Sweet sorghum bagasse for production of biochar

Authors: Lima, Isabel; Bigner, Renee

Submitted to: Meeting Proceedings
Publication Type: Proceedings
Publication Acceptance Date: 4/1/2017
Publication Date: 6/28/2017
Citation: Lima, I., Bigner, R. 2017. Sweet sorghum bagasse for production of biochar. In: Proceedings for the Advances in Sugar Crop Processing and Conversion Conference, March 15-18, 2016, New Orleans, Louisiana. p. 327-339.

Interpretive Summary: Sweet sorghum bagasse is an untapped resourceful carbon rich material that can be converted into value-added biochars. These biochars can be applied to the field as soil amendment for soil health enhancement, improved soil carbon content, water holding capacity, soil drainage and aeration and crop yields. This study looked at four different varieties of sweet sorghum and processed their bagasse into low and high temperature biochars. The objective is to determine if there are key differences amongst the varieties and pyrolysis temperature in terms of resulting properties of the biochar. The feedstocks and respective biochars were chemically characterized for their nutrient content and several physico-chemical and adsorptive properties were determined in order to ascertain their potential use as either adsorbents, soil amendment materials, or as fuel sources and compared with other plant and refinery wastes. Benefits of using sweet sorghum bagasse as value-added material are expected to both sweet sorghum growers and processors through the production of value-added pyrolysis products as well as enhancing the sweet sorghum industry’s role in renewable energy markets.

Technical Abstract: Sweet sorghum bagasse is an untapped resourceful carbon-rich material that can be thermochemically converted into value-added biochars. These biochars can be applied to the field as soil amendment for soil health enhancement, improved soil carbon content, water holding capacity, soil drainage and aeration, and plant and sugar yields. This study looked at four different varieties of sweet sorghum and processed their bagasse into biochars at low and high temperature (350° and 700°C). The feedstocks and respective biochars were chemically characterized for their nutrient content and several physico-chemical and adsorptive properties were determined in order to ascertain their potential use as either adsorbents, soil amendment materials, or as fuel sources, and compared with other plant and refinery wastes. No major differences were observed amongst the varieties in terms of resulting properties of the biochar, however, pyrolysis temperature affected biochar properties. Fuel value, fixed carbon, ash content and surface area increased with pyrolysis temperature. However, low temperature biochars were better candidates as copper ion sorbents. Benefits of using sweet sorghum bagasse as value-added material are expected to help both sweet sorghum growers and processors through the production of value-added pyrolysis products, as well as enhancing the sweet sorghum industry’s role in renewable energy markets.