The invention provides a process method and
system for directly capturing
carbon dioxide from air and converting and utilizing the
carbon dioxide. The process method comprises the following steps: adsorbing
raw material gas through a
carbon dioxide trapping device, and heating and desorbing to obtain purified carbon dioxide gas; the purified carbon dioxide gas and the
electrolyte are subjected to electrocatalytic conversion to obtain synthesis gas,
oxygen and condensate water, and the condensate water is recycled through
water treatment operation to be used for supplementing the
electrolyte; the method comprises the following steps: carrying out Fischer-Tropsch synthesis reaction, hydrocracking and
isomerization reaction on synthesis gas to obtain an isomerized oil-gas mixture, wherein
heat energy generated by the reaction provides heating
desorption heat; and carrying out gas-liquid separation on the heterogeneous oil-gas mixture to obtain
combustible gas and an upgraded oil product, carrying out rectification operation on the upgraded oil product to obtain an SAF component and a heavy oil product, and carrying out
oxygen-enriched
combustion reaction on the
combustible gas and
oxygen to provide heating
desorption heat or supply required
heat energy. An integrated and flexible
industrial technology platform is developed, carbon capture and conversion processes are seamlessly connected, full-chain optimization from CO2 removal to high-added-value product generation is realized, and self
heat energy requirements and
wastewater utilization can be met.