Fluidized bed reactors for the catalytic CO₂ methanation is a promising concept within the power‐to‐gas (methane) process. Due to the intermittency of renewable electricity generation and thus hydrogen production, the subsequent methanation reactor should also be able to operate at lower feed flow rates, while maintaining fluidized bed conditions. Bubbling fluidized bed reactors offer the required flexibility as shown with the new type of working diagrams. These working diagrams visualize a decision window for (a) determining the reactor diameter and (b) operating the fluidized bed reactor with a turndown ratio of 0.5‐1.1. Reducing the turndown ratio (ie, inlet flow rate) could lead to defluidization, thus increasing temperature or reducing the pressure are alternatives to maintain fluidization conditions. The former method is not desired, as a temperature increase would significantly reduce the CH₄ yield due to thermodynamic constraints and therefore reduce the overall efficiency. An industrial CO₂ methanation reactor, for example, that is designed for 10 bara (1 bara = 100 kPa) and 340°C with a total inlet flow rate of 5000 m³_N · h⁻¹ (H₂/CO₂ = 4) can be operated at a turndown ratio of 0.5 (2500 m³_N · h⁻¹) at the same temperature and the same u₀/u_mf ratio by reducing the pressure to 5 bara with only a slight decrease in the CO₂ equilibrium conversion from 96.7% to 94.6%.

中文翻译：

---

识别鼓泡流化床反应器用于CO2甲烷化的工作图

用于催化CO _2的流化床反应器甲烷化在电力制气（甲烷）工艺中是一个很有前途的概念。由于可再生发电的间歇性以及由此产生的氢气，后续的甲烷化反应器还应该能够以较低的进料流速运行，同时保持流化床条件。鼓泡流化床反应器提供了所需的灵活性，如新型工作图所示。这些工作图显示了一个决策窗口，用于（a）确定反应器直径和（b）以0.5-1.1的调节比运行流化床反应器。降低调节比（即进口流量）可能会导致脱液，因此提高温度或降低压力是维持流态化条件的替代选择。不需要前一种方法，由于热力学约束，₄收率降低了整体效率。例如，工业CO ₂甲烷化反应器设计用于10 bara（1 bara = 100 kPa）和340°C，总入口流量为5000 m ³ _N ·h ^-1（H ₂ / CO ₂ = 4 ）可以通过将压力降低至5 bara，而CO ₂平衡仅略微降低，在相同的温度和相同的u ₀ / u _mf比率下以0.5的调节比（2500 m ³ _N ·h ^-1）进行操作从96.7％转换为94.6％。