Muhammad Ayoub

Selective Monolaurin Synthesis through Esterification of Glycerol Using Sulfated Zirconia-Loaded SBA-15 Catalyst

The selective conversion of lauric acid to glycerol monolaurin over sulfated zirconia SBA prepared under various conditions was investigated in this study. The structural properties of the prepared catalysts were characterized using different characterization techniques. Sulfated zirconia was successfully incorporated with improved properties, such as larger mesopore surface area; the mesoporous structure was preserved as well. The highest yield of 79.1% was obtained during reaction over SZSBA-15 catalyst with 16 wt.% zirconium oxychloride loading and 3 h of reflux time. About 83.4% selectivity toward monolaurin was achieved at a high conversion of lauric acid (94.9%), a lauric acid-to-glycerol molar ratio of 4.0, within 6 h, and at 160°C. Product distribution was successfully elucidated. High selectivity to monolaurin was influenced by molecular sieving effects.

Carbon dioxide capture via aqueous N-methyldiethanolamine (MDEA)-1-butyl-3-methylimidazolium acetate ([bmim][Ac]) hybrid solvent

In this study, aqueous hybrid solvents from a mixture of aqueous N-methyldiethanolamine (MDEA) and 1-butyl-3-methylimidazolium acetate, [bmim][Ac] as ionic liquids (ILs) were formulated at different mass ratio. In each aqueous hybrid solvents, the concentrations of MDEA were kept constant at 30 wt%. In the hybrid solvents, the solubility of CO2 was investigated at [bmim][Ac] concentration of 10 wt% and 20 wt%, respectively and results were compared with pure aqueous MDEA solvent. It was observed that the solubility of CO2 is significantly improved in the hybrid solvent as compared to the solubility of CO2 in pure aqueous MDEA solvent. However, increasing the concentration of [bmim][Ac] from 10 wt% to 20 wt% has a negative effect on the solubility of CO2 due to viscosity effect. It was also observed that hybrid solvents with 10 wt% [bmim][Ac] has better CO2 loading capacity. Increasing pressure from 10 bar to 20 bar has demonstrated an increase in CO2 absorption capacity as well as CO2 absorption rate. Hybrid solvents prepared from amine and imidazolium ILs will be a promising solvent in the capturing of CO2.In this study, aqueous hybrid solvents from a mixture of aqueous N-methyldiethanolamine (MDEA) and 1-butyl-3-methylimidazolium acetate, [bmim][Ac] as ionic liquids (ILs) were formulated at different mass ratio. In each aqueous hybrid solvents, the concentrations of MDEA were kept constant at 30 wt%. In the hybrid solvents, the solubility of CO2 was investigated at [bmim][Ac] concentration of 10 wt% and 20 wt%, respectively and results were compared with pure aqueous MDEA solvent. It was observed that the solubility of CO2 is significantly improved in the hybrid solvent as compared to the solubility of CO2 in pure aqueous MDEA solvent. However, increasing the concentration of [bmim][Ac] from 10 wt% to 20 wt% has a negative effect on the solubility of CO2 due to viscosity effect. It was also observed that hybrid solvents with 10 wt% [bmim][Ac] has better CO2 loading capacity. Increasing pressure from 10 bar to 20 bar has demonstrated an increase in CO2 absorption capacity as well as CO2 absorption rate. Hyb...

Carbon capture from natural gas using multi-walled CNTs based mixed matrix membranes

ABSTRACT Most of the polymers and their blends, utilized in carbon capture membranes, are costly, but cellulose acetate (CA) being inexpensive is a lucrative choice. In this research, pure and mixed matrix membranes (MMMs) have been fabricated to capture carbon from natural gas. Polyethylene glycol (PEG) has been utilized in the fabrication of membranes to modify the chain flexibility of polymers. Multi-walled carbon nanotubes (MWCNTs) provide mechanical strength, thermal stability, an extra free path for CO2 molecules and augment CO2/CH4 selectivity. Membranes of pure CA, CA/PEG blend of different PEG concentrations (5%, 10%, 15%) and CA/PEG/MWCNTs blend of 10% PEG with different MWCNTs concentrations (5%, 10%, 15%) were prepared in acetone using solution casting techniques. Fabricated membranes were characterized using SEM, TGA and tensile testing. Permeation results revealed remarkable improvement in CO2/CH4 selectivity. In single gas experiments, CO2/CH4 selectivity is enhanced 8 times for pure membranes containing 10% PEG and 14 times for MMMs containing 10% MWCNTs. In mix gas experiments, the CO2/CH4 selectivity is increased 13 times for 10% PEG and 18 times for MMMs with 10% MWCNTs. Fabricated MMMs have a tensile strength of 13 MPa and are more thermally stable than CA membranes. GRAPHICAL ABSTRACT

New trends in improving gasoline quality and octane through naphtha isomerization: a short review

The octane enhancement of light straight run naphtha is one of the significant solid acid catalyzed processes in the modern oil refineries due to limitations of benzene, aromatics, and olefin content in gasoline. This paper aims to examine the role of various catalysts that are being utilized for the isomerization of light naphtha with an ambition to give an insight into the reaction mechanism at the active catalyst sites, and the effect of various contaminants on catalyst activity. In addition, different technologies used for isomerization process are evaluated and compared by different process parameters.Graphical abstract

Simulation for the production of synthetic natural gas for vehicles (SNGV) from palm waste via gasification with in-situ CO 2 capture

Due to abundance of oil palm waste worldwide, it is a good candidate to be used as a feedstock for synthetic natural gas for vehicles (SNGV) production. Biomass gasification is one of the promising methods for SNGV production. This work focuses on the gasification with in-situ CO2 capture using CaO as absorbent materials for SNGV production from palm oil empty fruit bunch (EFB). Two parameters (temperature 500–900°C and steam/biomass ratio 1–2.2) have been studied on the production of SNGV via simulation approach in ASPEN HYSYS. The model has been also validated with literature and showed good agreement. The results showed that the EFB has good potential to produce higher yield of SNGV at lower temperature. The higher value of SNGV (4 kg/hr) is obtained due to the lower concentration of CO2 caused by using CaO as sorbent material.

