Pursuing methanation as a means to recycle CO2

By the end of fiscal 2019, commissioning and continuous operation will begin on a new methanation plant that will produce 8 Nm³/h of methane from CO₂ and H₂. The test facility, located at the Koshijihara Plant of Inpex’s Nagaoka Field Office in Nagaoka City, Niigata Prefecture, is part of an industry-government collaboration led by the New Energy and Industrial Technology Development Organization (NEDO; Kawasaki City, Japan; www.nedo.go.jp), with partners Inpex Corp. (Tokyo; www.inpex.co.jp) and Hitachi Zosen Corp. (both Tokyo; www.hitachizosen.co.jp).

In the project (diagram), the partners aim to use this test facility to further develop methanation technology, which is one method for recycling CO₂. For feedstock, the plant will use CO₂ recovered from natural-gas processing at the Koshijihara Plant, and H₂ generated from water electrolysis using renewable electricity. The product methane is said to have a great potential as an energy carrier, and offers significant benefits because existing infrastructure for natural gas can be employed directly.

Through later full-scale operation, the partners aim to evaluate and examine technical issues, including how to optimize the methane synthesis process by varying a range of parameters, including reaction temperature, reaction pressure and reaction loads, and to develop methanation technology. For methane synthesis, the test facility uses a Hitachi Zosen plate reactor that achieves highly efficient heat recovery. As the world’s first trial using actual CO₂ in a plate reactor, this initiative is focused on the use of larger facilities in the future.