Recently, ENN Natural Gas’s Technology Innovation Center successfully commissioned a pilot scale CO?-to-methane hydrogenation unit at its Shandong demonstration base. This milestone marks an important breakthrough in CO? utilization and provides a technical solution for scalable energy storage and renewable energy consumption.

The 50 Nm3/h pilot-scale unit achieves stable full load operation through automatic regulation of the hydrogen–carbon ratio and staged control of reactor temperatures. The product gas contains ≤300 ppm CO? and more than 97% methane, meeting the requirements of standards including Coal-based synthetic natural gas (GB/T 33445-2023), Natural Gas (GB 17820-2020), and quality requirements for gases entering long-distance transportation gas pipeline (GB/T 37124-2018).

Image: ENN NG’s independently developed 50 Nm3/h CO? methanation system

CO? methanation is a strongly exothermic reaction with inherent challenges: thermodynamics favor low temperatures for higher equilibrium conversion, while kinetics require high temperatures for faster reaction rates. To address this contradiction, ENN NG’s team developed a three stage methanation process with series parallel switching, consisting of a high temperature stage, a medium–high temperature stage, and a deep conversion stage. The first two stages overcome kinetic limitations and achieve high reaction rates, while interstage cooling and heat removal allow the final stage to operate at lower temperatures closer to thermodynamic equilibrium, thus ensuring high overall conversion efficiency.

CO? catalytic hydrogenation to methane is a promising carbon recycling technology with significant application potential in large scale renewable energy consumption and coupling with carbon capture, utilization, and storage (CCUS) systems to enable negative emissions. While commercial demonstration projects have already emerged overseas, domestic efforts remain on catalyst and process R&D. Leveraging its extensive expertise in coke oven gas methanation, ENN NG has integrated breakthroughs in catalysts and process design to develop a high efficiency, stable CO? hydrogenation-to-methane system with proprietary intellectual property. For countries with high natural gas import dependence, this technology offers a potential new pathway toward energy independence.

Looking ahead, the R&D team will adhere to the principles of “engineering” and “productization,” comprehensively addressing lifecycle engineering challenges such as industrial scale-up, energy efficiency, operational stability, and cost management. Through continuous technology iteration, ENN NG will further enhance this innovative solution and contribute to achieving China’s carbon peaking and carbon neutrality goals.