Browsing by Author "Ighalo, Joshua O."

Now showing 1 - 7 of 7
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    Computer aided modelling of low density polyethylene pyrolysis to produce synthetic fuels
    (Nigerian Journal of Technology (NIJOTECH), 2018-10-01) Adeniyi, A. G.; Eletta, O. A. A; Ighalo, Joshua O.
    The pyrolysis of waste low-density polyethylene (LDPE) is an excellent method of converting waste materials into useful products. Aspen HYSYS 2006 was used to develop a computational steady-state model to simulate the pyrolysis of LDPE. The Peng-Robinson fluid package was used for the simulation. A continuous stirred tank reactor with an Arrhenius kinetic expression was used to predict reaction extent and product yield. At a pyrolysis temperature of 4500C and atmospheric pressure, 92.88% liquid yield was obtained. From the given feedstock, the char obtained was composed of only elemental carbon. The synthesis gas was composed mainly Hydrogen and C1-C4 hydrocarbons with traces of n-C5 and n-C6. The Pyrolysis oil was composed of higher hydrocarbon fractions (C8-C24). The conversion-temperature relationships from the simulation are in good agreement with experimental results. This proved that pyrolysis of waste LDPE can give an excellent yield of liquid product and is a viable recycling technique.
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    Computer aided simulation of the pyrolysis of waste lubricating oil using Aspen Hysys.
    (Journal of Environmental Research, Engineering and Management, 2018-02-01) Adeniyi, A. G.; Adewoye, L. T; Ighalo, Joshua O.
    The pyrolysis of waste lubricating oil is an exciting technique of converting waste materials into useful products by thermal decomposition at elevated temperature under inert conditions. Aspen HYSYS 2006 was used to develop a computational steady-state model to simulate the pyrolysis of waste lubricating oil and analyze its performance. The Peng-Robinson fluid package was used for the simulation. The pyrolysis reaction was modeled by a combination of the yield-shift reactor and the Gibbs reactor. At a pyrolysis temperature of 3500C and atmospheric pressure, 77.92% liquid yield was obtained. The product composition and chemical properties of the pyrolysis oil were also predicted by the simulation and are in good agreement with experimental results. This has proved that pyrolysis of Waste lubricating oil can give a very good yield of liquid product and is a viable recycling technique.
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    Ecotoxicology of glyphosate and recent advances in its mitigation by adsorption
    (Springer Berlin Heidelberg, 2021-01-01) Ighalo, Joshua O.; Ajala, Oluwaseun Jacob; Adeniyi, Adewale George; Babatunde, Esther O.; Ajala, Mary A.
    Glyphosate (N-[phosphonomethyl]glycine) is one of the most popular herbicides now used in agricultural practice. The aim of this paper was to discuss the research progress and innovations in recent years on the mitigation of glyphosate (GLY) from aqueous media by adsorption. The ecotoxicology of GLY was discussed in the domain of its chronic and sub-chronic toxicity, genotoxicity, reproductive toxicity, and carcinogenicity, and potential risks of food contamination were discussed. It was observed that polymers and resins are the best class of adsorbents for GLY adsorption from aqueous media. GLY adsorption was best fit to either Freundlich or Langmuir isotherm depending on the nature of the adsorbent. The pseudo-second-order kinetics was also the best fit for modelling the kinetics of GLY adsorption. A review of the thermodynamics revealed that GLY adsorption was usually spontaneous and exothermic. Research trends and knowledge gaps are in the area of chemical mobility in environmental systems (especially in the presence of other chemical species), the use of heavy metal-laden adsorbent and molecular modelling. Furthermore, it was observed that the ecotoxicology of GLY still has some contentious areas where there is no conclusive stance.
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    Modelling and simulation of banana (Musa spp.) waste pyrolysis for bio-oil production
    (Biofuels (Taylor & Francis), 2018-11-07) Adeniyi, A. G.; Ighalo, Joshua O.; Amosa, M. K.
    Banana (Musa Spp.) is a widely cultivated fruit in tropical West Africa and it generates a lot of waste due to its single fruit production per lifecycle and relatively large plant size. The recovery of energy from biomass is achievable through different thermochemical process among which pyrolysis is a key technique. In this study, ASPEN Plus v8.8 was used to develop a steady state simulation model for the predicting of pyrolysis product yields for different banana (Musa Spp.) wastes. The results obtained revealed bio-oil yields of 26.7%, 39.9% and 35% from the pseudo-stem, peel and leaves respectively. The pseudo-stem gave the highest char yield while gas yields were similar for all samples pyrolysed. The results showed that the peel will give more oil yield than the other banana wastes. Consequently, all banana (Musa Spp.) wastes has been shown to be inherently more suitable for char optimised production processes due to their compositional characteristics.
