Chemical Engineering

In drilling mud formulation, evaluating the mud cuttings carrying capacity provides the means of establishing its wellbore hole cleaning potential. Thus, a synthetic-based mud was formulated from derived ester and evaluated for its mud weight and rheological properties: plastic viscosity and yield point. A two level-three factors (23) full factorial design was performed to evaluate the cuttings carrying index (CCI) of the formulated synthetic-based mud. This offers the privilege of assessing the combined effect of these factors: plastic viscosity, yield point and mud weight on the cuttings carrying capacity of the mud. The factors’ levels (low and high) from the formulated mud properties measurement were 6 and 17cp, 10 and 13lb/100ft2, and 8.63 and 9.50lb/gal for plastic viscosity, yield point and mud weight respectively. Thus, the experimental design results obtained, resulted ingood cuttings carrying capacity (adequate hole cleaning) as the obtained CCI values were above 0.5. Additionally, the results further revealed main effect from the formulated mud’s rheological properties and mud weight on its cuttings carrying capacity. Furthermore, the experimental design result depicted that there was interaction effect between the rheological properties, whilst there was no interaction effect between the rheological properties and the mud weight at the considered factors’ level. Therefore, a potential synthetic-based mud with adequate wellbore hole cleaning capacity could be formulated at the considered mud properties.

This paper focus on the investigation of kinetic and thermodynamic characteristic of adsorption of Pb2+ ions unto functionalized Nigerian Ahoko Kaolin. The adsorption rate of Pb2+ onto the TPP-functionalized and the un-functionalized kaolin was found to increase from 0.479 to 1.915 and 0.340 to 1.894 (mgg-1min-1) in the first 10 min while increasing the initial Pb2+ concentration from 250-1000 mg/L. There was decrease in adsorption thereafter attaining equilibrium after 70 min. Increase in temperature from 298 to 323 k increase both the pseudo-second order reaction rate constant K2 and the initial sorption rate h on both the functionalized and un-functionalized kaolin. The values of K2 increase from 0.365 to 0.426 (mgg-1min-1) and 0.217 to 0.296 (mgg-1 min-1). The values of enthalpy obtained suggest that the adsorption process is endothermic in both material used with the functionalized kaolin showing higher endothermic behavior. The values for entropy and enthalpy are 106.40 and 33318.82 (kJmol-1) for functionalized kaolin and 109.78 and 34624.73 (kJmol-1) for the un-functionalized kaolin. The adsorption process follows a pseudo-second order reaction path.

The three-phase frictional pressure drop for gas-liquid-solid mixture secondary ?ow through helical curved pipe in vertical orientation is investigated and reported in this article. Effects of different operating variables on the three phase pressure drop are enunciated and the experimental results were analyzed and Lockhart-Martinelli and Davis model are incorporated to predict the three-phase frictional pressure drop. A correlation for parameter for the model is also proposed to predict frictional pressure drop for gas-liquid-solid mixture flow through helical curved pipe by dimensional analysis.

Nanostructured surfaces are surfaces bearing nano-sized features that have characteristic lengths ranging on a scale of a few to a few hundreds of nanometres. Nanostructuration of surfaces is considered as a promising track in many micro-thermo-fluidic applications, as it is expected to allow noticeable heat transfer enhancement or hydraulic resistance reductionis due to momentum transfer to the solid walls. This paper reviews and summaries the recent experimental and theoretical works on the pool boiling with nanostructure surfaces

This paper contains the results of a new experimental study of the temperature effect on density and ultrasonic velocity for peanut (Arachis hypogaea), canola (Brassica napus L., Brassica rapa L. and Brassica juncea) and rosa mosqueta (Rosa affinis rubiginosa L.) oils. The Halvorsen’s model (HM), and Collision Factor Theory (CFT) were selected for prediction of these properties, attending to ease of use and range of application. An accurate response was observed, despite of the use of molecular group contribution procedures for estimation of theoretical critical points and the complex nature of the studied fluids.

In this study coal fly ash (CFA) which is the waste product of coal fired power plant is used as an adsorbent for adsorption of phenol from aqueous solution in packed bed column. The effect of bed height (7.5, 13.5, 27.5 cm), effect of flow rate (0.375, 0.75 and 1.0 ml/min) and initial phenol concentration (70.0, 292.7, 651.2, 1039.9 mgL-1) on the adsorption were studied by assessing the breakthrough curve. Thomas and Yoon-Nelson models were used to evaluate the column performance. The result shows that with increase in flow rate, break point time decreases while the values of maximum adsorption capacity (q0) decreased and the Thomas constant (KTh) increased. As the bed height and initial concentration increases, break point time increases with bed height but decreases with initial concentration but q0 increased while KTh decreased. The maximum adsorption capacity was found to be 5.90 mg/g at 1.0 ml/min flow rate and 27.5 cm bed height with phenol concentration of 1039.9 mg/L. Key words: Coal fly ash, Phenol, packed bed column, adsorption, Thomas and Yoon Nelson model.

The failures of the bituminous pavements are not only due to increase in traffic but also due to extreme climatic conditions prevailing in the country. The addition of polymers to bitumen can improve the quality of binders and enhance the properties of binders used in the road construction. Bitumen ageing is one of the principal factors causing the deterioration of asphalt pavements due to the prolonged exposure to air and environmental conditions. Short-term ageing occurs when binder is mixed with aggregates in a mixing facility. Long-term ageing occurs after pavement construction and is generally due to environmental exposure and loading. The properties of bitumen mainly depend on the age of bitumen. Therefore there is a need to study the properties of modified bitumen before and after ageing. In this paper the effect of Aging on the physical properties of SBS (Styrene Butadiene Styrene) modified bitumen is discussed.

The transesterification reaction is actually replacement of alcohol group from an ester by another alcohol. The reaction was carried out by varying different parameters, like amount of catalyst in reaction, ratio of methyl alcohol to oil, temperature and stirring on the reaction; to find the best conversion of oil to biodiesel. In this paper fuzzy logic is applied to the transesterification reaction studies and the result is compared with the experimental results.

The hexavalent chromium present in waste water has adverse affect on aquatic life and humans. Various methods are available for the removal of hexavalent chromium includes chemical precipitation, ion exchange, reduction, electrochemical precipitation, solvent extraction, membrane separation, evaporation, foam separation and biosorption. Among these, biosorption is one of the low cost separation technique for the removal of chromium using agricultural waste as adsorbents which are cheap and readily available and also has the advantage of practical replacement to conventional processes. The kinetic models and adsorption isotherms for the efficient removal of hexavalent chromium are presented from various sources. The present review elaborate the findings of hexavalent chromium removal with the maximum metal uptake, adsorption parameters using agricultural wastes as adsorbents

Power generation efficiency of a DMFC depends on the concentration of methanol solution, hence analysis on the development of methanol concentration sensor is getting importance. Measurement of methanol concentration using various techniques namely MEMS, Capacitive type, Dielectric constant and piezoelectric crystal are critically analyzed in this paper. Based on the specific requirement, a particular type of methanol concentration sensor is utilized for the defined power output of DMFC.