The first phase of the Guangxi Jianhui Paper Industry wastewater anaerobic treatment project has a biogas production of 25,000 m³/d, a hydrogen sulfide content of 10,000-35,000 ppm, and a methane content of about 60%-70%. Based on an average methane content of 65%, 1 m3 of biogas can generate 3.59 × 65% = 2.33 kW·h of electricity, and the daily biogas power generation is 25,000 × 2.33 = 58,250 kW·h. The hourly power generation is about 2,427 kW·h, and two 1,500KW biogas generator sets are selected for installation.
The biogas first enters the gas storage cabinet for buffering and storage, then the desulfurization system removes the hydrogen sulfide in it to meet the use requirements of the biogas generator set, and then it is transported to the intake pipe of the biogas generator set through the Roots blower for power generation. A dehydration device is set in front of the unit.
The voltage level of the biogas generator set is 10.5KV, and it is connected to the owner's 10KV system through an automatic grid-connected device. The high-temperature flue gas at the outlet of the biogas generator set is heat-exchanged through the waste heat recovery device to generate low-pressure steam, which is connected to the heating pipeline interface provided by the owner.
Based on the operation of two 1500kW generator sets, the annual operating time is 8000 hours, and the electricity price is calculated at 0.60 RMB, the total power generation is: 2400×8000h=19200000kW·h;
Power generation income: 19200000kW·h×0.60RMB=11,520,000 RMB.
Performance indicators of this project:
(1) The generated power is connected to the grid;
(2) SO2 and NOX related emissions meet local emission requirements.