In this work the enhancement of ammonia adsorption on activated coke has been investigated to increase the efficiency of the denitrification in the dry flue gas cleaning system located at Infraserv GmbH & Co. Hoechst KG in Frankfurt am Main. Germany. The influence of loading temperatures and sulfur components content of the activated coke on the ammonia adsorption were studied. Additionally, urea was tested as an alternative loading substance. Increasing ammonia adsorption was observed by raising loading temperatures. The highest ammonia loading was possible at the highest temperature tested at 469 degrees C. The activated coke loaded at these conditions, as well as the one loaded with urea, was found to have higher denitrification efficiency than that loaded at present conditions of about 114 degrees C. The results of this study allowed the recommendation of possible measures to be applied in the plant to increase its denitrification efficiency. (c) 2010 Elsevier B.V. All rights reserved.