Offshore Topside Rotating Packed Bed as Process Intensified Alternative for Natural Gas Sweetening and Dehydration

This work is aimed at investigating the benefits of replacing conventional process unit operations with process intensified ones in offshore applications. This ensures that better use is made of raw materials, lower energy consumption and a reduced plant volume was achieved. Specifically, a rotating packed bed technology has been used for gas dehydration and sweetening. To achieve the aim of this study, a process intensification approach is used to redesign mature absorption processes to more compact and efficient one. Process simulation using Aspen Hysys was carried out for Triethylene glycol dehydration and monoethanolamine sweetening. More than 36-fold absorption unit size reduction was achieved thereby effecting large decrease in capital and operating costs compared to the conventional packed columns currently utilized in the offshore oil and gas industry. The process intensified technologies therefore can be deployed for offshore applications where space and size considerations are of utmost importance

Atmospheric boundary-layer characteristics and their significance in wind energy and urban air quality assessment

The study of the Atmospheric Boundary-Layer (ABL) flow is growing rapidly, owing to its crucial role in promoting environmental sustainability and facilitating renewable energy development. The significance of ABL modeling cannot be over-emphasized due to its broad applications in air quality management, meteorology, wind energy, weather forecasting, and climatology, which directly impact human lives. This research specifically focuses on modeling the ABL characteristics and their significance in wind energy and urban air quality assessment. The purpose is to investigate how the presence of canopy structures affects the development of the ABL and their importance in areas like wind resource evaluation and air quality management. To model the ABL flow, the Computational Fluid Dynamics (CFD) tools based on Reynolds-Averaged Navier-Stokes (RANS) simulations and Large Eddy Simulation (LES) approaches were employed. The simulations used open-source codes such as the Open-source Field Operation And Manipulation (OpenFOAM) and Parallelized Large-Eddy Simulation Model (PALM). The results were validated through comparison with relevant experimental data and field measurements. The research outcome demonstrated the impacts of various forest structures on ABL development and wind-turbine wake flow patterns for wind energy applications. The outcome also has the prospect of providing insights for improving air quality in urban areas

Impact of different forest densities on atmospheric boundary-layer development and wind-turbine wake

The aim of this work is to investigate the atmospheric boundary‐layer (ABL) flow and the wind turbine wake over forests with varying leaf area densities (LAD). The forest LAD profile used in this study is based on a real forest site, Ryningsnäs, located in Sweden. The reference turbine used to model the wake is a well‐documented 5‐MW turbine, which is implemented in the simulations using an actuator line model (ALM). All simulations are carried out with openFOAM using the Reynolds averaged Navier‐Stokes (RANS) approach. Twelve forest cases with leaf area index (LAI) ranging from 0.42 to 8.5 are considered. Results show that the mean velocity decreases with increasing LAI within the forest canopy, but increases with LAI above the hub height. Meanwhile, the turbulent kinetic energy (TKE) varies nonmonotonically with forest density. The TKE increases with forest density and reaches to its maximum at an average LAI of 1.70, afterwards, it decreases gradually as the density increases. It is also observed that the forest density has a clear role in the wake development and recovery. Comparisons between no‐forest and forest cases show that the forest characteristics help in damping the added turbulence from the turbine. As a consequence, the forest with the highest upstream turbulence has the shortest wake downstream of the turbine.Post-print / Final draf

Fear of crime on the rail networks: Perceptions of the UK public and British Transport Police

Counter-terrorism on the rail network is vital to the security of the United Kingdom. The British Transport Police (BTP) employ covert and overt security measures to prevent crime, which includes: closed circuit television, armed police, unarmed polisce, police community support officers, police dogs, stops and searches and awareness campaigns. All security measures aim to deter crime while importantly reassuring the public. We surveyed both members of the public and BTP officers about the perceived effectiveness of current security measures, specifically with regards to fear of terrorism. Feelings of reassurance and the perceived effectiveness of security measures were positively related. The most effective and reassuring security measure was the use of armed police; whereas the least effective and reassuring was the use of awareness campaigns. However, interestingly, qualitative analyses suggested that an increase in armed police without informed awareness campaigns would have a negative impact on public reassurance by increasing fear

