Zhejiang Petrochemical — Butadiene (2020) — 880 kW Brine Chiller for Butadiene Extraction
By Qiangbin Chu · Sales Manager & Operations Lead
The butadiene unit at Zhejiang Petroleum & Chemical extracts 1,3-butadiene from the C4 fraction of the steam cracker via extractive distillation using a selective solvent (typically NMP or DMF). Butadiene is a critical monomer for synthetic rubber (SBR, polybutadiene, nitrile rubber) and ABS resin production — materials essential to the automotive tire, consumer electronics, and construction industries.
| Customer | Zhejiang Petroleum & Chemical Co., Ltd. |
| Plant / Unit | Butadiene Extraction |
| Equipment | Brine Chiller Package |
| Design Institute | HQC (Guangdong) |
| Design Code | GB |
| Cooling Capacity | 880 kW |
| Motor Power | 560 kW |
| Refrigerant | R1270 (Propylene) |
| Coolant | Ethylene glycol |
| Quantity | 1 set |
Customer Background
The butadiene unit at Zhejiang Petroleum & Chemical extracts 1,3-butadiene from the C4 fraction of the steam cracker via extractive distillation using a selective solvent (typically NMP or DMF). Butadiene is a critical monomer for synthetic rubber (SBR, polybutadiene, nitrile rubber) and ABS resin production — materials essential to the automotive tire, consumer electronics, and construction industries.
The extraction process requires low-temperature cooling at multiple points: the extractive distillation column overhead condenser, the solvent recovery section, and the product purification column. Butadiene must be separated from closely boiling C4 hydrocarbons (1-butene, 2-butene, isobutylene, n-butane) whose boiling points differ by only a few degrees. Tight temperature control in the condensation and fractionation stages directly affects product purity (≥99.5% typical specification) and recovery yield.
Challenges and Engineering Requirements
Process Temperature Control in petrochemical processing
Zhejiang Petroleum & Chemical Co., Ltd. required precise low-temperature cooling for Brine Chiller 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 HQC (Guangdong) 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 Zhejiang Petroleum & Chemical 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 Zhejiang Petroleum & Chemical 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 Brine Chiller Package for Zhejiang Petroleum & Chemical 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.
Package Scope and Quality
The brine chiller package was delivered as a complete factory-assembled skid including the screw compressor, shell-and-tube evaporator, condenser, oil separator, economizer, electronic expansion valve, and integrated control panel with PLC and DCS interface. All pressure vessels were fabricated and tested per GB 150, with material certificates traceable to the original mill heat numbers.
The ethylene glycol circuit connections were designed for compatibility with the butadiene unit’s existing glycol distribution header, including standardized flange ratings, glycol concentration specification (typically 35–45% by weight for the target supply temperature), and flow/return temperature instrumentation for performance monitoring.
HQC (Guangdong)’s QC requirements included:
- Pressure vessel fabrication and hydrostatic testing per GB 150 for all heat exchangers and separators
- Compressor performance test at design evaporating and condensing temperatures
- Complete skid leak test and electrical loop test
- Safety interlock functional verification (high pressure, low pressure, high temperature, motor overload, gas leak detection)
- Documentation package including material certificates, weld records, test reports, and O&M manual
Results and Business Impact
Lmart successfully delivered Brine Chiller Package to Zhejiang Petroleum & Chemical 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 Petroleum & Chemical Co., Ltd. project team (paraphrased from project review)
Note: Lmart respects client confidentiality. Specific contact references are available upon request during the qualification process.