The researchers found that using hot water and dilute acid can help break down poplar wood into sugars and lignin for biofuel production. By heating the wood to high temperatures and flowing water or acid through it, they were able to remove most of the solid material and convert xylan into xylose and cellulose into glucose. The highest yields were obtained at temperatures around 240-280°C. Enzymes were then used to further break down the remaining cellulose and xylooligomers into sugars. The study showed that the flow rate and temperature were crucial factors in the process, with dilute acid pretreatment resulting in higher sugar yields compared to water-only pretreatment.