Lukman Ismail

Oleate Ester-Derived Nonionic Surfactants: Synthesis and Cloud Point Behavior Studies

The synthesis and cloud point behavior of high oleate ester-derived nonionic surfactants are now reported. The effect of various polyethoxylate chain lengths (polyethylene glycol with 7, 11, and 16 units of ethylene oxide (EO) monomer) as the surfactants hydrophilic head on the cloud point was investigated. The effect of varying amounts of sodium chloride and five different ionic surfactants on the cloud points of the synthesized nonionic surfactants were also presented. When the chain length of polyethoxylate increased, the cloud point of the synthesized nonionic surfactant also increased, ranging from 16°C, 43°C, and 64°C for 7, 11, and 16 EO units, respectively. Increments in sodium chloride concentration depressed the cloud point values of the synthesized nonionic surfactants linearly. The addition of ionic surfactants elevated the cloud points of the synthesized nonionic surfactant. However, in the presence of sodium chloride, the cloud point of the mixed ionic-nonionic solution was suppressed and anincrease in ionic surfactant concentration was required to elevate the cloud point. It was also found that the cloud points of synthesized surfactants can be raised up to 95°C in the presence of 4wt% NaCl solution.

Novel Surfactant for the Reduction of CO2/Brine Interfacial Tension

The synthesis of novel CO2 philic surfactant using maleic anhydride and dipropylene tertiary butyl alcohol is reported. The synthesis involved the esterification of maleic anhydride to produce bis(2-(2-(tert-butoxy)propoxy)propyl) maleate and subsequent sulfonation of the esterified product. Para toluene sulfonic acid was employed as catalyst for the esterification reaction. The esterification reaction was optimized for the maximum yield of 98% of bis(2-(2-(tert-butoxy)propoxy)propyl) maleate. The esterification reaction kinetics employing heterogeneous catalyst were also studied. Although this is a bimolecular reaction, a first order reaction kinetics with respect to acid has been observed. The activation energy was found to be 58.71 kJ/mol. The diester was followed by the sulfonation process and a yield of 85% of surfactant was achieved. The synthesized surfactant successfully lowered down the IFT between CO2/brine to 1.93 mN/m. This surfactant has a great potential to be used for CO2-EOR applications.

Synthesis of a New CO2 Philic Surfactant for Enhanced Oil Recovery Applications

The synthesis of CO2 philic surfactant using maleic anhydride and 4-tert-butylbenzyl alcohol is reported. We reacted maleic anhydride with 4-tert-butylbenzyl alcohol to form bis(4-(tert-butyl)benzyl) fumarate and sulfonated the produced diester. The esterification reaction was optimized for a maximum yield of 98% of bis(4-(tert-butyl)benzyl) fumarate. First-order reaction kinetics with respect to acid was observed. The activation energy was found to be 55.62 kJ/mol. The sulfonated product of diester was obtained by the sulfonation reaction and the yield of 82% of surfactant was achieved. The in-house developed surfactant effectively lowered down the IFT between CO2/brine to 4.2 mN/m. This surfactant is targeted for CO2-EOR applications.

Study of 1-(2-hydroxyethyle) 3-methylimidazolium halide as thermodynamic inhibitors

In this study, the performance of 1-(2-Hydroxyethyle) 3-methylimidazolium chloride [OH-EMIM][Cl] and 1-(2-Hydroxyethyle) 3-methylimidazolium bromide [OH-EMIM][Br] was investigated as thermodynamic gas hydrate inhibitors. The dissociation temperature was determined for methane gas hydrates using a high pressure micro deferential scanning calorimeter at a pressure range of 36-97 bar. Both ionic liquids (ILs) were studied at concentrations of 5, 10, 15, 20 and 25 wt% then their performance was compared with commercially available inhibitors. It was observed that both ILs shift the methane hydrate equilibrium curve to lower temperature and higher pressure; and the performance of [OH-EMIM][Cl] is better than [OH-EMIM][Br]. Nevertheless both of them were found to be less effective compared to methanol and mono ethylene glycol.

