Innovation in maritime: HD HHI to begin LNG boil-off gas recycling demonstration

March 11, 2025, by Naida Hakirevic Prevljak

South Korean shipbuilder HD Hyundai Heavy Industries (HD HHI) has embarked on a project to demonstrate how to recycle evaporated gas emitted into the atmosphere during the construction of liquefied natural gas-powered ships into city gas.

HD HHI plans to conduct a demonstration project in April 2025 to recover the boil-off gas from a 7,900 TEU LNG-fueled containership currently under construction and use it as an energy source at its worksites.

During the commissioning phase of ships using LNG as fuel, the charged LNG naturally vaporizes and evaporates in the fuel tank. The evaporated gas causes the pressure in the fuel tank to increase.

While ships in operation can recover the evaporated gas and use it as fuel, ships under construction require periodic venting to the atmosphere to manage the pressure in the fuel tank.

Evaporated gas is methane, one of the major greenhouse gases, and to reduce greenhouse gas emissions, HD Korea Shipbuilding & Offshore Engineering (HD KSOE) and HD Hyundai Heavy Industries established a plan to reduce greenhouse gas emissions during the construction of LNG-fueled ships as a national task of the South Korean Ministry of Trade, Industry and Energy (MOTIE) in 2023.

HD KSOE devised the concept of recycling LNG-powered ships’ evaporated gas into onshore city gas and HD HHI put this concept into practice, creating an environment where evaporated gas emitted from ships under construction can be recovered and used for self-consumption as city gas within the workplace.

However, due to the lack of relevant laws and standards for the self-consumption of evaporated gas in Korea’s City Gas Business Act, HD HHI applied for a regulatory sandbox demonstration exemption from MOTIE to carry out this project, and received conditional approval on October 23, 2024.

The demonstration period lasts from March 31, 2025, to March 30, 2027.

HD HHI has since derived the ‘Demonstration Special Case Safety Standards’ in consultation with the Korea Gas Safety Corporation, a domestic city gas inspection agency, to ensure stability proceeding with the demonstration special case (January 21, 2025, subject to regulatory special case approval condition), and has fulfilled the conditions for the start of the demonstration special case by purchasing a new gas accident liability insurance policy to compensate for human and material damages that may occur.