Abstract: Hydrotreating of normally liquid hydrocarbon feeds has long been practiced to convert organic sulfur compounds to hydrogen sulfide for subsequent removal by adsorption. It has now been found that hydrotreating of said feed stocks over a nickel molybdenum oxide or cobalt molybdenum oxide catalyst also converts trace quantities of organic chloride compound to HCl which not only is a poison for catalysts in subsequent reactions but seriously reduces the sulfur retention capacity of zinc oxide sulfur adsorbents. A solid chloride adsorbent having a chloride retention capacity some twentyfold greater than known adsorbents has been developed for the sequential removal of hydrogen chloride contaminants in trace quantities to a level of less than one part per million in hydrogen treated streams. This adsorbent serves as a guard for catalysts in subsequent catalytic processes as well as a guard for the solid sulfur adsorbent utilized immediately downstream therefrom.