The invention discloses a
coal tar deep processing technology for directly extracting industrial
naphthalene by adding an alkali after normal- and reduced-pressure treatments. In the technology, coaltar is used as a
raw material, the alkali is directly added after normal- and reduced-pressure treatments, wherein a preliminary
distillation tower and a
distillation front
tower adopts negative-pressure operation, and other parts adopt normal-pressure operation. The technology is realized by the following process: crude
tar is dehydrated by a
dehydration tower and then enters the negative-pressure preliminary
distillation tower, separation is carried out by the negative-pressure preliminary distillation tower,
asphalt is produced at the bottom of the negative-pressure preliminary distillationtower and enters an
asphalt process through a tubular furnace, heavy oil is produced at the top of the negative-pressure preliminary distillation tower, preliminary distillation oil gas produced at the top of the negative-pressure preliminary distillation tower enters a distillation front tower, a
naphthalene oil fraction is collected at the bottom of the distillation front tower,
phenol oil is produced at the top of the distillation front tower, the
naphthalene oil fraction collected at the bottom of the distillation front tower enters a naphthalene tower for further separation, and naphthalene oil is produced at the top of the naphthalene tower. The invention has the advantages of good separation ability, low collection temperature of the preliminary distillation fraction, higher quality of the extracted
asphalt and the subsequent naphthalene washing oil, and the invention has the advantages of simple process
route, energy saving and
environmental protection, and high separation ability.