Process Principle

Both nitrogen and oxygen possess quadrupole moments. Since the quadrupole moment of nitrogen (0.31 Å) is much larger than that of oxygen (0.10 Å), molecular sieve exhibits stronger adsorption capacity for nitrogen than oxygen.

When compressed air passes through an adsorption bed filled with molecular sieve, nitrogen is adsorbed, while oxygen is less adsorbed and flows out, thereby achieving oxygen-nitrogen separation to produce oxygen. When nitrogen adsorption approaches saturation, air input is stopped and the pressure in the adsorption bed is reduced. The adsorbed nitrogen is then desorbed, regenerating the molecular sieve for reuse. The system adopts two adsorption towers: one produces oxygen via adsorption while the other undergoes desorption and regeneration, operating alternately in cycles for continuous oxygen production.

Technical Features

VPSA oxygen generation is based on oxygen-specific molecular sieve and adopts an advanced two-bed process flow. Blowers and vacuum pumps are supplied by first-tier manufacturers. After long-term screening of domestic and international products, Handa (Hunan) pneumatic butterfly valves are selected for their excellent sealing performance and reliable operation, supporting up to 2 million maintenance-free cycles.In actual application, seals can be used for 2 years without replacement.Tongyue Gas owns unique technologies including desorption process, reflux cleaning process, gradient pressure equalization process, as well as exclusive media filling and compression techniques.

Types of Adsorption Towers

1000Nm3 For flows below /h, an axial tower is recommended.	1000Nm3 For flows above /h, an axial tower is recommended.
The fluid flows axially through the adsorption tower from bottom to top.	Radial flow of the fluid from the outer to the inner adsorption tower

Radial Tower

Advanced tower structure with high manufacturing difficulty
Uniform molecular sieve bed with low flow resistance
Suitable for equipment up to 7500 Nm³/h

High-Frequency Valves

Valve Standards:

• Pneumatic butterfly valve switching speedLess than 1 second (at pilot air pressure 0.6 MPa)
• Pneumatic butterfly valve operating frequencyOnce per 20 seconds (each open or close counts as one operation) (at pilot air pressure 0.6 MPa)
• Service life of valve sealsBidirectional sealing: 2 million operations with zero leakage (bidirectional differential pressure 0.1 MPa)

Main Technical Parameters of VPSA Oxygen Generation (Purity 80%)

Specification Model	VP-500	VP-1000	VP-2000	VP-3000	VP-4500	VP-6250	VP-7500
Gas production rate Nm³/h	500	1000	2000	3000	4500	6250	7500
Voltage	10kv	10kv	10kv	10kv	10kv	10kv	10kv
Installed power (kW)	250	435	715	1120	1600	2240	2500
Valve air consumption m 3/min	1.0	1.5	2.0	3.0	5.0	6.0	6.5
Cooling water circulation rate m 3/h	20	40	80	110	120	130	140
Soft water consumption m 3/h	1.92	2.7	2.88	3.9	4.2	4.5	4.8

Main Technical Parameters of VPSA Oxygen Generation (Purity 93%)

Specification Model	VP-200	VP-300	VP-400	VP-500	VP-600	VP-800	VP-1000
Gas production volume Nm 3/h	200	300	400	500	600	800	1000
Voltage	380v	380v	380v	380v	380v	10kv	10kv
Installed power (kW)	120	165	200	270	317	380	450
Valve air consumption m 3/min	0.5	0.7	0.9	1.1	1.4	1.6	2.0
Cooling water circulation rate m³/h	11	15	20	26	30	38	55
Soft water consumption m 3/h	1.2	1.8	1.98	2.1	2.1	2.4	2.7

Main Technical Parameters of VPSA Oxygen Generation (Purity 93%)

Specification Model	VP-1200	VP-1600	VP-2000	VP-3000	VP-3600	VP-4500	VP-5500
Gas production volume Nm 3/h	1200	1600	2000	3000	3600	4500	5500
Voltage	10kv	10kv	10kv	10kv	10kv	10kv	10kv
Installed power (kW)	565	715	1000	1250	1600	2000	2500
Valve air consumption m 3/min	2.0	2.4	3.0	3.3	4.2	5.5	6.5
Cooling water circulation rate m 3/h	62	90	100	110	120	130	140
Soft water consumption m 3/h	2.7	2.88	3.3	3.6	4.2	4.5	4.8

Oxygen Generator Process Flow Diagram

► Tongyue oxygen generation system capacity: 100 ~ 7500 Nm³/h
► Standard conditions: 1 atm, 70 °F (21.11 °C), 0% relative humidity
► Under maximum plant capacity at standard conditions, power consumption is 0.3 kW·h per Nm³ of oxygen produced
► Normal conditions: 1 atm, 0 °C, 0% relative humidity

Comparison of VPSA Oxygen Production via Pressure Swing Adsorption with Other Process Routes

Content	VPSA	PSA	Cryogenic
Oxygen concentration	93%	93%	99.6%
Oxygen flow	80Nm3/h-7500Nm3/h	200Nm3 Less than /h	Can be designed at scale
By-product	None	None	Nitrogen, argon
Operating temperature	Ambient temperature and pressure	Ambient temperature and high pressure	-190℃ ultra-low temperature
Power consumption	0.48 degrees/Nm 3	0.8 degrees/Nm 3	0.8 degrees/Nm 3
Construction procedures	Simple	Simple	Cumbersome
Startup time	<0.5h	<0.5h	>48h
Operator	2–3 people	1 person	5–10 people
Equipment lifespan	10	5 years	10 years
Operation and Maintenance	Convenient	Convenient	Complex
Construction period	6 months	3 months	12 months

Calcium-based oxygen-producing molecular sieve

Indicator	Unit	Indicator Requirements
Particle size	%wt	≥95
N2 adsorption, 25°C, 1 bar	ml/g	≥25
Oxygen–nitrogen separation factor, 25°C, 1 bar	~	≥4.2
Compressive strength, average of 25 specimens	N pieces	≥15
Bulk density, tapped	g/ml	≥0.635
Conversion yield	Nm 3 /h·t	65~75

Lithium-based oxygen-generation molecular sieve

Indicator	Unit	Indicator Requirements
Particle size	%wt	≥95
N2 adsorption, 25°C, 1 bar	ml/g	≥23.5
Oxygen–nitrogen separation factor, 25°C, 1 bar	~	≥6.3
Compressive strength, average of 25 specimens	N pieces	≥25
Bulk density, tapped	g/ml	≥0.63
Conversion yield	Nm 3 /h·t	85~95

Both nitrogen and oxygen have quadrupole moments. Since the quadrupole moment of nitrogen (0.31 Å) is much larger than that of oxygen (0.10 Å), molecular sieve has a stronger adsorption capacity for nitrogen than for oxygen.