Effect of feed source and pyrolysis conditions on sugarcane bagasse biochar

Authors: Lima, Isabel; HASS, AMIR - West Virginia University

Submitted to: Meeting Proceedings
Publication Type: Proceedings
Publication Acceptance Date: 3/13/2019
Publication Date: 11/6/2019
Citation: Lima, I., Hass, A. 2019. Effect of feed source and pyrolysis conditions on sugarcane bagasse biochar. In: Proceedings of the Advances in Sugar Crop Processing and Conversion 2018 Conference, May 15-18, 2018, New Orleans, Louisiana. 2:76-91.

Interpretive Summary: Processing of sugarcane in sugar mills yields approximately 30% bagasse, a fibrous waste material composed mostly of crushed cane stalks. While 80-90% of the bagasse used on site as fuel, the remaining portion can be converted into a value-added product. One such option is thermal conversion of bagasse into biochar, a solid, stable, carbon-rich product. Fresh and field-aged sugarcane bagasse and detrasher output material were use in a slow-pyrolysis system to produce biochar. The effect of feed source material and pyrolysis conditions (peak-temperature [350 – 800 °C], steam activation [at 800 °C]) on biochar properties and efficiency as sorbent for heavy metals were determined. Biochar properties were feedstock and pyrolysis conditions dependent. Biochar of fresh bagasse had the highest fixed carbon and surface area, while detrasher and field-aged bagasse biochars had the highest ash content. While the field aged biochars showed the highest affinity and capacity for metal sorption, the biochars showed limited ability to remove copper, cadmium, and lead from water.Detrasher output material and resulting biochars had the highest nitrogen content compare to the other feed sources and biochars. Ash content seemed to play a decisive role in metal sorption capacity of sugarcane bagasse biochars. Overall,old sugarcane bagasse feedstock demonstrated best performance in producing biochars of higher metal sorption capacity compared to fresh cane-trash or fresh bagasse.

Technical Abstract: Processing of sugarcane in sugar mills yields approximately 30% bagasse, a fibrous waste material composed mostly of crushed cane stalks. While 80-90% of the bagasse used on site as fuel, the remaining portion can be converted into a value-added product. One such option is thermal conversion of bagasse into biochar, a solid, stable, carbon-rich product. Fresh and field-aged sugarcane bagasse and detrasher output material were use in a slow-pyrolysis system to produce biochar. The effect of feed source material and pyrolysis conditions (peak-temperature [350 – 800 °C], steam activation [at 800 °C]) on biochar properties and efficiency as sorbent for heavy metals were determined. Biochar properties were feedstock and pyrolysis conditions dependent. Biochar of fresh bagasse had the highest fixed carbon and surface area, while detrasher and field-aged bagasse biochars had the highest ash content. While the field aged biochars showed the highest affinity and capacity for metal sorption, the biochars showed limited ability to remove copper, cadmium, and lead from water.Detrasher output material and resulting biochars had the highest nitrogen content compare to the other feed sources and biochars. Ash content seemed to play a decisive role in metal sorption capacity of sugarcane bagasse biochars. Overall,old sugarcane bagasse feedstock demonstrated best performance in producing biochars of higher metal sorption capacity compared to fresh cane-trash or fresh bagasse.