Reactor system for producing gaseous products

Abstract

Reactor systems are provided for the catalytic conversion of liquid feedstocks to synthesis gases and other noncondensable gaseous products. The reactor systems include a heat exchange reactor configured to allow the liquid feedstock and gas product to flow concurrently in a downflow direction. The reactor systems are particularly useful for producing hydrogen and light hydrocarbons from biomass-derived oxygenated hydrocarbons using aqueous phase reforming. The generated gases may find used as a fuel source for energy generation via PEM fuel cells, solid-oxide fuel cells, internal combustion engines, or gas turbine gensets, or used in other chemical processes to produce additional products. The gaseous products may also be collected for later use or distribution.

1 . A concurrent downflow reactor for converting a liquid feedstock to a noncondensable gas product using a heterogeneous catalyst, the reactor comprising:
 a reaction chamber comprising at least one reaction tube containing a heterogenous catalyst therein;   an inlet having a pressure P i  and adapted to feed the liquid feedstock to an upper portion of the reaction chamber;   an outlet having a pressure P o  and adapted to discharge the noncondensable gas product and an effluent stream from a lower portion of the reaction chamber; and   wherein P i  is greater than P o .   
     
     
         2 . The reactor of  claim 1 , wherein the reaction chamber comprises a plurality of reaction tubes each containing a catalyst therein, an outer shell adapted to enclose at least a portion of the reaction tubes, and a heating system adapted to introduce a heating medium into the shell to provide heat to the reaction tubes. 
     
     
         3 . The reactor of  claim 1 , wherein the catalyst comprises at least one Group VIIIB metal and wherein the feedstock comprises water and at least one C 2+  water soluble oxygenated hydrocarbon. 
     
     
         4 . The reactor of  claim 3 , wherein the Group VIIIB metal is selected from the group consisting of platinum, nickel, palladium, ruthenium, rhodium, iridium, iron, alloys thereof, and mixtures thereof, and wherein the oxygenated hydrocarbon is a C 2-6  oxygenated hydrocarbon. 
     
     
         5 . The reactor of  claim 4 , the catalyst further comprising a second catalytic material selected from the group consisting of Group VIIIB metals, Group VIIB metals, Group VIB metals, Group VB metals, Group IVB metals, Group IIB metals, Group IB metals, Group IVA metals, Group VA metals, alloys thereof, and mixtures thereof. 
     
     
         6 . The reactor of  claim 5 , wherein the second catalytic material is rhenium and the Group VIIIB transition metal is selected from the group consisting of iron, nickel, palladium, platinum, ruthenium, rhodium, alloys thereof, and mixtures thereof. 
     
     
         7 . The reactor of  claim 3 , wherein the catalyst is adhered to a support constructed from one or more materials selected from the group consisting of carbon, silica, silica-alumina, alumina, zirconia, titania, ceria, vanadia and mixtures thereof. 
     
     
         8 . The reactor of  claim 1 , wherein the noncondensable gas product comprises one or more gases selected from the group consisting of hydrogen, carbon dioxide, carbon monoxide, methane, ethane, ethylene, propane, propylene, butane, butane, pentane and pentene. 
     
     
         9 . An energy generation system comprising any one of the reactors of  claim 1 - 8  and an energy generation device adapted to use the noncondensable gas product as a fuel. 
     
     
         10 . The energy generation system of  claim 9 , wherein the energy generation device is a member selected from the group consisting of an internal combustion engine, PEM fuel cell, solid-oxide fuel cell, and gas turbine genset. 
     
     
         11 . A method for the manufacture of noncondensable gas, the method comprising:
 reacting a liquid feedstock comprising water and at least one C 2+  water soluble oxygenated hydrocarbon using a heterogeneous catalyst comprising one or more Group VIIIB metals, at a temperature between about 80° C. to 300° C. and a reaction pressure suitable to produce the noncondensable gas and an effluent, wherein a pressure gradient provides concurrent downflow of the liquid feedstock, effluent and noncondensable gas.   
     
     
         12 . The method of  claim 11 , wherein the Group VIIIB metal is selected from the group consisting of platinum, nickel, palladium, ruthenium, rhodium, iridium, iron, alloys thereof, and mixtures thereof. 
     
     
         13 . The method of  claim 11 , wherein the catalyst further comprises a second catalytic material selected from the group consisting of Group VIIB metals, Group VIB metals, Group VB metals, Group IVB metals, Group IIB metals, Group IB metals, Group IVA metals, Group VA metals, alloys thereof, and mixtures thereof. 
     
     
         14 . The method of  claim 13  wherein the second catalytic material is rhenium and the Group VIIIB metal is selected from the group consisting of iron, nickel, palladium, platinum, ruthenium, rhodium, alloys thereof, and mixtures thereof. 
     
     
         15 . The method of  claim 11  wherein the catalyst is adhered to a support constructed from one or more materials selected from the group consisting of carbon, silica, silica-alumina, alumina, zirconia, titania, ceria, vanadia and mixtures thereof. 
     
     
         16 . The method of  claim 11 , wherein the oxygenated hydrocarbon is a C 1-6  oxygenated hydrocarbon. 
     
     
         17 . The method of  claim 16 , wherein the oxygenated hydrocarbon is a member selected from the group consisting of sugar and sugar alcohol. 
     
     
         18 . The method of  claim 11 , wherein the reaction temperature is between about 150° C. and about 270° C. and the reaction pressure is between about 72 psig and about 1300 psig. 
     
     
         19 . The method of  claim 11  using any one of the reactors of  claims 1 - 8 . 
     
     
         20 . The method of  claim 11 , wherein the noncondensable gas comprises one or more gases selected from the group consisting of hydrogen, carbon dioxide, carbon monoxide, methane, ethane, ethylene, propane, propylene, butane, butane, pentane and pentene. 
     
     
         21 . The method of  claim 11 , wherein the pressure gradient is in the range of 0.5-3 psig.