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

Table 1

Experimental results for CO₂-adsorption on K₂CO₃-impregnated activated carbon. Experiments shown here comprise desorption at 120°C, with the exception of cycle 1, which was initially treated at 100°C before first adsorption.

Starting conditions			End conditions			Capacity^1	Cycle^2,3	Capacity corrected^1,4	Standard dev.^1
CO2	RH	T	CO2	RH	T
(ppm)	(%)	(°C)	(ppm)	(%)	(°C)	(mg g^-1)	#	(mg g^-1)	(mg g^-1)
1018	58.7	24.5	552	54.5	24.2	7.5	1	7.0	0.3
1069	56.9	25.2	660	46.9	25.4	6.6	5	6.1
1069	66.0	26.2	651	51.7	25.9	6.7	6	6.2
1044	51.6	23.8	596	44.6	24.3	7.2	7	6.7
1055	54.6	23.3	594	44.7	24.4	7.4	8	6.9	Arithm. mean^1
1076	47.7	24.3	625	43.5	24.7	7.3	9	6.8
1021	42.0	25.2	612	40.1	25.9	6.6	10	6.1	(mg g^-1)
1070	43.8	23.3	655	38.5	23.9	6.7	11	6.2	6.5
1013	60.7	23.1	565	44.9	23.8	7.2	12	6.8
1050	52.2	24.1	615	42.7	24.7	7.0	13	6.5

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).