Economic Analysis of Biogas Production via Biogas Digester Made from Composite Material

• Published in: ChemEngineering
• Main Authors: KeChrist Obileke, Golden Makaka, Nwabunwanne Nwokolo, Edson L. Meyer, Patrick Mukumba
• Format: Article
• Language: English
• Published: MDPI AG 2022-09-01
• Subjects: composite materials; biogas; biogas digester; economic analysis; economic indicator
• Online Access: https://www.mdpi.com/2305-7084/6/5/67

This study seeks to evaluate the economic implication of a biogas digester built from composite material to ascertain its cost effectiveness. The feasibility study conducted indicates that a brick made only of fixed dome digester costs between USD 3193.99 and USD 4471.59. This high cost is attributed to the construction material, thus prompting the need to use materials of lower cost for affordability and sustainability. Hence, the digester under study was made from composite material comprising high-density polyethylene (HDPE), bricks and cement. The inlet and outlet chambers were built using bricks and cement, while the digestion chamber was made from HDPE material. From the economic analysis conducted, the total initial investment cost of the biogas digester was reported to be USD 1623.41 with an internal rate of return (IRR) of 8.5%, discount payback period (DPP) of 2 years and net present value (NPV) of USD 1783.10. The findings equally revealed that the estimated quantity of biogas could replace 33.2% of liquefied petroleum gas (LPG) cooking gas. Moreover, the biogas daily yield of 1.57 m³ generates approximately 9.42 kWh of electricity, which costs about USD 1.54. Thus, the study recommends the use of composite material of plastics and bricks in constructing the biogas digester, as it is cost effective and sustainable.