Comparison of Using NaOH and KOH Activated Fly Ash-Based Geopolymer on the Mechanical Properties

Geopolymer synthesis has two main requirements to fulfil which are the source material that is rich in Silicon (Si) and Aluminum (Al) and alkali activator such as sodium/potassium hydroxide. Sodium hydroxide (NaOH) is widely used for the synthesis of geopolymer compared to potassium hydroxide (KOH) with addition of silicate solution for the purpose of increasing dissolution process. However, the comparison of using different activator in the absence of silicate solution for geopolymer synthesis is not well established. This paper presents an evaluation on compressive strength of fly ash–based geopolymer by using different activator (KOH and NaOH) with respect to different curing conditions (time and temperature) in the absence of sodium silicate. The samples were mixed using mortar mixer and prepared in 50mm x 50mm x 50mm mould for determination of compressive strength. It can be observed that the highest compressive strength up 65.28 MPa was obtained using NaOH. Meanwhile, synthesis using KOH only recorded 28.73 MPa. The compressive strength was better when cured at elevated temperature (60°C) than room temperature (25°C). Further analysis on the microstructure of the highest compressive strength geopolymer samples for both activators was carried out using Field Emission Scanning Microscopy (FESEM) and Raman spectroscopy.

Solubility of CO2 in an Aqueous Ammonium Based Ionic Liquid

The aim of this research is to find out the potential usage of water miscible ammonium based ionic liquids (ILs) towards CO2 capture. To measure the solubility of CO2 in 55 wt. % aqueous solution of Tetra butyl ammonium hydroxide (TBAOH), the experiments were carried out using high pressure solubility cell. Solubilities were determined in the temperature range of (303.15 to 333.15) K by varying the pressure from (2 to 10) bar and are reported as loading capacity (mol CO2/mol TBAOH). The solubility of CO2 in this aqueous IL decreased with increasing temperature and increased with increasing pressure.

Effect of Solid/Liquid Ratio during Curing Time Fly Ash Based Geopolymer on Mechanical Property

Geopolymer is produced from the alkali activation of materials rich in Si and Al such as fly ash. Based on the experimental and characterization result, solid to liquid ratio influenced the setting time and compressive strength of geopolymer in order to have good mechanical property. The optimum setting time and compressive strength were obtained at 3 : 1 solid to liquid ratio. Optimum curing time reach at 14 days.

Influence of PZC (Point of Zero Charge) on the Static Adsorption of Anionic Surfactants on a Malaysian Sandstone

Static adsorption studies of two anionic surfactants produced in our lab are reported. The adsorption of surfactants on the rock samples was investigated with and without the presence of alkali. The point of zero charge (PZC) values were determined for the sandstone samples employing three titrimetric methods and it was found to be at pH 7.98. The relationship between the adsorption degree and pH value of brine below and above the PZC is discussed. It was found that at the pH of solution exceeds the PZC of the rock, the adsorption was 0.43 and 0.86mg/g of rock for the two surfactants. However, at pH values below PZC, the adsorption as high as 3.66 and 4.49mg/g for the two surfactants. The synthesized surfactants are found to be suitable for the EOR applications at pH values higher than the PZC of the rock sample.

Effect of Solid to Liquid Ratio on the Mechanical and Physical Properties of Fly Ash Geopolymer without Sodium Silicate

Geopolymer is produced from the alkali activation of materials rich in Si and Al with addition of silicate solution in order to improve the mechanical property. Limited research has been done with the absence of silicate solution in the geopolymerization process by varying solid/liquid ratio and on how it works for that condition on mechanical and physical properties. This paper presents an investigation on the mechanical and physical properties of fly ash based geopolymer by varying solid to liquid ratio using sodium hydroxide as the only activator. In addition, the strength development also been investigated. The samples were prepared using 50mm x 50mm x 50mm mould and cured at an elevated temperature (60oC). It can be observed that the optimum compressive strength and density were obtained at solid/ liquid ratio of 4. In addition, the compressive strength of fly ash based geopolymer for all the solid to liquid ratio increased until 14 days and started to decrease later.

The Effect of Si/Al Ratio and Sodium Silicate on the Mechanical Properties of Fly Ash Based Geopolymer for Coating

The present study has been performed to see the effect of varying Si/Al ratio (1.85 to 3) by using same concentration of NaOH and same solid/water ratio for the development of mechanical properties at 28 days of room temperature and also select the Si/Al ratio for coating application. The performance of the geopolymer was investigated on the basis of compressive strengthSEM along with EDS. Pure sodium hydroxide specimens displayed decreased strength. However the combination of sodium hydroxide and sodium silicate specimen with aSi/Al ratio of 2 showed maximum strength, whereas the specimen after Si/Al ratio 2 showed decrease in strength.