Experimental Investigation of Polyvinylpyrrolidone for Application as a Demulsifier for Water-in-Oil Emulsion

Emulsification of produced immiscible mixed liquid of oil and water is a problem frequently recognized in surface production facilities in oil fields. The formed emulsions are required to be demulsified to avoid the negative consequences on piping and processing equipment. Nowadays, chemical demulsification is a preferable method to avoid or retard emulsification during the process of oil treatment.

Examination and Improvement of Salama Model for Calculation of Sand Erosion in Elbows

Sand erosion is a problem recognized in many facilities and piping components used in production, treatment, and transportation of oil and gas. Proper controlling of sand erosion requires early prediction at different conditions and within various ranges of flow parameters. Numerous models and correlations are available for sand erosion prediction in varies components. The applicability and accuracy of the available models depends on many factors such as the range of conditions and the number of parameters that are taken into account in developing the model. One of the models widely used for sand erosion prediction is Salama model, which is used for calculation of sand erosion in elbows and tees. In spite of Salama model’s simplicity, it is not recommended to use in many cases due to decrease in accuracy. Salama model accuracy, in general, decreases when it is applied to viscous fluids flow and low gas–liquid-ratio multiphase flow. In this paper, the discrepancy of Salama model with field data was confirmed by comparing its output with published measured data. The model was, then, improved by comparing its results with three sets of measured sand erosion data for pure gas, high gas–liquid-ratio fluids, and low gas–liquid-ratio fluids. The model improvement results in three models for prediction of sand erosion in elbows with higher accuracy.

Toxicity of Several Potassium Carbonate and Phosphonium-Based DeepEutectic Solvents towards Escherichia coli and Listeria monocytogenesBacteria

Deep eutectic solvents (DESs) and ternary deep eutectic solvents (TDESs) and are derived from two or more salts as the hydrogen bond acceptors (HBAs) and hydrogen bond donors (HBDs). In this work, the several DESs and a TDES were prepared. Allyltriphenyl phosphonium bromide and potassium carbonated were selected as HBAs to mix with various HBDs such as glycerol (GL), ethylene glycol (EG), diethylene glycol (DEG) and triethylene glycol (TEG) into different molar ratios. Two different groups of bacteria were selected for investigation of toxicity of species, namely Escherichia coli (EC) as a Gram negative bacterium and Listeria monocytogenes (LM) as a Gram positive bacterium. The results revealed that by increasing alkyl chain length on HBD, the toxicity of DESs increases towards EC bacterium. However, there appears to have no direct relationship between effect of alkyl chain length and toxicity DESs towards LM bacterium. Moreover, by studying the effect of molar ratio the toxicity of DESs, it was observed that there is no direct relationship between them. Furthermore, it was found that the type of HBD has a dominant effect on the toxicity of DESs compared to type of salt. By comparing the toxicity of DESs in this work with that of ILs in literature, it was found that DESs are less toxic than ILs. The last interesting result of this work is that TDES exhibited the lowest toxicity on EC and LM bacteria compared with DESs.

Conversion of glycerol to polyglycerol over waste duck-bones as a catalyst in solvent free etherification process

The alkaline catalyst derived from the duck-bones was used for conversion of glycerol to polyglycerol via solvent free etherification process. The physicochemical properties of prepared materials were duck–bones were systematically investigated as a catalyst by latest techniques of Thermo gravimetric analysis (TGA), X-ray diffraction (XRD), and Brunauer-Emmett-Teller (BET) surface properties. TGA showed different trends of duck–bones decomposition from room temperature to 1000C. XRD pattern showed a clear and sharp peaks of a crystalline phase of CaO. The activity of the catalysts was in line with the basic amount of the strong base sites, surface area, and crystalline phase in the catalysts. The prepared catalyst derived from duck–bones provided high activity (99 %) for glycerol conversion and around 68 % yield for polyglycerol production. These ample wastes of duck–bones have good potential to be used as polyglycerol production catalysts due to have high quantity of Ca compare to other types of bones like cow, chicken and fish bones.

The effects of salt, particle and pore size on the process of carbon dioxide hydrate formation: A critical review

Hydration is an alternative method for CO2 capture. In doing so, some researchers use porous media on an experimental scale. This paper tries to gather the researches on the formation of CO2 hydrate in different types of porous media such as silica sand, quartz sand, Toyoura, pumice, and fire hardened red clay. This review has attempted to examine the effects of salt and particle sizes as two major factors on the induction time, water to hydrate conversion, gas uptake (or gas consumption), and the rate of CO2 hydrate formation. By performing a critical assessment of previous research works, it was observed that the figure for the gas uptake (or gas consumption) and water to hydrate conversion in porous media was decreased by increasing the particle size provided that the pore size was constant. Although, salt can play a role in hydrate formation as the thermodynamic inhibitor, the results show that salt can be regarded as the kinetic growth inhibitor and kinetic promoter. Because of the fact that the gas ...