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    Modelling of integrated processes for the pyrolysis and steam reforming of rice husk (Oryza sativa)
    (Springer Nature Switzerland, 2019) Adeniyi, Adewale George; Ighalo, Joshua O.; Aderibigbe, Fatai Aderibigbe
    Thermochemical processes can be used to harness the energetic content of agricultural residues. This study utilises ASPEN Plus v8.8 to develop thermodynamic models for pyrolysis and in-line steam reforming of rice husk (Oryza sativa). The pyrolysis simulation at 500 °C and 1 atm gave a product yield of 36.3% oil, 49.6% char and 14.1% gas. Whilst the gas was composed of lighter hydrocarbons, the char was primarily elemental carbon and SiO2. The pyrolysis oil was composed of higher hydrocarbons, an assortment aromatic compounds and pyrolytic water. Optimum parameters for the steam reforming process were 700 °C, 1 atm and a steam-to-gas molar ratio of 7. The product composition at optimal conditions was 67% hydrogen gas, 19% carbon dioxide, 12% carbon monoxide and 2% methane. For a theoretical biomass feed of 200 kg/h and steam feed of 1400 kg/h, the synthesis gas flowrate obtained from the process was 204 kg/h and the rest were char and condensate water. This has gone a long way to reinforce our idea that the energy content of locally sourced rice (O. sativa) husk can be harnessed via different thermochemical techniques to give good yields of very useful products.
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    Process Integration and Feedstock Optimisation of a Two-Step Biodiesel Production Process from Jatropha Curcas Using Aspen Plus
    (Chemical Product and Process Modeling (De Gruyter), 2018-11-12) Adeniyi, A. G.; Ighalo, Joshua O.; ELETTA, O. A. A.
    Jatropha curcas oil (JCO) has been recognized as a viable non-edible feedstock for biodiesel production with the focus of achieving lesser reliance on fossil fuels. The aim of this work is to integrate and simulate the production of biodiesel from Jatropha curcas oil by a two-step process; a hydrolysis step and a trans-esterification step. The challenge is then to optimise the feedstock ratios to obtain the minimal water and methanol consumption to give optimal biodiesel yield. For this purpose, steady-state simulation model of a two-step production process of biodiesel from Jatropha curcas oil was prepared using ASPEN Plus V8.8. The response surface methodology (RSM) based on a central composite design (CCD) was used to design optimisation experiments for the research work. From the ANOVA, methanol/oil ratio of the trans-esterification step was found to have a significant effect on the biodiesel yield compared to the water/oil ratio of the hydrolysis step. The linear model developed was shown to be a good predictor of feedstock ratios for biodiesel yield. The surface plot revealed that both feedstock ratios do not show a significant combinatorial effect on each other. Numerical optimisation gave the optimum values of the feedstock ratios as a methanol/oil ratio of 2.667 and a water/oil ratio of 1. The optimisation results also indicated a predicted optimum biodiesel yield of 10.0938 kg/hr.
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    Study of Process Factor Effects and Interactions in Synthesis Gas Production via a Simulated Model for Glycerol Steam Reforming
    (Chemical Product and Process Modeling (De Gruyter), 2018-09-01) Adeniyi, A. G.; Ighalo, Joshua O.
    With the continual global focus in biodiesel production, a glut of glycerol (it’s by-product) is expected in the world market. One viable and proven possibility in utilising the less useful and desired glycerol as a source for the production of hydrogen via the steam reforming and water gas shift process. This study is essentially and in-depth investigation of the interaction of the key process factors and their effect on the selectivity of Hydrogen from the process. The basis of the investigation was a simulated model of the steam reforming process using ASPEN plus V8.8. Results were obtained according to the optimisation plan developed using central composite design (CCD). The variables (and range) were temperature (700 0c – 1100 0c), Pressure (0.1 atm – 1.9 atm) and steam to glycerol ratio (1 mol/mol – 12 mol/mol). The results of optimisation showed that maximum yield of H2 and minimal methanation can be obtained at a temperature of 900 0c, an STGR of 15.75 mol/mol and at atmospheric pressure. The optimum result was predicted by the simulation as H2 = 66.72 %, CO = 11.76 %, CO2 = 21.52 % and CH4 = 0 %. Sensitivity analysis was carried out to show that Hydrogen production is favoured at higher temperatures and methanation at lower temperatures respectively. A critical investigation of the factor effects and interactions for each product in the synthesis gas (dry basis) was also carried out using response surface methodology.