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Aug 24, 2025 – The integrated refining and petrochemical Daxie complex | Credit: CGTN

Refinery History and Development

CNOOC Ningbo Daxie Petrochemical Co., Ltd. was established on December 31, 2001, and commenced operations in 2003 with a 500,000 tons per year road asphalt production facility. The company underwent corporate restructuring in 2005 and merged with CNOOC Zhoushan Petrochemical in 2009 through equity acquisition. The facility evolved from a specialty asphalt producer into an integrated refining and petrochemical complex through successive capacity expansions over two decades.

Capacity Development Stages

Phase 1 (2003-2015): Initial Operations
Initial operations focused on specialty products with 8 million tons per year crude processing capacity (160,000 b/d ADU) established by 2015. The facility operated basic refining units including atmospheric and vacuum distillation, producing primarily transportation fuels and specialty asphalt products.

Phase 2 (2013-July 2016): Major Distillate Oil Comprehensive Utilization Project
CNOOC completed a substantial $2 billion (13 billion yuan) expansion, adding 15 new specialized production units and boosting annual production capacity of finished products to 7 million tons. Construction began in 2013; key units commissioned in July 2016 included:

• Deep Catalytic Cracking (DCC-Plus) complex sized for ~2.2 Mt/a heavy oil/VGO feed, designed propylene output ~420,000 t/y
• Gas fractionation unit ~1.0 Mt/a
• Ethylbenzene/styrene: 300,000 t/a EB and 280,000 t/a SM.
• Continuous catalytic reforming (CCR) unit: large-scale based on domestic technology
• Diesel hydrotreating (HDT) unit 
• Wax oil hydrotreating (HDT) unit
• Supporting facilities including product storage and utility systems

The project achieved 96% domestic equipment adoption rate and enabled production of nearly 20 different chemical products plus diesel and jet fuel, with annual output of aromatics exceeding 1.5 Mt/a and propylene reaching 420,000 t/a.

Phase 3 (2020–2022): Polypropylene Complex
Engineering and construction of a 300,000 t/a polypropylene plant (using CB&I/Lummus Novolen gas-phase technology) were carried out through 2020–2022. The facility achieved mechanical completion and commercial startup in August–September 2022. This unit is supplied with propylene primarily from the 2.2 million t/a DCC-Plus complex.

Phase 4 (2022-2025): Integrated Refining and Petrochemical Complex
The major expansion project increased crude processing capacity from 8 to 12 million tons per year through a $2.9 billion investment. Construction began in 2022 with commercial operations achieved in August 2025. This phase added 18 new production units including:

• Crude processing uni (ADU + VDU): 6 Mt/a
• Catalytic Cracking Unit DCC-Pro: 3.2 Mt/a heavy oil direct conversion capacity
• Hydrocracking Unit (HCU): 2 Mt//a
• Continuous Reforming Unit (CCRU): 2.4 Mt/a
• Polypropylene units: 2x450,000 t/a (largest domestic technology series)
• Supporting utility and auxiliary systems

The RTC (DCC-Pro) 3.2 million tonnes/year catalytic cracking plant is the core unit of the expansion commissioned in Aug 2025 | Credit: sohu.com

Processing Units Configuration

The refinery operates 18 major processing units following the 2025 expansion. Key processing capacities include: 

• Atmospheric and vacuum distillation units: 12 Mt/y (legacy 8 Mt/a ADU + new 6 Mt/a / 120,000 bpd ADU, unclear about actual number and capacity of the ADUs)
• DCC (from 2016): 2.2 Mt/a
• New FCC: 3.2 Mt/a
• HCU: 2 Mt/a
• CCR: 2.4 Mt/a.
• Aromatic Complex: 1.6 Mt/a
• PP Plants: 1.2 Mt/a (2x 450,000 t/y from 2025 in addition to 300,000 t/y legacy plant from 2018)  

The facility utilizes domestically developed heavy oil direct conversion technology with 100% domestic technology adoption rate, enabling production of 1.8 million tons per year total olefins and 1.2 million tons per year polymer-grade ethylene and propylene.

