Key Takeaways
- AdvanSix entered a process design and licensing agreement with Stamicarbon to assess a DEF production expansion at its integrated Hopewell, Virginia site, which already produces all required DEF inputs: ammonia, carbon dioxide, and high-purity water.
- DEF is a mandatory emissions-reduction additive injected into diesel engine exhaust systems; demand is growing across transportation, construction, agriculture, and industrial equipment, while domestic U.S. supply remains limited.
- The proposed facility would use Stamicarbon's proprietary NX STAMI™ Urea technology and would be the first application in which all urea melt production is dedicated exclusively to DEF.
- A final investment decision is targeted for H1 2027, with a potential DEF plant startup in 2029; the project is expected to require a multi-year capital commitment.
- The expansion would complement AdvanSix's existing ammonium sulfate fertilizer operations at Hopewell, which the company said will continue at full capacity.
AdvanSix (NYSE: ASIX), a vertically integrated chemistry company, has signed a process design and licensing agreement with Stamicarbon — the nitrogen technology arm of Nextchem (MAIRE Group) — to evaluate expanding its ammonia platform at its Hopewell, Virginia facility to produce Diesel Exhaust Fluid (DEF). The agreement marks an early-stage step toward a potential new domestic manufacturing capability, with a final investment decision targeted for the first half of 2027 and a possible plant startup in 2029.
Why DEF and Why Hopewell
DEF is a mandatory additive for modern diesel engines, injected into the exhaust system to break down nitrogen oxide (NOx) emissions into harmless nitrogen and water. Regulatory requirements for NOx control are expanding across the transportation, construction, agriculture, and industrial sectors, driving sustained demand growth — particularly among Class 8 heavy trucks operating in the Mid-Atlantic and Northeast United States. Despite growing demand, domestic DEF supply remains constrained, with the market currently reliant on production from other regions and imports.
The Hopewell site already produces ammonia, carbon dioxide, and high-purity water — the three inputs required to manufacture DEF — making it a natural candidate for this type of expansion without requiring new upstream infrastructure.
“As a U.S. manufacturer, AdvanSix is uniquely situated to enable reliable, domestic supply to meet growing demand in a market currently served by production from other regions and imports. Our integrated ammonia platform provides us with the core capability to build a new, differentiated, high-value offering to meet market demands in the DEF value chain,” said Erin Kane, President and CEO of AdvanSix. “By exploring this expansion, we are creating future optionality to expand into adjacent products as market needs evolve while reinforcing our commitment to disciplined capital allocation and long-term value creation.”
AdvanSix's Technology Partnership with Stamicarbon
The project will use Stamicarbon's NX STAMI™ Urea technology, which will feed a dedicated DEF production unit designed to convert the entire urea melt output into DEF. Stamicarbon and its parent Nextchem describe this as a first-of-its-kind configuration — the first project in which all urea melt from a Stamicarbon-licensed plant may be directed exclusively toward DEF rather than agricultural or industrial fertilizer applications.
“This award confirms the strength and versatility of our nitrogen technology portfolio, which is increasingly finding applications beyond traditional fertilizer utilizations,” said Fabio Fritelli, Managing Director of Nextchem. “By leveraging our proprietary NX STAMI™ Urea technology, we are proud to support the development of emission reduction solutions for the mobility sector such as DEF, while further strengthening Nextchem's presence in North America.”
Timeline and Next Steps For AdvanSix
The project will advance through detailed engineering and development phases before AdvanSix makes a final investment decision, which is targeted for the first half of 2027. If approved, the company anticipates a multi-year capital investment with a potential DEF plant startup in 2029. The company said it will provide additional updates as engineering, commercial, and financial milestones are reached and regulatory approvals are secured. AdvanSix added that the contemplated DEF expansion would not affect its existing ammonium sulfate fertilizer production at Hopewell, which serves the U.S. farming market.
