The researchers studied how hazelnut shells can be turned into xylose and furfural through a process called hydrothermal pretreatment. They found that heating hazelnut shells at 160°C for 15 minutes can start the production of furfural. The best results were achieved at 200°C for 30 minutes, with the highest furfural production being 1.25 mg/ml. Xylose and acetic acid also increased with temperature and time, reaching maximum levels of 1.36 mg/ml and 3.25 mg/ml, respectively, at the same conditions.