Effect of Design Parameters on The Separation Efficiency of Vertical Gas/Liquid Separator in Oil Gas Pipeline

The main objective of this work is to size a vertical axis gas liquid separator to separate gas and liquid on a long distance in gas-liquid pipelines. This is necessary to ensure the safe operation of the compressors used along the pipelines.The separator equipped with wave plate demister (vane pack) as the secondary separator.The design is achieved through investigation of the parameters which has an effect on the separation efficiency of the separator. In this study, inlet pipe diameter, vessel bend spacing, vane pack bend angle, momentum breaker, vane pack plate spacing, and the number of bends in pack were used. From the results of this study overall separation efficiency of 99.99% has been achieved

Characterization Of oil/ gas flow pattern in vertical pipes using electrical capacitance tomography

Electrical Capacitance Tomography provides the opportunity to visualize the contents of a process of many applications such as pipeline and obtain information on the flow configuration. Multiphase flow is an extremely complex field of fluid mechanics; the characteristics of the operations of many equipmentin different areas of industry such as oil and power generation are determined by the nature of flow of two phase or multiphase. In this study, a twin plane Electrical capacitance tomography (ECT) electrode was designed, fabricated and used to image and characterize oil/gas flow in 67 mm pipe. The experiments were carried out in inclinable facility in the Department of Chemical Engineering at Nottingham University, UK. Conditions used are gas superficial velocities of 0.05 to 5.52 m/s and liquid superficial velocities of 0 to 0.54 m/s. The cross-section averaged void fraction and its variation in time were measured using electrical capacitance tomography. Also, Probability Density Functions are demonstrated and the structure velocity of flow is presented as well. In this project, Bubbly, slug, and churn flow configurations was observed. In addition, high speed video images of flow were obtained simultaneously and compared with tomographic images of the ECT system

Investigation in Gas-Oil Two-Phase Flow using a Differential Pressure Transducer and Wire Mesh Sensor in Vertical Pipes

The current study is performed to identify the flow regimes of oil-gas two-phase flow experimentally in a vertical pipe has an internal diameter of 6.7 cm. It also aims to provide more details about the possibility of using Differential Pressure Transducers (DPT) for indicating flow patterns. A flow development of oil and gas has been investigated in a vertical pipe of 6 m in length and operated at atmospheric pressure. A series of experiments have been run to cover a range of inlet oil superficial velocities from 0.262 to 0.419 m/s, and inlet gas superficial velocities from 0.05 to 4.7 m/s. Wire Mesh Sensors (WMS) have been used to collect the obtained void fraction values of the flow. The Differential Pressure Transducer (DPT) is utilized to measure the pressure drop values of a one-meter along the pipe. The flow patterns are classified according to the analysis of void fractions, pressure gradients regarding time series, tomographic images, probability density functions of the void fractions, and pressure gradients. A bubbly flow is observed at low superficial velocities of gas and liquid, slug flow is observed at the lower flow rate of liquid and moderate flow rates of gas, while the churn flow pattern is recognized at the higher rates of liquid and gas. Also, the result has revealed the possibility of using Differential Pressure Transducers (DPT) to classify the gas-oil flow patterns in vertical pipes

Experimental Investigation of Two-Phase Flow Patterns in a Vertical to Horizontal Bend Pipe Using Wire-Mesh Sensor

The air-water two-phase flow plays an important role in many applications of industry fields. Usually, a 90-degree bend is used to connect pipes for changing the direction of flow which influences the two-phase flow pattern. In this paper, the effect of 90-degree bend under different ranges of gas and liquid superficial velocities on the two-phase flow patterns in the horizontal pipe located after the bend was experimentally investigated, and then results were presented and compared in a two-phase flow pattern map. Also, tomographic images and probability density functions were used to capture the cross- section void fraction and its distribution for the two-phase flow patterns. The results revealed that at low liquid and gas flow rates, a stratified-wavy flow pattern was observed as a dominant flow pattern. While the wavy-annular and semiannular flow patterns were observed at a high range of gas flow rates in the horizontal pipe. The results also showed that at the high range of liquid flow rate, bubbly, plug, slug, stratified-wavy, and wavy-annular flow patterns were observed in the horizontal pipe when the gas flow increased. The tomographic images and probability density functions gave good agreement with the experimental observations and results

CFD Simulations and Experimental Observation for Air-Water Two-phase Flow in a Vertical Pipe

Air-water two-phase flow development in a vertical pipe has been investigated through service of experiments and simulations in this research. Differential Pressure Transducers (DPTs) and Wire Mesh sensors (WMSs) are used to monitor the two-phase flow in a vertical pipe of 67 mm inlet diameter and 7000 mm length. Computational Fluid Dynamic (CFD) is used to evaluate the experiments of the air-water flow in the vertical pipe using a volume of fluid (VOF) model. The operating conditions cover a range of inlet air superficial velocities from 0.05 to 5 m/s. The inlet water superficial velocity remains constant at 0.2m/s and 0.4 m/s for all experiments. The results show that the bubbly flow is noted at low superficial velocities of gas, slug flow is observed at the moderate flow rates of gas, while the churn flow pattern is observed at high rates of gas. There is no significant effect when the Usl changed from 0.2 m/s to 0.4 m/s on the vertical flow lines. Pressure drop is recorded and compared with the CFD simulations. The CFD results are over estimation compared with the experimental pressured drop with maximum absolute error of 21% at Usl of 0.2 m/s and 25% at Usl 0.4 m/s

Production of renewable diesel from Jatropha curcas oil via pyrolytic-deoxygenation over various multi-wall carbon nanotube-based catalysts

