Fossil fuels are still the most important source for supplying the world＇s energy and heating needs. The growing demands of more stringent pollution control regulations make it necessary to develop new flue gas cleaning processes. Up to now there is no known process that allows the dry separation of hydrogen chloride from flue gases with ready adsorbent regeneration. The well known BF-Uhde process cannot be applied to flue gases containing hydrogen chloride. Our-aim was to develop a process for dry separation of hydrogen chloride from flue gases that can be used in combination with the BF-Uhde process. The new process is based on a gas-solid reaction between active magnesia and hydrogen chloride at temperatures of about 120 degrees C. The new process performed well in experiments conducted under industrial conditions, The adsorbent can be regenerated at temperatures of about 450 degrees C. Hydrogen fluoride is the only known flue gas component that interferes with the regeneration capability of the adsorbent.