With the gradual implementation of national energy-saving and emission reduction measures, the call for environmental protection is rising, and harmless treatment of waste is imperative.

　　Luan City, Anhui Province, is in a rapid stage of urbanization, with the cityscape changing daily; however, at the same time, the explosive growth of the urban population inevitably leads to more sewage discharge, putting increasing purification pressure on the municipal system. The Chengbei Sewage Treatment Plant, located on the city's outskirts, treats 80,000 tons of urban domestic sewage daily, making an indelible contribution to the city's environmental purification. During operation, the treated sewage is discharged into the urban water network after purification, while the sedimented sludge from the sewage is directed to a specialized activated sand filter pool for further anaerobic fermentation treatment. The treated sludge is disinfected and sterilized to produce flower mud, which is used for urban greening and planting.

　　However, during the anaerobic fermentation of sludge, a large amount of biogas is produced, mainly composed of methane, which is a major greenhouse gas. The greenhouse effect of methane is 25 times that of carbon dioxide. If untreated, it will cause more severe environmental damage. This project uses three 375kW biogas generator sets to generate electricity from biogas, which are connected in parallel to the grid. Besides using part of the electricity on-site, the rest is sold to the grid, which is the main source of income for the treatment plant. Moreover, the project adopts a CHP (Combined Heat and Power) application mode, recovering waste heat from the engine cylinder water and exhaust during power generation. The recovered hot water is used to heat the fermentation tanks, not only improving fermentation efficiency but also ensuring the stability of gas composition and gas production.

　　The unit uses Perkins 4006-23TRS2 biogas engines, employing advanced combustion technology and engine structure, which improves fuel efficiency while ensuring engine reliability and durability; the engine maintenance interval can reach 1500 hours, reducing labor costs for management personnel and significantly lowering spare parts consumption expenses, maximizing customer benefits. Additionally, the engine maintenance operation is simple and easy to understand. During the commissioning and acceptance phase, Perkins commissioning engineers provided detailed maintenance operation training to management personnel, combining theoretical explanations with hands-on practice, enabling on-site staff to proficiently perform basic engine maintenance operations.

　　Since the unit was put into operation in 2019, it has been running stably and safely, bringing stable and considerable benefits to customers and receiving full recognition from them; while expanding the environmental protection market, it has also enhanced Perkins' reputation in the Chinese market.

　　Energy saving and emission reduction, I am with you, working together to protect the green mountains, clear waters, and blue sky.