Composition and Textural Characteristics of Char Powders Produced by Thermomechanical Processing of Sunflower Seed Husks

Abstract

The paper presents the results of experimental studies on the production of fine char powder from sunflower seed husks by a novel method of thermomechanical treatment with pulsed shock waves and supersonic jets of the mixture of ultra-superheated (above 2000 °C) steam and carbon dioxide, as well as the results of examination of the produced char powder in terms of its chemical, phase, and granulometric composition and structural, morphological, and texture characteristics. The objective of the research is to explore the possibility of using the resulting char powder as a sorption-active material for organic substances. It is shown that the obtained char particles and their agglomerates have an average size of 20–30 nm and 12–24 µm, respectively, have the shape of disks and ellipsoids, consist mainly of amorphous carbon (up to 56 wt%) and oxygen (up to 42 wt%), and have a specific surface area of 1.1–1.7 m2/g. It is concluded that such a char powder can be used as an absorbent for organic substances when dried and deagglomerated.

Keywords

• pulsed detonation gun
• ultra-superheated steam and carbon dioxide
• agricultural waste
• waste recycling
• sunflower seed husk
• char powder