Papers by Mogomotsi Molefe
Drying is an energy consuming process influenced by humidity, air velocity and temperature and is... more Drying is an energy consuming process influenced by humidity, air velocity and temperature and is defined as a heat conveyance process wherein the product is heated hence removing moisture. Thin layer drying equations are used to estimate drying times of products and generalizing their drying curves. In this study, mathematical modelling and prediction of drying behavior of poultry litter briquettes (PLB) was investigated through open sun drying (OSD) and solar tunnel drying for moisture content (MC) calculations. A solar tunnel dryer (STD) having a: black painted collector unit, drying unit and black painted vertical bare flat-plate chimney was used. MC results were converted to moisture ratio and fitted into 12 different thin layer drying models, using Microsoft Office Excel, which were compared according to their coefficients of determination to estimate drying curves of PLB. The most accurate model was selected based on three statistical parameters: correlation coefficient (R 2), chi-squared (χ 2) and Root Mean Square Error (RMSE). Solar insolation of between 220 and 1005 W/m 2 resulted in air temperature of up to 64 o C at the collector unit, up to 60 o C at the drying unit and an ambient temperature of up to 31 o C. Exposure of PLB with an average initial MC of 61% (w.b.) to these conditions resulted in a final MC in a range of 0.2-11.2% (w.b.) in 31-55 hours. PLB was dried to similar final weight from whichever drying method although OSD took longer than STD. The Logarithmic model was found to satisfactorily describe the drying curves of PLB with R 2 of 9.93E-01-9.99E-01; χ 2 of 1.36E-11-6.50E-14; and RMSE of 2.94E-02-1.30E-02.
Confined poultry production, which is expected to double by 2050, produces a lot of litter. For s... more Confined poultry production, which is expected to double by 2050, produces a lot of litter. For successful and sustainable poultry production, litter management is prompted and should be prioritized. Poultry litter can serve as an energy feedstock for space heating and electricity generation. Currently, heating systems in use depend on electricity, charcoal or diesel which are very expensive leading to high energy costs in poultry production. The purpose of this study was therefore to investigate the potential of combustion of poultry litter for space heating in poultry production. A brazier with 32 holes, of a diameter of 1cm, on its sides comprising of dimensions; Diameter=8 cm and Height=65 cm was used to burn 1kg of Poultry Litter Briquettes. The briquettes were made with a mincer which had a nozzle of dimensions, Length=11 cm and Diameter= 25 mm producing briquettes of a diameter of 25 mm and a length of 10 cm. The briquettes were made from poultry litter of chickens at the ages of 4, 5 and 6 weeks, and were either sun or solar dried. They were then directly combusted in the brazier and heat distribution was measured at distances of 30 cm, 60 cm and 90 cm from the brazier. Charcoal was used as a control. The maximum average temperatures recorded on the surface of the brazier for week 4, 5, 6 were 471 o C, 491 o C, 493 o C respectively; whereas for charcoal was 555 o C. However, the poultry litter briquettes were not able to sustain high temperatures for long compared to charcoal. Complete combustion took an average of 120 minutes while charcoal took an average of 180 minutes.
Energy and Environment Research
Confined poultry production, which is expected to double by 2050, produces a lot of litter. For s... more Confined poultry production, which is expected to double by 2050, produces a lot of litter. For successful and sustainable poultry production, litter management is prompted and should be prioritized. Poultry litter can serve as an energy feedstock for space heating and electricity generation. Currently, heating systems in use depend on electricity, charcoal or diesel which are very expensive leading to high energy costs in poultry production. The purpose of this study was therefore to investigate the potential of combustion of poultry litter for space heating in poultry production. A brazier with 32 holes, of a diameter of 1cm, on its sides comprising of dimensions; Diameter=8 cm and Height=65 cm was used to burn 1kg of Poultry Litter Briquettes. The briquettes were made with a mincer which had a nozzle of dimensions, Length=11 cm and Diameter= 25 mm producing briquettes of a diameter of 25 mm and a length of 10 cm. The briquettes were made from poultry litter of chickens at the age...
Energy and Environment Research
Drying is an energy consuming process influenced by humidity, air velocity and temperature and is... more Drying is an energy consuming process influenced by humidity, air velocity and temperature and is defined as a heat conveyance process wherein the product is heated hence removing moisture. Thin layer drying equations are used to estimate drying times of products and generalizing their drying curves. In this study, mathematical modelling and prediction of drying behavior of poultry litter briquettes (PLB) was investigated through open sun drying (OSD) and solar tunnel drying for moisture content (MC) calculations. A solar tunnel dryer (STD) having a: black painted collector unit, drying unit and black painted vertical bare flat-plate chimney was used. MC results were converted to moisture ratio and fitted into 12 different thin layer drying models, using Microsoft Office Excel, which were compared according to their coefficients of determination to estimate drying curves of PLB. The most accurate model was selected based on three statistical parameters: correlation coefficient (R2),...
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Papers by Mogomotsi Molefe