Measurement of Physicochemical Properties and CO₂, N₂, Ar, O₂, and H₂O Unary Adsorption Isotherms of Purolite A110 and Lewatit VP OC 1065 for Application in Direct Air Capture

Abstract

Direct air capture (DAC) using solid adsorbents has gained significant attention as a carbon dioxide removal (CDR) technology to help limit global temperature rise to below 2 °C. One large area of focus is the development of new adsorbent materials for DAC. However, the necessary data needed to employ these materials in process models for adsorbent screening are rarely available. Here, we showcase Purolite A110, a commercially available amine-functionalized polymeric resin, as a new candidate adsorbent for DAC and compare its properties to a current benchmark, Lewatit VP OC 1065. For both materials, we report their chemical features and composition, skeletal, particle, and bed density, total pore volume, particle porosity, BET area, thermal stability, and specific heat capacity. We determine their equilibrium sorption properties by measuring the volumetric CO 2 isotherms at 288, 298, 308, 333, 343, 353, and 393 K, N 2 and H 2 O isotherms at 288, 298, and 308 K, and Ar and O 2 isotherms at 298 K. For CO 2 , N 2 , and H 2 O, we also present the corresponding isotherm model fitting parameters and heats of adsorption. These data can help facilitate process modeling and optimization studies to properly assess these adsorbents at scale.

Steam Adsorption Equilibrium Data at 110 °C on Activated Carbon, Lewatit VP OC 1065, and CALF-20 Using a Microscale Dynamic Column Breakthrough Apparatus

“…Some equilibrium points were measured but had too much error associated with them to be included in this manuscript or had an anemometer reading above 4 V. They are shown in Table with a dash and are specifically adsorption loadings at y H 2 normalO = 0.147 , 0.186, and 0.314. The calculated data displays a type-3 isotherm shape and is consistent with the data previously measured on the material. , The H 2 O loadings initially appear linear (type-1) to y H 2 normalO = 0.661 . At this point, the isotherm slope begins to increase as a type-3 isotherm.…”

“…Only the adsorption branch of the data by Low et al is shown in Figure f. The same type-3 isotherm shape is seen in all three data sets. , As was observed for both activated carbon and CALF-20, the low-temperature data at 25 °C is consistently greater than our data at 110 °C. The topography of the steam isotherms for all three materials bears a strong resemblance to that of their low-temperature H 2 O isotherm counterparts.…”

“…The Guggenheim-Anderson-De Boer (GAB) isotherm was chosen to model the type-3 isotherms. This isotherm model is widely used for H 2 O on amine-functionalized materials with particular applications in direct-air capture. ,, This is partially due to its ability to model type 1, 2, and 3 isotherm shapes depending on the value of its parameters . The formula describing the GAB isotherm is shown in eq . q H 2 normalO * = q b normals normala normalt c H 2 normalO b H 2 normalO x H 2 normalO ( 1 − b normalH 2 O x normalH 2 O ) ( 1 + false( c H 2 normalO − 1 false) b normalH 2 O x normalH 2 O ) where q b sat is the monolayer saturation capacity of the adsorbent, b H 2 normalO is a nonlinearity constant, c H 2 normalO is the second nonlinearity constant and a parameter that determines the isotherm shape (either type-2 and type-3), and x …”

“…26 Figure 7f shows the same isotherm data plotted in relative pressure, with a comparison of low-temperature data (25 °C) by Low et al (blue circles). 36 Only the adsorption branch of the data by Low et al is shown in Figure 7f. The same type-3 isotherm shape is seen in all three data sets.…”

“…Lewatit is an amine-functionalized polymeric material that has been studied for DAC applications. 7,26,36 For this set of experiments, 156.4 mg of All experiments were performed at 110 °C. The subscript "in" refers to the inlet adsorption flow, while the subscript "init" refers to the inlet desorption flow.…”