General knowledge on biogas power generation

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1. Why generate electricity from biogas? What are the significant advantages of biogas power generation? Biogas power generation is a new energy utilization technology that combines environmental protection and energy conservation. It utilizes biogas generated through anaerobic fermentation of large amounts of organic waste from industrial, agricultural, or urban activities (such as distillers’ grains, livestock manure, municipal waste, and sewage) to power biogas generator sets. The waste heat produced by these generator sets can also be utilized for biogas production, resulting in an overall thermal efficiency of around 80% – which is higher than the typical efficiency of 30–40% for conventional power generation methods, thereby bringing significant economic benefits to users. 2. What are the requirements for biogas in biogas power generation? The content of impurities in biogas, such as Si and HS, should be kept within certain limits. The temperature of biogas ranges from 10 to 60 °C, while its pressure is between 0 and 5 kPa; specific requirements can be found in the specifications for biogas quality. Generally, biogas produced from the anaerobic treatment of animal and poultry manure meets the requirements for use in power generation. Biogas generated from sewage treatment requires desulfurization, whereas biogas from landfill disposal needs dehydration. 3. Can the electricity generated be connected to a grid transformer of 6300V or 10000V? Does the power grid allow it? The output voltage of the biogas generator set is 400V; it can be connected to the low-voltage side of transformers with a voltage of 6300V or 10000V. If the low-voltage circuit is long, the 400V voltage can be stepped up to 6300V in order to connect to the power supply grid ； If power is not fed back into the grid, inverse power relay protection is used to prevent power from being fed back into the grid, which has no impact on the safety of grid operation. The power supply authority will not question this method of power generation. 4. Can electricity be generated when the biogas concentration changes? The generator set can operate as usual; after adjustment, it can generate power normally or reduce its power output. 5. What are the requirements for the plant space for power generation equipment? Two 500KW generator sets provide a total power output of 1000KW. The area required for the plant (including the compressor room, control room, and duty room) is around 200 square meters; a standard plant structure will suffice. 6. How long is the payback period for biogas power generation equipment? The investment in all auxiliary equipment, including generator sets, results in a payback period of 8 months if the electricity cost is 0.6 yuan per kilowatt-hour; around 10 months if the cost is 0.5 yuan per kilowatt-hour; and 12 months if the cost is 0.4 yuan per kilowatt-hour. 7. 7. How much electricity can be generated from biogas? What is the operating cost per unit of electricity (overhaul costs, financial expenses, equipment depreciation)? How long does a device run in a year? For a 500KW generator set, how much electricity is generated and fed into the grid per month? How long does it take for a piece of equipment to require major maintenance? How long does it take for a major overhaul? How much is it? The power output on one side is around 1.7 KW.hr (assuming a methane concentration of 50% in the biogas). The operating cost per kilowatt-hour (including major repair costs, financial expenses, and depreciation costs) is 0.04 – 0.05 yuan. The equipment operates for over 7,200 hours per year. A 500KW generator set generates over 250,000 kWh of electricity per month. A device undergoes a major repair every three years, with the cost at around 70,000 yuan per repair. The major repair will take approximately 15 to 25 days. 8. How many equipment operators are needed? For 1 to 3 units, 1 to 2 personnel are required per shift, along with 1 maintenance worker. 9. How long is the service life of biogas generator sets? It has a service life of over 20 years, with an actual online power generation time of more than 7,200 hours per year.