Process for producing synthetic fuel

A process for the manufacture of a synthetic fuel comprising:

• a. gasifying a carbonaceous feedstock comprising waste materials and/or biomass to generate a raw synthesis gas comprising H2, CO, CO2, at least one other carbonaceous material comprising at least CH4 and tars, and contaminants comprising particulates, ammonia or HCl, and sulphurous gas;
• b. supplying at least a portion of the raw synthesis gas to a primary clean-up zone supplied with an aqueous stream at least partially to wash particulates and ammonia or HCl out of raw synthesis gas, the aqueous stream being selected to be a neutral or acidic aqueous stream when ammonia is a contaminant in the raw synthesis gas and being selected to comprise a basic aqueous stream when HCl is a contaminant in the raw synthesis gas, to provide an aqueous-washed raw synthesis gas comprising H2, CO, CO2 and contaminants comprising sulphurous gas;
• c. supplying at least a first part of the aqueous washed raw synthesis gas to a shift reaction or adjustment zone and shifting the H2 to CO ratio of the raw synthesis gas to a selected ratio to provide a shifted raw synthesis gas comprising H2, CO, and CO2 and contaminants comprising sulphurous gas;
• d. supplying at least a portion of the shifted raw synthesis gas to a secondary clean-up zone;
• e. contacting the shifted raw synthesis gas in the secondary clean-up zone with a physical solvent for sulphurous materials effective at least partially to absorb sulphurous materials from the shifted raw synthesis gas and recovering from the secondary clean-up zone an at least partially desulphurised, de-tarred shifted raw synthesis gas comprising H2, CO and CO2;
• f. supplying the at least partially desulphurised, de-tarred aqueous-washed raw synthesis gas to a tertiary clean-up zone;
• g. contacting the at least partially desulphurised, de-tarred shifted raw synthesis gas in the tertiary clean-up zone with a physical solvent for CO2 effective at least partially to absorb CO2 from the at least partially desulphurised, de-tarred shifted raw synthesis gas, and recovering from the tertiary clean-up zone a first stream comprising the physical solvent for CO2 and absorbed CO2, and a second stream comprising clean synthesis gas comprising H2, CO and optionally remaining contaminants;
• h. removing at least part of the absorbed CO2 from the first stream in a solvent regeneration stage to recover regenerated solvent and separately CO2 in a form sufficiently pure for sequestration or other use;
• and
• i. supplying the clean synthesis gas of the second stream, optionally after passage through one or more guard beds and/or alternative clean-up stages at least partially to remove any remaining contaminants, to a further reaction train to generate a synthetic fuel.