Yields from agriculture can be enhanced by maintaining elevated CO₂ environments typically in the range of 1000 ppm CO₂. Technologies that have the potential to supply these elevated CO₂ levels in a carbon neutral manner can improve agricultural yields whilst mitigating further CO₂ emissions. Direct air capture (DAC) is one such technology that captures and concentrates CO₂ from the atmosphere. Most current DAC research focuses on producing high concentrations of CO₂ which typically requires high temperature/pressure swings in order to achieve high purity CO₂ streams. These conditions complicate plant design and affect the longevity of the material. This study explores the possibility of producing CO₂ at suitable concentrations for agricultural yield enhancement using mild desorption conditions (50 °C and no pressure swing). A novel crosslinked polyamine formula utilising non-hazardous liquid components was developed in order to be more aligned to agricultural exposure limits. 1000 ppm CO₂ could be maintained during desorption with air flow at 50 °C (with no vacuum) for up to 70 % of the materials working capacity of 3.8 wt% CO₂. The longevity of the material was enhanced due to the lower desorption temperature as evidenced by no reduction in working capacity after 30 days exposure to desorption conditions (equivalent to 205 cycles).Compared to a previous work utilising the commercially available Lewatit VP OC 1065, the Lewatit resin had a repeated cyclic uptake of 4.1% wt. % CO₂ compared to 3.8 wt% for the polymer used in this study.

中文翻译：

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用于温室 CO2 富集的超低挥发性固体多胺 CO2 捕集材料


通过将 CO₂ 保持在 1000 ppm_CO2 的范围内，可以提高农业产量。有可能以碳中和方式供应这些升高的 CO₂ 水平的技术可以提高农业产量，同时进一步减少 CO₂ 排放。直接空气捕获 （DAC） 就是这样一种从大气中捕获和浓缩 CO₂ 的技术。目前的大多数 DAC 研究都集中在产生高浓度的 CO₂ 上，这通常需要高温/高压波动才能获得高纯度的 CO₂ 流。这些条件使工厂设计复杂化，并影响材料的使用寿命。本研究探讨了使用温和的解吸条件（50 °C 且无压力波动）生产合适浓度的 CO₂ 以提高农业产量的可能性。开发了一种利用无害液体成分的新型交联多胺配方，以便更符合农业暴露限值。在解吸过程中，在 50 °C（无真空）的气流下，可以保持 1000 ppm 的 CO₂，最高可达 3.8 wt% CO₂ 材料工作能力的 70%。由于解吸温度较低，材料的使用寿命得到了延长，这可以从暴露于解吸条件 30 天（相当于 205 次循环）后工作能力没有降低中得到证明。与之前使用市售 Lewatit VP OC 1065 的工作相比，Lewatit 树脂具有 4.1% wt. % CO₂ 的重复循环吸收，而本研究中使用的聚合物为 3.8 wt%。