Optimization of Process Variables of a Newly Developed Vertical Palm Fruit Digester as it Affects the Weight of Digested and Undigested Fruits

This work has conducted a study on the ‘Optimization of Process Variables of a Newly Developed Vertical Palm Fruit Digester as it affects the Weight of Digested and Undigested Fruits’. The optimization analysis of the palm fruit digester utilized three factors (speed, initial palm fruit weight, and number of blades) and the targeted responses were digested and undigested weight of palm fruits. The results obtained from the work showed that, the weight of digested fruit (Wd) response surface analysis showed that the model had a high significance (F = 86.63, p < 0.0001), thus indicating high predictive ability and a good fit. The weight of palm fruit at the start of the growth period (B) showed the strongest influence with a coefficient of 2.51 and very significant p-value (< 0.0001), hence, it proved to be the decisive influence of Wd. The weight of undigested fruit (Wu) response analysis revealed that the model lacked statistical significance on average (F = 3.05, p = 0.0888) and thus this response exhibits less predictive power relative to others. But among the factors used, the factor weight of palm fruit (Wi) turned out to be the main determinant, with a coefficient estimate of 0.49 and a very significant effect (p = 0.001). The work showed that the quadratic model of the weight of digested palm fruit is highly significant (F=86.63, p<0.0001) and that the vertical palm fruit digester can be accurately predicted with Response Surface Methodology (RSM). The weight of undigested fruit (Wu) ANOVA, proved that the general model was not significant (F = 3.05, p = 0.0888). The data showed a low predictive power in comparison with other responses. It is evident in the plot that the initial weight of palm fruit (Wi) has the most significant effect, which agrees with the result of the ANOVA, that only the wi (initial weight of palm fruit) had any significant effect (p < 0.0001). The ANOVA results are validated by the visualization, indicating that the initial weight of palm fruit (Wi) is the most significant variable. When Wi is raised, the quantity of undigested residue will correspondingly increase with contour gradients illustrating the positive linear association and finally based on Response Surface Methodology (RSM), the desirability plot describes the optimum operating point of the vertical palm fruit digester to achieve maximum efficiency (ŋ), digesting capacity (Dc) and minimum weight of undigested fruit (Wu), with weight of digested fruit (Wd) generated being a balanced output. The best settings: speed (A) of 595.873 RPM, starting weight B (Wi) of 5.472 kg and 6 blades (C)- resulting in Wd = 4.866 kg, Wu = 0.605 kg, Tn =1.095 min, Dc = 289.300 kg/h, n = 90.200 percent and viscosity = 0.048 Pa.s with a desirability of 1.000.

Optimization; Digested weight; Palm fruit; Undigested weight; Initial weight; Vertical palm fruit digester.

1. Agbonkhese, K., A., Frank, O., and Okojie, G. (2018). International Journal of Current Advanced Research ISSN: O: 2319-6475, ISSN: P: 2319-6505, Available Online at www.journalijcar.org Vol. 7; Page No. 9086-9092 [Google Scholar] [Crossref]

2. Allen S. H., Alfred R. H., and Herman G. L., (2002) “A Textbook on the Theory and Problems of Machine Design”; Tata McGraw-Hill Publishing Company Ltd: New Delhi. pp. 113-125, pp. 205-254, pp.290-297. [Google Scholar] [Crossref]

3. Amiolemhen, P. E., and Eseigbe, J. A. 2019. Design and Fabrication of a Palm kernel oil expeller machine. International Journal of Engineering Trends and Technology, vol 67, Issue 6. Pp. 39-46 2010 [Google Scholar] [Crossref]

4. Aniekan, A. (2025) Design, Production, and Optimization of Process Variables of a Vertical Palm Fruit Digester, M.Eng. Dissertation in the Department of Mechanical and Aerospace Engineering, Faculty of Engineering, University of Uyo, Uyo, Nigeria. [Google Scholar] [Crossref]

5. Anita, O. O; Olosunde, W., and Offiong A. (2014). Determination of optimum moisture L content of palm nut cracking for efficient production of whole kernel. Nigerian Journal of Technological Development, vol. 11, No. 2, pp. 27-30. [Google Scholar] [Crossref]

6. Asha, S. O., Ogenekaro, O, P., Obasha, I O., Emmanuel, S. O. and Ayewa, O. A. (2017). Development of a continues palm nuts digesting machine; science arena publications specialty. Journal of Engineering and Applied Science available online at www.sciateng.com vol. 3(4):1-19. [Google Scholar] [Crossref]

