.2 nm). The catalytic acylation reaction was conducted in a batch glass reactor at various temperatures and the products were analyzed using off-line gas chromatography–mass spectrometry (GC-MS). It was found that the activity of treated ZSM-5 with mixed surfactant templates (CTAB/TPAOH) exhibited enhanced selectivity towards the main product (p-methoxypropiophenone) by a factor 1.7 or higher than unmodified ZSM-5 due to its increased surface area by 1.5 times and enhanced acid sites.

Desalination, 2022

Catalysts MDPT, 2022

Desalination, 2022

Proceedings of The 9th International conference on Research in Engineering, Science and Technology, 2019

Processes

DESALINATION AND WATER TREATMENT

American Journal of Applied Chemistry, Nov 28, 2014

Applied Catalysis B: Environmental, 2019

Catalytic transesterification of triglycerides and esterification of free fatty acids underpins s... more Catalytic transesterification of triglycerides and esterification of free fatty acids underpins sustainable biodiesel production, wherein efficient heterogeneous catalysts are sought to replace mineral acids. A robust, magnetic core-shell SO 4 /Mg-Al-Fe 3 O 4 catalyst was synthesised by stepwise co-precipitation, encapsulation, and surface functionalisation. The resulting magnetically-separable catalyst has a surface area of 123 m 2 g −1 , uniform 6.5 nm mesopores, and a high total acid site loading of 2.35 mmol g-1. Optimum conditions for the (trans) esterification of waste cooking oil (WCO) over the sulfated solid acid catalyst were 95°C, a methanol:WCO molar ratio of 9:1, and 300 min reaction to achieve 98.5% FAME yield. Esterification of oleic acid to methyl oleate resulted in an 88% yield after 150 min under the same reaction conditions. The magnetic solid acid catalyst exhibited good thermal and chemical stability and enabled facile catalyst separation post-reaction and the production of high quality biodiesel.

Applied Energy, 2018

Journal of Environmental Management , 2019

ChemEngineering , 2019