PATENTS
To eliminate recycling, a 2-stage synthesis unit is operated in conjunction with a 2-stage coke-gasification unit. In the 1st gasification unit, steam and O2 are used to produce a product gas with H2:CO ratio of 1.0-1.5. This gas is fed to the 1st synthesis unit, where liquid hydrocarbons and a tail gas of high H2:CO ratio are produced with the aid of an Fe catalyst. Coke from the 1st gasification stage passes to a 2d stage, where it is gasified with CO2, O2, and steam to produce a gas with a H2:CO ratio of 0.5-0.8. This gas is mixed with the tail gas from the 2d stage to give a gas with a H2:CO ratio of 0.8-1.2, which is utilized in a 2d synthesis stage. |