A Long-Life, Low-Cost Sorbent for the Conversion of HCl to Chlorine

The U.S. demand for chlorinated hydrocarbons exceeds 15 million tons annually. The production of these chemicals requires chlorine (Cl2) and produces HCl as an unavoidable by-product. Stringent environmental regulations limit the shipment of hazardous wastes like HCl, and the disposal of HCl by neutralization is costly. A consortium of 15 companies is developing an in-process recycling system to oxidize the waste HCl into chlorine, which is internally recycled to the chlorinator. Unfortunately, due to equilibrium constraints, even when pure O2 is used as the oxidant, not all of the HCl can be converted back to Cl2. Thus, the process incorporates a second stage sorbent, CuO, which removes the residual HCl and recycles it back to the oxidizer. Because the Cl2 loading on the current sorbent is low, contribution of the sorbent to the process cost is high. TDA Research, Inc. (TDA) has developed long-life sorbents with high loadings of the chemically active materials for hot gas and flue gas cleanup applications. In this Phase I project, TDA will apply its technology to improve the CuO sorbent. During Phase I, TDA will develop a new sorbent for the conversion of HCl to Cl2. Several formulations will be evaluated, and one sorbent will be exposed to several cycles in the Product Development Unit (PDU). TDA also will evaluate the economics of the approach. It is anticipated that the sorbent loading will be improved by a factor of five over the current sorbent. This improvement will reduce the sorbent replacement cost by a factor of five and the cost of chlorine recovery by about a factor of two, greatly improving the economics of the chlorine recovery process.