Characterization of Biochar Produced from Various Organic Wastes by Vacuum Pyrolysis for Use as a Soil Amendment
A.G. Hardie and M. Carrier (Dept. Process Engineering, Stellenbosch University)
Facing the energy crisis, thermo-chemical processes such as pyrolysis and gasification in South Africa have become a topic of interest for conversion of cheap agricultural wastes into clean energy and valuable products. Vacuum pyrolysis differs from slow pyrolysis by removing vapours more quickly from the reaction zone and thus decreasing secondary reactions between gases and solid, resulting in increased oil yield. The bio-oil potentially represents a valuable liquid fuel for boilers, while its chemical composition suggests that it is a challenging matrix for isolation of chemical, nutritional and pharmaceutical products. The solid char fraction can be used as activated carbon for wastewater treatments purposes or as biochar for soil amendment.
The application of biochar to infertile, weathered and sandy soils merits attention due to the potential of improving the sustainability and fertility of these soils, and contributing to long-term C sequestration.
The aim of our project is to characterize biochar produced from vacuum pyrolysis of various organic wastes, including sugar cane bagasse, corn cobs, vineyard cuttings, olive, citrus and pear orchard prunings, and black wattle. The chemical and physical properties of biochar that affect soil fertility will be investigated.
The study will contribute to scientific knowledge that is important for soil fertility management and improving soil quality and C sequestration in South Africa. The findings of the research will benefit both commercial and subsistence agriculture in South Africa.
MSc Student: Umit Üras (Dept. Process Engineering)
Funding: Food Security Initiative, Stellenbosch University