Project informations:
Project of landfill gas
Xiaping, Luohu District, Shenzhen, Guangdong, China
Gas collecting system from Landfill
1,300 Nm³/hr Skid-mounted Biogas pre-treatment system
GE Waukesha APG 1MW × 2
Our GasPro system is for the pre-treatment of landfill gas or desulphurized biogas of other sources, suitable for gas flow 300 ~ 5,000 Nm³/hr, with main functions of dehydration, dehumidification, edulcoration, boosting, pressure-stabilization, thermoregulation, automatic/remote controlling and on-line detecting,etc.
a. Filtration; Physical particles could be observably removed;
b. Multi-stage dehydration could reduce the temperature of gas dew point,as well as the water vapor content;
c. Freezing function for condensation and precipitation of harmful gases;
d. Adjusting gas temperature in proper condition to feed engine;
e. On-line detecting system for measuring gas composition timely(optional);
f. Advanced control system could stabilize the gas outlet pressure and temperature;
g. The gas flow is automatically tracked rooted on the requirements of engine;
h. Equipped with alarms and protections for over-pressure and over-temperature, to ensure safe and reliable operation of system in the long-term;
i. This matched system could make engine runs under condition of fixed thermal value, to improve the stability of engine operation and protect the gas collector.
The technological process of GasPro system:
The landfill gas or other biogas, after cleaned through our GasPro system, could be in a proper condition for the use of generators. The stability of outlet pressure can be realized through the combined effects of automatic control system and blower.
Flow-chart of GasPro system for converting landfill gas:
1. Dehydration, Dehumidification, Edulcoration
The relative humidity of raw landfill gas is 100% to be fed to GasPro system. Through the high efficient primary filter, water spray and physical impurities are removed, water content becomes saturated and dust size less than 50μm, meanwhile the hydrogen sulfide, ammonia and other harmful gases are dissolved in the condensate, to be discharged out of system.
Subsequently, the saturated gas goes into deep cooling system. Its temperature drops down to 10~15 degree.C after cooled in the shell and tube heat exchanger. The moisture, dust and harmful gases can be removed further in the condenser. The relative humidity of gas gets out of condenser could reach 80% or even lower to satisfy the requirement of generator on water content.
The separation of condensate water occurs in the gas-water separator.
2. Pressure increasing, Pressure stabilizing and Thermoregulation
Pressure increasingTaking into considering the gas refining, the need of power generation and investment control, commercial solution is the use of roots blower for gas delivery and meeting the requirement of inlet pressure of generator.Pressure stabilizingRoots blower is controlled by frequency converter. The gas pressure signal from outlet of system is fed back to PLC, to regulate the output current of frequency converter, to change the speed of motor of roots blower, by this means to regulate the gas flow in the range of 20 ~ 100%. Not only the manifold pressure can be stabilized, but also the power consumption of system could be regulated in accordance with the load fluctuation, to avoid the rise of power consumption of system.ThermoregulationThe cooled gas from condenser goes through roots blower, after that, its temperature would rise naturally. Then flows into air cooler for cooling again. In this way, the gas temperature would be adjusted well to be fed to generator.
3. Secondary Filtration
The final step of GasPro system is the secondary filter. Filter element is stainless steel material, with enough filtrating area. The micro-sized impurities could be effectively removed, to achieve the purpose of fine separation.
4. Automatic Drainage
Condensate water would be generated resulting from the cooling of the pipeline and equipment of GasPro system, and it can be discharged out of system automatically.
5. Automatic Controlling Process
GasPro system uses proframmable controller - PLC control, with functions of data acquisition, on-line detection and alarm. Standard communication interface to be provided in synchronization with the owner's control system per clients' requirements, to achieve the purpose of unattended and fully automatic operation:A programmable PLC controller for data acquisition and processing;With function of remote data transmission;Through standard industrial Ethernet to read data when system in operation;Site controlling mode at local engineering station by the use of LCD touch screen. Through data transmission to achieve the purpose of remote controlling, eg. start/stop signal;The use of professional computer for processing of data and signal. Configuration software and past records are stored in the hard risk of computer;Within authorized scope, engineer could modify the parameter settings of alarm and shutdown.