Investigation of CO₂-Sorption Characteristics of Readily Available Solid Materials for Indoor Direct Air Capturing

Table 2

Experimental results for CO₂-adsorption on PEI-snow with a mass fraction of 3% and 6% TTE, respectively. Experiments shown here comprise desorption at three different temperatures.

	Starting conditions			End conditions			Reg. temp.	Capacity^1	Cycle^2,3	Cap. corr.^1,4	Standard dev.^1,6
	CO2	RH	T	CO2	RH	T
	(ppm)	(%)	(°C)	(ppm)	(%)	(°C)	(°C)^5	(mg g^-1)	#	(mg g^-1)	(mg g^-1)
3% TTE	1066	50.0	22.3	816	70.0	22.1	60	67.1	1	58.9	4.9
	1090	44.3	22.1	872	66.5	23.3	60	52.9	4	44.3
	1073	51.2	22.5	883	69.6	22.9	80	43.5	5	35.2
	1076	66.8	23.7	845	75.7	23.3	100	53.7	6	45.3
	1081	63.0	23.5	824	76.9	23.1	100	58.8	8	50.3
6% TTE	1079	57.4	25.2	718	61.1	24.5	100	66.5	2	58.1	Arithm. mean^1,6
	1035	68.3	24.3	807	74.2	25.0	100	60.1	3	52.3	(mg g^-1)
	1063	59.0	24.0	815	70.0	24.3	100	66.6	4	58.4	52.9

¹CO₂-adsorption capacity given in milligram CO₂ per gram adsorber material. ²Number of adsorption/desorption cycles for this material batch. ³Missing cycle numbers are not listed here because the corresponding experiments were conducted with different CO₂-concentrations and/or humidity. ⁴CO₂-adsorption capacity corrected for leakage according to Equation (1). ⁵Temperature used to regenerate material at 100 mbar for 1 hour prior to adsorption experiment. ⁶Standard deviation and arithmetic mean calculated only for experiments with adsorber fully regenerated at 100°C.