A system for producing phenol and bisphenol A comprising: a first production unit for producing phenol comprising a decomposition reaction unit and a purification unit; a second production unit for producing bisphenol A comprising a reaction unit and a concentration unit; and a removal unit for removing methanol and acetone during the production of phenol and bisphenol A. The removal unit includes a removal column comprising an overhead purge part, a bottom recirculation part and a supply part. The supply part comprises a purification unit discharge part to supply methanol, acetone, and water discharged from the purification unit to the removal column and a concentration unit discharge part to supply phenol, acetone, and water discharged from the concentration unit to the removal column, and is provided to the midsection of the removal column.

A system for producing phenol and bisphenol A comprising: a first production unit for producing phenol comprising a decomposition reaction unit and a purification unit; a second production unit for producing bisphenol A comprising a reaction unit and a concentration unit; and a removal unit for removing methanol and acetone during the production of phenol and bisphenol A. The removal unit includes a removal column comprising an overhead purge part, a bottom recirculation part and a supply part. The supply part comprises a purification unit discharge part to supply methanol, acetone, and water discharged from the purification unit to the removal column and a concentration unit discharge part to supply phenol, acetone, and water discharged from the concentration unit to the removal column, and is provided to the midsection of the removal column.

The present invention provides a polyhydric phenol compound which has an excellent alkali resistance and which does not cause a deterioration in color even when used as a resin raw material or a color developer. The polyhydric phenol compound includes: a bisphenol compound (A) represented by the following Formula (1) and a trisphenol compound (B) represented by the following Formula (2):

##STR00001## [wherein R.sup.1 represents a monovalent aliphatic hydrocarbon group having from 6 to 24 carbon atoms; each of R.sup.2, R.sup.3, R.sup.4, R.sup.5 and R.sup.6 represents a monovalent hydrocarbon group having from 1 to 15 carbon atoms; and each of a, b, c, d and e represents an integer from 0 to 4]; wherein the trisphenol compound (B) is contained in an amount, in terms of absorption intensity ratio at 254 nm, of less than 1.6% by area with respect to the amount of the bisphenol compound (A).

The present invention provides a polyhydric phenol compound which has an excellent alkali resistance and which does not cause a deterioration in color even when used as a resin raw material or a color developer. The polyhydric phenol compound includes: a bisphenol compound (A) represented by the following Formula (1) and a trisphenol compound (B) represented by the following Formula (2):

##STR00001## [wherein R.sup.1 represents a monovalent aliphatic hydrocarbon group having from 6 to 24 carbon atoms; each of R.sup.2, R.sup.3, R.sup.4, R.sup.5 and R.sup.6 represents a monovalent hydrocarbon group having from 1 to 15 carbon atoms; and each of a, b, c, d and e represents an integer from 0 to 4]; wherein the trisphenol compound (B) is contained in an amount, in terms of absorption intensity ratio at 254 nm, of less than 1.6% by area with respect to the amount of the bisphenol compound (A).

The present invention discloses a process for depolymerization of lignin to yield substituted phenolic monomers using Brnsted ionic liquid as catalyst under mild reaction conditions to obtain an overall yield of monomers up to 97%.

The present invention discloses a process for depolymerization of lignin to yield substituted phenolic monomers using Brnsted ionic liquid as catalyst under mild reaction conditions to obtain an overall yield of monomers up to 97%.