Integrated no‐cook and high gravity ethanol technology from cassava: laboratory‐to‐pilot scale toward sustainable and low‐energy biofuel production

A no‐cook or simultaneous liquefaction, saccharification, and fermentation technology at very high gravity using cassava flour at 270 g L −1 at ambient temperature for bio‐ethanol production was developed at both the lab scale (1 L) and pilot scale (1000 L) in this work. The effects of auxiliary enzymes, yeast nutrients, and different dosages of starch‐hydrolyzing enzymes on ethanol production were investigated. Supplementation with cellulase, β ‐glucanase, and complex yeast nutrients showed no significant improvement in ethanol yield. In contrast, increasing the dosages of Stargen 002 (a granular starch‐hydrolyzing enzyme containing α ‐amylase and glucoamylase) at 2565 GAU kg −1 cassava flour and Amigase Mega L (glucoamylase) at 1.05 g kg −1 significantly enhanced fermentation performance. Under these conditions, ethanol concentrations of 14.4 and 14.0% v/v were achieved at laboratory and pilot scales, corresponding to fermentation yields of 86 and 83.66%, respectively. The simultaneous liquefaction, saccharification, and fermentation–very high gravity process demonstrated clear economic and environmental benefits, with pilot‐scale water and energy consumption of 16.57 L and 8.48 MJ per liter of ethanol, respectively. Replacing 32% of grid electricity with biomass enabled greenhouse gas emissions to match those of conventional technology while preserving energy savings, with further substitution making the process environmentally superior. At an industrial scale, reduced cassava and electricity costs significantly improved profitability, lowering production costs to 0.642 USD L −1 ethanol. In addition, cassava‐based distiller's dried grains showed potential as an animal feed co‐product with high fiber content (28.97%) and a moderate protein content (13.26%), highlighting the integrated no‐cook very high gravity system as a promising pathway for sustainable bioethanol production and circular bioeconomy development in Vietnam, improving resource efficiency and circularity as well as supporting Vietnam's national strategies for renewable energy transition.