Conversion of oxgenates in purge from raw methanol evaporator

Abstract

The invention relates to a processes comprising the steps of: in an evaporator forming a gas phase methanol rich stream from a feed stream; withdrawing a liquid purge stream from the evaporator, said liquid purge stream comprising oxygenates and water; providing the gas phase methanol rich stream to a conversion step; and adding at least part of said liquid purge stream upstream the conversion step.

1 . A processes comprising the steps of:
 in an evaporator forming a gas phase methanol rich stream from a feed stream,   withdrawing a liquid purge stream from the evaporator, said liquid purge stream comprising oxygenates and water,   providing the gas phase methanol rich stream to a conversion step, and   adding at least part of said liquid purge stream upstream the conversion step.   
     
     
         2 . A process according to  claim 1 , wherein the conversion step is a gasoline conversion step. 
     
     
         3 . A process according to  claim 1 , wherein the feed stream comprises raw methanol. 
     
     
         4 . A process according to  claim 1 , wherein the oxygenates comprises ketones, aldehydes and/or higher alcohols. 
     
     
         5 . A process according to  claim 1 , wherein the liquid purge stream is added to a recycle stream from the conversion step. 
     
     
         6 . A process according to  claim 1 , wherein the liquid purge stream is added to the recycle stream from the conversion step up- and/or downstream a point where the gas phase methanol rich stream is added to the recycle stream from the conversion step. 
     
     
         7 . A process according to  claim 1 , wherein the liquid purge stream is added to the recycle stream from the conversion step by quenching. 
     
     
         8 . A plant comprising an evaporator or boiler, a conversion loop, at least one methanol mixing point and at least one purge mixing point. 
     
     
         9 . A plant according to  claim 8  wherein the conversion loop comprises a conversion step, a separator and means for returning a recycle stream to the conversion step. 
     
     
         10 . Plant according to  claim 8  wherein the conversion loop further comprises one or more heaters for heating the recycle stream, one or more coolers and condensers for condensing the converter effluent. 
     
     
         11 . Plant according to  claim 8 , wherein one or more purge mixing points are arranged up-steam and/or downstream the methanol mixing point. 
     
     
         12 . A plant comprising an evaporator or boiler, a conversion loop, at least one methanol mixing point and at least one purge mixing point, arranged to carry out the process according to  claim 1 . 
     
     
         13 . Gasoline product produced according to the process of  claim 1 . 
     
     
         14 . Gasoline product produced by the plant of  claim 8 .