Long Son Petrochemicals, a subsidiary of Thailand’s SCG Chemicals (SCGC), has restarted its Long Son petrochemical complex in southern Vietnam after roughly a 10-month shutdown, effective August 20, according to local media outlet The Investor and others. The Long Son complex, Vietnam’s first integrated petrochemical complex, is reported to have resumed operations as improved margins made the restart economically viable.
The Long Son petrochemical complex is an integrated facility producing olefins and polyolefins via naphtha cracking, with reported annual capacity of 1.35 million tonnes of olefins and a combined 1.4 million tonnes across three polyolefin plants. SCGC is reportedly also pursuing, alongside the restart, an expansion project (LSPE) to convert feedstock from naphtha to ethane.
Total investment is reported at approximately $5.4 billion, with annual olefin capacity of 1.35 million tonnes and combined polyolefin capacity of 1.4 million tonnes across three plants. The shutdown lasted approximately 10 months, with the restart confirmed on August 20, 2026. The feedstock-conversion expansion project (LSPE) is reported to carry an investment of approximately $500 million.
The Long Son complex reportedly struggled with profitability in its early operating period amid low oil prices and thin spreads, leading to a prolonged shutdown. The restart is said to reflect improved market conditions alongside SCGC’s efforts to normalize its integrated petrochemical business in Vietnam.
The shutdown and restart of a major Southeast Asian petrochemical complex illustrates how utilization rates in the region can swing sensitively with petrochemical spreads and supply-demand conditions. This can also serve as a reference point for investment decisions on new and expansion projects across the region.
Key points to watch include whether stable utilization rates are maintained following the restart and the progress of the naphtha-to-ethane conversion expansion project (LSPE).