Kawasaki Heavy Industries Unveils Hydrogen Co-Firing Gas Engine

Kawasaki Heavy Industries (KHI) announced the world’s first commercial launch of a 30% hydrogen co-firing large-scale gas engine. Since October 2024, KHI has been conducting operational verification at Kobe Works, testing an 8-MW gas engine power generation system that can co-fire natural gas mixed with up to 30% hydrogen as fuel. The verification, completed in September 2025, focused on hydrogen supply, maintainability, and other operational factors.

Product features include:

• High Efficiency & Low NOx Design: Achieves both high efficiency and environmentally friendly performance.
• Flexible Operation: The hydrogen co-firing ratio can be adjusted at all times, even during operation.
• Safety Measures: Equipped with hydrogen leak detectors, nitrogen purge systems, and additional safety features.
• Retrofit Compatibility: Existing engines can be retrofitted to hydrogen co-firing designs.

Since 2011, KHI’s Kawasaki Green Gas Engine obtained over 240 orders as a high-efficiency gas engine burning natural gas in the 5 – 8 MW power range. Leveraging this technology and experience, the hydrogen-ready model can also burn city gas to satisfy decarbonization and energy transition initiatives. The transitionary product allows practical and sustainable decarbonization as a distributed power source by raising the hydrogen utilization ratio, all the while leveraging existing facilities and infrastructure.

New hydrogen-capable gas engine | Image Credit: KHI

In preparation for the widespread adoption of hydrogen energy, KHI is establishing a hydrogen supply chain which includes production, transportation, storage, and utilization. The company will proceed with actively developing hydrogen or hydrogen-related technologies to satisfy this supply chain and the global carbon-neutral society.

Hydrogen Emissions

In August, the Kansai Electric Power Co., BIPROGY, and Kawasaki announced demonstration tests to calculate and record CO₂ emissions during hydrogen processes, from production to power supply, in a hydrogen co-firing application. The environmental attribute management tests will occur at the Himeji No. 2 Power Station, with goals to improve the value of low-carbon hydrogen and expand its usage.

It will deploy nuclear-derived low-carbon hydrogen from the Fukui Prefecture and renewably generated green hydrogen from the Yamanashi Prefecture. Testing will calculate and track the CO₂ emissions of hydrogen every 30 minutes, verifying whether the power derived from hydrogen co-firing can be attributed to low-carbon hydrogen or green hydrogen. Det Norske Veritas will ensure that the tracking method is compliant with international standards.

Through these demonstration tests, the partners aim to determine electricity origin and the time/location of hydrogen production for consumers. It will also build Japan’s hydrogen supply chain; help achieve carbon neutrality and encourage the joint investigation of commercialization.

KM Comp-H2

In late March 2025, KHI started building a hydrogen compressor demonstration facility at its Harima Works in Hyogo Prefecture, Japan. The facility will test the company’s new, world-first centrifugal hydrogen compressor for hydrogen liquefaction plants, the KM Comp-H₂. KHI expects to complete construction in November 2025, followed by one year of operational testing.

The new machine achieves high-boosting performance through ultra-high-speed rotating technology, including KHI’s newly developed impeller, which optimizes a small molecular weight gas like hydrogen. Its centrifugal design handles high flow rates and reduces the installation footprint by approximately 86% compared to current hydrogen compressors.