Browsing by Author "Olorunnisola A.O."

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A review on the renewable energy from agricultural and forest residues in nigeria
(2021) Olorunnisola A.O.; Richards,A.; Omoniyi T.E.
Nigeria is blessed with abundant natural resources among them are residues from agricultural and forest sources. Since these residues are usually dumped in landfills as waste, constituting environmental and waste disposal problems, the need to utilise them is necessary in achieving the seventh and ninth targets of the Sustainable Development Goals (SDGs) of the United Nations. One of the avenues where agricultural and forest residues can be utilised is through biomass technology. Therefore, this paper assessed the potential conversion of these residues into useful and sustainable electricity generation in Nigeria. In addition, the paper gathers information from a pool of relevant reports on the current state of Nigeria’s power sector and the domestication of some small-scale biomass power plants across the country. In this review paper, it was found that Nigeria is one of the biggest economic power in Africa and has the potential to generate electricity and other bioenergy products from the present stock of biomass available in the country, thereby making the country self-sufficient in the provision of power supply and fuel production.
Combustion characteristics of briquettes produced from three binders and torrefied gmelina arborea (robx.) sawdust
(2023) Bello R.S.; Olorunnisola A.O.; Omoniyi T.E.; Onilude M.A.
Considering the energy potential of briquettes, there are several undesired harmful qualities such as intense yellow flame and smoke. Torrefaction was deemed a suitable technological solution, therefore, the study investigated the combustion properties of briquettes made from Gmelina arborea sawdust and three binders used print paper (UPP), newsprint (Np) and clay (CL). Materials and Methods: Experiments were conducted using a hydraulic press and a biomass stove. The 3 torrefied feedstock samples (TS 30, TS 45 and TS 60 min) were mixed with binders at 10, 20, 30, 40 and 50% w/w at 1.67 kPa applied pressure and 5 min residence period to produce briquettes. The results were statistically analyzed at significance level using ANOVA. Results: Briquette densities decreased with an increase in torrefaction time with strong positive correlations between densities of the same binder type, concentration and torrefaction time. An increase in binder concentration enhanced the combustion characteristics of UPP and Np briquettes positively, with significant negative effects on CL briquettes. Torrefied used printing paper briquette burns with non-luminous flame and reduced smokiness as binder concentration increases, while newsprints briquette produced excessive smokes. Briquettes produced from used printing papers at 45 min torrefaction had better performances in terms of energy values, product flammability and reduced smokiness. Clay-bonded briquettes had delayed ignition 7-10 min and failed to burn with flame, rather than by char combustion. Conclusion: Torrefaction time, binder type and concentration had significant positive effects on the combustion characteristics. Clay had poor effects on combustion characteristics.
Development of a multiple-piston hydraulic briquetting press hbp and characterization of newsprint briquettes produced
(2023) Bello R.S; Olorunnisola A.O.; Omoniyi T.E.; Onilude M.A.
Technical complexity, power source, cost, and product value are some challenging considerations in briquetting. Most of the available briquetting options are not sustainable due to these challenges, therefore, improved intermediate technology options requiring low energy consumption, high-energy product and acceptable combustion characteristics to meet these challenges are justified by developing a multiple-piston hydraulic briquetting press (HBP) and characterizing the briquettes produced from Gmelina arborea sawdust and newsprint binder. Materials and Methods: Sorted Gmelina arborea sawdust was mixed with pulped newsprint fibers in 5 ratios 10, 20, 30, 40 and 50%, respectively, to produce briquettes. The briquettes were characterized using American Society for Testing and Materials (ASTM), British Standard (BS), and International Standards Organization (ISO) test procedures to determine briquette characteristics. Results: The machine output capacity was 96 briquettes/hour, with low production cost (NGN40, 000.00). The briquettes produced are structurally stable with dimensions: 15.00 mm internal hole, 80.00 mm external diameter, and 60.00 mm height. Low binder briquettes (90:10% wt/wt) are fragile and brittle, while higher binder briquettes are strong and durable. Binder concentration positively improves the combustion characteristics, while the time spent cooking 1 kg of yam is not significantly different for rice. The briquettes thermal efficiency in stove was significantly affected by binder concentration and stove characteristics. Conclusion: The outcomes of this study including high machine output capacity, briquettes’ stability, luminous flame and reduced smokiness showed positive quality contributions to densification study and hence, suitability for domestic heating.
Effect of residence time on characteristics of torrefied sawdust produced from gmelina arborea (roxb) wood
(2022) Bello R.S.; Olorunnisola A.O.; Omoniyi T.E.
