Evaluation of wind energy potential in the south-south geopolitical zone of Nigeria

This study examined wind energy potential of six selected locations the South-South geopolitical zone of Nigeria using 10 year wind data obtained at a height of 10m as a possible location for energy generation from wind. The obtained data showed that the annual mean wind speed for Asaba, Benin, Calabar, Port Harcourt, Uyo, and Warri were 3.3m/s, 3.3m/s, 4.4m/s, 3.4m/s, 3.5m/s and 3.7m/s respectively, with corresponding mean power density of 21.8W/m2, 21.4W/m2, 35.8W/m2, 23W/m2, 25.2W/m2, and 30.8W/m2.. The mean energy output of 183.4KWh/m2, 205.4KWh/m2, 311.7KWh/m2, 200.9KWh/m2, 220.9KWh/m2, and 274.3KWh/m2 were found for the respective locations. The corresponding annual mean wind speed with maximum energy ranged from 4.1m/s to 4.4m/s with Calabar station found to be the most suitable site for the installation of wind turbine for power generation. The overall mean wind power densities and the annual mean power densities were under class 1 of wind classification scheme indicating that, the mean wind speed fell short of required standard of 6m/s for large-scale installation of wind energy generation. Nevertheless, the power generated could be improved using suitable wind turbines at reasonable heights.Keywords: Mean wind speed, Wind power density, Wind energy, Renewable energ

MODIFICATION OF BLADE CHORD INFLUENCE ON THE PERFORMANCE AERODYNAMICS OF VERTICAL AXIS WIND TURBINES

Performance aerodynamics of VAWTs is given important considerations whenchoosing design parameters for the manufacturing of VAWT to effectively and efficiently perform after installation. Blade chord is amongst the many design parameters that can affect the CP of VAWTs in relation to wind harvest and energy yield. This study examines the influenceblade chord modification can have on the PA of wind turbines. The VAWT blade chord of NACA0022 was modified and two configurations of rotors, one with C = 0.03m and the other of C = 0.04m were tested in a low speed and low turbulent intensitytunnel at several wind speeds. An appropriate performance measuring techniques was used to conduct the tests on the two VAWT configurations. The results showed substantial differences in the measured performance efficiency of the two configurations. The two rotorsreached peak performances at the highest tested freestream speed of 8 m/s. The VAWT configuration of C = 0.04m attained higher performance with peak CP = 0.326 at λ = 3.75 while the C = 0.03m showed lower peak CP = 0.26. Changes in the CPwere seen in relation to changes in the free wind speeds.Also the peakperformanceschanged positively as the wind speed is increased. The curves of plot of the CP - λ is observed to close up at region of the peak performances. The CP, the performance efficiency and aerodynamics of the two rotors and configurations are shown tohave been visibly affected bythe modification of the blade chord

INVESTIGATING THE SUITABILITY OF A TWO DIMENSIONAL SMALL SIZE VERTICAL AXIS WIND TURBINE NUMERICAL MODEL

This paper aims at the determination of the suitability of applying a numerical model of a VAWT for research purpose. A CFD two-dimensional model was created and simulated with fluent code software while the forces and flow field data were monitored and obtained. The data were compared with the experimental data obtained from a wind tunnel test. Data comprised forces and flow field velocity of a similar sized VAWT were experimental obtained in a wind tunnel, through suitable VAWT performance measurements and particle image velocimetry techniques. The suitability procedure was initiated with a static aerofoil study that reduced five fully turbulence models to one by the comparison of the fully turbulence models against experimental data at Reynolds number of 1.35x105. The Transition SST and SST k-w models data sets of VAWT model were thereafter compared to the force and PIV experimental data of similar scaled VAWT obtained in a wind tunnel. The force and flow physics verification and validation show the Transition SST turbulence model as the most appropriate model for CFD modelling at the Reynolds numbers of 1.27x103, thus confirming that numerical methods are valuable tools that can be used in conducting research in VAWT

Assessing yield and properties of distillate from biocrude and blend after hydrothermal liquefaction of microalgae

