Abstract: Due to gas-liquid entrainment，there are large amounts of fluorinated aromatic hydrocarbons or phenolic organic compounds in the byproduct hydrogen chloride gas released in the chlorination and hydrolysis processes of fluorinated hydro- carbons，such as 2-chloro-6-fluorobenzyl chloride，2-chloro-6-fluorobenzaldehyde，and 2-chloro-6-fluoro-3-methoxy- benzoic acid.Without purification，the acid would not only be useless，but also requires harmless treatment，leading to increased production cost and elevated discharge of Three Wastes.Usually，lime or lye is used to neutralize the acid to achieve the goal of harmless treatment，and the solid waste and wastewater would be disposed respectively after separation of the liquid and solid.Since there are a large amount of organic contaminants and fluorinated compounds in the solid waste and wastewater，it is necessary to entrust qualified institutions for special disposal，which is of very high cost.A technology consisting of falling film absorption，natural subsidence，resin segmented adsorption，and removal of free chlorine was used to effectively dispose the byproduct hydrogen chloride，the quality of the hydrochloric acid obtained met the high-class products requirement of GB 320—2006，Industrial Synthetic Hydrochloric Acid，and could be sold as commercial hydrochloric acid.Project verification showed that the investment for the hydrochloric acid production apparatus with annual capacity of 10 000 t（after falling film absorption） was 300 000 RMB ￥，and the operation cost was only 25 RMB ￥/t，the annual direct economic benefit exceeded 5 000 000 RMB ￥，and the economic and social benefits were significant.

Key words: aromatic hydrocarbon containing fluorine, falling film absorption, by-product hydrogen chloride, macroporous adsorption resin, comprehensive treatment