Unizik Journal of Technology, Production and Mechanical Systems

Optimum proportion of starch binder and palm kernel shell hybrid additive in the formation of sawdust based composite briquette

Seun Oyelami — 2024-01-25

Briquette making involves collection of combustible materials not useable because of their low density and compressing them into solid fuel of convenient shape. Briquette has lower ash content, high heat and calorific value than most fuels. Thus, this study investigated 200g of pure sawdust and five other briquettes of percentage by mass ratios of sawdust to palm kernel shell of 90:10, 80:20, 70:30, 60:40, and 50:50, were made dry and without binder. The briquettes were tested for crushing strength and calorific value. The best of the briquettes which is 70:30 percentages was picked and its composition was used to make another set of five briquettes but with starch of masses 10g, 20g, 30g, 40g and 50g respectively. The briquettes with starch content were tested for calorific value only. Consequently, the data obtained from the results showed that addition of palm kernel shell increases the calorific value from 15,668KJ/kg when there was no palm kernel shell addition to 18,397kJ/kg at palm kernel shell addition up to 30% beyond which the calorific value decreases. However, addition of starch binder to the briquette raised the calorific value to 20,377kJ/kg when the starch addition was up to 4.8% beyond which the calorific value decreases. Result shows that 4.8% of starch addition was insufficient for the composite briquette. However, 13% of starch binder briquette a calorific value of 20,005kJ/kg is considered the best. 13% of starch binder briquette could be developed for usage in boiler, heating purpose and gasification plants to replace conventional fuel sources.

Comparative Analysis: Heat flow & drying performance in a dual Electric/gas convective dryer

Okeke John Chikaelo — 2024-01-25

This study scrutinizes convective dryers at 45°C and 60°C, comparing the impact of electric and gas heat sources on heat flow and drying performance. By analyzing temperature changes within dryer compartments, we uncovered unique behaviors for each heat source. Gas showed faster moisture reduction compared to electric, achieving 9.81%wb and 9.39%wb at 45°C and 60°C in 33 and 21 hours, respectively, compared to 10.08%wb and 10.22%wb in 34 and 22 hours for electric. Effective diffusivity increased from 8.792 ×10^-8 m²/s to 1.22 ×10^-7 m²/s for electric and 8.9×10^-8 m²/s to 1.42×10^-7 m²/s for gas. Activation energy was 39.08kj/mol for electric and 42.59kj/mol for gas. The Page model demonstrated high accuracy (R² = 0.9968, RMSE = 0.0132, X² = 0.0002) across temperatures and heat sources for drying Clarias gariepinus. The findings suggest practical implications for industrial drying processes, highlighting the potential advantages of gas-based drying systems for faster and more efficient drying operations. Further exploration of these findings could lead to optimized drying methodologies, potentially enhancing efficiency in various drying applications within the industry.

Effects of nanoparticles volume fractions on the viscosity of nanofluids prepared from palm kernel shell nanoparticles

Okafor A. A — 2024-04-16

In this research, palm kernel shell nanoparticles were produced for nanofluid application and the viscosity of the produced nanofluids was measured. The size of the nanoparticles fabricated is 100nm diameter. This paper presents results on the synthesis of palm kernel shell bio-material to obtain nanoparticles and subsequently produced nanofluids. Nanofluids were prepared using two-step method by dispersing or pouring palm kernel shell- nanoparticles into the base fluid (a binary mixture of Ethylene Glycol (EG) and deionised water (base fluid) in a ratio of 50:50) .An ultrasonic sonicator was used to ensure proper mixtures of different volume fractions (0.3%, 0.6 %, 0.9 % 1.2 % and 1.5%) of palm kernel shell nanoparticles into base fluid (a binary mixture of Ethylene Glycol (EG) and deionised water). A Vibro Viscometer machine (SV-10) was used to measure the viscosity of the prepared nanofluids more easily. For minimum and maximum volume fractions of palm kernel shell nanoparticles (0.3% and 1.5%) in the base fluid, the viscosity was found to be 26 mPa.s and 43 mPa.s, which increases slightly with an increase of particle volume fraction and decreases as the temperature increases. The experimental results show a maximum of 23% increasing of viscosity for 1.5% volume fraction of nanofluids as compared with the base fluid. From the experimental study on prepared nanofluids conducted, results show that all the values of viscosities at different volume fractions of the prepared nanofluids were found to be higher than the values of the base fluids (a binary mixture of Ethylene Glycol (EG) and deionised water). The experiments were conducted at varying temperature range (300C through 700C).