O-08　Determination of Acidic Groups in the Char Prepared from Wood and its Constituent Polymers by the Modified Boehm Method

Abstract

Acidic groups such as carboxylic and phenolic groups are associated with the physicochemical properties of biochar as a soil amendment. Generally, the Boehm method has been used for the measurement of acidic groups, but due to the use of titration, a large amount of biochar is required for the measurement. To study the evolution of these acidic groups in char in more detail, a smaller scale method is desirable. Also, alkali and alkaline earth metal cations in wood may interfere with accurate determination. In this paper, we propose a small-scale modified Boehm method using ash content measurement instead of titration. Influences of pyrolysis temperature (400-1000°C) on the development of carboxylic and phenolic groups were also studied for the carbonization of Japanese cedar (Cryptomeria japonica, Sugi) and its Klason lignin and cellulose (Avicel).