Performance evaluation of dewatering systems for bio-digestate for developing countries

  • Ajay Kumar Jha Department of Mechanical and Aerospace Engineering, Pulchowk Campus, Institute of Engineering, Tribhuvan University, Kathmandu 44600, Nepal
  • Sujan Jojiju Department of Mechanical and Aerospace Engineering, Pulchowk Campus, Institute of Engineering, Tribhuvan University, Kathmandu 44600, Nepal
  • Hari Darlami Department of Mechanical and Aerospace Engineering, Pulchowk Campus, Institute of Engineering, Tribhuvan University, Kathmandu 44600, Nepal
  • Bijay Basnet Department of Mechanical Engineering, Kathmandu University, Dhulikhel 45210, Nepal
Ariticle ID: 1431
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Keywords: screw type dewatering system; bio-digestate; performance evaluation; liquid yield; extraction efficiency

Abstract

The performance evaluation of a screw type dewatering system for bio-digestate in Nepal demonstrates significant potential for improving the usability and efficiency of bio-digestate as a fertilizer. Remarkable modifications in the previous include a 5 HP motor running at 1440 RPM with a gear reduction ratio of 1:40, a spring assembly system at the outlet, and a fine sieve. Testing and performance analysis at different operating speeds using a variable frequency drive revealed an optimal performance at 8 RPM, where the system achieved a liquid yield of 92.02% and an extraction efficiency of 73.12%. The installation cost of the machine was NPR 384,000, with a payback period of 2 years, six months, and two days. The internal rate of return (IRR) was calculated at 28.53%, while the net present value (NPV) was NPR 179,006.35. This study indicates that operating the dewatering system at lower speeds may improve efficiency and effectiveness in the dewatering process. This makes the machine a viable option for producing organic fertilizer and addressing Nepal’s significant need for fertilizer.

References

[1] Gregor DZ, Viktor G. Anaerobic Treatment and Bio digestion from organic waste 2012. Available online: https://cdn.intechopen.com/pdfs/27154/InTech-Anaerobic_treatment_and_biogas_production_from_organic_waste.pdf (accessed on 7 May 2024).

[2] Karunanithi A. System analysis of de-watering process for treating biogas digestate. Research Gate; 2014.

[3] WECS. Nepal Energy Sector Synopsis Report 2022. WECS; 2022.

[4] National Planning Commission. The Fifteenth Plan Fiscal Year. National Planning Commission; 2020.

[5] Bonten L, Zwart K, Rietra R, et al. Bioslurry as a fertilizer. Research Gate; 2014.

[6] Kabeyi MJB, Olanrewaju OA. Biogas Production and Applications in the Sustainable Energy Transition. Journal of Energy. 2022; 2022: 1–43. doi: 10.1155/2022/8750221

[7] Mangone F, Ferreira J, Ferrari A, et al. Modelling and optimization of a geotextile dewatering tubes process. 28th European Symposium on Computer Aided Process Engineering. 2018; 1371–1376. doi: 10.1016/b978-0-444-64235-6.50240-0

[8] Gateway Structure SDN BHD. What is Sludge Dewatering and Its Usages & Benefits. Available online: https://gssb.com.my/what-sludge-dewatering-usages-benefits (accessed on 7 May 2024).

[9] Malav L, Kumar M, Khan SA, Kumar S. Biogas Slurry: Source of Nutrients for Eco-friendly Agriculture. Research Gate; 2015.

[10] Karki AB. Country Report on the Use of Bio-slurry in Nepal. In: Bibalex. Netherlands Development Organisation; 2006.

[11] Machinery L. Longzhong Machinery. Available online: https://www.lzzgchina.com/solutions/project-case/sludge-dewatering-methods.html#:~:text=There%20are%20various%20technologies%20for,presses%2C%20centrifuging%2C%20and%20geomembranes (accessed on 7 May 2024).

[12] GlobalSpec. Dewatering Equipment Selection Guide. Available online: https://www.globalspec.com/learnmore/manufacturing_process_equipment/filtration_separation_products/dewatering_equipment. (accessed on 7 May 2024).

[13] Ford M, Fleming R. Mechanical Solid-Liquid Separation of Livestock Manure. International Food Safety. 2002.

[14] EPA U. Emerging Technologies for Biosolids Management. US EPA; 2006.

[15] Australia WE. Advancement In Screw Press Technology And Advantages For Sludge Dewatering. Waterman Engineer Australia; 2023.

[16] Okafor B. Development of Palm Oil Extraction System. Research Gate; 2015.

[17] Yadav S, Jha AK, Darlami HB. Design and Improvement of Dewatering System Implemented for Biogas Slurry. International Journal for Multidisciplinary Research. 2023.

[18] Mudryk K, Frączek J, Jewiarz M, et al. Analysis of Mechanical Dewatering of Digestate. Agricultural Engineering. 2016; 20(4): 157-166. doi: 10.1515/agriceng-2016-0073

Published
2024-07-19
How to Cite
Jha, A. K., Jojiju, S., Darlami, H., & Basnet, B. (2024). Performance evaluation of dewatering systems for bio-digestate for developing countries. Energy Storage and Conversion, 2(3), 1431. https://doi.org/10.59400/esc.v2i3.1431
Section
Article