Feedstock and Products

The refinery processes heavy offshore crude oils with enhanced capability for high TAN (Total Acid Number) crudes. Annual crude import quota allocation is 3 million tons (60,000 bpd) for 2025. Primary products include transportation fuels (gasoline, diesel, kerosene, LPG), specialty asphalt, and petrochemicals. Chemical products comprise 1.2 million tons per year total polypropylene capacity in various grades (homopolymers, random copolymers, impact copolymers), 1.6 million tons per year aromatics (benzene, toluene, xylenes), and polymer-grade olefins for downstream applications.​

Strategic Relevance

The Daxie Refinery serves as CNOOC's second-largest refinery and represents China's largest heavy oil direct conversion facility for polymer-grade olefins production. The facility supports China's strategic objectives for enhanced self-sufficiency in high-end chemical materials while reducing energy consumption by 30% and carbon dioxide emissions by 200,000 tons annually compared to traditional processes. Located within the Ningbo-Zhoushan Port complex, the refinery benefits from superior logistics for crude imports and product distribution, contributing to the development of China's world-class petrochemical industry base in the Yangtze River Delta region. The facility's evolution from a simple asphalt producer to a sophisticated integrated complex demonstrates China's advancement in petrochemical technology development and industrial capability.

References

1. Ningbo Work Safety Association. CNOOC Ningbo Daxie Petrochemical Co, Ltd.
2. Chemical Talent Network. CNOOC Ningbo Daxie Petrochemical Co, Ltd.
3. Argus Media. Oct 28, 2015. CNOOC Ningbo makes progress on DCC start-up.
4. SmartChem. Feb 18, 2016. 20 billion yuan major series petrochemical projects commence production and construction in Ningbo.
5. Reuters. Jul 4, 2016. China's CNOOC completes $2 bln upgrade at coastal refinery.
6. The China Energy News. July 4, 2016. 13^th Edition. CNOOC Daxie Petrochemical Distillate Comprehensive Project was put into operation.
7. Wang Lu. Jul 7, 2016. CNOOC Daxie petrochemical distillate comprehensive utilization project is put into operation. People's Daily Online
8. McDermott. Apri 3, 2018.  Press Release: CB&I Announces Novolen Technology Award in China.
9. Zhejiang Renxin Academy of Environmental Sciences Co, Ltd. Aug 24, 2021. CNOOC Ningbo Daxie Petrochemical Co., Ltd. Distillate Oil Renovation and Expansion Project (Phase I: 500,000 tons/year hydrocarbon aromatization device) Completion Environmental Protection Acceptance Announcement.
10. Soliao. Sep 02, 2022. Daxie Petrochemical's 300,000 tons/year polypropylene unit has been put into operation.
11. Jigong Vogel Industrial Online. Oct 18, 2022. Localized design and manufacturing, the country's first set of Lums process polypropylene polymerization reactor was put into operation.
12. Shandong Well Data Co., Ltd. Sep 15, 2023. CNOOC Ningbo Daxie/Zhoushan Petrochemical Co., Ltd Case sharing.
13. Shanxi Carbon and New Materials Information Consulting Co, Ltd. Nov 5, 2024. The 14 units of the Daxie Petrochemical, Refining and Chemical Integration Public Works Project were successfully handed over!
14. Daisy Xu. Dec 27, 2024. Chinese qualified refineries win about 3.82 mil b/d crude import quota for 2025. S&P Global.
15. Reuters. Mar 4, 2025. China's CNOOC to launch refinery expansion after $2.7 bln upgrade, sources say.
16. energy, oil & gas magazine. Mar 6, 2025. $2.7 Billion Investment Propels CNOOC’s Daxie Refinery to New Heights​.
17. Refining, Chemical and Petrochemical Downstream Industry Network. Aug 14, 2025. CNOOC’s integrated refining and petrochemical Project Phase VI may be launched.
18. Hydrocarbon Processing. Aug 22, 2025. CNOOC completes construction on $2.9-B, 1.8-MMtpy integrated complex in east China.
19. Zheng Xin. Aug 22, 2025. China's largest petrochemical industry base, the 10-million-ton refining and chemical integration project, has been fully completed. China Daily.
20. Little Bear Technology Information. Aug 23, 2025. The Daxie Petrochemical Refining and Chemical Project has been fully completed, and the heavy oil conversion process has been 100% localized.
21. Sinopec Ningbo Engineering Co., Ltd. Aug 27, 2025. Daxie Petrochemical's polypropylene plant produces the first batch of qualified products.
22. Yuan Ting. Sep 2, 2025. CNOOC’s Launches Major Refining, Petrochemical Complex in East China. State-owned Assets Supervision and Administration Commission of the State Council.
23. Sohu. Sep 18, 2025. CNOOC's Daxie Petrochemical 10-Million-Tonne Integrated Refining and Petrochemical Project Successfully Commences Operations.