Performance of an electrothermal swing adsorption system with postdesorption liquefaction for organic gas capture and recovery

The use of adsorption on activated carbon fiber cloth (ACFC) followed by electrothermal swing adsorption (ESA) and postdesorption pressure and temperature control allows organic gases with boiling points below 0 C to be captured from air streams and recovered as liquids. This technology has the potential to be a more sustainable abatement technique when compared to thermal oxidation. In this paper, we determine the process performance and energy requirements of a gas recovery system (GRS) using ACFC-ESA for three adsorbates with relative pressures between 8.3 × 10^-5 and 3.4 × 10^-3 and boiling points as low as -26.3 C. The GRS is able to capture > 99% of the organic gas from the feed air stream, which is comparable to destruction efficiencies for thermal oxidizers. The energy used per liquid mole recovered ranges from 920 to 52 000 kJ/mol and is a function of relative pressure of the adsorbate in the feed gas. Quantifying the performance of the bench-scale gas recovery system in terms of its ability to remove organic gases from the adsorption stream and the energy required to liquefy the recovered organic gases is a critical step in developing new technologies to allow manufacturing to occur in a more sustainable manner. To our knowledge, this is the first time an ACFC-ESA system has been used to capture, recover, and liquefy organic compounds with vapor pressures as low as 8.3 × 10^-5 and the first time such a system has been analyzed for process performance and energy consumption.