Method for preparing synthesis gas

A method for preparing synthesis gas, the method comprising:

• supplying a cracked gas stream discharged from a cracking furnace of a naphtha cracking center (NCC) process to a gasoline fractionator;
• supplying a side discharge stream of the gasoline fractionator to a first stripper, operating the first stripper under conditions in which a first steam stream is supplied to the first stripper, and separating a pyrolysis gas oil (PGO) stream including a PGO from a lower portion of the first stripper;
• splitting a lower discharge stream from the gasoline fractionator into a reflux stream and a supply stream, supplying the supply stream to a second stripper, and operating the second stripper under conditions in which a second steam stream is supplied to the second stripper, and separating a pyrolysis fuel oil (PFO) stream including a PFO from a lower portion of the second stripper;
• and
• supplying a mixed oil stream of the PGO stream and the PFO stream to a combustion chamber for a gasification process to obtain synthesis gas,
• wherein the method satisfies the following Equations 1 and 2:
• G≥0.5,G=GS/GF [Equation 1]
• F≤0.035,F=FS/FF [Equation 2]
• wherein GF is a flow rate of the side discharge stream from the gasoline fractionator, GS is a flow rate of the first steam stream, FF is a flow rate of the supply stream, and FS is a flow rate of the second steam stream.