4 research outputs found
Investigation of the Effects of Torrefaction Temperature and Residence Time on the Fuel Quality of Corncobs in a Fixed-Bed Reactor
Biomass from agriculture is a promising alternative fuel due to its carbon-neutral feature. However, raw biomass does not have properties required for its direct utilization for energy generation. Torrefaction is considered as a pretreatment method to improve the properties of biomass for energy applications. This study was aimed at investigating the effects of torrefaction temperature and residence time on some physical and chemical properties of torrefied corncobs. Therefore, a fixed-bed torrefaction reactor was developed and used in the torrefaction of corncobs. The torrefaction process parameters investigated were the torrefaction temperature (200, 240, and 280 °C) and the residence time (30, 60, and 90 min). The effects of these parameters on the mass loss, grindability, chemical composition, and calorific value of biomass were investigated. It was shown that the mass loss increased with increasing torrefaction temperature and residence time. The grinding throughput of the biomass was improved by increasing both the torrefaction temperature and the residence time. Torrefaction at higher temperatures and longer residence times had greater effects on the reduction in particle size of the milled corncobs. The calorific value was highest at a torrefaction temperature of 280 °C and a residence time of 90 min. The energy yield for all treatments ranged between 92.8 and 99.2%. The results obtained in this study could be useful in the operation and design of torrefaction reactors. They also provided insight into parameters to be investigated for optimization of the torrefaction reactor
Investigation of the Effects of Torrefaction Temperature and Residence Time on the Fuel Quality of Corncobs in a Fixed-Bed Reactor
Biomass from agriculture is a promising alternative fuel due to its carbon-neutral feature. However, raw biomass does not have properties required for its direct utilization for energy generation. Torrefaction is considered as a pretreatment method to improve the properties of biomass for energy applications. This study was aimed at investigating the effects of torrefaction temperature and residence time on some physical and chemical properties of torrefied corncobs. Therefore, a fixed-bed torrefaction reactor was developed and used in the torrefaction of corncobs. The torrefaction process parameters investigated were the torrefaction temperature (200, 240, and 280 °C) and the residence time (30, 60, and 90 min). The effects of these parameters on the mass loss, grindability, chemical composition, and calorific value of biomass were investigated. It was shown that the mass loss increased with increasing torrefaction temperature and residence time. The grinding throughput of the biomass was improved by increasing both the torrefaction temperature and the residence time. Torrefaction at higher temperatures and longer residence times had greater effects on the reduction in particle size of the milled corncobs. The calorific value was highest at a torrefaction temperature of 280 °C and a residence time of 90 min. The energy yield for all treatments ranged between 92.8 and 99.2%. The results obtained in this study could be useful in the operation and design of torrefaction reactors. They also provided insight into parameters to be investigated for optimization of the torrefaction reactor
Sero-Epidemiology of Transfusion Transmissible Hepatitis B, C and E among Blood Donors in Ekiti, Southwestern Nigeria: A Cross-sectional Study
Background: Transfusion transmissible hepatitis (TTH) is a global health problem and the incriminating agents such as hepatitis B virus (HBV), hepatitis C virus (HCV) and hepatitis E virus (HEV) continue to pose serious threats to blood safety. The aim of this study was to determine the seroprevalence of HBV, HCV and HEV and relate the outcomes with blood donation type, age and gender and confirm any significant associations. Materials and Methods: In this cross-sectional study, Hepatitis B surface antigen (HBsAg) and antibody to HCV were determined with Diaspot and Lab Acon immunochromatographic ELISAbased test devices. Antibodies to HEV were first determined with Biopanda lateral flow device followed by ELISA assay for sero-reactive HEV immunoglobulins M and immunoglobulin G (IgM and IgG) antibodies. Results: A total of 370 prospective blood donors between 18 and 55 years old (mean 31.2 ± 7.6 years) who presented for blood donation at FETHI Blood Bank were screened. Overall male: female ratio was 7:1. Cummulative hepatitis seroprevalence of 8.1% was found mainly among the replacement blood donors (RBD) and consist of 4.3%, 1.6%, 1.1%, 0.8% and 0.3% serologic evidence of HBsAg, anti-HCV, HEV IgM, both HEV IgM & HEV IgG, and HEV IgG antibodies. Blood donors aged 18 – 45 years were most affected with evident significant association between the age group of donors and TTH seroprevalence. Cummulative hepatitis seroprevalence was 0% among voluntary blood donors, and 9.1% and 0.3% among the male and female RBD respectively. There was significant association between the pathogens and RBD, though the association with male gender was clinically but not statistically significant. Conclusion: The high transfusion transmissible hepatitis seroprevalence among RBD called for promoting voluntary donations. Comparable prevalence of HEV antibodies with that of HCV called for its inclusion in the TTIs screening algorithm to ascertain optimal blood safety in Nigeria