Table 1. Description of the Process Instruments in Methanation Furnace.

Tags	Descriptions
U1	Flow rate of process gas at MF’s exit
U2	Pressure of process gas at MF’s entrance
U3	Pressure of process gas into F3’s entrance
U4	Temperature of upper bed at MF
U5	Temperature of middle bed at MF
U6	Temperature of lower bed at MF
U7	Temperature of process gas at MF’s exit
U8	Temperature of process gas at MF’s exit
U9	Temperature of synthesis gas at F2’s exit
U10	Liquid level of F2
Y	Content of CO and CO2 at MF’s exit