NSF Award
9960540
This Small Business Innovation Research Phase I project will develop a novel electrochemical method of purification of "tail" gas, also known as vent or sniff gas. About half of the chlorine produced in the chlor-alkali industry is liquefied, stored, and shipped. The tail gas from the liquefaction process contains chlorine (Cl2) with oxygen (O2), nitrogen (N2), carbon dioxide (CO2), and hyrogen (H2) as impurities. Phase I involves reduction of Cl2 from the impure chlorine stream at a gas diffusion or porous flow-through type cathode. The product HCl is anodically oxidized to generate chemically pure Cl2. The other impurities in the impure Cl2 gas stream, e.g., N2, CO2, are either not reducible at the cathode or their reduction is too low to be significant. The objective of Phase I is high current density.operation, delineating the effects of impurities in the chlorine on cathode performance, and minimizing the contribution of parasitic reactions at the anode.<br/><br/>Commercially relevant benefits include: material conservation (Cl2 is not wasted), reduction in energy consumption relative to other technologies, elimination of waste gas streams, and generation of pure Cl2.
