Active Member
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[China]
Address: No. 3111, Huaning Road, Shanghai, 201108, P. R. China
Contact name:Tan Ling
Shanghai Marine Diesel Engine Research Institute |
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Absorption-membrane-Adsorption Technology for Vapor Recovery Unit
Summary
Vapor Recovery Unit is to collect the organic vapor discharged during the manufacturing, storage, loading and unloading processes of various industries and recycle it by means of condensation, adsorption, absorption, membrane separation, etc. so as to finally satisfy the emission standards and create certain economic benefits for the end user.
The Membrane Separation Process separates different composition taking advantage of their ability of penetrating the membrane. The Absorption–membrane–Adsorption Technology is suitable for treatment of medium to high concentration oil vapor, with no limitation to flow volume and vapor types. It is featured by small footprint.
Principle / Flow Procedure
The Membrane Separation Process separates different compositions taking advantage of different diffusion coefficient in membrane. As special polymeric membrane allows oil vapor to penetrate first, when the gas mixture is driven by pressure difference, the oil vapor penetrates the membrane and get recovered while air or nitrogen is blocked.
The associated gas is pressurized by a liquid ring compressor and led into the absorption tower for touch with the opposite flowing absorbent, then most of hydrocarbon composition shall be dissolved and absorbed;
The oil gas mixture pressurized by liquid ring compressor flows into the absorption tower and is exposed to absorbent flowing in opposite direction, where most hydrocarbon compositions are dissolved and absorbed. The remaining oil gas mixture of low concentration flows out of the tower from the top and enters the membrane system. High concentration oil gas penetrating the membrane returns to the absorption tower, while the air or nitrogen containing little oil vapor blocked by the membrane is delivered into small adsorption tank for further treatment. The Desorption Process adopts the dry screw vacuum pump for vacuum desorption. The oil vapor desorbed will be led into the absorption tower for further treatment.
Structure & Parameter (typical project)
| Application | Vapor recovery |
| Equipment name | Vapor Recovery Unit |
| Model | QY/VR series |
| Capacity | 200-5000 m3/h |
| Structure | Skid-mounted |
| Material | Carbon steel |
| Fabrication code | GB150.1～4-2011 |
| Design code | GB50759-2012 Q/SH0117-2007 |
| Design pressure | Micro positive pressure |
| Design temperature | Ambient |
| Applicable exhaust gas | Medium-high concentration oil vapor |
| Type of membrane | Organic composite membrane |
| Type of compressor | Liquid ring type |
| Type of vacuum pump | Dry screw vacuum pump |
| Type of absorption tower | Atmospheric pressure packed tower |
| Type of packing | High efficiency structured packing |
| Type of adsorption tank | Vertical atmospheric pressure tank |
| Type of adsorption | Coal-base activated carbon |
| Control method | PLC automatic control |
| Main measuring points | Pressure signal, level signal, flow signal, temperature signal |
| Main interlocked alarm system | Pressure signal for interlocked blower start-up/shut down; Level signal for interlocked drain pump start-up/shut down; Flow signal to control opening of absorbent liquid valve; Temperature alarm for interlocked emergency shut down; Concentration alarm of flammable or toxic gas |
| Type of connection | Bolted |
| Type of seal | Flange |
| Utility consumption | Instrument air: ≤10Nm3/h Absorption liquid: relevant to capacity; Nitrogen: for purge Electricity |
| Emission | Benzene ≤ 4mg/m3, Toluene ≤ 15mg/m3, Xylene ≤ 20mg/m3, Ethylbenzene ≤ 100mg/m3, Acetonitrile ≤ 50mg/m3; Non-methane total hydrocarbons: - Removal rate ≥ 97%, Concentration of emission ≤ 120mg/m3 |
| Noise | ≤ 85dB (A) |
| Height of exhaust gas funnel | 15 m |
| Service life | 25 years |
| Membrane life | 3 years |
| Activated carbon life | 8 years |
| Spare parts | Available for 2 years |
| Warranty | 12 months since start-up or 18 months since arrival of equipment |
| Scope of work / service | Full equipment package, supervision for site installation & commissioning, training for operation |
| Response upon request | Within 12 hrs |
Advantage
Applied data for an typical project
Benzene ≤ 4mg/m3,
Toluene ≤ 15mg/m3,
Xylene ≤ 20mg/m3,
Ethylbenzene ≤ 100mg/m3,
Acetonitrile ≤ 50mg/m3;
Non-methane total hydrocarbons:
---Removal rate ≥ 97%,
----Concentration of emission ≤ 120mg/m3;
Noise (1m from VRU): ≤ 85dB (A)
Height of exhaust port: ≥ 15m.
