Process for conversion of a cellulosic material

Abstract

A process for the high temperature conversion of a cellulosic material into a bio-oil, wherein, under hydrogen atmosphere and in the presence of a catalyst, the cellulosic material is contacted in a reaction vessel with a liquid solvent, wherein water is present from 5% up to 80 wt %, based on the total amount of cellulosic material and liquid solvent present in the vessel, at an a controlled operating pressure of from equal to or more than 2.0 MPa to equal to or less than 13.0 MPa, wherein the partial hydrogen pressure contributes from equal to or more than 1.0 MPa to equal to or less than 6.0 MPa, and the total vapour pressure being lower than the autogenous pressure at the operating temperature and contributing in the range of from equal to or more than 1.0 MPa to equal to or less than 7.0 MPa, to produce a product mixture comprising bio-oil.

We claim: 
     
         1 . A process for the high temperature conversion of a cellulosic material into a bio-oil, wherein,
 under hydrogen atmosphere and in the presence of a catalyst, the cellulosic material is contacted in a reaction vessel with a liquid solvent, wherein water is present from 5% up to 80 wt %, based on the total amount of cellulosic material and liquid solvent present in the vessel, at an operating temperature in the range from equal to or more than 180° C. to equal to or less than 300° C., and at a controlled operating pressure of from equal to or more than 2.0 MPa to equal to or less than 13.0 MPa, wherein the partial hydrogen pressure contributes from equal to or more than 1.0 MPa to equal to or less than 6.0 MPa, and the total vapour pressure being lower than the autogenous pressure at the operating temperature and contributing in the range of from equal to or more than 1.0 MPa to equal to or less than 7.0 MPa, to produce a product mixture comprising bio-oil.   
     
     
         2 . The process of  claim 1  wherein the operating pressure is from equal to or more than 3.5 MPa, equal to or more than 4.2 MPa, to equal to or less than 11.0 MPa, preferably equal to or less than 10.0 MPa, wherein the partial hydrogen pressure contributes respectively from equal to or more than 1.0 MPa, to equal to or less than 5.0 MPa, and
 wherein the total vapour pressure contributes respectively in the range from equal to or more than 2.0 MPa, to equal to or less than 6.0 MPa. 
 
     
     
         3 . The process of  claim 1  wherein the reaction vessel is provided with a pressure control system that opens a pressurization valve and shuts it once the internal pressure has reached a certain setpoint in the desired operating pressure range. 
     
     
         4 . The process of  claim 1  wherein the reaction vessel is equipped with an open gas restriction outlet that leads to a compartment of low but controlled pressure. 
     
     
         5 . The process of  claim 1  wherein the cellulosic material comprises from 2 to 50 wt % of water based on the total amount of cellulosic material, when introduced into the reaction vessel. 
     
     
         6 . The process of  claim 1  wherein the catalyst is a sulfided catalyst comprising cobalt and molybdenum, optionally comprising a promoter. 
     
     
         7 . The process of  claim 1  wherein liquid solvent has a vapour pressure at the operating temperature that is lower than the operating pressure. 
     
     
         8 . The process of  claim 7  wherein liquid solvent is liquid at a temperature in the range from equal to or more than 180° C. to equal to or less than 300° C. at a pressure of 0.1 MPa. 
     
     
         9 . The process of  claim 1  wherein the liquid solvent is an organic solvent. 
     
     
         10 . The process of  claim 9  wherein the organic solvent comprises one or more carboxylic acids. 
     
     
         11 . The process of  claim 9  wherein the organic solvent comprises paraffinic compounds, naphthenic compounds, olefinic compounds and/or aromatic compounds. 
     
     
         12 . The process of  claim 9  wherein the organic solvent comprises at least one phenolic group, optionally substituted with side groups. 
     
     
         13 . The process of  claim 1  wherein the process further comprises recycling a part of the product mixture having a vapour pressure at the operating temperature that is lower than the operating pressure, to be used as part of the liquid solvent. 
     
     
         14 . The process of  claim 1  wherein the process further comprises a subsequent step wherein the product mixture is separated into a light fraction comprising compounds having a molecular weight of less than 100 grams per mol; a middle fraction comprising compounds having a molecular weight in the range from equal to or more than 100 grams per mol to equal to or less than 1,000 grams per mol; and a heavy fraction comprising compounds having a molecular weight of more than 1,000 grams per mol. 
     
     
         15 . The process of  claim 14  wherein at least 30 wt % of the liquid solvent used in the conversion process consists of recycled product mixture middle fraction. 
     
     
         16 . The process of  claim 2  wherein the operating pressure is from equal to or more than 4.2 MPa, to equal to or less than 10.0 MPa.