7. Ashraf, M., Gardner, L., & Nethercot, D. A. (2008). Structural Stainless-Steel Design: Resistance Based on Deformation Capacity. Journal of Structural Engineering, 134(3), 402–411. https://doi.org/10.1061/(asce)0733-9445(2008)134:3(402) [Google Scholar] [Crossref]

8. Asioro F. U. and Udo U. C. (2013). Development of Motorized Oil Palm Fruit Rotary Digester. Nigerian Journal of Technology, 32 (3), 455-462 [Google Scholar] [Crossref]

9. Babatunde, O. O., Ige, M. T., and Makanjuola, G. A., (1988). Effect of sterilization on fruit recovery in oil palm fruit processing. Journal of Agricultural Engineering Research, vol. 41, Issue 2, pp. 75-79. [Google Scholar] [Crossref]

10. Bello R. S., Bello M. B., Essien B. A., Saidu M. J., (2015). Economic Potentials of Oil Palm Production and Machinery Use in UDI, Enugu State, Nigeria, Science Journal of Business and Management. Special Issue: Sustainable Entrepreneurial Developments in Agribusiness. Vol. 3, No.5-1, pp. 16- 20. [Google Scholar] [Crossref]

11. Cornet, R.C.(2001) ). Introduction Nutritional Aspects of Palm Oil. American Journal of clinical nutrition 53: 989S – 1009S. [Google Scholar] [Crossref]

12. Erhimona, G.O., and Onyenanu, I.U (2023). International Journal of Engineering Research & Technology (IJERT) ISSN: 2278-0181 http://www.ijert.org IJERTV12IS070009 Vol. 12 Issue 07 [Google Scholar] [Crossref]

13. Ibiyeye, D., Dlunloyo, O., Aderemi, A., Emmanuel, I., Akala, A., and Owolola, O. (2022). Design and development of a palm kernel nut unit. Technology audit and Production Reserves, 1/3(63), pp. 30-44, doi:http://doi.org/10.15587/2706-5448.2022.253931. [Google Scholar] [Crossref]

14. Ibrahim A and Onwalu A.P. (2005). Technologies for Extraction of Oil from oil Bearing Agricultural Products: A Review. Journal of agricultural Engineering and Technology vol 13 pp58-89. [Google Scholar] [Crossref]

15. Ibrahim, 1 D., Jamıru, J., Sofuwa, O., and Onuoba, O. J., (2016). Design and performance evaluation of horizontal-shaft palm kernel cracking machine. Proceeding of Covenant University 3rd International Conference on African Development. Issues. pp. 337-3341. [Google Scholar] [Crossref]

16. Ibrahim, O. A., Uche, C., Mahdi, M., Michael, C. A., and Sylvester, G. (2017). Dense medium machine processing method for palm kernel/shell separation. Journal of Applied Science and Environmental Management. Vol. 21(7), pp 1336-1340. , [Google Scholar] [Crossref]

17. Jain, R. K. and Bal, S. (1997). “Properties of pearl millet”, Journal of Agricultural Engineering Research, vol. 66, pp. 85–91. [Google Scholar] [Crossref]

18. John S., Attahiru H., and Aliyu Y. (2020). Development of a Palm kernel cracking and separator machine. International Journal of Agricultural Science and Technology, vol. 8 No. 4 pp. 47-59. www.iarcj.org, www.arsnjournals. [Google Scholar] [Crossref]

19. Nwankwojike B. N, Odukwe A. O. and Agunwamba J. C.(2011). “Modification of Sequence of Unit Operations in Mechanized Palm Fruit Processing”, Nigerian Journal of Technology, Vol. 30, No. 3, pp. 41-49. [Google Scholar] [Crossref]

20. Offiong A.A., Offiong, A., Aondona, P.T., and Ihom, A.P. (2025) Design and Production of aVertical Palm Fruit Digester, Hollex Journal of Engineering and Innovation, 13(4), 16-47. [Google Scholar] [Crossref]

21. Ogblechi S. R and Ige M. T. (2014). “Development of a Model to Predict the Shear Force of a Horizontal Mechanical Digester”, International Journal of Science, Technology and Society, Vol. 2, No. 6, pp. 174-178. [Google Scholar] [Crossref]

22. Udo, S. B., Adisa, A. F., Ismila, S. O, and Adejujyibe, S. B., (2015). Development of palm kernel nut cracking machine for rural use. Agric Eng Int: CIGR Journal 17(14): 379- 388. [Google Scholar] [Crossref]

23. Uzoma, S. M. and Eseonu O. (2024). Design and Fabrication Details of an improved mechanized palm fruit harvester. American Journal of Mechanical Engineering, vol. 12, No. 2, pp 19-25. Available online at http://pubs.sciepub.com/ajme/12/2/2022 [Google Scholar] [Crossref]

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