The invention discloses a method and a device for capturing and utilizing
carbon dioxide and application of the method and the device. The method and the device are used for capturing CO2 from high-temperature gas containing
carbon dioxide and converting the CO2 into synthesis gas in situ. The
carbon dioxide-containing gas enters the adsorption reactor from an inlet of the adsorption reactor and passes through a catalyst
bed layer of the adsorption reactor, carbon dioxide in the carbon dioxide-containing gas is adsorbed by the catalyst
bed layer, and purified gas leaves the adsorption reactor from an outlet of the adsorption reactor; reducing gas and circulating gas are mixed to serve as mixed circulating gas, the mixed circulating gas exchanges heat with synthesis gas at an outlet of the conversion reactor, is heated by a heater, enters the conversion reactor from an inlet of the conversion reactor and passes through a catalyst
bed layer of the conversion reactor, and carbon dioxide adsorbed on the catalyst bed layer of the conversion reactor is converted into synthesis gas. After leaving from an outlet of the conversion reactor, the synthesis gas firstly exchanges heat with mixed circulating gas, is cooled by a cooler and boosted by a circulating compressor, and is divided into two streams, one
stream is taken as
product gas to be sent out, and the other
stream is taken as circulating gas to be mixed with reducing gas to be sent to the conversion reactor; feeding and subsequent procedures of the adsorption reactor and the conversion reactor are periodically switched. By means of the device, the energy
utilization rate can be fully increased, the emission reduction cost is effectively reduced, and heat in-situ
coupling utilization in the adsorption heat release / conversion heat absorption process can be achieved.