Biomass feedstock remains a critical ingredient in all densification studies and the process conditions under which these materials were produced are significant to its performance. Conventionally, feedstocks are utilized in briquetting without major technological processing which is consequential on product characteristics. In this study, sawdust of Gmelina arborea subjected to thermochemical pre-treatment conditions was analysed and characteristics were compared with untreated material. Materials and Methods: Untreated sawdust of Gmelina arborea wood obtained from a sawmill in Ishiagu was torrefied at three residence times of 30 min, 45 and 60 min at a temperature of 250EC in a batch reactor and the products were characterized to determine their physical and chemical characteristics. Results: The particle-size distribution of untreated sawdust showed greater proportions of coarse and fine pin particles (58.03%) and (38.00%), respectively, requiring no grind with a mean particle density of 159.30±0.02. The proximate analysis of untreated sawdust at 7.78% moisture content revealed a volatile matter content of 72.93, 2.19% ash content and 17.10% carbon content. The proximate analysis of torrefied samples revealed a significant loss in volatile matter contents to 21.02% as residence time increased to 60 min, the fixed carbon increased from 17.10-65.38% and calorific values from 17.38 MJ kgG1 for raw sawdust to 26.28 MJ kgG1 as residence time increases. Reduction in volatile matter contents increased the energy values of torrefied sawdust. Conclusion: Thermochemical pretreatment of the feedstock significantly increase the material fixed carbon content and energy values of the Torrefied sample, reduced the volatile matter-the smoke-generating component of sawdust considerably and improved the product’s characteristics in briquetting.
Effects of binder concentrations and soaking time on combustion characteristics of briquettes produced from fermented gmelina arborea (roxb) sawdust and used print paper
(Black Sea Agricultural Research Institute (KTAE) Samsun, Türkiye, 2022) Bello R.S.; Olorunnisola A.O.; Omoniyi T.E.; Onilude M.A.
Low-density briquettes are known for having several undesirable characteristics, such as an intense yellow flame and smokiness that are too high for domestic applications. The pretreatment of feedstock has been identified as a tool for addressing these issues; however, process costs and variability conditions has significant impact on the selection and performance of these methods. Consequent on these, fermentation method was employed to investigate the effects of binder concentration and soaking time on briquettes produced from fermented G. arborea sawdust and used print paper binder in this work. Untreated sawdust samples were collected from sawmill's dumpsite and soaked for 12, 24, 36, and 48 hours under mesophilic and anaerobic conditions while used print paper were converted into pulped fiber. Briquette mix ratio by percentage weight proportions varied from (10:90-50:50) % dry basis. A statistical analysis of briquette densities revealed a significant positive correlation between the densities of fermented briquettes and the binder concentration at (p<0.05). Thermal efficiency decreased with increase in binder concentration with no significant difference in fermentation time, while the specific fuel consumption increased with increase in binder concentration. Fermentation time and binder concentration slightly improved the combustion characteristics of briquettes. Economic analysis suggested economic viability of the process.
Performance of briquettes produced from sawdust of gmelina arborea and montmorillonite clay as binder
(Black Sea Agricultural Research Institute (KTAE) Samsun, Türkiye, 2023) Bello R.S.; Olorunnisola A.O.; Omoniyi T.E.; Onilude M.A.
Clay had been used as binders in briquetting research activities, however their performance characterization in terms of quality and combustion have not been clearly evaluated or reported. This study therefore provide a qualitative evaluation of briquettes produced using sawdust of Gmelina arborea and montmorillonite clay. Sun-dried sawdust (~9% moisture contents) obtained from sawmills in Ishiagu, Ebonyi State were mixed with processed clay samples collected from earthen pot mould sites characterized, then used in briquette production using five mixing ratios of 90:10, 80:20, 70:30, 60:40, & 50:50 (weight/weight)% and standard test procedures for characterization. Data were analyzed using SPSS at p< 0.05 significance levels. The quality characteristics of clay briquettes compared favourably with other binder types with an increase in performance as binder concentration increases. The briquettes combustion performance in air and stove are significantly affected by the agglomerated non-combustible clay particle impregnating the biomass matrix. Best combustion performance occurred at 10% binder concentration with no significant value-addition to ignition time, flame combustion and heating values. Above 10% binder addition, briquettes failed self-ignition, flame combustion, and retarded char combustion tests. This implied clay is a poor performing binder and the associated briquette are combustibly poor.
Sorption characteristics of cement composite reinforced with some locally available lignocellulosic materials in Nigeria
(2013) Omoniyi T. E.; Olorunnisola A.O.; Akinyemi B.A.
The aim of this study was to investigate the sorption property of wood cement composite produced from bagasse (Saccharum officinarum), bamboo (Bambusa vulgaris) and coir (Cocos nucifera L). The mass of the fibre varies from 1 to 6% of the mass of cement. The result indicated that the mass fraction has significant effect on the sorption properties of the composites. Water absorption (W.A.) rate increases with increase in the fibre content of the composites. Thickness swelling (T.S.) in all the composites was less than 1.7% at 24 h water immersion at room temperature. There was linear correlation between mass fraction, water absorption and thickness swelling of the composites. The relatively low W.A. capacity and T.S. at content less than 3% of mass of cement suggests that they can be employed in outdoor situations and at this level they are dimensionally stable but beyond this level it is not advisable.