Technology valuation of cellulosic ethanol production by Kluyveromyces marxianus CCT 7735 from sweet sorghum bagasse at elevated temperatures

Abstract Technology valuation of cellulosic ethanol production by Kluyveromyces marxianus CCT 7735 based on the concepts of circular economy was investigated. After an acid-base pretreatment followed by saccharification at 50 °C for 72 h, the sweet sorghum hydrolysate was used to produce ethanol at three temperatures: 37, 42, and 45 °C. About 17.83 g/L of cellulosic ethanol was reached at 42 °C in 24 h, with a yield of 2769.8 L/hasorghum, almost double that obtained for corn straw. This was the best cellulosic ethanol production from sweet sorghum bagasse achieved by K. marxianus strain and, therefore, it was used in the technology valuation. This analysis was carried out through the application of the profit equation, in which the revenue corresponded to ethanol sales in the global market in 2020, and the costs were defined by the activity-based costing method. An integration between 1G and 2G ethanol production, without mixing material streams, was considered to improve the technology valuation analysis. As a result, the equivalent to 17.2% of the profit obtained with the sugarcane juice ethanol was achieved for the sweet sorghum bagasse. Therefore, the technology valuation indicated the potential of sweet sorghum bagasse in the biorefinery ethanol production.