2025 Volume 16 Issue 1 Pages 1-7
Covered lagoon digesters are commonly used by commercial pig farms in Cambodia to manage their wastewater and produce biogas for electricity generation. In these biogas systems, dual or modified pure biogas generators are utilized, but the efficiency of different generators in the context of Cambodia has yet not been rigorously evaluated. Therefore, the current study aimed to (1) determine biogas production and quality in two pig farms, (2) compare the working performance of a pure biogas generator and a dual generator, and (3) estimate CO2 emission reduction in the two cases. The study was carried out between May 2022 and May 2023 on two large-scale pig farms that hosted fully operational biogas systems. The first farm operated an all-in-all-out system with 8,000 fattening pigs in Kampong Speu Province, while the second farm operated a full system with 5,000 fattening pigs and 600 sows. The portable biogas analyzer, electrical power logger, and a vortex flowmeter were used to measure biogas quality and record the power consumption and daily biogas production. The results show that the first farm produced 792 Nm3/day, whereas the second farm produced 495 Nm3/day of biogas daily. Additionally, the methane content in both cases was not significantly different (60% of CH4). However, the dual generator can generate power up to 1,118 kWh/day, while the pure biogas generator can produce only 743 kWh/day. The first farm that used the dual generator could save up to 80% of total power consumption, whereas the second farm could save only 24% due to a larger demand for electricity. Thus, the first farm (3,408.2 t CO2equ) could reduce greenhouse gas emissions more than the latter (697.8 t CO2equ). The results of the study suggest that using biogas from wastewater treatment to produce electricity reduces both electricity costs and greenhouse gas emissions.
