Capture and recovery of organic vapors with an electrothermal-swing adsorption system

There are 740 Gg of hazardous chemicals that are emitted to the atmosphere each year. The United States Environmental Protection Agency (USEPA) mandates the reduction in the emission of these chemicals, of which many of them are organic vapors. A novel electrothermal-swing adsorption (ESA) system that uses activated carbon fiber cloth (ACFC) is an effective means to capture and recover these organic vapors from industrial gas streams to meet USEPA standards. This ESA system incorporates the unique physical and chemical properties of the ACFC with the direct application of electric energy to the ACFC during electrothermal regeneration.; A pilot-scale ACFC-ESA system was designed, developed, evaluated and characterized to demonstrate the effectiveness of this new technology. The ESA system captured organic vapors from gas streams on a continuous basis and recovered them as pure liquid condensates for reuse. The gas streams contained low concentration of organic vapors typical of numerous industrial operations.; Modeled and measured material and energy balances characterized the pilot-scale unit. Properties of ACFC such as equilibrium adsorption capacity and heats of adsorption of organic vapors were determined as inputs for mass and energy balances. The organic adsorbate that entered the ESA system partitioned as vapor with the air that exhausted from the ESA system, as adsorbed material that remained in the ACFC cartridges, and as recovered organic liquid. The electrical energy applied to the cartridges was balanced with the energy change of the organic vapor, the ambient air, the N2 as purge gas, the ACFC adsorbent, and the fitting materials used in the adsorption vessel. Removal efficiencies for organic vapors >99% and liquid recovery efficiencies >67% were achieved with the pilot system.; Applications of the ESA technology for the capture and recovery of organic vapors is very encouraging. The new ESA system allowed for rapid electrothermal regeneration and condensation of the adsorbate. This investigation demonstrated the ESA technology's feasibility to successfully operate under realistic conditions for the air quality industry and allow us one step closer to achieving goals for sustainable development.