Researchers investigated how treating hazelnut shells with a low-temperature alkali solution can improve the production of ethanol. They found that using NaOH at 6% concentration, a solid to liquid ratio of 1:10, and a temperature of 30°C for 3 days resulted in the highest ethanol yield. This method increased the overall process efficiency for ethanol production, with a maximum ethanol yield of 40.71% and an overall process efficiency of 37.73 mg/g. The study showed that this pretreatment process can significantly enhance the production of ethanol from hazelnut shells.