Identification and optimization of biosurfactant producing bacteria isolated from rag layer crude oil emulsion

Biosurfactants are surface active compounds that synthesized as secondary metabolite by wide range of bacteria and have characteristic in lowering surface and interfacial tension. This study aimed to isolate and identify biosurfactant producing bacteria from rag layer crude oil emulsion. Rag layer is considered as undesirable material as it is difficult to be separated because of the stable interaction between different components. Mineral salt medium supplemented with glucose and crude oil was used to screen the ability of isolates to produce biosurfactant. Five bacterial strains that successfully isolated from rag layer crude oil emulsion sample were screened for hydrocarbon degradation and biosurfactant production. Two isolates shown positive results in drop collapse test, surface tension measurement and emulsification index, namely P3b and P4. 16S rRNA analysis revealed P3b and P4 to be closely related to Enterobacter xiangfangensis while P4 was Shewanella chilikensis, respectively. Only isolate P3b was selected for further study. Enterobacter xiangfangensis SSP3b16 was found to grow optimally at 37°C, pH 7.0 and 10mM glucose. The highest reduction of surface tension was recorded when culture medium supplemented with 7 % (v/v) glucose and 2 g/L ammonium nitrate. From this study, the biosurfactant production by Enterobacter xiangfangensisSSP3b16 can potentially be exploited to enhance oil recovery as well as in solving the rag layer problem in oil industries

A decade after the tsunami: preliminary exploration deposit layer of sediment at coast area of Kedah, Malaysia

Study on tsunami deposits is done after a decade of the incident happened at Kedah, Malaysia. This article discusses the characteristics, measurement and thickness of tsunami deposits. It also provides the latest remaining evidences of the tsunami incident including imbrication pattern of cobbles, types of coastal protection and plants at the affected area. Run-up heights and inundation distance were taken into account for field exploration and investigation. This study may provide opportunities to understand how remaining evidences of tsunami could be tracked and recorded

EFFECTS OF DRILLING MUD CONTAMINATION ON THE PROPERTIES OF WAXY CRUDE OIL

Contamination of crude oil with drilling mud normally occurs during drilling process. The contamination may change the properties of crude oil leading to inaccurate assessment of the first extracted crude oil. Incorrect prediction of crude oil properties and behavior will subsequently lead to under- or over-designing of the upstream and midstream facilities. Therefore, the work aims to investigate the effects of drilling mud contamination on waxy crude oil properties such as pour point temperature, wax appearance temperature (WAT) and the yield strength of the waxy crude oil gel. Measurements conducted on the drilling mud contaminated mixture show no effect on the pour point, minimal changes to the WAT and considerable increase to the viscosity and yield stress values. Bottle test results indicate that drilling mud free oil layer which should be used in characterizing the crude oil exist only after 24 hours of gravity settling

Microstructural properties of glass composite material made from incinerated scheduled waste slag and soda lime silicate (SLS) waste glass

Glass composite material (GCM) was produced from incinerated scheduled waste bottom slag (BS) and soda lime silicate (SLS) waste glass. The effect of BS waste loading on the GCM and the microstructural properties was studied. Batches of powder mixture is formulated with 30 wt.% to 70 wt.% of BS powder and SLS waste glass powder for GCM sintering. The powder mixtures of BS and SLS waste glass were compacted by uniaxial pressing method and sintered at 800 °C with heating rate of 2 °C/min and one hour soaking time. The phases identified by X-ray diffraction (XRD) method in all sintered samples are anorthite sodian, quartz, hematite and diopside. It was observed that higher BS waste loading results in higher porosity, higher water absorption and lower bulk density according to ASTM C373. In contrast, the Vickers microhardness value determined according to ASTM C1327, decreases with higher BS waste loading. This similar trend is observed for modulus of rupture (MOR) analysis which was performed according to ISO 10545-4. This physical and mechanical properties can be related to the microstructure observed during scanning electron microscope (SEM) analysis. More open pores and less dense surface are observed for higher BS waste loading samples. On the other hand, samples with lower BS waste loading consists of higher dense surface and no open pores. GCM with batch formulation of 30 wt.% BS and 70 wt.% SLS waste glass has shown the lowest water absorption percentage of 1.17%, the lowest porosity percentage of 2.2% and the highest bulk density value of 1.88 g/cm3. It also shows the highest MOR of 70.57 MPa and 5.6 GPa for Vickers microhardness with congruent microstructure features

Mean induction time and isothermal kinetic analysis of methane hydrate formation in water and imidazolium based ionic liquid solutions

In this work, the performance of nine ionic liquids (ILs) as kinetic inhibitors for methane gas hydrates is investigated employing a high pressure micro differential scanning calorimeter (HPμDSC). Aqueous IL solutions of 0.01mass fraction, as well as poly vinyl pyrrolidone (PVP), are prepared and the induction time of methane hydrate formation in these solutions is measured at 7.1MPa and 258.15K. It is found that [BMIM][CF3SO3], [BMIM][CH3SO4], and [OH-EMIM][Br] can delay hydrate formation at this concentration. Their relative inhibition power (RIP) are higher than PVP. The other ILs exhibit shorter induction time when compare with the blank sample, which shows their promotional effect rather than inhibition effect. It is found that there is a strong correlation between molar mass of [BMIM]+ based ILs and induction time. An attempt to model the kinetic of methane hydrate formation in the presence of low dosage ILs has been carried out using Avrami model by utilizing isothermal hydrate crystallization data. The kinetic analysis shows the needle like the shape of the nuclei and the one dimensional crystal growth during the methane hydrate formation. The Avrami analysis also indicates that most of the crystallization process of methane hydrate is governed by the enclathration reaction and slightly leads by the diffusion-controlled mechanism

Intelligent classification of waxy crude oil odor-profile at different temperature

Crude oil is one of the basic needs required for humans to ease their life. The quality of crude oil with the lowest wax content is very important, in order to sustain the transportation and production of crude oil from offshore to onshore. Based on literature from previous studies, the appearance of wax depends on the temperature which is called Wax Appearance Temperature (WAT). Hence, there is a need to propose a new method to classify the waxy crude oil at a different temperature. The main purpose of this paper is to classify Malaysian waxy crude oil odor profile at different temperatures using intelligent classification technique. There are 28,000 data measurement of the waxy crude oil that was taken using an electronic nose (E-nose). The data readings have been normalized and analyzed using a statistical method. Then, the odor profiles were classified using K-Nearest Neighbour. The classification performance shows that the technique was able to classify the Malaysian waxy crude oil odor profile at different temperatures with 100% accuracy

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.</jats:p