Multi-purpose catalytic distillation column and eterification process using same

A process for the treatment of a light cracked naphtha stream comprising isoamylene comprising the steps of:

• (a) feeding said light cracked naphtha stream to a distillation column reactor having a stripping section and two distillation reaction zones in series;
• (b) concurrently feeding a stream containing hydrogen to said distillation column reactor;
• (c) separating a C.sub.6 and heavier boiling fraction from said light cracked naphtha in said stripping section while boiling a C.sub.5 boiling fraction containing mercaptan and diolefin contaminants up into a first distillation reaction zone;
• (d) concurrently in said distillation reaction zone
• (i) reacting said mercaptans contained within said C.sub.5 boiling fraction with a portion of said diolefins contained within said C.sub.5 boiling fraction to produce sulfides having a boiling range higher than said C.sub.5 boiling fraction;
• (ii) reacting the remainder of said diolefins and any acetylenes contained within said C.sub.5 boiling fraction with a portion of said hydrogen to reduce the unsaturation of said diolefins and said acetylenes;
• and
• (iii) separating said C.sub.5 boiling fraction from said sulfides by fractional distillation;
• (e) feeding a stream containing methanol to said distillation column reactor to form a methanol/C.sub.5 azeotrope in said first distillation reaction zone, said azeotrope having a lower boiling point than said C.sub.5 boiling fraction;
• (f) boiling said azeotrope up into a second distillation reaction zone wherein a portion of the isoamylenes contained within said azeotrope react with a portion of the methanol contained within said azeotrope to form tertiary amyl methyl ether;
• (g) removing said tertiary amyl methyl ether, said C.sub.6 and heavier boiling fraction and said sulfides from said distillation column reactor as bottoms.