Lianyungang Petrochemical — HDPE (2019) — 2,200 kW Ethane Cooling System with n-Hexane/Iso-Hexane Coolant

Lianyungang Petrochemical Co., Ltd. is a major petrochemical producer in Lianyungang, Jiangsu Province, operating ethylene cracking and downstream polyolefin units as part of one of eastern China's key petrochemical bases. The HDPE unit employs slurry-loop polymerization technology — a process where ethylene is polymerized in a liquid hexane diluent within a continuous loop reactor at pressures of 30–40 bar.

Customer	Lianyungang Petrochemical Co., Ltd.
Plant / Unit	HDPE (High-Density Polyethylene)
Equipment	Ethane Cooling Compressor Package
Design Institute	SEI (Sinopec Engineering Incorporated)
Design Code	GB
Cooling Capacity	2,200 kW per unit
Motor Power	800 kW + 315 kW
Refrigerant	R1270 (Propylene)
Coolant	n-Hexane / iso-hexane
Quantity	2 sets

Customer Background

Lianyungang Petrochemical Co., Ltd. is a major petrochemical producer in Lianyungang, Jiangsu Province, operating ethylene cracking and downstream polyolefin units as part of one of eastern China’s key petrochemical bases. The HDPE unit employs slurry-loop polymerization technology — a process where ethylene is polymerized in a liquid hexane diluent within a continuous loop reactor at pressures of 30–40 bar.

In slurry-loop HDPE production, hexane solvents (n-hexane and iso-hexane) serve as the reaction diluent and must be continuously cooled, recovered, and recycled. Additionally, ethane-rich gas from the reactor flash and recycle systems must be condensed and returned to the process. The refrigeration system providing this cooling is integral to the reactor’s mass and energy balance — insufficient cooling capacity forces a reduction in reactor throughput.

Challenges and Engineering Requirements

Process Temperature Control in petrochemical processing

Lianyungang Petrochemical Co., Ltd. required precise low-temperature cooling for Ethane Cooling Compressor Package service in the petrochemical processing sector. The brine chiller system must maintain stable outlet temperatures within narrow tolerances despite variable process heat loads. Fluctuations in feed composition, ambient temperature swings, and seasonal load variations all affect the refrigeration duty — the system must respond to these changes while protecting compressor operation from surge and liquid carryover.

Refrigerant Selection and Safety

The choice of R1270 (Propylene) reflects the balance between thermodynamic efficiency at the target evaporating temperature, compatibility with the plant’s existing refrigerant infrastructure, and safety classification under the applicable code. Each refrigerant brings specific considerations: flammability limits for hydrocarbon refrigerants, operating pressure ranges that affect component sizing, and oil miscibility that influences compressor lubrication system design.

Integration with EPC Engineering

The chiller packages were specified and documented by SEI (Sinopec Engineering Incorporated) as part of a larger process unit. This means every interface — brine supply/return connections, electrical load requirements, control signal protocols, and physical footprint — must match the EPC’s plot plan and P&ID exactly. Any deviation requires formal design change management, adding time and cost to the project.

Why Lianyungang Petrochemical Co., Ltd. Selected Lmart

Integrated refrigeration package capability. Lmart designs and manufactures complete refrigeration systems — compressor selection, heat exchanger sizing, piping layout, control logic, and skid-frame engineering — as a single-source supplier. This eliminates the interface risks that arise when the chiller vendor, vessel fabricator, and system integrator are separate companies.

Process refrigerant experience. Lmart has delivered refrigeration packages using propylene, propane, ammonia, R134a, and other process refrigerants across petrochemical, chemical, and marine applications. This experience base means the engineering team understands the specific requirements of each refrigerant — safety classifications, oil management, capacity control methods — without a learning curve.

Repeat performance. Lmart has delivered equipment to Lianyungang Petrochemical Co., Ltd. and similar clients in the petrochemical processing sector, demonstrating consistent quality and on-time delivery performance across multiple projects.

Engineering and Manufacturing Solution

Lmart engineered and fabricated Ethane Cooling Compressor Package for Lianyungang Petrochemical Co., Ltd. to GB. The scope of supply included complete detail design, material procurement, fabrication, inspection, testing, and documentation.

Key engineering considerations for this project included thermal-hydraulic performance optimization, material selection for the specific process environment, and compliance with GB requirements for design, fabrication, and inspection.

The equipment was manufactured at Lmart’s Zhangjiagang facility, which provides full-cycle fabrication capabilities including plate rolling, head forming, machining, welding (SAW, GTAW, SMAW), post-weld heat treatment, and NDE — all under a single quality management system.

Delivery and Outcome

Both packages were delivered to the Lianyungang site and commissioned with the HDPE unit. Lmart also supplied an ethylene liquefaction package (1,000 kW) to the same client’s ethylene tank farm in the same year, demonstrating multi-unit supply capability across different process applications at a single petrochemical site. The successful operation of these units at Lianyungang, alongside similar HDPE cooling packages delivered to Hengli Petrochemical (2018) and Sinopec Zhenhai (2020), establishes Lmart as a proven supplier for polyolefin reactor cooling systems designed by SEI.

Results and Business Impact

Lmart successfully delivered Ethane Cooling Compressor Package to Lianyungang 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.

Customer Voice

“The equipment was delivered on schedule and the documentation package was complete. The quality of fabrication met our inspection requirements.”

— Lianyungang 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.