Jatropha curcas is a highly toxic plant that produces seed containing viscous oil with productivity (2 ton/ha), it grows in tropical and sub-tropical regions and offer greater adaptability to a wide range of climatic and soil conditions. Its oils have been noted as an important alternative to produce green diesel via deoxygenation reaction. This study, deoxygenation of jatropha curcas oil (JCO) was carried out over NiO–Fe2O3 and NiO–ZnO catalysts that supported onto multi-walled carbon nanotube (MWCNT). It had found that high Fe and Zn dosages were ineffective in deoxygenation and greatest activity was observed on NiO(20) Fe2O3(5)/MWCNT catalyst. Structure-activity correlations revealed that low metal loading, large density of weak + medium acidic sites and strong basic sites play key role in enhancing the catalytic activities and n-(C15+C17) selectivity. Comparing carbon nanostructures and carbon micron size supported NiO-Fe2O3 revealed that green diesel obtained from NiO–Fe2O3/MWCNT catalysed deoxygenation had the highest heating value and the lowest amounts of oxygen content. Thereby, it confirmed the importance of carbon nanostructure as the catalyst support in improving the diesel quality. Considering the high reusability of NiO-Fe2O3/MWCNT (6 consecutive runs) and superior green diesel properties (flash point, cloud properties and cetane index) demonstrated the NiO–Fe2O3/MWCNT catalyst offers great option in producing excellent properties of green diesel for energy sector

The control and maintenance of desired flow patterns in bends of different orientations

Multiphase flows are common in industrial settings and bends in pipe lines cannot be avoided due to space limitations. Gas-liquid two phase flows could form material discontinuities that could have adverse effect on productivity and the pipe network due to sudden variations resulting due to the rapid momentum flux variations at fittings such as bends. Research into gas-liquid flow and bends can be motivated by the effect of the bend on the flow downstream of it which could alter the flow pattern occurring and the performance of downstream equipment. Alternatively, the interest might come from what occurs in the bend itself, there could be dryout of the film on the walls and consequent damage to the heat transfer equipment. Here we present measurements made with a number of accurate and fast responding sensors on three cases, two on the effect of the bend and one considering effects in the bend. The results show that the flow transformations occur in two phase flows depending on the orientation of the bend and the change could be captured using fast sweeping measurement techniques. We present the evidence of effectiveness of several types of measurement techniques that could fit into various combinations of phases. The results, point to how to achieve certain flow patterns. Also recommendations are provided regarding the position of any sensor installed to determine flow pattern

Persistence of frequency in gas–liquid flows across a change in pipe diameter or orientation

From a study of the characteristics of structures across a 67/38 mm sudden contraction, using air/silicone oil flows, it has been found that frequencies of the structures (mainly slugs) persist across the contraction. This is in contrast to the velocities and lengths which increase as they move into the smaller diameter pipe. These observations were found for both vertical and 5° upward orientations. A similar persistence of frequency has been found from four other sources in the literature: a vertical (gradual) contraction; a horizontal Venturi; and two cases of horizontal pipe, 90° bend and vertical riser combination. The latter were at two contrasting conditions: (i) at atmospheric pressure with air/water in small diameter (34 mm) pipes; (ii) at 20 bar in larger diameter pipes (189 mm) using nitrogen and naphtha

Experimental comparison between wire mesh and electrical capacitance tomography sensors to predict a two-phase flow behaviour and patterns in inclined pipe

Two-phase flow behaviour and its flow patterns have a significant effect in many applications in industry. Oil-gas is one of the two-phase flow types that have many applications in petroleum and power stations. An oil-gas two-phase flow behaviour and flow patterns have been investigated in an inclined pipe using two different tomography sensors: Wire Mesh sensor (WMS) and Electrical Capacitance Tomography (ECT). A special experimental facility was designed and built to operate the tow-phase flow application in the inclined pipe with the various angle of inclination. A set of experimental data were collected using operating conditions which covered a two-phase flow range of superficial velocity of gas (Usl) from 0.05 to 0.52 m/s and superficial velocity of liquid (Usg) from 0.05 to 4.7 m/s at atmospheric pressure and room temperature. Three inclined angles to change the pipe’s inclination 45, 60, and 80-degree were applied in the experiments. The Comparison between the Wire Mesh Sensor (WMS) and Electrical Capacitance Tomography (ECT) was completed experimentally. The results revealed that there is a good agreement between the two sensors, however; the WMS had a higher frequency which was calculated 1000 frames per second compared with the ECT which worked at 200 frames per second

Characterization Of oil/ gas flow pattern in vertical pipes using electrical capacitance tomography

Electrical Capacitance Tomography provides the opportunity to visualize the contents of a process of many applications such as pipeline and obtain information on the flow configuration. Multiphase flow is an extremely complex field of fluid mechanics; the characteristics of the operations of many equipmentin different areas of industry such as oil and power generation are determined by the nature of flow of two phase or multiphase. In this study, a twin plane Electrical capacitance tomography (ECT) electrode was designed, fabricated and used to image and characterize oil/gas flow in 67 mm pipe. The experiments were carried out in inclinable facility in the Department of Chemical Engineering at Nottingham University, UK. Conditions used are gas superficial velocities of 0.05 to 5.52 m/s and liquid superficial velocities of 0 to 0.54 m/s. The cross-section averaged void fraction and its variation in time were measured using electrical capacitance tomography. Also, Probability Density Functions are demonstrated and the structure velocity of flow is presented as well. In this project, Bubbly, slug, and churn flow configurations was observed. In addition, high speed video images of flow were obtained simultaneously and compared with tomographic images of the ECT system