(1) Requirements on inlet temperature and pressure of Biogas
Pressure swing adsorption and membrane separation technology have the same requirements for inlet temperature and pressure of methane, both at normal temperature and 0.60-0.80MPa.
(2) Impurities Requirements for Biogas Import
Pressure swing adsorption technology requires that particle size of dust at biogas inlet is <1.0μM, the maximum mass concentration of dust is <5.0mg/m3.Membrane Separation Requirements Particle Size of Biogas Inlet Dust <0.1μM, the mass concentration of residual oil is less than 0.1mg/m3.
(3) Service life of separating material
The adsorbent life of pressure swing adsorption technology is usually not less than 15a, while that of membrane separation technology is usually less than 8A due to dust or residual oil contamination.
(4) Since pressure swing adsorption requires 5-7 steps in operation to complete an adsorption process, the solenoid valves on the top of the adsorption tower are frequently opened and closed, so the solenoid valves need to be replaced frequently.Membrane separation technology operates continuously and is simpler in maintenance and maintenance than pressure swing adsorption.
(5) CH4 content in export natural gas
Using pressure swing adsorption technology, the volume fraction of natural gas CH4 after adsorption and separation can reach 96% or higher, and the yield of CH4 after biogas purification is not less than 92%.By using membrane separation technology, the volume fraction of CH4 of natural gas after separation can reach about 95%, but the yield of CH4 after biogas purification is generally not higher than 92%.
(6) Cost of equipment and operating expenses
Due to the high cost of membrane separation equipment, the total cost of membrane separation technology is higher than that of pressure swing adsorption technology.For biogas of the same scale, the total cost of membrane separation technology is generally 1.2-1.3 times that of PSA technology, and the
