"PREPARATION OF EFFICIENT CARBONACEOUS MATERIAL (ACTIVE CARBON) FROM HYDROLYSED LIGNIN THROUGH DIRECT ACTIVATION WITH PHOSPORIC ACID "

The increasing interest in bioethanol production from vegetal raw materials raises the question of utilizing waste hydrolysed lignin containing some quantity of cellulose. One possibility to solve this problem is to clarify the potential of using such residues for obtaining efficient carbonaceous materials through direct activation with phosphoric acid. It has been established that during the process of preparing active carbon, a decisive influence on the morphology of the prepared samples, as well as on the type of the obtained pores, is exerted by the preliminary wetting conditions of the samples and the chosen lignin:acid ratio. The greatest specific surface area was recorded for the sample treated with H 3 PO 4 at a ratio of 1:5, while the largest volume of the micropores -for the sample treated with H 3 PO 4 at a ratio of 1:1. In this investigation, active carbon samples possessing very good adsorption-textural parameters have been prepared, with specific surface area varying from 1029 up to 1824 m 2 /g, volume of the micropores ranging from about 0.320 up to 0.500 m 3 /g, and volumes of the mesopores varying within wide ranges, depending on the conditions of preparation.