Methanol-gas saturator for catalytic conversion system

Abstract

A process for introducing a exothermic reactant vapor stream to an adiabatic catalyst zone comprising the steps of: preheating a volatile liquid exothermic reactant stream below its autogenous temperature under process pressure; contacting the preheated liquid reactant stream in a saturator unit with a hot diluent gas to vaporize the reactant stream in gaseous mixture with the diluent stream; directing the gaseous mixture from the saturator unit to the catalyst zone for exothermic conversion of the reactant under substantially adiabatic reaction conditions in the presence of diluent gas; recovering reaction products and diluent gas from the catalyst zone; separating diluent gas from the products, compressing and recycling the diluent gas to the saturator unit. Methods and apparatus are provided for use in a continuous catalytic MTG process for making gasoline boiling range hydrocarbons exothermically from a methanol-containing reactant stream diluted with a methane-rich recycle gas stream by contacting the diluted feedstock with a fixed bed of crystalline aluminosilicate zeolite catalyst in an adiabatic reaction zone at elevated temperature and pressure. The recycle gas may be contacted with the liquid feedstock in a counter-current vertical tower operatively connected through an upper gas outlet to the reaction zone and wherein liquid feedstock flows downwardly under gravity through a saturation zone.