IHI Successfully Demonstrates Process Gas Compressor for Decarbonization

IHI Corp. and IHI Rotating Machinery Engineering (IRM) executed a successful demonstration test for a new process gas compressor using CO₂ as the working fluid, achieving a maximum discharge pressure of 20MPaG. The test deployed a turbo-type unit featuring a geared, multi-shaft, multi-stage configuration with multiple pinion shafts driven by an internal gear system.

A successful outcome enables the injection of supercritical CO₂ into deep geological formations, like deep saline aquifers, to advance commercial carbon capture, utilization, and storage (CCUS) and progress industrial decarbonization. Unlike single-shaft, multi-stage compressors where all impellers rotate at the same speed, the geared architecture enables stage-by-stage optimization of impeller speeds, improving energy efficiency and space efficiency.

With this milestone demonstration, IHI and IRM will expand the application of their compression technologies to processes with high decarbonization potential, establish core capabilities across the CCUS value chain, and further improve system reliability. The IHI Group will help reduce environmental impact and expand decarbonization-based infrastructure, contributing to a sustainable and low-carbon society.

IRM’s process gas compressor portfolio includes both centrifugal and reciprocating compressors, which are manufactured at its Yokohama Factory in Japan. IHI leverages high-speed, high-efficiency centrifugal technologies and cryogenic gas processing expertise to deliver performance and reliability across various industrial processes, including air separation units and LNG receiving terminals.

Liquid Ammonia Turbine

At the 2025 Cogeneration Award, IHI Corp. and IHI Power Systems received the Chairman’s Award in the Technology Development Category for a project titled: Development of the 2 MW-Class Gas Turbine Cogeneration System Fueled Exclusively by Liquid Ammonia. IHI’s project represented the world’s first successful development of a gas turbine using only liquid ammonia and demonstrated that the technology reached an adequate level for practical social implementation.

IHI, Tohoku University, and the National Institute of Advanced Industrial Science and Technology successfully developed and demonstrated CO₂-free power generation using a gas turbine fueled completely by liquid ammonia in 2022. This portion of IHI’s program fell under the Green Innovation Fund and the New Energy and Industrial Technology Development Organization.

Starting in July 2024, IHI executed long-term durability testing at its Aioi Works in Aioi City, Japan, attempting to validate social implementation. The testing confirmed that IHI’s system achieved the planned power output and sufficiently suppressed N₂O and NO_x emissions. It also demonstrated durability performance comparable to conventional natural gas operation.

Electricity generated during the testing phase was recirculated and used on-site at Aioi Works. Also, by firing low-carbon ammonia as fuel, the project provided decarbonization value and accelerated decarbonization initiatives for Expo 2025 in Osaka, Kansai. Building on these project results, IHI is also progressing efforts toward 100% ammonia combustion in large-scale gas turbines with GE Vernova.

Among decarbonized fuels, IHI is prioritizing green ammonia and working to establish the complete value chain—from production, storage, and transportation to utilization—to validate and advance social implementation.