The Effect of different Humidity Profles on the energetic and economic Performance of a Solid Sorbent Direct Air Capture Unit in a Multi Energy System - A case study for California and the Netherlands -

Abstract

Direct Air Capture (DAC) is a novel technology allowing CO2 to be sequestrated from ambient air. Solid Sorbent DAC units constitute a promising research strand capable of utilizing low-temperature waste heat and electricity to produce a pure stream of CO2 from ambient air. However, energy requirements and productivity depend on the relative humidity. This study models a DAC unit in a multi energy system at different locations. Required to produce a certain amount of CO2 over the modeled year, the effect of changes in relative humidity on the energetic and economic performance of the technology can be studied. California, with dry conditions and large renewable energy resources and the Netherlands, with more humid conditions and lower renewable energy resources have been chosen as two exemplary locations. The results suggest a trade off between energy requirements and productivity. Dry conditions reduce the maximal possible productivity of the DAC units, but also reduce total energy demand. Thus, larger DAC modules are required at dry locations compared to humid locations. Despite lower energy requirements at dry locations, the increased investment costs outbalance energy cost savings. In a multi energy system with renewable energy generation, upscaling of the CO2 demand however, can reduce total system costs by synergies on the generation side.