Staged catalyst loading for pyrolysis oil hydrodeoxygenation

Abstract

A method for deoxygenating a biomass-derived pyrolysis oil is described. The method includes combining a biomass-derived pyrolysis oil stream with a heated low-oxygen-py-oil diluent recycle stream to form a heated diluted py-oil feed stream that has a temperature of about 150° C. or greater. The heated diluted py-oil feed stream is contacted with a first deoxygenating catalyst in a first bed of a reactor to form a low-oxygen biomass-derived pyrolysis oil. The low-oxygen biomass-derived pyrolysis oil is contacted with a hydrocracking catalyst in a second bed of the reactor to form a hydrocracked low-oxygen biomass-derived pyrolysis oil effluent. A portion of the hydrocracked low-oxygen biomass-derived pyrolysis oil effluent comprises the heated low-oxygen biomass-derived py-oil diluent recycle stream.

1 . A method for deoxygenating biomass-derived pyrolysis oil comprising:
 combining a biomass-derived pyrolysis oil stream with a heated low-oxygen-py-oil diluent recycle stream to form a heated diluted py-oil feed stream that has a temperature of about 150° C. or greater;   contacting the heated diluted py-oil feed stream with a first deoxygenating catalyst in a first bed of a reactor in the presence of hydrogen at first hydroprocessing conditions effective to form a low-oxygen biomass-derived pyrolysis oil; and   contacting the low-oxygen biomass-derived pyrolysis oil with a hydrocracking catalyst in a second bed of the reactor in the presence of hydrogen at hydrocracking conditions effective to form a hydrocracked low-oxygen biomass-derived pyrolysis oil effluent;   wherein a portion of the hydrocracked low-oxygen biomass-derived pyrolysis oil effluent comprises the heated low-oxygen biomass-derived py-oil diluent recycle stream.   
     
     
         2 . The method of  claim 1  further comprising:
 introducing a hydrogen stream to the reactor between the first and second beds to adjust the ratio of hydrogen to hydrocarbon in the second bed and to adjust a temperature in the second bed. 
 
     
     
         3 . The method of  claim 1  wherein contacting the heated diluted py-oil feed stream comprises contacting the heated diluted py-oil feed stream with the first deoxygenating catalyst at the first hydroprocessing conditions that include a reaction temperature of from about 150° C. to about 400° C. 
     
     
         4 . The method of  claim 1  wherein contacting the low-oxygen biomass-derived pyrolysis oil comprises contacting the low-oxygen biomass-derived pyrolysis oil with the hydrocracking catalyst at the hydrocracking conditions that include a reaction temperature of from about 150° C. to about 500° C. 
     
     
         5 . The method of  claim 1  wherein contacting the heated diluted py-oil feed stream comprises partially deoxygenating the heated diluted py-oil feed stream to form the low-oxygen biomass-derived pyrolysis oil that comprises a hydroprocessed organic phase that has a residual oxygen content of from about 5 to about 25 wt % of the hydroprocessed organic phase. 
     
     
         6 . The method of  claim 1  wherein the heated low-oxygen-py-oil diluent recycle stream has a residual oxygen content of from about 10 to about 25 wt % of the hydroprocessed organic phase. 
     
     
         7 . The method of  claim 1  wherein the step of combining comprises forming the heated diluted py-oil feed stream at the feed temperature of from about 150° C. to about 400° C. 
     
     
         8 . The method of  claim 1  wherein the step of combining comprises introducing the heated low-oxygen-py-oil diluent recycle stream to the biomass-derived pyrolysis oil stream that has a temperature of from about 0° C. to about 100° C. 
     
     
         9 . The method of  claim 1  wherein the step of combining comprises introducing the heated low-oxygen-py-oil diluent recycle stream that has a temperature of from about 200° C. to about 450° C. to the biomass-derived pyrolysis oil stream. 
     
     
         10 . The method of  claim 1  wherein the step of combining comprises combining the biomass-derived pyrolysis oil stream with the heated low-oxygen-py-oil diluent recycle stream at a predetermined recycle ratio of from about 1:1 to about 10:1, wherein the predetermined recycle ratio is defined by a recycle mass flow rate of the heated low-oxygen-py-oil diluent recycle stream to a py-oil mass flow rate of the biomass-derived pyrolysis oil stream. 
     
     
         11 . The method of  claim 1  wherein the first hydroprocessing conditions or the hydrocracking conditions or both include a reactor pressure of about 2 to about 20 MPa (g). 
     
