Solar-driven integrated device for simultaneous direct air capture and atmospheric water harvesting

초록

The demand for freshwater production and achieving carbon neutrality has become a global challenge for human society. Herein, a solar-driven integrated device is proposed for simultaneous atmospheric water harvesting and direct air capture (AWH-DAC device) without electrical heat for desorption. During nighttime, ambient air with CO2 flows into the AWH-DAC device, followed by adsorption of moisture and CO2. During daytime, water production and CO2 desorption are driven by sunlight and natural convection cooling from condenser, resulting economic energy efficiency. The AWH-DAC device demonstrates notable performance of water production in the outdoor experiments, exhibiting water harvesting productivity of 0.89 L & sdot;m 2 & sdot;day 1 and consumption of energy input per water production of 5.77 kWh & sdot;L 1. Moreover, compared with conventional DAC plants, the AWH-DAC device demonstrates stable CO2 desorption in the outdoor experiments without electrical energy consumption for the desorption heat. The estimation of the total cost shows 82-204 & sdot;tCO21 to operate the AWH-DAC device for DAC applications, achieving an average cost reduction of 12% for adsorption-based DAC and 84% for absorption-based DAC compared with the total cost of conventional plants. In greenhouse applications, the AWH-DAC device can provide the cost savings of1-3 & sdot;t 1sorbent & sdot;day 1 for water irrigation and $22-65 & sdot;t1sorbent & sdot;day 1 for CO2 enrichment. Moreover, the overall desorption process of the AWH-DAC device is mainly driven by solar heat solely, suggesting cost-effective advantages for industrial applications without additional energy consumption for desorption. This work establishes an approach for freshwater production and CO2 mitigation simultaneously, thereby alleviating not only water scarcity and global warming but also energy shortages by mainly utilizing renewable energy.

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