Main Article Content

Abstract

In this study, the drying kinetics of maize dried in a biomass-powered inclined bed dryer were studied using ten (10) thin-layer mathematical drying models. The drying system recorded an average plenum temperature of 73.54 oC during the drying experiment compared to an average ambient temperature of 28.41 oC. Maize grains with an initial average moisture content of 23.25 % on a wet basis were reduced to 13.61 % average final moisture content over a drying period of 2 hours 40 minutes. The results revealed a moisture extraction rate, drying rate, and drying efficiency of 6.70 kg/h, 9.50 kg/h, and 71.37 %, respectively. The two-term model best describes the thin-layer drying kinetics of maize in the biomass-powered inclined bed dryer based on the coefficient of determination (R2) and root mean square error (RMSE) values of 0.998 and 0.00738, respectively. The two-term model showed a better fit between the experimental and the predicted moisture ratios. The drying process occurred in the falling rate period with an effective moisture diffusivity of 4.65x10-9 m2/s and activation energy of 21.31 kJ/mol. The two-term model was able to imitate the behaviour of the drying process of maize in the drying system. The model would assist in predicting the drying time for different moisture contents of maize in the scale-up of the drying system and, accordingly, help farmers and agro-processors in planning drying schedules. The drying kinetics of other staples like cassava and rice are recommended for further studies using the biomass-powered inclined bed dryer. 

Keywords

Thin-layer Drying Kinetic Modelling Effective Moisture Diffusivity Activation Energy

Article Details

Author Biographies

Joseph Oppong Akowuah, Department of Agricultural and Biosystems Engineering, Kwame Nkrumah University of Science and Technology, Kumasi, Ghana

Senior Lecturer at Agricultural and Biosystems Engineering Department/KNUST

 

 

George Obeng-Akrofi, Department of Agricultural and Biosystems Engineering, Iowa State University, Ames, Iowa USA

 

 

Edward Awafo, Department of Agricultural and Bioresources Engineering, University of Energy and Natural Resources, Sunyani, Ghana

Senior lecturer. Department of Agricultural and Bioresources Engineering, University of Energy and Natural Resources.

 

