Process for producing synthesis gas

Abstract

A process for controlling the carbon conversion of a gasifier fuelled with a carbonaceous feedstock by mixing in biomass, the process comprising the steps of (a) pressurizing the biomass and carbonaceous feedstock; (b) introducing the biomass and carbonaceous feedstock into the gasification reactor vessel; (c) partially oxidizing the carbonaceous feedstock/biomass with a molecular oxygen-comprising gas to obtain a synthesis gas comprising carbon monoxide and hydrogen; (d) measuring the C02 content of the syngas and comparing with a pre-determined value range; (e) adjusting the biomass/carbonaceous feedstock ratio by changing the biomass feed rate; wherein said biomass and carbonaceous feedstock comprises from 10 wt % to 50 wt % of biomass and wherein the level of biomass is adjusted within this range to control the carbon conversion.

1 . A process for controlling the carbon conversion of a gasifier fuelled with a carbonaceous feedstock by mixing in biomass, the process comprising the steps of
 (a) pressurizing the biomass and carbonaceous feedstock;   (b) introducing the biomass and carbonaceous feedstock into the gasification reactor vessel;   (c) partially oxidizing the carbonaceous feedstock/biomass with a molecular oxygen-comprising gas to obtain a synthesis gas comprising carbon monoxide and hydrogen;   (d) measuring the CO2 content of the syngas and comparing with a pre-determined value range;   (e) adjusting the biomass/carbonaceous feedstock ratio by changing the biomass feed rate;   
       wherein said biomass and carbonaceous feedstock comprises from 10 wt % to 50 wt % of biomass and wherein the level of biomass is adjusted within this range to control the carbon conversion. 
     
     
         2 . A process according to  claim 1 , wherein the carbonaceous feedstock and biomass are separately introduced into the gasification reactor. 
     
     
         3 . A process according to  claim 1 , wherein the carbonaceous feedstock and biomass are introduced in the gasification reactor as a mixture. 
     
     
         4 . A process according to  claim 1 , wherein the feedstock to the gasifier comprises from 10 wt % to 30 wt % of biomass fuel. 
     
     
         5 . A process according to  claim 1 , wherein the biomass is a solid biomass as obtained by torrefaction. 
     
     
         6 . A process according to  claim 1 , wherein the biomass is a solid biomass as obtained by slow pyrolysis of a biomass source. 
     
     
         7 . A process according to  claim 1 , wherein the biomass is a solid biomass as obtained by flash pyrolysis of a biomass source. 
     
     
         8 . A process according to  claim 4 , wherein the biomass is a liquid biomass as obtained by flash pyrolysis of a biomass source. 
     
     
         9 . A process according to  claim 4 , wherein the biomass is a slurry biomass consisting of a mixture of pyrolysis oil and char as obtained by flash pyrolysis of a biomass source. 
     
     
         10 . A process according to  claim 1 , wherein the carbonaceous feedstock is coal. 
     
     
         11 . A process according to  claim 1 , wherein the carbonaceous feedstock is oil residue. 
     
     
         12 . A process according to  claim 1 , wherein in step (c) the carbonaceous feedstock/biomass fuel mixture and the molecular oxygen comprising gas are converted to synthesis gas by providing said reactants to a burner as present in a gasification reactor at a pressure of between 1 and 10 MPa. 
     
     
         13 . A process according to  claim 1 , wherein in step (d) the CO2 content is measured using an infrared based analyser. 
     
     
         14 . A process according to  claim 1 , wherein, in step (e) a controller will adjust the biomass/coal ratio by changing the set-point of a biomass feed rate controller.