Method for reducing carbon dioxide to manufacture multi-carbon hydrocarbon compound

A method for reducing carbon dioxide to manufacture a multi-carbon hydrocarbon compound, comprising:

• providing a reduction reaction with separation and purification system, comprising:
• a carbon dioxide absorption tower having an absorbent;
• a reactor communicated to a liquid outlet of the carbon dioxide absorption tower and having a photocatalyst;
• a gas-liquid separation device communicated with the reactor, and the gas-liquid separation device connected with a liquid-phase tank and a gas-phase tank by a first flow path and a second flow path, respectively;
• a liquid-phase purification device communicated with the liquid-phase tank;
• and
• a gas-phase purification device comprising a washing tower and at least one separation column set, wherein the washing tower is communicated with the gas-phase tank, and the at least one separation column set is connected with the washing tower;
• performing an absorption step, wherein a carbon dioxide gas is performed a carbon dioxide absorption treatment by the absorbent in the carbon dioxide absorption tower to form a mixed solution;
• performing a photocatalysis step, wherein the mixed solution is reacted with the photocatalyst under an irradiation of a light source in the reactor to form a carbon-based compound;
• performing a separation step, wherein the carbon-based compound is separated by the gas-liquid separation device to form a liquid-phase mixture and a gas-phase mixture, which are stored in the liquid-phase tank and the gas-phase tank, respectively;
• performing a liquid-phase purification step, wherein the liquid-phase mixture is filtered and dried in the liquid-phase purification device to purify the liquid-phase mixture;
• and
• performing a gas-phase purification step, wherein the gas-phase mixture is washed by the washing tower, and separated and purified the gas-phase mixture in the at least one separation column set by a pressure swing adsorption method in the gas-phase purification device to form a multi-carbon hydrocarbon compound.