     
         12 . The method of  claim 1  wherein the first hydroprocessing conditions include a fresh feed weight hourly space velocity of the biomass-derived pyrolysis oil stream per volume of from about 0.1 hr −1  to about 2 hr −1 . 
     
     
         13 . The method of  claim 1  wherein contacting the heated diluted py-oil feed stream comprises contacting the heated diluted py-oil feed stream with the first deoxygenating catalyst by a residence time of about 60 sec or less, wherein the residence time is defined by a time from when the biomass-derived pyrolysis oil stream is combined with the heated low-oxygen-py-oil diluent recycle stream to when the heated diluted py-oil feed stream initially contacts the first deoxygenating catalyst. 
     
     
         14 . The method of  claim 1  further comprising:
 removing water from and separating the hydrocracked low-oxygen biomass-derived pyrolysis oil effluent to form a water-depleted low-oxygen py-oil recycle stream; and 
 heating at least a portion of the water-depleted low-oxygen py-oil recycle stream to form at last a portion of the heated low-oxygen py-oil diluent recycle stream. 
 
     
     
         15 . The method of  claim 1  further comprising:
 removing water from and separating the hydrocracked low-oxygen biomass-derived pyrolysis oil effluent to form a water-depleted low-oxygen py-oil intermediate stream; and 
 contacting the water-depleted low-oxygen py-oil intermediate stream with a second deoxygenating catalyst in the presence of hydrogen at second hydroprocessing conditions effective to form an ultralow-oxygen biomass-derived pyrolysis oil effluent. 
 
     
     
         16 . A method for deoxygenating a biomass-derived pyrolysis oil comprising:
 combining a biomass-derived pyrolysis oil stream with a heated low-oxygen-py-oil diluent recycle stream to form a heated diluted py-oil feed stream that has a temperature of about 150° C. or greater;   contacting the heated diluted py-oil feed stream with a first deoxygenating catalyst in a first bed of a reactor in the presence of hydrogen at first hydroprocessing conditions effective to form a low-oxygen biomass-derived pyrolysis oil;   introducing a hydrogen stream to the reactor between the first bed and a second bed to adjust the ratio of hydrogen to hydrocarbon in the second bed and to adjust a temperature in the second bed;   contacting the low-oxygen biomass-derived pyrolysis oil with a hydrocracking catalyst in a second bed of the reactor in the presence of hydrogen at hydrocracking conditions effective to form a hydrocracked low-oxygen biomass-derived pyrolysis oil effluent;   wherein a portion of the hydrocracked low-oxygen biomass-derived pyrolysis oil effluent comprises the heated low-oxygen biomass-derived py-oil diluent recycle stream.   
     
     
         17 . The method of  claim 16 :
 wherein contacting the heated diluted py-oil feed stream comprises contacting the heated diluted py-oil feed stream with the first deoxygenating catalyst at the first hydroprocessing conditions that include a reaction temperature of from about 150° C. to about 400° C.;   or   wherein contacting the low-oxygen biomass-derived pyrolysis oil comprises contacting the low-oxygen biomass-derived pyrolysis oil with the hydrocracking catalyst at the hydrocracking conditions that include a reaction temperature of from about 150° C. to about 500° C.;   or both.   
     
     
         18 . The method of  claim 16  wherein contacting the heated diluted py-oil feed stream comprises partially deoxygenating the heated diluted py-oil feed stream to form the low-oxygen biomass-derived pyrolysis oil that comprises a hydroprocessed organic phase that has a residual oxygen content of from about 5 to about 25 wt % of the hydroprocessed organic phase. 
     
     
         19 . The method of  claim 16  wherein combining comprises combining the biomass-derived pyrolysis oil stream with the heated low-oxygen-py-oil diluent recycle stream at a predetermined recycle ratio of from about 1:1 to about 10:1, wherein the predetermined recycle ratio is defined by a recycle mass flow rate of the heated low-oxygen-py-oil diluent recycle stream to a py-oil mass flow rate of the biomass-derived pyrolysis oil stream. 
     
     
         20 . The method of  claim 16  further comprising:
 removing water from and separating the hydrocracked low-oxygen biomass-derived pyrolysis oil effluent to form a water-depleted low-oxygen py-oil intermediate stream; and 
 contacting the water-depleted low-oxygen py-oil intermediate stream with a second deoxygenating catalyst in the presence of hydrogen at second hydroprocessing conditions effective to form an ultralow-oxygen biomass-derived pyrolysis oil effluent.