Development of Bio-functional Materials from Agricultural/Forestry Processed Wastes using a Concept of Multi-utilization with Pyrolysis

Abstract

Pyrolysis of agricultural/forestry processed wastes (AFPW) is one approach that has been investigated to develop materials into products of higher value. This paper describes a concept of multi-utilization with pyrolysis under various conditions which has been extensively prepared for related bio-functional materials like biochar, charcoal and activated carbon (AC). The prepared materials were developed into products such as biochar as part of cultural media for agricultural production; charcoal or AC as a potential moisture-proof adsorbent for food use; and the AC as a kind of liquid absorption for water purification. The biochar was prepared from AFPW as a cultural media substrate. Cultural media with biochar can be applied to vegetable plug seedlings with functions including preserving moisture and fertility, offering oxygen to expand the roots. For a food moisture-proof adsorbent, bamboo and wood charcoals were refined into various ACs using physical activations. The hygroscopicity of the resulting AC was better than that of charcoals, and the water activity of the AC was from 0.45 to 0.46. In addition, water purifying AC used sorghum distillery residue with the method of physics activation with steam-activation, which meets the quality standard for drinking water in Taiwan. The above products are concerned with multi-utilization under various pyrolysis conditions which can be used as a reference for resource reutilization from AFPW and also as examples of bio-functional materials' ability to be implemented in a sustainable reuse of resources.