This paper is on assessing yield and properties of distillate derived from biocrude, and blend stream of biocrude and conventional petroleum. Biocrude was produced from hydrothermal liquefaction of a halophytic microalga Tetraselmis sp. at 350oC, 5min with 16w/v% solids content. The resultant biocrude was coprocessed with petroleum using fractional distillation. The result of the study shows that similar yield and quality distillate were obtained from petroleum and blended stream. Distillate fraction obtained from the blend had similar properties such as higher heating values (HHV), H/C atomic ratio and elemental composition to those of petroleum crude. The energy density of biocrude-distillate significantly improved from 72.4MJ/kg to 86.9MJ/kg with about 97% reduction in oxygen content. Recovery of gasoline fractions with normal boiling point range of 190oC to 290oC were found higher in petroleum and blend compared to biocrude. This finding is important as coprocessing blend of biocrude and petroleum would address the issues with heteroatoms, which could be of great economic importance. However further studies are necessary on distillate fractions, in order to assure compatibility with petroleum derived fuels.Keywords: Biocrude; Coprocessing; Microalgae; Hydrothermal liquefactio

Effects of separation methods on yield and quality of biocrude after thermochemical liquefaction of marine microalgae

Hydrothermal liquefaction (HTL) is a promising process for conversion of microalgae to biocrude that is upgradable to liquid transportation fuel. However, there is yet to be established standard separation method for product recovery. In this paper, the effects of separation methods on yields and quality of biocrude were investigated. HTL studies were conducted at operating conditions of 350oC and 5min with solids loading of 16wt%. The results shows that multistep extraction of product mixture led to ~65wt% biocrude yield compared to ~48wt% for single step. Multistep extraction led to increase in biocrude yield, with lower yields in solid residue and aqueous phases. However with the trade-offs of nitrogenous and oxygenated compounds in biocrude. Quality of biocrude was improved after vacuum evaporation of biocrude phase at 100oC when compared to evaporation at 40oC. The separation methods had little impact on biocrude energy density, which varies between 34MJ/kg and 38MJ/kg, 1.5 and 1.7 for hydrogen-to-carbon atomic ratios.Keywords: Biocrude; Energy; Hydrothermal liquefaction; Microalgae; Separation method

Production and analysis of biodiesel from Jatropha curcas seed

This present reported work was conducted to extract oil from Jatropha curcas seed, followed with the production of biodiesel via transesterification of resultant oil. The effects of methanol-to-oil ratio 1:1, 2:1, 3:1, 4:1, 5:1 and 6:1, reaction time of 30, 60, 90, 120 and 180min, at constant operating temperature of 60oC were investigated. Also the energy input required for production of a unit biodiesel was calculated. The results of the study shows maximum biodiesel yield of 86wt% at methanol-to-oil ratio of 6:1, at reaction time of 180min. An energy input of ~1.4MJ/kg was estimated to produce a unit biodiesel from Jatropha curcas. The data reported in this study would improve fundamental knowledge in biodiesel production from Jatropha curcas seed as a renewable energy to complement fossil fuel.Keywords: Biodiesel; Jatropha curcas seeds; Jatropha oil, Mass and Energy balance; Transesterificatio

Elucidation of Sodium Hydroxide Catalyst and Solids Loading for Thermochemical Liquefaction of Tetraselmis sp. Microalga

The production of biocrude with and without sodium hydroxide catalyst (Na2CO3) through hydrothermal liquefaction of Tetraselmis sp. microalga at different organic solids loading was investigated. The HTL experimental study was conducted at reaction temperatures of 310oC, 330oC, 350oC and 370oC at 5 min fixed reaction time with organic solids loading of 10%w/w, 15%w/w, 20%w/w, 25%w/w, 30%w/w, and at 40%w/w. The results of the study showed that organic solids loading above 20%w/w had no substantial changes on biocrude yield. The catalyst had very little effect on the yield of biocrude but substantially enhanced its quality when compared with non-catalysed reactions. Although, Na2CO3 catalyst may be used for HTL of Tetraselmi sp. in laboratory-scale studies, it is highly unnecessary for commercial-scale. Thus potentially reducing the production cost in future commercialization of HTL-alga-biorefinery. Keywords: Biocrude, Na2CO3 catalyst, hydrothermal liquefaction, Microalga, organic solids loadin

Statistical analysis of the physical properties of varieties of beans (Phaseolus vulgaris L.) influenced by maturity stage

