Provided is a biomass gasification and carbon capture coupled system to solve the problem that how to realize efficient utilization of the biomass energy, effective emission reduction of the carbon dioxide (CO.sub.2), and low-cost production of the alkaline compounds. The biomass gasification and carbon capture coupled system includes a fluidized bed device configured to gasify a biomass raw material, where an output end of the fluidized bed device is connected to a pressure swing adsorption (PSA) device; an output end of the PSA device is connected to an ammonia (NH.sub.3) production device; an output end of the NH.sub.3 production device is connected to a carbon capture device; the PSA device is further connected to a heat utilization device; and the heat utilization device is configured to provide heat energy for the NH.sub.3 production device.

A method for stripping CO.sub.2 from a biocatalyst-containing CO.sub.2-rich absorption solution to produce a biocatalyst-containing CO.sub.2-lean absorption solution and a CO.sub.2-rich gas is provided. The method includes generating a stripping gas from a portion of the biocatalyst-containing CO.sub.2-lean absorption solution in a stripping gas generation unit, and contacting the biocatalyst-containing CO.sub.2-rich absorption solution with the stripping gas in a gas-liquid contactor to produce the CO.sub.2-lean absorption solution and the CO.sub.2-rich gas.