Analysis of Biochar from Different Kinds of Feedstock and Varying Pyrolysis Temperature II: Analysis of Biochar from a Local Kiln

Publication Type

Journal contribution (peer reviewed)

Authors

Tyayon, P; Spreer, W; Wuttisathitthaworn, N; Lammwut, K; Karaj, S; Intani, K; Sringarm, K; Santasup, C; Müller, J

Year of publication

2016

Published in

Journal of Agriculture

Band/Volume

32/4

ISBN / ISSN / eISSN

0857_0841

Page (from - to)

55-61

Keywords

Longan, Reisstroh / Rice straw

In Thailand, due to seasonal floods and air pollution, soil and water conservation in highland areas have gained increasing attention, and bio-char is one option to use otherwise non-utilized biomass in a sustainable way, conserving soil fertility and improving the water holding capacity of a site. Bio-char can be made in small kilns, built from locally available materials and used at any terrain even by poor farmers. In the presented study different materials were tested, which are typical harvesting residues or materials, which are used in fallow management, namely: corn cobs, rice straw, bamboo, longan prunings. Three samples of each material were pyrolyzed in an experimental kiln at four different temperatures at 300 – 500 °C, with one hour exposition time. For comparison the same materials were pyrolyzed in a simple, locally built kiln. During the burning process a temperature profile was determined in the burning chamber. The experiment was repeated three times for each material. The dry weight of the samples was measured before and after bio-char production. The resulting bio-char was ground and analyzed on elementary composition, pH and organic matter content. While biochar has generally low contents of macro nutrients, the content of some micro nutrients may be important. The local kiln produced biochars with comparatively high mirco nutrient content. In conclusion the tested kiln, yields a useful bio-char and the potential for improvements in the kiln design with respect to char quality are rather limited.