Method and apparatus for decomposing phenolic by-product

An apparatus for decomposing a phenolic by-product generated in a bisphenol A preparation process, the apparatus comprising:

• a multistage reactive distillation column separating the phenolic by-product into an upper discharge stream containing an active component, a side discharge stream containing acetophenone, and a bottom discharge stream containing tar;
• and
• a moving line system including a side discharge stream moving line through which the side discharge stream is discharged and moved, and a bottom discharge stream moving line through which the bottom discharge stream is discharged and moved,
• wherein the side discharge stream moving line and the bottom discharge stream moving line are connected to each other so that the side discharge stream and the bottom discharge stream are joined with each other to form a mixed discharge stream.