PROCESS FOR PRODUCING SYNTHESIS GAS
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.