The California Air Resources Board (CARB) has issued an executive order authorising STAX Engineering to extend its barge-based emissions capture technology to tanker vessels at berth. This is the first time such a system has been approved for use on tankers, which make up a significant proportion of California’s maritime trade and are unable to use shore power due to safety concerns.
The new authorisation enables STAX to help operators comply with California’s Ocean-Going Vessels At-Berth Regulation, which came into effect for tankers at the ports of Los Angeles and Long Beach on 1 January 2025. The regulation will be applied across all Californian ports by 2027.
Tankers transporting crude oil, chemicals and LNG have been unable to use shore power due to safety risks associated with their volatile cargo. STAX’s barge-based system connects directly to a vessel’s auxiliary engine exhaust without requiring modifications or access to portside electrical infrastructure. It removes up to 99% of particulate matter and 95% of nitrogen oxides (NOx).
Mike Walker, CEO of STAX Engineering, said the technology ‘fills a long-standing gap by providing a safe, scalable solution that enables global tanker operators to comply with evolving emissions standards while significantly improving port air quality. Tankers are the backbone of global energy infrastructure—with over 1.3 million barrels of crude oil alone arriving just in California ports daily—yet they’ve lacked a safe, practical solution for meeting rising emissions standards. Our technology fills that gap. It helps operators comply with regulations while improving air quality for surrounding communities.’
The system is already in use at five Californian ports. Since early 2024, STAX has treated 1,192 vessels and recorded over 25,000 service hours, capturing 190 tonnes of pollutants. Tankers accounted for approximately 1,000 of those hours. The company has service agreements in place with Olympus Terminals in Long Beach, Shell’s Mormon Island Terminal in Los Angeles and MOL Chemical Tankers.
STAX aims to operate 27 barges by 2027 to meet expected demand. It has raised US$70 million to support this expansion and currently operates four authorised barges for the tanker segment.
Vincent Godfrey, CEO of Olympus Terminals, said: ‘Safety and operational reliability are non-negotiable in our industry, and STAX delivers on both fronts. Given the complexities of tanker operations, we need a partner who can integrate seamlessly and safely into our customers’ port calls without disrupting operations. STAX provides exactly that; a practical solution without requiring retrofits that allows us to meet our environmental responsibilities immediately, rather than waiting for future technologies.’
The company is also expanding into the UK market. It has secured £1.1 million through the Clean Maritime Demonstration Competition to support its role in PortZero, a decarbonisation project involving Seabound, Associated British Ports and Lomar Shipping. STAX will present its technology at London International Shipping Week in September.