References

  1. Afriyie, J. K., Rajakaruna, H., Nazha, M. A., and Forson, F. K. (2013). Mathematical modelling and validation of the drying process in a Chimney-Dependent Solar Crop Dryer. Energy Conversion and Management, 67, pp. 103-116. https://doi.org/10.1016/j.enconman.2012.11.007
  2. Aghbashlo, M., and Samimi-Akhijahani, H. (2008). Influence of drying conditions on the effective moisture diffusivity, energy of activation and energy consumption during the thin-layer drying of berberis fruit (Berberidaceae). Energy Conversion and Management, 49(10), pp. 2865-2871. https://doi.org/10.1016/j.enconman.2008.03.009
  3. Akowuah, J. O., Bart-Plange, A., and Dzisi, K. A. (2021). Thin layer mathematical modelling of white maize in a mobile solar-biomass hybrid dryer. Research in Agricultural Engineering, 67(2), pp. 74-83. https://doi.org/10.17221/56/2020-RAE.
  4. Akowuah, J. O., Mensah, L. D., Chian, C., and Anthony, R. (2015). Effects of practices of maize farmers and traders in Ghana on contamination of maize by aflatoxins: Case study of Ejura-Sekyeredumase Municipality. African Journal of Microbiology Research, 9(25), pp. 1658-1666. https://doi.org/10.5897/AJMR2014.7293
  5. Akowuah, J., Maier, D., Opit, G., McNeill, S., Amstrong, P., Campabadal, C., Ambrose, K. and Obeng-Akrofi, G. (2018). Drying Temperature Effect on Kernel Damage and Viability of Maize Dried in a Solar Biomass Hybrid Dryer. Open Journal of Applied Sciences, 8, pp. 506-517. https://doi.org/10.4236/ojapps.2018.811041
  6. Alhassan, N. F., and Kumah, P. (2018). Determination of postharvest losses in maize production in the upper West region of Ghana. American Scientific Research Journal for Engineering, Technology, and Sciences, 44(1), pp. 1-18.
  7. Anuar, M. S., Taip, F. S., Shamsudin, R., and AM, S. R. (2017). Effective moisture diffusivity and activation energy of rambutan seed under different drying methods to promote storage stability. In IOP Conference Series: Materials Science and Engineering, 203 (1), pp. 25. https://doi.org/10.1088/1757-899X/203/1/012025
  8. Da Silva, W. P., e Silva, C. M., Gama, F. J., and Gomes, J. P. (2014). Mathematical models to describe thin-layer drying and to determine drying rate of whole bananas. Journal of the Saudi Society of Agricultural Sciences, 13(1), pp. 67-74. https://doi.org/10.1016/j.jssas.2013.01.003
  9. Darfour, B., and Rosentrater, K. A. (2016). Maize in Ghana: an overview of cultivation to processing. In 2016 ASABE Annual International Meeting. American Society of Agricultural and Biological Engineers, pp. 1. https://doi.org/10.13031/aim.20162460492
  10. Doymaz, I. (2008). Convective drying kinetics of strawberry. Chemical Engineering and Processing: Process Intensification, 47(5), pp. 914-919. https://doi.org/10.1016/j.cep.2007.02.003
  11. Doymaz, I., and Pala, M. (2003). The thin-layer drying characteristics of corn. Journal of food engineering, 60(2), pp. 125-130. https://doi.org/10.1016/S0260-8774(03)00025-6
  12. Ghana Statistical Service. (GSS). (2014). District Analytical Report, Kumasi Metropolitan Assembly (PDF). Accra Ghana: Ghana Statistical Service. [ONLINE]. Available at: https://www.statsghana.gov.gh/docfiles/2010_District_Report/Ashanti/KMA.pdf [Accessed 12 September 2021]
  13. Henderson, S. M. (1974). Progress in developing the thin layer drying equation. Transactions of the ASAE, 17(6), pp. 1167-1168.
  14. Hussein, J. B., Filli, K. B., and Oke, M. O. (2016). Thin layer modelling of hybrid, solar and open sun drying of tomato slices. Research Journal of Food Science and Nutrition, 1(1), pp. 15-27. https://doi.org/10.1088/1757-899X/203/1/012025
  15. Inyang, U. E., Oboh, I. O., and Etuk, B. R. (2018). Kinetic models for drying techniques—food materials. Advances in Chemical Engineering and Science, 8(2), pp. 27. https://doi.org/10.4236/aces.2018.82003
  16. Kaaya, A. N., and Kyamuhangire, W. (2010). Drying maize using biomass-heated natural convection dryer improves grain quality during storage. Journal of Applied Sciences, 11, pp. 967-974. https://doi.org/10.3923/jas.2010.967.974
  17. Ministry of Food and Agriculture (MoFA). (2020). Agriculture in Ghana: Facts and Figures. Statistics, Research and Information Directorate (SRID). Available at: https://srid.mofa.gov.gh/sites/default/files/Agriculture%20In%20Ghana%20Facts%20%26%20Figures_%202020%20FINAL.pdf [Accessed 5 February 2022].
  18. Mujumdar, A. S. (2006). Handbook of industrial drying. CRC press.
  19. Obeng-Akrofi, G., Akowuah, J. O., Maier, D. E., and Addo, A. (2021). Techno-economic analysis of a crossflow column dryer for maize drying in Ghana. Agriculture, 11(6), pp. 568. https://doi.org/10.3390/agriculture11060568
  20. Page, G. E. (1949). Factors Influencing the Maximum Rates of Air-Drying Shelled Corn in Thin layers. Purdue University.
  21. Sharaf-Eldeen, Y., Blaisdell, J. and Hamdy, M. (1980). A Model for Ear Corn Drying. Transactions of the ASAE. 23, pp. 1261-1265. https://doi.org/10.13031/2013.34757
  22. Tweneboah, C. K. (2000). Modern agriculture in the tropics with special reference to Ghana. Co-Wood Publishers, Accra, pp. 37-40.
  23. Vega-Gálvez, A., Miranda, M., Díaz, L. P., Lopez, L., Rodriguez, K., and Di Scala, K. (2010). Effective moisture diffusivity determination and mathematical modelling of the drying curves of the olive-waste cake. Bioresource Technology, 101(19), pp. 7265-7270. https://doi.org/10.1016/j.biortech.2010.04.040
  24. Wang, C. Y., and Singh, R. P. (1978). A single layer drying equation for rough rice. ASAE paper. Available at: http://www.sciepub.com/reference/161016 [Accessed 5 March 2022].
  25. Wang, W., Li, M., Hassanien, R. H. E., Wang, Y., and Yang, L. (2018). Thermal performance of indirect forced convection solar dryer and kinetics analysis of mango. Applied Thermal Engineering, 134, pp. 310-321. https://doi.org/10.1016/j.applthermaleng.2018.01.115
  26. White, G. M., Bridges, T. C., Loewer, O. J., and Ross, I. J. (1980). Seed coat damage in thin-layer drying of soybeans. Transactions of the ASAE, 23(1), pp. 224-0227. https://doi.org/10.13031/2013.34559
  27. Yagcioglu, A. D. A. C. F. (1999). Drying characteristic of laurel leaves under different conditions. In Proceedings of the 7th international congress on agricultural mechanization and energy, Faculty of Agriculture, Cukurova University, pp. 565-569.
  28. Zhang, Q., and Litchfield, J. B. (1991). An optimization of intermittent corn drying in a laboratory scale thin layer dryer. Drying technology, 9(2), pp. 383-395. https://doi.org/10.1080/07373939108916672