HFC-23 Decomposition by Energy-Efficient Plasma Processing and Its Feasibility Study for CDM Project

摘要

Many countries in the world are making an effort towards reducing GHG (Green House Gas) for Post 2012. The CDM projects for decomposition of HFC-23 (CHF_3), which is generated as a by-product of HCFC-22 (CHCIF_2) production process, have been in active operation for the last several years due to its high Global Warming Potential (GWP) which is 11,700 times than that of CO_2. The incineration process using natural gas and hydrogen as primary fuels has been generally applied to most of the CDM projects for the decomposition of HFC-23 because of its relatively easy process control, moderate cost, and big treatment capacity. However, this process inevitably results in the secondary pollutant such as NOx, SOx, etc, and also has an inherent explosion hazard from flammable gases. We expect that these problems can be in part overcome by combining or replacing with an energy-efficient plasma technology. Our simulation data reveal that a plasma process for the decomposition of 30kg/hr of HFC-23 only requires 8.48kW of electricity, which corresponds to 26Nm~3/hr of natural gas. Consequently, it can reduce 2.8 million tons of CO_2 eq/yr of GHG emission with minimizing secondary pollution. However, some practical obstacles still remain before this process can be deployed on a mainstream technology for the HFC-23 decomposition. We discuss the important factors that must be considered along with possible solutions.