Synthesis of Drop-in Liquid Fuels and Chemicals from Methanol, Ethanol or Syngas Using Mixed Catalysts

Abstract

The present invention discloses a system for converting synthesis gas to liquid hydrocarbons with comparable energy content to gasoline within mixed catalyst bed single reactor or double reactor systems. Varying catalyst composition and temperature profiles allow for significant tailoring of reaction conditions to the specific feedstocks or the desired products.

What is claimed is: 
     
         1 ) A method of synthesizing gasoline boiling range hydrocarbons catalytically from a syngas mixture using a single reactor containing a homogenous mixture of a methanol synthesis catalyst, a methanol to dimethyl ether synthesis catalyst and a dimethyl ether to hydrocarbon synthesis catalyst where:
 a) The methanol synthesis catalyst is a single metal or metal oxide, or a combination such as Cu—ZnO.   b) The methanol to dimethyl ether synthesis catalyst is a methanol dehydration catalyst such as gamma-alumina.   c) The hydrocarbon synthesis catalyst is a zeolite material such as ZSM-5.   
     
     
         2 ) The method of  claim 1  where the zeolite catalyst is doped with a transition metal element in the range of 1-10 wt %. 
     
     
         3 ) The method of  claim 2  where the zeolite catalyst is doped with zinc. 
     
     
         4 ) The method of  claim 1  where the temperature within the reactor is varied linearly with a cooler inlet and warmer outlet. 
     
     
         5 ) The method of  claim 1  where the pressure inside the reactor is controlled in the range of atmospheric pressure to 500 psi. 
     
     
         6 ) The method of  claim 1  where the catalyst is comprised of two or more mixed zones where the initial catalyst has a larger portion of methanol synthesis catalyst and the subsequent zones have larger portions of hydrocarbon synthesis catalyst. 
     
     
         7 ) The method of  claim 1  where the H 2 /CO ratio of the feed gas is varied from 1/1 to 2/1. 
     
     
         8 ) The method of  claim 1  where the syngas contains a significant amount of N 2 . 
     
     
         9 ) The method of  claim 1  where the syngas is produced using air as an oxidant. 
     
     
         10 ) The method of  claim 1  where a second reactor filled with a zeolite catalyst is used after the first reactor to further convert lower molecular weight hydrocarbons. 
     
     
         11 ) The method of  claim 10  where the first reactor is operated at a higher pressure, approximately 200-500 psi, while the second reactor is operated at atmospheric pressure. 
     
     
         12 ) The method of  claim 1  where the reactor is configured as portable system for transport and deployment to locations where feedstocks are abundant for synthesis gas. 
     
     
         13 ) A method of synthesizing gasoline boiling range hydrocarbons catalytically from a syngas mixture using two reactors comprising the steps of:
 a) Reacting H 2 /CO in the first reactor containing a homogenous mixture of a methanol synthesis catalyst and a methanol to dimethyl ether synthesis catalyst to form dimethyl ether, and,   b) Reacting dimethyl ether in the second reactor containing a dimethyl ether to hydrocarbon synthesis catalyst to form the gasoline boiling range hydrocarbon product.   
     
     
         14 ) The method of  claim 13  where the methanol synthesis catalyst is a metal or metal oxide, or combination such as Cu—ZnO. 
     
     
         15 ) The method of  claim 13  where the methanol to dimethyl ether synthesis catalyst is a methanol dehydration catalyst such as gamma-alumina. 
     
     
         16 ) The method of  claim 13  where the hydrocarbon synthesis catalyst is a zeolite material such as ZSM-5. 
     
     
         17 ) The method of  claim 16  where the zeolite catalyst is doped with a transition metal element in the range of 1-10 wt %. 
     
     
         18 ) The method of  claim 13  where the zeolite catalyst is doped with zinc. 
     
     
         19 ) The method of  claim 13  where the temperature within the first reactor is varied in the reactor with a cooler inlet and warmer outlet. 
     
     
         20 ) The method of  claim 13  where the pressure inside the reactors is controlled in the range of atmospheric pressure to 500 psi. 
     
     
         21 ) The method of  claim 13  where the catalyst in the first reactor is comprises of two or more mixed zones where the initial catalyst has a larger portion of methanol synthesis catalyst and the subsequent zones have larger portions of methanol dehydration catalyst. 
     
     
         22 ) The method of  claim 13  where the H 2 /CO ratio of the feed gas is varied from 1/1 to 2/1. 
     
     
         23 ) The method of  claim 13  where the syngas contains a significant amount of N 2 . 
     
     
         24 ) A method of  claim 13  where the syngas is produced using air as an oxidant. 
     
     
         25 ) The method of  claim 13  where the first reactor is operated at higher pressure, approximately 200-500 psi, while the second reactor is operated at atmospheric pressure. 
     
     
         26 ) The method of  claim 13  where the reactor is configured as portable system for transport and deployment to locations where feedstocks are abundant for synthesis gas.