Zhejiang Satellite Petrochemical — PSA (2019) — Hydrogen-Rich Gas Compression for PSA Purification
By Qiangbin Chu · Sales Manager & Operations Lead
Zhejiang Satellite Petrochemical operates large-scale propane dehydrogenation (PDH) and ethane cracking facilities that produce significant volumes of hydrogen as a by-product. PSA (Pressure Swing Adsorption) units purify this hydrogen for use in hydrogenation, hydrotreating, and other downstream processes. The PSA process generates a tail gas rich in hydrogen (71.7% H2) mixed with methane, ethane, and other light hydrocarbons that still has substantial economic value.
| Client | Zhejiang Satellite Petrochemical Co., Ltd. |
| Plant / Unit | PSA — Pressure Swing Adsorption |
| Equipment | Gas Compression Package × 1 |
| Design Code | GB |
| Motor Power | 630 kW |
| Gas Composition | 71.7% H2 (hydrogen-rich mixture) |
| Design Institute | Shandong Qilu Petrochemical Engineering Co., Ltd. |
| Year | 2019 |
Customer Background
Zhejiang Satellite Petrochemical operates large-scale propane dehydrogenation (PDH) and ethane cracking facilities that produce significant volumes of hydrogen as a by-product. PSA (Pressure Swing Adsorption) units purify this hydrogen for use in hydrogenation, hydrotreating, and other downstream processes. The PSA process generates a tail gas rich in hydrogen (71.7% H2) mixed with methane, ethane, and other light hydrocarbons that still has substantial economic value.
Rather than burning this tail gas as fuel, compressing it and routing it back through the PSA system or to other hydrogen consumers maximizes hydrogen recovery and improves overall plant economics. The gas compression package bridges the pressure gap between the low-pressure PSA tail gas and the required feed pressure for re-processing.
Hydrogen demand within the Satellite Petrochemical complex is substantial, with hydrogenation and hydrotreating units consuming large volumes of purified hydrogen. Maximizing hydrogen recovery from PSA tail gas reduces the need for dedicated hydrogen production, lowering both operating costs and the facility’s carbon footprint.
Challenges and Engineering Requirements
System Integration and Package Design
Compressor packages are not standalone machines — they are integrated systems combining the compressor, driver, interstage coolers, separators, control panels, piping, and instrumentation on a common skid frame. Every component must be engineered to work together: gas flow paths optimized to minimize pressure losses, vibration isolation designed to prevent resonance between rotating equipment and the skid structure, and control logic programmed to protect the compressor across all operating conditions.
Process Gas Compatibility
Compressing Gas Compression Package × 1 service in the petrochemical processing sector requires materials and seal systems compatible with the specific gas composition, including trace contaminants that can cause accelerated corrosion, elastomer degradation, or lubricant breakdown. The design must address gas properties at each compression stage — temperature rise, condensation risk, and molecular weight changes for gas mixtures.
Noise, Vibration, and Mechanical Integrity
Reciprocating and screw compressors generate significant dynamic forces that propagate through the skid structure to the foundation. The package design must account for pulsation dampening, piping flexibility analysis, and anchor bolt sizing to prevent fatigue failures in connected piping and instrumentation. Acoustic enclosures or silencers may be required to meet plant noise limits.
Why Zhejiang Satellite Petrochemical Co., Ltd. Selected Lmart
Turnkey package engineering. Lmart provides complete compressor package engineering including process simulation, mechanical design, structural analysis of the skid frame, piping stress analysis, and control system programming — delivered as a factory-tested, ready-to-install module.
Multi-gas experience. Lmart has delivered compression packages for natural gas, BOG (boil-off gas), propylene, hydrogen, chloromethane, and other process gases, each with its own material compatibility, seal technology, and safety requirements.
Workshop integration and testing. Complete packages are assembled, piped, wired, and functionally tested at Lmart’s facility before shipment. Factory acceptance testing includes mechanical run tests, control loop verification, and safety system validation.
Technical Scope and Specifications
The compression package compresses hydrogen-rich PSA tail gas (71.7% H2) from the PSA unit’s low-pressure desorption outlet to the required delivery pressure. The 630 kW motor drives a screw compressor selected for the specific gas properties of the hydrogen-rich mixture.
Key design considerations:
- Hydrogen-rich gas handling: At 71.7% H2, the gas has a very low molecular weight (approximately 5–6 g/mol), which affects compressor volumetric efficiency, discharge temperature, and seal leakage rates compared to heavier hydrocarbon gases
- Low molecular weight challenges: Hydrogen’s small molecular size increases internal leakage through clearances in screw compressors, requiring tighter manufacturing tolerances and careful rotor profile selection to maintain efficiency
- High discharge temperature: The high ratio of specific heats (k value) for hydrogen-rich gas produces elevated discharge temperatures, requiring adequate intercooling and temperature monitoring
- Flammable gas service: Hydrogen is flammable with a very wide explosive range (4–75% in air), requiring stringent safety measures including gas detection, purge systems, and explosion-proof electrical equipment
- Qilu Petrochemical Engineering specifications: Equipment designed per Shandong Qilu’s standards for PSA integration, including process control interlocks with the upstream adsorption cycle
This was the third project Lmart delivered for Satellite Petrochemical, following propylene BOG (2017) and LPG BOG (2018) compression packages. The progression from hydrocarbon BOG to hydrogen-rich gas compression demonstrates the range of Lmart’s compressor package capability across different gas services.
Delivery and Quality Assurance
The compression package was factory-assembled and tested at Lmart’s Zhangjiagang facility. Given the hydrogen-rich gas service, particular attention was paid to leak testing of all flanged connections, valve packing, and shaft seals. The package underwent mechanical run testing with vibration monitoring, discharge temperature verification, and complete instrument loop checks. All pressure vessels were hydro-tested per GB 150, and material certificates were verified for hydrogen service suitability.
Documentation was prepared to Shandong Qilu Petrochemical Engineering’s specifications, including process flow diagrams, equipment data sheets, and operating and maintenance manuals. The PSA compression package was integrated with the existing hydrogen recovery system at Satellite Petrochemical’s facility, completing the third phase of Lmart’s equipment supply to this customer.
Results and Business Impact
Lmart successfully delivered 1 units of Gas Compression Package × 1 to Zhejiang Satellite Petrochemical Co., Ltd., meeting the project’s quality, schedule, and documentation requirements. The equipment was manufactured to GB standards, with full documentation packages accepted by the client and applicable inspection authorities.
This project reinforces Lmart’s position as a qualified manufacturer for petrochemical processing applications, demonstrating the company’s ability to deliver equipment that meets international quality and certification standards.
Deepen Your Knowledge
Customer Voice
“The equipment was delivered on schedule and the documentation package was complete. The quality of fabrication met our inspection requirements.”
— Zhejiang Satellite Petrochemical Co., Ltd. project team (paraphrased from project review)
Note: Lmart respects client confidentiality. Specific contact references are available upon request during the qualification process.