A Framework for Sustainable Maintenance of Offshore Energy Structures

This paper proposes a structure for maintenance decision support suitable for application to renewable energy assets. The method combines subjective tacit knowledge of subject-area experts with well-structured Analytical Hierarchical Process (AHP) to elicit weights of criteria relevant for effects evaluation of possible failures modes towards support for component’s maintenance decisions. The Technique for Ordered Preference using Similarity to Ideal Solution (TOPSIS) algorithm is adopted for aggregating the evaluation scores and achieving priority indexing given the conflicting characteristics of some criteria. Part of the highlights of the Framework is the implementation of the group experts, as well as individual expert's elicitations in a complimentary manner that eliminates subjective opinions and achieves a repeatable evaluation score. The conclusion of the analysis is the prioritisation of the component’s failure; An indicative case study of offshore wind turbine jacket support structure is used to demonstrate the applicability of the approach and the analysis results-which shows priority failure modes for focused maintenance intervention as bending of Chord/Brace ( ), collapse of Chord/Brace ( ), buckling of Long piles ( ), and Truss( ), overturning of Skirt pile ( ), and fatigue of Long pile ( ), further demonstrates the capacity of the model to support maintenance decisions. Caution is exercised in the selection of criteria that would capture the objectives of the risk analyses by consulting wide range of industry experts. Keywords— AHP, Expert, Offshore energy, TOPSIS, Wind turbine Support Structur

Development of a petroleum pipeline monitoring system for characterization of damages using a Fourier transform

Significant damage to the environment and huge economic losses are potential problems caused by leakage from petroleum pipelines. The occurrence of a leakage in a pipeline throughout its lifetime is very difficult to prevent. To minimize environmental damage and high economic losses, an efficient pipeline monitoring system is required to carry out damage characterization thereby enhancing quick response. The signal processing technique of sampling and reconstruction was adopted and mathematical algorithms for the characterization of damages in pipes were developed using the Fourier transform method. These were simulated with the results showing a good agreement between the shapes and magnitudes of the measured original and reconstructed pulses. The simulation was verified with experiments on the test rig. The results showed an underestimation in the magnitudes of the reconstructed pulses in the range of 40 – 45 %. This problem was solved by using a factor K obtained by dividing the maximum amplitude value of the original pressure pulse by that of the reconstructed pulse. Reconstruction of the measured original pulse at a damage location was achieved from combining the measured pulses from two other close locations using the developed Fourier transform based model. Keywords: Damage Pipeline-monitoring Characterization Fourier transform Reconstructio

Geological Characterization of Azara Barite Mineralization, Middle Benue Trough Nigeria

The Azara Barites Mineralization in The Middle Benue Trough Occurs as Vein Infilling Materials associated with Lead-Zinc Lodes. A Fracture Formed as Single Linear Structures with thickness of  generally not more than 0.5m. The Geological Characterization of The Azara Barite Deposits which Include; Geotechnical, Petrological And Geochemistry Were Studied Within The Four (4) Selected  Veins Samples: V1 N (08020’40.6’’) E (0090 17’21.3’’) V 12 N(08021’59.0’’) E(009021’13.6’’) V13 N(08021’44.0’’) E (009021’14.6’’) V17 N(08022’27.1’’) E(0090 17’31.7’’). Soluble Alkaline Earth Metal Test (100mg/L) Indicate Presence of Calcium or  Magnesium which is Good for  Drilling Fluid, Hardness Capacity of  the Veins Mineralization ranges From 3.0 to 3.5 with an average Specific Gravity of 4.2. this classify the Veins as a High Grade Barite. Fluid Performance was Measured based on Yield Point and Plastic Viscosity which is high even at aging and at high Temperature. Quantitative Mineralogical Analysis reveals Barite as the Main Mineral with an  average  of 92 Wt.%   and Quartz as an associated Minerals with average  of  8wt.%.The Mineralogy revealed a Mineralization with One of the purest Veins and less  Number of Impurity, the Colour Index  Criteria also classify the Veins to be Melanocratic (60-90).The Elemental Composition of the Veins show  classes of Major Elements with average weight Percentage of greater than 1% (Sio2, SO3, Bao , Sro,) also  reveal  the Veins Are Oversaturated Based on The Composition of Sio2 And Metaluminous Group ( K2O+Na2O+Ca2>Al2O3>Na2O+K2O) With Modal Minerals Of Feldspar and Normative Minerals of Anorthite + Diopside. These have contributed to the grade and value of Azara Barite Mineralization Veins  and its Purity and Quality for Exploration Purposes. Keywords: Barite, Mineralization, Quartz,Benue Trough,Petrology,Veins,Azar

