Integrated direct air capture and CO2 utilization of gas fertilizer based on moisture swing adsorption

• Published in: Journal of Zhejiang University. A. Science 2017-10, Vol.18 (10), p.819-830
• Main Authors: Hou, Cheng-long, Wu, Yu-song, Jiao, You-zhou, Huang, Jie, Wang, Tao, Fang, Meng-xiang, Zhou, Hui
• Format: Article
• Language: English
• Subjects: Adsorption; Agricultural economics; Carbon dioxide; Carbon sources; Civil Engineering; Classical and Continuum Physics; Cultivation; Desorption; Energy requirements; Engineering; Fertilization; Fertilizers; Industrial Chemistry/Chemical Engineering; Light intensity; Luminous intensity; Mechanical Engineering; Moisture; Sustainable agriculture
• ISSN: 1673-565X; 1862-1775
• DOI: 10.1631/jzus.A1700351

A new concept of low-cost direct air capture technology integrated with a fertilization system is proposed, as an alternative to the application of air derived CO 2 . A moisture swing sorbent can elevate the CO 2 concentration from 400 parts per million (ppm) to several thousand ppm, and this can be used to cultivate plants. Desorption isotherms were determined and are described well by a Langmuir model. The adsorption rate constant and the desorption rate constant were gained at 25 °C, 35 °C, and 45 °C under 1000 ppm concentration of CO 2 . In accelerated cultivation experiments, the effects of CO 2 concentration, light intensity, and spectrum on the CO 2 uptake rate of the plants were investigated. A multi-bed desorption system which is capable of providing a continuous and stable CO 2 supply for a greenhouse is demonstrated based on the desorption characteristic and CO 2 uptake feature of plants. An energy and cost assessment for the integrated system was performed and the results indicated that minimum energy requirements and cost estimate of CO 2 are 35.67 kJ/mol and 34.68 USD/t, respectively. This makes direct air capture a competitive and sustainable carbon source for agriculture.