The invention relates to a method for
processing Fischer-Tropsch synthesis
tail gas, which comprises the steps of
decarburization, membrane separation, low temperature oil washing,
tail gas conversion and
pressure swing adsorption(PSA). The method is characterized in that
tail gas from a Fischer-Tropsch synthesis apparatus is passed through a
decarburization unit for removing CO2 component;
decarburization tail gas is sent to a membrane separation unit for recovering
hydrogen, membrane separation penetration gas with rich
hydrogen is boosted and then sent to a PSA unit for
hydrogen production, also can be returned to the Fischer-Tropsch synthesis apparatus after boosting, the membrane separation unit can be returned to the Fischer-Tropsch synthesis apparatus according to the required gas with any H2 / CO proportion, membrane separation non-penetration gas can be passed through a low temperature oil washing unit for recovering liquefied gas component and then sending to a tail gas conversion unit, and also can be sent to the tail gas conversion unit directly for
hydrogen production; in the tail gas conversion unit, oil washing
dry gas or membrane separation non-penetration gas are conversed,
methane and hydrocarbons components are conversed to crude synthetic gas; the conversed crude synthetic gas converses CO and H2O to CO2 and H2, the conversed gas after decarburization removes CO2 to obtain hydrogen rich gas, the hydrogen rich gas is passed through the PSA unit for recovering hydrogen, hydrogen in the PSA unit can be used for whole
plant, the analytic gas can be used as
fuel gas.