Geoelectric Investigation Of Araromi Area Of Akure, Southwestern Nigeria

Geoelectric resistivity sounding has been carried out at Araromi area, Akure, southwest Nigeria, an area underlain by Basement complex rocks. Eighteen wenner vertical electrical sounding were carried out along six traverses. Three geologic units which are Topsoil/Laterite, weathered Basement and fresh Basement were identified. Isopach, corrosivity, total longitudinal conductance, iso-resistivity and coefficient of anisotropy maps were generated from the combination of the first and second order geoelectric parameters. Isopach map of overburden revealed bedrock depressions, which serve  as groundwater collection center. The longitudinal conductance map enabled the classification of the area into zones of good (0.7-1.0),moderate (0.2-0.65) an weak protective capacity(0.15).The results not only reasonably provide a basis for which groundwater potential zones were appraised for safety in case industrial facilities are planned for the area but also present environmental factors that should be considered at planning stages of residential and industrial estates. Key words:Geoelectric,Resistivity,Sounding,Parameters,Basement,groundwater,Environmental

Investigation of the Mechanical and Microstructural Properties of Welded API X70 Pipeline Steel

The mechanical properties of pipelines particularly those in marine environments are influenced by corrosion activity of seawater throughout their service lives. The degree to which these properties are influenced in seawater compared to those exposed to air needs to be better understood. In this study, the chemical composition of API X70 pipeline steel plate, microstructure and mechanical properties of the welded joints of same steel plates exposed to ambient air and seawater respectively were investigated. It was found that the base metal consisted of manganese (0.51wt% Mn), low carbon content (0.051 wt% C) and small quantities of alloying elements such as vanadium (0.021wt% V), molybdenum (0.118 wt% Mo), chromium (0.240 wt% Cr), copper (0.002 wt% Cu), and a carbon equivalent (CE IIW) of 0.38. Scanning Electron Microscope (SEM) showed that the microstructure of base metal sample has large grains formed in packets which have certain crystallographic orientation but contain submicron grains arranged in a chaotic interlocking manner. The tensile tests performed using a UNITED type universal testing machine confirmed that the yield strength of the base metal was 573.045MPa which conforms to API standard for X70 steel pipe. The manual metal arc (MMA) welding technique was applied to produce the welded joints.  For the welded joints exposed to ambient air at room temperature, the yield strength was 680.624MPa while the compressive strength was 1500.2MPa, and the impact energy at -10°C was 112.68J. Air tests referred to tests conducted in the laboratory at room temperature. For the welded joints exposed to seawater for 12 weeks, the yield strength was 609.154MPa while the compressive strength was 1219.34MPa, and the impact energy at -10°C was 61.48J. The above results for air and seawater exposures were used to determine the environmental reduction factors of the two environments.  Hardness tests conducted using Vickers hardness tester revealed variations in hardness across the base metal, the HAZ and the weld, with the weld having the highest average Vicker’s hardness value (223.8HV) followed by the base metal (217.3HV) and the HAZ had the least (214.5HV