Physical properties of post-harvest bean seeds was studied, but the physical properties of bean seeds in response to post flowering (maturity stage) have not been fully studied; therefore, this study is aimed at evaluating the physical properties of two bean varieties (iron and honey) during their maturation stages. The bean seeds were harvested at 15, 20 and 25 days after flowering (DAF), the physical properties (length, width, thickness, average thousand seed mass, size, volume, geometric mean, sphericity, surface area, arithmetic mean, bulk density, true density, porosity, angle of repose, and the static friction coefficient (against plywood, rubber, Formica, galvanized iron, and aluminum surfaces)) in both bean varieties were evaluated. The results showed that maturity stage of the bean seeds significantly (P≤ 0.05) influenced all their physical properties. Over the course of a maturation time, while their porosity and angle of repose decreased, in both bean varieties, other properties were found to increase. The bean seeds true density increased from 817.75 to 1207 kg/m3 in iron bean, and 774.25 to 1144 kg/m3 in honey bean; likewise, the bulk density increased from 464.5 to 761.75 kg/m3 and 544.75 to 867.66 kg/m3 in the iron and honey bean respectively; porosity decreased from 42.15 to 36.37% in the iron bean and 34.19 to 26.41% in the honey bean. The static coefficient of friction result was; Formica (iron bean, 0.24 to 0.35; honey bean 0.22 to 0.28), aluminum (iron bean 0.31-0.37; honey bean 0.25 to 0.32), galvanized iron (iron bean, 0.35-0.44; honey bean, 0.33 to 0.39), plywood (iron bean, 0.49 to 0.58; honey bean 0.39 to 0.46), and rubber (iron bean 0.55 to 0.61; honey bean 0.43 to 0.50). While the angle of response decreased from 39.62 to 30.73o in the iron bean and 45.78 to 36.84o in the honey bean. Furthermore, the results show that the ideal period for harvest, processing and handling of the two bean seeds is 20 to 25 days after anthesis, since the seeds will be having maximum dry weight and higher viability. Data gotten from this result is useful in the design and development of harvesting, handling and processing equipment.Keywords: Iron bean, honey bean, physical properties, maturation, moisture conten

Jurisdiction of the international Criminal Court: Analysis, loopholes and challenges

One of the most fundamental questions of law is whether a given court has  jurisdiction to preside over a given case. Jurisdiction is a critical legal issue  underpinning the prosecution of offenders of international crimes envisaged by the  International Criminal Court(ICC). The ICC must establish proper jurisdiction to  assert judicial and penal authority over such offenders, especially if they are not  citizens of State Parties to the Rome Statute and the crimes they committed were  not committed in the territory of a State Party to the Rome Statute. The issue of  jurisdiction can act to delimit permissible legal responses by concerned  governments or the international community to international crimes. As a result of  hard negotiations, it was agreed that the Rome Statute prohibits the criminal  responsibility of persons for conduct prior to the statute’s entering into force; ICC  may exercise jurisdiction when the crime is committed in the territory of the  member State to the Rome Statute or when the perpetrator is national of the  member State, or when the situation in question is referred to the court by the  United Nations Security Council (UNSC) or when a Non-Party State ad hoc accepts  the court’s jurisdiction. However, this paper argues that the basis of the ICC  jurisdiction creates possibilities for perpetrators of core international crimes to go unpunished contrary to the Preamble of the Rome Statute that such crimes must not go unpunished.Key words: International Criminal Court, Jurisdiction, International Crimes, State Party and Non-State Party

The pre-trial procedures and principles of the International Criminal Court

Following the heinous cruelties perpetuated by the Nazi regime during the World War II, the world was baffled by the expanse of brutality human beings could commit against one another. However, there was absence of a universal acceptable international criminal procedural structure to try perpetrators of the atrocities. The consequent Nuremberg criminal proceedings were undertaken based on her own rules of evidence; no acceptable laid down procedure and principles; charges against the accused persons were done ex-post facto and devoid of any country’s law. The subsequent atrocities in former Yugoslavia and Rwanda in 1993 and 1994 respectively which in turn led to the establishment of the International Criminal Tribunal for the former Yugoslavia (ICTY) and International Criminal Tribunal, Rwanda (ICTR) engineered a positive nod that an international criminal court with attendant procedural provisions was indeed needed to urgently address the escalating issues of atrocities in the international community. Despite the creation of the ICC with attendant procedures and principles and commencement of operations sometime in 2002, legal experts, public affairs analysts and media personnel are yet to appreciate the workings of the ICC. The issues on the pre-trial procedures and principles of the ICC, appears regularly in the literature, media and have entered the public domain, yet it is still not easy to comprehend. At first glance, the sheer number of these publications seems discouraging, in that it might be assumed to confuse than inform. Against this background, this paper attempts to put the ambiguities aside and critically examine the pre-trial procedures and principles of the ICC.Keywords: Jurisdiction, International Criminal Proceedings, Pre-Trial Procedures and Principles, Complementarity, Confirmation of Charge